Table of contents

1. Executive Summary 5. Compressed Air Technology
2.Technical Specifications 6. Recycling 
3.Abrasive Blasting Data 7. Blasting Nozzle Types
4. Rust Grades 8. Surface Area Calculation Tables

1. Executive Summary

1.1  Product Approval Specifications:

The mineral slag abrasive blasting grit mentioned hereunder has been tested and approved according to the following national and international standards:
SIS    (SECMET)  Swedish Standard
NACE  (SECMET) National Association of Corrosion Engineers
ASTM (SECMET) American Society for Testing Materials
SSPC (SECMET) Steel Structures Painting Council
SSPPC (CSIR)  Saldanha Steel, Specification for Painting & Corrosion Protection
AAC  (CSIR) Anglo American Corporation Specification for Corrosion Protection of Steelwork with Coatings

1.2  Product Description:        

Afrigrit’s superior, slag blasting, abrasive grit: AGT 1, 2 & 3  has been the result of extensive research, intensive investigation and numerous evaluations and analyses conducted by accredited research laboratories.
The grit is a grey/brown angular shaped solid, particulate, which is inert, odorless and is incapable of supporting combustion.
The grit has been graded into the following three sizes (Superfine) AGT 1, (Fine) AGT 2 and (Medium) AGT 3, which suit most abrasive blasting operations.

1.3  Product Scope:

AGT 1,2 & 3 has proved to be a superior product for the following applications:
The removal of:   
Mill scale, rust, old paint, tar, epoxy
The cleaning of:
Metal, wood, tin, road surfaces
Etching into:
glass, plastics, metals, ceramics, granite

1.4  Product Benefits:

The main advantages of AGT 1,2 & 3 are the following:  

* Complies with Health & Safety requirements
*  Environment friendly  (air and ground contamination)
*  Superior finish 
*  Excellent break down rate
*  Tremendous cutting rate due to sharp angular configuration
*  Create superb coating and bonding surface
*  Its performance rate per m2 exceeds expectations
*  The higher than normal density of 3470 kg/m3 and hardness of more than 6 on the Moh’s scale enhances its abrasive qualities immensely.
* Competitive low price
* Irregular surface profile of blasted material offers a high degree of grip for permanent coating bond.
* Product relatively dust free < 13% liberation
* Weber Reilly Test result: less than 100mg\m²

1.5 Approvals:

* SecMet Metallurgical & Corrosion Consultants (Sasol)
* Mpumalanga Department of Labour
* Jotun Paints SA
* Sigma Coatings
* Mozal
* Conforms to SABS 064-1979 FIRST REVISION
* Anglo Gold
* bhp Billiton
* Iscor

1.6  Accredited Testing Authorities used:

* SecMet Metallurgical & Corrosion Consultants
* Gencor Laboratories
* Columbus Stainless Steel (Group Occupational Hygiene Department) Approve Inspection Authority for the Monitoring of Physical & Chemical Stress factors.
* CSIR
* MINTEK Group Chemistry

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2.Technical Specifications

2.1  Profile & Size (SECMET tested):

AGT 1   AGT 2   AGT 3  
Grading   2   3   5  
Size   0.3-1mm   1.1-1.64mm   1.65-2.47mm  
Profile (Average)   52 mm   87mm   115mm  

2.2  Specific Gravity (SECMET tested):

Actual Specification No1 ASTM C 128-88
3470 kg/m3 Minimum: 2500 kg/m3

2.3 Hardness (SECMET tested):

Actual Specification for mineral slag abrasives 
³ 6 Minimum: 6

2.4  Weight Loss on Ignition (SECMET tested):

Actual Specification for mineral slag abrasives 
0.68 %  Minimum: -1.0 % Maximum: 5.0 %

2.5  Water-soluble contaminants (SECMET tested):

Parameter Actual

Specification for mineral slag abrasives

pH 9.7 Not to be below 6.2
Conductivity mS/cm 70.8 < 100
Sulphate mg/l 15  
Nitrate mg/l 2.1  
Chloride mg/l 1.73 (0.00173%)  < 0.03 % by mass

2.6 Oil content (CSIR) & (SECMET) tested:

Specifications: abrasive shall show no presence of oil.

