硫化钠对黄铜矿无捕收剂浮选的影响

给出了碱性介质中硫化钠作还原电位调整剂时黄铜矿的无捕收剂浮选(称有硫化钠无捕收剂浮选)的行为。通过矿浆电位测试、伏安曲线、HS~-在黄铜矿表面吸附量测定和中性硫的溶剂提取一化学分析,较详细地研究了HS~-降低电位的作用和在黄铜矿表面的吸附行为。研究结果表明,经硫化钠调浆的黄铜矿矿浆的铂电位(即矿浆电位)迅速下降,在硫化钠自身调控的还原电位下,HS~-难以在黄铜矿表面发生电化学吸附;但在恒电位仪控制的高电位下,HS~-可以在黄铜矿表面发生电化学吸附。因此,HS~-存在并不能明显降低黄铜矿无捕收剂浮选的矿浆电位下限,黄铜矿有硫化钠无捕收剂浮选的矿浆电位下限与无硫化钠无捕收剂浮选(称自诱导浮选)的矿浆电位下限接近。

EFFECT OF SODIUM SULFIDE ON COLLECTORLESS FLOTATION OF CHALCOPYRITE

Collectorless flotation behavior of chalcopyrite in the presence of Na_2S as a modifier of reducing potential, which is also called collectorless flotation with Na_2S, has been provided. Both the action of decreasing potential by HS~- ion and the adsorption of HS~- ion have been investigated through measurement of pulp potential, voltammetry, measurement of HS~- adsorption density, and solvent extraction-chemical analysis. The results have shown that because of Na_2S addition, the platinum electrode potential of flotation pulp of chalcopyrite decreases rapidly. At the lower potential controlled by HS~- itself, the electrochemical adsorption of HS~- ion on chalcopyrite will not take place, and thus HS~- will not be oxidized into neutral sulfur(S~0).But at higher potential controlled by potentiostat, HS~- ion can be oxidized into neutral sulfur on the chalcopyrite surface. Therefore, the presence of HS~- ion will not decrease the lower limit of pulp potential for collectorless flotation of chalcopyrite and not improve the flotation behavior. The lower limit of pulp potential for collectorless flotation with Na_2S is approximate to that for collectorless flotation without Na_2S.