Industrial Mineral · Acicular Calcium Silicate

Wollastonite

硅灰石 · Calcium Metasilicate (CaSiO₃)

Acicular (needle-like) · Aspect ratio 3:1 to 20:1

Wollastonite is a naturally acicular calcium silicate prized for its needle-like crystal habit, low moisture and oil absorption, high brightness and fluxing behaviour. It reinforces and functionalises ceramics, polymers, friction materials, paints and welding consumables.

At a Glance

FormulaCaSiO₃
CaO~46%
SiO₂~52%
Aspect Ratio3:1 to 20:1
GradesH-series / Y-series
FOB China$200–500 / MT

Product Overview

Wollastonite is a calcium metasilicate (CaSiO₃) with a distinctive acicular, or needle-like, crystal structure. That natural fibre shape, combined with low moisture and oil absorption, high brightness, alkaline pH and excellent thermal stability, makes it a multifunctional industrial mineral used as both a filler and a reinforcement.

High-aspect-ratio (Y-series) grades act as a functional reinforcement — improving flexural and impact strength in engineering polymers (a partial replacement for glass fibre and asbestos), and giving green strength and dimensional stability in friction materials such as brake pads and clutch linings. Lower-aspect (H-series) milled grades serve as fluxing and brightening additives.

In ceramics, wollastonite lowers firing temperature and shrinkage, reduces moisture expansion and speeds fast-fire cycles for tiles and sanitaryware. In paints it acts as a TiO₂ extender and anti-corrosion pigment, and in welding electrodes/fluxes it provides a stable arc and good slag detachability. Global Vista supplies acicular wollastonite from Chinese and Korean sources across the H-800/H-1250/H-1800 and Y-800 range.

Technical Specifications

ParameterTypical / Guaranteed Value
Calcium Oxide (CaO)~45–47%
Silicon Oxide (SiO₂)~50–53%
Iron Oxide (Fe₂O₃)≤ 0.5%
Loss on Ignition≤ 2%
Whiteness85–92%
Aspect Ratio3:1 to 20:1 by grade
pH (aqueous)~9.9
Moisture≤ 0.5%
GradesH-800, H-1250, H-1800, Y-800

* Values are indicative typical/guaranteed figures and can be tailored to your specification. A Certificate of Analysis (COA) is delivered with every shipment; third-party inspection (SGS / Bureau Veritas / Intertek / CIQ) available on request.

Grades

Y-800

High aspect

Needle-rich reinforcement grade for polymers and friction materials.

Common: polymer / friction

H-800

Coarse milled

General filler and flux for ceramics and coatings.

Common: ceramics

H-1250

Fine

Fine functional filler for paints, plastics and ceramics.

Common: paint / plastics

H-1800

Ultra-fine

High-performance filler for premium coatings and engineering polymers.

Common: premium coatings

Applications

Welding Electrodes & Flux

Supplies calcium and silica for a stable arc, good slag formation and clean detachability in welding consumables.

Friction Materials

Reinforces brake pads, linings and clutches — provides green strength, thermal stability and is an asbestos-free fibre alternative.

Ceramics & Tiles

Lowers firing temperature and shrinkage, reduces moisture expansion and enables fast-fire cycles for tiles, sanitaryware and glazes.

Polymer Reinforcement

Acicular grades improve flexural strength, HDT and dimensional stability in PA, PP and engineering plastics — partial glass-fibre replacement.

Paints & Coatings

Functions as a TiO₂ extender, anti-corrosion pigment and flatting/reinforcing filler with low oil absorption and high brightness.

Fireproofing & Construction

Calcium-silicate boards, joint compounds and fireproofing where thermal stability and low shrinkage matter.

Quality Assurance

  • Certificate of Analysis (COA)

    Lot-traceable chemical and physical analysis with every shipment.

  • Third-Party Inspection

    SGS, Bureau Veritas, Intertek or CIQ pre-shipment inspection on request.

  • Customer Sample Review

    Pre-shipment sample for your lab verification before bulk order.

  • Specification Matching

    Grade and granulometry tailored to your process, not sold as a generic commodity.

Logistics

  • Origin Ports

    Tianjin Xingang · Qingdao · Shanghai

  • Packaging

    25kg paper/PP bags (palletized) or 1 MT jumbo bags. Sealed liners for fine grades.

  • Incoterms

    FOB, CIF, CFR, DAP available.

  • Payment Terms

    T/T or irrevocable L/C at sight. USD / EUR / JPY settlement.

  • Lead Time

    15–25 days from order confirmation to vessel sailing.

Frequently Asked Questions

What is wollastonite used for?

Wollastonite is a multifunctional calcium-silicate mineral used in ceramics (lowers firing temperature/shrinkage), friction materials (brake pads), polymers (reinforcement and glass-fibre/asbestos replacement), paints (TiO₂ extender, anti-corrosion) and welding consumables (flux).

What is the difference between H-series and Y-series grades?

Y-series grades retain a high acicular (needle) aspect ratio for reinforcement in polymers and friction materials. H-series grades are milled to specific finenesses (H-800/1250/1800) for use as functional fillers and fluxes in ceramics, paints and plastics.

Is wollastonite a safe asbestos alternative?

Wollastonite is a naturally occurring calcium silicate widely used as an asbestos-free functional fibre in friction and reinforcement applications. We can supply documentation on grade composition for your compliance review.

How does wollastonite help ceramics?

Its CaO–SiO₂ chemistry acts as a flux that lowers firing temperature and energy use, while the low loss-on-ignition and needle structure reduce shrinkage, warping and moisture expansion — enabling faster firing of tiles and sanitaryware.

What aspect ratios are available?

From roughly 3:1 for milled filler grades up to 15–20:1 for high-aspect reinforcement grades. Specify your target aspect ratio and fineness and we will match the closest standard grade.

What is the minimum order quantity?

Trial orders from a few MT (one pallet to one container). Production and contract volumes per customer specification, with COA included.

Request a Quote

Specify your grade/size, quantity and destination port — we respond within one business day with FOB China and CIF quotes.

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