Description; A spinel forming alumina induction furnace lining. The aggregate is fused chrome alumina and the fines are high purity sintered and reactive aluminas and 12% dead burned seawater magnesia. There is no frit addition. Sintering is by spinel forming reaction which gives expansion and a tight sealed hot face, with powder behind it to prevent crack propagation.

Maximum service temperature; 1750ºC.

Density; Hand rammed density is around 2,9g/cm³.

Chemical analysis;


                   Total           Aggregate     Alumina fines
Al₂O₃             80%             87%             99,7%
Fe₂O₃           1,2%            2,0%             0,02%
Cr O                6%             10%        
SiO₂              0,2%             0,2%            0,04%
CaO              1,4%              2%              0,04%
MgO            12,0%                
Na₂O           0,06%                                  0,3%        
K₂O              0,6%            1%        
P₂O₅               0%        

Sintering:      12 hours on low power, then 2 hours at 1680 - 1700ºC  

Packaging:    25kg plastic bags

Shelf life:      6 months

Development no. 21943

Claimer: The above information had better be correct, since Dave Onderstall rests his reputation on it.