High-temperature ferric leaching is a promising method to improve the recovery of nonferrous metals from sulfide ores and concentrates. In this study, differences in the leaching kinetics of a sphalerite concentrate using chemical and biogenic ferric iron have been revealed. A comparison of leaching with a (i) biosolution containing ferric iron produced by microbial cells assigned to the strain Leptospirillum ferriphilum BUT, (ii) cell-free iron-containing L. ferriphilum culture liquid, and (iii) commercial reagent of ferric iron indicated that the latter allowed the maximum zinc and copper extraction into the solution. It is suggested that the products of the microbial cell lysis interacted with metal cations, decreasing their reactivity, and slowed down the removal of products from the reaction zone. This led to the formation of a dense layer of reaction products coating sulfide minerals. Probably, the rate of zinc and copper leaching was controlled by both the diffusion of the oxidant through a layer of the reaction products and a chemical reaction on the surface of mineral particles, indicating a mixed type of control. This pattern was independent of the chemical or biological origin of the ferric iron solution. The results provide new insights into the kinetic patterns and structural changes of sulfide minerals during ferric leaching and may contribute to the intensification of the processing of sulfide raw materials.

高温铁浸出是提高硫化矿石和精矿中有色金属回收率的一种很有前景的方法。在这项研究中，揭示了使用化学和生物三价铁的闪锌矿精矿浸出动力学的差异。浸出与 (i) 由分配给嗜铁钩端螺旋体BUT 菌株的微生物细胞产生的含有三价铁的生物溶液，(ii) 不含细胞的含铁L. ferriphilum的生物溶液的比较培养液和 (iii) 三价铁的商业试剂表明，后者允许最大程度地将锌和铜提取到溶液中。表明微生物细胞裂解的产物与金属阳离子相互作用，降低了它们的反应性，并减慢了产物从反应区的去除。这导致形成覆盖硫化矿物的致密反应产物层。可能，锌和铜的浸出速率是由氧化剂通过一层反应产物的扩散和矿物颗粒表面的化学反应控制的，这表明控制是混合类型的。这种模式与三价铁溶液的化学或生物来源无关。