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The United States Department of Energy has initiated numerous activities to identify strategies t... more The United States Department of Energy has initiated numerous activities to identify strategies to disposition various excess fissile materials. Two such materials are the off-specification highly enriched uranium-235 oxide powder and the uranium-233 contained in unirradiated nuclear fuel both currently stored at the Idaho National Engineering and Environmental Laboratory. This report describes the development of a technology that could dilute these materials to levels categorized as low-enriched uranium, or further dilute the materials to a level categorized as waste. This dilution technology opens additional pathways for the disposition of these excess fissile materials as existing processing infrastructure continues to be retired.
... Edited by DJ Barratt, MJ Allan, and AL Mular. Vancouver, BC: University of British Columbia, ... more ... Edited by DJ Barratt, MJ Allan, and AL Mular. Vancouver, BC: University of British Columbia, Department of Mining and Mineral Process Engineering. Stieger, J., D. Plummer, S. Latchireddi, and R. Rajamani. 2005. SAG mill operation at Cortez: Evolution of liner design. ...
Proceedings of the 32nd International Symposium on the Application of Computers and Operations Research in the Mineral Industry (APCOM) 2005), Tucson, USA, 30 March - 1 April 2005, 2005
Minerals Engineering, 2003
... provides a high resistance to flow of slurry, then the mill will fill with an excessive amoun... more ... provides a high resistance to flow of slurry, then the mill will fill with an excessive amount of slurry to a level past where efficient grinding occurs, and the mill will go off the grind (Austin et al ... The exceptions are the work done by Moys (1986) and Morrell and Stephenson (1996). ...
Minerals Engineering, 1997
Comminution is the most energy intensive process in mining industry and it consumes up to 3% of t... more Comminution is the most energy intensive process in mining industry and it consumes up to 3% of the total electrical energy generated in the world. More than 80% of the plant comminution is spent in the area of milling. There are three fundamental process mechanisms -Particle breakage, charge motion and discharge, that control the energy efficiency of grinding mills. Fundamentally, comminution has been considered as a combination of breakage and classification (or removal of product size particles) processes. Since the work done in comminution is proportional to the energy usage (or power draw), a great emphasis has been laid towards understanding and development of relationships between energy and breakage processes in the last few decades of research. This was followed by the development of discrete element modeling (DEM) in 1980s to understand the charge motion and this technique has been successfully used to optimize the design of shell lifters. Although the quest for efficient ...
Minerals Engineering, 2003
... provides a high resistance to flow of slurry, then the mill will fill with an excessive amoun... more ... provides a high resistance to flow of slurry, then the mill will fill with an excessive amount of slurry to a level past where efficient grinding occurs, and the mill will go off the grind (Austin et al ... The exceptions are the work done by Moys (1986) and Morrell and Stephenson (1996). ...
Minerals Engineering, 1997
Minerals Engineering
The South African style SAG (RoM) mills operate in a window that is almost exclusive from the ope... more The South African style SAG (RoM) mills operate in a window that is almost exclusive from the operation of the Australian and North American mills that have been used for the development of SAG mill models. Combining good quality, test data from the RoM mills is extending and improving these models, and assisting in a practical manner in improving our understanding of SAG/AG milling. Data from high mill loads, both in absolute filling and ball loading, have been used to extend and improve the JK SAG mill model. This improved understanding has been successfully applied to increasing the throughput of a mill by 8%. Data is presented on relationships between power and load for high mill loading. Slurry pooling is common in closed-circuit RoM mills, and the detrimental effect of this has been dramatically demonstrated at ALCOA with a mill throughput increase of over 20%. Techniques for calculating the effects of slurry pooling have been developed and a new pulp lifter system designed to...
DOE has initiated numerous activities to focus on identifying material management strategies to d... more DOE has initiated numerous activities to focus on identifying material management strategies to disposition various excess fissile materials. In particular the INEEL has stored 1,700 Kg of offspec HEU at INTEC in CPP-651 vault facility. Currently, the proposed strategies for dispositioning are (a) aqueous dissolution and down blending to LEU via facilities at SRS followed by shipment of the liquid
The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) througho... more The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) throughout the United States. Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes 10,000 to 100,000 tons per day the energy expenditure in grinding is 50 percent of the cost of production of the metal. A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Kennecott Utah Copper Corporation, Process Engineering Resources Inc. and others. In the current project, Cortez Gold Mines played a key role in facilitating the 26-ft SAG mill at Cortez as a test mill for this study. According to plant personnel, there were a number of unscheduled shut downs to repair broken liners and the mill throughput fluctuated depending on ore type. The University team had two softwares, Millsoft and FlowMod to tackle the problem. Millsoft is capable of simulating the motion of charge in the mill. FlowMod calculates the slurry flow through the grate and pulp lifters. Based on this data the two models were fine-tuned to fit the Cortez SAG will. In the summer of 2004 a new design of shell lifters were presented to Cortez and in September 2004 these lifters were installed in the SAG mill. By December 2004 Cortez Mines realized that the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling and operators had to learn more. Now the power consumption is 0.3-1.3 kWh/ton lower than before. The actual SAG mill power draw is 230-370 kW lower. Mill runs 1 rpm lesser in speed on the average. The re-circulation to the cone crusher is reduced by 1-10%, which means more efficient grinding of critical size material is taking place in the mill. All of the savings have resulted in reduction of operating cost be about 0.023−0.023-0.023−0.048/ ton.
