摘要
The preparation of chemical manganese dioxide(CMD) from low-grade rhodochrosite ore(LGRO) in Xiushan,Chongqing,was studied and improved,including leaching with sulfuric acid,purifying,crystallizing and decomposing of MnCO3,and refining of primary MnO2.The product was characterized by X-ray diffraction.The results showed that the extraction ratio,the manganese recovery ratio of purifying,crystallization and refining reached 96.8%,93.9%,97.7%and 85.4%,respectively.The optimum conditions of refining were described as follows:liquid(H2SO4)/solid(primary MnO2) ratio was 3 L/g,the concentrations of NaClO exceeded 20%,and reaction time was 3 hours.Under the above conditions,the contents of MnO2and Mn in the obtained manganese dioxide were respectively 85.1%and 53.9%.The refined MnO2can be used as the super grade manganese dioxide mine powder in chemical industry.The XRD indicated that the structure of the product wasγ-MnO2.
The preparation of chemical manganese dioxide （CMD） from low-grade rhodochrosite ore （LGRO） in Xiushan, Chongqing, was studied and improved, including leaching with sulfuric acid, purifying, crystallizing and decomposing of MnCO3, and refining of primary MnO2. The product was characterized by X-ray diffraction. The results showed that the extraction ratio, the manganese recovery ratio of purifying, crystallization and refining reached 96.8%, 93.9%, 97.7% and 85.4%, respectively. The optimum conditions of refining were described as fol- lows： liquid （H2SO4）/solid （primary MnO2） ratio was 3 L/g, the concentrations of NaC10 exceeded 20%, and reac- tion time was 3 hours. Under the above conditions, the contents of MnO2 and Mn in the obtained manganese dioxide were respectively 85.1% and 53.9%. The refined MnO2 can be used as the super grade manganese dioxide mine powder in chemical industry. The XRD indicated that the structure of the product was 7-MnO2.
基金
Foundation by the Bureau of Land Resources and Housing Management of Chongqing(Scientific & Technologic Program in 2011)
