Bauxite is only a part of bauxite, and the requirements for bauxite in various places are inconsistent. For example, Henan requires alumina content above 55, aluminum-silicon ratio above 4, iron content below 22, and sulfur content below 2. There are great differences in each region, and the main uses are alumina plants and refractory materials.
Bauxite (aluminous soil; bauxite), also known as bauxite or bauxite, is mainly composed of alumina, which is hydrated alumina containing impurities, and is an earthy mineral. White or off-white, brownish-yellow or light red due to iron content. Density 3.45g/cm3, hardness 1-3, opaque and brittle. Extremely difficult to melt. Insoluble in water, soluble in sulfuric acid and sodium hydroxide solution. It is mainly used for aluminum smelting and refractory materials.
Main ingredient
The scientific name of bauxite ore is bauxite ore, bauxite. Its composition is extremely complex, and it is a general term for a variety of hydrous alumina ores from very different geological sources. Such as boehmite, diaspore and gibbsite (Al2O3 · 3H2O); some are composed of boehmite and kaolinite (2SiO2 · Al2O3 · 2H2O).
Some are mainly kaolinite, and with the increase of kaolinite content, it is formed into general bauxite or kaolinite clay. Bauxite is generally formed by chemical weathering or exogenous action. There are few pure minerals and always contain some impurity minerals, more or less clay minerals, iron minerals, titanium minerals and detrital heavy minerals.
The definition of bauxite is not uniform enough, which is related to the resource situation and industrial demand of each country. The names of each period are also inconsistent, but basically the same. In China, it is generally believed that: "Bauxite refers to the ore with a high aluminum content (above 40%), and those whose aluminum-silicon ratio is greater than 2.5 (A/S≥2.5), and those less than this value are called clay or aluminum. soil shale or aluminous rock".
