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The InterOceanMetal (IOM) joint organisation’s exploration licence relates to the area located within the Clarion-Clipperton Fracture Zone (CCZ) of the eastern central Pacific. The exploration area covers 75 000 km2 and consists of two sectors (B1 and B2). The B2 sector comprises two exploration blocks (H11 and H22), delineated as the most prospective areas. The article presents information based on the data collected during the IOM’s exploration expeditions. Data were obtained using the distance methods (bathymetry, side-scan sonar, profiler) and contact methods (box-corer, gravity corer and trawl sampling) of exploration. Exploration area’s lithology, stratigraphy, geotechnical properties and general characteristics of seabed sediments and polymetallic nodules are provided. Estimation of mineral resources was carried out using the geostatistical method of ordinary block kriging, supported by Yamamoto correction. Regarding the level of geological knowledge and confidence, the polymetallic nodule resources have been classified within the Inferred, and Indicated Resources categories of the CRIRSCO classification system. (Author.), The InterOceanMetal (IOM) joint organisation’s exploration licence relates to the area located within the Clarion-Clipperton Fracture Zone (CCZ) of the eastern central Pacific. The exploration area covers 75 000 km2 and consists of two sectors (B1 and B2). The B2 sector comprises two exploration blocks (H11 and H22), delineated as the most prospective areas. The article presents information based on the data collected during the IOM’s exploration expeditions. Data were obtained using the distance methods (bathymetry, side-scan sonar, profiler) and contact methods (box-corer, gravity corer and trawl sampling) of exploration. Exploration area’s lithology, stratigraphy, geotechnical properties and general characteristics of seabed sediments and polymetallic nodules are provided. Estimation of mineral resources was carried out using the geostatistical method of ordinary block kriging, supported by Yamamoto correction. Regarding the level of geological knowledge and confidence, the polymetallic nodule resources have been classified within the Inferred, and Indicated Resources categories of the CRIRSCO classification system. (Author.)

In the mineral exploration and extraction sector, one of the professional functions that has come under the greatest scrutiny over the past 60 years is the estimation of mineral resources and derivation of ore reserves. Various reporting codes have been created to ensure that appropriate estimations and derivations are prepared and reporteed by appropriately registered and experienced persons. However, inappropriate activity does still occur and has in extreme cases led to significant financial losses for mining companies and investors. A new approach is currently being applied by the Institute of Materials, Minerals and Mining to professionals active in this field of work, as membership or fellowship is not by itself sufficient ratification given that the Institute's scope extends beyond the minerals industry into the downstream materials sectors. A Mineral Reporting accreditation is therefore being developed for members and fellows, accompanied by a publicly available register so that the professional credentials may be verified in order to validate resource estimates. The accreditation will be awarded following a professional discussion interview to ascertain whether the applicant is familiar with resource/reserve reporting and the current CRIRSCO template codes and reporting standards. It will not of itself comfer Competent Person status but will identify those members and fellows who fulfill the professional requirements as FIMMM (MR) or MIMMM (MR)., In the mineral exploration and extraction sector, one of the professional functions that has come under the greatest scrutiny over the past 60 years is the estimation of mineral resources and derivation of ore reserves. Various reporting codes have been created to ensure that appropriate estimations and derivations are prepared and reporteed by appropriately registered and experienced persons. However, inappropriate activity does still occur and has in extreme cases led to significant financial losses for mining companies and investors. A new approach is currently being applied by the Institute of Materials, Minerals and Mining to professionals active in this field of work, as membership or fellowship is not by itself sufficient ratification given that the Institute's scope extends beyond the minerals industry into the downstream materials sectors. A Mineral Reporting accreditation is therefore being developed for members and fellows, accompanied by a publicly available register so that the professional credentials may be verified in order to validate resource estimates. The accreditation will be awarded following a professional discussion interview to ascertain whether the applicant is familiar with resource/reserve reporting and the current CRIRSCO template codes and reporting standards. It will not of itself comfer Competent Person status but will identify those members and fellows who fulfill the professional requirements as FIMMM (MR) or MIMMM (MR).

The Lassonde Curve provides a simple, idealised guide to the variation that may be expected in the relative market value of a publicly quoted, junior mining company as it proceeds through the various phases of its project life. The project is considered to have nine phases: concept generation, initial exploration, advanced exploration, evaluation, permitting and capex funding, construction and startup, production, closure and reclamation, and monitoring and remediation. The curve is often used in presentations to support the view that the company's project is at one of the two points where the company's market value is about to increase dramatically., The Lassonde Curve provides a simple, idealised guide to the variation that may be expected in the relative market value of a publicly quoted, junior mining company as it proceeds through the various phases of its project life. The project is considered to have nine phases: concept generation, initial exploration, advanced exploration, evaluation, permitting and capex funding, construction and startup, production, closure and reclamation, and monitoring and remediation. The curve is often used in presentations to support the view that the company's project is at one of the two points where the company's market value is about to increase dramatically.

For resource estimation, domains are interpreted in a deposit to define homogenous areas for grade estimation. The conventional approach is to interpret the domains and then to separately model the distribution of the grade (i.e. partial grades) within each domain. The problem is that independent modelling of partial grades ignores the cross-dependency that exists between the partial grades within the defined domains. In this study, an alternative is proposed first to model the grade domains using a stochastic approach and then to model the partial grades within each domain using a co-simulation algorithm that incorporates their cross-correlation structures. The proposed enhanced co-simulation methodology has been applied at an iron deposit and a single grade threshold. The case study shows that the enhanced co-simulation methodology is capable of reproducing the global statistics and spatial continuity characteristics of the partial grades and results in improved domaining, grade estimation and definition of ore. (Authors.), For resource estimation, domains are interpreted in a deposit to define homogenous areas for grade estimation. The conventional approach is to interpret the domains and then to separately model the distribution of the grade (i.e. partial grades) within each domain. The problem is that independent modelling of partial grades ignores the cross-dependency that exists between the partial grades within the defined domains. In this study, an alternative is proposed first to model the grade domains using a stochastic approach and then to model the partial grades within each domain using a co-simulation algorithm that incorporates their cross-correlation structures. The proposed enhanced co-simulation methodology has been applied at an iron deposit and a single grade threshold. The case study shows that the enhanced co-simulation methodology is capable of reproducing the global statistics and spatial continuity characteristics of the partial grades and results in improved domaining, grade estimation and definition of ore. (Authors.)

The incorporation of bulk density uncertainty for mineral resource and mineral reserves (MRMR) steps is very important in mine planning, with density determinations directly affecting the conversion of volumes to tonnages and ore grades to metal contents. A study has been carried out to measure and minimise the risks associated with the MRMR stages, including the density variability in mine planning. MRMR estimates using bulk density interpolated for each block of a deposit are compared with estimates that use the simple density samples mean. The estimated tonnages for the models were analysed along with the projected pit geometries, production schedule, and NPV analysis. Use of this approach with data from a Brazilian iron ore mine showed that resources and reserves are underestimated if the bulk density uncertainty is not considered. Mine design changes were observed, including 5% impact on the life-of-mine and 2% in NPV. There was found to be stronger effects on production results in areas with greater density reliability, suggesting that bulk density estimates have a greater impact in short-term mining than in long-term estimates., The incorporation of bulk density uncertainty for mineral resource and mineral reserves (MRMR) steps is very important in mine planning, with density determinations directly affecting the conversion of volumes to tonnages and ore grades to metal contents. A study has been carried out to measure and minimise the risks associated with the MRMR stages, including the density variability in mine planning. MRMR estimates using bulk density interpolated for each block of a deposit are compared with estimates that use the simple density samples mean. The estimated tonnages for the models were analysed along with the projected pit geometries, production schedule, and NPV analysis. Use of this approach with data from a Brazilian iron ore mine showed that resources and reserves are underestimated if the bulk density uncertainty is not considered. Mine design changes were observed, including 5% impact on the life-of-mine and 2% in NPV. There was found to be stronger effects on production results in areas with greater density reliability, suggesting that bulk density estimates have a greater impact in short-term mining than in long-term estimates.

An ensemble super learner (ESL) model is proposed as a new methodology for ore grade estimation. The model manages visual artefacts in prediction maps and incorporates anisotropy information in the estimation process. Data from a high-grade narrow-vein gold deposit is used to demonstrate the approach, and the results are compared to kriging and the super learner (SL) model. The results demonstrate that the ESL model manages artifacts in machine learning (ML) spatial estimation. It also provides better results than the kriging and SL model in terms of estimation accuracy., An ensemble super learner (ESL) model is proposed as a new methodology for ore grade estimation. The model manages visual artefacts in prediction maps and incorporates anisotropy information in the estimation process. Data from a high-grade narrow-vein gold deposit is used to demonstrate the approach, and the results are compared to kriging and the super learner (SL) model. The results demonstrate that the ESL model manages artifacts in machine learning (ML) spatial estimation. It also provides better results than the kriging and SL model in terms of estimation accuracy.

The data and inversion processing technique for tonnage calculation by constrained Cartesian cut-cell inversion is demonstrated using magnetic and gravity surveys of the defined extent of the region of the mined-out 18 000 000 t Hajjar polymetallic deposit in Morocco, presenting a great benefit in saving time while providing accurate and realistic results. The potential-field signatures of what are regarded to be geologically expressive features are sought within the magnetic and gravity data. The preliminary stage for tonnage calculation was residual anomaly processing and depth estimation of the orebody using spectral analysis. Progressing towards extracting the deposit signature, the method invested the gravity signature of the orebody with adequacy regarding the magnetic signature. Finally, the tonnage calculation was developed by constrained Cartesian cut cell inversion using Voxi Earth ModellingTM. The importance of the obtained results lies in their qualitative and quantitative accuracy, which add value to the governmental geological and geophysical survey., The data and inversion processing technique for tonnage calculation by constrained Cartesian cut-cell inversion is demonstrated using magnetic and gravity surveys of the defined extent of the region of the mined-out 18 000 000 t Hajjar polymetallic deposit in Morocco, presenting a great benefit in saving time while providing accurate and realistic results. The potential-field signatures of what are regarded to be geologically expressive features are sought within the magnetic and gravity data. The preliminary stage for tonnage calculation was residual anomaly processing and depth estimation of the orebody using spectral analysis. Progressing towards extracting the deposit signature, the method invested the gravity signature of the orebody with adequacy regarding the magnetic signature. Finally, the tonnage calculation was developed by constrained Cartesian cut cell inversion using Voxi Earth ModellingTM. The importance of the obtained results lies in their qualitative and quantitative accuracy, which add value to the governmental geological and geophysical survey.

