Search

Structures and patterns in the Thetford mine harzburgite, Quebec, are reviewed using the geology of LAB chrysotile orebodies as a model. Structural aspects include north and north-east-striking faults and bendings in granite dykes which created tension zones favourable to chrysotile development in the neighbouring harzburgite. Serpentinisation patterns include primary pervasive mass serpentinisation and secondary complete serpentinisation which was superimposed on the primary event, affecting a few centimetres on each side of tension cracks. Cracks have developed in stockworks which can be characterised by the width and the orientation of each chrysotile vein. The north-striking faults extend outside the chrysotile belt in other structural zones of the Appalachians where they appear as important lineaments. Thetford mine is the oldest mining camp in Canada., Structures and patterns in the Thetford mine harzburgite, Quebec, are reviewed using the geology of LAB chrysotile orebodies as a model. Structural aspects include north and north-east-striking faults and bendings in granite dykes which created tension zones favourable to chrysotile development in the neighbouring harzburgite. Serpentinisation patterns include primary pervasive mass serpentinisation and secondary complete serpentinisation which was superimposed on the primary event, affecting a few centimetres on each side of tension cracks. Cracks have developed in stockworks which can be characterised by the width and the orientation of each chrysotile vein. The north-striking faults extend outside the chrysotile belt in other structural zones of the Appalachians where they appear as important lineaments. Thetford mine is the oldest mining camp in Canada.

The primary objectives of underground mine management systems are to maximise production and minimise contention time through allocated train and/or LHD dispatching, traffic control, equipment monitoring, and comprehensive reporting. The main components of an underground mine management system include a central computer in the system control centre and field computer systems on each train or LHD. Discussion is presented of a system based on leaky feeder cable radio communication to support data and voice communications concurrently. Underground mine management systems help maximise production by providing impressive gains in areas such as equipment and manpower utilisation, man tracking, draw point equalisation in block caving operations, preventive maintenance, and safety., The primary objectives of underground mine management systems are to maximise production and minimise contention time through allocated train and/or LHD dispatching, traffic control, equipment monitoring, and comprehensive reporting. The main components of an underground mine management system include a central computer in the system control centre and field computer systems on each train or LHD. Discussion is presented of a system based on leaky feeder cable radio communication to support data and voice communications concurrently. Underground mine management systems help maximise production by providing impressive gains in areas such as equipment and manpower utilisation, man tracking, draw point equalisation in block caving operations, preventive maintenance, and safety.

A ground support pull test system is used at the Noranda Technology Centre to field-test ground support. Field testing has already been accomplished with several different types of ground support. Test results can become part of an in-house ground support quality control programme and can also be used to examine the characteristics of new supports. Features of the pull test system include adaptability to a variety of ground support, high frequency reading rate, an independent displacement monitoring system, the development of bolt installation procedures and a quick, reliable facing system that provides a level seating surface for the hydraulic jack. Other ground support quality control initiatives include regular grout sampling kits to collect and monitor grout quality. A record of grout quality and laboratory uniaxial compressive strength testing over the years provides a good calibration curve for grout quality control., A ground support pull test system is used at the Noranda Technology Centre to field-test ground support. Field testing has already been accomplished with several different types of ground support. Test results can become part of an in-house ground support quality control programme and can also be used to examine the characteristics of new supports. Features of the pull test system include adaptability to a variety of ground support, high frequency reading rate, an independent displacement monitoring system, the development of bolt installation procedures and a quick, reliable facing system that provides a level seating surface for the hydraulic jack. Other ground support quality control initiatives include regular grout sampling kits to collect and monitor grout quality. A record of grout quality and laboratory uniaxial compressive strength testing over the years provides a good calibration curve for grout quality control.

SOQUEM and Norsk Hydro have defined a deposit of apatite, ilmenite and magnetite within the Sept-Iles layered mafic complex, Quebec. Marketable concentrates of apatite and ilmenite have been prepared in pilot plant tests. The apatite concentrate grades 40% P2O5; the ilmenite concentrate 47% TiO2. Apatite is used in the production of NPK-type fertilizers; the ilmenite is a sulphatable grade feedstock for the TiO2 pigment industry. A titanomagnetite concentrate of density 4.7 g/cm3 and grading 81.6% Fe2O3 has also been prepared. This product could be marketed as heavy media for mineral separation. Waste gabbro could be sold as aggregate. Other potential commodities are vanadium from the titanomagnetite and olivine. A probable reserve of 108 000 000 t at an average grade of 6.2% P2O5 and 8.4% TiO2 has been identified. The waste:ore ratio is 1.13:1. The capital costs for mine and mill total Can, SOQUEM and Norsk Hydro have defined a deposit of apatite, ilmenite and magnetite within the Sept-Iles layered mafic complex, Quebec. Marketable concentrates of apatite and ilmenite have been prepared in pilot plant tests. The apatite concentrate grades 40% P2O5; the ilmenite concentrate 47% TiO2. Apatite is used in the production of NPK-type fertilizers; the ilmenite is a sulphatable grade feedstock for the TiO2 pigment industry. A titanomagnetite concentrate of density 4.7 g/cm3 and grading 81.6% Fe2O3 has also been prepared. This product could be marketed as heavy media for mineral separation. Waste gabbro could be sold as aggregate. Other potential commodities are vanadium from the titanomagnetite and olivine. A probable reserve of 108 000 000 t at an average grade of 6.2% P2O5 and 8.4% TiO2 has been identified. The waste:ore ratio is 1.13:1. The capital costs for mine and mill total Can

In the past, slurry pump selection for heavy-duty service usually focused on low velocities inside large, slow running pumps aimed at reasonable wear as a main priority. The cost of power and the competitive nature of the market place in recent years have brought pressure for lower initial and operating cost at the expense of higher, or less certain, operating wear life. Until recently, estimating slurry pump wear life for a given set of operating conditions was an uncertain process. Technology now exists, however, to calculate the wear life of a slurry pump in service and this can be combined with the other operating costs to determine the total cost of ownership. Discussion is presented of the factors involved in the selection of a slurry pump, how the cost components, i.e. capital, electrical, wear and operating, can be calculated, and how these fit into the total cost of ownership., In the past, slurry pump selection for heavy-duty service usually focused on low velocities inside large, slow running pumps aimed at reasonable wear as a main priority. The cost of power and the competitive nature of the market place in recent years have brought pressure for lower initial and operating cost at the expense of higher, or less certain, operating wear life. Until recently, estimating slurry pump wear life for a given set of operating conditions was an uncertain process. Technology now exists, however, to calculate the wear life of a slurry pump in service and this can be combined with the other operating costs to determine the total cost of ownership. Discussion is presented of the factors involved in the selection of a slurry pump, how the cost components, i.e. capital, electrical, wear and operating, can be calculated, and how these fit into the total cost of ownership.

Mine tailings may be a valuable resource if effective treatment is used to recover target metals and stabilize or eliminate environmental contaminants. EMR's microwave process can be used to treat several types of refractory ores and concentrates including tailings from previous operations. For sulphidic materials such as pyrite/arsenopyrite this process yields a leachable calcine without the production of SO2 and As2O3. Where an ore's refractory nature results from encapsulation, as in the case of Mexican Au and Ag encased by hydroxides, the appropriate application of microwave power causes microfracturing and/or the release of the encapsulant. The process is described for treatment of two types of tailings: a Canadian pyrite/arsenopyrite material and a Mexican hydroxide encapsulation material. The pyrite/arsenopyrite material is oxidised to a haematite calcine which yields to conventional cyanidation. The goethite material is converted to haematite with the release of water. A detailed projection of capital and operating costs for these operations is presented., Mine tailings may be a valuable resource if effective treatment is used to recover target metals and stabilize or eliminate environmental contaminants. EMR's microwave process can be used to treat several types of refractory ores and concentrates including tailings from previous operations. For sulphidic materials such as pyrite/arsenopyrite this process yields a leachable calcine without the production of SO2 and As2O3. Where an ore's refractory nature results from encapsulation, as in the case of Mexican Au and Ag encased by hydroxides, the appropriate application of microwave power causes microfracturing and/or the release of the encapsulant. The process is described for treatment of two types of tailings: a Canadian pyrite/arsenopyrite material and a Mexican hydroxide encapsulation material. The pyrite/arsenopyrite material is oxidised to a haematite calcine which yields to conventional cyanidation. The goethite material is converted to haematite with the release of water. A detailed projection of capital and operating costs for these operations is presented.

