高含盐水对浮选的影响与应对措施研究进展

Advances of researches on the influence of high-salinity waters on the flotation and relevant countermeasures

采用高盐分、高硬度的海水、苦卤水、高循环选矿回水等高含盐水进行浮选将是未来沿海缺水地区选矿行业发展的必经之路,这些高含盐水中高浓度离子对矿物浮选的影响机理一直是选矿研究的热点之一。本文回顾了国内外学者在海水、苦卤水、高循环选矿回水等对矿物浮选影响及其作用机制方面的研究工作,系统分析了高含盐水中离子对浮选气泡、矿物表面性质以及浮选药剂的影响。高含盐水给矿物浮选带来众多积极影响,包括降低气泡表面张力产生数量更多、稳定性更强的气泡,提高矿化泡沫形成几率;压缩矿物表面双电层,减弱矿物颗粒之间的静电力,减小细粒脉石矿物浮选过程中的夹带等。同时,高含盐水中的离子也会消耗浮选药剂,且强碱性条件下高价碱金属离子在矿物表面形成亲水沉淀降低矿物可浮性,影响选矿指标。针对高含盐水的负面影响,认为主要应对措施包括研发消除高钙镁离子影响和高耐受性药剂以及淡化、软化高盐水,这也是未来使用高含盐水浮选必然关注的重点。

The utilization of high-salinity and high-hardness seawater,brine water,high-recirculating flotation tailing water,and other high-salinity waters for the mineral flotation will be a necessary path for the development of the mineral processing industry in the water-shortage coastal areas in the future.The mechanism of the effect of high-concentration ions in these high-salinity waters on the mineral flotation has always been one of the hot research topics in the field of mineral processing.In this article,we have reviewed researches of domestic and foreign scholars on effects and mechanisms of seawater,brine water,high-recirculating flotation tailing water,and other high-salinity waters on the mineral flotation,and have systematically analyzed effects of ions in high-salinity waters on flotation bubbles,mineral surface properties,and flotation reagents.There are many positive effects of high-salinity waters on the mineral flotation.They include the reduction of the surface tension of bubbles,production of more and more stable bubbles,improvement of the formation probability of flotation foam,compression of double electric layer on the mineral surface,reduction of the electrostatic force between mineral particles,and reduction of the entrainment of fine-grained gangue minerals in the flotation process.Meanwhile,the ions in high-salinity waters can consume flotation reagents.Hydrophilic precipitants on the mineral surface formed by high-valence alkali metal ions under the strong alkaline condition resulted in the reduction of the mineral floatability and the beneficiation indicators.Regarding to the negative effects of high-salinity waters on the mineral flotation,it is believed that main countermeasures include to develop methods for eliminating the influence of high-calcium and magnesium ions,to develop high-tolerance reagents,and to desalinate and soften high-salinity waters.They are also inevitably focused key points for the mineral flotation by using high-salinity waters in the future.