Preparation of Al-Ti Master Alloy by Electrochemical Recovery of Titanium-Reducing Slag in Molten Salts

摘要

An electrochemical method for the preparation of an Al-Ti master alloy in Al electrolysis melts of Na~(3)AlF~(6)-Al~(2)O~(3)-LiF at 980°C was investigated. The Ti-reducing slag (5.24?wt.% Ti in the Ti-reducing slag) was obtained from the aluminothermic reduction of Na~(2)TiF~(6). The cold test (i.e., the aluminothermic reduction process without applying any voltages) result revealed the capability of the Al cathode to reduce the Ti slag, and the recovery rate could reach 45.8% at 980°C over 3.5?h with the addition of 10?wt.% Ti-reducing slag. In contrast, the recovery rate of Ti after electrolysis at 3.0?V could reach 99.2%. Thus, the electrochemical treatment for Ti-reducing slag is a cooperative process involving aluminothermic and electrochemical reduction reactions. Electrochemical analysis indicated that the Ti ions are reduced to metallic Ti according to Ti_(4+)?→?Ti_(3+)?→?Ti. An Al-Ti alloy layer could be prepared on the external surface of the Mo electrode after electrolysis with the addition of 12?wt.% Ti-reducing slag.