Details of the production of alumina raw materials: bauxite
So far, the production of alumina in two main raw materials: one is to use natural or sintered bauxite fused directly into corundum, alumina corundum, corundum-white; the other is to use commercial alumina fused or sintered as corundum, dense corundum, tabular alumina, sintered corundum and so on. While industrial use more than 95% of alumina bauxite extraction. Bauxite is an important raw material visible corundum. With alunite and nepheline can be extracted alumina.
Also known as bauxite bauxite or bauxite, the main mineral is a boehmite (Al2O3 · H2O) and gibbsite (Al2O3 · 3H2O). Depending on the structure of a boehmite, can be divided into a diaspore (α-Al2O3 · H2O or diaspore) and a boehmite (γ-Al2O3 · H2O or boehmite, Baume stone) . Bauxite mineral name is not called, but a diaspore, a boehmite and gibbsite mixture, the main chemical ingredient Al2O3, typically at 40% to 80%. Natural chemical composition of bauxite magazine big changes, in addition to Al2O3, there are SiO2, TiO2, Fe2O3, CaO, MgO, K2O, Na2O, these chemical composition of the following minerals: gibbsite, a boehmite, and sillimanite-based mineral (ie, sillimanite, andalusite, kyanite, the chemical formula (Al2O3 · SiO2), kaolinite (Al2O3 · SiO2 · H2O), rutile (TiO2) and dickite and iron minerals. bauxite mainly oolitic, lenticular, debris and cryptocrystalline (mashed) structure, as well as earthy, dense block structure and from white to ocher of everything between colors, generally red high iron, low iron content was gray, because of the different cementation material, a large color change, the advantages of red-