Study on the Preparation of Si-Al Alloy by Carbon Reduction Coal Fly Ash

Abstract

In this paper, the effects of reduction temperature and carbon content on the preparation of silicon-aluminum alloy by carbothermal reduction coal fly ash were studied. The reduction products were characterized by XRD. The results showed that when carbon content was 1.15 or 1.3 times and reduction temperature was 1900°C, Al4C3 was formed in the reduction products and Al2O3 was not completely reacted; when carbon content was 1.15 times and reduction temperature was 2000°C, Al6Fe, SiC, Al8Fe2Si, Si and Al were produced by carbon reduction coal fly ash. When carbon content was 1.3 times and reduction temperature was 2000°C, reduction product had many impurities. When carbon content was 1.15 times and reduction temperature was 2000°C, siliconaluminum alloy was obtained, impurities of the reduction products were less, the effect of carbon reduction coal fly ash on the preparation of silicon-aluminum alloy was the best.

Phase Transformation of Alumina, Silica and Iron Oxide during Carbothermic Reduction of Fly Ash for Ceramics Production

“…When fly ash was reduced by carbon in air, Al-Si-Fe alloy was obtained at 2273 K [17]. Raw materials such as hematite [18] or iron [19] were added to reduce the initial reaction temperature of carbothermic reduction of fly ash.…”