PRODUCING ALUMINUM-SILICON ALLOYS FROM HIGH-ALUMINUM BEARING COAL FLY ASH BY CARBOTHERMAL REDUCTION METHOD

摘要

In this paper, the feasibility of producing aluminum-silicon alloys by carbothermal reduction of high-aluminum bearing coal fly ash is studied. The mixing ratio for a furnace charge was 60-80 percent coal fly ash; 20-40 percent bitumenite and petroleum coke as reducing agent. The mixing ratio of bitumenite and petroleum coke was in the range of 8:2-6:4; with 5-8 percent calcium lignosulphonate as binder. All these raw materials were mixed uniformly in the given proportions, briquetted and dried, then the carbothermal reduction experiments were conducted in a 1.25MVA mineral thermal furnace with temperature 1900-2100 deg C and time 4h. The aluminum-silicon alloys containing 50-55 percent aluminum and 40-45 percent silicon were obtained with recovery rates for aluminum in the range of 80-85 percent and for silicon in the range of 75-80 percent.