Production of titanium powder directly from titanium dioxide (TiO_2) through an electronically mediated reaction (EMR) using calcium as a reductant was investigated. Feed material (TiO_2 powder or preform) and reductant (Ca-Ni alloy) were charged in electronically isolated locations in a molten calcium chloride (CaCl_2) salt at 1173 K. The current flow through an external circuit between the feed and reductant locations was monitored during the reduction of TiO_2. The electrochemical potential of the feed electrode was intermittently measured during the reduction experiment to analyze the reduction process. After the reduction experiment, pure titanium powder with low nickel content was obtained even though liquid Ca-Ni alloy was used as a reductant. These results demonstrate that titanium powder can be produced without direct physical contact between the feed and reductant. In certain experimental conditions, pure titanium powder with a purity of 99.5 mass% was successfully obtained.
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