Definition - What does Wollastonite mean?
This is a naturally occurring compound material - CaSiO3. It is characterized by its bright white color, but the color varies with the amount and type of impurities (gray-white, brown, red, etc.). It is also a deposit during the contact or regional metamorphism of skarn.
It is used as a reinforcement materials (plastics, paint films) and necessary in the production of ceramics. It is also used as a white pigment for aesthetics. Its improved physical properties (hardness, ductility, toughness, corrosion resistance and brittleness) make it a viable material in the ceramic, metallurgy, paint or coating, plastic and friction application industries.
Corrosionpedia explains Wollastonite
This material can be obtained in the laboratory by heating silica with limestone, but in normal occurrences it comes about from the direct crystallization from high-carbon magma. Deep burial and regional metamorphism assist in the crystallization of this material. Its composition comprises calcium, silicon and oxygen; however, there are small percentage traces of iron, aluminum, sodium and other elements.
Apart from dissolving in hydrochloric acid, its chemical reaction with other metals is inactive. Its high pH is useful in paints to stabilize acidity and reduce the breakdown of polyvinyl acetate. Its stability to high temperatures makes it a good replacement for asbestos for insulation purposes. It is useful in paints, adhesive, refractories, coatings and rubber production, and can be used as flux. Hence an important additive in polymerization processes.