Bauxite use and technical and economic indicators

Versatile bauxite ore, the most important uses are: Aluminum metal aluminum refining industry, for grinding materials and refractory materials, high alumina cement and as a raw material. The use of ore is different and its quality requirements vary. The following table is the industry standard (YS/T78-94) for bauxite ore released by the China Nonferrous Metals Industry Corporation in 1994. According to the standard, bauxite is divided into three types: sedimentary diaspore, stacked diaspore and laterite gibbsite, and is divided into LK12-70, LK8-65 and LK5- according to chemical composition. 60, LK3-53, LK15-60, LK11-55, LK8-50, LK7-50, LK3-40 and other nine brands. In addition to the chemical composition of bauxite, the standard requires that the sedimentary diaspore water should not exceed 7%, and the sedimentary diaspore and laterite gibbsite should not exceed 8%. . In addition, the grain size of bauxite ore is required to be no more than 150mm. Bauxite ore must not be mixed with dirt, limestone and other debris.

The industrial extraction of aluminum metal is to first extract alumina from bauxite, and then alumina is electrolyzed to become metal aluminum. According to China's production practice experience, different alumina production methods have different requirements on ore quality. The general requirements are: [next]
1) Sintering method: suitable for treating low-grade ore containing high silicon, requiring Al ₂ O ₃ /SiO _{2 to} be 3 to 5 (or about 3.5) and Fe ₂ O ₃ <10%.
2) Bayer method: suitable for processing rich ore containing high Al ₂ O ₃ and low SiO ₂ , generally requiring Al ₂ O ₃ >65% and Al ₂ O ₃ /SiO ₂ >7. Since no iron oxide with a base in the reaction Bayer Process, only high iron red mud washing large, complex red mud, easily lead to mechanical losses and alumina base, but not aluminum goethite.
3) Combined method: suitable for processing medium-grade bauxite. In China, the mixed method is mainly used to add some low-grade ore in the red mud of Bayer method to improve the ratio of aluminum to silicon in the sintering method. Generally, Al ₂ O ₃ > 60%, Al ₂ O ₃ /SiO ₂ is 5-7, and Fe ₂ O ₃ <10%. For alumina production, sulfur is a very harmful impurity, and high sulfur ore is not suitable.
The following table is an example of several deposits required by the bauxite industry.

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Bauxite used as abrasive material is required to contain Al ₂ O ₃ high, iron and titanium low, generally requiring Al ₂ O ₃ ≥70%, Fe ₂ O ₃ ≤5%, TiO ₂ ≤4.5%, CaO+MgO≤ 1.0%, Al ₂ O ₃ /SiO ₂ ≥12.
The bauxite requirements for fused corundum in China are shown in the table below.

The bauxite ore used as the high alumina cement raw material must have: Fe ₂ O ₃ <2.5%, TiO ₂ <3.5%, R ₂ O (monovalent metal oxide) <1.0%, and MgO <1.0%. The table below shows the specific quality requirements for several cement plants.