Molecular Engineering and Controlled Nano-assembly for Complex Sulfide Flotation in High Salinity Water

高品位矿石资源的枯竭，促使加拿大矿业和选矿行业不断探索加工低品位矿石的新技术。要想从低品位矿石中有效回收有价矿物，需要进行高强度的细磨解离和细粒浮选新技术。随着环境法规对零排放的要求越来越严格，循环水被用于矿物加工和油砂开采。因此，循环水中的盐度或总溶解固形物（TDS）显著增加。这些离子浓度的升高，以及金属氢氧化物在高pH下的沉淀，阻碍了捕收剂与矿物表面的反应，降低了选择性。这些问题限制了回收高盐度水或海水在选矿中的有效性。

The depletion of high-grade mineral ore resources has driven Canada’s mining and mineral processing industry to explore new technologies to process lower grade ores. The effective recovery of valuable minerals from low-grade ore requires intensive fine grinding for mineral liberation and a new technology for fine particle flotation. With increasingly stringent environment regulations for zero discharge, recycled water is used for mineral processing and oil sands extraction. As a result, salinity or total dissolved solids (TDS) in the recycled water has increased significantly. These elevated ionic concentrations, as well as the precipitation of metal hydroxides at high pH, retard the collector’s reaction with mineral surfaces and lower the selectivity. These problems limit the effectiveness of recycled high-salinity water or seawater in mineral processing. This discovery program is aimed at developing a breakthrough technology for fine particle flotation in high salinity and seawater. Our approach is to achieve fundamental understanding of the underlying science of the critical physiochemical properties of fine mineral particles and air bubbles in high salinity and seawater. Through controlled nano-assembly, a topography of collector molecules on the surface of fine mineral particles will be designed for selective flotation in high salinity and seawater. The effects of solution chemistry on collector adsorption, air bubble coalescence, and water structure at the air-water interface will be studied in high salinity water. We will elucidate the relationship of molecular structure and topography on mineral surfaces to flotation recovery and selectivity. The interaction forces between bubbles and mineral surfaces in high salinity water will be studied by atomic force microscopy (AFM). This fundamental knowledge lays the foundation for further development of revolutionary fine particle flotation technologies so that our limited mineral resources can be used responsibly with minimum environmental footprint. Scientifically, we anticipate breakthroughs in understanding the nature of molecular nano-assembly structure and interaction forces.