Idle and abandoned properties can result in significant public safety, environmental and regulatory liabilities. A process is discussed by which these risks and liabilities can be managed cost effectively. A closure plan for the site usually has five basic elements: initial site delineation and liability assessment, development of a site specific property management programme, progressive rehabilitation, site inspection and monitoring, and a final audit. One of the most cost effective ways of implementing a programme is to engage a long-term property management services company to ensure that the closure is carried out in accordance with regulatory and corporate requirements. By combining risk assessment/management, closure planning and environmental management system techniques within the existing regulatory framework, a site specific and cost effective approach can be developed for an existing idle or abandoned mining property., Idle and abandoned properties can result in significant public safety, environmental and regulatory liabilities. A process is discussed by which these risks and liabilities can be managed cost effectively. A closure plan for the site usually has five basic elements: initial site delineation and liability assessment, development of a site specific property management programme, progressive rehabilitation, site inspection and monitoring, and a final audit. One of the most cost effective ways of implementing a programme is to engage a long-term property management services company to ensure that the closure is carried out in accordance with regulatory and corporate requirements. By combining risk assessment/management, closure planning and environmental management system techniques within the existing regulatory framework, a site specific and cost effective approach can be developed for an existing idle or abandoned mining property.

Geomechanical instrumentation has been used to evaluate the effects of mining on underground excavations at the waste isolation pilot plant near Carlsbad, New Mexico. The site is being developed for the disposal of transuranic nuclear wastes in bedded salt 655 m underground. During a recent mining sequence, increasing convergence rates were observed in a nearby drift ahead of the mining, separated from the mining area by a 45 m pillar. The situation was complicated by recent rib maintenance which had been performed in the nearby drift. The geomechanical data and numerical models were evaluated to determine the cause for increasing convergence rates, the effect of adjacent mining on nearby excavations and whether the minimal amount of trimming (less than 0.15 m) which occurred during rib maintenance activities affected convergence rates., Geomechanical instrumentation has been used to evaluate the effects of mining on underground excavations at the waste isolation pilot plant near Carlsbad, New Mexico. The site is being developed for the disposal of transuranic nuclear wastes in bedded salt 655 m underground. During a recent mining sequence, increasing convergence rates were observed in a nearby drift ahead of the mining, separated from the mining area by a 45 m pillar. The situation was complicated by recent rib maintenance which had been performed in the nearby drift. The geomechanical data and numerical models were evaluated to determine the cause for increasing convergence rates, the effect of adjacent mining on nearby excavations and whether the minimal amount of trimming (less than 0.15 m) which occurred during rib maintenance activities affected convergence rates.

The relationship between stope geometry, rock mass quality, blasting patterns and mining performance is very complex. Preliminary results at Louvicourt mine, Quebec, showed a significant trend between the size of an underground opening and its geometrical complexity. Neither the powder factor nor the rock mass quality can, by themselves, control stope performance. The influence of rock mass quality increases when there are important variations between different rock types. The performance of 58 stopes has been studied. Rock mass quality seemed to have less influence on stope performance than expected for fair to good quality rock. In poor quality rock, however, rock competence is the controlling factor. The ratio between the volume of a stope and its real surface area (RVS) is still a good indicator of stope geometry and can be linked to performance: beyond an RVS of 3 a significant reduction in performance is observed., The relationship between stope geometry, rock mass quality, blasting patterns and mining performance is very complex. Preliminary results at Louvicourt mine, Quebec, showed a significant trend between the size of an underground opening and its geometrical complexity. Neither the powder factor nor the rock mass quality can, by themselves, control stope performance. The influence of rock mass quality increases when there are important variations between different rock types. The performance of 58 stopes has been studied. Rock mass quality seemed to have less influence on stope performance than expected for fair to good quality rock. In poor quality rock, however, rock competence is the controlling factor. The ratio between the volume of a stope and its real surface area (RVS) is still a good indicator of stope geometry and can be linked to performance: beyond an RVS of 3 a significant reduction in performance is observed.

The NICO deposit contains a total inferred resource of 136 000 000 tonnes grading 0.071% Co, 0.543 g/t Au, 0.078% Bi and 0.052% Cu in the Bowl Zone, of which 88 600 000 t are measured and indicated. It includes a higher grade measured and indicated mineral resource of 60 000 000 t grading 0.10% Co, 0.77 g/t Au, 0.11% Bi and 0.05% Cu. The Sue-Dianne deposit contains a total resource of 17 000 000 t, including a measured and indicated mineral resource of 13 500 000 t, grading 0.78% Cu, 3.81 g/t Ag and 0.07 g/t Au, and a higher grade 8 700 000 t resource grading 1.00% Cu, 4.26 g/t Ag and 0.09 g/t Au. The deposits are the only known significant Canadian examples of Proterozoic iron oxide-hosted polymetallic deposits of the Olympic Dam type. Airborne and ground geophysical surveys identified coincident K, U, magnetic, resistivity, chargeability and gravity anomalies centred over the NICO and Sue-Dianne claims., The NICO deposit contains a total inferred resource of 136 000 000 tonnes grading 0.071% Co, 0.543 g/t Au, 0.078% Bi and 0.052% Cu in the Bowl Zone, of which 88 600 000 t are measured and indicated. It includes a higher grade measured and indicated mineral resource of 60 000 000 t grading 0.10% Co, 0.77 g/t Au, 0.11% Bi and 0.05% Cu. The Sue-Dianne deposit contains a total resource of 17 000 000 t, including a measured and indicated mineral resource of 13 500 000 t, grading 0.78% Cu, 3.81 g/t Ag and 0.07 g/t Au, and a higher grade 8 700 000 t resource grading 1.00% Cu, 4.26 g/t Ag and 0.09 g/t Au. The deposits are the only known significant Canadian examples of Proterozoic iron oxide-hosted polymetallic deposits of the Olympic Dam type. Airborne and ground geophysical surveys identified coincident K, U, magnetic, resistivity, chargeability and gravity anomalies centred over the NICO and Sue-Dianne claims.

Spatial statistics, or geostatistics, are commonly used in resource modelling, ore reserve estimation and grade control but have so far not been applied at the exploration stage, where there is little hard information such as drill hole data. When the discipline began, it was claimed that geostatisticians could define the optimum drilling grid for a deposit recognised by just a few drill holes. Given the escalating cost of drilling, this claim has attracted the attention of many exploration managers. In recent years, new simulation techniques have emerged that cast a new light on this old problem. Using the same case study, discussion is presented of the early answers of geostatistics along with results obtained from new simulation techniques. Other upstream geostatistical applications in exploration, such as filtering of surface geochemical data and anomaly recognition, are also briefly discussed., Spatial statistics, or geostatistics, are commonly used in resource modelling, ore reserve estimation and grade control but have so far not been applied at the exploration stage, where there is little hard information such as drill hole data. When the discipline began, it was claimed that geostatisticians could define the optimum drilling grid for a deposit recognised by just a few drill holes. Given the escalating cost of drilling, this claim has attracted the attention of many exploration managers. In recent years, new simulation techniques have emerged that cast a new light on this old problem. Using the same case study, discussion is presented of the early answers of geostatistics along with results obtained from new simulation techniques. Other upstream geostatistical applications in exploration, such as filtering of surface geochemical data and anomaly recognition, are also briefly discussed.

