Wollastonite is a naturally occurring metasilicate fibrous mineral with many excellent properties for industrial applications. Wollastonite is a high-quality ceramic raw material and metallurgical auxiliary; a high aspect ratio silica fume product can be used as a filler for plastics, rubber and paint coatings, and plays the dual role of reinforcement and increment. Wollastonite (CaSiO3 or Ca3[Si3O9]) is a chain metasilicate mineral, which has two variants of high temperature and low temperature. Generally speaking, wollastonite refers to β-CaSiO3. Wollastonite crystals develop along the {001} plane, the aggregates are fibrous, needle-like, bright white or white with light gray, light green, light red, glass or pearl luster, fibrous with silky luster; low oil absorption High electrical resistance, low dielectric constant, non-magnetic, low thermal expansion coefficient, excellent heat resistance, corrosion resistance, weather resistance and mechanical properties; chemically inert at low temperature, easy to mix with kaolinite, pyrophyllite, talc at high temperature Wait for the solid phase reaction to occur.

Industrial applications of wollastonite

Wollastonite products can be divided into two categories: high aspect ratio wollastonite and ground wollastonite. The former is widely used in plastics, rubber, asbestos substitutes, paints, coatings and other fields, and is the most promising application of wollastonite. field, the latter is mainly used in the ceramics and metallurgical industries.

as ceramic raw material

Wollastonite can be used to prepare various electric porcelain, architectural porcelain and daily-use porcelain, accounting for 40% to 45% of the total consumption. Wollastonite can densify the ceramic structure, improve the mechanical strength, reduce the expansion coefficient, improve the molding quality, reduce the firing temperature, shorten the firing cycle, and achieve the purpose of energy saving and efficiency. In the glaze industry, wollastonite can improve the whiteness of the glaze, improve the fluidity, and reduce the puncture of the product. Wollastonite can improve the thermal shock resistance of the green body, and the anorthite produced by the solid-phase reaction has a low melting point (1550°C), enabling rapid sintering at low temperatures. The microscopic wollastonite chain strengthens the connection between the glass phase particles, so that the product can withstand mechanical processing such as sawing and drilling, and also provides a low-loss insulating crystalline phase, which can be used as electrical and electronic ceramics.

Replacing glass fiber as a reinforcing material for plastics

Wollastonite for fillers has the characteristics of great potential, highest added value and fast growth. At present, wollastonite in this field accounts for about 25% of the total consumption. Wollastonite can replace or partially replace glass fiber as the reinforcement of polymer composites, improve material performance, reduce costs, and play the dual role of increment and reinforcement; its application research focuses on wollastonite reinforced composites in electronic components, Applications in packaging materials, high-performance rubber and plastic products, automotive casings, molds, and optical disc materials. The filling content of silane-modified wollastonite reinforced nylon reaches 50%, the impact strength is increased by more than 20 times, and it has a very low moisture absorption rate; high aspect ratio wollastonite and carbon fiber filled PTFE resin can be made into automatic sealing The ring body is used in the pressure reducing valve, butterfly valve and compressor repeating shaft.