Unlike the base metal ores, bauxite does not require complex processing because most of the bauxite mined is of an acceptable grade. Ore quality can be improved by relatively simple and inexpensive processes for removing clay, known as beneficiation, which include washing, wet screening and mechanical or manual sorting.
Enrichment or dressing of an ore is carried out by the following methods. Levigation : The powdered ore is washed in a jet of water. The lighter, rocky and earthy impurities are washed away by water, while heavier ore particles are left behind to settle down at the bottom. This process is also called hydraulic washing.
Shaffer , in his contribution to SME Mineral Processing Handbook chapter on alumina, literally writes that the intrincate milling and mineral dressing techniques common in the base metal industry are not used on bauxite. Sometimes, the ROM ore is crushed and screened.