LKAB is automating two of the world's largest underground mines at Kiruna and Malmberget, Sweden. Computer-guided, large-scale automatic machines are being used. Four Atlas Copco drilling rigs are remotely operated from the control room on the 775 level. Later this year full scale tests of the operation and monitoring of autonomous LHDs (Tamrock Toro 2500) will be carried out. The automation network connecting the machine with the operator is based on two key technologies, a wireless high speed link for digital data, audio and video in real time and an ATM backbone network for data, audio and video transfer between the control room and the production areas., LKAB is automating two of the world's largest underground mines at Kiruna and Malmberget, Sweden. Computer-guided, large-scale automatic machines are being used. Four Atlas Copco drilling rigs are remotely operated from the control room on the 775 level. Later this year full scale tests of the operation and monitoring of autonomous LHDs (Tamrock Toro 2500) will be carried out. The automation network connecting the machine with the operator is based on two key technologies, a wireless high speed link for digital data, audio and video in real time and an ATM backbone network for data, audio and video transfer between the control room and the production areas.

An open pit mine can be thought of as a business unit, with capital, operating and maintenance costs that exceed those of many large business enterprises. Effective monitoring and control of truck and shovel operations requires a combination of both information systems and performance management. Production monitoring systems affect decisions at three levels: minute-by-minute decisions during the shift, procedures, and policies. The technology of production monitoring ranges from real-time data collection to manual entry of time card data into a computer. Time card information is too coarse to effectively manage a multi-million dollar fleet of mobile equipment, so higher level production monitoring systems are required. A balanced approach must be used, as uni-dimensional measures of performance such as tons produced give no indication of whether the production was achieved at the expense of another factor., An open pit mine can be thought of as a business unit, with capital, operating and maintenance costs that exceed those of many large business enterprises. Effective monitoring and control of truck and shovel operations requires a combination of both information systems and performance management. Production monitoring systems affect decisions at three levels: minute-by-minute decisions during the shift, procedures, and policies. The technology of production monitoring ranges from real-time data collection to manual entry of time card data into a computer. Time card information is too coarse to effectively manage a multi-million dollar fleet of mobile equipment, so higher level production monitoring systems are required. A balanced approach must be used, as uni-dimensional measures of performance such as tons produced give no indication of whether the production was achieved at the expense of another factor.

The global positioning system is now being used real-time in high precision, three dimensional applications on board a variety of mining machines, including dredges, blasthole drills, shovels, scrapers and dozers. Reduced survey costs are a minor portion of the gains provided. Ore control, production dozing, and reclaim examples are used to show that significant and expedient paybacks can be achieved by integrating precise position monitoring with a wireless data network and graphical office software. The information management advantages provided by the ability to easily upload current mine earthwork status via wireless network offer additional unlimited gains. Faster planning-to-excavation cycles, reduced mine to mill discrepancy, easier anticipation/visualisation of mistakes, and better record-keeping all become possible., The global positioning system is now being used real-time in high precision, three dimensional applications on board a variety of mining machines, including dredges, blasthole drills, shovels, scrapers and dozers. Reduced survey costs are a minor portion of the gains provided. Ore control, production dozing, and reclaim examples are used to show that significant and expedient paybacks can be achieved by integrating precise position monitoring with a wireless data network and graphical office software. The information management advantages provided by the ability to easily upload current mine earthwork status via wireless network offer additional unlimited gains. Faster planning-to-excavation cycles, reduced mine to mill discrepancy, easier anticipation/visualisation of mistakes, and better record-keeping all become possible.

Mount Isa Mines Ltd produces over 9 000 000 tonnes/a of ore from four large underground operations in Queensland. Three world class copper orebodies are being extracted: the 1100 orebody, the 3000 orebody, which started production in 1992, and the 3500 orebody, starting production this year. The orebodies are extracted using a unique high-rise sub-level open stoping method which allows large and productive stopes to be mined at low costs. The stope dimensions, extraction strategy, blast design and fill systems are similar for each orebody and adapted to meet geometrical constraints, rock mechanics requirements and production targets. The success of the mining method is related to good engineering practices, the application of sound rock mechanics principles and superior fill performance. Discussion is presented of the design parameters used for open stope mining at the orebodies as well as the principles and rationale that have led to this open stoping method., Mount Isa Mines Ltd produces over 9 000 000 tonnes/a of ore from four large underground operations in Queensland. Three world class copper orebodies are being extracted: the 1100 orebody, the 3000 orebody, which started production in 1992, and the 3500 orebody, starting production this year. The orebodies are extracted using a unique high-rise sub-level open stoping method which allows large and productive stopes to be mined at low costs. The stope dimensions, extraction strategy, blast design and fill systems are similar for each orebody and adapted to meet geometrical constraints, rock mechanics requirements and production targets. The success of the mining method is related to good engineering practices, the application of sound rock mechanics principles and superior fill performance. Discussion is presented of the design parameters used for open stope mining at the orebodies as well as the principles and rationale that have led to this open stoping method.

Ore from the Mount Lyell mine, Tasmania, is amenable to single stage fully autogenous grinding. Batch flotation tests carried out on pilot-scale autogenously ground ore, however, showed an unexpected recovery loss of between 1 and 3% Cu. A second pilot plant trial was set up, with the ground product feeding banks of continuous flotation cells. Single stage fully autogenous grinding (FAG), FAG/pebble and FAG/ball circuits were tested. Results confirmed a loss of about 3% recovery with single stage FAG. The FAG/ball circuit eliminated the loss. Analyses showed that autogenous milling probably produced more chalcopyrite/pyrite composites and that recovery of these composites was lower than with ball milling. In size fractions below about 53 micrometres, where chalcopyrite is well liberated, copper recovery was less affected by milling method and flotation selectivity. It was concluded that, for the Mt Lyell situation, a FAG/ball circuit was preferable to single stage FAG., Ore from the Mount Lyell mine, Tasmania, is amenable to single stage fully autogenous grinding. Batch flotation tests carried out on pilot-scale autogenously ground ore, however, showed an unexpected recovery loss of between 1 and 3% Cu. A second pilot plant trial was set up, with the ground product feeding banks of continuous flotation cells. Single stage fully autogenous grinding (FAG), FAG/pebble and FAG/ball circuits were tested. Results confirmed a loss of about 3% recovery with single stage FAG. The FAG/ball circuit eliminated the loss. Analyses showed that autogenous milling probably produced more chalcopyrite/pyrite composites and that recovery of these composites was lower than with ball milling. In size fractions below about 53 micrometres, where chalcopyrite is well liberated, copper recovery was less affected by milling method and flotation selectivity. It was concluded that, for the Mt Lyell situation, a FAG/ball circuit was preferable to single stage FAG.

Barrick Gold Corporation installed an expert-style control system on the grinding circuit at its Mercur mine in Utah. The main objective was to increase mill throughput by a minimum of 3%. The expert system team collected operating data and then created a knowledge base using Comdale/X expert system development software. The expert system moved from on-line advisory mode, testing the expert rules, to full process control in four weeks. Expert system control benefits include a 9-15% increase in mill throughput, consistent mill loading leading to less wear on SAG mill parts, and improved downstream process control., Barrick Gold Corporation installed an expert-style control system on the grinding circuit at its Mercur mine in Utah. The main objective was to increase mill throughput by a minimum of 3%. The expert system team collected operating data and then created a knowledge base using Comdale/X expert system development software. The expert system moved from on-line advisory mode, testing the expert rules, to full process control in four weeks. Expert system control benefits include a 9-15% increase in mill throughput, consistent mill loading leading to less wear on SAG mill parts, and improved downstream process control.

Prototype instrumentation, based on multispectral imaging, has been developed for ground-based remote sensing of the mineface to give high-resolution images of ore grade in real time. The area of interest is imaged at selected narrow-band wavelengths corresponding to unique features of the optical reflectance spectrum of the ore. The use of an auxiliary source of illumination gives the instrument open pit and underground capability. The raw images are converted into user-specific information, which may be a direct display of ore grade for equipment operators or input to an operations database for mine planning. The initial application of this technology is to oil sand mining. Grade trends are detailed by taking time-lapsed views as the face is mined. The concept has applicability to many industrial and metallic minerals, with the imaging wavelengths dictated by the reflectance spectrum of the specific ore., Prototype instrumentation, based on multispectral imaging, has been developed for ground-based remote sensing of the mineface to give high-resolution images of ore grade in real time. The area of interest is imaged at selected narrow-band wavelengths corresponding to unique features of the optical reflectance spectrum of the ore. The use of an auxiliary source of illumination gives the instrument open pit and underground capability. The raw images are converted into user-specific information, which may be a direct display of ore grade for equipment operators or input to an operations database for mine planning. The initial application of this technology is to oil sand mining. Grade trends are detailed by taking time-lapsed views as the face is mined. The concept has applicability to many industrial and metallic minerals, with the imaging wavelengths dictated by the reflectance spectrum of the specific ore.

