Views: 9 Author: Site Editor Publish Time: 2022-07-08 Origin: Site
The relationship between tungsten and molybdenum is that in the periodic table, they both belong to the VIB group and are in the sixth and fifth periods respectively. Tungsten (Tungsten), element symbol W, atomic number 74, atomic weight 183.84, atomic radius is about 139pm, melting point 3410°C, boiling point 5660°C; molybdenum (Molybdenum), element symbol Mo, atomic number 42, atomic weight 95.95, atomic radius About 139pm, melting point 2620°C, boiling point 5560°C.
Tungsten and molybdenum exist due to the phenomenon of "lanthanide shrinkage (the phenomenon in which the atomic radius and ionic radius of lanthanide elements gradually decrease with the increase of atomic number)", which affects the ionic radius of tungsten behind the lanthanide elements, and eventually As a result, both have similar ionic radii. Therefore, the relationship between W and Mo has more similar chemical properties than the general adjacent periodic elements of the same family, which are called similar elements.
Due to their similar properties, tungsten and molybdenum have an associated relationship, which is relatively common in mineral resources. In the process of extracting metallurgy, tungsten and molybdenum often have similar chemical behaviors and the same direction, making them difficult to remove impurities. element. Tungsten and molybdenum have significant differences in their affinity for oxygen and sulfur. Tungsten is an oxygen-loving element, which is commonly found in wolframite and scheelite, and tungsten-sulfurite is extremely rare. Molybdenum is a sulfur-philic element, which can occur in aqueous solutions. vulcanization reaction. Therefore, different forms of separation methods such as precipitation, solvent extraction, and ion exchange are currently being developed.
Tungsten is mainly used in the production of tungsten alloys, cemented carbides, etc., of which cemented carbides can be used to manufacture knives, drills and other products; molybdenum is not only an important additive in the steelmaking industry, but also a trace element that plants and animals cannot do without. Tungsten and molybdenum are both refractory metals and are representative of the refractory metal industry.
Tungsten and molybdenum alloys are produced by powder metallurgy with tungsten and molybdenum as the main raw materials. They have good thermal conductivity, excellent electrical conductivity, low thermal expansion coefficient, and strong corrosion resistance. They are widely used in electronics, Construction, aviation, military and other fields.