AGT 1 AGT 2 AGT 3
Nil Nil Nil

2.7  Moisture content (CSIR) & (SECMET) tested:

Actual Specification ASTM C-566 
0.22 % Maximum: 0.5 % by weight

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3. Abrasive Blasting Data

3.1  Blast Cleaning – Preparation Grades (International Standard):

Grade – BS 7079  SS 05 59 00 Description When viewed with the naked eye:
SA 2 

Grade 3

Thorough blast cleaning:

Commercial finish

65% clean

The surface shall be free from visible oil, dirt & grease, & from poorly adhering mill scale, rust, paint coatings & foreign matter. Any residual contamination should be firmly adhering.
SA 2 ½

Grade 2

Very thorough blast cleaning:

Near white metal

85% clean

 

The surface shall be free from visible oil, dirt & grease, & from poorly adhering mill scale, rust, paint coatings & foreign matter. The metal has a grayish colour.

Any traces of contamination shall be visible only as slight stains in the form of spots and or stripes.

SA 3

Grade 1

Blast cleaning to pure metal:

White metal

100 % clean

 

The surface shall be free from visible oil, dirt & grease, & from poorly adhering mill scale, rust, paint coatings & foreign matter.

The blasted surface must have a uniform metallic colour.

3.2  Blasting Grades:

Following is a table giving a clear indication of the comparative blasting grades applicable to national and international standards:
Blasting Grade Common Standards Comparison

SSPC

Steel Structures Painting Council

BS 7079

British Standards

SS 05 59 00

Swedish Standards

BS 4232

NACE

National Association of Corrosion Engineers

White metal (SP5) Sa 3 1st Quality Grade 1
Near white metal (SP10) Sa 2.5 2nd Quality Grade 2
Commercial finish (SP6)  Sa 2 3rd Quality Grade 3

3.3  Packaging

* Loose
* 30kg bags
* Bulk bags
* 30Kg bags packed in bulk bags

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4. Rust Grades

A Surface mostly covered with adherent mill scale, with little or no rust
B Mill scale has begun to flake, rust has started to form
C Mill scale has rusted away or can be scraped off easily and slight pitting has taken place
D Mill scale has rusted away and general pitting can be seen with naked eye.

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5. Compressed Air Technology

“Energy is Money” can definitely be applied to compressed air as being one of the most expensive forms of energy. Regardless of the source providing power to the compressor it will mean that cost is involved. Therefore it makes good sense to manage your energy (compressed air) wisely. Research has proved that a 3mm hole in an air hose will easily add up to R40 000-00 a year lost in cost. Consider the following:
* Correct specified perforation free hoses and efficient seals;
* Friction loss due to lengthy hoses;
* The correct Venturi nozzle in relation to the compressor capacity;
* Maintaining a constant nozzle pressure of 700Kpa (considered the ideal pressure);
* A qualified blasting operator; 
* An efficient blasting medium;
* Regular maintenance or servicing of equipment e.g. valves; seals, hoses etc.

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6. Recycling 

Is recycling a cost efficient activity? Consider the following:
* Time, effort and labour spent on the reclamation of spent grit;
* Possible contamination of blasted substrate due to impurities in the spent abrasive;
* Loss in production;
* Breakdown in particle size resulting in an insufficient blast profile;
* Excessive dust emission;
* Possibility of blockages to pot and nozzle;
* Conductivity levels;
* The possible delaminating of protective coating system.

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7. Blasting Nozzle Types

Type Velocity of abrasive leaving nozzle @ 7 Bar Blast pattern concentration
Straight bore 350km/hr Concentrates most of abrasive at center of blast pattern
Venturi nozzle 720 km/hr Uniform concentration of abrasive in bl ast pattern

Nozzle blasting pressures:

Increased nozzle pressure:
* The optimal pressure measured at the blasting nozzle is 700kPa or 7 bar. 
* An increase of pressure above 7 bar does not increase the velocity of the abrasive to any economical levels.
* For safety reasons it is not good to increase pressure above 7 bar.

