Speaking of refractory metals, it is understood what metals fall under this definition.Vanadium, tungsten, molybdenum, niobium, rhenium, tantalum, zirconium and hafnium - metals whose melting temperature reaches 1650-1700 ° C.
in pure refractory metals are not found in nature.They are obtained from ore concentrates by a complex three-stage technology.The first step is to concentrate showdown, then there is the isolation and purification of chemical compounds and in custody - recovery and refining of metal.
sphere of use of refractory metals is wide.Refractory metals used in mechanical engineering, shipbuilding, electronics and chemical industries, because of their unique properties, namely their use as heat-resistant alloys materials.
consider each of refractory metals in particular.
Vanadium - solid metal steel-gray.The name of this metal was named after the goddess of beauty Vanadis, due to the color of the salts which are included in its composition.Vanadium is resistant to water and various acids.It is used in the manufacture of rubber, ceramics, glass, and, of course, steels.As a positive electrode used in batteries vanadium pentoxide.
Wolfram - gray hard metal under standard conditions can be described as the most refractory metal is used in metallurgy as a base.The name of the tungsten mineral wolframite received from (in the lane. With it. "Wolf foam"), who was known in the 15th century as tungsten hampered smelting tin.Wolfram finds its use in the manufacture of special boats used for growing single crystals, melting glass, etc..
Molybdenum - refractory metal silver-white color.Molybdenum hardly susceptible to oxidation and reaction with hydrogen occurs when molybdenum reaches the melting point (2620 ° C).Its use in the production of filaments for electric lamps, and for making electronic devices cathodes.
Niobium - light gray refractory metal, is easily treatable, resistant to corrosion.Included in the stainless steel, heat-resistant and corrosion-resistant alloys, improving their mechanical properties.
Rhenium among the most severe of refractory metals.The alloys of light-gray metal with tungsten and molybdenum fire resistant and used for the production of supersonic aircraft and missiles.
Tantalum - chemically resistant refractory metal light gray color with a purple hue.The steel is used as a component of corrosion-resistant, heat-resistant and hard alloys.
Pure zirconium a shiny metal that is easy to process both hot and cold worked.The distinguishing feature of the metal in that it has a very high resistance to corrosion.
Hafnium contained in zirconium ores.Metal with a silver sheen, used for the manufacture of absorbent cores of nuclear reactors.
