Rare earth elements are a special kind of elements. In the periodic table, the elements with atomic Numbers from 57 to 71 are called rare earth elements. They are all lanthanide metals. And rare earth elements react with oxygen to form an oxide called a rare earth oxide. Rare earth elements are widely used in military manufacturing, petrochemicals, metallurgy, textiles, ceramics and other important manufacturing industries. With the rapid development of these manufacturing industries, rare earth elements and rare earth oxides will have more and more application value.
Rare earth oxides consist mainly of the following three substances, which are the three most common and commonly used rare earth oxides.
Lanthanum oxide
Formula for La₂O3, relative molecular mass of 325.84.
Physical properties: the appearance is white visible and amorphous powder material, the density size is approximately 6.51g/ cm3, larger than the average density of the earth itself, the melting point size is about 2217℃, the boiling point size is about 4200℃, and water solubility is low, is a kind of slightly soluble water substances.
Chemical properties: chemical properties are very active. It is soluble in acid and reacts with acid to form another kind of salt. If placed in air, it will react with water and carbon dioxide and slowly form lanthanum carbonate.
Application: mainly use lanthanum oxide for optical glass manufacturing, such as camera, microscope and other high precision instrument lens.
Cerium oxide
Common cerium oxide molecular formula of Ce2O3, CeO2, but there are a variety of cerium oxide between the two other formula of cerium oxide, and unstable, cerium oxide is a kind of molecular structure of hexagonal body oxide, studies have shown that it is about 2210 degrees Celsius, the melting point of the boiling point is about 3730 degrees Celsius, and because it is sensitive to air, and a variety of substances in the air, so in general to be sealed. Cerium dioxide is the most representative oxide of cerium. Studies have shown that it has a melting point of about 2,600 degrees Celsius, is insoluble in water, and does not readily react with sulfuric and nitric acids. Cerium oxide is often used as a catalyst in industry, while cerium oxide is widely used in semiconductor materials and automotive industries.
Praseodymium oxide
Like cerium oxide, praseodymium oxide also has a lot of different oxides with different molecular formula, among which, the most stable praseodymium oxide is praseodymium dioxide, the second one with good stability is PrO1.65, these two oxides are the molecular structure of the cube. Praseodymium oxide is widely used in the production and research of resistive materials, and it is also widely used in the manufacture and production of pigment.
Cerium oxide, praseodymium oxide and lanthanum oxide are the most common rare earth oxides. They will certainly be more widely used in the future.