Name: Magnesium oxide

Commonly known as: bitter soil; lamp powder; calcined soil

Chemical formula: MgO

Relative molecular mass: 40.3044

CAS NO .: 1309-48-4 EINECS number: 215-171-9

Physical and chemical properties

Density 3.58g / ml

Melting point 2852 ° C

Boiling point 3600 ° C

Water soluble 6.2 mg / L (20 ° C), reacts

Physical properties, white easy powder, odorless, tasteless, this product is insoluble in water and ethanol, melting point 2852 ℃, boiling point 3600 ℃, magnesium oxide (lightly burned powder) has a high fire resistance insulation performance. It can be transformed into crystals after being burned at a high temperature above 1000 ℃, and it will become dead burned magnesium oxide (light burned powder) or sintered magnesium oxide (light burned powder) when it is raised above 1500 ° C. The research on the surface area of magnesium oxide (light burnt powder) is very important. The detection data of the surface area of magnesium oxide (light burnt powder) is only reliable when the result is detected by the BET method. Detection has now been eliminated in China. At present, the multi-point BET method is used uniformly for the specific surface area testing at home and abroad. The specific surface area measurement standards developed at home and abroad are based on the BET test method. Please refer to China's national standard (GB / T 19587-2004)-Gas adsorption BET principle Method for determining the specific surface area of solid materials. The measurement of specific surface area is actually a time-consuming task. Due to the different adsorption capacity of samples, the testing of some samples may take a whole day. If the test process is not fully automated, then the tester ca n’t leave at all times. A high degree of concentration, observing the instrument panel, manipulating the knob, and a little inattention will lead to the failure of the test process, which will waste a lot of precious time of the tester. The F-Sorb 2400 specific surface area analyzer is an instrument that can truly realize the detection function of the BET method (both with direct comparison method), and the more important F-Sorb 2400 specific surface area analyzer is the only fully automated intelligent specific surface area detection device in China The test results are highly consistent with international standards, and the stability is also very good. At the same time, it reduces human errors and improves the accuracy of test results.

Chemical properties: Magnesium oxide (light burned powder) is an alkaline oxide, which has the generality of alkaline oxide

When exposed to air, it easily absorbs water and carbon dioxide and gradually becomes basic magnesium carbonate. Lighter products are faster than heavier products. They combine with water to produce magnesium hydroxide (lightly burned powder), which is slightly alkaline reaction and saturated aqueous solution. The pH is 10.3. Soluble in acid and ammonium salt is difficult to dissolve in water, the solution is alkaline. Insoluble in ethanol.

MgO + 2HCl → MgCl2 + H2O

MgO + NH4Cl → MgCl2 + NH3 ↑ + 2H2O

Slowly react with water to produce magnesium hydroxide (light burnt powder)

It has strong refraction in the visible and near ultraviolet range.

Classification: divided into light magnesium oxide (light burned powder) and heavy magnesium oxide (light burned powder). Lightweight and fluffy, white amorphous powder. Odorless, tasteless and non-toxic. Density 3.58g / cm3. It is difficult to dissolve in pure water and organic solvents, and the solubility in water increases due to the presence of carbon dioxide. Soluble in acid and ammonium salt solution. Transformed into crystals by high temperature burning. In case of carbon dioxide in the air, magnesium carbonate double salt is formed. The heavy mass is compact and is white or beige powder. Easy to combine with water, easily absorb moisture and carbon dioxide in exposed air. Mixing with magnesium chloride solution is easy to gel and harden.

Applications: Determination of sulfur and pyrite in coal and sulfur and arsenic in steel Used as a standard for white pigments. Light magnesium oxide (light burned powder) is mainly used as a raw material for preparing ceramics, enamel, refractory crucibles and refractory bricks. It is also used as a filler for polishing agents, urls, coatings and paper, as a promoter and activator for neoprene and fluoroelastomers. After mixing with magnesium chloride and other solutions, it can be made into magnesium oxide (light burned powder). It is used as antacid and laxative in medicine. It is used for gastric ulcer caused by hyperacidity and duodenum. In the chemical industry, it is used as a catalyst and a raw material for manufacturing magnesium salts. It is also used in the manufacture of glass, dyed meal, phenolic plastics, etc. Heavy magnesium oxide (light burned powder) is used in the firing mill and semi-roller in the rice milling industry. The construction industry is used to manufacture artificial chemical floors, artificial marble, heat insulation boards, sound insulation boards, and the plastic industry is used as a filler. It can also be used to produce other magnesium salts.

Mainly used to formulate internal medicine to neutralize excessive stomach acid. Commonly used preparations are: magnesium emulsion-emulsion; magnesium cover sheet-each containing 0.1g of MgO ;; acid powder-powder made of magnesium oxide (light burned powder) and sodium bicarbonate.