Brown aluminium oxide (A)

Brown aluminium oxide (A) is produced by fusion of bauxite in an electric arc furnace at high temperatures. The brownish coloured product shows high hardness as well as extreme toughness. The materials are used to grind metals of high-tensile strength such as steel, annealed malleable iron and hard bronze. It can also be used as high-class refractory.

 

Grain Usages and Types 

Usage

For vitrified wheels

For organic wheels

For coated abrasives

For refractory materials

Type

A

A-B

A-P

A-R

 

 

Physical Characteristics

Item

Basic mineral

Crystal system

Crystal color

Mohs hardness

Density

Brown aluminium oxide

α- Al2O3

Hexagonal

Brown

9

≥3.90g/cm3

Item

Micro hardness

Electrical resistivity

Grinding ability(compared
with diamond as one)

Linear expansion coefficient
(when 900℃ α•10-6k-1)

Brown aluminium oxide

HV1800-2200

1014-1016Ω•cm

0.10

7.6

 

 

Chemical Composition ( GB/T 2478-2008 )

Type

Grit

Chemical Composition(%, by weight)

Al2O3

TiO2

CaO

SiO2

Fe2O3

A

F4-F80

95.00-97.50

1.70-3.40

≤0.42

≤1.00

≤0.30

F90-F150

94.50-97.00

F180-F220

94.00-97.00

1.70-3.60

≤0.45

≤1.00

≤0.30

F230-F800

≥93.50

1.70-3.80

≤0.45

≤1.20

≤0.30

F1000-F1200

≥93.00

≤4.00

≤0.50

≤1.40

≤0.30

A-B

F4-F80

≥94.00

1.50-3.80

≤0.45

≤1.20

≤0.30

F90-F220

≥93.00

1.50-4.00

≤0.50

≤1.40

≤0.30

F230-F800

≥92.5

≤4.20

≤0.60

≤1.60

≤0.30

F1000-F1200

≥92.00

≤4.20

≤0.60

≤1.80

≤0.30

A-P

P12-P80

95.00-97.50

1.70-3.40

≤0.42

≤1.00

≤0.30

P100-P150

94.50-97.00

P180-P220

94.00-97.00

1.70-3.60

≤0.45

≤1.00

≤0.30

P240-P800

≥93.50

1.70-3.80

≤0.45

≤1.20

≤0.30

P1000-P1200

≥93.00

≤4.00

≤0.50

≤1.40

≤0.30

P1500-P2500

≥92.50

≤4.20

≤0.55

≤1.60

≤0.30

A-R

0-1mm

94.00-97.50

1.50-3.80

≤0.45

≤1.40

≤0.30

1-3mm

94.00-97.50

1.50-3.80

≤0.45

≤1.40

≤0.30

3-5mm

94.00-97.50

1.50-3.80

≤0.45

≤1.40

≤0.30

5-8mm

94.00-97.50

1.50-3.80

≤0.45

≤1.40

≤0.30

 Note: Special requirement on chemical composition can be satisfied through discussion.

 

 

Guarnteed bulk density range of coarse grains(A / A-B, g/cm3

Grit

Grade

Roll Crushing

Ball Mill

BMK

F12

1.84±0.05

1.92±0.05

2.00±0.05

F14

1.83±0.05

1.91±0.05

1.99±0.05

F16

1.81±0.05

1.90±0.05

1.98±0.05

F20

1.78±0.05

1.87±0.05

1.98±0.05

F22

1.76±0.05

1.85±0.05

1.96±0.05

F24

1.74±0.05

1.84±0.05

1.94±0.05

F30

1.72±0.05

1.81±0.05

1.90±0.05

F36

1.70±0.05

1.79±0.05

1.87±0.05

F40

1.68±0.05

1.76±0.05

1.85±0.05

F46

1.65±0.05

1.75±0.05

1.83±0.05

F54

1.63±0.05

1.73±0.05

1.81±0.05

F60

1.62±0.05

1.72±0.05

1.79±0.05

F70

1.60±0.05

1.69±0.05

1.78±0.05

F80

1.57±0.05

1.65±0.05

1.76±0.05

F90

1.54±0.05

1.64±0.05

1.74±0.05

F100

1.51±0.05

1.60±0.05

1.70±0.05

F120

1.49±0.05

1.59±0.05

1.68±0.05

F150

1.47±0.05

1.57±0.05

1.65±0.05

F180

1.45±0.05

1.56±0.05

1.61±0.05

F220

1.43±0.05

1.53±0.05

1.59±0.05

 Note: Special requirement on bulk density can be satisfied through discussion.

 

 

Guarnteed bulk density range of coarse grains(A-P, g/cm3

Grit

Grade

Roll Crushing

Ball Mill

BMK

P12

1.80±0.05

1.88±0.05

1.96±0.05

P16

1.78±0.05

1.85±0.05

1.94±0.05

P20

1.76±0.05

1.83±0.05

1.93±0.05

P24

1.73±0.05

1.81±0.05

1.92±0.05

P30

1.70±0.05

1.79±0.05

1.90±0.05

P36

1.68±0.05

1.76±0.05

1.88±0.05

P40

1.65±0.05

1.73±0.05

1.86±0.05

P50

1.62±0.05

1.71±0.05

1.83±0.05

P60

1.59±0.05

1.67±0.05

1.81±0.05

P80

1.57±0.05

1.64±0.05

1.77±0.05

P100

1.55±0.05

1.62±0.05

1.73±0.05

P120

1.52±0.05

1.59±0.05

1.70±0.05

P150

1.49±0.05

1.55±0.05

1.66±0.05

P180

1.47±0.05

1.52±0.05

1.62±0.05

P220

1.45±0.05

1.50±0.05

1.58±0.05

 Note: Special requirement on bulk density can be satisfied through discussion.

 



Brown Aluminium Oxide(A)