In 182 1, Berthier heats a mixture of charcoal, chromium oxide and iron oxide in a crucible to produce ferrochrome.
This method was used until 1857, when E.C.Fremy smelted Tasmanian ferrochrome ore in blast furnace to obtain Tasmanian pig iron containing 7% ~ 8% Cr.
During the period of 1870 ~ 1880, the ferrochromium produced by blast furnace contained 30% ~ 40% Cr, and C 10% ~ 20% Cr. Mu Wasang did a lot of work in smelting ferroalloy by electric furnace, and published in 1893 that the production of ferrochromium containing Cr 67 by electric furnace reduction.
It is a great progress to smelt high-carbon ferrochromium with electric furnace instead of blast furnace. 1886 audes e.g. odelstjerna describes the production of high-carbon ferrochromium containing 70% chromium by electric furnace in Sweden.
From 1906 to 1940, F.M.Becket and his collaborators carried out the process of reducing chromite with silicon to produce low-carbon ferrochrome. Experiments and production were carried out in 500kW single-phase double-electrode electric furnace (furnace output 400kg) to 12000kW three-phase electric furnace (furnace output 10t) to meet the needs of stainless steel production.
1920 or so, a three-step process for producing low-carbon ferrochromium has been formulated by Telechtan Ferroalloy Factory in Sweden. That is, silicothermic method, also known as Swedish method. 1939, R.Perrin obtained a patent to produce low-carbon ferrochrome by the reaction of liquid ferrochrome with chromite-lime melt. Commonly known as Pollan method, also known as heat exchange method. After continuous improvement, this method has become the main method to produce low-carbon ferrochromium.
1949, Ailas obtained the patent of producing C 0.0 1% low-carbon ferrochromium by vacuum solid decarbonization. Simplex ferrochromium is produced by Ma-rietta, an American union carbide company.