硫酸锰室温固相球磨制备四氧化三锰

利用软锰矿吸收硫酸镁热解尾气二氧化硫制得硫酸锰，再与碳酸氢铵室温下固相球磨反应，制备出前躯体碳酸锰，经热分解获得四氧化三锰。分别考察了物料比、球磨时间、球料比等因素对硫酸锰转化率的影响，采用XRD对产物进行了分析。结果表明，在n（碳酸氢铵）∶n（硫酸锰）=3.5∶1、球磨时间为40 min、球料质量比为5∶1时，硫酸锰的转化率可达99.8%，将固相产物在1 000 ℃热解1 h后所制备的四氧化三锰纯度为99.9%。该工艺操作简单，产品纯度高，成本低，为硫酸锰制备四氧化三锰提供了新的途径。

Preparation of Mn3O4 from manganese sulfate by solid-state ball milling reaction at room temperature

Manganese sulfate was prepared by reaction between pyrolusite and sulfur oxide from the pyrolysis of magnesium sulfate.Mn₃O₄ can be prepared by pyrolysing the precursor MnCO₃.The precursor was synthesized by solid-state ball milling reaction between NH₄HCO₃ and MnSO₄·H₂O at room temperature.Effects of materials mix ratio，milling time，and ball-feed mass ratio on the conversion of manganese sulfate were investigated respectively.The products were analyzed by XRD.Results showed that the conversion rate of MnSO₄·H₂O could reach 99.8% under the conditions of mix ratio 3.5∶1（amount-of-substance ratio of NH₄HCO₃ to MnSO₄·H₂O），milling time 40 min，and ball-feed mass ratio 5∶1.The Mn₃O₄，whose purity was 99.9%，can be prepared by pyrolysing manganese carbonate at 1 000 ℃ for 1 h.The process has the advantages of simple in operation，high product purity，and low cost，and it can provide a new route for the preparation Mn₃O₄ from MnSO₄·H₂O.