Abstract

In this work, a thermodynamic study of zinc sulfide high temperature oxidative leaching was carried out. At the metals sulfides dissolution under oxidants action in acidic solutions several simultaneously proceeding reactions are possible. With the aim finding the proportion of potential reactions, a thermodynamic calculation was carried out using stoichiometric equations with equal oxidant consumption. Moreover, stoichiometric coefficients were chosen in such a way that reagents could exchange 1 mole of electric charge. Such an approach allows one to ensure a comparison of different oxidants’ usage effectiveness for sulfide leaching. Thermodynamic analysis results are in accordance with experimental data, which confirm that reactions with the formation of sulfur and sulfate-ions are uppermost at zinc sulfide dissolution in sulfuric acid solutions under oxygen action. Oxygen consumption and initial sulfuric acid concentration influence on proportion of this reactions and zinc equilibrium concentration in solution were investigated. Thermodynamic analysis showed that at insufficient acid concentration, which limits the maximum degree of zinc sulfide oxidation reaction advancements with sulfur formation, oxygen is consumed on oxidation reaction with the formation of sulfate-ions, which spend oxygen less effectively, due to four times smaller zinc dissolution. Thermodynamic calculations carried out allowed us to find out optimal proportions of oxygen consumption and initial sulfuric acid concentration, which provide achievement of a maximal zinc equilibrium concentration in solution at a higher effectiveness of oxidant consumption without labor-intensive experiments. At optimal acid consumption, a zinc equilibrium concentration is directly proportional to initial acid concentration. Directly proportional dependence of zinc cations’ formation on acid consumption was also detected at acid concentration optimal values.

中文翻译：

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氧参与硫酸溶液中硫化锌溶解化学计量的热力学分析

摘要

在这项工作中，进行了硫化锌高温氧化浸出的热力学研究。在氧化剂作用下，金属硫化物在酸性溶液中溶解时，几种同时进行的反应是可能的。为了找到潜在反应的比例，使用具有相等氧化剂消耗的化学计量方程进行了热力学计算。此外，以使试剂可以交换1摩尔电荷的方式选择化学计量系数。这种方法可以确保比较不同氧化剂对硫化物浸出的使用效果。热力学分析结果与实验数据一致，这证实了在氧气作用下，硫化锌溶解在硫酸溶液中时，形成硫和硫酸根离子的反应最高。研究了耗氧量和初始硫酸浓度对反应比例和溶液中锌平衡浓度的影响。热力学分析表明，在酸浓度不足的情况下，这限制了硫形成时硫化锌氧化反应的最大程度，在形成硫离子的氧化反应中消耗了氧气，由于锌少了四倍，硫酸的消耗效率较低。解散。通过进行热力学计算，我们可以找到耗氧量和初始硫酸浓度的最佳比例，无需劳力密集的实验，即可在较高的氧化剂消耗效率下实现溶液中最大锌平衡浓度的达到。在最佳酸消耗量下，锌平衡浓度与初始酸浓度成正比。在酸浓度最佳值下，还检测到锌阳离子形成对酸消耗的直接比例依赖性。