The paper proposes the main principles of a new methodology to evaluate dimension stone (DS) mining projects and properties, along with some aspects of industrial minerals (IM) mining operations. This relates to the estimation of Resources and Reserves, based on CRIRSCO International Standard and Codes. A series of evaluation steps are described. This method, named VALSTONE, is based on the author’s 30 years of professional experience, evaluating more than 140 quarry projects in over 40 countries. Its principles are valid for any type of dimension stone material, all types and sizes of operation and for greenfield, exploration and operating projects. The method combines the classic financial valuation techniques currently used to determine the value of a mining asset, such as Net Present Value (NPV), Discounted Cash Flow, Earnings Before Interest, Taxes, Depreciation and Amortisation (EBITDA) multiples, Kilburn Method, and others with technical, market and other non-financial factors specific to the dimension stone and IM industries and to the project under evaluation. These are often not considered in the economic valuation. Consideration and evaluation of the non-financial project factors results in the introduction of a new factor: the Project Specific Factor (PSF), which considers and evaluates the most specific objective features of the particular company or property to be evaluated. A simply structured detailed Survey-Questionnaire to calculate the PSF is also proposed. This PSF could subsequently be used by the valuators in their financial valuation technique and formula. Among the non-financial factors used to derive the PSF the method considers the Modifying Factors applied to transform Resources into Reserves, particularly the Quality Factor (QF) and the Joint Factor (JF) that represent the two key factors to determine the value of a dimension stone deposit., The paper proposes the main principles of a new methodology to evaluate dimension stone (DS) mining projects and properties, along with some aspects of industrial minerals (IM) mining operations. This relates to the estimation of Resources and Reserves, based on CRIRSCO International Standard and Codes. A series of evaluation steps are described. This method, named VALSTONE, is based on the author’s 30 years of professional experience, evaluating more than 140 quarry projects in over 40 countries. Its principles are valid for any type of dimension stone material, all types and sizes of operation and for greenfield, exploration and operating projects. The method combines the classic financial valuation techniques currently used to determine the value of a mining asset, such as Net Present Value (NPV), Discounted Cash Flow, Earnings Before Interest, Taxes, Depreciation and Amortisation (EBITDA) multiples, Kilburn Method, and others with technical, market and other non-financial factors specific to the dimension stone and IM industries and to the project under evaluation. These are often not considered in the economic valuation. Consideration and evaluation of the non-financial project factors results in the introduction of a new factor: the Project Specific Factor (PSF), which considers and evaluates the most specific objective features of the particular company or property to be evaluated. A simply structured detailed Survey-Questionnaire to calculate the PSF is also proposed. This PSF could subsequently be used by the valuators in their financial valuation technique and formula. Among the non-financial factors used to derive the PSF the method considers the Modifying Factors applied to transform Resources into Reserves, particularly the Quality Factor (QF) and the Joint Factor (JF) that represent the two key factors to determine the value of a dimension stone deposit.

Resource models traditionally use estimation parameters that are based on statistical patterns and spatial variability, and parameters tend to be generalised across a domain of blocks. Overly smooth grade models, however, restrict a mine planner's ability to achieve the best outcome for the project. Discussion is presented of the use of a set of more locally contextual parameters rather than the global parameter approach. The focus is on two aspects: optimising sample selection or search neighbourhood parameters (Local Kriging Neighbourhood Optimisation), and addressing topcuts in response to those samples selected. A case study is presented using data from an early stage narrow-vein high-grade gold project. It is concluded that in addition to the optimisation of search parameters, estimates can also be improved by considering the local variation conditions when applying a topcut. This would ensure that zones which are supported by several higher grades are not overly downgraded by a global topcut., Resource models traditionally use estimation parameters that are based on statistical patterns and spatial variability, and parameters tend to be generalised across a domain of blocks. Overly smooth grade models, however, restrict a mine planner's ability to achieve the best outcome for the project. Discussion is presented of the use of a set of more locally contextual parameters rather than the global parameter approach. The focus is on two aspects: optimising sample selection or search neighbourhood parameters (Local Kriging Neighbourhood Optimisation), and addressing topcuts in response to those samples selected. A case study is presented using data from an early stage narrow-vein high-grade gold project. It is concluded that in addition to the optimisation of search parameters, estimates can also be improved by considering the local variation conditions when applying a topcut. This would ensure that zones which are supported by several higher grades are not overly downgraded by a global topcut.

Turkey's reserve/resource reporting committee, UMREK, founded in 2016 to ensure that exploration and operating activities in mining areas are reported in accordance with international standards of materiality, competence and transparency, in 2018 became a member of the international reporting standards committee CRIRSCO and has developed its national reporting code to be compliant with the CRIRSCO international reporting template. The UMREK process to June 2018 is reported (p.1-23) with details of its regulations published in 2017 under Turkish investment and mining law, its tasks and authorisations, its working groups for legislation and reporting standards preparation and for training and certification, its committee members, and the establishment in December 2017 of the Association of Geosciences, Mining and Metallurgy Professionals (YERMAM). The two workshops held in January (p.24-93) and June 2017 (p.94-146) are reported with summaries of the various presentations on Turkish and international reporting bodies, initiatives and standards and inclusion of the views of a wide range of existing Turkish bodies: the banking sector, the Capital Market Board (SPK), the Istanbul Exchange, the Chamber of Geological Engineers, the Chamber of Mining Engineers, the Turkish Association of Economic Geologists and the Turkish Miners Association. The experiences of Mongolia, Brazil and Kazakhstan in joining CRIRSCO and adopting its standards are also reported and summaries are included of presentations on the history of resource/reserve estimation, the importance of mine planning and the possibilities of geometallurgical modelling., Turkey's reserve/resource reporting committee, UMREK, founded in 2016 to ensure that exploration and operating activities in mining areas are reported in accordance with international standards of materiality, competence and transparency, in 2018 became a member of the international reporting standards committee CRIRSCO and has developed its national reporting code to be compliant with the CRIRSCO international reporting template. The UMREK process to June 2018 is reported (p.1-23) with details of its regulations published in 2017 under Turkish investment and mining law, its tasks and authorisations, its working groups for legislation and reporting standards preparation and for training and certification, its committee members, and the establishment in December 2017 of the Association of Geosciences, Mining and Metallurgy Professionals (YERMAM). The two workshops held in January (p.24-93) and June 2017 (p.94-146) are reported with summaries of the various presentations on Turkish and international reporting bodies, initiatives and standards and inclusion of the views of a wide range of existing Turkish bodies: the banking sector, the Capital Market Board (SPK), the Istanbul Exchange, the Chamber of Geological Engineers, the Chamber of Mining Engineers, the Turkish Association of Economic Geologists and the Turkish Miners Association. The experiences of Mongolia, Brazil and Kazakhstan in joining CRIRSCO and adopting its standards are also reported and summaries are included of presentations on the history of resource/reserve estimation, the importance of mine planning and the possibilities of geometallurgical modelling.

Planning determines the optimum sequence of ore extraction but also aspects such as production rate and cut-off grade, shaft/drift locations and dimensions, direction and spacing of developments, types and number of transport units, hoisting, drainage, and stoping methods. At smaller mines these may not be dealt with by a single planning department but by line management, engineering and geology/surveying departments; other differences in planning at smaller mines are that they are generally more self-sufficient rather than relying on external contractors, they tend to use techniques specific to their smaller size, but their lower ore grades and decreasing economies of scale imply that they require higher standards of mine planning. The volume, by a consultant with diverse underground mining experience who saw the need for such an introduction, includes chapters addressing the following topics: the choice between surface and underground; types of ore reserve; access from surface; shaft planning; development planning; transport planning; hoisting choices; planning mine drainage; choice of stoping method; stope planning; speed and sequence of mining; and a brief appendix introducing emergency planning. In some sections a little background explanation has been inevitable but as far as possible only planning matters have been included, on the assumption that the reader already has a basic knowledge of underground mining. An important feature is the provision of intentionally simple line-drawn sketches such as engineers need to be able to produce, and the economic criteria used are the widely accepted net present value and internal rate of return as calculated by discounted cash-flow analysis. There is a brief list of references and a detailed subject index., 1 ind., Planning determines the optimum sequence of ore extraction but also aspects such as production rate and cut-off grade, shaft/drift locations and dimensions, direction and spacing of developments, types and number of transport units, hoisting, drainage, and stoping methods. At smaller mines these may not be dealt with by a single planning department but by line management, engineering and geology/surveying departments; other differences in planning at smaller mines are that they are generally more self-sufficient rather than relying on external contractors, they tend to use techniques specific to their smaller size, but their lower ore grades and decreasing economies of scale imply that they require higher standards of mine planning. The volume, by a consultant with diverse underground mining experience who saw the need for such an introduction, includes chapters addressing the following topics: the choice between surface and underground; types of ore reserve; access from surface; shaft planning; development planning; transport planning; hoisting choices; planning mine drainage; choice of stoping method; stope planning; speed and sequence of mining; and a brief appendix introducing emergency planning. In some sections a little background explanation has been inevitable but as far as possible only planning matters have been included, on the assumption that the reader already has a basic knowledge of underground mining. An important feature is the provision of intentionally simple line-drawn sketches such as engineers need to be able to produce, and the economic criteria used are the widely accepted net present value and internal rate of return as calculated by discounted cash-flow analysis. There is a brief list of references and a detailed subject index.

