The Analysis Of Leaching Process And Factors Of Semi-Oxidized Manganese Ore

Manganese industry is always starting from leaching manganese sulfate which is the raw material of electrolytic manganese, manganese dioxide, manganese carbonate and manganese chloride products. With the development of manganese industry and manganese ore resources exploitation, high grade rhodochrosite and pyrolusite resources become increasingly tense, so the research of low grade ore especially semi-oxidized manganese ore has important economic value and prospective significance to alleviate this situation.In this paper, the leaching behaviour of semi-oxidized manganese ore was studied. The results showed that manganese leaching rate increases with the increase of dosage of reducing agent, the dosage of sulfuric acid and reaction temperature. Under low concentration of sulfuric acid, MnCO3and MnO2will be competition behavior of hydrogen ions, and MnCO3is dominant. But the decomposition of MnO2was conducive to the decomposition of MnCO3which is wrapped in MnO2. But under high concentration of sulfuric acid, this competition behavior between them would no longer be apparent.On the mixed crystal simulation leaching experiments, MnCO3and MnO2of mixed crystal simulation could completely be leaching under the appropriate conditions. But even under the condition of high strength, semi-oxidized manganese ore could not completely be leaching, and it mainly was the manganese silicate layer of ore hindered the leaching process. By high temperature roasting activation or add infusions such as ammonium fluoride could obviously break the package, so as to improve the manganese leaching rate.The single factor experimental results show that the dosage of sulfuric acid per ore is0.828g·g-1, the amount of glucose per ore is0.060g·g-1, dosage of ammonium fluoride per ore is0.040g·g-1, liquid-solid ratio is6mL·g-1, reaction temperature is60℃, leaching time is5h, and after60min reaction under the condition of adding ammonium fluoride0.040g·g-1, while the manganese leaching rate was92.17%.The response surface method was also used to analyse the factors which was sulfuric acid, glucose, ammonium fluoride and leaching time, and the results showed that those factors ware significant, the quadratic term and the interaction between sulfuric acid glucose are also significant. There are hydrogen ion competition relations in the process of leaching reaction between ammonium fluoride and glucose. The optimized leaching process parameters are as follows:the amount of sulfuric acid per ore is0.880g·g-1, the amount of glucose per ore is 0.059g·g-1, the ammonium fluoride dosage per ore is0.04g·g-1and extraction time is6h. Under this condition, the leaching rate of manganese is93.09%, and the predicted value of93.18%. But under the same conditions without ammonium fluoride, the leaching rate is just82.37%.