Composite index

Open porosity w, %

Hardness limit at compaction, MPa

Density, ρ, g/sm³

Chemical resistance, %

Water

Sulfuric acid, ρ = 1.84

SN-1

16.2

230

2.28

99.41

99.15

SN-2

15.0

245

2.8

99,41

99.16

SN-3

16.0

240

3.2

99.36

99.15

SN-6

15.0

256

2.25

99.82

99.20

SN-7

15.2

258

2.31

99.79

99.25

SN-8

15.4

254

2.78

99.80

99.30