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What are the properties and applicatiosn of selenium?

wallpapers News 2021-11-15
What is Selenium?
Selenium powder, chemical formula Se, black gray nonmetal, soluble in concentrated sulfuric acid, chloroform, slightly soluble in carbon disulfide, toxic, insoluble in water, ethanol. Selenium powder is usually in the form of powder or granule, with pure appearance, consistent color, purity up to 99.99%, no soil and other impurities, stable composition, and even moisture. Selenium is a chemical element with the symbol Se and an atomic number of 34. It is a nonmetal (much less thought of as a nonmetal), somewhere between sulfur and tellurium on the periodic table, and also similar to arsenic. Selenium is found in metallic sulfide ores, where it partially displaces sulfur. Commercially, selenium is a by-product of the refining process of these ores, usually during the production process. Pure selenium or selenate compounds are known but are rare.
Selenium properties
Physical properties
Selenium is a red or gray powder, with a gray metallic luster quasi-metal. Of the six known solid allotrophs, three crystals (α monoitalic, β monoitalic, and gray triangulite) are the most important. The gray hexagonal crystal system is the most stable with a density of 4.81g/cm3. It also exists in three amorphous solid forms: two amorphous glassy forms of selenium, red and black. The former is brittle and has a density of 4.26g/cm3. The latter density is 4.28g/cm3, the other is colloidal selenium.
Selenium is brittle and toxic. It is soluble in carbon disulfide, benzene, quinoline. Selenium conducts electricity and its conductivity varies sharply with the intensity of light. It can produce semiconductors and photosensitive materials.
Melting point: 217℃.
Boiling point: 684.9℃.
Chemical properties
The first ionization energy of selenium is 9.752 electron volts. Selenium burns in the air with a blue flame, forming selenium dioxide (SeO2). Selenium reacts directly with hydrogen and halogens and directly combines with metals to form selenides. It does not react with non-oxidizing acids but is soluble in concentrated sulfuric acid, nitric acid, and strong bases. Selenium is oxidized to get selenium dioxide. Hydrogen selenide dissolved in water precipitates many heavy metal ions into particulate selenides.
Two selenides, namely normal selenide (M2Se) and acid selenide (MHSe), can be formed from selenium and metal with an oxidation state of +1. Aqueous solutions of positive alkali and alkaline earth metal selenides dissolve the element selenium to form a polyselenium compound (M2(Se) N), similar to the polysulfide formed by sulfur.
Selenium applications
Selenium can be used in different fields, depending on its purity. Selenium is now used in a wide variety of applications, from glass and metallurgy to pigments, agriculture, and electronics. Selenium powder is mainly used in the production of selenium dioxide as electrolytic manganese melting catalyst, other applications in rectifier, photographic exposure agent, petroleum working catalyst, copy toner cartridge, selenium photosensitive plate, alloy, feed and pigment in plastics, paint, enamel and glass, medical and health care medicine and other industries.
Selenium Supplier
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years of experience in providing super high-quality chemicals and Nanomaterials. Currently, our company has successfully developed a series of materials. Selenium produced by our company is of high purity and good quality. Send us an email or click on the needed products to send an inquiry.