Research and Industrial Application of High-Performance Battery-Grade Manganese Tetroxide Preparation Technology

以高纯硫酸锰溶液为原料，采用空气氧化法制备四氧化三锰，研究了反应温度、反应时间、Mn2+浓度、碱液浓度即pH对四氧化三锰产品主要性能指标锰含量和振实密度的影响，并对四氧化三锰产品进行了粒度和微观形貌分析。研究结果表明，电池级四氧化三锰的适宜反应条件为：体系中pH 9.4，初始硫酸锰溶液浓度1.3 mol·L−1，反应温度70℃，反应时间25 h。在此工艺条件下，制备得到的四氧化三锰Mn含量在71.40%以上，振实密度在2.71 g·cm−3以上，粒度呈正态分布，中位径D50为10 μm左右，产品结构紧密，颗粒形貌为类球形，满足生产高端锰酸锂对原材料的要求，本研究成果已在广西锰华公司实现了规模产业化应用，产能达到10,000吨电池级四氧化三锰/年，成为了广西生产电池级四氧化三锰的龙头企业。Using high-purity manganese sulfate solution as the raw material, manganese tetroxide (Mn3O4) was synthesized via the air oxidation method. The effects of reaction temperature, reaction time, Mn2+ concentration, alkali concentration (i.e., pH), and other parameters on the manganese content and tap density of the Mn3O4 product were systematically investigated. Additionally, particle size distribution and microstructure analysis of the product were conducted. The results indicate that the optimal reaction conditions for producing battery-grade Mn3O4 are as follows: pH 9.4 in the system, initial manganese sulfate concentration of 1.3 mol·L−1, reaction temperature of 70˚C, and reaction duration of 25 hours. Under these conditions, the prepared Mn3O4 exhibits a manganese content exceeding 71.40%, a tap density above 2.71 g·cm−3, and a normal particle size distribution with a median particle size (D50) of approximately 10 μm. The product demonstrates a compact structure and quasi-spherical morphology, meeting the requirements for raw materials in high-performance lithium manganate production. This research achievement has been successfully scaled up for industrial application at Guangxi Menghua Co., Ltd., achieving an annual production capacity of 10,000 tons of battery-grade Mn3O4, establishing the company as a leading enterprise in Guangxi for battery-grade Mn3O4 manufacturing.