Preparation Of Mn And Mn-fe Alloy By Ffc Cambridge Process

FFC Cambridge process, a new technique which has a short route, low energy consumption and no environmental influence is used to reduce solid MnO₂, Fe₂O₃(or mixed oxides of MnO₂ and Fe₂O₃)directly to Mn, Fe(or FeMn4 alloy)in molten CaC12?NaCl at 850℃, MnO₂, Fe₂O₃ or MnO₂-Fe₂O₃ powders were compacted into pellets and sintered, and then conducted as a cathode, while a high?density graphite rod as an anode. Electrolysis was carried out under constant cell voltage. The influences of compacted pressure, sintering temperature, cell voltage and parcicle size on the electro?deoxidation were investigated by SEM, XRD, current curves and porosity.Results showed that the optimal conditions of MnO₂ directly to be made into Mn by the novel electrochemical method are: MnO₂ pellets were compacted at 20MPa, sintered at 1000℃for 5h and electrolyzed for 13h under 3.00V in molten CaCl₂-NaCl at 850℃. By the comprehensive analysis of the influencing factors of process of sintering and electrolysis, reaction mechanism on preparation of Mn was disscussed.The optimal conditions of Fe₂O₃ directly to be made into Fe by the novel electrochemical method were: Fe₂O₃ pellets are compacted at 10MPa, sintered at 800℃for 5h and electrolyzed for 13h under 3.00V in molten CaCl₂-NaCl at 850℃.The optimal conditions of MnO₂?Fe₂O₃ directly to be made into FeMn4 by the novel electrochemical method are: MnO₂?Fe₂O₃ mixed powders were ball-milled for 3h, compacted at 20MPa, sintered at 800℃for 5h, and then electrolyzed for 18h under 3.20V in molten CaCl₂-NaCl at 850℃. The result showed that MnO₂ and Fe₂O₃ were reduced separately to MnO and Fe, after that, FeMn4 alloy was obtained. In the process of preparation of FeMn4, particle size of metal mixture has also decided the electric?deoxidization rate, and had a direct impact on the generation of FeMn4, in addition to compacted pressure, sintering temperature and cell voltage.