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The SmartTag ore tracking system was installed at the Kittila underground open stoping gold mine, Finland, in 2013. This system allows spatial ore characteristic data of a parcel of ore to be linked with time-based plant performance data such as particle size distribution, specific energy, and throughput. The orebody at Kittila is complex, and ore type can vary between each loader bucket which makes reconciliation and scheduling difficult. Environmental conditions can be extreme, with temperatures down to -20 degrees C. SmartTags in run-of-mine ore allow for monitoring of ore from underground loader through to the processing plant. When a tag is detected at the plant, the characteristics of its associated ore are compared to those expected in the plant, and changes can be made to processing options if necessary. When troublesome ore types are identified, plant feed with similar properties can be flagged as having the potential to disrupt plant throughput or recovery, and remedial action taken. Tags and analysis results are used daily at Kittila to evaluate and adjust mill feed based on gold and sulphur grades. Monthly results are used to reconcile the amount of mill feed from each stope, which can then be converted into a monetary value., The SmartTag ore tracking system was installed at the Kittila underground open stoping gold mine, Finland, in 2013. This system allows spatial ore characteristic data of a parcel of ore to be linked with time-based plant performance data such as particle size distribution, specific energy, and throughput. The orebody at Kittila is complex, and ore type can vary between each loader bucket which makes reconciliation and scheduling difficult. Environmental conditions can be extreme, with temperatures down to -20 degrees C. SmartTags in run-of-mine ore allow for monitoring of ore from underground loader through to the processing plant. When a tag is detected at the plant, the characteristics of its associated ore are compared to those expected in the plant, and changes can be made to processing options if necessary. When troublesome ore types are identified, plant feed with similar properties can be flagged as having the potential to disrupt plant throughput or recovery, and remedial action taken. Tags and analysis results are used daily at Kittila to evaluate and adjust mill feed based on gold and sulphur grades. Monthly results are used to reconcile the amount of mill feed from each stope, which can then be converted into a monetary value.

A Metso SmartEar was installed at the Pueblo Viejo Au operation in the Dominican Republic to monitor the acoustic emissions of the semiautogenous grinding mill and to optimise mill control. One output from the system is the impact counter, which measures steel-on-steel impacts on the mill shell and uses both frequency and time domain analysis to approximate the number of ball impacts per minute. Tuning of the filters and impact counter was carried out and the final set points were filter 1 between 1 000 and 3 000 Hz, filter 2 between 100 and 1 000 Hz and impact counter frequency range between 1 000 and 3 000 Hz. The effectiveness of the system was validated by analysing a data set and correlating the relationship between grinding efficiency in terms of specific energy and sound levels from the system. The results indicated that a moderate impact count or sound level will on average produce more efficient grinding than low or high impact counts or sound levels. Contrary to expectation, the relationship between speed and impact was not direct. The relationship showed that the feeds are higher when the impacts are in the middle bands, and lower impacts corresponded with higher power. Overall, a medium level of impacts results in more efficient grinding., A Metso SmartEar was installed at the Pueblo Viejo Au operation in the Dominican Republic to monitor the acoustic emissions of the semiautogenous grinding mill and to optimise mill control. One output from the system is the impact counter, which measures steel-on-steel impacts on the mill shell and uses both frequency and time domain analysis to approximate the number of ball impacts per minute. Tuning of the filters and impact counter was carried out and the final set points were filter 1 between 1 000 and 3 000 Hz, filter 2 between 100 and 1 000 Hz and impact counter frequency range between 1 000 and 3 000 Hz. The effectiveness of the system was validated by analysing a data set and correlating the relationship between grinding efficiency in terms of specific energy and sound levels from the system. The results indicated that a moderate impact count or sound level will on average produce more efficient grinding than low or high impact counts or sound levels. Contrary to expectation, the relationship between speed and impact was not direct. The relationship showed that the feeds are higher when the impacts are in the middle bands, and lower impacts corresponded with higher power. Overall, a medium level of impacts results in more efficient grinding.

