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

水是矿物加工中的一种工艺介质。回收水的挑战是以这样的方式处理工艺水，即水处理中使用的化学品对浮选中的矿物回收具有可忽略的负面影响，如果不是积极的协同效应的话。贱金属加工操作通常使用基于石灰的水处理工艺（WTP）来处理工艺尾矿和酸性矿山排水。当将具有高浓度的钙（Ca 2+）和硫酸根（SO 42-）离子的再循环水流并入该过程中时，石膏在硫化物矿物和二氧化硅脉石上的潜在沉淀使得两种矿物表面具有相同的表面特性，从而降低选择性和浮选回收率。通过石膏的受控成核/沉淀和结晶更好地理解沉淀的决定因素和性质，将促进沉淀物仅在脉石矿物上的形成，以获得有价值矿物的更好浮选性能，同时最大限度地减少环境影响。

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.