熔盐电解二氧化锰制备锰新工艺研究

Research on production of manganese by electro-deoxidation of MnO_2

提出了以二氧化锰为原料经一步熔盐电解得到锰新工艺，具有工艺流程短、低能耗、无环境污染等特点。采用850℃的NaCl—CaCl2混合熔盐体系，以烧结后的MnO2片作为阴极，高密度石墨碳棒作阳极，在工作电压（2．8～3．2V）下进行电解。研究了不同的烧结温度、电解电压和电解时间等因素对阴极片形貌及其对电脱氧反应的影响，结果表明采用熔盐电解MnO2粉末直接制备金属Mn的最佳的工艺条件为：MnO2粉末在20MPa下压片，1000℃烧结5h后，在850℃的NaCl—CaCl2混合熔盐中加3．0V的工作电压电解13h。

A new technique with which manganese can be prepared by the electro-deoxidation from MnO2 in NaCl-CaCl2 melt at 850℃ is presented, which has a simple process, low energy cost and no environmental impact. MnO2 powders is compacted into pellets and sintered, and then attached to a current collector to form an assembled cathode, under electrolysis of constant voltage 2.8 - 3.2 V, with a high-density graphite as an anode. The influences of different sintered temperature, electrolysis voltage and time on cathode pellet appearance and electro-deoxidation reaction are studied. The results show that the optimal conditions of producing manganese by the direct electrochemical reduction of soild MnO2 are as follows： pressing MnO2 powder into pellets under 20 MPa, then sintering it at 1 000℃ for 5 hours, and electrolyzing it under 3.0 V in NaCl-CaCl2 melt at 850℃ for 13 hours.