Intelligent control techniques, such as fuzzy logic, have been successfully applied to the control of a semiautogenous grinding circuit at the Leeudoorn gold mine, Transvaal. Benchmarking showed that circuit performance was enhanced by the control system. Benefits included a significantly more stable circuit, improved power efficiency, a reduction in the amount of steel grinding media required, as well as more consistent throughput. A software system, Grind-ACE, was developed as an implementation platform. This approach has proved successful and flexible, allowing both intelligent and traditional control techniques to be integrated. The control system has been implemented in a unique manner with both stabilising and optimising capabilities, which has resulted in a flexible and adaptable system., Intelligent control techniques, such as fuzzy logic, have been successfully applied to the control of a semiautogenous grinding circuit at the Leeudoorn gold mine, Transvaal. Benchmarking showed that circuit performance was enhanced by the control system. Benefits included a significantly more stable circuit, improved power efficiency, a reduction in the amount of steel grinding media required, as well as more consistent throughput. A software system, Grind-ACE, was developed as an implementation platform. This approach has proved successful and flexible, allowing both intelligent and traditional control techniques to be integrated. The control system has been implemented in a unique manner with both stabilising and optimising capabilities, which has resulted in a flexible and adaptable system.

Static and kinetic tests (humidity cells) were completed at the site prior to mine development. A preliminary acid rock drainage management plan was formulated that would blend acid generating waste rock with non-acid generating waste rock. While the kinetic tests also indicated that blending (on a laboratory scale) prevented acid generation, the practicality of achieving constant blending on a mining scale needed further verification. For this, a more extensive picture of the distribution of the potentially acid generating rock at Keystone was necessary. An additional 1 585 blasthole cutting samples from the Wendy pit were analysed. This dataset was used to further develop the environmental management plan for handling the waste rock. By implementing a characterisation scheme based on total sulphur concentrations and fizz rating, waste rock could be quickly segregated without delaying the natural flow of ore from the pit., Static and kinetic tests (humidity cells) were completed at the site prior to mine development. A preliminary acid rock drainage management plan was formulated that would blend acid generating waste rock with non-acid generating waste rock. While the kinetic tests also indicated that blending (on a laboratory scale) prevented acid generation, the practicality of achieving constant blending on a mining scale needed further verification. For this, a more extensive picture of the distribution of the potentially acid generating rock at Keystone was necessary. An additional 1 585 blasthole cutting samples from the Wendy pit were analysed. This dataset was used to further develop the environmental management plan for handling the waste rock. By implementing a characterisation scheme based on total sulphur concentrations and fizz rating, waste rock could be quickly segregated without delaying the natural flow of ore from the pit.

Traditional open-pit mining methodologies and processes are being modified through the introduction and use of new technologies. The personal computer is dramatically changing the traditionally conservative mining industry by allowing mines of varying size and capacity to increase their productivity and efficiency through the application of easy-to-use office software. Computer-based monitoring and control systems are also being used more frequently to measure and optimise, in real-time, the performances of operating equipment. This capability forms the foundation of a more comprehensive management and planning facility where information acquired from the producing equipment will be used to optimise and control machine and human activities. As these technologies mature and become essential tools in a mine, they will eventually serve as the basis for more robotic and autonomous mining operations., Traditional open-pit mining methodologies and processes are being modified through the introduction and use of new technologies. The personal computer is dramatically changing the traditionally conservative mining industry by allowing mines of varying size and capacity to increase their productivity and efficiency through the application of easy-to-use office software. Computer-based monitoring and control systems are also being used more frequently to measure and optimise, in real-time, the performances of operating equipment. This capability forms the foundation of a more comprehensive management and planning facility where information acquired from the producing equipment will be used to optimise and control machine and human activities. As these technologies mature and become essential tools in a mine, they will eventually serve as the basis for more robotic and autonomous mining operations.

Rehabilitation of ecosystems degraded by surface mining is important for the sustainability of the mining industry. A study through pot experiments in the laboratory followed by a two year pilot study in the Katras and Mugma areas, Bihar, indicated that scientific screening of plant species and methodical revegetation are the two important steps of rehabilitation. Revegetation of coal mine spoil showed substantial growth of native plant species along with the colonisation of other successional species after three years. The growth performance of plants are comparable to the natural growth of vegetation on an adjacent unmined area., Rehabilitation of ecosystems degraded by surface mining is important for the sustainability of the mining industry. A study through pot experiments in the laboratory followed by a two year pilot study in the Katras and Mugma areas, Bihar, indicated that scientific screening of plant species and methodical revegetation are the two important steps of rehabilitation. Revegetation of coal mine spoil showed substantial growth of native plant species along with the colonisation of other successional species after three years. The growth performance of plants are comparable to the natural growth of vegetation on an adjacent unmined area.

Several levels of automation are discussed, beginning with the basic teleremote system, progressing to a video game system and ending with full automation. The Northparkes mine, New South Wales, has teleoperated secondary breaking rigs with an 18 m reach, 72 control functions, 18 status monitoring sensors and 4 cameras, 3 of which have remote pan, tilt, zoom, focus and lens cleaning. Discussion is presented of one successful method used to allow the simultaneous teleoperation of 12 LHDs at a distance of up to 15 km from a remote control room. Only a single fibre-optic cable is needed to carry all of the command, video, data and voice signals for the LHDs., Several levels of automation are discussed, beginning with the basic teleremote system, progressing to a video game system and ending with full automation. The Northparkes mine, New South Wales, has teleoperated secondary breaking rigs with an 18 m reach, 72 control functions, 18 status monitoring sensors and 4 cameras, 3 of which have remote pan, tilt, zoom, focus and lens cleaning. Discussion is presented of one successful method used to allow the simultaneous teleoperation of 12 LHDs at a distance of up to 15 km from a remote control room. Only a single fibre-optic cable is needed to carry all of the command, video, data and voice signals for the LHDs.

Ore pass hazards are a significant safety problem in underground metal mines in the United States. Many injuries are related to pulling or freeing ore pass chutes and structural failures of control gates and ore pass walls. Particle flow analysis methods have been used to simulate chute and control gate response to various material loading scenarios. Results from computer models indicate that dynamic impacts from ore and waste rock might be considerably greater than theory predicts. Static and dynamic loads were measured in a laboratory setting using scaled ore pass mock-ups. Field tests were initiated in an active ore pass to determine actual static and dynamic loads. Comparison of results indicates that impact and total static loads were substantially less than the computer model results suggested. Damping factors, normal and shear stiffness, and mass frictional characteristics have a significant effect on particle flow and resulting impact loads., Ore pass hazards are a significant safety problem in underground metal mines in the United States. Many injuries are related to pulling or freeing ore pass chutes and structural failures of control gates and ore pass walls. Particle flow analysis methods have been used to simulate chute and control gate response to various material loading scenarios. Results from computer models indicate that dynamic impacts from ore and waste rock might be considerably greater than theory predicts. Static and dynamic loads were measured in a laboratory setting using scaled ore pass mock-ups. Field tests were initiated in an active ore pass to determine actual static and dynamic loads. Comparison of results indicates that impact and total static loads were substantially less than the computer model results suggested. Damping factors, normal and shear stiffness, and mass frictional characteristics have a significant effect on particle flow and resulting impact loads.

