钛白废酸-软锰矿-硫铁矿制备高纯硫酸锰

摘要

研究以硫铁矿为还原剂,在钛白废酸中湿法还原软锰矿制备硫酸锰的工艺过程.探讨反应温度、反应时间、酸矿比和矿浆浓度等因素对硫酸锰浸出率的影响.实验结果表明:在反应温度为95℃、反应时间为2.5 h、硫铁矿与软锰矿(以锰计)的质量比为0.95～1.0、硫酸与软锰矿(以锰计)的质量比为130、矿浆质量分数为28％～30％的条件下,硫酸锰的浸出率达到95％以上.通过加入碳酸钙中和浸出溶液使其pH为5～6,以除去溶液中的铁、钛、铝等杂质:加入自制硫化锰以除去溶液中的重金属离子；加入二氟化锰以除去溶液中的钙镁离子等.所得溶液经陈化、过滤、浓缩和结晶后得高纯一水硫酸锰,产品纯度为99％以上.%The production process for manganese sulfate by reducing pyrolusite in the titanium white (TiO2) waste acid,with pyrite as the reducing agent was studied.Influence of reaction temperature,reaction time,mass ratio of acid to mineral,and concentration of pulp etc.on leaching rate of manganese sulfate was investigated.Experimental results showed that,under the optimum conditions of reaction temperature 95 ℃,reaction time 2.5 h,mass ratio of pyrite to pyrolusite (calculated by manganese) at 0.95～1.0,mass ratio of vitriol to pyrolusite 1.30,and mass fraction of pulp at 28％～30％,the leaching rate of manganese sulfate was more than 95％.Furthermore,adjusted pH to 5～6 for removing iron,titanium,aluminium ions with calcium carbonate,removed the heavy metal ions by self-made manganese sulphide,and eliminated Ca,Mg ions by manganese difluoride,then the resultant solution treated through aging,filtration,concentration,and crystallization,finally the purity of obtained product MnSO4· H2O was more than 99％.