Investigation into the Effects of Larger
Particles on Proctor/Fagerberg
Transportable Moisture Limit Test
Method
By:
Corin...
Definitions
IMSBC Code – International Maritime Solid Bulk Cargoes Code
2012 Edition
• Appendix 2 – Defines test procedure...
Definitions

Transportable Moisture Limit (TML):

The TML value is the moisture content of a bulk material above
which it ...
Definitions
Liquefaction:
Occurs when the volume of spaces between particles reduces,
causing pore water pressure to rise,...
How to Determine TML

• Flow Table Test

• Penetration Test
• Proctor/Fagerberg Test
• Procedures for each test method are...
Importance of TML
•

There is clear need to accurately determine a maximum
moisture content of a bulk material for safe tr...
Summary of Proctor/Fagerberg Test
Method
•
•
•
•
•
•

•

Cell Volume = 1000 cm3
Minimum of 5 test points (from dry to almo...
Void Ratio

Output of the Proctor/Fagerberg Test
Method

Gross Water Content [% by Mass]

Bulk Solids: Science / Engineeri...
Proctor/Fagerberg Method Questioned

•Particle Density – Heavy reliance on this figure but nowhere in
the code does it cle...
Proctor/Fagerberg Method Questioned

•Starting Moisture Content – Does drying out the material fully alter
the material pr...
J & J Study

Study was conducted to explore the effects of particle
size on TML values

Bulk Solids: Science / Engineering...
J & J Study Part 1
Jenike & Johanson (J&J) investigated the effects of including >5
mm particles in the Proctor/Fagerberg ...
J & J Study Part 1
Determine TML values for a single sample of Australian Iron Ore
which was divided into four subsamples;...
J & J Study Part 1
TML determination of each subsample

Bulk Solids: Science / Engineering / Design
J & J Study Part 1
• To examine the sensitivity of moisture content to PSD, Sample 3 was
adjusted to its average TML value...
J & J Study Part 1 Summary

• Coarser samples often yield lower TML values
• The finer fractions of the ore have higher mo...
J & J Study Part 2

6 Types of Iron Ore
12 mm x 0 mm

5 mm x 0 mm
TML
TML

Bulk Solids: Science / Engineering / Design
J & J Study Part 2

12 mm x 0 mm

Samples Adjusted to TML
MC %

Split

5 mm x 0 mm

12 mm x 5 mm

MC %

MC %

Bulk Solids:...
J & J Study Part 2 Results

Bulk Solids: Science / Engineering / Design
J & J Study Part 2 Results

In five of the six samples tested the moisture content of
the -5 mm fractions were higher than...
J & J Study Summary

•The moisture content varied as a function of the sample’s
particle size distribution.
•The fine frac...
J & J Study Summary

• Measured TML values may either increase or decrease
as materials become coarser,
• If the TML value...
J & J Study Summary

TML = 8.8%
TML = 8.6%
5mm x 0mm
12mmx 0mm

Bulk Solids: Science / Engineering / Design
J & J Study Conclusion
• Iron ores shipped in other locations around the globe at
>TML values measured.
• If the standard ...
Questions?

Corin Holmes, MSc Eng
Technical Officer
Jenike & Johanson Perth, WA
cholmes@jenike.com
Bulk Solids: Science / ...
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Corin Holmes, Jenike & Johanson: Investigating the Effects of Larger Particles on Proctor/Fagerberg Transportable Moisture Limit Test Method

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Corin Holmes, Technical Officer, Jenike & Johanson Pty Ltd delivered this presentation at the 2013 FE Tech Conference. The event focussed on the economics of processing and the beneficiation of iron ore. In light of the slowdown in demand for iron ore and pricing decreases, the need to process more efficiently and cost effectively is a challenge. The conference examined on how we can achieve greater value from the iron ore supply chain, with topics addressing optimisation and streamlining processes, applying improved technologies, understanding the ore body and how to properly characterise it, knowing the steel makers needs. For more information please visit the conference website: http://www.informa.com.au/fe-tech

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Corin Holmes, Jenike & Johanson: Investigating the Effects of Larger Particles on Proctor/Fagerberg Transportable Moisture Limit Test Method