One of the techniques which can be used to alleviate the problem of rockbursts is blasting the rock mass to reduce its stiffness by fracturing. This technique, called distress blasting (or preconditioning), has been used in underground mines, often with inconclusive results. An investigation has been conducted at Sigma mine, Quebec, to evaluate the effects of distress blasting in a horizontal pillar located below a backfilled stope. The pillar had been characterised and monitored to estimate the results of the blast. The field data was combined with numerical calculations using 2D and 3D models to give an indication of the distress blasting effects. Results show that this technique had some beneficial effects on the rockburst potential of the pillar., One of the techniques which can be used to alleviate the problem of rockbursts is blasting the rock mass to reduce its stiffness by fracturing. This technique, called distress blasting (or preconditioning), has been used in underground mines, often with inconclusive results. An investigation has been conducted at Sigma mine, Quebec, to evaluate the effects of distress blasting in a horizontal pillar located below a backfilled stope. The pillar had been characterised and monitored to estimate the results of the blast. The field data was combined with numerical calculations using 2D and 3D models to give an indication of the distress blasting effects. Results show that this technique had some beneficial effects on the rockburst potential of the pillar.

Microscopic investigation of a diatomite sample from El-Fayoum in Egypt showed it consisted mainly of silica diatoms of various forms, crammed in muddy carbonate matrix. Chemical analysis evaluated the sample as of low grade. Silica content assayed 79.90% with about 2.02% of iron oxide. Different beneficiation processes were carried out to minimize the content of the carbonaceous matter, fine sands and heavy oxides. Size degradation via attritioning and cyclone classification was carried out. The classified product (90% less than 5 micrometres) was subjected to wet high gradient magnetic separation as diluted pulp of 15% solids to remove magnetic coloured contaminants. Calcination and flux calcination tests were applied to improve the brightness and particle size distribution of the processed product. Size, chemical and whiteness specifications as well as other physical properties of the final product showed its suitability for fillers and filter aid applications., Microscopic investigation of a diatomite sample from El-Fayoum in Egypt showed it consisted mainly of silica diatoms of various forms, crammed in muddy carbonate matrix. Chemical analysis evaluated the sample as of low grade. Silica content assayed 79.90% with about 2.02% of iron oxide. Different beneficiation processes were carried out to minimize the content of the carbonaceous matter, fine sands and heavy oxides. Size degradation via attritioning and cyclone classification was carried out. The classified product (90% less than 5 micrometres) was subjected to wet high gradient magnetic separation as diluted pulp of 15% solids to remove magnetic coloured contaminants. Calcination and flux calcination tests were applied to improve the brightness and particle size distribution of the processed product. Size, chemical and whiteness specifications as well as other physical properties of the final product showed its suitability for fillers and filter aid applications.

Mines often cannot avoid developing sill pillars even though they cause significant difficulties when mining in burst-prone ground. Implementation of sill pillar design requires cooperation between mining, engineering and geology departments in order for a feasible plan to be executed. It is important to foresee problems related to sill pillars and their impact on mining. The mine operator will then have to impose cost-effective, practical solutions, adjust the production requirements accordingly, and construct contingency plans. Such decisions can critically affect the safety of the workings, the production cost, the ore dilution, and the anticipated recovery of the orebody. A number of case studies from Ontario are described, with emphasis on the current sill pillar practices and the possible alternatives that could be used., Mines often cannot avoid developing sill pillars even though they cause significant difficulties when mining in burst-prone ground. Implementation of sill pillar design requires cooperation between mining, engineering and geology departments in order for a feasible plan to be executed. It is important to foresee problems related to sill pillars and their impact on mining. The mine operator will then have to impose cost-effective, practical solutions, adjust the production requirements accordingly, and construct contingency plans. Such decisions can critically affect the safety of the workings, the production cost, the ore dilution, and the anticipated recovery of the orebody. A number of case studies from Ontario are described, with emphasis on the current sill pillar practices and the possible alternatives that could be used.

QIT Fer et Titane, located in Tracy near Montreal, generates 600 tonnes/d of mining and metallurgical residues that were previously rejected to the St. Lawrence River. Residues are sulphide-free, and so do not produce acid mine drainage, and are mainly composed of anorthosite rock with ilmenite ore. Physical characterisation of the residues shows a granulometric diversity combined with varying morphological characteristics. The size distribution is between 0.1 and 100 micrometres, and residues show permeability similar to clay when slightly compacted. Smaller particles of iron-titanium oxides, formed in smelters, are spherical, while anorthite and ilmenite fragments are jagged and abrasive. The physical characteristics, combined with the stability of the residues, suggest utilisation as a filling material for old pits or the closing of waste sites., QIT Fer et Titane, located in Tracy near Montreal, generates 600 tonnes/d of mining and metallurgical residues that were previously rejected to the St. Lawrence River. Residues are sulphide-free, and so do not produce acid mine drainage, and are mainly composed of anorthosite rock with ilmenite ore. Physical characterisation of the residues shows a granulometric diversity combined with varying morphological characteristics. The size distribution is between 0.1 and 100 micrometres, and residues show permeability similar to clay when slightly compacted. Smaller particles of iron-titanium oxides, formed in smelters, are spherical, while anorthite and ilmenite fragments are jagged and abrasive. The physical characteristics, combined with the stability of the residues, suggest utilisation as a filling material for old pits or the closing of waste sites.

Between 5 000 000 and 10 000 000 people are directly involved with artisanal gold and silver mining activities in Africa, Latin America and Asia. As a result of poor gold amalgamation practices in the Amazon, over 1 000 tonnes of mercury have contaminated the aquatic environments and are being taken up by fish. Symptoms of mercurialism in miners and fish-eating communities have been observed. A fuzzy logic-based expert system has been developed to assess mercury bioaccumulation risk in gold mining regions and is currently in use by a number of research organisations in Brazil, Venezuela and Surinam. The easy-to-use system can deal with imprecise data and provides an indication of the intoxication level of individuals exposed to mercury either directly or through their diet., Between 5 000 000 and 10 000 000 people are directly involved with artisanal gold and silver mining activities in Africa, Latin America and Asia. As a result of poor gold amalgamation practices in the Amazon, over 1 000 tonnes of mercury have contaminated the aquatic environments and are being taken up by fish. Symptoms of mercurialism in miners and fish-eating communities have been observed. A fuzzy logic-based expert system has been developed to assess mercury bioaccumulation risk in gold mining regions and is currently in use by a number of research organisations in Brazil, Venezuela and Surinam. The easy-to-use system can deal with imprecise data and provides an indication of the intoxication level of individuals exposed to mercury either directly or through their diet.

During the operation of a mineral processing plant, the unit processes are investigated by analysing the data extracted by means of stream sampling. The data structure is identical to the time series form. For efficient control of plant performance, it is very important to minimise sampling errors. Factors influencing these errors can be divided into two categories: material properties illustrating its heterogeneity, and sampler features. The material properties can be the sample mass, particle composition, mineral liberation, particle size distribution, or particle shape. The sampler features can be sampler geometry or velocity, or sampling geometry. Some of these variables are controllable, but the material properties cannot be controlled, leading to unavoidable sampling errors. Discussion is presented of the influence of data variation on sampling errors., During the operation of a mineral processing plant, the unit processes are investigated by analysing the data extracted by means of stream sampling. The data structure is identical to the time series form. For efficient control of plant performance, it is very important to minimise sampling errors. Factors influencing these errors can be divided into two categories: material properties illustrating its heterogeneity, and sampler features. The material properties can be the sample mass, particle composition, mineral liberation, particle size distribution, or particle shape. The sampler features can be sampler geometry or velocity, or sampling geometry. Some of these variables are controllable, but the material properties cannot be controlled, leading to unavoidable sampling errors. Discussion is presented of the influence of data variation on sampling errors.

The project is part of a general study of exploratory navigation by a vision-guided mobile robot manouevering in a large, unknown, dynamic environment such as an underground mine complex. In order to complement its path-following module, such a robot must be capable of recognising its position on a map of its environment, using landmarks. Discussion is presented of this problem through the learning and recognition of grey-scale 360 degree panoramic views representing gallery segment intersections. A multilayer neural network is proposed to make associations between these representations (as input) and identifiers corresponding to encountered intersections (as output)., The project is part of a general study of exploratory navigation by a vision-guided mobile robot manouevering in a large, unknown, dynamic environment such as an underground mine complex. In order to complement its path-following module, such a robot must be capable of recognising its position on a map of its environment, using landmarks. Discussion is presented of this problem through the learning and recognition of grey-scale 360 degree panoramic views representing gallery segment intersections. A multilayer neural network is proposed to make associations between these representations (as input) and identifiers corresponding to encountered intersections (as output).

