Modified Proctor/Fagerberg Test for Iron Ore Fines

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The Modified Proctor/Fagerberg Test for Iron Ore Fines, sometimes abbreviated as PFD80 or D80, refers to one of the five methods used to determine the Transportable Moisture Limit (TML) of Group A or liquefiable solid bulk cargoes. One other method is the Modified Proctor/Fagerberg Test for Coal[1] and the three other test methods are the Penetration Test (PT), Flow Table Test (FTT) and the standard Proctor/Fagerberg Test (PFT) stated in Appendix 2 of the IMSBC Code[2].

There are two versions of the Modified Proctor/Fagerberg Test (MPFT) known as the Modified Proctor/Fagerberg Test for Iron Ore Fines[3] and the Modified Proctor/Fagerberg Test for Coal[1]. These two methods have not yet been implemented in the International Maritime Solid Bulk Cargoes Code (IMSBC Code) but have been implemented on a voluntary basis in some countries. Contact your relevant authority to determine if the Modified Proctor/Fagerberg Test for Iron Ore Fines can be used to determine the Transportable Moisture Limit (TML) of Group A or liquefiable Iron Ore Fines.

See Also: Modified Proctor/Fagerberg Test for Coal

Note: All information contained within these boxes were obtained from DSC.1/Circ.71 - Early Implementation of Draft Amendments to the IMSBC Code Related to the Carriage and Testing of Iron Ore Fines, 15 November 2013, London. (Download PDF)[3].


Note: All information contained within these boxes are collaborative notes and not specifically recommended in DSC.1/Circ.71[3].


Note: Please refer to the latest edition of the International Maritime Solid Bulk Cargoes Code (IMSBC Code) before performing the test described below.


History[edit]

The Proctor/Fagerberg test was first published in Stockholm in 1962 by Bengt Fagerberg and Kjell Eriksson[5] as part of a committee established by the Swedish Mining Association and several Scandinavian mining companies. The committee was given the task to develop a simple method for determining the critical moisture content (CMC) of individual cargoes [6]. The test method is based upon use of the Proctor apparatus developed in soil mechanics [7] The standard Proctor/Fagerberg test was adopted by the International Maritime Organization, for use in the IMSBC Code, between 1991 and 1998 [8][9].

After the temporary reclassification of Iron Ore Fines (IOF) in 2011[10] research and industry associations, such as the Iron Ore Technical Working Group, began studies to determine the applicability of the three test methods stated in the International Maritime Solid Bulk Cargoes Code (IMSBC Code). The outcome of this research, in 2013, was to implement the Modified Proctor/Fagerberg Test for Iron Ore Fines.[11][3][12][13][14][15][16].

The circular DSC.1/Circ.71 states that although more research is required, the Modified Proctor/Fagerberg Test for Iron Ore Fines will be introduced in amendment 03-15 of the IMSBC Code in 2015, on a voluntary basis, and entered into force on January 1, 2017.[8][3][17]. The circular DSC.1/Circ.71 has been been voluntarily adopted by the governments of Brazil, Australia and the Marshall Islands[18].

Timeline[edit]

