ZrO₂ (%)

Al₂O₃

(%)

Apparent porosity (%) 

Bulk density (g/cm³) 

C.C.S

(MPa)

Refractoriness (C) 

Inner

Outer

Inner

Outer

Inner

Outer

Inner

Outer

Inner

Outer

≥65

≥65

≤20

≤20

≥3.8

≤2.2

≥80

≥50

≥1800

≥1750

≥70

≥65

≤20

≤20

≥4.0

≤2.2

≥90

≥50

≥1800

≥1750

≥75

≥65

≤18

≤20

≥4.2

≤2.2

≥100

≥50

≥1850

≥1750

≥80

≥65

≤16

≤20

≥4.3

≤2.2

≥110

≥50

≥1850

≥1750

≥85

≥65

≤13

≤20

≥4.6

≤2.2

≥120

≥50

≥1900

≥1750

≥90

≥65

≤8

≤20

≥4.6

≤2.2

≥130

≥50

≥1900

≥1750

≥95

≥65

≤6

≤

≥4.6

≤2.2

≥140

≥50

≥1950

≥1750

NAME

Al₂O_{3 ,}(%)

F.C. (%)

Apparent Porosity (%)

Bulk density (g/cm³)

C.C.S.

(MPa)

Upper nozzle

≥85

≥3.0

≤10

≥3.0

≥88

Lower nozzle

≥75

≥3.5

≤8

≥2.8

≥88

NAME

Al₂O_{3 ,}(%)

F.C. (%)

Apparent Porosity (%)

Bulk density (g/cm³)

C.C.S.

(MPa)

Corundum

≥85

≥2.8

≤18

≥2.8

≥50

High alumina

≥60

≥2.5

≤16

≥2.5

≥60