The United States Department of Energy has initiated numerous activities to identify strategies t... more The United States Department of Energy has initiated numerous activities to identify strategies to disposition various excess fissile materials. Two such materials are the off-specification highly enriched uranium-235 oxide powder and the uranium-233 contained in unirradiated nuclear fuel both currently stored at the Idaho National Engineering and Environmental Laboratory. This report describes the development of a technology that could dilute these materials to levels categorized as low-enriched uranium, or further dilute the materials to a level categorized as waste. This dilution technology opens additional pathways for the disposition of these excess fissile materials as existing processing infrastructure continues to be retired.
... Edited by DJ Barratt, MJ Allan, and AL Mular. Vancouver, BC: University of British Columbia, ... more ... Edited by DJ Barratt, MJ Allan, and AL Mular. Vancouver, BC: University of British Columbia, Department of Mining and Mineral Process Engineering. Stieger, J., D. Plummer, S. Latchireddi, and R. Rajamani. 2005. SAG mill operation at Cortez: Evolution of liner design. ...
Proceedings of the 32nd International Symposium on the Application of Computers and Operations Research in the Mineral Industry (APCOM) 2005), Tucson, USA, 30 March - 1 April 2005, 2005
Minerals Engineering, 2003
... provides a high resistance to flow of slurry, then the mill will fill with an excessive amoun... more ... provides a high resistance to flow of slurry, then the mill will fill with an excessive amount of slurry to a level past where efficient grinding occurs, and the mill will go off the grind (Austin et al ... The exceptions are the work done by Moys (1986) and Morrell and Stephenson (1996). ...
Minerals Engineering, 1997
Comminution is the most energy intensive process in mining industry and it consumes up to 3% of t... more Comminution is the most energy intensive process in mining industry and it consumes up to 3% of the total electrical energy generated in the world. More than 80% of the plant comminution is spent in the area of milling. There are three fundamental process mechanisms -Particle breakage, charge motion and discharge, that control the energy efficiency of grinding mills. Fundamentally, comminution has been considered as a combination of breakage and classification (or removal of product size particles) processes. Since the work done in comminution is proportional to the energy usage (or power draw), a great emphasis has been laid towards understanding and development of relationships between energy and breakage processes in the last few decades of research. This was followed by the development of discrete element modeling (DEM) in 1980s to understand the charge motion and this technique has been successfully used to optimize the design of shell lifters. Although the quest for efficient ...
Minerals Engineering, 2003
... provides a high resistance to flow of slurry, then the mill will fill with an excessive amoun... more ... provides a high resistance to flow of slurry, then the mill will fill with an excessive amount of slurry to a level past where efficient grinding occurs, and the mill will go off the grind (Austin et al ... The exceptions are the work done by Moys (1986) and Morrell and Stephenson (1996). ...
Minerals Engineering, 1997
Minerals Engineering
The South African style SAG (RoM) mills operate in a window that is almost exclusive from the ope... more The South African style SAG (RoM) mills operate in a window that is almost exclusive from the operation of the Australian and North American mills that have been used for the development of SAG mill models. Combining good quality, test data from the RoM mills is extending and improving these models, and assisting in a practical manner in improving our understanding of SAG/AG milling. Data from high mill loads, both in absolute filling and ball loading, have been used to extend and improve the JK SAG mill model. This improved understanding has been successfully applied to increasing the throughput of a mill by 8%. Data is presented on relationships between power and load for high mill loading. Slurry pooling is common in closed-circuit RoM mills, and the detrimental effect of this has been dramatically demonstrated at ALCOA with a mill throughput increase of over 20%. Techniques for calculating the effects of slurry pooling have been developed and a new pulp lifter system designed to...
DOE has initiated numerous activities to focus on identifying material management strategies to d... more DOE has initiated numerous activities to focus on identifying material management strategies to disposition various excess fissile materials. In particular the INEEL has stored 1,700 Kg of offspec HEU at INTEC in CPP-651 vault facility. Currently, the proposed strategies for dispositioning are (a) aqueous dissolution and down blending to LEU via facilities at SRS followed by shipment of the liquid
The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) througho... more The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) throughout the United States. Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes 10,000 to 100,000 tons per day the energy expenditure in grinding is 50 percent of the cost of production of the metal. A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Kennecott Utah Copper Corporation, Process Engineering Resources Inc. and others. In the current project, Cortez Gold Mines played a key role in facilitating the 26-ft SAG mill at Cortez as a test mill for this study. According to plant personnel, there were a number of unscheduled shut downs to repair broken liners and the mill throughput fluctuated depending on ore type. The University team had two softwares, Millsoft and FlowMod to tackle the problem. Millsoft is capable of simulating the motion of charge in the mill. FlowMod calculates the slurry flow through the grate and pulp lifters. Based on this data the two models were fine-tuned to fit the Cortez SAG will. In the summer of 2004 a new design of shell lifters were presented to Cortez and in September 2004 these lifters were installed in the SAG mill. By December 2004 Cortez Mines realized that the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling and operators had to learn more. Now the power consumption is 0.3-1.3 kWh/ton lower than before. The actual SAG mill power draw is 230-370 kW lower. Mill runs 1 rpm lesser in speed on the average. The re-circulation to the cone crusher is reduced by 1-10%, which means more efficient grinding of critical size material is taking place in the mill. All of the savings have resulted in reduction of operating cost be about 0.023−0.023-0.023−0.048/ ton.