Year Document Test Method Development Reference(s)
1962 Fuktighetens Inflytande pa Sligtransporter Till Sjoss Standard Proctor/Fagerberg Test (PFT) Published [5][6][9]
1965 Hazards of Shipping Granular Ore Concentrates (Part 1 and 2) Standard Proctor/Fagerberg Test (PFT) Published [19][11]
1971 Determination of Critical Moisture Contents in Ore Concentrates Carried in Cargo Vessels Standard Proctor/Fagerberg Test (PFT) Published [6][9]
1991 to 1998 Code of Safe Practice for Solid Bulk Cargoes (BC Code) Standard Proctor/Fagerberg Test (PFT) Introduced [2][11]
2011 Carriage of Iron ore Fines that May Liquefy N/A Reclassification of IOF [10]
2013 Iron Ore Technical Working Group Submission for Evaluation and Verification, ‘Terms of Reference 1’ Modified Proctor/Fagerberg Test for Iron Ore Fines Report Released [12]
2013 Iron Ore Technical Working Group Submission for Evaluation and Verification, Marine Report Modified Proctor/Fagerberg Test for Iron Ore Fines Report Released [13]
2013 Iron Ore Technical Working Group Submission for Evaluation and Verification, Iron Ore Fines Proctor-Fagerberg Test Modified Proctor/Fagerberg Test for Iron Ore Fines Report Released [14]
2013 Iron Ore Technical Working Group Submission for Evaluation and Verification, Reference Tests Modified Proctor/Fagerberg Test for Iron Ore Fines Report Released [15]
2013 Iron Ore Technical Working Group Submission for Verification, Research Synopsis and Recommendations Modified Proctor/Fagerberg Test for Iron Ore Fines Report Released [16]
2013 Early Implementation of Draft Amendments to the IMSBC Code Related to the Carriage and Testing of Iron Ore Fines Modified Proctor/Fagerberg Test for Iron Ore Fines Introduced Voluntarily (Some Countries) [3]
2015 MSC 95/22/Add.2 - Amendments to the International Maritime Solid Bulk Cargoes Code (IMSBC Code) Modified Proctor/Fagerberg Test for Iron Ore Fines Introduced Voluntarily in Amendment [20][17]
2017 International Maritime Solid Bulk Cargoes Code (IMSBC Code) Modified Proctor/Fagerberg Test for Iron Ore Fines To be introduced on a mandatory basis into the IMSBC Code [20][3]

Scope[edit]

Unlike the standard Proctor/Fagerberg test, where the Transportable Moisture Limit (TML) is taken as equal to the critical moisture content at 70% degree of saturation, the Modified Proctor/Fagerberg Test for Iron Ore Fines takes the TML as equal to the critical moisture content at 80% degree of saturation.

  1. The test procedure specified in this section (this test) should only be used for determining transportable moisture limit (TML) of Iron Ore Fines. See individual schedule for Iron Ore Fines.
  2. Iron Ore Fines is iron ore containing both:
    1. 10% or more of fine particles less than 1 mm, and
    2. 50% or more of particles less than 10 mm.
  3. The TML of Iron Ore Fines is taken as equal to the critical moisture content at 80% degree of saturation according to the modified Proctor/Fagerberg method test.
  4. The test procedure is applicable when the degree of saturation corresponding to Optimum Moisture Content (OMC) is 90% or higher.

Apparatus[edit]

Modified Proctor/Fagerberg Apparatus for Iron Ore Fines (figure 1.4.1 in MSC 95/3/Add.1)
  1. The Proctor apparatus (see figure 1.4.1) consists of a cylindrical iron mould with a removable extension piece (the compaction cylinder) and a compaction tool guided by a pipe open at its lower end (the compaction hammer).
  2. Scales and weights and suitable sample containers (See section 3.2 of Appendix 2 of the IMSBC Code).
  3. A drying oven with a controlled temperature interval from 100oC to maximum 105oC. This oven should be without air circulation.
  4. A container for hand mixing. Care should be taken to ensure that the mixing process does not reduce the particle size by breakage or increase the particle size by agglomeration or consistency of the test material.
  5. A gas or water pycnometry equipment to determine the density of the solid material as per a recognized standard (e.g. ASTM D5550, AS1289, etc.)

Temperature and Humidity[edit]

It is preferable to work in a room where the samples will be protected from excessive temperatures, air currents and humidity variations. All phases of the material preparation and testing procedure should be accomplished in a reasonable space of time to minimize moisture losses and, in any event, within the day of commencement. Where possible, sample containers should be covered with plastic film or other suitable cover.


Procedure[edit]

Establishment of a Complete Compaction Curve[edit]

A representative sample according to a relevant standard (see section 4.7, page 20 of the IMSBC Code) of the test material is dried at a temperature of approximately 60oC or less to reduce the samples moisture to suitable starting moisture, if needed. The representative sample for this test should not be fully dried, except in case of moisture content measurement.

The total quantity of the test material should be at least three times as big as required for the complete test sequence. Compaction tests are executed for five to ten different moisture contents (five to ten separate tests). The samples are adjusted in order that dry to almost saturated (plastic) samples are obtained. The required quantity per compaction test is about 2000 cm3.


