1. Round solid ball shape, saving binder addition;

2. High refractoriness and service temperature;

3. Good air permeability and excellent dispersibility;

4. Lower thermal expansion rate and thermal conductivity;

5. Lower bulk density, lower true specific gravity and lower specific surface area;

6. Standard particle sizes;

7. Easily reclaimed and lower breakage rate during dry crushing;

8. Single application, no need mix with other foundry sands;

9. To reduce pollution and protect environment.