Silicon brick for carbon furnace

Silica brick is made of quartz stone material, the content of SiO₂ is above 93%, it has good resistance to acid slag and good heat conductivity. And the refractoriness is 1690~1710℃,RUL is beyond 1620℃.
 
SiO₂ has different types of crystals in different temperatures, and the transform between the crystals will cause the change of the bulk. So there is a close contact between the changes of SiO₂ crystals and the produce, performance and usage of silica bricks. During the heating, there will be changes of the bulk, and cristobalite changes most, then quartz, phosphorus quartz is the slowest of all and it also has good heat-conductivity. Carbon furnace should use the silica brick with small true density. And the phosphorus quartz is better than others.

 

Silica brick for carbon furnace	JG-95
	Wall	Other
SiO2 ≥	95
Al2O3 ≤	1.5
Fe2O3 ≤	1.5
CaO ≤	2.0
Apparent porosity (%) ≤	22	24
Cold crushing strength (MPa) ≥	35	35
0.2MPa refractoriness under load T 0.6 (℃) ≥	1670	1650
True density (g/cm3)	2.32	2.34
Residual Quartz (%) ≤	1.0	1.0
Permanent Linear Change On Reheating (1450℃X2h) (%)	0~0.2	0~0.2
Thermal Expansion 1000℃ (%) ≤	1.28	1.30