At each compaction test a suitable amount of water is added to the sample of the test material. The sample material is gently mixed before being allowed to rest and equilibrate. Approximately one fifth of the mixed sample is filled into the mould and levelled and then the increment is tamped uniformly over the surface of the increment. Tamping is executed by dropping a 150 g hammer 25 times through the guide pipe, 0.15 m each time. The performance is repeated for all five layers. When the last layer has been tamped, the extension piece is removed and the sample is levelled off along the brim of the mould with care, ensuring to remove any large particles that may hinder levelling of the sample, replacing them with material contained in the extension piece and re-levelling.

When the weight of the cylinder with the tamped sample has been determined, the cylinder is emptied, the sample is dried at 105oC and the weight is determined. Reference is made to ISO 3087:2011 "Iron ores – Determination of the moisture content of a lot". The test then is repeated for the other samples with different moisture contents.

Density of solid material should be measured using a gas or water pycnometry equipment according to internationally or nationally accepted standard, e.g. ASTM D5550 and AS 1289.


It is noted:

  1. It is necessary to control the total amount of soil compacted since, if the amount of soil struck off after removing the collar is too great, the test results will be inaccurate as the energy input will not be within the required tolerances. Some large particles may protrude a little more than 5 mm above the surface for the passing 37.5 mm material. Suitable allowances in the trimming process must be made for these particles but the average height of the compacted sample before trimming should not exceed 5 mm above the mould[21].
  2. While trimming the surface of the sample, the procedure may depend on the characteristics of the soil[21]:
    1. Essentially fine-grained soil - Trim the compacted soil level with the top of the mould by means of the straightedge; use smaller size material to patch any holes developed in the surface from removal of coarse material during trimming.
    2. Soil containing stones - Trim the compacted soil in the mould ensuring that portions of stones standing above the top of the mould are compensated by hollows of about the same volume below the top of the mould.
  3. It is not recommended to reuse material that has been placed in the oven for the determination of moisture content. When the sample is placed into the oven the heat damages the particles, reduces the ability for the material to retake water and will reduce the accuracy of the results if reused.

Definitions and Data for Calculations[edit]

empty cylinder, mass in grams: A

cylinder with tamped sample, mass in grams: B

wet sample, mass in grams: C

C = B -– A

dry sample, mass in grams: D

water, mass in grams (equivalent to volume in cm3): E

E = C –- D

Volume of cylinder: 1000 cm3


It is noted to use the exact volume of the mould that has been measured directly using a vernier caliper. Using 1000 cm3, as stated above, might lead to inaccurate results if the volume of the mould is not exactly 1000 cm3, which they rarely are.


Calculation of Main Characteristics[edit]

density of solid material, g/cm3 (t/m3): d

dry bulk density, g/cm3 (t/m3): γ

γ = D / 1000

net water content, volume %: ev

ev = E / D x 100 x d

void ratio: e (volume of voids divided by volume of solids)

e = d / γ - 1

degree of saturation, percentage by volume: S

S = ev / e

gross water content, percentage by mass: W1

W1 = E / C x 100

net water content, percentage by mass: W

W = E / D x 100

It is noted that by using the above equations the operator must remove the entire sample from the mould to determine the bulk density (i.e. γ = D / 1000). This is not recommended as there will always be residue from the sample left within the mould.

The below equations may assist, along with the above, in calculating the main characteristics:

Note that this method involves first calculating the net water content by weight and then converting to the gross water content by weight, which is what the Transportable Moisture Limit (TML) is reported in.

The following equation is used to determine the bulk density of the sample:

Pftbulkdensity.gif

Where:

m1 = is mass of mould and base plate (in g),
m2 = is mass of mould, base plate and compacted sample (in g),
ρb = is the bulk density of each compacted specimen (in t/m3) and
V = is internal volume of the mould (in cm3).

The following equation is used to determine the net water content by weight:

Eqn (4).png

Where:

w = net water content by weight (%),
m3 = is mass of container and wet sample (in g),
m4 = is mass of container and dry sample (in g),
m5 = is mass of container (in g),
Ww = mass of water and
Ws = mass of solids.

