Fundamental study of in-situ gas nucleation by hydrodynamic cavitation for fine particle flotation

加拿大是世界上主要的矿业国家之一，生产60多种重要的矿物和金属，在全球范围内使用。矿业是加拿大经济的支柱，占全国GDP的近3%。然而，加拿大矿业公司在满足全球对大宗商品的需求方面面临着一些挑战。面对矿石品位下降和更严格的环境法规，创新至关重要。高品位矿石资源的迅速枯竭促使采矿和矿物加工行业探索加工低品位矿石的新技术。从低品位矿石中有效回收有价值矿物需要高能耗的细磨矿物解离和细粒浮选新技术。尺寸小于5微米的细颗粒的浮选是极其具有挑战性的，这是由于低效的气泡-颗粒碰撞和附着，由矿泥涂层复合，导致低回收率和差的选择性。由于金属氢氧化物物质和细脉石矿物颗粒在目标矿物表面上的非选择性沉淀或沉积，目标矿物颗粒上的矿泥涂层对于细颗粒浮选来说是更成问题的。提出了一种利用水力空化作用产生的微泡或纳米泡-潜伏颗粒与常规尺寸气泡两步附着的方法，以强化细粒浮选。该项目的成功将加强加拿大在可持续发展和利用自然资源方面的领导作用，并使加拿大保持在新技术开发的前沿。

Canada is one of the leading mining nations in the world, producing more than 60 vital minerals and metals that are used globally. Mining is a pillar of the Canadian economy, generating almost 3% of the national GDP. However, Canadian mining companies face a number of challenges in meeting the global demand for commodities. Innovation is critical in the face of declining ore grades and more stringent environmental regulations. The rapid depletion of high-grade mineral ore resources has driven the mining and mineral processing industry to explore new technologies to process lower grade ores. The effective recovery of valuable minerals from low grade ores requires energy-intensive fine grinding for mineral liberation and a new technology for fine particle flotation. The flotation of fine particles of sizes less than 5 micron is extremely challenging due to inefficient bubble - particle collision and attachment, compounded by slime coatings, leading to a low recovery and a poor selectivity. The slime coatings on target mineral particles are more problematic for fine particle flotation due to non-selective precipitation or deposition of metal hydroxide species and fine gangue mineral particles on the surface of target minerals. This in turn results in a loss of valuable minerals in tailings.A two-step attachment between conventional size bubble and microbubble or nanobubble-laten particles generated by hydrodynamic cavitation is proposed for enhancing fine particle flotation. The success of this project will strengthen Canada's leadership role in sustainable development and utilization of natural resources and keep Canada in the forefront of new technology development.