Lithium ores are potentially complex, including as Li-bearing phases lepidolite, the amblygonite-montebrusite group, lithiophosphate(tr) and petalite, and because its low atomic mass precludes direct electron-beam measurement analysing the Li content of whole rock is not straightforward with more than 10% difference sometimes noted between methods; an example compares spodumene pegmatite sampes from Kaustinen, Finland, analysed by 4-acid digestion versus Na2O2 flux then acid, both with ICP-AES finish. Whole-rock data are given from Kaustinen, the Goncalo lepidolite/Li phosphates in Portugal and the Cinavec Li-micas in Bohemia, advice on whole-rock procedure is summarised and cross-sections are presented of the Cinovec deposit's petrology, Sn and Li deposit contents and grade distribution block modelling; the Czech deposit is the largest low-cost hard-rock Li resource in Europe with 7 000 000 tonnes indicated and inferred lithium carbonate equivalent resources at 0.1% Li cut-off, contained in an indicated 347 700 000 t at 0.45% Li2O, 0.04% Sn and an inferred 308 800 000 t at 0.39% Li2O, 0.04% Sn; the exploration target is 350 000 000-450 000 000 t at 0.39-0.47% Li2O. The mineralogical characterisation of the various Li minerals is illustrated and compared for EPMA, from which the values have to be recalculated using stoichiometry, and direct measurement by LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry), showing that the majority of minerals have a good analytical agreement between the methods but that lithiophosphate and bityite results both differ significantly while hectorite and jadarite give variable results. LIBS (laser-induced breakdown spectroscopy) gives data that has a reasonable correlation with the EPMA and ICP-MS data, considering the spatial sampling differences., Lithium ores are potentially complex, including as Li-bearing phases lepidolite, the amblygonite-montebrusite group, lithiophosphate(tr) and petalite, and because its low atomic mass precludes direct electron-beam measurement analysing the Li content of whole rock is not straightforward with more than 10% difference sometimes noted between methods; an example compares spodumene pegmatite sampes from Kaustinen, Finland, analysed by 4-acid digestion versus Na2O2 flux then acid, both with ICP-AES finish. Whole-rock data are given from Kaustinen, the Goncalo lepidolite/Li phosphates in Portugal and the Cinavec Li-micas in Bohemia, advice on whole-rock procedure is summarised and cross-sections are presented of the Cinovec deposit's petrology, Sn and Li deposit contents and grade distribution block modelling; the Czech deposit is the largest low-cost hard-rock Li resource in Europe with 7 000 000 tonnes indicated and inferred lithium carbonate equivalent resources at 0.1% Li cut-off, contained in an indicated 347 700 000 t at 0.45% Li2O, 0.04% Sn and an inferred 308 800 000 t at 0.39% Li2O, 0.04% Sn; the exploration target is 350 000 000-450 000 000 t at 0.39-0.47% Li2O. The mineralogical characterisation of the various Li minerals is illustrated and compared for EPMA, from which the values have to be recalculated using stoichiometry, and direct measurement by LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry), showing that the majority of minerals have a good analytical agreement between the methods but that lithiophosphate and bityite results both differ significantly while hectorite and jadarite give variable results. LIBS (laser-induced breakdown spectroscopy) gives data that has a reasonable correlation with the EPMA and ICP-MS data, considering the spatial sampling differences.

The parallel development of the eastern/USSR and western systems of resource definitions and classifications and estimating rules and standards in the 20th century is traced, the independent development since the 1990s of the UN and CRIRSCO systems outlined and Turkey's move from the one to the other explained., The parallel development of the eastern/USSR and western systems of resource definitions and classifications and estimating rules and standards in the 20th century is traced, the independent development since the 1990s of the UN and CRIRSCO systems outlined and Turkey's move from the one to the other explained.

The paper's conclusions are summarised with emphasis on the reasons for failure, the results of not integrating the different technical disciplines involved, and the importance of collaboration and integration. Mine planning is crucial in order to have reliable, transparent, auditable and code-compatible mineral resources and reserves. Detailed feasibility studies in accordance with codes and standards need to be undertaken with sufficient time for accurate strategic and tactical decisions to be made. Database integration and interdisciplinary collaboration should be adopted as a basic principle at a time when technology is so strong in today's mining, and 3D mine planning software systems should also be widely used by engineers. Integration and sharing of different systems and software in today's mining has become very important., The paper's conclusions are summarised with emphasis on the reasons for failure, the results of not integrating the different technical disciplines involved, and the importance of collaboration and integration. Mine planning is crucial in order to have reliable, transparent, auditable and code-compatible mineral resources and reserves. Detailed feasibility studies in accordance with codes and standards need to be undertaken with sufficient time for accurate strategic and tactical decisions to be made. Database integration and interdisciplinary collaboration should be adopted as a basic principle at a time when technology is so strong in today's mining, and 3D mine planning software systems should also be widely used by engineers. Integration and sharing of different systems and software in today's mining has become very important.

The Olympic Dam Cu-U-Au-Ag deposit in South Australia is an iron oxide hosted copper-gold-uranium type deposit. Mineralisation is fine grained and typically disseminated within a haematite breccia hosted within the Roxby Downs granite. Ore is mined by mechanised sublevel longhole stoping; ROM ore is processed by bulk sulphide flotation to produce Cu concentration and flotation tailings which are leached to extract uranium. Large amounts of geometallurgical data have been collected and used throughout the planning life cycle. Discussion is presented of data extraction methods from the acQuire database, and the inclusion of a geometallurgy module in the Olympic Dam stope reserve database. The information is used in short-, medium- and long-term mine design and scheduling, including grade descriptor development and stope value assessment tools. A case study of one stope within the mine is used to illustrate the geometallurgical methods. It is important that a robust organisational structure is in place so that management understand the value of geometallurgical information in the planning process., The Olympic Dam Cu-U-Au-Ag deposit in South Australia is an iron oxide hosted copper-gold-uranium type deposit. Mineralisation is fine grained and typically disseminated within a haematite breccia hosted within the Roxby Downs granite. Ore is mined by mechanised sublevel longhole stoping; ROM ore is processed by bulk sulphide flotation to produce Cu concentration and flotation tailings which are leached to extract uranium. Large amounts of geometallurgical data have been collected and used throughout the planning life cycle. Discussion is presented of data extraction methods from the acQuire database, and the inclusion of a geometallurgy module in the Olympic Dam stope reserve database. The information is used in short-, medium- and long-term mine design and scheduling, including grade descriptor development and stope value assessment tools. A case study of one stope within the mine is used to illustrate the geometallurgical methods. It is important that a robust organisational structure is in place so that management understand the value of geometallurgical information in the planning process.

Aspects of kaolin extraction at St Austell, Cornwall, UK, are analysed from a geometallurgical perspective. This requires in situ spatial domain characterisation, classification of ore types and their response to refining strategies, integrated planning of extraction and refining, and optimisation of production from economic and environmental perspectives. Discussion is presented of the use of geometallurgy in in-pit characterisation, kaolin extraction and refining, colour characterisation, and mine optimisation. Geostatistical practices for ore reserve estimation are discussed, along with variogram modelling. Reducing energy consumption is also an important aim of geometallurgy; for kaolin the majority of energy is consumed during drying in the final stages of refining., Aspects of kaolin extraction at St Austell, Cornwall, UK, are analysed from a geometallurgical perspective. This requires in situ spatial domain characterisation, classification of ore types and their response to refining strategies, integrated planning of extraction and refining, and optimisation of production from economic and environmental perspectives. Discussion is presented of the use of geometallurgy in in-pit characterisation, kaolin extraction and refining, colour characterisation, and mine optimisation. Geostatistical practices for ore reserve estimation are discussed, along with variogram modelling. Reducing energy consumption is also an important aim of geometallurgy; for kaolin the majority of energy is consumed during drying in the final stages of refining.

In the current mining industry downturn, geometallurgy is critical for determining orebody variability for mine planning to maximise short-term value. Strategic geometallurgy has a long-term focus that actively uses all relevant data that helps to predict processing performance (such as bench-scale metallurgical tests, mineralogy, geochemistry, and ore texture) to model spatial ore variability and metallurgical response throughout the life-of-mine. This will enable better resource definition, more optimal mine planning and scheduling, improved process design and sustained capital strategy. Value-realisation is gained by basing all these strategic decisions on spatial models that reflect the actual value of blocks in the model. Tactical geometallurgy has a short- to medium-term tactical focus that also uses the geometallurgical database but includes new data derived during ore control activities to inform allocation-to-destination decisions via the ore control process. This will allow improved efficiency in allocation of mining blocks as direct feed, stockpile or waste. This efficiency will be measured in terms of value and not grade. The key benefit is that ore control will then be planned and executed on the basis of realised value. A twofold systematic and holistic value-based geometallurgical process should be planned and implemented in an integrated manner., In the current mining industry downturn, geometallurgy is critical for determining orebody variability for mine planning to maximise short-term value. Strategic geometallurgy has a long-term focus that actively uses all relevant data that helps to predict processing performance (such as bench-scale metallurgical tests, mineralogy, geochemistry, and ore texture) to model spatial ore variability and metallurgical response throughout the life-of-mine. This will enable better resource definition, more optimal mine planning and scheduling, improved process design and sustained capital strategy. Value-realisation is gained by basing all these strategic decisions on spatial models that reflect the actual value of blocks in the model. Tactical geometallurgy has a short- to medium-term tactical focus that also uses the geometallurgical database but includes new data derived during ore control activities to inform allocation-to-destination decisions via the ore control process. This will allow improved efficiency in allocation of mining blocks as direct feed, stockpile or waste. This efficiency will be measured in terms of value and not grade. The key benefit is that ore control will then be planned and executed on the basis of realised value. A twofold systematic and holistic value-based geometallurgical process should be planned and implemented in an integrated manner.

The Salvador copper project in Chile has been operating a block/panel caving mine for more than 50 years. The extraction method results in dynamic mixing of ore and dilution, with some of the ore from the upper level remaining unmined and presenting an opportunity for extraction from the level below. The potential for an open-pit mine is currently being evaluated, including the extraction of the remnant post-block caving ore. A mixing method using the CA3D cellular automata algorithm approach was used to estimate the remnant ore with a sufficient level of confidence for it to be included as part of the open-pit reserve. A remnant block model was created using elements including the in situ block model, drawpoint layouts, historical production records and drawpoint extraction. Extraction simulations by month from 1959 to 2019 were completed using different mixing scenarios to replicate the tonnage and grade extracted. Good results were obtained for remnant model estimation using the algorithm as it is able to replicate historical extraction in a realistic manner while maintaining the real mine sequence and allows better depletion modelling within individual production blocks and between adjacent production blocks and levels. The calibration process provided a good set of mixing probabilities to be applied in different areas depending on the extraction method used. The CA3D model runs directly in the block model so that the depletion and mixing occurs in the block model while extraction is being completed, creating the remnant block model directly., The Salvador copper project in Chile has been operating a block/panel caving mine for more than 50 years. The extraction method results in dynamic mixing of ore and dilution, with some of the ore from the upper level remaining unmined and presenting an opportunity for extraction from the level below. The potential for an open-pit mine is currently being evaluated, including the extraction of the remnant post-block caving ore. A mixing method using the CA3D cellular automata algorithm approach was used to estimate the remnant ore with a sufficient level of confidence for it to be included as part of the open-pit reserve. A remnant block model was created using elements including the in situ block model, drawpoint layouts, historical production records and drawpoint extraction. Extraction simulations by month from 1959 to 2019 were completed using different mixing scenarios to replicate the tonnage and grade extracted. Good results were obtained for remnant model estimation using the algorithm as it is able to replicate historical extraction in a realistic manner while maintaining the real mine sequence and allows better depletion modelling within individual production blocks and between adjacent production blocks and levels. The calibration process provided a good set of mixing probabilities to be applied in different areas depending on the extraction method used. The CA3D model runs directly in the block model so that the depletion and mixing occurs in the block model while extraction is being completed, creating the remnant block model directly.

