Apr . 22, 2025 17:39
Kaolin, also known as china clay, primarily originates from the weathering and hydrothermal alteration of feldspar - rich rocks. Feldspar, a common mineral in igneous rocks like granite, gradually breaks down under the influence of water, heat, and chemical agents over long geological periods. This process, known as kaolinization, transforms feldspar into kaolinite, the main mineral component of kaolin.
Large scale kaolin deposits are often found in regions that have experienced significant geological activity. For example, in the United States, major deposits exist in Georgia, where sedimentary kaolin formed through the weathering of ancient granite masses and subsequent transportation and deposition of kaolinite particles by water.
Kaolin can also be sourced from residual deposits, where the original rock weathers in place, and from secondary deposits formed by the redeposition of weathered materials.
Kaolin powder has many uses. In the paper industry, it is used as a coating to improve the whiteness and smoothness of paper, and as a filler to increase its opacity and stiffness. In the ceramics industry, it is an important raw material for making the body and glaze, which can improve the plasticity and quality of ceramics. In the rubber industry, it serves as a filler to enhance the hardness and wear - resistance of rubber, and can also improve the processing performance. In the plastics industry, kaolin powder is added to increase the rigidity and heat resistance of plastics. It is also used in cosmetics to absorb oil and dirt on the skin, and in the pharmaceutical industry as an excipient. Moreover, it can be used as a catalyst support in some chemical reactions.
