硫酸锰在氨性介质中制备四氧化三锰的研究

研究了硫酸锰溶液在氨性介质中锰离子水解沉淀的机理和锰离子的沉淀率，还研究了硫酸锰水解产物的氧化。结果表明：硫酸锰溶液的水解产物是氢氧化锰和碱式硫酸锰的混合物。混合物中的氢氧化锰优先于碱式硫酸锰氧化，氧化产物四氧化三锰硫含量偏高是碱式硫酸锰很难被完全氧化所致。温度为30℃和pH为10．4时，锰离子的沉淀率仅为87．3％，锰离子与氨发生络合反应是造成其沉淀率小的主要原因。

A Study on Preparation of Mn3O4 by Oxidizing Hydrolysis of Manganese Sulfate with Air in Ammonia Alkalescence Media

The mechanism of manganese ion hydrolysis and precipitation rate of manganese ion in ammonia alkalescence media were investigated, and the experiments for oxidization of hydrolysates of manganese sulphate were carried out further. The results indicate that the hydrolysate of manganese sulphate is a mixture containing manganese hydroxide and manganese hydroxysulfate, the manganese hydroxide in mixture is oxidized more easily than manganese hydroxysulfate, the high level of sulphate in Mn304 product is caused by manganese hydroxysulfate that is oxidized difficultly. At pH value 10.4 and 30℃, rate of manganese ion precipitation is 87.3%, the complex reaction of manganese ion with ammonia molecule is main reason for a lower manganese ioo precipitation rate.