Calcined kaolin is an industrial mineral that is used in paint, plastic, rubber, polymer, paper and adhesive industries.calcined kaolin It is produced by exposing natural kaolin to high temperatures to improve its optical and physical properties. The calcination process increases whiteness, hardness and electrical properties while altering the size and shape of the kaolin particles.
The calcination process involves heat treatment of the raw kaolin in a rotary kiln.calcined kaolin This thermal processing device is extremely flexible and can be configured to meet a variety of conditions.
This process is used to produce a range of kaolin products including kaolin pozzolana (pozzolana kaolin), kaolin pigments, alumina sources for the production of fiberglass and surface modified clays.
pozzolanic materials are commonly used in the construction industry for applications such as concrete and cement where they provide improved mechanical properties, porosity and appearance. They also offer a cost effective means of enhancing the performance of cement-based materials.
Imerys offers a wide variety of reactive and calcined kaolin pozzolana, providing a highly functional and cost-effective solution to the needs of our customers. These kaolins are engineered to enhance the performance of our end-products, allowing our customers to reduce costs and improve their sustainability and environmental impact.
Glazes are a key application for kaolin. They are a natural source of AlO and SiO that all glazes need to work properly, as well as acting to suspend the dry layer of glass or other material. However, a small percentage of the kaolin in raw recipes causes shrinkage when glazed, due to its chemistry. Substituting part of the raw kaolin for calcined kaolin solves this problem, maintaining the chemistry of the glaze but reducing the shrinkage and cracking.
The calcination process can be performed using a rotary kiln or muffle furnace. The kiln is the preferred process for most applications. The muffle furnace provides a lower temperature and allows for the heating of the calcined kaolin for a longer period of time than a rotary kiln, resulting in better control over the calcination process and improved kiln productivity.
In the ceramics industry, kaolin is widely used to manufacture sanitaryware, tableware, wall and floor tiles, and refractories. It is also a critical component in ceramic catalyst supports and diesel particulate filters.
Kaolin is an essential ingredient for the production of refractory materials, where it can be used to improve the strength and ductility of metal and ceramic parts. It is also used in a wide range of other products, such as ceramic coatings, paints, dyes and pigments.
Agricultural films are another key application for kaolin. It can be used as a functional extender to replace titanium dioxide in the formulation of paints, giving desirable flow properties and reduced pigment consumption. It is also used as an antiblock additive, improving the thermal properties of agricultural film and enabling it to be re-heated more frequently.
Calcined kaolin is an important extender for paints, particularly in a low cost formulation that requires high opacity and print-through resistance. It is chemically inert, has a high covering power, gives desirable flow properties and is less expensive than many of the other extender pigments that are available. It also provides a harder paint film than titanium dioxide, which is beneficial in terms of durability and burnish resistance.
0users like this.