细粒硫化铜矿与易泥化钙镁矿物的浮选分离

承德某硫化铜矿铜品位仅为0.44%,脉石矿物主要为蛇纹石及方解石等钙镁矿物。针对黄铜矿粒度细、脉石矿物易泥化而导致黄铜矿分选效率低的特点,采用"一段脱泥-二段分级分选"的工艺流程,并使用酸化水玻璃作为脉石矿物的主要抑制剂,进行了硫化铜矿选矿试验,取得精矿品位13.97%,回收率82.98%的良好分选指标。通过对矿石的扫描电子显微镜(SEM)分析、单矿物Zeta电位及润湿接触角的测定,表明黄铜矿与蛇纹石及方解石的异相凝聚是其难选的主要原因。酸化水玻璃可以显著降低蛇纹石及方解石的表面动电位,在p H=7~9的浮选区间内使其电位由正变负,消除与黄铜矿的异相凝聚;酸化水玻璃中最具活性的硅酸胶粒可强烈吸附在蛇纹石及方解石表面,增强其亲水性,从而有利于与黄铜矿的浮选分离。

Flotation Separation of Fine Copper Sulfide and Easy- sliming Calcium-magnesium Minerals

There is a large scale of copper sulphide ore deposit in ChengDe, and the grade of copper is only 0.44%. The gangue minerals are mainly calcium-magnesium minerals such as serpentine and calcite. The separation efficiency in copper flotation is very low, because chalcopyrite has fine particle and gangue minerals slime easlily. The flowsheet of desliming in the first stage and hierarchical separation in the second stage was carried out to conduct the beneficiation experiment, with using the acid treated sodium silicate as the main inhibitors of gangue minerals. In closed circuit experiment, copper concentrate with copper grade of 13.97% and recovery of 82.98% was obtained. The results showed that the heterocoagulation of chalcopyrite with serpentine and calcite is the main reason of refractoriness for this copper ore, through the analyzes of SEM images, zeta potential measurements and contact angle measurements. The Zeta-potential of serpentine and calcite were decreased significantly from positive to negative with acid treated sodium silicate, so the heterocoagulationof chalcopyrite with gangue minerals could be eliminated. The colloidal silicas in acid treated sodium silicate have highly active hydroxy and can adsorb on the surface of serpentine and calcite strongly. So the acid treated sodium enhanced the gangue minerals hydrophilicity, and facilitated the flotation separation of chalcopyrite.