锰方解石的盐酸浸出及四氧化三锰的制备

Hydrochloric acid leaching of manganocalcite and preparation of manganese tetraoxide

对锰方解石的盐酸浸出行为进行研究并采用石灰乳法制备四氧化三锰;采用X线衍射对产品Mn3O4进行表征,考察液固比、催化剂用量、反应温度、浸出时间和搅拌速度等因素对锰浸出率的影响,并从动力学角度分析浸出行为。为了提高产品四氧化三锰的纯度,采用正交实验研究石灰乳浓度为1 mol/L时,Mn2+浓度、反应温度、石灰乳加料速度以及反应陈化时间对氢氧化锰纯度的影响。研究结果表明:锰浸出率随温度和搅拌速度的增大而增大;催化剂可在一定程度上缩短反应时间;锰方解石矿的浸出过程为扩散化学反应混合控制过程;当氯化锰浓度为0.5 mol/L,反应温度为80℃,陈化时间为4 h,加料速度为6 mL/min时,氢氧化锰中锰质量分数可达60%以上,最终产品四氧化三锰中锰质量分数为70.42%。

The processes of preparing manganese from manganocalcite by hydrochloric acid-leaching and technological conditions of the preparation of manganese tetraoxide by lime-brine method were studied, and the crystal configuration of manganese tetraoxide was characterized by X-ray diffraction. The effects of liquid-solid ration, content of catalysts, reaction temperature, reaction time and stir speed on leaching rate were investigated, and the leaching process was analyzed by kinetics. In order to improve the purity of manganese hydroxide product, manganese ion concentration, reaction temperature, feeding speed and aging time were investigated through orthogonal experiments when the concentration of lime milk was 1 mol/L. The results show that with the increase of the reaction temperature and stir speed, the manganese leaching rate increases. Catalysts can shorten the reaction time to some extent, and the reaction is controlled by diffusion-chemical reaction hybrid controlled process. Above 60% of manganese in manganese hydroxide is achieved when feeding speed is 6 mL/min with manganese ion concentration of 0.5 mol/L at 80℃ for 4 h. The mass fraction of manganese in the product is 70.42%.