Medium, low, and micro carbon ferrochrome generally uses silicon chromium alloy, chromite, and lime as raw materials, and is refined and desilicated using a 1500-6000 kVA electric furnace. High alkalinity slag operation is used (CaO/SiO2 is 1.6-1.8). Low and low-carbon ferrochrome is also produced on a large scale using the hot blending method. During production, two electric furnaces are used, one for smelting silicon chromium alloy and the other for melting slag composed of chromium ore and lime. The refining reaction is carried out in two stages in two drums: ① After the slag from the slag furnace is injected into the first drum, the silicon chromium alloy that has been preliminarily desilication in the other drum is mixed in. Due to the large excess amount of slag oxidant, desilication is sufficient, and micro carbon ferrochrome with silicon content below 0.8% and carbon content as low as 0.02% can be obtained. ② After the reaction in the first ladle, the slag (containing about 15% Cr2O3) is moved to the second ladle, and the silicon chromium alloy (containing 45% silicon) refined by the silicon chromium electric furnace is hot mixed into the slag. After the reaction, a preliminary desilication silicon chromium alloy (containing about 25% silicon) is obtained, which is further desilication in the first ladle. If the slag contains less than 2-3% Cr2O3, it can be discarded.
