What Is Fused Silica A Grade?

Fused Silica A Grade is produced by electrically fusing high-purity natural silica, followed by rapid cooling to prevent crystallization and ensure an amorphous glass structure.

With SiO₂ content ≥ 99.9%, this grade offers exceptionally low thermal expansion, outstanding thermal shock resistance, and high refractoriness, making it the preferred choice for demanding industrial applications.

Product Images

Fused Silica A Grade high purity material
Fused Silica A Grade – High Purity Material
Fused Silica A Grade 4-10 mesh
4–10 Mesh Coarse Grade
Fused Silica A Grade 20-50 mesh
20–50 Mesh Medium Grade
Fused Silica A Grade 50-100 mesh
50–100 Mesh Fine Grade
Fused Silica A Grade 200 mesh powder
200 Mesh Ultra-Fine Powder

Key Advantages of Fused Silica A Grade

  • Ultra-High Purity: ≥ 99.9% SiO₂, extremely low metallic impurities
  • Very Low Thermal Expansion: 5 × 10⁻⁷ /°C (20–700°C)
  • Excellent Thermal Shock Resistance
  • High Softening & Melting Temperature
  • Amorphous Structure (>99%): Minimal crystallization
  • Superior Chemical Stability & Acid Resistance

These properties make Fused Silica A Grade ideal for refractory, investment casting, and electronic-grade applications.

Chemical & Physical Properties

Chemical Composition (Typical Values)

Component Specification
SiO₂ 99.9% min
Fe₂O₃ ≤ 100 ppm
Al₂O₃ ≤ 200 ppm
Na₂O / K₂O ≤ 100 ppm each
MgO ≤ 200 ppm
CaO ≤ 100 ppm
Magnetic Impurities ≤ 50 ppm

Physical Properties

Property Value
Bulk Density 2.18 – 2.20 g/cm³
pH Value ~6
Melting Temperature 1750°C
Softening Temperature 1650°C
Thermal Expansion (20–700°C) 5 × 10⁻⁷ /°C

Available Sizes & Standards

ISO Sizes:

0–1 mm 1–3 mm 3–5 mm 3–6 mm 0.1–0.2 mm 0.2–0.5 mm 0.5–1 mm

ASTM Sizes:

4×10 Mesh 10×20 Mesh 20×50 Mesh 50×100 Mesh 140F 200F 325F

Custom particle size distribution available on request.

Mineralogical Structure

Phase Content
Amorphous Glass > 99%
Cristobalite / Crystalline Phase < 1%

The high amorphous content ensures zero or near-zero expansion behavior under extreme thermal cycling.

Applications of Fused Silica A Grade

Fused Silica A Grade is widely used in industries requiring thermal stability, purity, and chemical resistance:

Investment casting sand & flour
Fused silica crucibles for silicon ingot
Fused silica nozzles for steel industry
Furnace lining & ramming mass
Fused silica rollers for ceramic kilns
Monolithic castables for metal runners
Zero-expansion fused silica bricks
Electronic sealing materials (SLSI)
Epoxy fillers for electronics
Anti-acid applications in petrochemical

Packaging & Supply Options

  • 1000 kg / 1250 kg Super Sacks
  • 25 kg bags in big bags
  • 25 kg bags on pallets

Stable supply, consistent quality, and export-ready packaging for global markets.