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Tellurium is a grayish or silvery white, lustrous, crystalline, semimetallic element. It may exist in a hexagonal crystalline form or an amorphous powder.Soluble in sulfuric acid, nitric acid, potassium hydroxide, and potassium cyanide solutions; insoluble in water. Imparts garlic-like odor to breath, can be depilatory. It is a ptype semiconductor and its conductivity is sensitive to light exposure. It is found in sulfide ores and is produced as a by-product of copper or bismuth refining.

개요Tellurium is one of the rarest elements on earth similar to selenium, and was discovered in Transylvania in 1782 by Franz-Joseph Muller von Reichenstein. The name derived from the Latin word for earth. Tellurium is occasionally found naturally, more often as telluride of gold, calaverite.

출처Tellurium is the 71st most abundant element on Earth. It makes up a small portion ofigneous rocks and is sometimes found as a free element, but is more often recovered fromseveral ores. Its major ores are sylvanite (AgAuTe4), also known as graphic tellurium, calaverite,sylvanite, and krennerite, all with the same general formula (AuTe2). Other minor ores arenagyagite, black tellurium, hessite, altaite, and coloradoite. In addition, it is recovered fromgold telluride (AuTe2). Significant quantities are also recovered from the anode “slime” of theelectrolytic refining process of copper production.

용도Tellurium is a common constituent of ores that contain silver, gold, lead, antimony, and bismuth, and it is often present in small amounts in coal. Tellurium is widely used in metallurgy because it improves the properties of copper, tin, lead-based alloys, steel, and cast iron. It is used in rubber manufacturing to increase heat resistance and to retard the aging of rubber hoses and cable coatings. Small amounts are used in the electronics industry for lasers and photoreceptors. Tellurium is not an essential micronutrient; therefore, it is not found in nutritional supplements. As coloring agent in chinaware, porcelains, enamels, glass; reagent in producing black finish on silverware; in manufacture of special alloys of marked electrical resistance; in semiconductor research.

일반 설명Grayish-white, lustrous, brittle, crystalline solid; dark-gray to brown, amorphous powder with metallic characteristics. Used as a coloring agent in chinaware, porcelains, enamels, glass; producing black finish on silverware; semiconductor devices and research; manufacturing special alloys of marked electrical resistance. Improves mechanical properties of lead; powerful carbide stabilizer in cast iron, Tellurium vapor in "daylight" lamps, vulcanization of rubber. Blasting caps. Semiconductor research.

생산 방법Elemental tellurium (Te) has some metallic properties, although it is classed as a nonmetal or metalloid. The name is derived from the Latin word for earth, tellus. Tellurium is occasionally found naturally, more often as telluride of gold, calaverite. The elemental form has a bright luster, is brittle, readily powders, and burns slowly in air. Tellurium exists in two allotropic forms, in the form of powder and hexagonal crystalline (isomorphous) with gray selenium. The concentration in the earth’s crust is about 0.002 ppm. It is recovered from anode muds during the refining of blister copper. It is also found in various sulfide ores along with selenium and is produced as a by-product of metal refineries. The United States, Canada, Peru, and Japan are the largest producers. Tellurium’s industrial applications include its use as a metallurgical additive to improve the characteristics of alloys of copper, steel, lead, and bronze. Increased ductility results from its use in steel and copper alloys. Addition of tellurium to cast iron is used for chill control, and it is a basic part of blasting caps. It is used in some chemical processes as a catalyst for synthetic fiber production, and as a vulcanizing agent and accelerator in the processing of rubber.