Preparation of Aluminium-Silicon Alloys by Aluminothermic Reduction

Abstract

Alloys of aluminium-silicon have today attained considerable commercial importance in their wide use for multifarious applications and as much as 80 per cent of the world's production of light alloy castings have been estimated to belong to the family of these alloys. Based on thermodynamical data , the reduction of silica by aluminium is feasible . It was observed that substantial reduction of quartz depends upon a number of factors, the chief of which are; particle size of quartz, amount of cryolite in the charge, temperature of the reactants and holding time.Physical properties of the alloys made by this method have been compared with the physical properties of corresponding alloys produced by direct alloying of the two metals. This comparison yielded identical results in the two cases. It has finally been stressed that this method can be usefully exploited for commercial applications in countries dependent on silicon imports and rich in bauxite and quartz such as India.