The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed...The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O]Fe+C saturation|ZrO2(MgO)|(FeO)(slag)|Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.展开更多
Kinetics of carbothermic reduction of manganese oxide and the catalyticeffect of La_2O_3 on the reduction have been studied by the measurement of mass loss in N_2atmosphere at different temperatures and followed by SE...Kinetics of carbothermic reduction of manganese oxide and the catalyticeffect of La_2O_3 on the reduction have been studied by the measurement of mass loss in N_2atmosphere at different temperatures and followed by SEM analysis. It is concluded that the kineticsof carbothermic reduction of manganese oxide is divided into three stages: gas diffusioncontrolling stage, carbon gasification con-trolling stage and solid state diffusion controllingstage. La_2O_3 has catalytic effect on the reduction. The catalytic effect of La_2O_3 increases withthe added amount of La_2O_3. SEM analysis shows that the catalytic mechanism is that La_2O_3promotes the transfer of oxygen ions so that carbon gasifying is catalyzed and thus carbothermicreduction of MnO_2 is catalyzed.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No.59934090) and the National Key Basic Research and Development Program of China (No.G1998061506)
文摘The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O]Fe+C saturation|ZrO2(MgO)|(FeO)(slag)|Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.
文摘Kinetics of carbothermic reduction of manganese oxide and the catalyticeffect of La_2O_3 on the reduction have been studied by the measurement of mass loss in N_2atmosphere at different temperatures and followed by SEM analysis. It is concluded that the kineticsof carbothermic reduction of manganese oxide is divided into three stages: gas diffusioncontrolling stage, carbon gasification con-trolling stage and solid state diffusion controllingstage. La_2O_3 has catalytic effect on the reduction. The catalytic effect of La_2O_3 increases withthe added amount of La_2O_3. SEM analysis shows that the catalytic mechanism is that La_2O_3promotes the transfer of oxygen ions so that carbon gasifying is catalyzed and thus carbothermicreduction of MnO_2 is catalyzed.
