Selenium is a nonmetal found mainly in sulfide ores. The estimated global distribution of consumption of selenium by application was metallurgy, 35%; glass manufacturing, 25%; agriculture, 10%; chemicals and pigments, 10%; electronics, 10%; and other, 10%. This represents a significant shift in the demand pattern; glass manufacturing was the leading end use for selenium for more than a decade. The main use for selenium in metallurgical end uses was for the production of electrolytic manganese in China where selenium dioxide (SeO2) was substituted for sulfur dioxide to reduce the power required to operate electrolytic cells.
In 2009, demand for selenium by electrolytic manganese metal producers in China decreased compared with that in 2008 owing to decreased consumption of electrolytic manganese metal by steel producers. About 2 kilograms of SeO2 were used per metric ton of electrolytic manganese metal produced.
Metallurgical-grade selenium was used as an additive to cast iron, copper, lead, and steel alloys to improve machinability and casting and forming properties. In the United States, selenium was used as an alloy with bismuth to substitute for lead in plumbing fixtures in response to requirements of the Safe Drinking Water Act Amendments of 1996 (Public Law 104–182) to reduce lead in potable water supplies. In lead-acid storage batteries, the addition of a small amount, about 0.02% by weight, of selenium to low-antimony lead alloys used in the support grids improves the casting and mechanical properties of the alloy.
Selenium was used to decolorize the green tint caused by iron impurities in container glass and other soda-lime silica glass. It was also used as a colorant in art and other glass, such as that used in traffic lights, and in architectural plate and automobile glass to reduce solar heat transmission through the glass. Selenium, an essential micronutrient for animal and human health, was added to fertilizer used to grow crops for animal and human consumption. This practice was more common outside the United States, in countries with selenium-poor soils, such as Australia and China.
Chemical and pigment uses of selenium include industrial and pharmaceutical applications. Selenium's principal pharmaceutical use was in shampoo to control dandruff and dermatitis and as an antifungal agent. Cadmium sulfoselenide compounds were used as pigments in ceramics, glazes, paints, and plastics, but because of the relatively high cost and the toxicity of cadmium-based pigments, their use was generally restricted to applications where they were uniquely suited. Additionally, selenium was used in catalysts to enhance selective oxidation in plating solutions to improve appearance and durability, in blasting caps and gun bluing, in digital x-ray detectors, and in zinc selenide for infrared windows in carbon dioxide lasers.
Price: The Platts Metals Week annual average New York dealer price for selenium was $23.07 per pound in 2009 and was 26% lower than the annual average price in 2008. The price remained about $20 per pound for the first 7 months of 2009, down from the yearend 2008 price of $23 per pound. Some analysts thought that after peaking at more than $40 per pound in March 2008, the downward-trending price was caused by an oversupply that developed in 2008 because of decreased demand and continued into the first half of 2009. The price rose in August because of increased demand from glass and ceramics production in India and electrolytic manganese metal production in China and finished the year at $29 per pound.
Foreign Trade: Exports of selenium materials in 2009 increased by 13% compared with those of 2008. In descending order, Hong Kong, China, Australia, Germany, the Republic of Korea, and Sweden accounted for 88% of selenium exports in 2009. In 2009, imports of selenium (SeO2 and selenium unwrought and waste and scrap) decreased by 49% to 263 t, compared with 2008 imports. Germany, Canada, Mexico, Belgium, the Philippines, Japan, China, and the United Kingdom, in descending order, accounted for 99% of the imports of selenium metal and SeO2 into the United States in 2009.
In 2009, China was the leading consumer and a significant producer of selenium. China still depended, however, on imports for most of its selenium needs and imported 1,400 t of selenium products in 2008, a 3% increase compared with 2008 imports. China's consumption was estimated to be 1,500 to 2,000 t/yr, with electrolytic manganese production consuming about 1,000 t/yr and ceramics and glassmaking consuming 350 t/yr. In 2009, the country had about 400 t/yr of refined selenium capacity, but this was expected to increase to 600 t/yr of selenium when new production techniques are implemented. Japanese selenium production was estimated to be 780 t, an increase of 3% compared with that of 2008. Stocks of selenium in Japan decreased to 116 t, a 27% decline compared with stocks at the end of 2008
Events, Trends, and Issues: The supply of selenium is directly affected by the supply of the materials from which it is a byproduct—copper, and to a lesser extent, nickel. Estimated domestic selenium production was unchanged in 2010 compared with that of 2009.
Domestic use of selenium in glass and in copiers in 2010 continued to decline. The use of selenium as a substitute for lead in free-machining brasses also was slightly higher owing to the improvements in the global economic conditions. The use of selenium in fertilizers and supplements in the plant-animal-human food chain and as human vitamin supplements increased as its health benefits were documented. Although small amounts of selenium are considered beneficial, it can be hazardous in larger quantities. Continued increased interest in solar cell technologies has increased the consumption of selenium in CIGS solar cells.
World Resources: Reserves for selenium are based on identified copper deposits. Coal generally contains between 0.5 and 12 parts per million of selenium, or about 80 to 90 times the average for copper deposits. The recovery of selenium from coal, although technically feasible, does not appear likely in the foreseeable future.
Substitutes: High-purity silicon has replaced selenium in high-voltage rectifiers. Silicon is also the major substitute for selenium in low- and medium-voltage rectifiers and solar photovoltaic cells. Organic pigments have been developed as substitutes for cadmium sulfoselenide pigments. Other substitutes include cerium oxide as either a colorant or decolorant in glass; tellurium in pigments and rubber; bismuth, lead, and tellurium in free-machining alloys; and bismuth and tellurium in lead-free brasses. Sulfur dioxide can be used as a replacement for selenium dioxide in the production of electrolytic manganese metal.
The selenium-tellurium photoreceptors used in some xerographic copiers and laser printers have been replaced by organic photoreceptors in newer machines. Amorphous silicon and cadmium telluride are the two principal competitors to copper indium diselenide in thin-film photovoltaic power cells.
Selenium Producers 5N Plus (TSX: VNP) - http://www.5nplus.com/ - selenium shots
ASARCO - http://www.asarco.com/seltel_selenium_T.html Huludao Zinc Industry Co. (SHE: 000751) - Selenium products
II-VI (NASDAQ: IIVI) - http://www.prsmetals.com/ - Their Pacific Rare Specialty Metals & Chemicals subsidiary produces selenium and tellurium Jiangxi Copper Company (OTC: JIXAY) ESPI High Purity Metals - http://www.espimetals.com/metals/catselenium.htm KGHM Polska Miedz - The Polish copper producer produced selenium at its precious metal plant at the Glogow smelter from anode slimes generated at its Glogow and Legnica copper refineries
Kyshtymsky Electrolyte Copper
Norilsk Nickel (OTC: NILSY) - http://www.nornik.ru/en/production/product_type/pt26/ Shinko Chemical - High purity selenium production
Southern Copper Corp - La Caridad precious metals plant in Sonora, Mexico had a 2009 capacity of 342 kilograms per day of selenium. Southern Copper also produced selenium at its Ilo refinery in the southern part of Peru. In 2009, selenium production was 56,000 kilograms, up by 27% compared with that of 2008.