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

水是选矿过程中的一种介质。再生水面临的挑战是如何处理过程水，使水处理中使用的化学品对浮选矿物回收的负面影响可以忽略不计，如果不是积极的协同作用的话。贱金属加工企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。当流程中加入含有高浓度钙(Ca~(2+))和硫酸盐(SO_4~(2-))的循环水时，石膏在硫化矿物和硅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。通过石膏的受控成核/沉淀和结晶，更好地了解决定因素和沉淀的性质，将促进仅在脉石矿物上形成沉淀，从而更好地浮选有价值的矿物，同时将对环境的影响降至最低。

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.