An overview is presented of the research issues in the quantification, modelling, estimation and simulation of geometallurgical variables and their integration into resource and planning models. Progress to date is discussed, along with some specific approaches that have been developed and implemented. An assessment of the remaining issues and challenges is also given with particular reference to problems of scale and non-linearity, sensed data, and integrated resource modelling and optimisation., An overview is presented of the research issues in the quantification, modelling, estimation and simulation of geometallurgical variables and their integration into resource and planning models. Progress to date is discussed, along with some specific approaches that have been developed and implemented. An assessment of the remaining issues and challenges is also given with particular reference to problems of scale and non-linearity, sensed data, and integrated resource modelling and optimisation.

In the early stages of mine development the resource model is often based on sparse sample data. This can simplify the resource model and smooth the grade distribution and so misrepresent an orebody's mineability and associated grades. High density resource sampling can be used in the estimation of economic minerals and accompanying contaminants to minimise the risk of misrepresenting the mineralogical characteristics, and hence the economic value, of a reserve. A conditional simulation method for developing a range of mineralogical distribution models is introduced. It combines a geostatistical analysis of available data with automated mine design software to provide a rigorous method for assessing the confidence in the mineralogical characterisation of the ore reserve. It is based on simulating possible mine plans based on the statistical characteristics of the available resource sample data. These plans are then assessed against high resolution resource models generated using a sequential Gaussian simulation method. The method gives confidence intervals for important characteristics of the ore reserve estimate relative to the actual resource. These confidence intervals are an objective and transparent measure important for assessing closure risks and represent an improvement over common practice., In the early stages of mine development the resource model is often based on sparse sample data. This can simplify the resource model and smooth the grade distribution and so misrepresent an orebody's mineability and associated grades. High density resource sampling can be used in the estimation of economic minerals and accompanying contaminants to minimise the risk of misrepresenting the mineralogical characteristics, and hence the economic value, of a reserve. A conditional simulation method for developing a range of mineralogical distribution models is introduced. It combines a geostatistical analysis of available data with automated mine design software to provide a rigorous method for assessing the confidence in the mineralogical characterisation of the ore reserve. It is based on simulating possible mine plans based on the statistical characteristics of the available resource sample data. These plans are then assessed against high resolution resource models generated using a sequential Gaussian simulation method. The method gives confidence intervals for important characteristics of the ore reserve estimate relative to the actual resource. These confidence intervals are an objective and transparent measure important for assessing closure risks and represent an improvement over common practice.

The financial model is an integral component of any project evaluation based on mineral resources, ore reserves and, at least internally, exploration targets. Many models are prepared by staff or consultants who are comfortable with a particular format that may be used for other purposes, but the end result may or may not succeed in providing a clear, accurate and sufficiently detailed view of the economic viability of a project. When preparing a model, the practitioner should take into account the interpretation and review, or audit, process. The less time and effort required by an auditor is reflected directly in the cost of the review process. A financial model will typically include title page and instruction, summary, mineral resources, ore reserves and mining inventory, physical inputs and schedules, cash flow inputs and schedules, statutory financials if required and applicable, and sensitivity analyses. A number of suggestions are presented relating to the creation of the model, which should be based on a system which is in wide circulation and is known and familiar to likely auditors, is transparent with respect to inputs, calculations and outputs, and permits the auditor to modify inputs and calculations without destroying the integrity of the model., The financial model is an integral component of any project evaluation based on mineral resources, ore reserves and, at least internally, exploration targets. Many models are prepared by staff or consultants who are comfortable with a particular format that may be used for other purposes, but the end result may or may not succeed in providing a clear, accurate and sufficiently detailed view of the economic viability of a project. When preparing a model, the practitioner should take into account the interpretation and review, or audit, process. The less time and effort required by an auditor is reflected directly in the cost of the review process. A financial model will typically include title page and instruction, summary, mineral resources, ore reserves and mining inventory, physical inputs and schedules, cash flow inputs and schedules, statutory financials if required and applicable, and sensitivity analyses. A number of suggestions are presented relating to the creation of the model, which should be based on a system which is in wide circulation and is known and familiar to likely auditors, is transparent with respect to inputs, calculations and outputs, and permits the auditor to modify inputs and calculations without destroying the integrity of the model.

There is a discrepancy between U3O8 values derived from geochemical analysis of drill core samples and those derived from de-convolved gamma probe data at the Wiluna uranium Project in Western Australia. Using linear regression to create trend lines through the correlated data results in a relationship that would suggest that on average, U3O8 from geochemistry is up to 65% greater than U3O8 from the equivalent composited gamma data. Closed-can disequilibrium analysis on selected samples suggests that whilst positive disequilibrium may be contributing to the observed difference in some samples, the relationship is poor and does not account for the magnitude of the difference observed. The difference extends into block model comparisons across all of the Wiluna Project's resources. Testing shows that the geochemical analytical technique being used is not responsible. It is thought that the gamma probes are having difficulty measuring all of the radiation being emitted from uranium mineralisation within the particular geological setting of the Wiluna Project. Electrical logs and gamma gamma density data do not show any definitive relationship to the magnitude of the underestimation by the gamma probe, a reasonable correlation between this underestimation and sodium values derived from geochemical analysis may suggest a clay and/or groundwater salinity link., There is a discrepancy between U3O8 values derived from geochemical analysis of drill core samples and those derived from de-convolved gamma probe data at the Wiluna uranium Project in Western Australia. Using linear regression to create trend lines through the correlated data results in a relationship that would suggest that on average, U3O8 from geochemistry is up to 65% greater than U3O8 from the equivalent composited gamma data. Closed-can disequilibrium analysis on selected samples suggests that whilst positive disequilibrium may be contributing to the observed difference in some samples, the relationship is poor and does not account for the magnitude of the difference observed. The difference extends into block model comparisons across all of the Wiluna Project's resources. Testing shows that the geochemical analytical technique being used is not responsible. It is thought that the gamma probes are having difficulty measuring all of the radiation being emitted from uranium mineralisation within the particular geological setting of the Wiluna Project. Electrical logs and gamma gamma density data do not show any definitive relationship to the magnitude of the underestimation by the gamma probe, a reasonable correlation between this underestimation and sodium values derived from geochemical analysis may suggest a clay and/or groundwater salinity link.

The Productora deposit is a porphyry-copper style deposit with chalcopyrite as the main ore. It can be exploited using open pit mining, with preparation of a saleable concentrate from fresh ore as well as heap leaching, solvent extraction and electrowinning of copper from oxide ores. A geometallurgical model was developed during the prefeasibility study to predict the process responses of both sulphide and oxide ores. The model incorporates test results from mineralogical, metallurgical, and comminution testing, as well as other studies from samples collected from the deposit. The variability of sulphide ore throughput and comminution costs were estimated using Bond Work Index and Abrasion Index proxies in the geometallurgical model. Heap leach acid consumption in oxide ore was estimated from drill hole calcium concentrations. The model was then used in mine scheduling to identify high- and low-throughput or high- and low-acid ore zones so that the processing of these zones could be advanced or deferred to improve net present value. The cost benefits of preparing an early-stage geometallurgy model were quantified through a comparison with a conventional model based on test work averages., The Productora deposit is a porphyry-copper style deposit with chalcopyrite as the main ore. It can be exploited using open pit mining, with preparation of a saleable concentrate from fresh ore as well as heap leaching, solvent extraction and electrowinning of copper from oxide ores. A geometallurgical model was developed during the prefeasibility study to predict the process responses of both sulphide and oxide ores. The model incorporates test results from mineralogical, metallurgical, and comminution testing, as well as other studies from samples collected from the deposit. The variability of sulphide ore throughput and comminution costs were estimated using Bond Work Index and Abrasion Index proxies in the geometallurgical model. Heap leach acid consumption in oxide ore was estimated from drill hole calcium concentrations. The model was then used in mine scheduling to identify high- and low-throughput or high- and low-acid ore zones so that the processing of these zones could be advanced or deferred to improve net present value. The cost benefits of preparing an early-stage geometallurgy model were quantified through a comparison with a conventional model based on test work averages.

The Honeymoon uranium project in South Australia consists of 2 600 km2 of exploration tenements and a granted mining licence and is highly prospective for high-grade uranium mineralisation hosted within the Palaeocene Eyre Formation palaeochannel sediments. Historical and more recent exploration data has been amalgamated into a single database and GIS package and, as a result of the ongoing geological review, updated JORC resources have been declared. Resource updates were focused on creating a combined 3D lithological/geological and grade model for regions of contiguous mineralisation. The 3D model combined the Honeymoon, Brooks Dam, East Kalkaroo, Gould Dam and Billeroo Deposits. Grade domaining was undertaking using both traditional polygonal methods and indicator grade shells. Modelling of the spatial distribution of the uranium mineralisation was carried out using ordinary kriging, with localised uniform condition (LUC) undertaken to report the grade tonnage relationships at the level of the selective mining unit. The short-term focus is to define resources within the Jasons project region which is thought to host high-grade mineralisation. Combined measured, indicated and inferred resources are 37 300 000 t at 640 ppm eU3O8 for 23 800 000 kg of contained U3O8 at a 250 ppm eU3O8 lower cut off., The Honeymoon uranium project in South Australia consists of 2 600 km2 of exploration tenements and a granted mining licence and is highly prospective for high-grade uranium mineralisation hosted within the Palaeocene Eyre Formation palaeochannel sediments. Historical and more recent exploration data has been amalgamated into a single database and GIS package and, as a result of the ongoing geological review, updated JORC resources have been declared. Resource updates were focused on creating a combined 3D lithological/geological and grade model for regions of contiguous mineralisation. The 3D model combined the Honeymoon, Brooks Dam, East Kalkaroo, Gould Dam and Billeroo Deposits. Grade domaining was undertaking using both traditional polygonal methods and indicator grade shells. Modelling of the spatial distribution of the uranium mineralisation was carried out using ordinary kriging, with localised uniform condition (LUC) undertaken to report the grade tonnage relationships at the level of the selective mining unit. The short-term focus is to define resources within the Jasons project region which is thought to host high-grade mineralisation. Combined measured, indicated and inferred resources are 37 300 000 t at 640 ppm eU3O8 for 23 800 000 kg of contained U3O8 at a 250 ppm eU3O8 lower cut off.

