Chemistry_UG

1. REFRACTORIES
Dr. K. V. Nagalakshmi
&
Dr. B. Santosh Kumar

3. REFRACTORY MODELS

6. INTRODUCTION
Refractory comes from a French word “refractaire” meaning
high melting

8. Classification of refractories
 Refractories are classified into the following ways.
 1. Based on fusion temperature
 2. Based on chemical nature
 3. Based on nature of metal oxide

9. Based on fusion temperature
Al2O3-SiO2
FeCr2O4

11. Based on nature of metal oxide

18. POROSITY

19. POROSITY

20. THERMAL SPALLING
 Thermal spalling can be reduced by
 Using low porosity,
 Low coefficient of expansion
 Good thermal conductivity refractory bricks.
 Avoiding sudden temperature changes,
 Avoiding over firing the refractories at high temperature for a long time
 Modifying furnace design therby decreasing internal stress and strains

24. REFERENCES
 file:///C:/Users/HP/Downloads/refractories-140428154946-
phpapp02%20(1).pdf
 file:///C:/Users/HP/Downloads/refractories-151013153716-
lva1-app6891%20(2).pdf
 file:///C:/Users/HP/Downloads/refractories-dr-
180312111526%20(1).pdf