Smelting medium and low carbon ferrochrome by high carbon ferrochrome refining
High carbon iron chromium refining method is divided into high carbon iron chromium with chromium ore refining and high carbon iron chromium with oxygen refining.
Refining high carbon ferro chromium with chromium ore: when refining high carbon ferro chromium with chromium ore, the refining slag has greater viscosity and higher melting point, and the smelting process temperature must be higher. Therefore, high power consumption, short lining life, carbon content is not easy to fall down. High carbon ferrochrome smelting with oxygen has great advantages, such as high productivity, low cost and high recovery rate. At present, the traditional production method or electrosilicon thermal method. Under the condition of making basic slag in electric furnace, the low carbon ferrochrome is produced by reducing the oxides of chromium and iron with the silicon in the silicon chromium alloy.
Low carbon ferrochrome in oxygen blowing: the equipment used in oxygen blowing to make low carbon ferrochrome is a converter, so it is called the converter method. According to different modes of oxygen supply, oxygen blowing can be divided into four types: side blowing, top blowing, bottom blowing and top and bottom compound blowing. The top - blown converter method is adopted in our country. The oxygen blowing method is to blow oxygen directly into the liquid high carbon ferrochrome to decarburize and produce low carbon ferrochrome. The main elements in high carbon iron chromium are chromium, iron, silicon, carbon, they can be oxidized. The main task of oxidation blowing high carbon iron chromium is to decarbonize and protect chromium. When oxygen is blown into liquid high-carbon ferrochrome, chromium and iron are oxidized first, since they make up more than 90% of the total amount of the alloy, and then these oxides oxidize the silicon in the alloy. Due to the oxidation of chromium, iron and silicon, the temperature of the molten pool increases rapidly and the decarburization reaction develops rapidly. The higher the temperature, the more conducive to the decarburization reaction and can inhibit the oxidation reaction of chromium, and the lower the carbon in the alloy can be reduced.
