Primary Molybdenum is a silvery-gray metal, and has particularly high values ​​of melting temperature, density, hardness, elastic modulus and electrical conductivity. State compact to air it oxidizes to form the trioxide only at high temperature, it is not attacked by dilute acids and caustic alkalis fused, and is also resistant to the attack of most molten metals.

The molybdenum, whose name derives from the greek and means similar to the lead, was identified in 1778 by CW Scheele in the mineral molybdenite, but was obtained in a state of high purity only in 1910. In nature, where there is free but in the compounds corresponding to its +4 and +6 oxidation states, is not an abundant element, because it is about 2 * 10-4% of the earth's crust. Its main mineral is molybdenite, MoS2.

The pure metallic molybdenum is used in the manufacture of glass-metal joints (for example, supports filament incandescent lamps), parts of electric furnaces in general and pieces of equipment operating at elevated temperatures and possibly in contact with molten metals. About 80% of molybdenum, however, is used as a component of ferrous alloys, in particular in the steel alloy addition of molybdenum increases hardness, corrosion resistance and abrasion resistance and toughness in hot. Molybdenum is also an indispensable component of special steels, stainless steels such as chromium-nickel steels used in the manufacture of high-speed tools and gas turbines for jet engines. Organic and inorganic compounds of molybdenum are used as catalysts for chemical and petrochemical processes, such as components of pigments and dyes for paints and ceramics, such as corrosion inhibitors and flame retardants, the molybdenum disulfide is used as a lubricant.

If you like this article, please press "Like" e "G+" to support us. Thank you!

Articoli che potrebbero interessarti:

Cadmium

Magnesium

Indium

Bismuth

Mercury