Ferrochrome, or ferrochromium (FeCr) is a type of ferroalloy, that is, an alloy of chromium and

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

, generally containing 50 to 70% chromium by weight. Ferrochrome is produced by electric arc carbothermic reduction of chromite. Most of the global output is produced in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

and

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, which have large domestic chromite resources. Increasing amounts are coming from Russia and China. Production of steel, especially that of stainless steel with chromium content of 10 to 20%, is the largest consumer and the main application of ferrochrome.

Usage

Over 80% of the world's ferrochrome is utilised in the production of stainless steel. In 2006, 28,000,000 tons of stainless steel were produced. Stainless steel depends on chromium for its appearance and resistance to corrosion. Average chrome content in stainless steel is approx. 18%. It is also used to add chromium to carbon steel. FeCr from South Africa, known as "charge chrome" and produced from a Cr containing ore with a low carbon content, is most commonly used in stainless steel production. Alternatively, high carbon FeCr produced from high-grade ore found in Kazakhstan (among other places) is more commonly used in specialist applications such as engineering steels where a high Cr/Fe ratio and minimum levels of other elements ( sulfur,

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

titanium Titanium is a chemical element with the Symbol (chemistry), symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resista ...

etc.) are important and production of finished metals takes place in small electric arc furnaces compared to large scale blast furnaces.

Production

Ferrochrome production is essentially a

carbothermic reduction Carbothermic reactions involve the reduction of substances, often metal oxides (O^2-), using carbon as the reducing agent. These chemical reactions are usually conducted at temperatures of several hundred degrees Celsius. Such processes are applie ...

operation taking place at high temperatures. Chromite (an oxide of Cr and Fe) is reduced by coal and coke to form the iron-chromium alloy. The heat for this reaction can come from several forms, but typically from the

electric arc An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma; the plasma may produce visible light. An ...

formed between the tips of electrodes in the bottom of the furnace and the furnace hearth. This arc creates temperatures of about . In the process of smelting, huge amounts of electricity are consumed, making production very expensive in countries where power costs are high. Tapping of the material from the furnace takes place intermittently. When enough smelted ferrochrome has accumulated in the furnace hearth, the tap hole is drilled open and a stream of molten metal and slag rushes down a trough into a chill or ladle. Ferrochrome solidifies in large

casting Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a ''casting'', which is ejected ...

s which are crushed for sale or further processed. Ferrochrome is generally classified by the amount of carbon and chrome it contains. Vast majority of FeCr produced is "charge chrome" from South Africa, with high carbon being the second largest segment followed by the smaller sectors of low carbon and intermediate carbon material.

Trading

In March 2021, the Shanghai Futures Exchange decided that it would list at some unknown date ferrochrome futures. At the time, ferrochrome spot 6-8% C, basis 50% Cr, ddp China was trading at $1,336-1,382. In January 2021 the spot price had been 25% lower.

References

{{Reflist Chromium alloys Ferroalloys