Medium, low, and micro-carbon ferrochrome generally use silicon chromium alloy, chromite and lime as raw materials, refining and desilication in an electric furnace of 1500-6000 kVA, and high-basicity slag operation (CaO/SiO2 is 1.6-1.8). The low- and micro-carbon ferrochromium is also produced on a large scale by the heat conversion method. In production, two electric furnaces are used, one furnace smelting silicon-chromium alloy, and one furnace melting slag composed of ferrochromium and lime. The refining reaction is carried out in two barrels in two stages:
① After the slag from the slag furnace is injected into the first vat, the silicon-chromium alloy that has been initially desiliconized in the other vat is mixed in. Due to the large amount of slag oxidant, the desilication is sufficient, and the silicon content can be obtained below Micro carbon ferrochrome with 0.8% and low carbon content of 0.02%.
②The molten slag (containing Cr2O3 about 15%) in the first drum is moved to the second drum, and the silicon-chromium alloy (containing 45% silicon) smelted in the silicon-chromium electric furnace is heat-into the slag to react After that, a preliminary desiliconized silicon-chromium alloy (containing about 25% silicon) is obtained, which is transferred into the first vat to further desiliconize. The slag containing Cr2O3 is less than 2~3% and can be discarded.
