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Improving the energy efficiency of large grinding mills is of great importance to reduce the energy cost of mineral processing. The ratio of SAG mill to ball mill's energy consumption varies greatly among SABC operations. Thus far, very few research studies have been conducted to demonstrate how the SAG mill or ball mill responses to the change of circuit energy distribution in terms of comminution efficiency. The present study investigated the energy performance of an operating SABC circuit at variable circuit energy distributions. An energy benchmarking model was used to assess the comminution energy efficiency of SAG mill, ball mill, and overall circuit. It is found that the target SABC circuit achieves the highest overall energy efficiency when 37.6% of the total circuit energy is distributed to the SAG mill and 62.4% to the ball mill. The maximum energy efficiency of this SABC circuit is approximately 25% when compared to the minimum practical energy required to carry out an equivalent comminution duty. The study also showed that the ball mill is more sensitive to the variation in circuit energy distribution than the SAG mill. [ABSTRACT FROM AUTHOR]

A method for determining the minimum practical energy for comminution was developed and is presented in this paper. An objective of the method was to determine experimentally the energy-breakage relationship for a wide size range in order to evaluate the energy performance of both crushing and grinding processes using one energy benchmarking value. Single-particle compression breakage, referred to in the field of comminution as one of the more efficient forms of mechanical comminution, was the basis for a test regimen to characterize the energy-breakage properties of ores. Existing models for impact breakage were found to be valid for single-particle compression breakage when used in a modified form. A key parameter of the adopted model, the threshold energy, was also investigated for three ore types and a range of particle sizes. The energy performance of comminution processes at a Canadian mining operation was determined by comparing the determined minimum practical energy, using the new method, with actual site specific energy requirements. In order to evaluate the energy performance of different crushing and grinding technologies, the proposed energy benchmarking method was used to compare the energy performance of alternative comminution flowsheets. [ABSTRACT FROM AUTHOR]

Abstract: Increasing energy efficiency and reducing water consumption are two of the key requirements in moving toward a more sustainable mining industry. This paper demonstrates a method of determining the lowest energy option for a mine/mill water system network. The method uses a linear programming algorithm to compare different possible combinations of supplying water to mine and mill consumers. First, a site water balance is determined and then every major water consumer and source is specified. Water sources may require pumping, cooling and/or treatment before the water meets the specifications of the water consumer. The amount of energy required for each water source to supply each consumer is calculated and then the model is solved to minimize power consumption. An example is used to illustrate the method. [Copyright &y& Elsevier]