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: liqu...
