Chromite sand is a naturally occurring spinel consisting primarily of the oxides of chrome and iron. It is a by-product of ferro-chrome production and is mainly used in foundry applications and in glass production.
Chromite Flour Core Properties
- Melting point: ~2180℃, high refractoriness
- High thermal conductivity, good chemical inertness against molten steel/iron
- Low thermal expansion, dense packing, anti-metal penetration & anti-burn-on
- Hard & wear-resistant; forms a compact refractory barrier layer on coating surface
Mesh / Particle Size
- 200 mesh: max 75μm, for brushing & dipping coating; heavy-section steel castings, ingot moulds, water-based refractory coating. Good suspension, cost-effective general grade
- 325 mesh: max 45μm, mainly for spraying coating; alloy steel, manganese steel, stainless steel, lost foam refractory coating. Most popular grade for fine smooth coating surface
Standard Chemical Spec (Foundry / Refractory Coating Grade)
| Item | Standard |
|---|---|
| Cr₂O₃ | ≥46.0% |
| SiO₂ | ≤1.0% (critical, high silica causes coating erosion) |
| CaO | ≤0.30% (prevent blistering & cracking) |
| P, S | ≤0.003% (avoid casting porosity) |
| Moisture | ≤0.1% |
| Cr/Fe ratio | ≥1.55 |
Application for Refractory / Foundry Coating
- Works as refractory filler/aggregate in water-based or alcohol-based mould coating
- Main functions: anti-burn-on, anti-sand sticking, heat conduction, improve casting surface finish
- Also used as raw material for magnesia-chrome refractory castable, magnesia-chrome bricks