What is the function of rare earth?

On the military side

Rare earth is called "gold" in industry. Because of its excellent physical properties such as optoelectromagnetism, it can be combined with other materials to form new materials with different properties. Its most significant function is to greatly improve the quality and performance of other products. For example, the tactical performance of steel, aluminum alloy, magnesium alloy and titanium alloy used to manufacture tanks, planes and missiles will be greatly improved. Moreover, rare earth is also a lubricant for electronics, lasers, nuclear industry, superconductivity and many other high technologies. Once rare earth technology is used in the military, it will inevitably bring about a leap in military technology. In a sense, the overwhelming control of the US military in several local wars after the Cold War and its ability to openly kill the enemy without scruple stem from its advantages in the field of rare earth science and technology.

In the metallurgical industry

Adding rare earth metals, fluorides and silicides to steel can play the role of refining, desulfurization and neutralization of harmful impurities with low melting point, and can improve the machinability of steel; Rare-earth ferrosilicon alloy and rare-earth ferrosilicon magnesium alloy are used as nodulizers to produce rare-earth nodular cast iron, which are widely used in machinery manufacturing industries such as automobiles, tractors and diesel engines because they are particularly suitable for producing complex nodular cast iron with special requirements. Adding rare earth metals to non-ferrous alloys such as magnesium, aluminum, copper, zinc and nickel can improve the physical and chemical properties of the alloy and improve its mechanical properties at room temperature and high temperature.

In the petrochemical industry

Rare earth molecular sieve catalyst has the advantages of high activity, good selectivity and strong resistance to heavy metal poisoning, and it can replace aluminum silicate catalyst in the process of petroleum catalytic cracking. In the process of synthetic ammonia production, a small amount of rare earth nitrate is used as cocatalyst, and its gas treatment capacity is 1.5 times that of nickel-aluminum catalyst; In the process of synthesizing cis-polybutadiene rubber and isoprene rubber, rare earth naphthenate-triisobutyl aluminum catalyst is used, and the obtained products have the advantages of excellent performance, less equipment adhesion, stable operation and short post-treatment process. Composite rare earth oxides can also be used as catalysts for purifying the exhaust gas of internal combustion engines, and cerium naphthenate can also be used as paint drier.

In terms of glass ceramics

Rare earth oxide or processed rare earth concentrate can be widely used as polishing powder for polishing optical glass, spectacle lens, kinescope, oscilloscope tube, flat glass, plastic and metal tableware; In the process of melting glass, the strong oxidation of cerium dioxide to iron can be used to reduce the iron content in glass, so as to achieve the purpose of removing green from glass; Adding rare earth oxides can make optical glass and special glass with different uses, including glass that can pass infrared rays and absorb ultraviolet rays, glass that is acid-resistant and heat-resistant, and glass that can prevent X rays. Adding rare earth to ceramic glaze and porcelain glaze can reduce the fragmentation of glaze and make products show different colors, which is widely used in ceramic industry.

In terms of new materials

Rare earth cobalt NdFeB permanent magnet materials have high remanence, high coercivity and high magnetic energy product, which are widely used in electronics and aerospace industries. Garnet ferrite single crystals and polycrystals composed of pure rare earth oxides and iron oxides can be used in microwave and electronic industries. Neodymium glass made of yttrium aluminum garnet and high purity neodymium oxide can be used as solid laser materials; Rare earth hexaboride can be used to make cathode materials for electron emission; La-Ni metal is a newly developed hydrogen storage material in 1970s. Lanthanum chromate is a high temperature thermoelectric material; In recent years, superconducting materials made of barium-based oxides modified by barium, yttrium, copper and oxygen can obtain superconductors in liquid nitrogen temperature region, which makes a breakthrough in the research and development of superconducting materials. In addition, rare earths are also widely used in lighting sources, projection TV phosphors, intensifying screen phosphors, tricolor phosphors and copy lamp powders; In agriculture, applying a small amount of rare earth nitrate to field crops can increase the yield by 5 ~10%; In textile industry, rare earth chloride is also widely used in tanning fur, fur dyeing, wool dyeing and carpet dyeing.