Fused silica you can run without surprises — batch after batch.
Casting shells cracking at dewaxing? Refractory linings failing under thermal shock? Fe₂O₃ drifting and ruining your EMC or ceramic properties? Chemsize supplies fused silica with fixed chemistry, controlled particle size and a COA on every batch — so your process gets the same material, every time.
Three problems in your line — three ways our material prevents them
We do not sell chemistry on paper. Every specification below is tied to a failure it prevents in your production.
Fused silica's near-zero thermal expansion comes from its amorphous structure. We hold >99% amorphous on Grade A (SGS-verified) and grade out cristobalite-rich material by hand — so your shell or lining behaves predictably at high temperature.
Powder is ground with alumina-ceramic media and linings, not steel. Iron is not added back during processing, so the Fe₂O₃ on the COA is the Fe₂O₃ in your batch — stable for ceramics, EMC and CCL applications.
Raw material comes from the same Donghai quartz lump source, every furnace run. Every batch is sampled and tested before shipment, and the COA matches your purchase specification — fewer surprises, less re-qualification.
Fused silica in the form your process actually needs
From coarse grains for refractory gunning to ultra-fine powder for shell slurry — graded, sieved and blended to your specification.
Grains & Sand
Angular fused silica for refractory mixes and casting applications.
- Mesh: 4-10, 10-20, 20-50, 50-100
- Millimetre: 0-1 mm, 1-3 mm
- Dust-free option (classified) for shell stucco
- Custom cuts available
Flour & Powder
Fine fused silica for shell slurries, coatings and ceramic bodies.
- Mesh: 120, 200, 325 and finer
- Controlled PSD — D10 / D50 / D90 by Malvern
- Iron-free grinding keeps Fe₂O₃ low
Custom Specification
Particle size, chemistry target and packaging matched to your process.
- Targeted PSD curves
- 25 kg bags / 1 t jumbo bags
- COA and third-party testing on request
Industries that buy fused silica — and why
Refractories
Bricks, castables, ramming mixes and ceramic welding. Low thermal expansion means linings survive more heat cycles — fewer shutdowns, longer service life.
Investment Casting
Slurry and backup stucco for ceramic shells. High amorphous content and low alkali give clean dewaxing and shell removal — fewer rejects at knockout.
Technical Ceramics
Crucibles, rollers, tubes and precision parts. Low Fe₂O₃ and alkali keep color, electrical and thermal properties stable through firing.
Real numbers. No blending of rejected material. A COA you can trust.
Fused silica is made in three-phase electric arc furnaces at 2200–2500 °C from Donghai quartz lump — the same ore body that built China's fused-silica hub. Only about 80% of each 20-tonne melt becomes acceptable Grade A/B material; we reject or downgrade the rest instead of blending it into your shipment.
Chemsize works with two partner plants (Donghai Hecheng ~10 kt/y, Jiangsu Xinda ~20 kt/y) as a specialised trading company that enforces batch testing and export documentation — you get factory-direct material with trader-grade service.
Technical notes and shipping updates
We publish short, practical notes on fused silica specification, shell-room practice and supply updates.
Why precision-casting shell rooms keep buying fresh fused silica
Shells are single-use: above ~900 °C fused silica transforms to cristobalite and the shell is scrapped. Reclamation is nearly impossible — sodium impurity accelerates the transformation. The result: structural, recurring demand for fresh, low-alkali, high-amorphous material.
How to read a fused silica COA — what actually matters
SiO₂ number, Fe₂O₃, amorphous content, PSD: which values decide whether your batch will run? What we test on every batch (XRF/ICP, Malvern, sieves, whiteness, pH, moisture) and why.
Specify your fused silica — we'll quote with COA and lead time
Tell us your mesh size, application and annual volume. We'll confirm the grade, particle-size distribution and delivery schedule — no obligation.
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