Controlled gypsum nucleation and crystallization for improving water treatment and lead-zinc separation at red dog operation

水是矿物加工中的工艺介质。再生水面临的挑战是如何处理工艺用水，使水处理中使用的化学品对浮选中的矿物回收产生的负面影响即使不是积极的协同效应，也可以忽略不计。贱金属加工作业通常使用石灰基水处理工艺（WTP）处理工艺尾矿和酸性矿山废水。当加入含有高浓度钙（Ca2+）和硫酸盐（SO4 2-）离子的循环水流时，石膏在硫化矿物和硅脉石上的潜在沉淀使两种矿物表面具有相同的表面特征，从而降低了选择性和浮选回收率。通过控制石膏的成核/沉淀和结晶，更好地了解沉淀的决定因素和性质，将促进脉石矿物上沉淀的形成，从而提高有价值矿物的浮选性能，同时最大限度地减少对环境的影响。

Water is a process medium in mineral processing. The challenge for reclaim water is to treat the process water in such a way that chemicals used in water treatment have a negligible negative impact, if not a positive synergistic effect, on mineral recovery in flotation. Base metal processing operations often treat process tailings and acid mine drainage using a lime-based water treatment process (WTP). When a recycle water stream with a high concentration of calcium (Ca2+) and sulphate (SO4 2-) ions is incorporated in the process, potential precipitation of gypsum on both sulfide minerals and silica gangues makes both mineral surfaces of the same surface characteristics, thus decreasing the selectivity and flotation recovery. A better understanding of the determinants and the nature of precipitation through the controlled nucleation/precipitation and crystallization of gypsum will enhance the formation of precipitates only on gangue minerals for a better flotation performance of valuable minerals while minimizing environmental impacts.