Since mining finished at the Ranger 1, No 3 deposit (Northern Territory, Australia) in November 2012, the mine has been producing uranium oxide from lower-grade primary and laterite stockpiles which have accumulated since the mine opened in 1981. Mining and scheduling of remaining stockpiled reserves and resources has been carried out using a robust, regularly updated three dimensional stockpile resource model. Quarterly updates of stockpile changes form the basis of annual resource and reserve reporting. A recent lowering of the economic cut-off grade from 0.08% to 0.06% uranium oxide has resulted in larger mining stages that have optimised ore recovery, increased the ore reserve and extended mine life. The new reserve model balances the requirements of life-of-mine ore scheduling, detailed sequencing for backfill and rehabilitation to an approved radiological profile in the final rehabilitated landform. Discussion is presented of: stockpile model drilling history and development; use of innovative in-house developed MapInfo Visual Basic scripts to reset low precision GPS truckload elevation coordinates to the surveyed load elevation; block grade versus radiometric discriminator reconciliation results by mining stage; life-of-mine optimisation by mining stage to deliver grade to the mill by 2020; high level logic behind scheduling of low-grade and waste; and rehabilitation to an approved final landform., Since mining finished at the Ranger 1, No 3 deposit (Northern Territory, Australia) in November 2012, the mine has been producing uranium oxide from lower-grade primary and laterite stockpiles which have accumulated since the mine opened in 1981. Mining and scheduling of remaining stockpiled reserves and resources has been carried out using a robust, regularly updated three dimensional stockpile resource model. Quarterly updates of stockpile changes form the basis of annual resource and reserve reporting. A recent lowering of the economic cut-off grade from 0.08% to 0.06% uranium oxide has resulted in larger mining stages that have optimised ore recovery, increased the ore reserve and extended mine life. The new reserve model balances the requirements of life-of-mine ore scheduling, detailed sequencing for backfill and rehabilitation to an approved radiological profile in the final rehabilitated landform. Discussion is presented of: stockpile model drilling history and development; use of innovative in-house developed MapInfo Visual Basic scripts to reset low precision GPS truckload elevation coordinates to the surveyed load elevation; block grade versus radiometric discriminator reconciliation results by mining stage; life-of-mine optimisation by mining stage to deliver grade to the mill by 2020; high level logic behind scheduling of low-grade and waste; and rehabilitation to an approved final landform.

A model of resources and reserves (RR) estimation assurance has been effectively used in some mining companies to provide the audit committee with the required assurance of the RR processes. The approach ties the assurance needs of the audit committee to the needs of the technical experts and offers assurance providers with a model to audit through the RR processes. Discussion is presented of top-down and bottom-up approaches that provide assurance at different levels and a hybrid model of the two is described which meets the needs of diverse stakeholders. This model combines the expertise of professionals in both internal audit and RR. Implementation of the reporting mechanism is important, and an assurance processes aimed at continuous improvement enhances the robustness and reliability of the RR reported., A model of resources and reserves (RR) estimation assurance has been effectively used in some mining companies to provide the audit committee with the required assurance of the RR processes. The approach ties the assurance needs of the audit committee to the needs of the technical experts and offers assurance providers with a model to audit through the RR processes. Discussion is presented of top-down and bottom-up approaches that provide assurance at different levels and a hybrid model of the two is described which meets the needs of diverse stakeholders. This model combines the expertise of professionals in both internal audit and RR. Implementation of the reporting mechanism is important, and an assurance processes aimed at continuous improvement enhances the robustness and reliability of the RR reported.

Only small errors in the inputs are required to cause a large portion of an ore reserves estimate to have negative value, due to the preponderance of marginal-value material in many ore reserves estimates that rely on the use of a break-even cut-off grade. In some cases, rounding errors alone can result in a significant percentage of an ore reserve having negative value. An ore reserves estimate containing negative-value tonnages can still legitimately be called an ore reserve under the definition of the JORC Code (2012) if it is still economic as a whole, but negatively geared ore reserves will put a company at greater financial risk should commodity prices fall. The most common errors leading to negatively geared ore reserves include the assumption of a fixed processing recovery down to an inappropriate low grade, ignoring real laboratory or operational data, using median or modal values rather than mean values for parameters informing the analysis of the cut-off grade, cost errors, cost omissions, such as ignoring sustaining capital, and deliberate aggressiveness by companies to increase the ore reserve size without new discoveries. The ore reserves estimate should ideally be based on a cut-off grade that maximises the value objective of an organisation, such as net present value, but if a break-even cut-off grade must be used, it is essential that the cut-off grade calculation is undertaken using the best available data, preferably based on actual operation or suitably modified laboratory data, and a full set of cost data, including all contributory costs., Only small errors in the inputs are required to cause a large portion of an ore reserves estimate to have negative value, due to the preponderance of marginal-value material in many ore reserves estimates that rely on the use of a break-even cut-off grade. In some cases, rounding errors alone can result in a significant percentage of an ore reserve having negative value. An ore reserves estimate containing negative-value tonnages can still legitimately be called an ore reserve under the definition of the JORC Code (2012) if it is still economic as a whole, but negatively geared ore reserves will put a company at greater financial risk should commodity prices fall. The most common errors leading to negatively geared ore reserves include the assumption of a fixed processing recovery down to an inappropriate low grade, ignoring real laboratory or operational data, using median or modal values rather than mean values for parameters informing the analysis of the cut-off grade, cost errors, cost omissions, such as ignoring sustaining capital, and deliberate aggressiveness by companies to increase the ore reserve size without new discoveries. The ore reserves estimate should ideally be based on a cut-off grade that maximises the value objective of an organisation, such as net present value, but if a break-even cut-off grade must be used, it is essential that the cut-off grade calculation is undertaken using the best available data, preferably based on actual operation or suitably modified laboratory data, and a full set of cost data, including all contributory costs.

As of 1 December 2014, the 2012 edition of the JORC Code requires ore reserves to be defined by studies at the pre-feasibility or feasibility level. The definition of a pre-feasibility study provided in the code is that it is a comprehensive study into a range of options for the technical and economic viability of a mineral project. In practice, the requirement to undertake a pre-feasibility study in support of an ore reserve statement creates time pressure on those undertaking the study, which may reduce the comprehensiveness of the study of options and has the potential to leave significant potential value unrealised. The way in which the pathway for most mining developments is determined in the pre-feasibility study is discussed, and how a trade-off must be made between the need to make the best decision, the constraints of limited time and resources and the level of the project’s accuracy and uncertainty in terms of value is considered. Issues include framing the scope of the study, planning for robust decision-making and ensuring effective communication between the diverse disciplines within the team. It may be appropriate to separately define the terms pre-feasibility study and preliminary feasibility study. The declaration of ore reserves may then require some form of feasibility study, either preliminary or final/definitive, which may or may not be based on an optimised development alternative. The sequence of studies could then be adjusted to suit the needs of the project owner, perhaps with an initial preliminary feasibility study to establish the ore reserve, followed by a pre-feasibility study to choose the development alternative and then a final feasibility study to define the project to the level necessary to achieve corporate approval and funding. This would separate the long-term maximisation of value through strategic optimisation from the initial creation of value through ore reserve reporting and diminish the need to compromise between the two., As of 1 December 2014, the 2012 edition of the JORC Code requires ore reserves to be defined by studies at the pre-feasibility or feasibility level. The definition of a pre-feasibility study provided in the code is that it is a comprehensive study into a range of options for the technical and economic viability of a mineral project. In practice, the requirement to undertake a pre-feasibility study in support of an ore reserve statement creates time pressure on those undertaking the study, which may reduce the comprehensiveness of the study of options and has the potential to leave significant potential value unrealised. The way in which the pathway for most mining developments is determined in the pre-feasibility study is discussed, and how a trade-off must be made between the need to make the best decision, the constraints of limited time and resources and the level of the project’s accuracy and uncertainty in terms of value is considered. Issues include framing the scope of the study, planning for robust decision-making and ensuring effective communication between the diverse disciplines within the team. It may be appropriate to separately define the terms pre-feasibility study and preliminary feasibility study. The declaration of ore reserves may then require some form of feasibility study, either preliminary or final/definitive, which may or may not be based on an optimised development alternative. The sequence of studies could then be adjusted to suit the needs of the project owner, perhaps with an initial preliminary feasibility study to establish the ore reserve, followed by a pre-feasibility study to choose the development alternative and then a final feasibility study to define the project to the level necessary to achieve corporate approval and funding. This would separate the long-term maximisation of value through strategic optimisation from the initial creation of value through ore reserve reporting and diminish the need to compromise between the two.

Heathgate Resources Pty produce uranium through in situ recovery (ISR), which is often compared to enhanced oil and gas recovery. ISR is unique for minerals production when compared to conventional mining methods, and as a result requires specialised software tools to manage the process. Heathgate uses PathCAD as the main software tool for the development of an ISR project. PathCAD has been developed over the last 30 years specifically for the ISR production of uranium and other minerals. The software has many functions for the various stages of a project's development. some of the key functions include: resources estimation, wellfield design, production forecasting, and plant optimisation. The software is continually modified and customised in order to improve work productivity and efficiency. (Authors.), Heathgate Resources Pty produce uranium through in situ recovery (ISR), which is often compared to enhanced oil and gas recovery. ISR is unique for minerals production when compared to conventional mining methods, and as a result requires specialised software tools to manage the process. Heathgate uses PathCAD as the main software tool for the development of an ISR project. PathCAD has been developed over the last 30 years specifically for the ISR production of uranium and other minerals. The software has many functions for the various stages of a project's development. some of the key functions include: resources estimation, wellfield design, production forecasting, and plant optimisation. The software is continually modified and customised in order to improve work productivity and efficiency. (Authors.)

