As per IS:6

 As per IS:8

Safe Working Temperature

14000 C

14500 C

Bulk Density

2 gms/cc

2 gms/cc

Cold Crushing Strength

200 kg/cm2

250 kg/cm2

Apparent Porosity

30% max.

30% max.

P.C.E. (Orton Cone)

30

32

RUL

1300 ta0 C min.

1400 ta0 C min.

PLC at 13500 C for 5 hrs.

1%

1%

Size Tolerance

+/- 2%

+/- 2%

Alumina as Al2O3

30% min.

40% min.

Iron as Fe2O3

2.5 % max.

2.5 % max.

Silica as SiO2

65% max.

57% max.

Alkalis

Trace

Trace