氯化铵焙烧菱锰矿制备高纯碳酸锰的工艺研究

以低品位菱锰矿和工业级氯化铵为原料，通过研磨混合、焙烧、水浸取富集回收锰。实验结果表明：当氯化铵用量为锰矿粉质量的1.1倍、500 ℃下焙烧1 h时，锰的浸出率可达95%以上；并且通过二级吸收的方式实现了焙烧尾气二氧化碳和氨气的回收利用，探索出一条可行的清洁生产工艺路线，避免了环境污染。由于大量金属杂质伴随锰的富集过程同时浸出，实验对锰浸出液进行了中和水解除铁、氟化铵沉淀钙镁等除杂处理，得到满足后续碳化工艺要求的锰净化液，碳化结晶制备出符合HG/T 2836-1997《软磁铁氧体用碳酸锰》要求的高纯碳酸锰产品。

Preparation of high-purity manganese carbonate from rhodochrosite by ammonium chloride roasting method

Using low-grade rhodochrosite and industrial NH4Cl as raw materials,manganese(Mn) was enriched and recovered by the processes of grinding,mixing,roasting,and water leaching.Experiment results showed that Mn leaching rate can reach more than 95%,when the mass ratio of NH4Cl and rhodochrosite was 1.1 and roasting at 500 ℃ for 1 h;and the technology realized the recovery and utilization of roasting tail gas(CO2 and NH3) by two-stage absorption way.It was nece-ssary to remove large amount of metal impurities that leaching together with manganese.After hydrolysis to remove iron and NH4F to precipitate Ca and Mg,purified manganese solution which meet the requirements of the subsequent carbonization and crystallization processes was obtained.At last,the high-purity manganese carbonate was crystallized,which conformed to the standard of Manganese Carbonate for Soft Ferrite Use(HG/T 2836—1997).