Hallmark rare metals Co. Ltd.

Molybdenum

Molybdenum mine of JDC, China

History

Molybdenum ores were confused with lead ores and graphite in ancient times. So the name Molybdenum is coming from the ancient greek word molybdos, meaning lead. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by the Swedish-German Chemist Carl Wilhelm Scheele. The metal was first isolated in 1781 by the Swedish chemist Peter Jacob Hjelm.

Properties

Molybdenum does not occur naturally as a free metal on Earth; it is found only in various oxidation states in minerals. The free element, a silvery metal with a gray cast, has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys.

Molybdenum is mined as a principal ore and is also recovered as a byproduct of copper and tungsten mining. China is the biggest producer of Molybdenum and the pere material has to be roasted, concentrated and reduced in several steps from the ore.

Most high-strength steel alloys (for example, 41xx steels) contain 0.25% to 8% molybdenum. Even in these small portions, more than 43,000 tonnes of molybdenum are used each year in stainless steels, tool steels, cast irons, and high-temperature superalloys.

Molybdenum can withstand extreme temperatures without significantly expanding or softening, making it useful in environments of intense heat, including military armor, aircraft parts, electrical contacts, industrial motors, and filaments.