Bauxite (aluminoussoil; bauxite), also known as bauxite or bauxite, is a soil-like mineral. Generally white or off-white, but also brownish-yellow or light red due to iron content. Density range is 3.9~4g/cm3, Mohs hardness is 1~3, brittle, opaque, insoluble in water, soluble in sulfuric acid, sodium hydroxide solution, extremely difficult to melt. In terms of composition, bauxite is a general term for a variety of minerals composed of hydrous alumina ore, and its main component is Al2O3. Some are composed of boehmite (γ-AlO(OH)), diaspore (α-AlO(OH)) and gibbsite (Al2O3 3H2O); some are diaspore and kaolinite (2SiO2·Al2O3·2H2O) are formed together; some are mainly kaolinite, and with the increase of kaolinite content, they are composed of general bauxite or kaolinite clay. Bauxite is generally formed by exogenous action or chemical weathering. There are few pure minerals. It always contains some impurity minerals, and more or less will contain some other clay minerals, titanium minerals, iron minerals and heavy debris. minerals, etc. In industry, bauxite is mainly used as raw material for aluminum smelting and production of refractory materials.
Although the total reserves of bauxite resources in my country are relatively abundant, the structure of most of the ore is not conducive to its application in production, and the proportion of high-quality bauxite with high alumina content is relatively low. The development and utilization of mines have caused adverse effects. Table 1 is a statistical table of the distribution of the silicon-aluminum ratio of bauxite in the country.
It can be seen from Table 1 that the distribution of silicon-aluminum ratio of bauxite in my country is mostly between 4 and 9, accounting for 73.96% of the total reserves. >9 only accounted for 18.62% of the total content.
The mineral composition of the bauxite ore stored in my country is mainly diaspore, which accounts for 99% of the total reserves, followed by a small amount of bauxite mainly composed of gibbsite, which only accounts for the total national 1% of reserves.
The low silicon-to-aluminum ratio and the mineral structure dominated by diaspore limit the application range of bauxite resources in my country. Since the beginning of the 21st century, my country has gradually become the world's largest producer of aluminum products. The relatively limited bauxite resources are mainly used for the production of alumina and metal aluminum, and the high-quality bauxite resources can be used in the direction of refractory materials is limited. In recent years, due to the lack of unified overall management, the development of bauxite resources in my country has been in backward management, only mining but not stripping, random mining, only mining rich ore, abandoning poor ore and other phenomena, the utilization rate of ore is less than 40% , a large number of low-grade bauxite ore and crushed ore can not be effectively used, resulting in almost depletion of my country's special bauxite ore, high-quality and high-grade bauxite resources are increasingly exhausted. As an important raw material for high-alumina refractories, the lack of high-quality bauxite minerals seriously restricts the sustainable and healthy development of my country's refractory industry, causing widespread concern from relevant personnel. To solve related problems, first of all, in the process of mining and processing raw ore, it is necessary to strengthen unified management, adopt a more scientific management plan for beneficiation, and allocate resources rationally. And to vigorously develop the utilization of low-grade bauxite resources.
