蛇纹石与黄铁矿间的异相凝聚/分散及其对浮选的影响

通过浮选试验、浊度测定、ζ电位测定和吸附量测定, 研究了蛇纹石与黄铁矿间的异相凝聚/分散及其对浮选的影响。结果表明, 在pH=7～10.2, 蛇纹石与黄铁矿表面间静电力表现为引力, 颗粒间的异相凝聚严重, 且当蛇纹石量占黄铁矿量5%时, 就会显著降低黄铁矿回收率。原因是蛇纹石异相凝聚于黄铁矿表面, 不仅自身的可浮性差, 还会降低戊基黄药在黄铁矿表面的吸附量。增加捕收剂用量或添加六偏磷酸钠均能有效改善黄铁矿的浮选。六偏磷酸钠可以使蛇纹石表面ζ电位由正转负, 有效减弱异相凝聚。

Heterocoagulation/Dispersion between Serpentine and Pyrite and its Influence on Flotation

Heterocoagulation/dispersion between serpentine and pyrite and its influence on flotation were studied with flotation tests and the determination of turbidity, ζ-potential and adsorption amount. The results show that, for a pulp pH ranging from 7 to 10.2, electrostatic force between serpentine and pyrite can be characterized as attractive, and heterocoagulation among particles is strong, and when the amount of serpentine reaches 5% of that of pyrite, the recovery of pyrite can be significantly reduced. This may attribute to the coverage of serpentine on pyrite surface because of heterocoagulation, which may not only result in a poor floatability of serpentine, but also reduce the adsorption of amyl xanthate on pyrite surface. The flotation behavior of pyrite can be effectively improved by increasing collector dosage or by adding sodium hexametaphosphate (SHP), as the surface ζ-potential of serpentine can be transferred from positive to be negative by SHP, and the heterocoagulation can therefore be effectively weakened.