The cut stone sector has 72 different enterprises. 25 are involved in quarrying and the other 47 in producing funerary monuments and civil engineering stone. Discussion is presented of the granite, slate, limestone and marble industries., The cut stone sector has 72 different enterprises. 25 are involved in quarrying and the other 47 in producing funerary monuments and civil engineering stone. Discussion is presented of the granite, slate, limestone and marble industries.

Strainburst (strain-type rockburst) phenomena in deep underground hard rock mines are generally characterised by a sudden release of energy in a volume of highly stressed rock. Examples of such phenomena are: crown pillar burst in overhand cut-and-fill mining, face bursts at development headings at depth, and floor bursts commonly encountered with deep shaft sinking. A simple finite element modelling approach is described which leads to the calculation of the energy release rate and the energy storage rate around mine openings. The calculations take into consideration the geomechanical properties of the rock mass and in situ stress conditions as well as the mine geometry. Such energy parameters can help identify areas of high energy release and/or accumulation due to mining activity, and hence the location and potential of strainburst. A simple criterion for the evaluation of strainburst potential is also introduced., Strainburst (strain-type rockburst) phenomena in deep underground hard rock mines are generally characterised by a sudden release of energy in a volume of highly stressed rock. Examples of such phenomena are: crown pillar burst in overhand cut-and-fill mining, face bursts at development headings at depth, and floor bursts commonly encountered with deep shaft sinking. A simple finite element modelling approach is described which leads to the calculation of the energy release rate and the energy storage rate around mine openings. The calculations take into consideration the geomechanical properties of the rock mass and in situ stress conditions as well as the mine geometry. Such energy parameters can help identify areas of high energy release and/or accumulation due to mining activity, and hence the location and potential of strainburst. A simple criterion for the evaluation of strainburst potential is also introduced.

Intelligent mine implementation is a research and development technology programme where machinery and systems for the "intelligent mine concept" are developed and tested. It is to be implemented at Outokumpu's planned Kemi underground mine, Finland, which is to start up on the site of the worked-out open pit. The programme will last three years and contains 10 development projects which have been divided into three main areas: implementation of advanced technology, data utilisation, and training and adaptation of mine personnel to the new technology, systems and environment. In addition the programme contains two supporting projects: coordination of the programme, and layout of advanced mining. The objectives of the programme are to increase the mine's productivity, decrease the total costs and improve the working conditions., Intelligent mine implementation is a research and development technology programme where machinery and systems for the "intelligent mine concept" are developed and tested. It is to be implemented at Outokumpu's planned Kemi underground mine, Finland, which is to start up on the site of the worked-out open pit. The programme will last three years and contains 10 development projects which have been divided into three main areas: implementation of advanced technology, data utilisation, and training and adaptation of mine personnel to the new technology, systems and environment. In addition the programme contains two supporting projects: coordination of the programme, and layout of advanced mining. The objectives of the programme are to increase the mine's productivity, decrease the total costs and improve the working conditions.

Highland Valley Copper, in south central British Columbia, operates one of the world's largest Cu mines. An active operational reclamation programme seeds or plants from 150 to 170 hectares annually with grasses, native trees and shrubs. By the end of 1998, approximately 28% of the 6 250 hectares disturbed by past and present mining activities will have been revegetated for one or more years. Research projects address vegetation growth and quality, soil enhancement and water quality. It is through research programmes of water purification by sulphate-reducing bacteria, wetland creation and rearing trout in a retired tailings pond that Highland Valley Copper is showing that water quality will meet reclamation objectives. Research programmes are also being carried out on the viability of grazing cattle on forage with elevated levels of Cu and Mo and the use of biosolids as a fertiliser and soil creation enhancer., Highland Valley Copper, in south central British Columbia, operates one of the world's largest Cu mines. An active operational reclamation programme seeds or plants from 150 to 170 hectares annually with grasses, native trees and shrubs. By the end of 1998, approximately 28% of the 6 250 hectares disturbed by past and present mining activities will have been revegetated for one or more years. Research projects address vegetation growth and quality, soil enhancement and water quality. It is through research programmes of water purification by sulphate-reducing bacteria, wetland creation and rearing trout in a retired tailings pond that Highland Valley Copper is showing that water quality will meet reclamation objectives. Research programmes are also being carried out on the viability of grazing cattle on forage with elevated levels of Cu and Mo and the use of biosolids as a fertiliser and soil creation enhancer.

Zambia Consolidated Copper Mines' Nchanga concentrator treats copper ores from the Nchanga open pit and underground mines. They deliver 15 500 tonnes/d and 8 000 t/d of ore to the concentrator at average head grades of 1.50% Cu and 3.00% Cu, respectively. Both ore sources have mixed sulphide/oxide mineralisation. Most of the oxide minerals report to the concentrator final tailings for further treatment at the tailings leach plant. The commissioning of the separate treatment of open pit and underground copper ores in 1995 resulted in the re-evaluation of the specific requirements for the two ores. Discussion is presented of laboratory test work results obtained from underground Cu ore samples, including the effect of grind quality on flotation recovery, optimisation of SIPX (sodium iso-propyl xanthate) collector dosage, optimisation of NaHS (sodium hydrosulphide) sulphidiser dosage, optimisation of collector and sulphidiser conditioning time, and the effect of pH on flotation recovery., Zambia Consolidated Copper Mines' Nchanga concentrator treats copper ores from the Nchanga open pit and underground mines. They deliver 15 500 tonnes/d and 8 000 t/d of ore to the concentrator at average head grades of 1.50% Cu and 3.00% Cu, respectively. Both ore sources have mixed sulphide/oxide mineralisation. Most of the oxide minerals report to the concentrator final tailings for further treatment at the tailings leach plant. The commissioning of the separate treatment of open pit and underground copper ores in 1995 resulted in the re-evaluation of the specific requirements for the two ores. Discussion is presented of laboratory test work results obtained from underground Cu ore samples, including the effect of grind quality on flotation recovery, optimisation of SIPX (sodium iso-propyl xanthate) collector dosage, optimisation of NaHS (sodium hydrosulphide) sulphidiser dosage, optimisation of collector and sulphidiser conditioning time, and the effect of pH on flotation recovery.

The Agua Rica deposit consists of complex nested porphyry intrusives and associated porphyry copper-gold mineralisation, cut by multiple igneous, hydrothermal and diatreme breccias which introduced hydrothermal mineralisation and alteration overprinting the earlier porphyry event. The mineralised system was then unroofed and underwent surficial leaching, leading to secondary copper enrichment. Drilling of more than 65 000 m in 168 holes has defined a mineral resource in excess of 1 700 000 000 tonnes of copper-gold-silver-molybdenum mineralisation. An initial feasibility study demonstrated the potential of the Agua Rica deposit to support a very large open pit mining and milling operation, producing copper and molybdenum concentrates with important amounts of gold and silver. Work is continuing to advance the project towards completion of a final feasibility study in 1999., The Agua Rica deposit consists of complex nested porphyry intrusives and associated porphyry copper-gold mineralisation, cut by multiple igneous, hydrothermal and diatreme breccias which introduced hydrothermal mineralisation and alteration overprinting the earlier porphyry event. The mineralised system was then unroofed and underwent surficial leaching, leading to secondary copper enrichment. Drilling of more than 65 000 m in 168 holes has defined a mineral resource in excess of 1 700 000 000 tonnes of copper-gold-silver-molybdenum mineralisation. An initial feasibility study demonstrated the potential of the Agua Rica deposit to support a very large open pit mining and milling operation, producing copper and molybdenum concentrates with important amounts of gold and silver. Work is continuing to advance the project towards completion of a final feasibility study in 1999.

