Purification of Kaolin

Kaolin is a mineral soil that is often used to make porcelain, also known as "porcelain clay". The content of kaolin in China ranks third in the world, mainly composed of montmorillonite, kaolinite and other minerals. Kaolin is widely distributed in China.

At present, kaolin is mainly used for papermaking and rubber and the most important parameter for its application is its whiteness. In papermaking, rubber and other production processes, the degree of whiteness is greater than 78%. Organic matter, iron and manganese and other mineral elements will cause damage in various level to kaolin, and will reduce the whiteness of kaolin to different degrees. Therefore, companies are trying to purify kaolin to increase its added value.

1.Refining of Kaolin

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. At present, the main purification processes are flotation and chemical bleaching to remove organic impurities. Chemical bleaching is used to purify high precision kaolin concentrate to obtain high quality kaolin. Data shows that It is very difficult to obtain high quality kaolin products by single purification process so people usually the combination of several methods to obtain the most purified kaolin.

1.1. Gravity Purification Process

The gravity purification process can be used to remove organic matter, manganese, iron, titanium and other elemental impurities, to reduce the negative impact of impurities on its whiteness, thus achieving the purpose of purification of kaolin. The removal of gangue particles can be done by centrifugal process and the final goal can be achieved according to the density difference of gangue particles. It is suggested that the method of gravity separation of kaolin is effective, and centrifuge washing and screening can remove impurities through washing and grading method. But to reach the high standard of purified kaolin products, relying on gravity separation process alone is far from enough. Usually, other processes, such as leaching and calcination, are also needed to realize the desirable purification effect.

1.2 Purification process by magnetic separation

Magnetic separation purification is mostly used to remove weak magnetic impurities such as pyrite and hematite. Magnetic separation is very environmentally friendly with no environmental pollution and no use of chemical agents, so it is widely used in many fields. Magnetic separation technology can effectively remove the weak magnetic impurity particles in kaolin, it effectively realizes the magnetic separation purification of non-metallic ore. Magnetic separator has also been improved with cutting-edge science and technology. Scientists have been able to control its speed of rotation to protect some parts from secondary pollution. It is believed that the development of magnetic separation technology will have a good effect on the purification process of kaolin in the future production.

The experiment shows that the finer the magnetic medium, the higher the field strength, the better the effect of iron removal, and as we all know that the quality of kaolin is negatively affected by its high iron content. Of course, magnetic sepration method and other methods together can do a better job in purification of kaolin.

2. application of Kaolin in ceramic refractory materials

The origin of the name "porcelain clay" is closely related to the porcelain industry. Data shows that it is still most widely used in the ceramic industry. The quality of ceramic products is closely related to the amount of kaolin resource. In order to produce ceramics with better strength, stability and other properties, it is necessary to use a certain amount of kaolin. Ceramics made with kaolin are of higher quality than ordinary ceramics in functions such as filters and water purifiers. Therefore, from this point of view, it is also necessary to increase the scientific research investment in kaolin purification and supply.

3. Our company

Gotray Refractory offers a comprehensive catalog of refractory ceramic finished products from plates, discs, rings, bars, rods, tubes, crucibles, saggers and customized shapes and parts. Materials are produced at our state-of-the-art facilities using injection and low-pressure injection molding, dry pressing, isostatic pressing, extrusion, slip casting, and sintering. Processing and machining capabilities include polishing, grinding, drilling, and precision milling via ball mills, bead mills, vertical spray dryers and horizontal spray dryers. Total process control allows us to manufacture materials in different temperature grades from 560 °C to 1800 °C and customize grain size, dimensional tolerance, porosity, and surface roughness with the highest dimensional accuracy of 0.0005 mm and surface roughness up to a mirror-polished effect.