Green Green, it’s green they say on the far side of the hill by John Davies at UJ MCTS Colloquium, SAIF

1. Green Green, It’s Green They Say,
on the Far Side of the Hill………
Folk Song
UNIVERSITY OF JOHANNESBURG
COLLOCUIUM 2011

2. THE SOUTH AFRICAN FOUNDRY INDUSTRY
1. NUMBER OF FOUNDRIES
METAL TYPE 2003 2007 2011 %Change
2011/2007
Ferrous 110 110 101* 8
Non Ferrous 103 101 80 21
TOTAL 213 211 181 14
* Includes 4 Investment Casting Foundries
In addition there are 13 Art Foundries and 9 Spin Casters
cf Germany = 900
USA = 2000
China = 2600

3. 2. ESTIMATE ANNUAL OUTPUT BY METAL TYPE
Estimated Estimated Estimated Growth
Annual Annual Annual 2011 vs.
Metal Type
Production Production Production 2007
2003 (tons) 2007 (tons) 2011 (tons) (%)
2003 2007 2011
Non-Ferrous 84,000 97,800 91,400 -7%
Ferrous 422,000 562,600 479,950 -15%
Total Annual Production 506,000 660,400 571,350 -13%
cf Germany 2.7m Tons
USA 11.0m Tons
China 39.0m Tons

4. 4. PROCESS TYPES
Process Type No. of Foundries using the Process (%)
Sand
Bonded sand 44%
Green sand 34%
Other 14%
Permanent Mould
Gravity 21%
Low Pressure 5%
High Pressure Die Casting 7%
Other 3%

5. 3. GEOGRAPHICAL LOCATION
3.1
No. of No. of No. of Percent of
Province Foundries Foundries Foundries Total
2003 2007 2011 2011
Gauteng 110 108 97 54%
Western Cape 26 16 15 8%
Kwa-Zulu Natal 20 26 24 13%
Eastern Cape 16 10 10 6%
Free State 10 7 6 3%
North-West 10 9 5 3%
Northern Cape 6 3 3 2%
Other 15 15 18 10%
NOTE: Other includes Mpumalanga and Vereeniging area

6. 5. FOUNDRY TYPE
No. of Foundries
Foundry Type No. of Foundries
(%)
Production 23 24%
Jobbing 50 52%
Production & Jobbing 24 24%

7. 6. AUTOMOTIVE CASTINGS (Est. Production)
6.1 METAL TYPE TONS % OF TOTAL / TYPE
Grey Iron 153 072 75
Ductile Iron 78 432 63
Aluminium 66 012 88
Zinc 408 15
Magnesium 240 95
TOTAL 298 164 52
6.2 METAL TYPE TONS % OF TOTAL
Ferrous 231 504 48
Non Ferrous 66 660 70

8. 7. EMPLOYMENT (Automotive Foundries)
7.1
METAL TYPE NO EMPLOYEES % OF TOTAL
Ferrous 2116 22
Non Ferrous 598 34
Total 2714 24
7.2 Automotive Foundries produce 52 percent of the output with 24 percent of the
total staff employed in the industry.

9. 8. FOUNDRY PRODUCING AUTOMOTIVE CASTINGS
METAL TYPE NO OF FOUNDRIES % OF TOTAL
Ferrous 8 (Est.) 8
Non Ferrous 16 20
Total 24 13
• 8 Automotive Iron Foundries generate 48 percent of the total Ferrous tonnage produced
• 16 Non Ferrous Foundries produce 70 percent of the total.

10. GREEN TECHNOLOGY
• DEFINITION: Technology that when properly implemented, allows an
organisation to meet it’s present needs without compromising
it’s future needs.
• Green Technology pervades every aspect of our lives
• Energy reduction is leading the way towards a greener future
• 90 Percent of manufactured goods / products contain cast components

11. Mold Making Heat Treatment
12% 6%
Other
12%
Core Making
8%
Melting
55%
Post Casting
7%

12. ENERGY SAVING OPPUTUNITIES
1. SCRAP SELECTION AND PREPARATION
2. CHARGING
3. MELTING
4. ALLOYING / REFINING / TREATMENT / SAMPLING
5. HOLDING
6. TAPPING / LADLES
7. TRANSPORTING
8. POURING
9. MAINTENANCE

13. 1. SCRAP SELECTION AND PREPERATION
• Safety
• Correct Size
• Density
• Cleanliness:
 Sheared versus Shredded Scrap
 Rusted Scrap
 Briquetted Swarf
• Preheating of Scrap?
• Induction Melting Limits the Range of Scrap Used

15. 2. CHARGING OF SCRAP
• Prepare the Charge Sequence
• Vibrating Systems
• Continuous During the Melt
• Pre Heat Charge in the Furnace
• Focus on Reducing the Duration of Charging to Maximise the Melting

