Production of titanium powder directly from TiO2 in CaCl2 through an electronically mediated reaction (EMR)

Production of titanium powder directly from titanium dioxide (TiO2) through an electronically mediated reaction (EMR) using calcium as a reductant was investigated. Feed material (TiO2 powder or preform) and reductant (Ca-Ni alloy) were charged in electronically isolated locations in a molten calcium chloride (CaCl2) salt at 1173 K, and the current flow through an external circuit between the feed and reductant locations was monitored during reduction of TiO2. The voltage between feed electrode and reductant alloy was intermittently measured during the reduction experiment to monitor 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 metal powder can be produced without direct physical contact between the feed and reductant. In some experimental conditions, pure titanium powder with 99.5 mass% purity was successfully obtained.