硫酸锰为原料沉淀-氧化法制备四氧化三锰的研究  

Synthesis of Mn_3O_4 powder from manganese sulfate by precipitation-oxidation process

作　　者：何佳[1] 张昭[1] 

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《无机盐工业》2014年第3期45-49,共5页Inorganic Chemicals Industry

摘　　要：以硫酸锰、氨水为原料,空气和硝酸铵为氧化剂,通过沉淀-氧化路线制备四氧化三锰粉体。采用X射线衍射(XRD)、红外光谱(FT-IR)、扫描电镜(SEM)等手段对产物的物相、形貌特征、平均粒径进行表征。研究了硫酸锰在氨水中的水解沉淀过程以及氢氧化锰液相氧化为四氧化三锰的过程,主要研究了液相氧化过程中氧化温度、氧化时间以及随后的干燥过程对氧化的影响。实验结果表明,将硫酸锰溶液反加到氨水中的加料方式可以避免正加料方式(氨水加入到硫酸锰溶液中)形成碱式硫酸锰而造成产品中含硫量高的问题;在通空气液相氧化氢氧化锰过程中添加液相氧化剂硝酸铵可以提高氧化速率。当硝酸铵用量为3 g(硝酸铵与硫酸锰的质量比约为1∶7.5)、液相氧化温度为70℃、氧化时间为4 h、随后在空气中于120℃干燥4 h的条件下,制备的四氧化三锰产物物相纯,粒度细,硫含量低,达到电子级原料标准。Manganese oxide （Mn304） powder were prepared by precipitation-oxidation method with manganese sulfate and aqueous ammonia as raw materials, and air and ammonium nitrate as oxidants.The phase, morphology, and average particle diameter of the as-prepared samples were characterized by means of XRD, FT-IR, and SEM etc..The hydrolysis process of manganese sulfate in the aqueous ammonia as well as the process of manganese hydroxide being oxidized into Mn3O4 in liquid phase were studied.Especially, the effects of oxidation temperature ,oxidation time, and drying on the oxidation process were mainly investigated.Results showed that the formation of manganese hydroxysulfate can be reduced through negative-adding manganese sulfate dropwise into the aqueous ammonia（positive adding is：putting ammonia into manganese sulfate solution）, and ammonium nitrate adding in solution accelerated the reaction rate of manganese hydroxide oxidized by solved air.The electronic grade Mn3O4 particles with high purity, fine granularity,and low sulfur content were obtained when ammonium nitrate of 3 g was added （the mass ratio of ammonium nitrate to manganese sulfate was about 1：7.5 ）, oxidation temperature of 70 ℃, maintaining 4 h in solution, and then air drying for 4 h.

关 键 词：硫酸锰 四氧化三锰 沉淀-氧化 氧化剂 

分 类 号：TQ137.12[化学工程—无机化工]