Wollastonite

One of the most versatile fillers in the marketplace

Wollastonite is a naturally occurring mineral that is a chemical combination of calcium, silicon and oxygen. Wollastonite is formed when limestone or other high-calcium rocks undergo high temperature and pressure changes sometimes in the presence of silica-bearing fluids such as in skarns or contact metamorphic rocks.

This highly versatile mineral is characterized by its high whiteness, unique needle-like, or ‘acicular’, structure, high brightness, low moisture and oil absorption, and high heat stability. Imerys engineers these properties to meet the needs of the plastics, paints, ceramics, friction products, construction materials, and adhesives & sealants producers.

Physical properties

• High brightness
• Low moisture and an oil absorption
• Low water solubility
• High pH
• Low volatile content
• High melting point
• Medium hardness (4.5 on Mohs’ scale)
• Thermal stability

World leader in wollastonite production 

Imerys is a world leader in wollastonite production for paints, plastics and ceramics. Our Pilares wollastonite mine in Hermosillo, northwestern Mexico, yields high-quality ore to serve customers worldwide. 

Using advanced processing techniques our specialists are able to achieve the exact level of acicularity our customers require, including premium high aspect ratio products for various high-end applications.

Engineered grades for high value-added markets 

Imerys essentially focuses its attention on engineered and surface-treated grades for high-value-added markets such as automotive plastics and paints and coatings.

Used in the plastics industry, wollastonite is a cost-effective replacement for fibreglass, milled carbon fibre and synthetic materials. It is particularly prized by the automotive industry as it improves the strength, dimensional stability and impact resistance of car parts, enabling manufacturers to make them lighter. It also boosts the scratch resistance of parts and improves weld line strength. In Electrical and Electronic (E&E) parts such as computer housings and electrical connectors, wollastonite enhances insulating properties and fire resistance. 

Used in paints and coatings, Imerys engineered wollastonite grades provide flexibility, excellent anti-cracking, mechanical reinforcement and impact resistance, as well as gloss control properties thanks to its unique morphology and hardness. In industrial coatings, Imerys wollastonites provide good anti-corrosion properties and optimal mechanical performance in terms of hardness, adhesion, impact and flexibility, without impacting gloss level. Thanks to its low oil absorption, Wollastonite can be used in low viscosity systems resulting in lower VOC levels. Wollastonite is ideal for the marine and protective coatings, wind turbine, automotive, aerospace and pipe coatings.  

Our ceramics grades increase the green and fired strength of ceramic tiles and sanitaryware bodies and reduce crazing, cracking, and glaze defects. They enable ceramics manufacturers to speed up firing, reducing energy costs and CO₂ emissions. 

Used in the construction industry, Imerys wollastonites are excellent lightweight reinforcing fillers for cement boards and fire-resistant insulating boards. They bring numerous benefits to fibre-reinforced concrete.

Image

With demand for ultrafine grades for automotive plastics on the rise and steady growth forecast for all its end-user segments, the global market for wollastonite looks promising indeed. And with reserves at our Mexican wollastonite operations until well into the 22^nd century, Imerys is all set to lead the way.