Effect of Reaction Temperature on Silicon-Aluminum Alloy Prepared from Fly Ash

Abstract

Abstract The effect of carbothermal reduction of fly ash on the preparation of silicon and aluminium at different reaction temperatures was studied. XRD was used to analyze the phase of the reduction products at different reaction temperatures. The results showed that the products of carbothermal reduction fly ash included Al2O3, SiC, Al2SiO5, FeSiO3 and FeSi at 2073K. At 2123K, the products of carbon reduction fly ash were Al2O3, Al2SiO5, SiC, FeSi, Si and Al4.5FeSi. At 2173K, the main products of carbon reduction fly ash were Al2O3, Si, Al, SiC, FeSi and Al4.5FeSi. The diffraction peak intensity of silicon at 2173K was higher than that at 2123K, which indicated that increasing the reaction temperature was beneficial to the formation of silicon. Under the reaction conditions of 2223K and 2273K, the kinds of reduction products were the same, which were Al4.5FeSi, Si, Al, SiC and FeSi. The intensity of the diffraction peak of aluminium at 2273K was higher than that of aluminium at 2223K, which indicated that increasing the reaction temperature was beneficial to the formation of aluminium. In this experiment, with the increase of temperature, the degree of carbon reduction fly ash was more sufficient and 2273K was the optimum reaction temperature for preparing silicon-aluminium alloy from carbon reduction fly ash.