熔渣无污染短路电化学还原分析

Unpolluted short circuit electrochemical reduction analysis for molten oxide slags

在可控氧流冶金理念指导下发展了熔渣无污染短路电化学还原新方法。分析了以氧离子导体作隔离膜时从氧化物熔渣中直接提取金属的电化学还原原理。利用电池等效电路,比较了熔渣在短路、开路条件下电化学还原时氧电流的特点,讨论了熔渣还原时影响氧电流的因素。结果表明:外电路短路、降低电路中总电阻、选用更强的还原剂或采用阴极合金化等措施可以增大氧离子电流,提高熔渣电化学还原速度。实验利用碳饱和铁液作还原剂,组成如下两种电池:石墨棒|[O]Fe+C饱和|ZrO2(MgO)|FeO(slag)|铁棒;石墨棒|[O]Fe+C饱和|ZrO2(MgO)|FeO(slag)+Cu(l)||钼丝,从CaO-SiO2-Al2O3-FeO系熔渣中分别得到了纯铁和无碳铁合金。

According to a new idea of the metallurgy with controlled oxygen flow, the unpolluted short circuit electrochemical reduction technique for molten oxide slags was developed. The electrochemical reduction principle of direct extraction of metal from molten oxide slags using oxygen ionic conductor as separate membrane was analysed. By means of equivalent circuit, oxygen ionic current characteristics in the open circuit mode and short circuit mode were compared; the effects on oxygen ionic current in electrochemical reduction process were discussed. The results show that oxygen ionic current may get large and the electrochemical reduction reaction rate will increase when the external circuit has a short circuit, total resistance of the circuit decreases, a stronger reducing agent was selected, the cathode-alloying is employed, and so on. In the present experiment the carbon saturated iron melt is used as the reducing agent and the following galvanic cells were assembled： graphite rod ｜[O]Fe-C saturated [ZrO2 （MgO） ｜FeO（slag）｜ iron rod, graphite rod ｜[O] Fe-C saturated ｜ZrO2（MgO）｜Cu（l）＋FeO（slag）｜ Mo wire. Pure iron and carbon-free ferroalloy were obtained respectively from CaO-SiO2-Al2O3-FeO molten slags by means of the above cells mentioned.