One of the major problems associated with the use of fully grouted cable bolts is the lack of a reliable method to monitor the tension that develops in response to rock mass displacements. In the past, measurement gauges were mounted external to the cable itself which gave potential interference with the bond strength in the measurement area. Discussion is presented of field data from a novel instrumented cable bolt. The technology is applicable to conventional and modified geometry cables as well as twin strand cable bolts. As the device is internal to the cable, it does not interfere with the bond strength. Results from two initial underground trials, at Bousquet, Quebec, and Callinan, Manitoba, are presented., One of the major problems associated with the use of fully grouted cable bolts is the lack of a reliable method to monitor the tension that develops in response to rock mass displacements. In the past, measurement gauges were mounted external to the cable itself which gave potential interference with the bond strength in the measurement area. Discussion is presented of field data from a novel instrumented cable bolt. The technology is applicable to conventional and modified geometry cables as well as twin strand cable bolts. As the device is internal to the cable, it does not interfere with the bond strength. Results from two initial underground trials, at Bousquet, Quebec, and Callinan, Manitoba, are presented.

Mont Porphyre is a large (over 200 000 000 tonnes) low grade (less than 1% Cu) porphyry copper deposit which has been defined by surface diamond drilling below Mont Porphyre near Murdochville, Quebec. The deposit is situated between 1 000 and 1 700 m below surface and was the recent focus of a scope study by Noranda Mining and Exploration Inc. A geomechanical investigation was conducted, with particular emphasis on the methodology applied to geomechanical data collection and analysis. Underground access was not available at Mont Porphyre so geomechanical data was collected primarily from surface diamond drilling and a review of similar mining areas at Mines Gaspe. Procedures developed for core logging and core orientation in order to gather geomechanical data are discussed., Mont Porphyre is a large (over 200 000 000 tonnes) low grade (less than 1% Cu) porphyry copper deposit which has been defined by surface diamond drilling below Mont Porphyre near Murdochville, Quebec. The deposit is situated between 1 000 and 1 700 m below surface and was the recent focus of a scope study by Noranda Mining and Exploration Inc. A geomechanical investigation was conducted, with particular emphasis on the methodology applied to geomechanical data collection and analysis. Underground access was not available at Mont Porphyre so geomechanical data was collected primarily from surface diamond drilling and a review of similar mining areas at Mines Gaspe. Procedures developed for core logging and core orientation in order to gather geomechanical data are discussed.

Discussion is presented of pilot production tests carried out at Brunswick Mining 1 000 level with an autoguided truck. The objective was to evaluate the possibility of using the STAS SIAM autoguidance system in a day-to-day operation. A 26 ton truck, equipped with the autoguidance system, was loaded and the ore trammed over a distance of 500 m and dumped into an ore pass. Along with the autoguidance system, a real time communication system was installed to supervise the automated truck. Also, to assure personnel safety, an active personnel detection system was developed. Traffic control algorithms were implemented on a PLC to manage interactions between truck and scoop. The PLC and the communication network were also used to manage vent doors and gates in the automated zones., Discussion is presented of pilot production tests carried out at Brunswick Mining 1 000 level with an autoguided truck. The objective was to evaluate the possibility of using the STAS SIAM autoguidance system in a day-to-day operation. A 26 ton truck, equipped with the autoguidance system, was loaded and the ore trammed over a distance of 500 m and dumped into an ore pass. Along with the autoguidance system, a real time communication system was installed to supervise the automated truck. Also, to assure personnel safety, an active personnel detection system was developed. Traffic control algorithms were implemented on a PLC to manage interactions between truck and scoop. The PLC and the communication network were also used to manage vent doors and gates in the automated zones.

Traditional methods of valuation often fail to assign the proper value or timing to management decisions such as development, production levels, cutoff grades and capital expansion. Hence they do not address the critical questions of when, at what spot price, and how much ore to extract. The theory of option pricing can produce a valuation that resolves these issues. Discussion is presented of realistic cashflow models that explicitly incorporate management's ability to affect cashflows through strategic decisions in the presence of operating constraints and market price fluctuations. Option pricing techniques are used to value the project and find the best operating policy. The policy is dynamic and reflects the changing economic environment., Traditional methods of valuation often fail to assign the proper value or timing to management decisions such as development, production levels, cutoff grades and capital expansion. Hence they do not address the critical questions of when, at what spot price, and how much ore to extract. The theory of option pricing can produce a valuation that resolves these issues. Discussion is presented of realistic cashflow models that explicitly incorporate management's ability to affect cashflows through strategic decisions in the presence of operating constraints and market price fluctuations. Option pricing techniques are used to value the project and find the best operating policy. The policy is dynamic and reflects the changing economic environment.

Flexibility represents the ability to adapt to internal or external change in operating conditions in order to sustain economic, environmental or social performance. Changes experienced in ground conditions may necessitate adjusting the timing, rate or location of mining in order to continue to operate profitably and safely. At the corporate level, the ability to close high cost mines, replacing the lost production from lower cost mines, is another form of flexibility. Discussion is presented of the nature of flexibility through a series of examples at the stope, ore zone, mine and divisional levels. Discounted cash flow analysis and option pricing are considered as potential ways to value flexibility. Consideration is given to concurrent engineering, simulation and valuation techniques to reduce operational and design constraints and to allow the integration of flexibility more formally and routinely into mine planning and design., Flexibility represents the ability to adapt to internal or external change in operating conditions in order to sustain economic, environmental or social performance. Changes experienced in ground conditions may necessitate adjusting the timing, rate or location of mining in order to continue to operate profitably and safely. At the corporate level, the ability to close high cost mines, replacing the lost production from lower cost mines, is another form of flexibility. Discussion is presented of the nature of flexibility through a series of examples at the stope, ore zone, mine and divisional levels. Discounted cash flow analysis and option pricing are considered as potential ways to value flexibility. Consideration is given to concurrent engineering, simulation and valuation techniques to reduce operational and design constraints and to allow the integration of flexibility more formally and routinely into mine planning and design.

The Iron Ore Company of Canada (IOC) supplies superior products to the world's steel industries. Advanced technologies and best practices are integrated with sound business basics to ensure long term success. In 1997, IOC established a Maintenance Strategy Task Force (MSTF) to develop and implement a fully integrated maintenance management strategy. This task force provides leadership in the integration of new technologies and advanced management philosophies in the development of the maintenance strategy. To be effective in the long term, the maintenance strategy must be intimately linked to IOC's business success as the strategy plays a vital role in asset management, cost reduction and ultimately profitability. Discussion is presented of the work of the task force with particular emphasis on its interaction with day-to-day process managers and its support of their commitment to meet customer requirements., The Iron Ore Company of Canada (IOC) supplies superior products to the world's steel industries. Advanced technologies and best practices are integrated with sound business basics to ensure long term success. In 1997, IOC established a Maintenance Strategy Task Force (MSTF) to develop and implement a fully integrated maintenance management strategy. This task force provides leadership in the integration of new technologies and advanced management philosophies in the development of the maintenance strategy. To be effective in the long term, the maintenance strategy must be intimately linked to IOC's business success as the strategy plays a vital role in asset management, cost reduction and ultimately profitability. Discussion is presented of the work of the task force with particular emphasis on its interaction with day-to-day process managers and its support of their commitment to meet customer requirements.

The Canadian uranium industry began in the 1930s with the development of the Port Radium pitchblende deposit along the east shore of Great Bear Lake in the Northwest Territories. The only other confirmed pithchblende occurrences were reported from the north shore of Lake Athabasca, and this part of northern Saskatchewan became the main exploration focus. In late 1947, the ban on private prospecting and staking for uranium was lifted resulting in hundreds of radioactive occurrences being found throughout the Beaverlodge area. A total of 36 deposits were explored and 16 individual deposits achieved some production by the late 1950s. The last producing mine, Eldorado's Beaverlodge operation, ceased operations in mid-1982. Between 1953 and 1983, the cumulative production from the Beaverlodge mining district was 64 800 000 lb U3O8. Geology and mineralogy of the area is discussed along with descriptions of the Ace-Fay-Verna and Gunnar mines., The Canadian uranium industry began in the 1930s with the development of the Port Radium pitchblende deposit along the east shore of Great Bear Lake in the Northwest Territories. The only other confirmed pithchblende occurrences were reported from the north shore of Lake Athabasca, and this part of northern Saskatchewan became the main exploration focus. In late 1947, the ban on private prospecting and staking for uranium was lifted resulting in hundreds of radioactive occurrences being found throughout the Beaverlodge area. A total of 36 deposits were explored and 16 individual deposits achieved some production by the late 1950s. The last producing mine, Eldorado's Beaverlodge operation, ceased operations in mid-1982. Between 1953 and 1983, the cumulative production from the Beaverlodge mining district was 64 800 000 lb U3O8. Geology and mineralogy of the area is discussed along with descriptions of the Ace-Fay-Verna and Gunnar mines.