Decreased nozzle pressure:
* 7 Bar is the ideal nozzle pressure, as a rule of thumb 1 % loss in pressure is equal to 1.5% loss in efficiency.
Nozzle pressure % Pressure loss %  Efficiency

%  Efficiency Lost

7.0 bar(100psi) 0 % 100 % 0 %
6.5 bar(+-95psi) 7 % 89 % 11 %
6.0 bar(+-85psi) 14 % 79 % 21 %
5.5 bar(80psi) 21 % 68 % 32 %
5.0 bar(+-73psi) 29 % 56 % 46 %

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8. Surface Area Calculation Table:

Pipe Diameter

Pipe Diameter Ø mm

Surface area per running meter m2

Pipe Diameter Ø mm

Surface area per running meter m2

25

0.08

925

2.91

57

0.16

950

2.99

75

0.24

975

3.06

100

0.31

1000

3.14

125

0.39

1025

3.22

150

0.47

1050

3.30

175

0.55

1075

3.38

200

0.63

1100

3.46

225

0.71

1125

3.54

250

0.79

1150

3.61

275

0.86

1175

3.69

300

0.94

1200

3.77

325

1.02

1225

3.85

350

1.10

1250

3.93

375

1.18

1275

4.01

400

1.26

1300

4.09

425

1.34

1325

4.16

450

1.41

1350

4.24

475

1.49

1375

4.32

500

1.57

1400

4.4

525

1.65

1425

4.48

550

1.73

1450

4.56

575

1.81

1475

4.64

600

1.89

1500

4.71

625

1.96

1525

4.79

650

2.04

1550

4.87

675

2.12

1575

4.95

700

2.20

1600

5.03

725

2.28

1625

5.11

750

2.36

1650

5.19

775

2.44

1675

5.26

800

2.51

1700

5.34

825

2.59

1725

5.42

850

2.67

1750

5.50

875

2.75

1775

5.58

900

2.83

1800

5.66

 

Surface Area of Pipes

Pipe Diameter Ø mm

Surface area per running meter m2

Pipe Diameter Ø mm

Surface area per running meter m2

25

0.08

925

2.91

57

0.16

950

2.99

75

0.24

975

3.06

100

0.31

1000

3.14

125

0.39

1025

3.22

150

0.47

1050

3.30

175

0.55

1075

3.38

200

0.63

1100

3.46

225

0.71

1125

3.54

250

0.79

1150

3.61

275

0.86

1175

3.69

300

0.94

1200

3.77

325

1.02

1225

3.85

350

1.10

1250

3.93

375

1.18

1275

4.01

400

1.26

1300

4.09

425

1.34

1325

4.16

450

1.41

1350

4.24

475

1.49

1375

4.32

500

1.57

1400

4.4

525

1.65

1425

4.48

550

1.73

1450

4.56

575

1.81

1475

4.64

600

1.89

1500

4.71

625

1.96

1525

4.79

650

2.04

1550

4.87

675

2.12

1575

4.95

700

2.20

1600

5.03

725

2.28

1625

5.11

750

2.36

1650

5.19

775

2.44

1675

5.26

800

2.51

1700

5.34

825

2.59

1725

5.42

850

2.67

1750

5.50

875

2.75

1775

5.58

900

2.83

1800

5.66

 

Surface area and mass of channel iron sections

Channel Iron

Surface Area

Standard size

Mm

Mass per meter

Kg/m

Per metre

M2

Per ton

M2

80 x 40

8.64

0.314

36.22

100 x 50

10.6

0.372

35.22

120 x 55

13.4

0.429

32.17

140 x 60

16.0

0.487

30.46

160 x 65

18.8

0.545

28.90

180 x 70

22.0

0.603

27.45

200 x 75

25.3

0.660

26.13

220 x 80

29.4

0.718

24.41

240 x 85

33.2

0.775

23.35

260 x 90

37.9

0.833

21.97

280 x 95

41.8

0.891

21.24

300 x 100

46.2

0.949

20.57

380 x 102

63.1

1.110

17.66

400 x 110

71.8

1.180

16.45

76 x 38

6.7

0.281

42.00

127 x 64

14.9

0.479

32.09

152 x 76

17.9

0.573

32.10

178 x 54

14.5

0.544

37.42

381 x 102

55.1

1.120

20.32

 

