Aluminium — the most famous metal in modern industry, but until the twentieth century is considered a rare enough, silvery-white in color, with a «happy» atomic number 13, unbiased by generalization synthetic element lurking in the bowels of the earth and standing in the third group of the third periodic table period after oxygen and silicon, readily melting at a melting temperature of 660 ° C, but boiling at 2500oS and receiving different shape under mechanical stress, with high thermal and electrical conductivity is not amenable to corrosion due reliable enzyme film was first prepared by potassium smelting chloride aluminum with a further distillation of mercury Hanson Oersted in 1825.
American Charles Hall and Frenchman Paul Heroult in 1886 put experiments on the dissolution of alumina, and simply aluminum oxide of Al2O3, in the magma cryolite Na3AlF6 c further physico-chemical process, consisting in the isolation of the electrodes combined parts compacting substances due to rehydration on the conductors, by passing electric current through them. But, since this process was very time consuming and further its spread, he received only in the twentieth century.
With high light reflectivity data, low permeability, a rare negative oxidation state, fits well in kupelyatsii with many metals to increase their heat resistance and its half-century has seven hundred and twenty thousand years. The percentage of the earth's crust is 7,45−8,14% of the total mass of the Earth.
Due to the excellent ductility and plasticity is used for the manufacture of electrical wires and chemical equipment. At half the weight of copper. Due to the treated surface deep oxidants can be used for transportation and storage of nitric acid. His «grace» allows you to turn when rolling into thin sheets and even the foil, which is indispensable for packaging products, and various drugs, and good mechanical properties and compatibility with other metals, weighing rocket, aircraft, shipbuilding, auto-modeling. Crushed into tiny particles in the air is easy to ignite. It comes in contact with chlorine and bromine even at ordinary temperature. In a high temperature environment is combined with carbon and nitrogen. But should it lose with a protective layer with solutions of ammonium salts, as he immediately «defile» metal as a reducing agent. No problem comes into contact with simple materials, for example, with oxygen, forms alumina 4Al + 3O2 = 2Al2O3, halogen except fluorine, creates a chloride, bromide or iodide, aluminum 2Al + 3Hal2 = 2AlHal3 (Hal = Cl, Br, I) with fluorine when heated forms aluminum fluoride 2Al + 3F2 = 2AlF3, with sulfur — sulfide aluminum 2Al + 3S = Al2S3, nitrogen — aluminum nitride 2Al + N2 = 2AlN, carbon — aluminum carbide 4Al + 3C = Al4S3 etc. .
By water he sustained response, but is again save him from the security deposit, the following occurs: 2Al + 6H2O = 2Al (OH) 3 + 3H2
Saturated HNO3 and H2SO4 at low air temperature of aluminum is almost no effect, but the medium enriched with acid gradually dissolve it. Pure aluminum is stable to hydrochloric acid, but the usual technical metal dissolved therein.
Aluminium salts in solution disappears by hydrolysis with an acid or alkaline medium, for example, Na2CO3.
In a series of stress it is between the Mg and Zn, in stable compounds — is trivalent.
In combination with oxygen, emits large amounts of heat 1676 kJ / mol. Therefore, when the metal oxide raskalivanii mixed with aluminum powder vigorous reaction occurs, leading to release of free metal oxide taken. Termites are sometimes used for welding the individual steel parts, in particular for the docking of tram rails, steel pipes and steel structures. The equation of the following: 8Al + 3Fe3O4 = 4Al2O3 + 9Fe + 3350 kJ. Moreover, t heat about 3000oS.
In 1859, Russian chemist Beketov, was opened aluminothermy — reception of extraction of metals by high temperature 2400 ° C, for chromium, vanadium, manganese, tungsten and other metals and alloys in the free state. According to his method in the German town was built Glemingeme factory producing aluminum and five years of its existence released to the industry for over fifty-eight tons of silver metal.
Aluminium oxide — a white, refractory and insoluble in water weight. Natural mineral corundum of Al2O3, or produced synthetically, distinguished by high hardness and is fit for the production of abrasive wheels, bars and so on. D. The crushed form of Al2O3, and simply sandpaper, clean metal surfaces and is indispensable in the manufacture of sandpaper. For the same purposes often take Al2O3, obtained by fusing bauxite (the technical name — Alundum).
Mineral, ruby red, a variety of corundum (chromium impurity) and blue sapphire (admixture of titanium and iron) gems. It is produced in the laboratory and used for technical purposes, such as for the manufacture of parts of precision instruments, watches and stones, etc. Crystals of Sardis, containing a small admixture of Cr2O3, used as a photon generator -. Lasers give birth induced beam of monochromatic radiation.
Aluminum interacts with strong alkalis, forming aluminates:
NaOH + Al (OH) 3 = Na [Al (OH) 4]
They are readily soluble in water, if a monovalent, and they can be manufactured by melting relevant Al2O3 with metal oxides. Formed metaalyuminaty from metaalyuminievoy acid Halo2, most of them are insoluble in water.
With acids Al (OH) 3 forms a salt. Secondary, most of the strong acid is perfectly soluble in water and hydrolyzed significantly, so they give acidic solutions. Even stronger hydrolysis of soluble aluminum salts and weak acids.
By solvation with the main AlH3 hydride in ether solution formed hydroaluminates LiH + AlH3 = Li [AlH4] — white solids used mainly in organic synthesis.
Aluminum sulphate Al2 (SO4) 3.18H2O occurs when exposed to hot sulfuric acid to aluminum oxide or kaolin. Good for water purification and preparation of certain grades of paper.
Potassium alum KAl (SO4) 2.12H2O are indispensable for tanning, dyeing industry as a mordant of cotton fabrics.
Of the remaining derivatives of aluminum acetate can not forget the acetate salts of Al (CH3COO) 3, as required in the textile industry in dyeing fabrics, and in medicine for lotions and compresses. aluminum Mineral water soluble and aluminum phosphate is insoluble in either water or in acetic acid, but is absorbed by strong acids and alkalis.
Plants, kidney, small living organisms contain aluminum. In humans, it is only 10,000 shares a percentage of the total body weight. The biological role of its not clear, toxic compounds do not possess it.