The Labrador Trough contains world class iron deposits which have been mined since 1954. Concentrate production began in 1961 in the southwest end of the Trough, with three mines currently producing concentrate and pellets at a rate of 35 000 000 tonnes per year. Ore has been outlined to the west and north of Schefferville, to the west of Ungava Bay and in the area from Wabush Lake to Mont Wright. In this area, three mining operations are present with reserves and resources in the order of 5 000 000 000 tonnes. Several facies of iron formation within the Sokoman Formation reflect variations in chemical composition and depositional conditions. This band extends for about 1 200 km southeast of Ungava Bay through both Quebec and Labrador. The iron formation is essentially highly folded and faulted along most of its length with a variable degree of metamorphism, ranging from intense to greenschist facies. The stratigraphy, structure and mineralogy of the producing mines is described along with the history of discoveries., The Labrador Trough contains world class iron deposits which have been mined since 1954. Concentrate production began in 1961 in the southwest end of the Trough, with three mines currently producing concentrate and pellets at a rate of 35 000 000 tonnes per year. Ore has been outlined to the west and north of Schefferville, to the west of Ungava Bay and in the area from Wabush Lake to Mont Wright. In this area, three mining operations are present with reserves and resources in the order of 5 000 000 000 tonnes. Several facies of iron formation within the Sokoman Formation reflect variations in chemical composition and depositional conditions. This band extends for about 1 200 km southeast of Ungava Bay through both Quebec and Labrador. The iron formation is essentially highly folded and faulted along most of its length with a variable degree of metamorphism, ranging from intense to greenschist facies. The stratigraphy, structure and mineralogy of the producing mines is described along with the history of discoveries.

The central control station for the Welzow South coal mine is designed in such a way as to allow supervision, operation and control of the whole open cast mine including the storage area and the train loading facilities. Servers are designed as interfaces for the working computer stations or other network users. The process data collected are given to this network by means of the TCP/IP protocol. The central control station personnel receive information taken from the production process via the process data acquisition, communication data and video communication networks., The central control station for the Welzow South coal mine is designed in such a way as to allow supervision, operation and control of the whole open cast mine including the storage area and the train loading facilities. Servers are designed as interfaces for the working computer stations or other network users. The process data collected are given to this network by means of the TCP/IP protocol. The central control station personnel receive information taken from the production process via the process data acquisition, communication data and video communication networks.

Blast vibration monitoring, instrumentation, and numerical modelling were employed for preliminary back-analysis of primary and secondary open stope hanging-wall behaviour within a highly stressed, foliated rock mass at No. 2 mine of the Bousquet complex, Quebec. Blast vibration was monitored using triaxial geophones and a Blastronics BMX system. Hanging-wall behaviour was assessed on the basis of data obtained from grouted extensometers and a cavity monitoring system. FLAC numerical modelling back-analysis was carried out to examine hanging-wall stress and displacement distributions. A comparison of the final stope profile against projected near-field blast vibration and modelled stope conditions provided an indication of the mechanisms influencing hanging wall stability., Blast vibration monitoring, instrumentation, and numerical modelling were employed for preliminary back-analysis of primary and secondary open stope hanging-wall behaviour within a highly stressed, foliated rock mass at No. 2 mine of the Bousquet complex, Quebec. Blast vibration was monitored using triaxial geophones and a Blastronics BMX system. Hanging-wall behaviour was assessed on the basis of data obtained from grouted extensometers and a cavity monitoring system. FLAC numerical modelling back-analysis was carried out to examine hanging-wall stress and displacement distributions. A comparison of the final stope profile against projected near-field blast vibration and modelled stope conditions provided an indication of the mechanisms influencing hanging wall stability.

Geared specifically to the needs of hard rock miners, an interactive multimedia learning tool has been developed which employs sound, text, photos, animation and video in a dynamic and multi-sensorial approach to training on rock bolting. Prepared specifically for workers in the Quebec mining industry, it focuses on the modes of support of rock bolts, technical data and installation methodology. Many practical recommendations are included in the system., Geared specifically to the needs of hard rock miners, an interactive multimedia learning tool has been developed which employs sound, text, photos, animation and video in a dynamic and multi-sensorial approach to training on rock bolting. Prepared specifically for workers in the Quebec mining industry, it focuses on the modes of support of rock bolts, technical data and installation methodology. Many practical recommendations are included in the system.

A paste fill blast damage study was carried out at Louvicourt, Quebec, in June 1997 on the 860 m level. Instrumentation included vibration monitors (using 6 sets of triaxial geophones grouted in the pastefill), a borehole camera to observe the damage and a cavity monitoring system for three-dimensional surveys of the blasted stope. The test stope was mined out by four slot blasts and three mass blasts. Most of the damage was created by the mass blasts. It was discovered that the accumulation of ground vibration was mainly due to the low seismic velocities in the pastefill and the relatively tight delay between blastholes. In addition, there was a substantial difference between the critical peak particle velocities in the confined and unconfined pastefill. Modifications to the mining sequence of secondary stopes and blast design are currently being investigated for the near future with the objective of reducing pastefill sloughage., A paste fill blast damage study was carried out at Louvicourt, Quebec, in June 1997 on the 860 m level. Instrumentation included vibration monitors (using 6 sets of triaxial geophones grouted in the pastefill), a borehole camera to observe the damage and a cavity monitoring system for three-dimensional surveys of the blasted stope. The test stope was mined out by four slot blasts and three mass blasts. Most of the damage was created by the mass blasts. It was discovered that the accumulation of ground vibration was mainly due to the low seismic velocities in the pastefill and the relatively tight delay between blastholes. In addition, there was a substantial difference between the critical peak particle velocities in the confined and unconfined pastefill. Modifications to the mining sequence of secondary stopes and blast design are currently being investigated for the near future with the objective of reducing pastefill sloughage.

Finely ground waste glass can be utilized as an effective partial pozzolanic replacement for normal Portland cement in various types of mine backfill at potential cost savings of up to 50%. The comparative strength behaviour is summarised of a variety of mine backfill products, from different mine sites, when manufactured in the forms of hydraulic slurry and paste backfill media. For slurry and paste backfill mixtures, up to 35% of the Portland cement binder was replaced by ground waste glass material with excellent strength characteristics being developed. Ground waste glass gave equivalent or better backfill strength characteristics than Portland cement in the long term over cure intervals up to 224 days. Results are presented of parametric studies to explore the sensitivity of ground waste glass pozzolans to variations in mixture moisture content, tailings mineralogy, pozzolan size distribution, cure temperature and glass type., Finely ground waste glass can be utilized as an effective partial pozzolanic replacement for normal Portland cement in various types of mine backfill at potential cost savings of up to 50%. The comparative strength behaviour is summarised of a variety of mine backfill products, from different mine sites, when manufactured in the forms of hydraulic slurry and paste backfill media. For slurry and paste backfill mixtures, up to 35% of the Portland cement binder was replaced by ground waste glass material with excellent strength characteristics being developed. Ground waste glass gave equivalent or better backfill strength characteristics than Portland cement in the long term over cure intervals up to 224 days. Results are presented of parametric studies to explore the sensitivity of ground waste glass pozzolans to variations in mixture moisture content, tailings mineralogy, pozzolan size distribution, cure temperature and glass type.