Improve Kaolin Whiteness
Note that China Clay processing for improving whiteness greatly depends upon the type of iron contamination. As mentioned in previous blog type of iron impurity Free or Structural plays a major role in determining process for improving whiteness. The Kaolin wet beneficiation process for improving whiteness consists mainly of degritting, fractionation by special centrifuging, magnetizing by high gradient magnetic separator, selective flocculation by adding additives, chemical bleaching, filtering and then drying. The above said series of process will assist in removing impurities like iron oxides, titanium oxides, mica and quartz. Chlorination step can be included to remove iron and titanium impurities.
1. The Kaolin has to be degritted and fractioned in Centrifuge.
2. Then the centrifuged Kaolin has to be sieved through sieves ranging from 6 mesh to 400 mesh
3. Kaolin of 400 mesh sizes are then magnetized through a HGMS of about 14,000 Gauss range.
4. The non magnetic part is then chemically treated with Sodium Dithionite or any other chemical reagent depending upon impurity to handle.
