Wollastonite: The High-Performance Acicular Mineral

Wollastonite  is a naturally occurring calcium metasilicate mineral known for its unique needle-like  crystal structure.

As a versatile inorganic functional filler, it is prized for its high brightness, low moisture absorption, and exceptional mechanical reinforcement properties. It serves as a superior asbestos alternative and a key performance enhancer in high-end industrial manufacturing.

1. Production Processes (Two Routes)

（1）Physical Acicular Preservation Method

Uses high-purity wollastonite ore; utilizes specialized non-destructive crushing and air-jet milling to maintain the high aspect ratio (length-to-diameter ratio) of the needles. Suitable for plastics, friction materials, and high-strength construction boards.

（2）Ultrafine Grinding & Surface Modification

Processes ore into 325-2500 mesh powder followed by coupling agent treatment (silane/titanate). This enhances compatibility between the inorganic mineral and organic polymers. Ideal for high-end coatings, automotive plastics, and specialized rubber seals.

2. Core Features

（1）High Aspect Ratio & Reinforcement: The needle-like crystals act as "micro-steel bars," significantly improving the tensile strength, impact resistance, and dimensional stability of composite materials.

（2）Low Thermal Expansion & Heat Resistance: Melting point ~1540℃; features a very low coefficient of thermal expansion, effectively preventing shrinkage and warping in high-temperature applications.

（3）Excellent Dielectric Properties: Low dielectric loss and high electrical insulation, making it a preferred filler for electronic packaging and high-frequency circuit components.

（4）Chemical Inertness & Alkaline pH: Naturally maintains a pH of 8–10, which acts as a buffer in coatings to prevent corrosion and improve the shelf life of water-based systems.

3. Application Industries

（1）Plastics and Rubber

Widely used in automotive parts (bumpers, dashboards) and nylon modification; replaces glass fiber to reduce costs while maintaining mechanical integrity and surface smoothness.

（2）Coatings and Construction

Enhances the durability and scrub resistance of architectural coatings; serves as a reinforcing filler in fireproof boards and fiber-cement sheets due to its non-combustible nature.

（3）Ceramics and Friction Materials

Reduces firing temperatures and prevents cracking in ceramic glazes; replaces asbestos in brake pads and clutch linings to provide stable friction coefficients and low noise.

4. Procurement Standards

Qualifications: Comply with ISO 9001; REACH/RoHS certified for EU export. Specific grades must be Asbestos-Free (certified by XRD testing).

Recommendations: Prioritize suppliers with high-quality mineral veins to ensure consistent needle morphology; conduct oil absorption and mesh residue tests before bulk transition.