Discover the history
The word aluminium is derived from the Roman alumen (alum). In 1746 German scientist Porter (JHPott) made alumina from alum. In 1807, the Englishman H. Davy tried to electrolyze fused alumina to obtain metal. In the following year, Davy gave the envisioned metal the name alumium and later changed to aluminum. In 1825, Danish scientist H Coersted reduced anhydrous aluminum chloride with potassium amalgam to obtain several milligrams of metallic aluminum. In 1827, German scientist Waller (F.Wohler) used potassium to reduce alumina to obtain a small amount of metallic aluminum. In 1854, the French scientist, SC Deville, used sodium to reduce NaAlCl4 complex salt to produce aluminum. He also built factories to produce helmets, cutlery and toys. The price is high and it is equivalent to gold. In 1886 (Hall) and Heroult (French) proposed the cryolite-alumina molten salt electrolytic aluminum smelting method. In 1888, Pittsburgh established the first electrolytic aluminum plant and aluminum production entered a new phase. In 1956, the world’s aluminum output surpassed copper, making it the first non-ferrous metal.
The nature of aluminum
The standard electrode potential of aluminum is (25°C)-1.662 volts, and the electrochemical equivalent is 0.3356 g/(ampere hour). The main physical properties of metallic aluminum with a purity of 99.99% are as follows: density (20°C) of 2.70 g/cm3; melting point of 660.1°C; boiling point of 2520°C; average specific heat (0 to 100°C) of 917 J/kg·K; The heat of fusion is 10.47 kJ/mol; the heat of vaporization is 291.4 kJ/mol (estimated value); the thermal conductivity (0 to 100°C) is 238 W/(m·K); the resistivity (20°C) is 2.67 μΩ/cm.
Aluminum resources
The average content of aluminum in the earth's crust is 7.47%, ranking third in oxygen and silicon. The industrial reserves of bauxite found worldwide are about 25 billion tons, plus a total of about 35 billion tons of long-term reserves. Countries with large reserves and high output include Guinea, Australia, Brazil, Jamaica, India and other countries. The bauxite mines in these countries mostly belong to the high-iron and low-silicon gibbsite type and are suitable for the production of alumina using the simpler Bayer process. The proven bauxite in China is mainly distributed in places such as Henan, Shanxi, Guizhou, Shandong, and Guangxi. Except in some areas, it is a diaspore type with low iron and high aluminum. China also has a rich alum mine. The provinces of Zhejiang and Anhui have potassium alum resources of 100 million tons and are the raw materials for the production of alumina and potash fertilizers. In addition, abundant nepheline resources are also found in Yunnan and other places.
Preparation of aluminum
The production of aluminum includes the production of alumina from ore and the production of aluminum from alumina. Alumina production methods mainly include Bayer process, soda lime sintering process, and Bayer-sintering process. The Bayer process has been the main method of producing alumina, and its production accounts for about 95% of the total alumina production worldwide.
The use of aluminum
Due to its excellent physical properties, aluminum has been widely used in various sectors of the national economy and defense industries. Aluminum is a light structural material with light weight and high strength. Various transportation tools for sea, land and air, especially airplanes, missiles, rockets, artificial earth satellites, etc., use a large amount of aluminum, and the amount of aluminum for a supersonic aircraft. At 70% of its own weight, aluminum for missiles accounts for more than 10% of its total weight. Vehicles made of aluminum and aluminum alloys can reduce energy consumption. The energy saved is far greater than when aluminum is used. The energy consumed; aluminum alloy doors and windows for building materials are used in the construction industry; solar collectors made of aluminum can save energy; in terms of power transmission, the amount of aluminum is the highest, and 90% of high-voltage electric wires are Made of aluminum; in the food industry, from storage tanks to cans, and beverage containers are mostly made of aluminum; aluminum powder can be used as a reducing agent for refractory metals (such as molybdenum, etc.) and as a deoxidizer in steelmaking. Pots, pans, spoons, etc. used in daily life are mostly made of aluminum. Aluminum compounds such as aluminum hydroxide can be used to prepare aluminum salts, adsorbents, mordants and ion exchangers, as raw materials for enamels, refractories, etc., used as pharmaceuticals for acid drugs, neutralize gastric acid and treat ulcers. Role; sodium meta-aluminate is commonly used in printing and dyeing fabrics; anhydrous aluminum chloride is a commonly used catalyst in the petroleum industry and organic synthesis; hexahydrate aluminum chloride can be used to prepare deodorants, safe disinfectants; sodium hexafluoroaluminate ( That is, cryolite) is commonly used as an insecticide in agriculture; aluminum phosphide emits a highly toxic phosphine gas in the presence of moisture or acid, which can poison pests, and is used as a fumigant for agricultural pests in barns; aluminum sulphate is commonly used. Used as filler for papermaking; aluminum nitrate can be used for tanning and white thermoelectric filaments, but also as a mordant; aluminum silicate is commonly used in the manufacture of glass, ceramics, paint pigments and paint, rubber and plastic fillers; sucralfate Also known as Weifuning, the scientific name sucrose sulphate alkali aluminum salt, it can bind pepsin, directly inhibit the proteolytic activity, the effect is more durable, and can form a protective film, has a strong protective effect on the gastric mucosa and Acid production, help Help mucosa regeneration, promote ulcer healing, low toxicity, is a good therapeutic agent for gastrointestinal ulcers. In recent years, a number of new aluminum-containing compounds have been developed, such as aluminum oxide used as a wear layer for composite wood flooring, as well as aluminum alkyls, nano-alumina, and the like. With the development of science, people will make more and better use of aluminum and compounds for the benefit of mankind.