The Arrow uranium deposit in Saskatchewan, Canada, has structurally controlled, basement-hosted mineralisation concealed beneath around 100 m of cover. Mineralisation is hosted in numerous stacked subvertical mylonitic structural zones and ancillary splay structures with a strike length of over 840 m, width of over 235 m, and depth of over 820 m. Mineralisation is open along strike, at depth, and potentially in other subparallel zones laterally and at depth. Four main mineralised shear zones have been delineated, containing multiple intercalated mineralised lenses with widths of 4-25 m. The maiden inferred mineral resource is 3 480 000 t at 2.63% U3O8 containing 91 770 t U3O8, using a cut-off grade of 0.25%. The deposit is the largest maiden resource, and the largest undeveloped uranium deposit, in the Athabasca Basin. Exploration in the area began in August 2013, Arrow was discovered in February 2014 and the initial resource assessment was completed less than two years later. This rapid development from discovery to resource was due to a development philosophy comprising wide step-out drilling along strike, with later infill, and use of accurate, highly cost-effective directional drilling to obtain several branches per parent hole. Environmental, geotechnical and metallurgical programs were initiated in late 2015 as development towards prefeasibility study., The Arrow uranium deposit in Saskatchewan, Canada, has structurally controlled, basement-hosted mineralisation concealed beneath around 100 m of cover. Mineralisation is hosted in numerous stacked subvertical mylonitic structural zones and ancillary splay structures with a strike length of over 840 m, width of over 235 m, and depth of over 820 m. Mineralisation is open along strike, at depth, and potentially in other subparallel zones laterally and at depth. Four main mineralised shear zones have been delineated, containing multiple intercalated mineralised lenses with widths of 4-25 m. The maiden inferred mineral resource is 3 480 000 t at 2.63% U3O8 containing 91 770 t U3O8, using a cut-off grade of 0.25%. The deposit is the largest maiden resource, and the largest undeveloped uranium deposit, in the Athabasca Basin. Exploration in the area began in August 2013, Arrow was discovered in February 2014 and the initial resource assessment was completed less than two years later. This rapid development from discovery to resource was due to a development philosophy comprising wide step-out drilling along strike, with later infill, and use of accurate, highly cost-effective directional drilling to obtain several branches per parent hole. Environmental, geotechnical and metallurgical programs were initiated in late 2015 as development towards prefeasibility study.

The resources industry has experienced a significant downturn after a period of strong, sustained growth and is currently facing capital austerity as projects fail to deliver to expectations. In response, the industry has experienced slowing investment and an increasing regulatory burden as stakeholders seek a greater understanding of mining project risks. Stakeholders, including investors, regulators and project owners, have responded with at times significantly negative commentary on the industry. The success and value of a project is driven by many inter-related technical aspects and assumptions such as geological uncertainty and grade estimation, geotechnical conditions, productivity and production rates, metallurgical characteristics/performance, social and environmental factors, basis and accuracy of cost estimates and forecast commodity prices, but there may be a failure to adequately communicate the technical aspects that drive the results of the studies. Canadian and Australian regulatory bodies have introduced and enforced tighter regulations on reporting standards and disclosure requirements. The Canadian NI 43-101, 2012 JORC Code and 2015 VALMIN Code are all mechanisms that should be used to improve the quality of information provided to inform the investor. The Australian Securities Exchange and Australian Securities and Investments Commission have introduced and enforced tighter regulations associated with the public release and reporting of the results of technical and techno-economic studies. Most operations routinely include inferred resources in internal mine plans, and investors typically make allowances for assumed conversion of the reported inferred component of mineral resource estimates, but the current regulations are somewhat ambiguous as to whether the potential value of inferred resources can be publicly reported. As investors seek to take advantage of the current stage in the investment cycle, the key challenge of the technical specialist, The resources industry has experienced a significant downturn after a period of strong, sustained growth and is currently facing capital austerity as projects fail to deliver to expectations. In response, the industry has experienced slowing investment and an increasing regulatory burden as stakeholders seek a greater understanding of mining project risks. Stakeholders, including investors, regulators and project owners, have responded with at times significantly negative commentary on the industry. The success and value of a project is driven by many inter-related technical aspects and assumptions such as geological uncertainty and grade estimation, geotechnical conditions, productivity and production rates, metallurgical characteristics/performance, social and environmental factors, basis and accuracy of cost estimates and forecast commodity prices, but there may be a failure to adequately communicate the technical aspects that drive the results of the studies. Canadian and Australian regulatory bodies have introduced and enforced tighter regulations on reporting standards and disclosure requirements. The Canadian NI 43-101, 2012 JORC Code and 2015 VALMIN Code are all mechanisms that should be used to improve the quality of information provided to inform the investor. The Australian Securities Exchange and Australian Securities and Investments Commission have introduced and enforced tighter regulations associated with the public release and reporting of the results of technical and techno-economic studies. Most operations routinely include inferred resources in internal mine plans, and investors typically make allowances for assumed conversion of the reported inferred component of mineral resource estimates, but the current regulations are somewhat ambiguous as to whether the potential value of inferred resources can be publicly reported. As investors seek to take advantage of the current stage in the investment cycle, the key challenge of the technical specialist

Key issues which were considered when developing resource definition and mine planning strategies at the Olympic Dam polymetallic mine in South Australia are briefly discussed. A case study looking at a range of possible mining techniques for further development of the resource identified open pit, underground block cave, and underground open stoping as suitable methods. Strategic decisions that underpin resource development include: location and amount of drilling, information to be collected, which resource estimation method to use, and assumptions made during the reserving process. A second case study at Olympic Dam in areas of lower resource confidence was carried out to look at copper-equivalent grades in a section through the resource model, with one view using a model constructed using only surface drill holes to simulate an inferred level of resource confidence, and the other representing the same section using the current resource model at a measured level of confidence. Comparison of the models showed a much greater tonnage of high-grade resource in the measured resource model. The significance of this added value will be different for each mining method. It is concluded that the key to unlocking the potential value of a resource is to understand the mining and business consequences of initial decisions made in resource estimation., Key issues which were considered when developing resource definition and mine planning strategies at the Olympic Dam polymetallic mine in South Australia are briefly discussed. A case study looking at a range of possible mining techniques for further development of the resource identified open pit, underground block cave, and underground open stoping as suitable methods. Strategic decisions that underpin resource development include: location and amount of drilling, information to be collected, which resource estimation method to use, and assumptions made during the reserving process. A second case study at Olympic Dam in areas of lower resource confidence was carried out to look at copper-equivalent grades in a section through the resource model, with one view using a model constructed using only surface drill holes to simulate an inferred level of resource confidence, and the other representing the same section using the current resource model at a measured level of confidence. Comparison of the models showed a much greater tonnage of high-grade resource in the measured resource model. The significance of this added value will be different for each mining method. It is concluded that the key to unlocking the potential value of a resource is to understand the mining and business consequences of initial decisions made in resource estimation.

Investors and other stakeholders need to appreciate the project in its correct context when assessing the risk, opportunity and relative value associated with a resource project. Errors, omissions, biased reporting or conflicting information in project reporting may lead to a misinterpretation of technical and financial results, resulting in biased estimates or assumptions on project value. A simple combined resource project framework is described for presenting the status of a project which may be readily benchmarked against similar projects and to illustrate the stages required to advance the project outcomes to higher levels of certainty. The framework draws on definitions and guidelines readily available in various resource industry reporting codes and public company reporting requirements, and assesses three key areas for placing a resource project in its correct relative context: the project development stage; the confidence in the exploration results, mineral resources and/or ore reserves; and the level of accuracy, precision and confidence in the technical and economic studies supporting the reported results or options for the project. The framework is in the form of a table and makes use of three main axes to align the reporting intentions and expectations of the various codes. The vertical axis represents the increase in relative accuracy of the tonnage and grade/quality estimates of the exploration target, production target and resource and/or reserve as defined by the JORC Code and/or Australian Stock Exchange Chapter 5 listing rules. The horizontal axis at the top of the table represents the project development stages as defined by the VALMIN Code, and these are aligned along the bottom axis with the level or rigour of technical-economic assessment expected to support the reported material quantities and economic outcomes at a particular project development reporting stage. The framework provides a matrix of different reporting measures to cross-check t, Investors and other stakeholders need to appreciate the project in its correct context when assessing the risk, opportunity and relative value associated with a resource project. Errors, omissions, biased reporting or conflicting information in project reporting may lead to a misinterpretation of technical and financial results, resulting in biased estimates or assumptions on project value. A simple combined resource project framework is described for presenting the status of a project which may be readily benchmarked against similar projects and to illustrate the stages required to advance the project outcomes to higher levels of certainty. The framework draws on definitions and guidelines readily available in various resource industry reporting codes and public company reporting requirements, and assesses three key areas for placing a resource project in its correct relative context: the project development stage; the confidence in the exploration results, mineral resources and/or ore reserves; and the level of accuracy, precision and confidence in the technical and economic studies supporting the reported results or options for the project. The framework is in the form of a table and makes use of three main axes to align the reporting intentions and expectations of the various codes. The vertical axis represents the increase in relative accuracy of the tonnage and grade/quality estimates of the exploration target, production target and resource and/or reserve as defined by the JORC Code and/or Australian Stock Exchange Chapter 5 listing rules. The horizontal axis at the top of the table represents the project development stages as defined by the VALMIN Code, and these are aligned along the bottom axis with the level or rigour of technical-economic assessment expected to support the reported material quantities and economic outcomes at a particular project development reporting stage. The framework provides a matrix of different reporting measures to cross-check t

The radioactive equilibrium factor (REF) (the ratio between uranium and radium) is critical for mineral resource estimation based on gamma logging. It is determined from the chemical analysis of uranium and radium in 20-50% of intersections. Averaging REF for full deposit or for part of the deposit can lead to biased estimation of resources. Diffuse Ra haloes at the boundaries of mineralised intervals with shifted equilibrium towards an abundance of radium have a significant influence on the interpreted thickness of mineralised intersections. The boundaries of mineralised zones should therefore be defined using flexible radium concentration cut-offs. A correction for REF should be introduced to calculate uranium grade after establishing mineralised interval boundaries. REF studies should be carried out for the various geological/geochemical environments in and around the mineralised intervals. These REFs will depend on the average Ra grades or thicknesses of the mineralised intervals. Correct estimation of the REF allows unbiased estimation of U grades and mineral resources for different parts of deposits, as well as resolving some of the issues of U extraction from operational blocks., The radioactive equilibrium factor (REF) (the ratio between uranium and radium) is critical for mineral resource estimation based on gamma logging. It is determined from the chemical analysis of uranium and radium in 20-50% of intersections. Averaging REF for full deposit or for part of the deposit can lead to biased estimation of resources. Diffuse Ra haloes at the boundaries of mineralised intervals with shifted equilibrium towards an abundance of radium have a significant influence on the interpreted thickness of mineralised intersections. The boundaries of mineralised zones should therefore be defined using flexible radium concentration cut-offs. A correction for REF should be introduced to calculate uranium grade after establishing mineralised interval boundaries. REF studies should be carried out for the various geological/geochemical environments in and around the mineralised intervals. These REFs will depend on the average Ra grades or thicknesses of the mineralised intervals. Correct estimation of the REF allows unbiased estimation of U grades and mineral resources for different parts of deposits, as well as resolving some of the issues of U extraction from operational blocks.

