 White fused alumina (high purity with Al₂O₃ content over 99%) is produced from high purity alumina in electric arc furnaces at temperatures over 2000℃ under carefully controlled conditions.  White fused alumina is also characterized by high hardness of mohs 9, the chemical stability at very high temperatures, great self-sharpening, superior acid and alkali resistance, and stable thermal performance.  Physical Index: True density 3.96g/ cm³ Hardness 2000~2200kg/ mm² Refractoriness ≥1850℃ Max useable temperature 1900℃  Chemical composition:  Al₂O₃ ≥99.20 and Na₂O≤0.40 in F12-220;  Al₂O₃≥99.00 and Na₂O≤0.50 in F230-400;  Al₂O₃≥99.00 and Na₂O≤0.50 in F500-1200;