Five application fields and characteristics of wollastonite
However, most of wollastonite are white, and very few are yellow, green, brown and other colors. Pure wollastonite is white or bright white with vitreous luster. The purity of wollastonite with the highest purity can reach 99%, and the reflectivity of wollastonite with a particle size of less than 44 μm can reach 92~96%, so it has high whiteness. . These valuable process characteristics are widely used in high-grade ceramic products, high-quality white paints or glossy coatings. The ultra-fine acicular wollastonite powder can replace other short-fiber mineral materials and synthetic crystals as functional reinforcing materials, and has extremely high application value in industry.
Ceramics
Wollastonite is widely used in the ceramic industry, accounting for about 50% of the total domestic use. In the ceramic industry, wollastonite is mainly used to produce art porcelain, sanitary porcelain, glazed tiles, electric porcelain, daily-use porcelain and chemical ceramics. Because the grade of wollastonite is usually about 80%, the whiteness of natural wollastonite is also very high, which is very suitable to replace the mixture of SiO2 and CaO in ceramic glaze, and use wollastonite as the mixture of ceramic glaze The fired ceramic has a very smooth and smooth glaze.
Rubber
The application research of wollastonite in the rubber industry has been carried out earlier in China. It can largely replace titanium dioxide, clay and lithopone in light-colored rubber, play a certain reinforcing role, and can improve the covering ability of white colorants. Play a whitening effect. After the organic modification of wollastonite, not only its surface has lipophilicity, but at the same time, due to the double bond in the molecule of sodium oleate of the treating agent, it can participate in vulcanization, enhance cross-linking, and the reinforcing effect is greatly improved.
In the coating industry, wollastonite powder can be used as an extender pigment to replace a certain amount of white pigments such as titanium dioxide, because wollastonite powder has high surface gloss, good waterproof and aggressiveness, and low cost, which can increase the coating film. thickness and adjust coating rheological properties.
Papermaking
The application of wollastonite in the paper industry is quite different from other fillers. It is not a simple filling like traditional fillers, but mainly relies on a higher aspect ratio to realize the interweaving of wollastonite and plant fibers to form plants. The mesh structure of fiber-mineral fiber can effectively improve the opacity and printing adaptability of the produced paper, improve the uniformity, and reduce the manufacturing cost to replace some short fibers of plants.
Plastic
In the plastics industry, wollastonite’s high electrical resistance, low dielectric constant and low oil absorption make it a distinct advantage over other non-metallic mineral materials. The compatibility of the modified wollastonite with plastics is greatly improved, and the needle-like crystal shape that it maintains after crushing can improve the properties of plastics and ensure that the products have high thermal stability, low dielectric Electrical properties, low oil absorption and high mechanical strength, while reducing the cost of the product. Nylon is one of the largest markets for wollastonite applications. Wollastonite reinforced nylon 6 or nylon 66 after modification with silane coupling agent can improve bending strength and tensile strength, reduce moisture absorption rate and improve dimensional stability.