The Aotea ironsand deposit is hosted in Pleistocene to Recent onshore dunes on the Aotea Peninsula, south of Raglan on the west coast of New Zealand's North Island. The deposit was discovered by Sinosteel Australia Pty Ltd in 2009 by drill testing magnetic anomalies identified from a regional aeromagnetic survey. Follow-up definition drilling established a maiden JORC resource estimate of 72 000 000 t in 2012. Since then, numerous phases of resource estimation have been carried out, and a detailed prefeasibility study was completed in 2014. In addition to the resource estimation and drilling, metallurgical testing, ground penetrating radar and ground magnetic surveying and interpretation, density studies, passive seismic and limited environmental and geotechnical work have also been carried out. Resource estimates in 2014 include a JORC Indicated and Inferred Resource of 202 000 000 t of ironsand, with an average grade of 14.6% magnetic concentrate (based on Davis Tube Recovery analysis) for a total of 29 500 000 t of magnetic concentrate with an average Fe grade of 53.1%. This resource is located immediately north of the original ironsand discovery made at Aotea in young dunes by the New Zealand Geological Survey in 1949, and does not include the area drilled by them. (Authors.), The Aotea ironsand deposit is hosted in Pleistocene to Recent onshore dunes on the Aotea Peninsula, south of Raglan on the west coast of New Zealand's North Island. The deposit was discovered by Sinosteel Australia Pty Ltd in 2009 by drill testing magnetic anomalies identified from a regional aeromagnetic survey. Follow-up definition drilling established a maiden JORC resource estimate of 72 000 000 t in 2012. Since then, numerous phases of resource estimation have been carried out, and a detailed prefeasibility study was completed in 2014. In addition to the resource estimation and drilling, metallurgical testing, ground penetrating radar and ground magnetic surveying and interpretation, density studies, passive seismic and limited environmental and geotechnical work have also been carried out. Resource estimates in 2014 include a JORC Indicated and Inferred Resource of 202 000 000 t of ironsand, with an average grade of 14.6% magnetic concentrate (based on Davis Tube Recovery analysis) for a total of 29 500 000 t of magnetic concentrate with an average Fe grade of 53.1%. This resource is located immediately north of the original ironsand discovery made at Aotea in young dunes by the New Zealand Geological Survey in 1949, and does not include the area drilled by them. (Authors.)

Quartz vein deposits at Waihi, New Zealand, were mined from 1883 to 1952, and from 1988 to the present. The total gold endowment of the vein system is estimated to be in excess of 10 000 000 oz Au, including the 8 5000 000 oz mined to 2015. The veins are hosted in Miocene andesites and were formed at around 6.1 Ma. The main historic mined areas were the Martha vein system (Martha, Welcome, Empire, Royal, Edward and Albert) and veins in the Union Hill area (Union and Amaranth). Modern exploration has discovered new vein systems including the blind systems of Favona-Moonlight and Correnso, and Trio within the Union Hill group. Exploration methods that can be used are constrained both by the depth of post-mineral cover and by the proximity of the residential area. Current near-mine exploration in Waihi relies on interpretation of available geological, geochemical and geophysical data sets, including drilling data, aeromagnetic, gravity and resistivity data. Overall, the Waihi vein system exhibits a magnetic depletion zone in aeromagnetic data coincident with a positive gravity anomaly in ground-based gravity survey data. Controlled source audio-frequency magnetotelluric pseudosections exhibit resistivity anomalies related to the vein systems and are an important exploration tool., Quartz vein deposits at Waihi, New Zealand, were mined from 1883 to 1952, and from 1988 to the present. The total gold endowment of the vein system is estimated to be in excess of 10 000 000 oz Au, including the 8 5000 000 oz mined to 2015. The veins are hosted in Miocene andesites and were formed at around 6.1 Ma. The main historic mined areas were the Martha vein system (Martha, Welcome, Empire, Royal, Edward and Albert) and veins in the Union Hill area (Union and Amaranth). Modern exploration has discovered new vein systems including the blind systems of Favona-Moonlight and Correnso, and Trio within the Union Hill group. Exploration methods that can be used are constrained both by the depth of post-mineral cover and by the proximity of the residential area. Current near-mine exploration in Waihi relies on interpretation of available geological, geochemical and geophysical data sets, including drilling data, aeromagnetic, gravity and resistivity data. Overall, the Waihi vein system exhibits a magnetic depletion zone in aeromagnetic data coincident with a positive gravity anomaly in ground-based gravity survey data. Controlled source audio-frequency magnetotelluric pseudosections exhibit resistivity anomalies related to the vein systems and are an important exploration tool.

Mineralisation at Sams Creek, New Zealand, occurs within a hydrothermally altered granite porphyry dyke up to 60 m thick which can be traced for 7 km. Exploration has focused on a 1 km section of the dyke; 130 diamond cored drill holes for a total of 19 244 m have been completed. The Main Zone is thought to contain over 1 000 000 oz of gold (20 000 000 t at 1.54 g/t Au) at a 0.7 g/t cut-off and around 600 000 oz of gold (7 500 000 t at 2.43 g/t Au) at a 1.5 g/t cut-off. The dyke has been modified by at least four alteration/mineralisation phases, with the main gold-bearing phase (Stage III) consisting of irregular to planar gold-bearing arsenopyrite-pyrite quartz veins which form sheeted and local stockwork vein complexes. The dyke has undergone 3 main phases of deformation and folding with the Stage III quartz veins probably forming along fold hinges and parallel boudinaged necks of extending fold limbs. Recent U-Pb dating of primary zircons from the dyke and hydrothermal zircons from Stage III mineralised veins indicates an upper Early Cretaceous age for both dyke emplacement and the main gold-bearing hydrothermal event., Mineralisation at Sams Creek, New Zealand, occurs within a hydrothermally altered granite porphyry dyke up to 60 m thick which can be traced for 7 km. Exploration has focused on a 1 km section of the dyke; 130 diamond cored drill holes for a total of 19 244 m have been completed. The Main Zone is thought to contain over 1 000 000 oz of gold (20 000 000 t at 1.54 g/t Au) at a 0.7 g/t cut-off and around 600 000 oz of gold (7 500 000 t at 2.43 g/t Au) at a 1.5 g/t cut-off. The dyke has been modified by at least four alteration/mineralisation phases, with the main gold-bearing phase (Stage III) consisting of irregular to planar gold-bearing arsenopyrite-pyrite quartz veins which form sheeted and local stockwork vein complexes. The dyke has undergone 3 main phases of deformation and folding with the Stage III quartz veins probably forming along fold hinges and parallel boudinaged necks of extending fold limbs. Recent U-Pb dating of primary zircons from the dyke and hydrothermal zircons from Stage III mineralised veins indicates an upper Early Cretaceous age for both dyke emplacement and the main gold-bearing hydrothermal event.

s are presented from sessions on: Geology and geometallurgy (8pp., 5 abstracts); Integrated process modelling (5pp., 5 abstracts); Geometallurgy in practice (6pp., 6 abstracts); and Developments in geometallurgy (5pp., 5 abstracts). Topics include the characterisation and evaluation of porphyry and other Cu and Au deposits, the determination of possible processing routes that would allow the economic recovery of REE from heavy mineral sand and U from low-grade resources, and the modelling of complex geology with reference to hardness data so that the comminution behaviour of different zones can be predicted. Other abstracts include: Water/rock interactions and physicochemical controls on mineral processing - being predictive based on geology, by Kracht W., Lois P., Townley B. and Ortiz J.; Geology and the geometallurgical model - an early-stage matrix linking lithology to likely behaviour-based domain boundaries, by Cropp A., Hadler K., Parbhakar-Fox A. and Goodall W.; The application of geometallurgy at Anglo Asian Mining's Gedabek gold mine in Azerbaijan, by Monhemius J. and Hedjazi F.; Influence of iron ore mineralogy on sinter characteristics, by Basu S.; Determination of CaCO3 content in diatomite ores (by dual-energy X-ray transmission and laser-induced breakdown spectroscopy), by Guatame-Garcia A. and Buxton M.; Some thoughts on geometallurgy, by Harris M.; Geometallurgical tools and protocols for ARD (acid rock drainage) prediction, by Parbhakar-Fox A. and Lottermoser B.; Geometallurgy - SGS Geometallurgical Services' latest developments, by Hallewell M.; Geometallurgy for comminution studies, by Barratt D.J.; Geometallurgy in the industrial mineral sector, by Aasly K. and Ellefmo S.; Sampling and effects of sample mass on the determination of gravity-recoverable gold (GRG), by Dominy S.; Selective fragmentation using high-voltage breakage equipment, by van der Wielen K.P.; Chemical conversion of olivine and serpentine minerals into precursors for ca, s are presented from sessions on: Geology and geometallurgy (8pp., 5 abstracts); Integrated process modelling (5pp., 5 abstracts); Geometallurgy in practice (6pp., 6 abstracts); and Developments in geometallurgy (5pp., 5 abstracts). Topics include the characterisation and evaluation of porphyry and other Cu and Au deposits, the determination of possible processing routes that would allow the economic recovery of REE from heavy mineral sand and U from low-grade resources, and the modelling of complex geology with reference to hardness data so that the comminution behaviour of different zones can be predicted. Other abstracts include: Water/rock interactions and physicochemical controls on mineral processing - being predictive based on geology, by Kracht W., Lois P., Townley B. and Ortiz J.; Geology and the geometallurgical model - an early-stage matrix linking lithology to likely behaviour-based domain boundaries, by Cropp A., Hadler K., Parbhakar-Fox A. and Goodall W.; The application of geometallurgy at Anglo Asian Mining's Gedabek gold mine in Azerbaijan, by Monhemius J. and Hedjazi F.; Influence of iron ore mineralogy on sinter characteristics, by Basu S.; Determination of CaCO3 content in diatomite ores (by dual-energy X-ray transmission and laser-induced breakdown spectroscopy), by Guatame-Garcia A. and Buxton M.; Some thoughts on geometallurgy, by Harris M.; Geometallurgical tools and protocols for ARD (acid rock drainage) prediction, by Parbhakar-Fox A. and Lottermoser B.; Geometallurgy - SGS Geometallurgical Services' latest developments, by Hallewell M.; Geometallurgy for comminution studies, by Barratt D.J.; Geometallurgy in the industrial mineral sector, by Aasly K. and Ellefmo S.; Sampling and effects of sample mass on the determination of gravity-recoverable gold (GRG), by Dominy S.; Selective fragmentation using high-voltage breakage equipment, by van der Wielen K.P.; Chemical conversion of olivine and serpentine minerals into precursors for ca

Papers are presented in sections on: increasing value and productivity in unforgiving markets (3 papers), global optimisation of multiple operations and processes (3 papers), advances in conditional simulation for complex applications (6 papers), global optimisation applications (3 papers), aspects of open pit mine planning (5 papers), advances in optimisation of open pit and underground mining planning (7 papers), advances and applications in mine optimisation (6 papers), mine production scheduling, stockpiling and blending (6 papers), on the open pit to underground transition (2 papers), and strategic innovation and research needs (5 papers and 1 abstract). All papers have been abstracted separately., Papers are presented in sections on: increasing value and productivity in unforgiving markets (3 papers), global optimisation of multiple operations and processes (3 papers), advances in conditional simulation for complex applications (6 papers), global optimisation applications (3 papers), aspects of open pit mine planning (5 papers), advances in optimisation of open pit and underground mining planning (7 papers), advances and applications in mine optimisation (6 papers), mine production scheduling, stockpiling and blending (6 papers), on the open pit to underground transition (2 papers), and strategic innovation and research needs (5 papers and 1 abstract). All papers have been abstracted separately.

