采用微生物冶金方法对黄铜矿与铁闪锌矿的共生矿物进行了分步浸出研究。嗜铁钩端螺旋菌(Leptospirillus ferriphilum)浸出体系中,通过改变外加Fe3+浓度,分析了浸出过程中溶液电位、铜铁离子浓度的变化情况,考察了Fe3+浓度对铜铁分步浸出的影响。结果表明,外加0.06 mol/L Fe3+浸出3 d,锌浸出率从5.630%提高至16.288%,铜浸出率从2.372%提高到10.731%;浸出初期外加适量Fe3+有利于铁闪锌矿优先溶解;外加大量Fe3+时,对铜铁浸出均有明显促进作用,但二者分步浸出趋势减弱;外加Fe3+可加速元素硫的氧化,削弱浸出过程中硫膜对矿物浸出的阻碍,同时降低溶液p H值,加速矿物浸出;但Fe3+浓度过高时,大量黄钾铁矾的生成阻碍了矿物溶解。
Research on stepwise leaching of the associated minerals of marmatite and chalcopyrite was conducted adopting bio-hydrometallurgy method. The effect of Fe3+ concentration on stepwise biofeaching of chalcopyrite and marmatite with Leptospirillus lerriphilum system was investigated based on analyzing redox potential, concentration variations of copper,ferrous and ferric ions. Results show that the leaching process for 3 d by adding 0.06 mof/L Fe3+ led to extraction rates of zinc and copper increased lrom 5.630% to 16.288% and lrom 2.372% to 10.731%, respectively. An appropriate addition of Fe3+ at the initial period of biofeaching promoted the dissofving of marmatite and an extra addition of Fe3+ was benelicial to the biofeaching of both copper and iron,resulting in a weakening ellect in the stepwise biofeaching. Furthermore, an addition of Fe3+ promoted the oxidation of elemental sulphur, and reduced the hindrance of passivation layer to the mineral leaching, as well as reduced the pH value of sofution, resulting in the biofeaching process accelerated. However, an extra high concentration of Fe3+ resulted in the mineral dissofution hindered by the lormation of jarosite.