composition | material | ||||||||||
Ordinary Alumina ball | low Alumina ball | Medium Alumina ball | high Alumina ball | 99% Alumina ball | |||||||
feldspathic | Feldspathic-mullite | mullite | Mullite- | corundum | |||||||
chemical composition% | Al2O3 | 20-30 | 31-45 | 46-70 | 71-90 | ≥90 | |||||
Al2O3+SiO2 | ≥90 | ||||||||||
Fe2O3 | ≤1 | ||||||||||
water absorption % | ≤5 | ≤8 | |||||||||
Mohs' hardness grade | 7 | 7 | 7 | 7 | 7.5 | ||||||
Acid resistance % | ≥98 | ||||||||||
Alkali resistance % | ≥80 | ≥82 | ≥85 | ≥90 | ≥95 | ||||||
heat resistance ℃ | 1000 | 1200 | 1300 | 1400 | 1500 | ||||||
compressive strength KN/pcs | Φ3mm | ≥0.20 | ≥0.25 | ≥0.30 | ≥0.35 | ≥0.40 | |||||
Φ6mm | ≥0.50 | ≥0.6 | ≥0.65 | ≥0.70 | ≥0.80 | ||||||
Φ8mm | ≥0.70 | ≥0.8 | ≥0.90 | ≥1.00 | ≥1.20 | ||||||
Φ10mm | ≥0.85 | ≥1.0 | ≥1.20 | ≥1.50 | ≥1.90 | ||||||
Φ13mm | ≥1.80 | ≥2.30 | ≥3.00 | ≥4.00 | ≥5.80 | ||||||
Φ16mm | ≥2.30 | ≥3.00 | ≥4.50 | ≥6.00 | ≥7.00 | ||||||
Φ20mm | ≥4.30 | ≥5.00 | ≥6.00 | ≥7.50 | ≥9.00 | ||||||
Φ25mm | ≥6.20 | ≥7.00 | ≥8.00 | ≥10.00 | ≥12.00 | ||||||
Φ30mm | ≥7.00 | ≥8.00 | ≥10.00 | ≥12.00 | ≥14.00 | ||||||
Φ38mm | ≥8.80 | ≥10.00 | ≥12.00 | ≥16.00 | ≥18.00 | ||||||
Φ50mm | ≥12.00 | ≥13.00 | ≥15.00 | ≥18.00 | ≥21.50 | ||||||
Φ76mm | ≥16.00 | ≥18.00 | ≥20.0 | ≥22.00 | ≥25.00 | ||||||
Bulk density kg/m3 | 1300--1400 | 1400-1500 | 1500-1600 | 1600-1800 | ≥1800 |