The Phu Kam Cu-Au deposit in Laos is an extremely heterogeneous orebody with complex and variable mineralogical, geological and geotechnical properties which affect plant throughput and metallurgical performance. An increased proportion of highly competent ores is expected from future operations which has the potential to limit plant throughput. A throughput forecasting and optimisation project was conducted to evaluate how current throughput rates could be maintained over the life of mine. The project involved a review of current blasting, crushing and grinding processes and the development of a throughput prediction model based on geometallurgical modelling. The identification of opportunities for increasing throughout and improving overall comminution circuit performance when treating the most competent ore types was also included. A shorter term objective was to determine if and when secondary crushing or other process changes would be required in the shorter term. The throughput prediction model consists of integrated, site-specific models for drill and blasting, crushing and milling which were developed, calibrated and validated using SmartTag ore tracking technology, which links ore source and properties with blasting and plant performance in real time. A GeoMetso system is also being implemented which uses SmartTag to continuously collect plant data and automatically update the predictive models and block model in real time, eliminating the need for ore characterisation tests and improving the accuracy and predictive ability of the geometallurgical model., The Phu Kam Cu-Au deposit in Laos is an extremely heterogeneous orebody with complex and variable mineralogical, geological and geotechnical properties which affect plant throughput and metallurgical performance. An increased proportion of highly competent ores is expected from future operations which has the potential to limit plant throughput. A throughput forecasting and optimisation project was conducted to evaluate how current throughput rates could be maintained over the life of mine. The project involved a review of current blasting, crushing and grinding processes and the development of a throughput prediction model based on geometallurgical modelling. The identification of opportunities for increasing throughout and improving overall comminution circuit performance when treating the most competent ore types was also included. A shorter term objective was to determine if and when secondary crushing or other process changes would be required in the shorter term. The throughput prediction model consists of integrated, site-specific models for drill and blasting, crushing and milling which were developed, calibrated and validated using SmartTag ore tracking technology, which links ore source and properties with blasting and plant performance in real time. A GeoMetso system is also being implemented which uses SmartTag to continuously collect plant data and automatically update the predictive models and block model in real time, eliminating the need for ore characterisation tests and improving the accuracy and predictive ability of the geometallurgical model.

Soil C sequestration through changes in land use and management is one of the sustainable and long-term strategies to mitigate climate change. This research explores and quantifies the role of soil and land use as determinants of the ability of soils to store C along Mediterranean systems. Detailed studies of soil organic C (SOC) dynamics are necessary in order to identify factors determining fluctuations and intensity of changes. In this study, SOC contents from different soil and land use types have been investigated in Andalusia (Southern Spain). We have used soil information from different databases, as well as land use digital maps, climate databases and digital elevation models. The average SOC content for each soil control section (0-25, 25-50 and 50-75 cm) was determined and SOC stocks were calculated for each combination of soil and land use type, using soil and land cover maps. The total organic C stocks in soils of Andalusia is 415 Tg for the upper 75cm, with average values ranging from 15.9 Mg C ha-1 (Solonchaks under "arable land") to 107.6 Mg Cha-1 (Fluvisols from "wetlands"). Up to 55 % of SOC accumulates in the top 25 cm of soil (229.7 Tg). This research constitutes a preliminary assessment for modelling SOC stock under scenarios of land use and climate change. © Author(s) 2012. CC Attribution 3.0 License.

Blast-induced orebody movement can be measured using visual markers or remote markers such as magnetic or RFID, but it is difficult to model movement with a purely theoretical approach. Rock mass structure, blast energy, design and timing contours all have significant and interrelated effects on blast movement vectors. There have been significant advances in blast movement modelling capability, but unpredictable blast movement limits their use in the context of production ore control. Without physical field measurements, accurate predictions of movement are almost impossible. Limitations of traditional surface markers in determining three-dimensional (3D) blast movement within the orebody are reviewed, and advancements in accurately measuring these vectors within blasted ore discussed., Blast-induced orebody movement can be measured using visual markers or remote markers such as magnetic or RFID, but it is difficult to model movement with a purely theoretical approach. Rock mass structure, blast energy, design and timing contours all have significant and interrelated effects on blast movement vectors. There have been significant advances in blast movement modelling capability, but unpredictable blast movement limits their use in the context of production ore control. Without physical field measurements, accurate predictions of movement are almost impossible. Limitations of traditional surface markers in determining three-dimensional (3D) blast movement within the orebody are reviewed, and advancements in accurately measuring these vectors within blasted ore discussed.

