燕麦秸秆还原浸出低品位软锰矿及其动力学

摘要

以燕麦秸秆为还原剂，在硫酸介质中直接浸出某低品位软锰矿，研究浸出过程的工艺条件和动力学。结果表明：在硫酸浓度为150 g/L、液固比为9 mL/g、麦秆与软锰矿质量比为0.3、浸出温度90℃、浸出60 min的条件下，锰浸出率可达96.1%，此时，铁浸出率为46.8%，浸出液化学需氧量(COD)值为6.2 g/L。动力学研究表明：锰的浸出过程在333~363 K内符合未反应核缩减模型，浸出过程主要受界面化学反应步骤控制，其浸出表观活化能为69.4 kJ/mol。%The extraction of manganese from low-grade pyrolusite ore was investigated using oat straw as a reducing agent in dilute sulfuric acid medium. The optimal conditions and the kinetics from manganese dioxide ores by reductive leaching were discussed. The results show that the leaching rate of manganese reaches 96.1%while the iron dissolved is 46.8%and chemical oxygen demand (COD) is 6.2 g/L under the optimal condition as follows, H2SO4 concentration of 150 g/L, liquid-to-solid ratio of 9 mL/g, mass ratio of oat straw to pyrolusite ore of 0.3, leaching time of 60 min at 90℃. The kinetics studies indicate that the leaching process follows the shrinking-core model in the temperature ranging from 333 K to 363 K, the leaching rate of manganese is controlled by the interface chemical reaction during the leaching process, and the apparent activation energy is 69.4 kJ/mol.