Different applications and specifications of washed kaolin and calcined kaolin

Release time:

2024-01-31 14:44

Kaolin is a non-metallic mineral, which is a kind of clay and clay rock mainly composed of kaolinite clay minerals. Because it is white and delicate, also known as white earth. It is named after Gaoling Village, Jingdezhen, Jiangxi Province.

Its pure kaolin is white and delicate, soft soil, with good plasticity and fire resistance and other physical and chemical properties. Its mineral composition is mainly composed of kaolinite, halloysite, hydromica, illite, montmorillonite, quartz, feldspar and other minerals.

Kaolin is divided into washed kaolin and calcined kaolin.



the difference between washed kaolin and calcined kaolin:

First, the calcined kaolin is calcined, and the crystal form and the original soil have been changed. However, the washed kaolin is only physically treated and will not change the original soil properties.

Secondly, the difference in whiteness is relatively large. Generally, the whiteness of kaolin will increase after light burning, while washing will not significantly increase the whiteness.

Third, the purpose is different. Depending on the calcination temperature, kaolin can be used as a papermaking additive and refractory aggregate. The washed kaolin is generally used as a papermaking filler.

At present, calcined kaolin mainly refers to hard kaolin (coal series kaolin). The original soil has no cohesiveness and cannot be directly used as raw materials for papermaking or refractory materials. It needs to be calcined and applied after calcination. The original soil of washed kaolin has cohesiveness and can be directly used as refractory binder or papermaking filler.

As a papermaking filler, the whiteness of calcined kaolin is much better, and the cost is also relatively high.

Calcination will also lead to the increase of kaolin particle size, although the specific surface area decreases, the adsorption decreased, but the surface energy decreased, so that the kaolin dispersion is improved, and no fixed structure becomes loose, can also improve the dispersion. Calcined dehydroxylated kaolin is usually refined by grinding or chemical surface modification as a reinforcing filler for rubber, plastics and the like to partially replace white smoke.



Product use:

1. Washed kaolin has become a necessary mineral raw material for papermaking, ceramics, chemical industry, glue, adhesive, national defense and other industries;

Ceramic industry is the application of kaolin early, large amount of industry. The general dosage is 20% to 30% of the formula. The role of kaolin in ceramics is the introduction of Al2O3, is conducive to the formation of mullite, improve its chemical stability and sintering strength, in the firing of kaolin decomposition of mullite, the formation of the main framework of the green body strength, can prevent the deformation of the products, so that the firing temperature widened, but also can make the body with a certain degree of whiteness. At the same time, kaolin has a certain plasticity, adhesion, suspension and binding capacity, giving porcelain mud, porcelain enamel good formability, so that ceramic mud billet is conducive to car billet and grouting, easy to form.

2. Calcined kaolin is widely used in ceramics, rubber, plastics, coatings, artificial leather, self-cement, refractory materials, cosmetics, etc. With the further improvement of the mineral processing technology of kaolin, the application range of kaolin will be more and more extensive. The coal geological system preparation unit can be based on the actual situation, based on the kaolin resources and market demand in the coal measure strata. Kaolin is a non-metallic mineral that is ubiquitous in nature. In the past, it was generally used to produce ceramics, refractory materials, and a small amount of fillers mixed with plastics and rubber.

Calcined kaolin has the characteristics of high whiteness, strong hiding power, good fluidity, high oil absorption and good suspension in coatings. The performance of the coating and coating obtained by adding this fine calcined kaolin to the latex paint will make us feel that kaolin is not only an ordinary filler, it can become a functional filler to improve the quality of the coating.

Calcined kaolin in rubber and special cable reinforcing agent, industrial plastic function filler, ink filler.

Calcined kaolin can replace part of the expensive titanium dioxide in paper coating.

Kaolin, calcined, filler, paper, washing, can, refractory, as,

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