The word aluminium is derived from the Roman alumen (alum). In 1746 German scientist Porter (JHPott) made alumina from alum. In 1807, the Englishman H. Davy tried to electrolyze fused alumina to obtain metal. In the following year, Davy gave the envisioned metal the name alumium and later changed to aluminum. In 1825, Danish scientist H Coersted reduced anhydrous aluminum chloride with potassium amalgam to obtain several milligrams of metallic aluminum. In 1827, German scientist Waller (F.Wohler) used potassium to reduce alumina to obtain a small amount of metallic aluminum. In 1854, the French scientist, SC Deville, used sodium to reduce NaAlCl4 complex salt to produce aluminum. He also built factories to produce helmets, cutlery and toys. The price is high and it is equivalent to gold. In 1886 (Hall) and Heroult (French) proposed the cryolite-alumina molten salt electrolytic aluminum smelting method. In 1888, Pittsburgh established the first electrolytic aluminum plant and aluminum production entered a new phase. In 1956, the world’s aluminum output surpassed copper, making it the first non-ferrous metal.
The nature of aluminum
The standard electrode potential of aluminum is (25°C)-1.662 volts, and the electrochemical equivalent is 0.3356 g/(ampere hour). The main physical properties of metallic aluminum with a purity of 99.99% are as follows: density (20°C) of 2.70 g/cm3; melting point of 660.1°C; boiling point of 2520°C; average specific heat (0 to 100°C) of 917 J/kg·K; The heat of fusion is 10.47 kJ/mol; the heat of vaporization is 291.4 kJ/mol (estimated value); the thermal conductivity (0 to 100°C) is 238 W/(m·K); the resistivity (20°C) is 2.67 μΩ/cm.
Aluminum resources
The average content of aluminum in the earth's crust is 7.47%, ranking third in oxygen and silicon. The industrial reserves of bauxite found worldwide are about 25 billion tons, plus a total of about 35 billion tons of long-term reserves. Countries with large reserves and high output include Guinea, Australia, Brazil, Jamaica, India and other countries. The bauxite mines in these countries mostly belong to the high-iron and low-silicon gibbsite type and are suitable for the production of alumina using the simpler Bayer process. The proven bauxite in China is mainly distributed in places such as Henan, Shanxi, Guizhou, Shandong, and Guangxi. Except in some areas, it is a diaspore type with low iron and high aluminum. China also has a rich alum mine. The provinces of Zhejiang and Anhui have potassium alum resources of 100 million tons and are the raw materials for the production of alumina and potash fertilizers. In addition, abundant nepheline resources are also found in Yunnan and other places.
Preparation of aluminum
The production of aluminum includes the production of alumina from ore and the production of aluminum from alumina. Alumina production methods mainly include Bayer process, soda lime sintering process, and Bayer-sintering process. The Bayer process has been the main method of producing alumina, and its production accounts for about 95% of the total alumina production worldwide.
The use of aluminum
Due to its excellent physical properties, aluminum has been widely used in various sectors of the national economy and defense industries. Aluminum is a light structural material with light weight and high strength. Various transportation tools for sea, land and air, especially airplanes, missiles, rockets, artificial earth satellites, etc., use a large amount of aluminum, and the amount of aluminum for a supersonic aircraft. At 70% of its own weight, aluminum for missiles accounts for more than 10% of its total weight. Vehicles made of aluminum and aluminum alloys can reduce energy consumption. The energy saved is far greater than when aluminum is used. The energy consumed; aluminum alloy doors and windows for building materials are used in the construction industry; solar collectors made of aluminum can save energy; in terms of power transmission, the amount of aluminum is the highest, and 90% of high-voltage electric wires are Made of aluminum; in the food industry, from storage tanks to cans, and beverage containers are mostly made of aluminum; aluminum powder can be used as a reducing agent for refractory metals (such as molybdenum, etc.) and as a deoxidizer in steelmaking. Pots, pans, spoons, etc. used in daily life are mostly made of aluminum. Aluminum compounds such as aluminum hydroxide can be used to prepare aluminum salts, adsorbents, mordants and ion exchangers, as raw materials for enamels, refractories, etc., used as pharmaceuticals for acid drugs, neutralize gastric acid and treat ulcers. Role; sodium meta-aluminate is commonly used in printing and dyeing fabrics; anhydrous aluminum chloride is a commonly used catalyst in the petroleum industry and organic synthesis; hexahydrate aluminum chloride can be used to prepare deodorants, safe disinfectants; sodium hexafluoroaluminate ( That is, cryolite) is commonly used as an insecticide in agriculture; aluminum phosphide emits a highly toxic phosphine gas in the presence of moisture or acid, which can poison pests, and is used as a fumigant for agricultural pests in barns; aluminum sulphate is commonly used. Used as filler for papermaking; aluminum nitrate can be used for tanning and white thermoelectric filaments, but also as a mordant; aluminum silicate is commonly used in the manufacture of glass, ceramics, paint pigments and paint, rubber and plastic fillers; sucralfate Also known as Weifuning, the scientific name sucrose sulphate alkali aluminum salt, it can bind pepsin, directly inhibit the proteolytic activity, the effect is more durable, and can form a protective film, has a strong protective effect on the gastric mucosa and Acid production, help Help mucosa regeneration, promote ulcer healing, low toxicity, is a good therapeutic agent for gastrointestinal ulcers. In recent years, a number of new aluminum-containing compounds have been developed, such as aluminum oxide used as a wear layer for composite wood flooring, as well as aluminum alkyls, nano-alumina, and the like. With the development of science, people will make more and better use of aluminum and compounds for the benefit of mankind.