Bauxite, an aluminium ore, is the world's main source of aluminium. It consists mostly of the minerals gibbsite, boehmite anddiaspore, mixed with the two iron oxides goethite and haematite, the clay mineral kaolinite and small amounts of anatase and ilmenite. Sometimes there are some minerals like calcium, magnesium and sulfur in it.
Types of Bauxite Ores:
1. According to their impurities, bauxite ores can
be classified into high-alkali bauxite, high-titanium bauxite and high-iron bauxite.
2. According
to the mineralogy: bauxite ores have 3 kinds: respectively, trihydrate or gibbsitic bauxite, mixed
bauxite, monohydrate bauxite.
The solutions for processing bauxite ores:
The main methods of bauxite
beneficiation are ore washing, floatation, magnetic separation and chemical beneficiation. Of them, ore
washing is the simplest and most effective way of improving the alumina-silica ratio. Through ore
washing, the ratio can increase by 200%. And it is more recommended for ores with loose texture.
Floatation can be used to separate dispore and kaoline while magnetic separation fits for the ores with
iron. At last, chemical beneficiation mainly refers to desilication by roasting. However, for different
types of bauxite ores, the methods vary from one to another:
Gibbsite-kaoline Bauxite:
When it comes to the beneficiation process of
gibbsite-kaoline bauxite, the sand would be separated from mud first. After coarse grinding, the
magnetic separation is used to remove iron and floatation is then carried out.
High-silica Bauxite:
As for high-silica bauxite, floatation is effective.
High-iron Bauxite:
Different ways of de-ironing are used in terms of the
content, type, distribution of iron in the process of high-iron bauxite beneficiation. Magnetic
separation, roasting magnetic separation and de-iron by carrier-floatation are taken priorities.
Common Equipment:
Vibrating Feeder;
PEW Jaw Crusher; CS Cone Crusher;
VSI Impact Crusher
MTW European Grinding Mill; SCM Ultrafine Mill
Floatation Machine;
Magnetic Separator
