ABSTRACT The kinetics and mechanism of the reduction of manganese dioxide ore by calcium lignosulfonate (CLS) in acid solution were investigated. The results showed that the reducing process mainly occurred after the adsorption and then decomposition of CLS by ore and the concentration of sulphuric acid exerted an enhancing effect on both CLS adsorption and manganese extraction. The effects of leaching temperature, the mass ratio of CLS to MnO2 in ore, concentration of sulphuric acid as well as leaching time on per cent leached of Mn were also discussed. The experimental data were well interpreted with a shrinking core model of internal diffusion, and an overall kinetic model was established. The reaction rate constant was found to be proportional to the mass ratio of CLS to MnO2 in ore and concentration of sulphuric acid, and the apparent activation energy was determined to be 69.4 kJ mol−1 by using Arrhenius expression.

中文翻译：

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木质素磺酸钙还原二氧化锰：动力学和机制研究

摘要 研究了木质素磺酸钙（CLS）在酸性溶液中还原二氧化锰矿石的动力学和机理。结果表明，还原过程主要发生在CLS被矿石吸附然后分解之后，硫酸浓度对CLS吸附和锰提取均有促进作用。还讨论了浸出温度、矿石中CLS与MnO2的质量比、硫酸浓度以及浸出时间对Mn浸出率的影响。实验数据很好地解释了内部扩散的收缩核心模型，并建立了整体动力学模型。发现反应速率常数与矿石中 CLS 与 MnO2 的质量比和硫酸浓度成正比，