Aluminum is a kind of light metal, and its compounds are widely distributed in nature, and the content of aluminum in the earth's crust is only inferior to oxygen and silicon. Metal varieties, aluminum second only to iron and steel, for the second major categories of metal. Aluminum has a special chemical and physical properties, one of today's most commonly used industrial metal, not only has the advantages of light weight, high hardness, but also has good ductility, electrical conductivity, thermal conductivity, heat resistance and resistance to nuclear radiation, the development of the national economy an important basis for raw materials.
Aluminum density and structure

The density of aluminum is about 2.7 of the general metal 1/3 and commonly used aluminum wire conductivity is about 61% copper, thermal conductivity of silver half. Although pure aluminum is very soft and rich in ductility, it can be hardened by cold working and alloy. Bauxite is an important source of aluminum, to make a pound of alumina requires about two pounds of bauxite, while the production of a pound of aluminum requires two pounds of alumina.

Aluminum oxide, hydroxide and oxygen containing aluminum silicate in the natural world are found to have very little natural metal. There are 258 kinds of minerals containing known rare minerals, including about 43. In fact, there is no general distribution of the aluminum deposits of pure minerals, and there are impurities. From the view of economy and technology, not all aluminum mineral can become industrial raw materials. For the extraction of the metal aluminum is mainly composed of diaspore bauxite, boehmite or gibbsite.
One water duralumin stone, also known as the aluminum water stone, structural and molecular formula respectively AlOOH and Al2O3? H2O orthorhombic and crystallization intact is columnar, tabular, scaly, acicular and prismatic. The water and aluminum in ore generally contain TiO2SiO2Fe2O3Ga2O3Nb2O5Ta2O5P2O3 and so on. Diaspore is dissolved in acid and alkali, but in under normal temperature and pressure solution is very weak, under high temperature and high pressure and strong acids or alkalis concentration to degrade completely. One water duralumin stone is formed in acidic medium, and a water boehmite, hematite, goethite, kaolinite, chlorite and pyrite in symbiosis. The hydration can be turned into gibbsite, and dehydration can become alpha alumina can be account of kaolinite, pyrite, siderite, chlorite.
A soft water aluminum stone also known as boehmite, boehmite, structure type to AlOOH molecular formula is Al2O3? H2O orthorhombic and crystallization intact is rhombohedral, prismatic shape, prismatic, needle, fibrous and hexagonal plates like. A water soft aluminum ore in the ore often contains Fe2O3TiO2Cr2OGa2O3 and other similar kinds of image. Water soluble in acid and alkali. The mineral formed in acidic medium, mainly in the accumulation of bauxite, and its characteristics are associated with the. Can be a diaspore stone, gibbsite and kaolinite metasomatic and dehydration can be changed into diaspore and Gangyu, water can be turned into gibbsite.
Sanshui aluminum stone, also known as gibbsite stone, aluminum hydroxide stone, structure type aloh molecules for Al2O3? 3H2O monoclinic and crystallization intact is hexagonal plate, a prism shaped, often have a fine grain like ensemble or twin, ore gibbsite showed irregular aggregates, both of which contain different amounts of TiO2SiO2Fe2O3Nb2O5Ta2O5Ga2O3 matter like or mechanical mixing materials. The aluminum is dissolved in acid and alkali, and its powder is heated to 100 degrees C and can be completely dissolved by 2H. The formation of water in the acidic medium, the weathering crust deposit is a primary mineral, which is associated with kaolinite, hematite, hematite, illite and so on. Three diaspore dehydration can become a boehmite, diaspore and Gangyu can be kaolinite, halloysite and explained.

Chemical composition of aluminum
The chemical composition of bauxite Al2O3SiO2Fe2O3TiO2H2O+ five total components accounted for 95% of the above, the general >98% main components have SCaOMgOK2ONa2OCO2MnO2 organic matter, carbon, and trace components have GaGeNbTaPCoZrVPCrNi. Al2O3 mainly occurs in aluminum minerals - water aluminum, aluminum, aluminum, aluminum, water, and then occurs in the silicon minerals (mainly kaolinite minerals).
Under the condition of endogenous, because silica widespread Al2O3 and SiO2 often are tightly combined into various types of aluminum silicate minerals. These minerals generally aluminum silicon ratio is less than 1 and industry of aluminum ore general requirements of Al2O3 is greater than or equal to 40%Al/Si>1.82.6 therefore conditions rarely formed industrial aluminum deposits.

Laterite forming the residual material discharge and is currently known at home and abroad industrial bauxite surface under the condition of the formation of surface conditions of bauxite formation mainly has two forms: weathering eluvial (more than) mineralization (laterite ore) and weathered - moving freight to deposit or weathering - Transformation - sedimentary ore deposit weathered eluvial (more than) mineralization is aluminized parent rock in the hot and humid climate conditions, the excretory good favorable terrain (such as residual hill and low mountain and plateau) due to water, CO2 and biological weathering decomposition, the parent rock in soluble substances KNaCaMg SiO2 leaching, AlFeTi in situ of bauxite Under the action of weathering - carrying - deposit is aluminiferous rock and laterite weathering crust or the formation of lateritic deposits, gravity, water and acid (sulfuric acid, carbonic acid, organic acids) etc., by mechanical and chemical weathering, erosion, transportation and other physical and chemical modification, hollow hill, valley, offshore basin of lake or coastal lake, limitations in the basin on the formation of bauxite and water medium environment formation sedimentary bauxite.