Fused Silica Sand, Grains & Powder
Choose by form, grade and particle size. Every grade is visually sorted from the fused ingot, sized to your specification, and shipped with a COA that matches what you ordered.
Three forms, one controlled process
Grains, sand and powder come from the same graded ingot, processed on two dedicated lines — so chemistry stays consistent across every form you buy.
Fused silica Grains & Sand
Crushed and screened for refractory mixes, gunning and casting stucco.
- Mesh: 4-10, 10-20, 20-50, 50-100
- Millimetre: 0-1 mm, 1-3 mm
- Dust-free (classified) option for shell stucco
- Line: Barmac crusher → impact mill → long-screen → classifier
Fused silica Flour & Powder
Fine material for shell slurry, coatings, EMC and ceramic bodies.
- Mesh: 120, 200, 325 and finer
- -200 mesh, -325 mesh micro-powder
- PSD verified by Malvern (D10 / D50 / D90)
- Iron-free grinding — alumina-ceramic media & linings
Custom Specification
When your process needs a specific cut, we blend and re-check to it.
- Targeted PSD curves, custom mesh cuts
- Blending, re-weighing (+2%) and packing
- 25 kg bags / 1 t jumbo bags
- HS code 32074000 (sand & powder)
What Grade A, B and C actually mean — and why grading matters to your yield
Grading is visual and manual after the ingot cools: workers break it into 3-10 cm pieces and sort by transparency, black spots and cristobalite. Machine vision cannot reliably separate the defects that change end-use performance, so this step stays human. The result: the grade you pay for is the grade you get.
- Fully transparent
- No black spots, no cristobalite
- 1-2 cloudy lines acceptable
- Minor black spots
- Thread-like black lines possible
- Larger black lines or patches
- May contain cristobalite pieces (C-/D)
Grade A vs. the industry baseline — guaranteed specs compared
Most fused silica datasheets guarantee SiO₂ ≥99.7% and Fe₂O₃ ≤350 ppm. We guarantee tighter — and publish the actual SGS test result on every batch COA. The comparison below is guaranteed-spec vs guaranteed-spec; ask any supplier for their actual batch results and compare.
| Parameter | Typical international industry baseline | Chemsize Grade A |
|---|---|---|
| SiO₂ | ≥ 99.7% | > 99.9% TIGHTER SPEC up to 99.96% by some laboratories |
| Fe₂O₃ | ≤ 350 ppm | < 50 ppm TIGHTER SPEC 41 ppm typical, 31 ppm best batch (SGS) |
| Na₂O | Not typically disclosed | 24-27 ppm 80× BELOW THRESHOLD ~2200 ppm catalyses cristobalite transformation |
| Amorphous content | Not uniformly disclosed | > 99% (SGS) |
| Powder grinding | Al₂O₃ pickup up to 3000-4000 ppm disclosed for some powders | Iron-free: alumina-ceramic media & linings, controlled pickup |
* Baseline figures are guaranteed specs published on leading international datasheets — not actual batch results. Their actual tested values may be lower than what they guarantee, just as ours are (we guarantee <50 ppm, test at 41 ppm). SiO₂ figures vary with test method and laboratory; we state the method and lab with every COA. The real differentiator isn't just the spec — it's that we publish actual SGS results per batch and invite you to compare.
Iron-free grinding: Fe₂O₃ on the COA is Fe₂O₃ in your batch
Powder is ground in a ball mill with alumina-ceramic grinding media and alumina-ceramic linings. No steel contact means iron is not added back during processing — the chemistry of the ingot carries through to the final powder.
Every batch then passes the finishing plant's 12-step QC engineering table: blending, re-weighing (+2%), sieving checks and final packing. Before shipment, every batch is sampled and tested — XRF/ICP chemistry, Malvern PSD plus standard sieves, whiteness, pH, moisture — and the COA matches your purchase specification.
Quick answers buyers ask before specifying
How are grades A, B and C distinguished?
Manually by visual inspection after cooling — transparency, black spots and cristobalite. Grade A is fully transparent, no black spots, no cristobalite; B has black spots or thread-like lines; C has larger patches and may carry cristobalite. This step is manual because machine vision cannot reliably tell the defects apart.
What mesh sizes can you supply?
Standard foundry/refractory fractions such as 30-50, 50-100 and 100-200 mesh, plus fine powders like -200 and -325 mesh. Sizes are matched to your specification and confirmed by standard sieves and Malvern PSD analysis.
What does "dust-free" sand mean?
The sized sand is passed through a classifier that pulls out fine dust — required by investment foundries for stucco and slurry, because dust disturbs shell quality. It is not a clean-room step at the melting stage.
Do you test every batch before shipment?
Yes. Every batch is sampled and tested before shipment, and we issue a COA matching your purchase specification — not spot-checked, not once a month.
What is the HS code for fused silica sand and powder?
HS 32074000 covers fused silica in sand, grain and powder form.
How is fused silica packaged for export?
25 kg woven plastic bags inside a 1 t jumbo bag on a wooden pallet — or 25 kg bags palletized for LCL. Packing can be tailored to your specification. A 20' FCL holds 27 t max. We do not normally use 40' FCL for fused silica.
Do you offer free samples?
Yes. We provide 1-2 kg trial samples for qualified buyers; courier cost is collect. The sample COA shows typical chemistry and PSD for the requested grade and mesh.
Tell us your mesh, grade and volume
We'll confirm the PSD, chemistry target and lead time, and send a COA-matched quotation.
Request a Specification