The scientific name of bauxite, alumina bauxite. Its composition is very complex, is a general term for a variety of geological sources of very different aqueous alumina ore. Such as boehmite, diaspore and gibbsite (Al2O3 · 3H2O); some are diaspore and kaolinite (2SiO2 · Al2O3 · 2H2O) together; some is dominated by kaolinite, and with the increase of content of kaolinite, constitute the general bauxite and kaolinite clay. Bauxite is generally formed chemical weathering or exogenous effect, few pure mineral, always contains some impurities, more or less rich in clay minerals, iron minerals, titanium mineral and detrital heavy minerals etc..
Bauxite definition name is not uniform, and the resources of the state and the industrial demand. The name of each period is also different, but basically the same. In our country generally think: "refers to the amount of bauxite ore containing high (above *0%), aluminum silicon ratio greater than 2.5 (A/S ≥ 2.5), which is less than this value are called clay or shale and bauxite aluminous rocks". In China's proven reserves of bauxite, diaspore type bauxite accounted for about *8% of total reserves.
Application
(1) in aluminium industry. For defense, aerospace, automotive, electronics, chemical industry, daily necessities and so.
(2) precision casting. Bauxite is processed into fine powder and made into mold. Used in military, aerospace, communications, instrumentation, machinery and medical equipment department.
(3) for refractory products. High alumina bauxite refractory degree is up to ***0 ℃, high chemical stability, good physical properties.
(4) aluminum silicate refractory fiber. Has the advantages of light weight, high temperature resistance, good thermal stability, low thermal conductivity, heat capacity and has the advantages of small resistance to mechanical shock. For the iron and steel, nonferrous metallurgy, electronics, petroleum, chemical, aerospace, atomic energy, defense and other industries. It is the high Al clinker into the melting temperature of about ***0 ~ ***0 ℃ high temperature electric arc furnace, the high melting temperature, high pressure and high speed air or steam injection, cooling, a white "cotton" *- aluminum silicate refractory fiber. It can be pressed into refractory fiber blanket, board or woven into cloth instead of smelting, chemical, glass and other industrial furnace lining. Firefighters used refractory fiber cloth made clothes.
(5) with magnesia and bauxite as raw material, adding appropriate binder, used for pouring ladle lining the whole barrel effect.
(6) made of alumina cement, abrasive materials, ceramic industry and chemical industry in a variety of aluminum compounds.
The number of technical conditions of bauxite refractories:
Classification of chemical composition / refractoriness volume density
Al2O3 CaO Fe2O3
Super >*5 <0.6 <2.0 >***0 >3.0
A >*0 <0.6 <3.0 >***0 >2.8
The two level of *0~*0 <0.8 <3.0 >***0 >2.*5
Two class B *0~*0 <0.8 <3.0 >***0 >2.*5
Three *0~*0 <0.8 <2.5 >***0 >2.*5