Study On Preparation Of Chemical Manganese Dioxide Leaching Of Electrolytic Manganese Anode Slime Reduction For Corn Stalk

The chemical activity of manganese dioxide anode slime is difficult to be recycled for long time because of its complex composition and low chemical activity. Corn straw can be used as a low cost and wide source of organic reducing agent. CMD can be prepared by the reduction leaching of manganese anode slime with corn straw which makes waste resources two times recycling and reuse. This paper studied the preparation process of each link, and explored the influence of relevant process parameters of each stage to the final quality of CMD product. Combined with relevant theoretical analysis, the optimum parameters were obtained by using corn stalk reduction leaching of manganese anode slime, researched the link technology development direction, and verified by experiment. Compared with lean rhodochrosite synthesis for the preparation of CMD products, then the two kinds of method for the production of final CMD product performance differences were gained.Manganese carbonate pyrolysis method is a commonly used method for preparation of CMD process. The process can be divided into four stages, including manganese sulfate solution preparation, carbonation and crystallization, primary manganese dioxide preparation and refined products. The preparation of manganese sulfate solution includes two stages, the reduction leaching of corn stalk and the impurity of leaching solution, which determine the recovery of the electrolytic manganese anode slime and the purity of the final product. The tap density of manganese carbonate effects obviously by various process conditions of carbonation and crystallization, thereby affecting the CMD s tap density, but the electrical activity little affected. The carbonate manganese products with the apparent density of 2.1g/cm3 can be obtained by reasonably arranging the dosage of ammonium bicarbonate, the way of administration, crystallization temperature and reaction time. In the part of primary manganese dioxide preparation, react time and temperature determine the thermal efficiency and the formation of the crystal type. The results show that the MnO2 content of product is 68.96%at 380℃ after 6h of pyrolysis. And the crystal type is y-MnO2 with the highest of electrochemical activity. In the part of refinement of the product, the acid treatment and oxidation of primary manganese dioxide can further purification and improve the morphology of particles and increase the tap density. On a comprehensive consideration of the reality of the conditions of production, economic costs, etc, in the optimal parameters for each stage of process, the MnO2 content reached 91.29%, tap density for 1.83g/cm3, and the capacitance of chemical manganese dioxide product for 251.6mAh eventually. Prepared with lean rhodochrosite of chemical manganese dioxide product, the MnO2 content of CMD-2 is up to 91%, tap density for 1.90g/cm3, capacitance for 249.43 mAh. Thus, the two methods effect roughly the same in the tap density and the discharge activity, which can achieve the level of high-quality chemical manganese dioxide.