Kolkrom järn

Smältning med elektrisk reduktionsugn, med koks som reduktionsmedel och kiseldioxid eller bauxit som flussmedel. Slaggsammansättningen är i allmänhet SiO227-33 procent, MgO3 0-34 procent, Al2O326-30 procent och Cr2O3<9.0%. Due to the formation of chromium carbide, the product contains 4-9% carbon. The reduction electric furnace for modern smelting of ferrochrome has a capacity of 10000~48000 KVA and is generally closed and fixed, with smelting power consumption of 3000~4000 Kilowatt-hour/t. The electric furnace for smelting silicon chromium alloy is similar to the chromium iron reduction electric furnace, and there are two smelting methods: one-step method and two-step method. The one-step smelting process uses Chromite, silica, coke and flux. The two-step method uses carbon ferrochromium, silica, and coke as raw materials for slag free smelting, and the smelting process is generally similar to that of ferrosilicon production. Smelting power consumption is about 3000~4000 Kilowatt-hour per ton.