Overview of molybdenum applications
The application of molybdenum in the steel industry is the most important, accounting for about 80% of the total molybdenum consumption, followed by the chemical industry, accounting for about 10%. In addition, molybdenum is also used in electrical and electronic technology, medicine and agriculture, accounting for about 10% of the total consumption.
Alloy field
Molybdenum is consumed the most in the steel industry, mainly used to produce alloy steel (accounting for about 43% of molybdenum in the total steel consumption), stainless steel (about 23%), tool steel and high-speed steel (about 8%), cast iron and rolls (about 6%). Most of the molybdenum is directly used for steelmaking or cast iron after being pressed into industrial molybdenum oxide blocks, and a small part is first melted into molybdenum iron and then used for steelmaking. Molybdenum as an alloying element of steel has the following advantages: improve the strength and toughness of steel; improve the corrosion resistance of steel in acid and alkali solutions and liquid metals; improve the wear resistance of steel; improve the hardenability, weldability and heat resistance of steel. For example, stainless steel with a molybdenum content of 4%-5% is often used in places such as marine equipment and chemical equipment where erosion and corrosion are more serious.
Molybdenum copper alloy is applied in the aerospace field. Molybdenum is used as the matrix to add other elements (such as titanium, zirconium, hafnium, tungsten and rare earth elements, etc.) to form non-ferrous alloys. These alloying elements not only play a role in solid solution strengthening and maintaining low-temperature plasticity for molybdenum alloys, but also form a stable, dispersed carbide phase, thereby improving the strength and recrystallization temperature of the alloy. Molybdenum-based alloys are used in high-heating components, extrusion molds, glass melting furnace electrodes, spray coatings, metal processing tools, and spacecraft parts because of their good strength, mechanical stability, and high ductility.
Chemical Industry
Molybdenum grease lubricant: Molybdenum dioxide is a good solid lubricant because it has a low friction coefficient and high yield strength. It can be used normally in vacuum and various ultra-low and high temperature conditions. Therefore, it is widely used in gas turbines, gears, molds, aerospace, nuclear industry and other fields.
Catalyst: Molybdenum compounds are one of the most widely used catalysts and are widely used in chemical, petroleum, plastics, textile and other industries. For example: Molybdenum disulfide has anti-sulfur properties and can catalyze the hydrogenation of carbon monoxide to produce alcohols under certain conditions. It is a promising C1 chemical catalyst; Molybdenum is combined with cobalt and nickel as a catalyst for pretreatment of petroleum refining. Other common molybdenum-containing catalysts include: molybdenum disulfide, molybdenum oxide, molybdate, ammonium paramolybdate, etc.
Pigments: Chrome yellow and cadmium yellow are the most commonly used inorganic yellow pigments in the world today, but lead, chromium and cadmium are all toxic, while molybdenum yellow is not only non-toxic, but also has bright colors, good light and heat stability, so it is used in pigments and inks, plastics, rubber products and ceramics.
Flame retardant and smoke suppressant for organic polymers: Adding 3%-4% molybdenum trioxide to halogenated polyester can increase the critical oxygen index by 3%-4%, increase the amount of carbon generated during combustion by about 4%, and reduce the amount of smoke by 3%.
Corrosion inhibitor: Molybdate has very low toxicity and is weakly corrosive to organic additives added in corrosion inhibitors. It is often used in the construction of air conditioning cooling water and heating systems to prevent low-carbon steel from being corroded.
Electronic and electrical fields
Molybdenum wire for electric light sources has good conductivity and high temperature resistance, and its thermal expansion coefficient is similar to that of glass. It is widely used to manufacture core wires, lead wires, hooks and other components of spiral filaments. In addition, molybdenum wire is also an ideal electrode wire for electric spark wire cutting machine tools, which can cut various steels and cemented carbides. Its discharge machining is stable and can effectively improve the precision of molds.
Single-layer molybdenum sulfide material has good semiconductor properties, some of which exceed the widely used silicon and graphene, and is likely to become the next generation of semiconductor materials.
Medical field
Molybdenum is a trace element required by the human body. Molybdenum is one of the trace elements necessary for the human body and is also a component of many enzymes. Its main function in the body is to participate in the interaction between sulfur, iron and copper. An appropriate amount of molybdenum can promote human development, enhance the storage of oxygen in the body, inhibit tumors, maintain myocardial energy metabolism, and protect myocardium. Molybdenum deficiency can lead to dental caries, kidney stones, Keshan disease, osteomalacia, esophageal cancer and other diseases. Therefore, molybdenum is also used in medicine. For example, ammonium molybdate is mainly used for patients who rely on intravenous hypernutrition for a long time.
Animal Husbandry
The biological effect of molybdenum is mainly achieved by indirectly affecting the biological activity of enzymes as a component of certain molybdenum-containing enzymes in animals. In addition, molybdenum plays a special role in the nutritional metabolism of ruminants. On the one hand, molybdenum, as a component of nitrate oxidase of ruminant rumen microorganisms, directly participates in the conversion of feed nitrate in the rumen. On the other hand, molybdenum, as a cofactor of sulfate oxidase, has a stimulating effect on rumen microorganisms, which helps ruminants digest crude fiber substances and promotes the growth of ruminants. Therefore, when the molybdenum content in forage and feed is insufficient, it is necessary to add molybdenum additives to the feed in accordance with strict nutritional needs and process technology requirements to meet the needs of animals
Agricultural field
Comparison between normal sunflower plants (right) and molybdenum-deficient plants (left) Molybdenum is one of the essential “trace elements” in plants, and molybdenum deficiency will affect the normal growth of plants. As a trace element necessary for plant growth, molybdenum can not only promote the absorption of phosphorus by plants, but also accelerate the formation and conversion of alcohols in plants, increase the content of chlorophyll and vitamin C in plants, and improve the drought resistance, cold resistance and disease resistance of plants.