Surface area of steel sections:

SURFACE AREA OF UNIVERSAL “I” BEAMS (PARALLEL FLANGE)

Size

Mass per meter

Surface area

Size

Mass per metre

Surface area

Per metre

Per ton

Per metre

Per ton

mm

Kg/m2

M2

M2

Mm

Kg/m2

M2

M2

200*133

25.3

0.915

36.23

457*191

67.1

1.632

24.31

 

29.8

0.923

30.94

 

74.7

1.640

21.98

254*146

31.3

1.062

33.90

 

82.0

1.648

20.09

 

37.2

1.072

28.80

 

89.7

1.656

18.47

 

43.2

1.081

25.03

 

98.3

1.666

16.94

305*102

24.5

0.991

40.47

533*210

82.2

1.850

22.52

 

28.6

1.000

35.01

 

92.5

1.861

20.11

 

32.8

1.009

30.72

 

101

1.870

18.44

305*165

40.5

1.240

30.60

 

109

1.877

17.22

 

46.1

1.248

27.05

 

122

1.889

15.4

 

53.6

1.258

23.50

610*229

101

2.072

20.39

356*171

44.8

1.357

30.11

 

113

2.083

18.37

 

50.7

1.365

26.91

 

125

2.094

16.75

 

56.7

1.372

24.19

 

140

2.106

15.06

 

67.2

1.385

20.63

610*305

149

2.386

15.98

406*140

38.6

1.331

34.46

 

179

2.406

13.47

 

46.3

1.343

28.99

 

238

2.446

10.25

406*178

53.8

1.483

27.56

686*254

125

2.318

18.52

 

59.8

1.491

24.95

 

140

2.331

16.64

 

67.2

1.499

22.32

 

152

2.341

15.36

 

74.8

1.507

20.14

 

170

2.354

13.83

 

‘I’ steel section with taper flange

Nominal size

Mass per metre

Surface area

Per metre

Per ton

mm

Kg/m2

M2

M2

102*64

9.65

0.426

44.13

127*76

13.40

0.523

39.20

152*89

17.10

0.622

36.34

178*102

21.50

0.718

33.49

203*102

25.30

0.768

30.31

203*152

52.10

0.930

17.85

254*152

59.50

1.032

17.37

305*152

65.50

1.132

17.2

 

UNIVERSAL COLUMNS ‘h’ steel section with PAR flange

Nominal size

Mass per metre

Surface area

Per metre

Per ton

mm

Kg/m2

M2

M2

152*152

23.4

0.889

38.15

 

29.8

0.900

29.87

 

37.2

0.912

24.59

203*203

46.2

1.187

25.71

 

52.1

1.194

22.93

 

59.6

1.204

20.17

 

71.5

1.218

17.07

 

86.4

1.236

14.31

254*254

72.9

1.485

20.36

 

89.2

1.502

16.83

 

107

1.519

14.16

 

132

1.544

11.73

 

167

1.576

9.45

305*305

96.8

1.789

18.48

 

118

1.806

15.37

 

137

1.822

13.32

 

158

1.839

11.67

 

198

1.872

9.45

 

240

1.905

7.94

 

283

1.938

6.85

356*368

129

2.137

16.48

 

153

1.153

14.02

 

177

2.170

12.25

 

202

2.187

10.80

 

477

2.429

5.10

356*406

235

2.279

9.68

 

287

2.312

8.05

 

340

2.346

6.91

 

393

2.379

6.05

 

467

2.425

5.19

 

