Improving the whiteness of kaolin is equivalent to purifying kaolin, which can remove impurities such as quartz stone and titanium minerals in kaolin. More purified kaolin can mean higher quality of related kaolin products, and by making full use of kaolin resources, businesses get better economic benefits.
Kaolin: Origin of the white additive. The name kaolin derives from the Chinese and means high ridge. High ridge is a reference to the hill in south eastern China where the clay was originally discovered and used. In the 7th and 8th centuries, the Chinese were the first to use kaolin as a mineral additive to make porcelain.
Chemical bleaching: Impurities in kaolin can be oxidized into solubles by bleaching, and then washed and removed to improve the whiteness of kaolin products. However, the cost of chemical bleaching is relatively high, and it is usually used for kaolin concentrate that needs further purification after impurity removal.
This process can widen the firing temperature range, prevent the ceramic body from deforming easily, and improve the whiteness of ceramics.At the same time, kaolin itself also has the characteristics of bonding, plasticity, bonding, suspension and so on, which can improve the formability of porcelain clay and enamel, and is more conducive to ...
The significant properties of kaolin of greatest value to the paper industry are whiteness, low viscosity, non abrasiveness, controlled particle sizes, and flat hexagonal plates. Opacity is an extremely important property to the paper industry and Fig. 7 shows the relationship between the particle size of the kaolin and opacity.
What is the way to improve whiteness? The kaolin itself is white, and the iron impurities show rose red, brownish yellow, iron and titanium impurities will affect the whiteness of calcination. The method of increasing the whiteness is obviously complicated.
Industrial grade Kaolin deposits in Sri Lanka are located in Boralesgamuwa and Meetiyagoda. Two distinct grades of Kaolin are produced at Meetiyagoda refinery, based on the whiteness index . The presence of iron oxides significantly affects the