Two systems are described that have been developed by Metso Minerals Process Technology for measuring mill load, the SmartEar acoustic system and an online model-based charge estimation system. SmartEar analyses an audio signal from the mill, allowing each different frequency component to be viewed, analysed and used in process control for load estimation. By isolating different frequencies, SmartEar can provide an estimate of mill load. The online dynamic mill model uses measurable mill parameters such as power to predict the current total load. Kalman filtering can also be used to further increase the accuracy of the model. Both systems have been installed at the Cannington Pb-Zn-Ag mine in Queensland, Australia, to measure the load within the autogenous grinding mill. The load estimations were compared with the bearing pressure reading, which is the current method used to control mill load. The redundant estimates of mill load provide increased confidence and more robust grinding operation under a wide range of conditions., Two systems are described that have been developed by Metso Minerals Process Technology for measuring mill load, the SmartEar acoustic system and an online model-based charge estimation system. SmartEar analyses an audio signal from the mill, allowing each different frequency component to be viewed, analysed and used in process control for load estimation. By isolating different frequencies, SmartEar can provide an estimate of mill load. The online dynamic mill model uses measurable mill parameters such as power to predict the current total load. Kalman filtering can also be used to further increase the accuracy of the model. Both systems have been installed at the Cannington Pb-Zn-Ag mine in Queensland, Australia, to measure the load within the autogenous grinding mill. The load estimations were compared with the bearing pressure reading, which is the current method used to control mill load. The redundant estimates of mill load provide increased confidence and more robust grinding operation under a wide range of conditions.

A description is given of the process integration and optimisation methodology developed by Metso Minerals Process Technology for optimising blasting and comminution processes in relation to fragmentation. The method involves a number of steps including benchmarking, rock characterisation, measurements, modelling/simulation of blasting and comminution processes and, where required, material tracking. The measurements collected at site are combined with rock characterisation and definition of ore domains to model the complete process chain. The data are used to develop site-specific models of blast fragmentation, crushing, grinding and flotation, allowing customised blast patterns to be developed to optimise crushing and grinding performance. Process constraints such as wall stability, ore dilution, muck pile characteristics, size of mining equipment, size and installed power of crushing and milling equipment and other process bottlenecks are considered. Case studies presented include investigation of relationship between powder factor and SAG mill throughput at a Cu mine, fragmentation measurement and modelling at a number of mine sites and the use of rock characterisation and blast domain definition to improve throughput forecasting., A description is given of the process integration and optimisation methodology developed by Metso Minerals Process Technology for optimising blasting and comminution processes in relation to fragmentation. The method involves a number of steps including benchmarking, rock characterisation, measurements, modelling/simulation of blasting and comminution processes and, where required, material tracking. The measurements collected at site are combined with rock characterisation and definition of ore domains to model the complete process chain. The data are used to develop site-specific models of blast fragmentation, crushing, grinding and flotation, allowing customised blast patterns to be developed to optimise crushing and grinding performance. Process constraints such as wall stability, ore dilution, muck pile characteristics, size of mining equipment, size and installed power of crushing and milling equipment and other process bottlenecks are considered. Case studies presented include investigation of relationship between powder factor and SAG mill throughput at a Cu mine, fragmentation measurement and modelling at a number of mine sites and the use of rock characterisation and blast domain definition to improve throughput forecasting.

