Direct Extraction of Titanium Alloys/Composites from Titanium Compounds Ores in Molten CaCl<sub>2</sub>

Abstract

Molten salt electroreduction process provides a simple approach for the facile production of alloys and composites. In this work, the solid oxide membrane (SOM)-assisted molten salt electroreduction process has been used to produce titanium alloys/composites directly from complex titanium compounds ores. The Ti-bearing blast-furnace slag, high titanium slag and natural ilmenite were used as raw materials. The SOM-assisted electroreduction process was carried out in molten calcium chloride (CaCl2) at 950-1000 degrees C and 3.8 V. The reaction mechanisms of the electroreduction process including the compounding process, the electroreduction process and the impurity-removal process were discussed. The results indicate that Ti5Si3, Ti5Si3/TiC, Ti5Si3/Ti3SiC2, Fe/TiC and TiAl3 alloys/composites can be directly electrosynthesized from different titanium compounds ores. CaTiO3 and Ca12Al14O33 compounds will be commonly generated as intermediate products during the electroreduction process in molten CaCl2. Impurities elements such as Ca and Mg can be removed during the electroreduction process. In addition, it is suggested that element Fe will be firstly generated during electroreduction process and thus can further improve the electronic conductivity of the ilmenite compounds pellets, Fe/TiC composites can be facilely produced from natural ilmenite.