Question 2: What is molybdenum? Molybdenum is a chemical element with chemical symbol Mo and atomic number 42, and it is a gray transition metal. Pure metal molybdenum is silvery white and very hard. Adding a small amount of molybdenum to steel can harden it. Molybdenum is an important nutrient for plants and also exists in some enzymes. Molybdenum is hard and one of the refractory metal elements. In the fifth period of the periodic table, the symbol Mo, atomic number 42 and atomic weight 95.94, is a gray transition metal. The crustal abundance of molybdenum is 1. 1x 10-4%. About 20 kinds of molybdenum minerals have been discovered, and the molybdenum minerals with industrial value are mainly molybdenite (Mo Fan), followed by wolframite, iron-platinum ore, nonferrous molybdenite, platinum-copper ore and so on. The proven molybdenum reserves in the world are 26.8 million tons, with the United States ranking first in the world, followed by China and Chile. Molybdenum deposits in China are mainly distributed in Shaanxi, Liaoning and Henan provinces. China began to mine and beneficiate platinum ore from 1940, and successively built molybdenum smelting and staged iron production plants in 1950s.
Question 3: What is molybdenum in metal elements? Molybdenum is a metal element, which is usually used as an additive for alloy and stainless steel. It can enhance the strength, hardness, weldability and toughness of the alloy, and also enhance its high temperature resistance and corrosion resistance.
Chemical formula: (NH4) 2mo4o13.2h2o Molecular weight: 663.87.
Description: white crystalline powder
Question 4: What is molybdenum and what should I do? Molybdenum is an essential trace element for human body, animals and plants. It is silvery white metal, hard and tough. Molybdenum is contained in various tissues of human body, and the total amount in adults is 9mg, with the highest content in liver and kidney.
Molybdenum is mainly used in iron and steel industry, most of which is made of industrial molybdenum oxide and then directly used in steelmaking or cast iron, and a small part is smelted.
And then used for steelmaking. The molybdenum content in low alloy steel does not exceed 65438 0%, but the consumption in this respect accounts for about 50% of the total molybdenum consumption. Adding molybdenum to stainless steel can improve the corrosion resistance of steel. Adding molybdenum to cast iron can improve the strength and punishment resistance of iron. Nickel-based superalloy containing 18% molybdenum has the characteristics of high melting point, low density and small thermal expansion coefficient, and is used to manufacture various high-temperature components in aviation and aerospace. Molybdenum is widely used in electronic devices, such as electron tubes, transistors and rectifiers.
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Question 5: Where is molybdenum metal used? Where do people need to collect it? Molybdenum and its alloys are mainly used in alloy steel to improve the heat resistance and high-temperature strength of steel, and also used in heat-resistant steel (such as high-temperature pipes) and heat-resistant steel (such as gun materials). It is the raw material of steel works.
Question 6: What are the uses of metallic molybdenum? Molybdenum is a relatively late metal element, which was extracted from molybdenite by Swedish chemists in 1792. Molybdenum is widely used in industry because of its high strength, high melting point, corrosion resistance and wear resistance.
In metallurgical industry, molybdenum is used as an additive to produce various alloy steels, or to form advanced alloys with tungsten, nickel, cobalt, zirconium, titanium, vanadium and rhenium to improve its high-temperature strength, wear resistance and corrosion resistance. Molybdenum-containing alloy steel is used to manufacture transportation equipment, locomotives, industrial machinery and various instruments. Some stainless steels containing 4% ~ 5% molybdenum are used to produce precision chemical instruments and equipment used in seawater environment. High-speed steel containing 4% ~ 9.5% can be used to manufacture high-speed cutting tools. Alloys of molybdenum, nickel and chromium are used to make metal parts of aircraft, corrosion-resistant parts of locomotives and automobiles. Molybdenum and alloys of tungsten, chromium and vanadium are used to manufacture alloy parts and components of warships, tanks, cannons, rockets and satellites.
Molybdenum is widely used as heating material and structural material of high temperature electric furnace, large electrode and grid of vacuum tube, semiconductor and electric light source material. Molybdenum can also be used as a structural material for nuclear reactors because of its small thermal neutron capture cross section and high durability.
In chemical industry, molybdenum is mainly used as lubricant, catalyst and pigment. Because of its layered crystal structure and surface chemical properties, molybdenum disulfide has good lubricity at high temperature and high pressure, and is widely used as an additive for oils and fats. Molybdenum is a catalyst component in hydrodesulfurization and other petroleum refining processes, which is used for redox reactions of ethanol, formaldehyde and oil-based chemicals. Molybdenum orange is an important pigment. Molybdenum chemicals are widely used in dyes, inks, color precipitation dyes and anti-corrosion primers.
Molybdenum compounds are also widely used in agricultural fertilizers.
First, the characteristics of molybdenum raw materials
The elemental abundance of molybdenum in the crust is about 1× 10-6. Among magmatic rocks, the molybdenum content of granite is the highest, reaching 2× 10-6. In geochemical classification, molybdenum belongs to the carrier element of transition iron. In endogenous mineralization, molybdenum mainly combines with sulfur to form molybdenite.
Among more than 30 kinds of molybdenum-bearing minerals known in nature, molybdenum disulfide is the most widely distributed molybdenum ore with practical industrial value. Other common molybdenum-bearing minerals are molybdenite ([Fe3+(MoO4) 8? 8H2O]), calcium molybdate (CaMoO4), colored molybdenite (PbMoO4), molybdenite (MoS2), blue molybdenum (Mo3O8? NH2O), etc.
There are many types of molybdenite. Experiments show that the appearance of its polymorph is related to the formation temperature, and the formation temperature of 2H molybdenite is higher than that of 3R molybdenite. Amorphous MoS2→ colloidal MoS2→3MoS2→2HMoS2 is formed from low temperature to high temperature. The temperature measurement data show that the formation temperature range of molybdenite is very wide, from quite high temperature to relatively low temperature, and a large number of molybdenite is formed in the middle and high temperature stage. Under the action of hydrothermal solution, MoS2 precipitates under acidic conditions, that is, molybdenite is the most stable under acidic conditions. When the solution becomes neutral, molybdenum becomes soluble thiomolybdate and molybdate, and moves again. Under the conditions of low temperature and normal temperature, Mo4+ generates colloidal molybdenite (MoS2) in a strongly acidic reducing environment, and its oxidation product is blue molybdenite (Mo3O8? NH2O). Molybdenum is exogenous Mo6+ and has strong activity. Similar to uranium, it is stable in the neutral or alkaline transition environment of redox, from which a variety of molybdate minerals containing uranium are generated, such as molybdenite [(UO2)MoO4? 4H2O], molybdenite [Ca(UO2)3(MoO4)? (Oh) 2? 1 1H2O], etc. Fe Mo Hua [Fe2(MoO4)3？ NH2O] is a common mineral formed by sulfide ore under acidic conditions (pH = 3 ~ 5). Nonferrous molybdenite is the product of molybdenum-bearing lead-zinc ore under neutral conditions.
Rhenium and molybdenum have similar ionic radii, so they are often enriched in molybdenite instead of molybdenum and become the main source of industrial rhenium. The content of rhenium in molybdenite is often related to the content of 3R type in molybdenite and the content of rhenium in ore-forming solution.