Main uses of Wollastonite
The needle like crystal of wollastonite provides a channel for the rapid discharge of water from the green slab, and the drying speed is accelerated, so it is easy to be pressed and formed without layering. During calcination, the unmelted residue of wollastonite needle forms a dense skeleton to prevent the volume change of the body. When the body is cooled, the needle between them is firmly bonded by sinter crystallization. The green body has porous and network structure. The low coefficient of thermal expansion and linear expansion of wollastonite are beneficial to the thermal shock resistance of the green body.
The United States, the former Soviet Union and other countries have done a lot of research work on the application of wollastonite in glazed tiles. The annual output of wollastonite in the United States is about 60000-70000t, half of which is used in the production of glazed tiles. The glazes brick with wollastonite as the main raw material can save about 30% - 50% of fuel, which is known as the energy-saving raw material.
In metallurgical industry, wollastonite is mainly used to produce mold casting slag and slab casting slag. The wollastonite based slag developed by Wuhan Iron and Steel Research Institute can replace the "float 40" slag imported from Japan. The powder and granular mold powder based on natural wollastonite has the characteristics of very stable chemical properties and low Al2O3 content, which can stabilize the continuous casting operation and improve the quality of continuous casting slab.
Wollastonite, as the coating material of welding electrode, has been applied in the welding industry, especially suitable for manufacturing high titanium low carbon steel welding electrode. Wollastonite powder and ultrafine powder are used as fillers and coatings in plastics, rubber, paper and paint industries, which not only reduces the cost of products, but also improves the physical-chemical properties, especially the mechanical properties of products. It is predicted that the consumption of wollastonite and ultrafine powder for industrial fillers and coatings will increase by 10% every year.