在不同电解时间和槽电压下，添加SiO2电解还原钛铁矿精矿制备钛铁合金. 结果表明，以添加一定量SiO2的钛铁矿精矿为阴极，控制阴极中主要组元的摩尔比Ti:Fe:Si=1.2:1:0.2，以石墨棒为阳极、CaCl2熔盐为电解质，在槽电压3.2 V、温度900℃下电解2 h，可制得疏松多孔、颗粒尺寸较均匀的FeTi合金粉体. 钛铁矿精电解还原过程中会生成CaTiO3和Fe?Ti?O等中间产物，添加的SiO2在电解时会优先还原生成单质Si，并参与CaTiO3等中间产物的还原反应，降低中间产物电解还原生成FeTi合金的理论电压，有利于加快电解还原钛铁矿精矿制备钛铁合金的速率.
The effect of SiO2 on preparation of ferrotitanium alloy from ilmenite concentrate by electroreduction in CaCl2 molten salt was investigated against electrolysis time and cell voltage. The results showed that the ferrotitanium alloy was prepared via electroreduction in CaCl2 molten salt at 900℃ with a cell voltage of 3.2 V for 2 h when the mixture of ilmenite concentrate and SiO2 with a molar ratio of Ti:Fe:Si=1.2:1:0.2 was served as cathode and the graphite rod as anode. The FeTi product prepared was porous in structure and uniform in particles size. The intermediates CaTiO3 and Fe?Ti?O were observed during the electroreduction of FeTiO3. The SiO2 added in the cathode was preferentially reduced to Si, which could in turn participate in the reduction of CaTiO3 and other intermediates. The theoretical potentials for the formation of FeTi alloy from the intermediates would be reduced. Therefore, addition of a suitable amount of SiO2 into the cathode could accelerate the electroreduction rate for the preparation of ferrotitanium from ilmenite concentrate.
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