Improve Kaolin Whiteness
Another major and most important factor that determines the Beneficiation process to choose is the type of impurities in the Kaolin. The whiteness and opacity of Kaolin clay greatly depends upon its impurity contamination. Again the impurity contamination in the Kaolin Clay depends upon its origination.
Primary Kaolin from deposits may be different or same will generally show a great variation in its mineral content. In general, the Primary Kaolin contains non-kaolin minerals that are resistant to alteration. Some minerals that are generally found with primary kaolin are quartz, muscovite mica, vermiculite, biotite, feldspar, illite, etc. Most of these are present in Kaolin due to less altered rock or partially kaolinized rock.
Secondary or Sedimentary Kaolin does not contain many contaminants in high concentration. Quartz and muscovite content in this kaolin is low, as the coarse and slit sized particles will be separated from the clay during the sediment transport. This Kaolin contains impurities such as illite, hydroxyl vermiculite, iron oxides, iron sulphides, and iron hydroxides.
To be contd….
