Micro-carbon ferrochromium is mainly used in the production of stainless steel, acid-resistant steel and heat-resistant steel. The smelting methods include electric silicothermal method and thermal conversion method.
Smelting method: Smelting micro-carbon ferrochrome by electrosilicon thermal method is to add chromium ore, silicon-chromium alloy and lime into the electric arc furnace, mainly rely on electric heat to melt the charge, and silicon in the silicon-chromium alloy reduces Cr203 in the chromium ore. .
Electrosilicothermal method: The equipment used to smelt micro-carbon ferrochrome is an electric arc furnace. It is divided into two types: open and covered, the power is mostly below 500kV.A, and it is equipped with a device to adjust the voltage on load to meet the needs of different operating periods. The furnace lining is built with magnesia bricks and graphite electrodes are used. The main raw materials for smelting micro-carbon ferrochrome by electrosilicothermal method are chromium ore, silicon-chromium alloy and lime. Some are also added with fluorite and iron scales. Chromium ore should be dry, clean lump ore or concentrate, with a lump size of less than 50mm; containing Cr203>40%, Cr203/2Fe0>2.0, and phosphorus content should not exceed 0.03%. Choose silicon-chromium alloys with different carbon contents according to the brand of micro-carbon ferrochrome to be smelted.
The process of smelting micro-carbon ferrochrome by hot mixing method is to heat the pre-melted chromium ore-lime melt and silicon-chromium alloy in the ladle outside the furnace to produce micro-carbon ferrochrome. According to the times of staged reduction of Cr2O3 in the slag, the heat exchange process can be divided into one-step heat exchange method, two-step heat exchange method and three-step heat exchange method.