Reducing water and energy use in minerals processing

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The mining industry is a large employer and generator of wealth in Canada. With the recent downturn in commodity prices and continuing depletion of high-grade resources, it is necessary to develop technologies to increase the efficiency and sustainability of minerals and metals extraction. Innovation is required to ensure Canada remains competitive, and to preserve the long-term, high-paying jobs associated with primary metals processing. The objective of the research program is to develop techniques to reduce water and energy in minerals processing use while improving overall process performance. There will be a special focus on low-grade resources. Specifically, research will be conducted in four interrelated areas:****1. Microwave applications in mineral processing. Microwaves can be used to efficiently and instantaneously generate heat in materials and there is great potential for microwave technology to reduce the energy requirements of mineral beneficiation. The microwave properties of pure minerals and ores will be investigated, as will the effect of microwave treatment on the surface properties of minerals and resultant effects on mineral separation.****2. Rheology in mineral processing. Low-grade and complex ores often require fine grinding and contain problematic gangue minerals, both of which can lead to complex rheology. Dilution is one of the main strategies used in mineral processing to offset undesirable slurry rheology, which increases both water and energy use in processing. In this study, the rheology and surface chemistry of low-grade ore slurries will be examined. Correlations between slurry rheology and processability will be established, and strategies will be developed to reduce water and energy use and optimize process performance.****3. Comminution energy reduction. While energy is used in every step of mining and milling operations, the largest energy consumer is comminution. Comminution, or particle size reduction, is required for the liberation of valuable minerals from undesirable material prior to further separation. In this study, the use of particle weakening techniques, such as microwave and high-voltage pulse treatment, as well as the separation of coarse particles by flotation, will be investigated for overall comminution energy reduction.****4. Saline water use in mineral processing. Most mineral processing operations use substantial amounts of water. Due to the scarcity of fresh water in many areas, many concentrators are forced to use saline water for processing. Since the presence of substantial dissolved ions can alter water structure, particle wettability, and colloidal interactions, electrolytes have the potential to influence all aspects of mineral processing. This study will examine the effects of saline water use in grinding and flotation operations with the objective of using this resource to improve the processing of low-grade ores.***