(1) Definition of Fused Ceramic Sand
Fused ceramic sand is an approximately spherical artificial casting sand formed by melting bauxite clay minerals with high alumina content. Its mineral composition is mullite phase and a small amount of corundum phase. Fused ceramic sand is also called ceramic foundry sand.
(2) Characteristics of Fused Ceramic Sand
Fused ceramic sand has higher refractoriness and approximate spherical shape than ordinary silica sand, so it has been applied in many fields.
For example, the surface quality of castings can be improved by manufacturing sand mold to produce steel castings and complex sand cores. It can be used as refractory aggregate for filling sand and casting coating in lost foam casting process. It can also be used as sand for 3D printing of sand mold (sand core). Fused ceramic sand in sand casting can also increase the proportion of used sand recycling, reduce waste sand emissions and environmental pollution, and reduce casting costs.
(3) Technical Index of Fused Ceramic Sand
The main physical and chemical properties of molten ceramic sand are shown in the table below.
Chemical Composition(%) | Angle coefficient | Bulk density /g·cm3 | Mohs hardness
| Refractoriness /℃ | Coefficient of thermal expansion （20-600℃）/（10-6/K） | PH value |
Al2O3: 70% min Fe2O3: 3% max | 1.06 | 2 | 7.5 | ≥ 1800 | 7.2 | 7.0-8.0 |
(4) Test Method for Fused Ceramic Sand
① The detection of iron oxide and aluminum oxide shall be carried out according to GB/T 7143-2010 methods for chemical analysis of silica sand
② The angle coefficient shall be tested according to GB/T 9442-2010 silica sand for casting.
③ The pH value shall be tested according to GB/T 9724-2007 general rules for the determination of pH value of chemical reagents.
④ The bulk density shall be tested according to GB/T 14684-2011 sand for construction.
⑤ The refractoriness shall be tested according to GB/T 7322-2017 test method for fire resistance of refractories.