Bauxite refers to the ore that can be used in industry, and is collectively referred to as the ore composed of gibbsite and monohydrate as the main minerals. Bauxite is the best raw material for the production of metallic aluminum, and its consumption accounts for more than 90% of the world's total bauxite output. The application fields of bauxite are metal and non-metal. Although the amount of non-metal is small, it has a wide range of uses. Bauxite is used in chemical industry, metallurgy, ceramics, refractory materials, abrasives, adsorbents, light industry, building materials, military industry, etc.
Ore properties and mineral structure
Bauxite is a mixture of multiple minerals (hydroxides, clay minerals, oxides, etc.) with aluminum hydroxide as the main component. It is also called "bauxite" and usually includes gibbsite. , Diaspore, boehmite, hematite, kaolin, opal, quartz, feldspar, pyrite and many other minerals, the chemical composition of which is mainly AI2O3, SiO2, Fe2O3, TiO2, secondary The ingredients include CaO, MgO, K2O, Na2O, S, MnO2 and organic matter, etc., in white, gray, gray-yellow, yellow-green, red, brown, etc.
Beneficiation and purification
Some raw ore mined from bauxite can meet the requirements of the application. Conventional bauxite determines the beneficiation process based on the nature of the associated impurity minerals. At the same time, the impurities associated with aluminum-containing minerals in some bauxites are difficult to remove mechanically or physically.
01
Beneficiation classification
The granular quartz sand and powdered bauxite can be separated by washing, sieving or grading methods to improve the quality. It is suitable for boehmite with high silicon content.
02
Gravity beneficiation
The use of heavy medium beneficiation can separate the iron-containing red clay in the bauxite, and the spiral concentrator can remove siderite and other heavy minerals.
03
Magnetic separation
The use of weak magnetic separation can remove the magnetic iron in the bauxite, and the use of strong magnetic separation equipment such as plate magnetic separator, vertical ring high gradient magnetic separator, electromagnetic slurry magnetic separator can remove iron oxide, titanium and iron silicate, etc. The selection of weak magnetic materials can increase the aluminum content while reducing the cost of alumina production and processing.
04
Flotation
For sulfides such as pyrite contained in bauxite, xanthate flotation can be used to remove; positive and reverse flotation can also be used to remove impurities such as pyrite, titanium, silicon, or select AI2O3 content up to 73% Of high-purity bauxite.