The installation is described of an OCS expert system and three VisioRock online particle size analysis cameras to optimise the performance of the grinding circuit at the Cannington, Queensland, Ag-Pb operation. The main purpose of the system, which incorporates a dynamic SAG/AG mill model, was to stabilise grind size and feed to the flotation circuit. Online vision-based particle size measurements of the AG mill feed and recycle crusher product are integrated into the logic of the control algorithm. Significant stable throughput increases have been achieved, AG mill overload events have been reduced and pebble crusher utilisation has also increased., The installation is described of an OCS expert system and three VisioRock online particle size analysis cameras to optimise the performance of the grinding circuit at the Cannington, Queensland, Ag-Pb operation. The main purpose of the system, which incorporates a dynamic SAG/AG mill model, was to stabilise grind size and feed to the flotation circuit. Online vision-based particle size measurements of the AG mill feed and recycle crusher product are integrated into the logic of the control algorithm. Significant stable throughput increases have been achieved, AG mill overload events have been reduced and pebble crusher utilisation has also increased.

A description is given of the process integration and optimisation (PIO) method which has been developed by Metso Minerals Process Technology Asia-Pacific to improve the efficiency of the mine/mill interface. The methodology involves benchmarking, rock characterisation, measurements, modelling/simulation and, where required, material tracking. The rock characterisation step defines blasting domains and allows different blasting and crushing strategies to be developed. A list of operational and control changes are developed for both the mine and the concentrator. Simulation tools can also be used to compare current with recommended practices, so that when material properties vary over time the benefits can still be quantified. The success of a PIO project relies on the ability of an organisation to implement change, both operationally and culturally., A description is given of the process integration and optimisation (PIO) method which has been developed by Metso Minerals Process Technology Asia-Pacific to improve the efficiency of the mine/mill interface. The methodology involves benchmarking, rock characterisation, measurements, modelling/simulation and, where required, material tracking. The rock characterisation step defines blasting domains and allows different blasting and crushing strategies to be developed. A list of operational and control changes are developed for both the mine and the concentrator. Simulation tools can also be used to compare current with recommended practices, so that when material properties vary over time the benefits can still be quantified. The success of a PIO project relies on the ability of an organisation to implement change, both operationally and culturally.

Froth images were collected from various cells operated at different air rates and froth depths in the Northparkes, New South Wales, Cu roughing and scavenging circuit. Samples were also collected to determine the cell performance under each operating condition. The froth images were processed using the Visiofroth system and froth velocity, bubble size, froth collapse rate and froth colour parameters calculated. The parameters were compared to the measured concentrate flow and concentrate grade produced under each condition. The results showed that the grade of attached particles on the surface of the froth was linearly correlated with the bubble collapse rate. Overall concentrate grade was best predicted using an equation incorporating the collapse rate and velocity parameters. The concentrate tonnage flow is strongly correlated with froth velocity whereas the concentrate grade is best correlated using froth velocity in combination with a bubble stability parameter which affects the bubble size distribution on the top surface of the froth. The velocity measured by Visiofroth can be used to increase or decrease recovery to achieve a particular processing target, and may potentially be used in a process control optimisation strategy., Froth images were collected from various cells operated at different air rates and froth depths in the Northparkes, New South Wales, Cu roughing and scavenging circuit. Samples were also collected to determine the cell performance under each operating condition. The froth images were processed using the Visiofroth system and froth velocity, bubble size, froth collapse rate and froth colour parameters calculated. The parameters were compared to the measured concentrate flow and concentrate grade produced under each condition. The results showed that the grade of attached particles on the surface of the froth was linearly correlated with the bubble collapse rate. Overall concentrate grade was best predicted using an equation incorporating the collapse rate and velocity parameters. The concentrate tonnage flow is strongly correlated with froth velocity whereas the concentrate grade is best correlated using froth velocity in combination with a bubble stability parameter which affects the bubble size distribution on the top surface of the froth. The velocity measured by Visiofroth can be used to increase or decrease recovery to achieve a particular processing target, and may potentially be used in a process control optimisation strategy.