CHANNEL IRON steel sectionS

Nominal size

Mass per metre

Surface area

Per metre

Per ton

mm

Kg/m2

M2

M2

80*45

8.64

0.314

36.22

100*50

10.6

0.372

358.22

120*55

13.4

0.429

32.17

140*60

16.0

0.487

30.46

160*65

18.8

0.545

28.90

180*70

22.0

0.603

27.45

200*75

25.3

0.660

26.13

220*80

29.4

0.718

24.41

240*85

33.2

0.775

23.35

260*90

37.9

0.833

21.97

280*95

41.8

0.891

21.24

300*100

46.2

0.949

20.57

380*102

63.1

1.110

17.66

400*110

71.8

1.180

16.45

76*38

6.7

0.281

42.00

127*64

14.9

0.479

32.09

152*76

17.9

1.573

32.10

178*54

14.5

0.544

37.42

381*102

55.1

1.120

20.32

 

SURFACE AREA OF ANGLE IRONS (UNEQUAL LEG)

Size

Mass per meter

Surface area

Size

Mass per metre

Surface area

Per metre

Per ton

Per metre

Per ton

mm

Kg/m2

M2

M2

Mm

Kg/m2

M2

M2

65*50*3

5.16

0.225

43.54

100*75*12

15.4

0.341

22.11

65*50*8

6.75

0.225

33.31

125*75*8

12.2

0.391

32.11

75*50*6

5.65

0.244

43.21

125*75*10

15.0

0.391

26.00

75*50*8

7.39

0.244

33.02

125*75*12

17.8

0.391

21.92

80*60*6

6.37

0.273

42.91

150*75*10

17.0

0.441

25.94

80*60*8

8.34

0.273

32.73

150*75*12

20.2

0.441

21.84

90*65*6

7.07

0.303

42.86

150*75*15

24.8

0.441

17.74

90*60*8

9.29

0.303

32.64

150*90*10

18.2

0.407

25.84

90*60*10

11.4

0.303

26.50

150*90*12

21.6

0.407

21.75

100*65*8

9.94

0.321

32.32

150*90*15

26.6

0.407

17.64

100*75*6

8.04

0.341

42.44

 

 

 

 

100*75*8

10.6

0.341

32.29

 

 

 

 

100*75*10

13.0

0.341

26.18

 

 

 

 

 

SURFACE AREA OF ANGLE IRONS (EQUAL LEG)

Size

Mass per meter

Surface area

Per metre

Per ton

Mm

Kg/m2

M2

M2

25*25*3

1.11

0.097

86.19

25*25*5

1.77

0.097

54.25

30*30*3

1.36

0.116

74.86

30*30*5

2.18

0.116

53.08

40*40*3

1.84

0.155

83.99

40*40*5

2.97

0.155

52.06

40*40*6

3.52

0.155

44.04

45*45*3

2.09

0.174

83.24

45*45*5

3.38

0.174

51.51

45*45*6

4.00

0.174

43.52

50*50*5

3.77

0.194

51.45

50*50*6

4.47

0.194

43.41

50*50*8

5.82

0.194

33.33

60*60*5

4.57

0.233

51.04

60*60*6

5.42

0.233

42.98

60*60*8

7.09

0.233

32.89

60*60*10

8.69

0.233

26.83

70*70*6

6.38

0.272

42.67

70*70*8

8.36

0.272

32.57

70*70*10

10.3

0.272

26.50

80*80*6

7.34

0.311

42.44

80*80*8

9.63

0.311

32.33

80*80*10

11.9

0.311

26.25

80*80*12

14.0

0.311

22.20

90*90*8

10.9

0.350

32.15

90*90*10

13.4

0.350

26.07

100*100*8

12.2

0.390

31.99

100*100*10

15.0

0.390

25.91

100*100*12

17.8

0.390

21.85

100*100*15

21.9

0.390

17.79

120*120*10

18.2

0.469

25.76

120*120*12

21.6

0.469

21.68

120*120*15

26.6

0.469

17.60

150*150*12

27.3

0.469

21.43

150*150*15

33.8

0.586

17.35

150*150*18

40.1

0.586

14.63

200*200*16

48.5

0.586

16.17

200*200*18

54.2

0.785

14.46

200*200*20

59.9

0.785

13.09

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