Use of ferroalloyAs the steelmaking deoxidizer, the most widely used are silicomanganese, ferromanganese and ferrosilicon. Strong deoxidizers are aluminum (aluminum iron), silicon calcium, silicon zirconium, etc. (see the deoxidation reaction of steel). Commonly used as alloying additives are: ferromanganese, ferrochrome, ferrosilicon, ferro-iron, ferromolybdenum, ferrovanadium, ferrotitanium, nickel-iron, bismuth (iron), rare earth iron alloy, boron iron, phosphorus iron and the like. According to the steelmaking needs, various ferroalloys have many grades according to the alloying element content or the carbon content, and strictly limit the impurity content. An iron alloy containing two or more alloying elements is called a composite iron alloy. The use of such iron alloys can simultaneously add deoxidizing or alloying elements, which is advantageous for the steel making process, and can comprehensively utilize the symbiotic ore resources more economically and rationally. Commonly used are: manganese silicon, silicon calcium, silicon zirconium, silicon manganese aluminum, silicon manganese calcium and rare earth silicon iron.