Metso Minerals Process Technology Asia-Pacific and South America (MMPT) have been working with operations around the world to increase their efficiency through Mine-to-Mill or Process Integration and Optimisation (PIO) projects. These projects have delivered significant improvements in mine efficiency, mill throughput and reduced operating costs at mines around the world. The MMPT methodology involves rock characterisation, site auditing, data collection, modelling/simulation and implementation of integrated operating and control strategies on site. After a site visit to collect data on geology, mining and processing, a typical PIO project builds a site-specific model of the various stages of the mine's operations. This proven methodology has applications ranging from greenfield projects to long-standing operations. The paper discusses a recent application of PIO conducted at a large open-pit operation in South America and emphasises that all operations have the potential to use their current equipment more efficiently., Metso Minerals Process Technology Asia-Pacific and South America (MMPT) have been working with operations around the world to increase their efficiency through Mine-to-Mill or Process Integration and Optimisation (PIO) projects. These projects have delivered significant improvements in mine efficiency, mill throughput and reduced operating costs at mines around the world. The MMPT methodology involves rock characterisation, site auditing, data collection, modelling/simulation and implementation of integrated operating and control strategies on site. After a site visit to collect data on geology, mining and processing, a typical PIO project builds a site-specific model of the various stages of the mine's operations. This proven methodology has applications ranging from greenfield projects to long-standing operations. The paper discusses a recent application of PIO conducted at a large open-pit operation in South America and emphasises that all operations have the potential to use their current equipment more efficiently.

A description is given of a constraint-based expert control system which has been implemented on the high-grade crushing and screening plant at Mount Tom Price, Western Australia, along with VisioRock, a vision- based oversize detection system operating on six product conveyor belts. The expert system control has resulted in increased production by maximising dynamic constraint utilisation. The latter is a concept developed for effectively evaluating constraint-based control logic performance. Details are given of the hardware and software used and the operational results., A description is given of a constraint-based expert control system which has been implemented on the high-grade crushing and screening plant at Mount Tom Price, Western Australia, along with VisioRock, a vision- based oversize detection system operating on six product conveyor belts. The expert system control has resulted in increased production by maximising dynamic constraint utilisation. The latter is a concept developed for effectively evaluating constraint-based control logic performance. Details are given of the hardware and software used and the operational results.

An ore characterisation and mine-to-mill throughput modelling approach at the 120 000 t/d Cu-Au plant in Indonesia has significantly improved prediction of mill throughput rates. Ore domains defined from ore lithology, rock structure designation and rock strength index are used in blasting, crushing and grinding models to provide accurate throughput predictions for mediium- to long-term production forecasting, although short-term predictions are indluenced by external factors such as segregation, surge-pile residence and blending. Benefits have included greatly improved mine-mill communication and optimum blast fragment generation and prediction., An ore characterisation and mine-to-mill throughput modelling approach at the 120 000 t/d Cu-Au plant in Indonesia has significantly improved prediction of mill throughput rates. Ore domains defined from ore lithology, rock structure designation and rock strength index are used in blasting, crushing and grinding models to provide accurate throughput predictions for mediium- to long-term production forecasting, although short-term predictions are indluenced by external factors such as segregation, surge-pile residence and blending. Benefits have included greatly improved mine-mill communication and optimum blast fragment generation and prediction.

A joint venture between the Porgera joint venture and Dyno Noble aimed at increasing throughput at the semi-autogenous (SAG) mills at the Porgera gold mine, in Papua New Guinea, through optimisation of the blast fragmentation. Test blasts showed that high-energy blasts could increase mill throughput by up to 15%. However changes in ore geology, potential ore dilution/loss and possible wall damage raised doubts about the economic benefits of using these blasts throughout the ore body. Dyno Noble's consulting arm, DynoConsult, and the Julius Kruttschnitt Mineral Research Centre (JKMRC) jointly developed a blast management system for tracking the quality of the blasts and the benefits in downstream processing. The implementation of the scheme is discussed, together with its results to date., A joint venture between the Porgera joint venture and Dyno Noble aimed at increasing throughput at the semi-autogenous (SAG) mills at the Porgera gold mine, in Papua New Guinea, through optimisation of the blast fragmentation. Test blasts showed that high-energy blasts could increase mill throughput by up to 15%. However changes in ore geology, potential ore dilution/loss and possible wall damage raised doubts about the economic benefits of using these blasts throughout the ore body. Dyno Noble's consulting arm, DynoConsult, and the Julius Kruttschnitt Mineral Research Centre (JKMRC) jointly developed a blast management system for tracking the quality of the blasts and the benefits in downstream processing. The implementation of the scheme is discussed, together with its results to date.