Study of Carbothermal Reduction of Silica, Alumina and Titania Under Argon Gas

Abstract

Carbothermal reduction of light metals and semiconductor such as Al, Ti and Si under argon gas not only can reduce the reaction temperatures but can also minimize the formation of carbides and oxy-carbides intermediate compounds. The calculation of the gas phase diagram of Al-O-C, Ti-O-C and Si-O-C system suggests the possibility of the enhancement of the Al, Ti and Si product yield by the increase of the ratio of the partial pressure Al2O/CO, TiO/CO and SiO/CO. Thermodynamic considerations associated with this process are discussed along with the experimental results obtained over a wide range of parameters under argon gas using an induction heating furnace (IH) in a high temperature reactor. Powder mixtures were prepared of stoichiometric mixtures using powders either of alumina or silica or Titania with carbon. Experimental results obtained in induction furnace setup such as the pure element’s yields as a function of the CO partial pressure, PCO, temperatures range in the reaction zone of 1400–1800 °C and different deposition temperatures are presented. In this research work, we calculated the thermodynamic phase diagram with the partial pressure ratio of Al2O/CO, TiO/CO and SiO/CO. This diagrams suggests the possibility of enhancement of Al, Ti and Si yield by the increase of P(Al2O, TiO and SiO)/P(CO). At the optimal condition, the Al and Si yield was improved comparably to Ti which still under research.