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As a typical product of insoluble metal molybdenum (Mo), molybdenum bar is a rod with molybdenum as the main raw material, so in many cases we can also call it molybdenum rod or molybdenum rod, and the English name is molybdenum bar or molybdenum rod, with a purity of 99.7%, is widely used in smelting, power equipment and other fields because of its good thermal, mechanical, chemical, electrical and other properties.
In terms of physical and chemical properties, ordinary molybdenum bars have various advantages of metal molybdenum, such as bright and shiny surface, high melting point, high specific gravity, high strength, high hardness, low thermal expansion coefficient, high temperature resistance, good electrical and thermal conductivity, etc. Note: The molybdenum bar is silver in its natural color, and black when the surface retains the lubricant and oxide coating.
In terms of production methods, the preparation process of molybdenum bars is: molybdenum concentrate→oxidative roasting→calcine→leaching→ammonium molybdate solution→purification→neutralization crystallization→ammonium polymolybdate→dissolution→ammonium molybdate solution→evaporation Crystallization → ammonium paramolybdate → calcination → molybdenum trioxide → reduction → molybdenum powder → forming and sintering → molybdenum bar. Note that ammonia water needs to be added during leaching and dissolution; hydrochloric acid needs to be added during neutralization and crystallization; and the gas used during reduction is hydrogen.
In terms of appearance and shape, molybdenum strips are cuboid and cylindrical; in terms of surface state, molybdenum strips are alkali-washed, polished, polished and polished; in terms of use, molybdenum strips can be divided into Conventional molybdenum bar, high temperature molybdenum bar and steelmaking molybdenum bar.
Alkali-washed molybdenum bars refer to the rods that place ordinary molybdenum rods in a pot filled with lye for alkaline boiling and descaling. The surface is smooth and has a gray metallic luster. Lye is formulated with sodium hydroxide and sodium carbonate or trisodium phosphate. Polished molybdenum bar refers to the product of ordinary molybdenum bar after rough grinding, medium grinding and fine grinding. Turned molybdenum bar refers to the product of ordinary molybdenum bar after turning, although the surface is smooth and metallic luster, but rough, not as smooth as alkali washed and polished molybdenum bar. Polished molybdenum bar refers to the product of ordinary molybdenum bar after the surface roughness is reduced by mechanical, chemical or electrochemical methods, and the surface is bright and smooth.
Conventional molybdenum bars are mainly used to make molybdenum wires; high-temperature molybdenum bars can be used to prepare high-strength wire-cut molybdenum wires, high-temperature electric heating elements, electric light source materials, electric vacuum devices and high-temperature structural parts; steel-making molybdenum bars are mainly used as additives for steel. In order to improve the high temperature strength and toughness of steel.