Explanation

Rare earth elements, also known as rare earth elements, are a collective term for 17 elements in the IIIB group of the periodic table, commonly represented by R or RE. The names and element symbols of rare earth metal are scandium Sc, yttrium Y, lanthanum U, cerium Ce, praseodymium Pr, neodymium Nd, promethium Pm, samarium Sm, europium Eu, gadolinium Gd, terbium Tb, dysprosium Dy, holmium Ho, erbium Er, thulium Tm, ytterbium Yb, lutetium Lu. Lanthanum, cerium, praseodymium, neodymium, lithium, samarium, and europium are usually referred to as light rare earths or cerium group rare earths, while gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and yttrium are referred to as heavy rare earths or yttrium group rare earths. It has strong chemical activity and can generate highly stable oxides by reacting with oxygen. Can react with water at different rates. React with halogens at high temperatures to generate halides. rare earth metal can also react with boron, carbon, sulfur, phosphorus, hydrogen and nitrogen to form corresponding compounds. Most of them are paramagnetism, and gadolinium, terbium, dysprosium, holmium and erbium are also ferromagnetism at low temperatures. There are significant differences in their physical properties, and the impurity content also has a significant impact on their performance. rare earth metal are mainly used in metallurgy, petrochemical industry, glass-ceramics and other fields. rare earth metal and their alloy play the role of deoxidation and desulfurization in steelmaking. They can refine grains, improve the processing performance of steel, and improve the strength, toughness, corrosion resistance and oxidation resistance of steel. Rare earth can change the graphite morphology in cast iron, improve the mechanical properties of cast iron, and be used as spheroidizing modifier in cast iron production. rare earth metal play the role of alloy and modification treatment on non-ferrous metal alloy. Rare earth additive and alloy elements can improve the strength, plasticity, heat resistance, corrosion resistance and conductivity of copper alloy, aluminum alloy and titanium alloy. Aluminum wires containing rare earths have high strength and corrosion resistance. Adding rare earth to Fe Cr Al alloy can improve oxidation resistance, resistivity and high temperature strength. Rare earth can refine titanium alloy grains and improve high temperature properties. Rare earth gasification products are widely used as catalysts for oil catalytic cracking, rubber synthesis and gas purification. Rare earth oxide is used for decolorization and coloring of glass, rare earth polishing powder is the grinding polishing materials of advanced optical glass, and rare earth is used in ceramics industry to manufacture glaze, refractory and ceramics materials. rare earth metal and their compounds have important applications in electronic industry and high-tech fields. Rare earth oxides are important luminescence materials for color TV.

Classification