What method is used to remove iron from kaolin

Impurities such as quartz, feldspar, mica, aluminum oxide, iron mineral, titanium oxide, and organic matter exist in the kaolin raw ore to varying degrees. It must be beneficiated and purified in demanding applications.

The process of beneficiation and purification of kaolin ore depends on the nature of the ore and the end use of the product. There are two processes used in industrial production: dry iron removal and wet iron removal. Usually hard kaolin is produced by dry method and soft kaolin is produced by wet iron removal.

The dry iron removal process is a simple and economic process. The original ore is crushed by hammer and cage crushers, and the hot air in the cage crusher is used to reduce the water content of kaolin from 20% to 10%. It is then finely ground by a blown Raymond mill equipped with a centrifugal separator and cyclone dust collector. This process can remove most of the sand and gravel. The products are usually used for low-cost fillers in the rubber, plastics and paper industries.

The wet iron removal process includes three stages: ore preparation, mineral processing and product processing.

The preparation stage includes batching, crushing and tamping operations.

Tamping is to mix raw kaolin ore with water and dispersing agent in the tamping machine to make pulp. The tamping operation can disperse the raw ore, prepare kaolin ore pulp of appropriate fineness for the sorting operation, and remove large-grain sandstone at the same time.

The beneficiation stage may include operations such as hydrocyclone, flotation, selective flocculation, magnetic separation, chemical treatment (bleaching), etc.

The final product without magnetic separation has a low whiteness, and only the magnetic separator can be configured in the process to achieve the highest whiteness clay product by foam flotation or selective flocculation.