The inert alumina ceramic ball is broadly utilized as the covering or supporting materials of the catalyst in the reactors and the packing in the columns in such varied areas, for example, petroleum, chemical industry, chemical fertilizer, natural gas, and environmental protection etc. There are lots of merits for it, for instance, the stronger resistance to high temperature and high pressure, lower ratio of the moisture absorbing, more stable chemical properties, and so on. It is capable of enduring the corrosion of acid, alkali, and organic solvent. In addition, it can also bear the rapid transitions of temperature during the operation. In fact, its principal functions are to accelerate the distribution of gas or liquid, and support or protect the active catalyst, which especially has the relevantly lower mechanical strength. Chemical Compositions Chemical compositions Content Al2O3 (Standard value +4) % Al2O3+SiO2 ≥92% Fe2O3 <1% Physical and chemical properties Main crystal phases Al2O3 Property Feldstar Feldstar-mullite Mullite Mullite-corundum Corundum 20-25 25-45 45-70 70-90 >90 Bulk density, (g/cm3) 1.3-2.0 Water sorption, （%） <3 <1 Acid resistance（%） >98 Alkali resistance（%） >80 >82 >85 >90 >95 Spalling resistance（℃） >250 >300 >500 >700 >800 Refractoriness(℃) >1300 >1400 >1500 >1600 >1700 Crushing strength, KN/particle ?6 >0.40 >0.45 >0.6 >0.7 >0.8 ?8 >0.7 >0.8 >0.9 >1.0 >1.2 ?10 >0.9 >1.0 >1.2 >1.5 >1.8 ?13 >1.2 >1.3 >1.6 >1.8 >2.0 ?16 >1.5 >1.6 >1.8 >2.3 >2.6 ?20 >1.8 >2.0 >2.3 >2.8 >3.20 ?25 >2.5 >2.8 >3.2 >3.6 >4.0 ?30 >2.8 >3.0 >3.5 >4.0 >4.5 ?38 >4.0 >4.5 >5.0 >5.5 >6.0 ?50 >6.0 >6.2 >10.0 >10.5 >11.0 ?60 >8.0 >8.5 >11.0 >12.0 >14.0 ?75 >13.0 >11.0 >12.0 >14.0 >15.0 Note: It may only be provided as the reference for the bulk density, and it is not as the evidence of check. Main specifications and types a) Specifications and allowable deviation of diameter　 Unit：mm Diameter? 3 6 8 10 13 16 20 25 30 38 50 65 75 Allowable deviation ±1.0 ±1.5 ±2.0 ±3.0 The product of other specifications can also be prepared according to customers' requirement. b) Assortments In accordance with the content of inert Al2O3 from 25% to 95%, there are 17 assortments on every 5% as a grade. ITEM No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 AL203 content, (%) <25 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 >95