Aluminum is a metallic element with symbol Al and atomic number 13. Its simple materials is a silvery white light metal. It has plasticity. Commodities are often made into bars, sheets, foils, powders, tapes and wires. An oxide film can be formed in humid air to prevent metal corrosion. Aluminum powder can burn violently when heated in air, and give off a dazzling white flame. Soluble in dilute sulfuric acid, nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solution, insoluble in water. The relative density is 2.70. The melting point is 660℃. The boiling point is 2327℃. The content of aluminum in the earth's crust is the third only to oxygen and silicon, and it is the most abundant metal element in the earth's crust. The development of three important industries, aviation, construction and automobile, requires that aluminum and its alloys have unique properties, which is of great benefit to the production and application of this new metal aluminum. It is widely used.
20 17,10127 October, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference. Aluminum products are in the list of carcinogens.
Content distribution:
The most abundant metal element in the crust is 8.3%. It mainly exists in aluminosilicate ores, as well as bauxite and cryolite. Alumina is a white amorphous powder with many variants, among which α-Al2O3 and β-Al2O3 are the most common. The corundum existing in nature belongs to α-Al2O3, which is second only to diamond in hardness, high melting point and acid and alkali resistance. It is usually used to make some bearings, abrasives and refractories. Such as corundum crucible, can withstand the high temperature of 1800℃. Al2O3 has many colors because it contains different impurities. For example, a trace of Cr(III) is red, which is called ruby; Sapphire containing Fe(II), Fe(III) or Ti(IV) is called sapphire.
Aluminum is a light metal with chemical symbol Al and atomic number 13. The content of aluminum in the earth's crust is second only to oxygen and silicon, ranking third. It is the most abundant metal element in the earth's crust, and its reserves rank second among metals. Among the metal varieties, it is the second largest metal after steel.