16. 3. MELTING THE CHARGE
• Mains versus Medium Frequency / cupola
• Theoretical Power Versus “Best Practice”
• Benefits of Batch Melting
• Efficiency (No Holding) 97 Percent
• Max Power
• Power Density
• Melting Rate
• Furnace Size
• Production Planning
• Less Emmision
• Improved Control
• Improved Homogeneity
• Furnace Lids / Covers

17. Comparison of Practical Minimum, Theoretical Minimum and Best Practice Minimums for
Selected Processes
Best Tactic Best
Theoretical Industry % Practice % Practice
Selected Processes Minimum Average Difference Minimum Difference Minimum
Iron Induction Melting 351.5 796.3 56% 538.1 35% 1,689.50
Iron Cupola Melting 351.5 1,413.60 75% 1,002.50 65% 1,124.50
Aluminum Reverberatory 288.7 1,399.80 79% 510.5 43% 523.2
Melt Furnaces
Estimated Iron Induction Melting Energy Usage
Per Ton Melt
Gross Melt Tacit Tacit Tacit
10 Btu /
Item KWh/Ton Loss KWh/Ton KWh/Ton 10 Btu / Ton 10 Btu / Ton Ton**
Heel Melting Calculated 800 1.5% 812 2550 2.77 8.71 14.52
Heel Melting and Holding Estimated 954 1.5% 969 3041 3.31 10.39 17.31
Modern Batch Melter Caclulated 500 1.5% 508 1594 1.73 5.44 9.07
Batch Melter and Holding Estimated 530 1.5% 538% 1690 1.84 5.77 9.62
Includes Hold Power for 8 Hours per day and preheat gas at 74 kWh/ton melt for heel melter
Ship tons consider 60% yuekd

18. Induction and Cupola Melting Energy Comparison 10' Btu / Ton
Melt Tacit Melt Tacit Ship
Item Energy Energy Energy
Induction Heel Melting 3.31 10.39 17.31
Modern Induction Batch Melting 1.84 5.77 9.62
Low Efficiency Cupola 4.92 5.76 9.6
High Efficiency Cupola 3.25 3.84 6%

20. Historical Induction Melting Furnace Energy* (Delivered)
900
800
700
600
500
400
kWh/ton
300
200
100
0
1950 - 1960's 1960 - 1970's 1970 - 1980's 1990's

21. Modern Induction Melting Process
3.89 0.08 0.02 0.26 0.29
Losses
1.81 1.73 1.71 1.45 1.16
Electricit
y Power Refractory
Cable Iron
5.7 10’ Supply Coil Losses and Cover
Losses Melting
Btu Losses Losses
(Power Plant)

22. 4. ALLOYING / REFINING / DE - SLAGGING / SAMPLING
• Ferro – Alloy Additions
• Sampling – Floor Controls
• Sampling – Spectrometer Analysis
• Slag Removal – Tools, Efficiency
• Slag Wall, Slag Build – Up – Use of Fluxes
• Treatment of Metal

23. 5. HOLDING
• Avoid Holding Metal in Batch Furnaces
• Melt Cold – Pour Hot

24. 6. TAPPING / LADLES
• Melt Cold – Pour Hot
• Refractories
• Pre Heating Using Oxy – Fuel to Improve Efficiency
• Management

25. 7. TRANSFER OF MOLTEN IRON
• Preparation
• Speed and Accuracy of the Operation
• Temperature Control
• Skimming

26. 8. POURING
• High Power Thermal Plasma Heating
 Efficient Heating
 Fast
 Offers Metallurgical Benefits
• Existing Systems = Cold Ladles & Auto Pouring Units
Both have Disadvantages
• HPTP Offers a Cost Effective Solution
• Improved Temperature Control to +- 5 C
• Energy Efficiency Improvement of 20%

27. 9. MAINTENANCE
• Refractories:
 Replacement Schedule – Push Out
 Type of Refractory
 Campaign Life
 On Going Repairs – Chemical Erosion Leading to Failure
 Measurement
• Furnace:
 Regular Coil Inspection
 Water System Quality
 Harmonious Controls
 Short Main Power Cable Supply

28. CONCLUSION
• There is no “One Size Fits All” Solution
• There are no Immediate Technological Innovation in the melting of Iron
(No Magic Wand)
• Retrofitting Technology is Available
• The Approach Recommended is Continuous Improvement in Small Increments
• Opportunities for Energy Saving EXITS

29. ACKNOWLEDGEMENTS
• Advanced Melting Technologies “BCS Inc Nov 2005”
• Theoretical / Best Practice Energy Use in Metal Casting Operations “JF Suhfo, JT Radia – May 2004”
• Improvement in Energy Efficiency of a Melting furnace “Dr DS Padan, Tata Motors Limited”
• High Power thermal Plasma Heating in Automotive Casting Units: Tomorrow’s Technology Applied to
Today’s Casting “Luis Cobos Enal 2010”
• Casting Directory 2011 “Crawford Publications”
• How to Become a Practical Green Foundry Indsustry? “G Gigante, Thyssen Krupp – Wupaca, WI USA 2010