Bauxite mining name bauxite, bauxite. Its composition is extremely complex and it is a generic term for hydrated alumina ore with a variety of geological sources that are very different. Such as boehmite, diaspore and gibbsite (Al2O3·3H2O); some are composed of diaspore and kaolinite (2SiO2·Al2O3·2H2O); some are mainly kaolinite, and The increase in kaolinite content constitutes ordinary bauxite or kaolinite clay. Bauxite is generally formed by chemical weathering or exogenous action. There are few pure minerals, always containing some impurity minerals, and more or less clay minerals, iron minerals, titanium minerals, and detrital heavy minerals.
The definition of bauxite is not uniform enough. This is related to the resources and industrial needs of various countries. The names are not the same in each period, but they are basically the same. In China, it is generally considered that “aluminum ore system means that the ore has a high aluminum content (more than 40%), and the ratio of aluminum to silicon is greater than 2.5 (A/S ≥ 2.5). If it is less than this value, it is called clay mineral or aluminum. Soil shale or aluminous rock." Of the proven reserves of bauxite in China, boehmite-type bauxite accounts for about 98% of the country's total reserves.
At present, 49 countries are known to have bauxite deposits. China has abundant bauxite resources, about 3.7 billion tons, which ranks among the top countries in the world. Guinea, Australia, and Brazil are both the world’s largest countries in terms of bauxite resources. However, the only countries that produce high-alumina bauxite for refractories are Guyana and China. Bauxite in other countries has high iron content and is used in aluminum and abrasive materials.
China's bauxite resources are relatively abundant, and 205 bauxite ore deposits have been identified in 18 provinces, autonomous regions, and municipalities directly under the Central Government, of which 72 are large-scale production sites (excluding Taiwan). Mainly in Shanxi, Shandong, Hebei, Henan, Guizhou, Sichuan, Guangxi, Liaoning, Hunan and other places.
use
(1) Aluminum smelting industry. For defense, aviation, automotive, electrical appliances, chemicals, daily necessities, etc.
(2) precision casting. Bauxite clinker is processed into fine powder and cast into molds. For the military, aerospace, communications, instrumentation, machinery and medical devices sector.
(3) For refractory products. High alumina bauxite clinker refractoriness up to 1780°C, strong chemical stability, good physical properties.
(4) Aluminosilicate refractory fiber. It has the advantages of light weight, high temperature resistance, good thermal stability, low thermal conductivity, small heat capacity and mechanical vibration resistance. For steel, non-ferrous metallurgy, electronics, petroleum, chemical, aerospace, atomic energy, national defense and other industries. It puts the high-alumina clinker into a high-temperature arc furnace with a melting temperature of about 2,000-2200°C. After high-temperature melting, high-pressure high-speed air or steam injection and cooling, it becomes a pure white “cottonâ€â€”aluminum silicate. Fire-resistant fiber. It can be pressed into a fiber blanket, board or woven cloth instead of smelting, chemical, glass and other industrial high-temperature furnace lining firebrick. Firefighters can use fire-resistant fiber cloth to make clothes.
(5) Using magnesia and bauxite clinker as raw materials and adding suitable binders, the overall barrel lining for casting steel drums is very effective.
(6) Aluminium cement, abrasives, ceramic industry, and chemical industry can produce various compounds of aluminum.