  1. 1. Investigation into the Effects of Larger Particles on Proctor/Fagerberg Transportable Moisture Limit Test Method By: Corin Holmes, MSc Eng. Technical Officer Jenike & Johanson Bulk Solids: Science / Engineering / Design
  2. 2. Definitions IMSBC Code – International Maritime Solid Bulk Cargoes Code 2012 Edition • Appendix 2 – Defines test procedures to determine TML Bulk Solids: Science / Engineering / Design
  3. 3. Definitions Transportable Moisture Limit (TML): The TML value is the moisture content of a bulk material above which it is considered unsafe to transport in a bulk carrier as it may liquefy Bulk Solids: Science / Engineering / Design
  4. 4. Definitions Liquefaction: Occurs when the volume of spaces between particles reduces, causing pore water pressure to rise, reducing the shear strength of the particles.[2] Material in a liquid-like flow state [2] Bulk Cargo Liquefaction (Iron Ore Fines and Nickel Ore), Standard Cargo, February 2011, pp. 2 Bulk Solids: Science / Engineering / Design
  5. 5. How to Determine TML • Flow Table Test • Penetration Test • Proctor/Fagerberg Test • Procedures for each test method are given in Appendix 2 of the IMSBC Code • We will focus on Proctor/Fagerberg test method Bulk Solids: Science / Engineering / Design
  6. 6. Importance of TML • There is clear need to accurately determine a maximum moisture content of a bulk material for safe transport in bulk cargoes. • In 2009 two ships, the Asian Forest and the Black Rose capsized and sank following liquefaction of iron ore cargoes after being loaded in Indian ports during the monsoon season.[3] • In 2010 there was a further loss of three bulk carriers carrying nickel ore loaded in Indonesia.[4] [3] Bilbrough, A., et al., Circular: India – Safe Shipment of Iron Ore Fines from Indian Ports, The London P&I Club, Dec 13, 2010 pp. 1 [4] Bulk Cargo Liquefaction (Iron Ore Fines and Nickel Ore), Standard Cargo, February 2011, pp. 2 Bulk Solids: Science / Engineering / Design
  7. 7. Summary of Proctor/Fagerberg Test Method • • • • • • • Cell Volume = 1000 cm3 Minimum of 5 test points (from dry to almost saturated) Material is dried prior to test Material filled into cell in 5 equal amounts Tamper mass, drop height, number of tamps Intersection of void ratio curve and 70% of saturation = TML value Maximum particle size of 5 mm Bulk Solids: Science / Engineering / Design
  8. 8. Void Ratio Output of the Proctor/Fagerberg Test Method Gross Water Content [% by Mass] Bulk Solids: Science / Engineering / Design
  9. 9. Proctor/Fagerberg Method Questioned •Particle Density – Heavy reliance on this figure but nowhere in the code does it clearly define how this value is measured •Consolidation Pressure – Does tamping the material surface 25 times over five layers equate to a compacted density like that which would be seen by a material in a bulk vessel? •Segregation & Whipping – Does liquefaction by whipping really occur in a ships hold? Does segregation? Do they play a role in potential liquefaction? Bulk Solids: Science / Engineering / Design
  10. 10. Proctor/Fagerberg Method Questioned •Starting Moisture Content – Does drying out the material fully alter the material properties? •Conservatism – Why is the TML value determined to be at the intersection of void ratio curve and 70% of saturation as the test method outlines? Perhaps 80 - 85% is still conservative enough? •What about particle size? Why was 5mm chosen? Bulk Solids: Science / Engineering / Design
  11. 11. J & J Study Study was conducted to explore the effects of particle size on TML values Bulk Solids: Science / Engineering / Design
  12. 12. J & J Study Part 1 Jenike & Johanson (J&J) investigated the effects of including >5 mm particles in the Proctor/Fagerberg test procedure, and the resultant determination of TML values. •The inter-particle void space in a material compacted per the Proctor/Fagerberg TML test procedure will vary depending on the sample’s particle size distribution (PSD). •The finer fraction of a bulk material tends to carry a higher proportion of the moisture than the coarser fraction. •Determining the TML value on coarser particle distributions may result in a different TML value than that determined for the minus 5mm fraction alone. Bulk Solids: Science / Engineering / Design
  13. 13. J & J Study Part 1 Determine TML values for a single sample of Australian Iron Ore which was divided into four subsamples; separated by their respective size distributions. Bulk Solids: Science / Engineering / Design
  14. 14. J & J Study Part 1 TML determination of each subsample Bulk Solids: Science / Engineering / Design
  15. 15. J & J Study Part 1 • To examine the sensitivity of moisture content to PSD, Sample 3 was adjusted to its average TML value of 9.6% moisture • It was then quartered and sieved to produce three subsamples with maximum particle size to match those of Samples 1, 2, and 3 • The moisture contents (wet basis) for each of these subsamples were determined Bulk Solids: Science / Engineering / Design
  16. 16. J & J Study Part 1 Summary • Coarser samples often yield lower TML values • The finer fractions of the ore have higher moisture contents than the coarser or full size distributions Bulk Solids: Science / Engineering / Design
  17. 17. J & J Study Part 2 6 Types of Iron Ore 12 mm x 0 mm 5 mm x 0 mm TML TML Bulk Solids: Science / Engineering / Design
  18. 18. J & J Study Part 2 12 mm x 0 mm Samples Adjusted to TML MC % Split 5 mm x 0 mm 12 mm x 5 mm MC % MC % Bulk Solids: Science / Engineering / Design
  19. 19. J & J Study Part 2 Results Bulk Solids: Science / Engineering / Design
  20. 20. J & J Study Part 2 Results In five of the six samples tested the moisture content of the -5 mm fractions were higher than the TML values determined for the -5 mm subsamples. The -5 mm fraction is ~78% of the sample. Bulk Solids: Science / Engineering / Design
  21. 21. J & J Study Summary •The moisture content varied as a function of the sample’s particle size distribution. •The fine fraction of an ore will tend to have a higher moisture content than the full size distribution, since the finer fractions of a bulk material tend to carry a higher proportion of moisture than the coarser fractions do. Bulk Solids: Science / Engineering / Design
  22. 22. J & J Study Summary • Measured TML values may either increase or decrease as materials become coarser, • If the TML value is measured using >5 mm top size: • overall moisture content of the whole material is below the TML value determined for 12mm x 0mm • moisture content of the <5 mm could be above the TML value determined for 12mm x 0mm • May even be above the 5mm x 0mm determined TML value. Bulk Solids: Science / Engineering / Design
  23. 23. J & J Study Summary TML = 8.8% TML = 8.6% 5mm x 0mm 12mmx 0mm Bulk Solids: Science / Engineering / Design
  24. 24. J & J Study Conclusion • Iron ores shipped in other locations around the globe at >TML values measured. • If the standard is changed to include, as an example, TML determination at 80% or 85% of saturation, then care must be taken. • The fines present in the sample might be even closer to their liquefaction value especially if >5 mm are included in the determination of the TML value More research needs to be done to investigate this issue Bulk Solids: Science / Engineering / Design
  25. 25. Questions? Corin Holmes, MSc Eng Technical Officer Jenike & Johanson Perth, WA cholmes@jenike.com Bulk Solids: Science / Engineering / Design
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