The Guide contains new papers along with some which are updates of items from the first edition and others which have been published elsewhere. New aspects covered include coal and industrial minerals, the latest modifying factors and the developing practice of geometallurgy. Papers are presented in chapters entitled: An overview and outline (3 papers); The resource database (10 papers); Geological interpretation and geological modelling (9 papers); Mineral resource estimation (9 papers); Non-resource inputs to estimation of ore reserves: the modifying factors (14 papers); Ore reserve estimation (7 papers); Risk in resource and reserve estimation (7 papers); Monitoring and exploiting the reserve (9 papers); and Classification and reporting (11 papers). Each chapter begins with an overview and all new papers (except the overviews) have been abstracted separately. The text of the JORC Code 2012 is given in an appendix and there are author and subject indexes., 2 ind., The Guide contains new papers along with some which are updates of items from the first edition and others which have been published elsewhere. New aspects covered include coal and industrial minerals, the latest modifying factors and the developing practice of geometallurgy. Papers are presented in chapters entitled: An overview and outline (3 papers); The resource database (10 papers); Geological interpretation and geological modelling (9 papers); Mineral resource estimation (9 papers); Non-resource inputs to estimation of ore reserves: the modifying factors (14 papers); Ore reserve estimation (7 papers); Risk in resource and reserve estimation (7 papers); Monitoring and exploiting the reserve (9 papers); and Classification and reporting (11 papers). Each chapter begins with an overview and all new papers (except the overviews) have been abstracted separately. The text of the JORC Code 2012 is given in an appendix and there are author and subject indexes.

The book provides a framework to the understanding of cut-off grades and mine planning, building from initial concepts and limited examples to more comprehensive models of cut-off theory and practice. Chapters included are: Establishing underlying principles; Break-even analysis - accounting for costs and prices; Mortimer's definitions - accounting for geology; Lane's methodology - accounting for system capacities; Mine strategy optimisation - accounting for everything; Cut-off derivation methodologies and their place in the overall min planning process; The mine strategy optimisation process; Specifying the grade descriptor; Goals and value measures; Valuation methods; Strategy optimisation and risk management; Optimisation methods; and Answering Misconceptions and objections. Each chapter concludes with a summary discussing and reinforcing the key issues. An appendix contains five case studies of cut-off optimisation: at an underground gold mine under an open pit, at two adjacent multilens gold deposits in a developing country, at an underground lead-zinc mine with poor returns, at a large base metal open pit, and at mineral sands deposits containing mixtures of heavy minerals., The book provides a framework to the understanding of cut-off grades and mine planning, building from initial concepts and limited examples to more comprehensive models of cut-off theory and practice. Chapters included are: Establishing underlying principles; Break-even analysis - accounting for costs and prices; Mortimer's definitions - accounting for geology; Lane's methodology - accounting for system capacities; Mine strategy optimisation - accounting for everything; Cut-off derivation methodologies and their place in the overall min planning process; The mine strategy optimisation process; Specifying the grade descriptor; Goals and value measures; Valuation methods; Strategy optimisation and risk management; Optimisation methods; and Answering Misconceptions and objections. Each chapter concludes with a summary discussing and reinforcing the key issues. An appendix contains five case studies of cut-off optimisation: at an underground gold mine under an open pit, at two adjacent multilens gold deposits in a developing country, at an underground lead-zinc mine with poor returns, at a large base metal open pit, and at mineral sands deposits containing mixtures of heavy minerals.

Uranium can be extracted from roll-front deposits using in situ recovery (ISR) methods. Mineralisation in the South Kazakhstan deposits is associated with a regional redox front that defines the boundary of a zone of stratabound oxidation in permeable sediments. The mineralised bodies comprise noses, wings and satellite (or residual) parts. The proportion of uranium to radium varies depending on location within the redox zone: U dominates in the nose parts and decreases in the wings, while Ra dominates in the residual bodies and forms halos. Geological modelling has been carried out to recognise the individual roll-fronts within separate horizons and the permeability of the host sequence, followed by geostatistical analysis, compositing, block modelling and grade estimation. It is important to use a metal accumulation index (grade x thickness, or GT) to define cut-offs for resource estimation in ISR deposits. A two-dimensional gridded model is generated for each wireframe in order to estimate GT, and each cell of this model is compared with a column of cells in the original (classical) block model to estimate the GT in three dimensions. Using this methodology, the average differences between resource estimates based on exploration drill holes and from production wells were less than 5%, whereas the classical approach commonly gave differences in the order of 20-90%., Uranium can be extracted from roll-front deposits using in situ recovery (ISR) methods. Mineralisation in the South Kazakhstan deposits is associated with a regional redox front that defines the boundary of a zone of stratabound oxidation in permeable sediments. The mineralised bodies comprise noses, wings and satellite (or residual) parts. The proportion of uranium to radium varies depending on location within the redox zone: U dominates in the nose parts and decreases in the wings, while Ra dominates in the residual bodies and forms halos. Geological modelling has been carried out to recognise the individual roll-fronts within separate horizons and the permeability of the host sequence, followed by geostatistical analysis, compositing, block modelling and grade estimation. It is important to use a metal accumulation index (grade x thickness, or GT) to define cut-offs for resource estimation in ISR deposits. A two-dimensional gridded model is generated for each wireframe in order to estimate GT, and each cell of this model is compared with a column of cells in the original (classical) block model to estimate the GT in three dimensions. Using this methodology, the average differences between resource estimates based on exploration drill holes and from production wells were less than 5%, whereas the classical approach commonly gave differences in the order of 20-90%.

The resource estimate for Manyingee (Western Australia) uses a combination of gamma logging, prompt fission neutron (PFN) logging and geochemical assays. The strengths of each of these three methods are combined to define the resource of 25 900 000 lb at a grade of 850 ppm U3O8, using a 250 ppm cut-off and greater than 0.2 m thickness. The result is a quick, cost-effective methodology to define the resource with the highest level of certainty. Manyingee is a roll-front style uranium deposit with mineralisation associated with five broad roll fronts confined to their own modelled stratigraphic horizon. Roll-front style deposits display disequilibrium between gamma radiation and actual uranium concentration due to different solubilities of uranium and its gamma emitting daughter products. Gamma logging is the data set used to define the mineralisation model at Manyingee, despite being an indirect indicator of U3O8. Disequilibrium associated with the model is corrected by using PFN technology and geochemistry. The calculated disequilibrium is compared against a series of geological categories for the dynamic play of the disequilibrium correction factor. (Author.), The resource estimate for Manyingee (Western Australia) uses a combination of gamma logging, prompt fission neutron (PFN) logging and geochemical assays. The strengths of each of these three methods are combined to define the resource of 25 900 000 lb at a grade of 850 ppm U3O8, using a 250 ppm cut-off and greater than 0.2 m thickness. The result is a quick, cost-effective methodology to define the resource with the highest level of certainty. Manyingee is a roll-front style uranium deposit with mineralisation associated with five broad roll fronts confined to their own modelled stratigraphic horizon. Roll-front style deposits display disequilibrium between gamma radiation and actual uranium concentration due to different solubilities of uranium and its gamma emitting daughter products. Gamma logging is the data set used to define the mineralisation model at Manyingee, despite being an indirect indicator of U3O8. Disequilibrium associated with the model is corrected by using PFN technology and geochemistry. The calculated disequilibrium is compared against a series of geological categories for the dynamic play of the disequilibrium correction factor. (Author.)

Rio Tinto's Pilbara operations in Western Australia supply iron ore blends worldwide for steel production. Changes in steel demand must be taken into account when evaluating or developing projects. Resource evaluation at Pilbara involves the use of over a thousand mine schedule geological models to study the results over 600 km of drilling each year. Factors which need to be considered include the best resource development strategy, how the options are constrained by product strategy, and the mine plan requirements for each time frame and customer. The Pilbara models need to evaluate up to 18 potential product options, using ore from around 730 pits at 93 mine sites, producing through 33 plants with variable cut-off grades and stockpile configurations. In-house and proprietary mine planning tools are used which employ heuristic solutions, linear programming, genetic algorithms and agent-oriented techniques to generate appropriate mine schedules. All models are stored and managed in a centralised database. The authorised models produced include planning parameters and metadata such as material type, geological strand, product predictions, dilution, recovery and metallurgical factors, and mining and processing production parameters., Rio Tinto's Pilbara operations in Western Australia supply iron ore blends worldwide for steel production. Changes in steel demand must be taken into account when evaluating or developing projects. Resource evaluation at Pilbara involves the use of over a thousand mine schedule geological models to study the results over 600 km of drilling each year. Factors which need to be considered include the best resource development strategy, how the options are constrained by product strategy, and the mine plan requirements for each time frame and customer. The Pilbara models need to evaluate up to 18 potential product options, using ore from around 730 pits at 93 mine sites, producing through 33 plants with variable cut-off grades and stockpile configurations. In-house and proprietary mine planning tools are used which employ heuristic solutions, linear programming, genetic algorithms and agent-oriented techniques to generate appropriate mine schedules. All models are stored and managed in a centralised database. The authorised models produced include planning parameters and metadata such as material type, geological strand, product predictions, dilution, recovery and metallurgical factors, and mining and processing production parameters.