U.S.Geological Survey (USGS): Silicon

Statistics and Information: Silicon (Si) is a light chemical element that combines with oxygen and other elements to form silicates. Silicon in the form of silicates constitutes more than 25% of the Earth's crust. Silica (SiO₂)as quartz or quartzite is used to produce silicon ferroalloys and silicon metal. Demand for silicon ferroalloys is driven principally by the production of cast iron and steel. Silicon metal, which generally is produced like ferrosilicon in submerged-arc electric furnaces, is used not as a ferroalloy, but rather for alloying with aluminum and for production of chemicals, especially silicones. Small quantities of silicon are processed into high-purity silicon for use in the semiconductor industry.

Silicon
(Data in thousand metric tons of silicon content unless otherwise noted)

U.S. Domestic Production and Use: Estimated value of silicon metal and alloys (excluding semiconductor-grade silicon) produced in the United States in 2008 was about $87 billion. Four companies produced silicon materials in six plants. Of those companies, three produced ferrosilicon in four plants. Silicon metal was produced by two companies in four plants. Two of the four companies in the industry produced both products at two plants. All of the ferrosilicon and silicon metal plants were east of the Mississippi River. Most ferrosilicon was consumed in the ferrous foundry and steel industries, predominantly in the eastern part of the United States. The main consumers of silicon metal were producers of aluminum and aluminum alloys and the chemical industry. The semiconductor industry, which manufactures chips for computers from high-purity silicon, accounted for only a small percentage of silicon demand.

U.S. Recycling: Insignificant.

U.S. Import Sources (2004-07): Ferrosilicon: China, 42%; Russia, 18%; Venezuela, 17%; Canada, 8%; and other, 15%. Silicon metal: Brazil, 38%; South Africa, 25%; Canada, 17%; Norway, 6%; and other, 14%. Total: China, 24%; Brazil, 18%; Canada, 12%, South Africa, 11%; and other, 35%.

U.S. Tariff:

U.S. Depletion Allowance: Quartzite, 14% (Domestic and foreign); gravel, 5% (Domestic and foreign).

Events, Trends, and Issues: U.S. domestic ferrosilicon production in 2008, expressed in terms of contained silicon, was expected to increase by 7% from that of 2007. Through the first 8 months of 2008, spot market prices trended upward in the U.S. market for silicon materials, owing to increased demand for ferrosilicon in steelmaking, increased Chinese ferrosilicon export prices, increased demand for silicon metal production, and decreased silicon metal imports from Brazil and South Africa the largest foreign suppliers of silicon metal to the United States. However, U.S. spot market prices for silicon materials declined in September and October, primarily because of decreasing demand caused by global financial problems that began during the third quarter of 2008.

Demand for silicon metal comes primarily from the aluminum and chemical industries. U.S. domestic secondary aluminum production the primary materials source for aluminum-silicon alloys was projected to decrease by 13% in 2008. In the first 7 months of 2008, United States chemical production was nearly unchanged compared with that in 2007. U.S. domestic apparent consumption of ferrosilicon in 2008 was projected to increase by 4% compared with that of 2007. The annual growth rate for ferrosilicon demand usually falls in the range of 1% to 2%, in line with long-term trends in steel production, and through the first nine months of 2008, U.S. domestic steel production was 4% higher than that of the same period in 2007.

Two major developments affected the global supply of silicon materials. Production of silicon materials in Norway increased to an estimated 340,000 tons in 2008 from 221,000 tons in 2007, owing primarily to high ferrosilicon production levels. This was offset somewhat by the significant decrease (22%) in Ukraine’s ferrosilicon and silicon metal production compared with that of 2007.

World Mine Production, Reserves, and Reserve Base:

Ferrosilicon accounts for about four-fifths of world silicon production (gross-weight basis). The leading countries for ferrosilicon production, in descending order of production, were China, Russia, Norway, the United States, and South Africa, and for silicon metal, China, Brazil, France, and Norway. China was by far the leading producer of both ferrosilicon (2,700,000 tons) and silicon metal (560,000 tons) in 2008.

World Resources: World and U.S. domestic resources for making silicon metal and alloys are abundant and, in most producing countries, adequate to supply world requirements for many decades. The source of the silicon is silica in various natural forms, such as quartzite.

Substitutes: Aluminum, silicon carbide, and silicomanganese can be substituted for ferrosilicon in some applications. Gallium arsenide and germanium are the principal substitutes for silicon in semiconductor and infrared applications.

(e) Estimated.
(W) Withheld to avoid disclosing company proprietary data.
(1) Production quantities are combined totals of estimated silicon content for ferrosilicon and silicon metal, as applicable, except as noted.
(2) Ferrosilicon only.

U.S. Geological Survey, Mineral Commodity Summaries, January 2009