难处理金矿细菌氧化工艺中和水的成分分析

通过对中和水及结晶物进行的化学分析和X射线粉晶分析,查明中和水中含有大量的Mg,K,Na,Ca物质;其结晶物主要是硫酸盐:MgSO4·3H2O,MgSO4·4H2O,MgSO4·1 25H2O及CaSO4·2H2O·这些大量的镁和钙来源有:①细菌氧化工艺中使用的金矿中矿物成分复杂,其中含镁、含钙的碳酸盐、硅酸盐矿物较多,工艺过程中部分进入溶液,并积累起来·②用石灰进行中和时,中和后剩余的钙,停留在溶液中·中和水在复用返回细菌氧化流程时,由于镁、钙的浓度过高,会以硫酸盐形式结晶析出,造成水路堵塞,同时高浓度的镁会抑制浸矿细菌的生长,对工艺带来不利的影响·

Compositional Analysis of Neutralized Water Through Bio-Oxidation for Refractory Gold Ores

Chemical analysis and X-ray powder crystal analysis were made to neutralized water and crystallization contained in it. It was found that there are a large amount of substances containing magnesium, potassium, sodium and calcium in neutralized water, of which the crystallization is mainly in form of sulphates including MgSO4·3H2O, MgSO4·4H2O, MgSO4·1.25H2O and CaSO4·2H2O. Such a large amount of magnesium sulphates or calcium sulphate come from two processes. One is the bio-oxidation in which the mineral composition of the gold ore used is complicate with many carbonates/silicates bearing magnesium/calcium and part of them dissolve into the solution cumulatively. The other is the neutralization using limestone, after which the residual calcium deposits in the solution. Neutralized water always cause the water pipeline to jam up when it is used cyclically in bio-oxidation process because of the high-concentration magnesium/calcium and, at the same time, the high-concentration magnesium will suppress the growth of bioleaching bacteria then result in adverse effect on bio-oxidation process.