Direct Electrowinning of Titanium: Combination of Electrolysis and Melting of Titanium Metal by DC-ESR Apparatus

摘要

Electrode reactions in a direct-current electro-slag remelting (DC-ESR) process have been studied, and direct electrowinning of Ti by using a DC-ESR apparatus has been tried. The amount of non-metallic inclusion increased remarkably when a rod of Fe-Ni was remelted in CaF_2-CaO-Al_2O_3. The amount of inclusion depended on the slag composition, but did not depend on the polarity of the electrode. The result indicates that electrode reactions inevitably take place at the interfaces of the slag-consumable electrode and the -metal pool, and that the reactions are unsymmetrical. Titanium metal was deposited by using the DC-ESR apparatus, where a graphite rod was used as anode, a Fe or Cu base-plate was used as cathode and CaO-CaF_2-TiO_2 mixture as slag. The distance between the cathode and the anode was essential to the electrolysis. The current efficiency for the reduction was up to 18% with the proper distance between the electrodes.