What are the bauxite beneficiation processes?

The main alumina-containing minerals present in bauxite are: gibbsite, boehmite and diaspore

Other gangue or impurity minerals commonly found in bauxite include: clays, usually kaolinite, quartz, iron oxides and iron oxyhydroxides (hematite and goethite), titanium dioxide in the form of anatase or rutile.

Mineralogy is very important because it determines the refining conditions that must be used and has a strong impact on the economics of processing a particular bauxite ore.

For different types of bauxite, there will be certain differences in the sorting process.

 (1) For gibbsite type bauxite, the mud and sand are usually separated first, then magnetic separation is used to remove iron after coarse grinding, and flotation is used after mud grinding.

 (2) Boehmite oolitic bauxite beneficiation process. Usually fine-grained hematite, oolitic chlorite and boehmite are associated. After the mineral processing is screened and washed, the coarse grade is selectively crushed and then classified. The coarse grade is a product with low aluminum-silicon ratio. Selective flocculation of fine particles removes impurity iron.

 (3) High silicon bauxite. Generally, flotation method is used. Aluminum ore flotation agents include fatty acids and sulfonates, sodium hexametaphosphate, tannins, sodium pyrophosphate, etc.

       (4) High-speed rail bauxite. According to the type and characteristics of iron minerals, iron removal methods include magnetic separation, roasting magnetic separation, carrier flotation, etc.

       The bauxite beneficiation process is complex, difficult to operate, and has many influencing factors. Therefore, various factors should be comprehensively analyzed and considered in actual production. In fact, flotation is the most commonly used method in bauxite beneficiation, but it is another matter that some associated organisms in bauxite are not suitable for flotation.

Currently, a large amount of mineral processing tailings and red mud produced in alumina production are directly piled as waste in the bauxite mining industry, resulting in a serious waste of resources. At the same time, we will strengthen the resource utilization of bauxite tailings treatment. Therefore, when selecting a bauxite beneficiation process, it should be determined based on the characteristics of the ore.