The following equation is used to determine the dry density of the sample:

Pftdrydensitynew.png

Where:

w = net water content by weight of each compacted specimen (%),
ρb = is the bulk density of each compacted specimen (in t/m3) and
ρd = is the dry density of each compacted specimen (in t/m3).

The following equation is used to determine the void ratio of the sample:

Pftvoidratio.gif

Where:

e= void ratio of each compacted specimen,
ρst = is the specific gravity of the sample (in t/m3) and
ρd = is the dry density of each compacted specimen (in t/m3).

To convert the net water content by weight to the gross water content by weight the following equation can be used:

Gwctonwcwithw.png

Where:

w1 = gross water content by weight (%) and
w = net water content by weight (%).

You can also use the converter provided on the main site by clicking the following link:

http://tmltesting.com/calc-moisturecontent.php

The following equation is used to determine the void ratio at different gross water contents for corresponding degrees of saturation:

Voidratiocalculationwithgwc.png

Where:

e = void ratio,
w1 = gross water content by weight (%),
ρst = is the specific gravity of the sample (in t/m3) and
S = degree of saturation (%).

You can also use the calculators provided on the main site by clicking the following link:

http://tmltesting.com/other.php


Presentation of the Compaction Tests[edit]

Graphical representation of the compaction curve produced during the Modified Proctor/Fagerberg Test for Iron Ore Fines (figure 1.4.3 in MSC 95/3/Add.1)

For each compaction test the calculated void ratio (e) value is plotted as the ordinate in a diagram with net water content (ev) and degree of saturation (S) as the respective abscissa parameters.


It is noted that since the Transportable Moisture Limit is determined in the gross water content by weight, similar to the Penetration Test and Flow Table Test, the void ratio should be plotted against the gross water content by weight.


Compaction Curve[edit]

The test sequence results in a specific compaction curve (see figure 1.4.3).

The critical moisture content is indicated by the intersection of the compaction curve and the line S = 80% degree of saturation. The transportable moisture limit (TML) is the critical moisture content.

Optimum Moisture Content (OMC) is the moisture content corresponding to the maximum compaction (maximum dry density) under the specified compaction condition. To check the applicability of this test, the relationship between moisture content and dry density should be evaluated, during this test. Then the OMC and the corresponding degree of saturation should be determined. This test procedure was developed based on the finding that the degree of saturation corresponding to OMC of iron ore fines was 90 to 95%, while such degree of saturation of mineral concentrates was 70% to 75%. In the case that the degree of saturation corresponding to OMC is less than 90%, the shipper should consult with an appropriate authority, for the reason that this test may not be applicable for the material and the TML determined by this test may be too high.


Discussion[edit]

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References[edit]

  1. 1.0 1.1 Modified Proctor/Fagerberg Method for Coal, 24 November 2014. (Download PDF)
  2. 2.0 2.1 International Maritime Organisation, International Maritime Solid Bulk Cargoes Code, 2013 Edition, London: International Maritime Organization.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 International Maritime Organisation, DSC.1/Circ.71 - Early Implementation of Draft Amendments to the IMSBC Code Related to the Carriage and Testing of Iron Ore Fines, 15 November 2013, London. (Download PDF)
  4. Munro, M., & Mohajerani, A. (2016). Moisture Content Limits of Iron Ore Fines to Prevent Liquefaction During Transport: Review and Experimental Study. International Journal of Mineral Processing, 148. doi: http://dx.doi.org/10.1016/j.minpro.2016.01.019
  5. 5.0 5.1 Fagerberg, B., Eriksson K., Fuktighetens Inflytande pa Sligtransporter Till Sjoss, 1962. (Download PDF)
  6. 6.0 6.1 6.2 Fagerberg, B., Determination of Critical Moisture Contents in Ore Concentrates Carried in Cargo Vessels. Minerals Transportation, 1971: p. 174-191. (Download PDF)
  7. American Society for Testing and Materials, ASTM Designation D698 - Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort. 2012.
  8. 8.0 8.1 Munro, M. and A. Mohajerani, Moisture Content Limits of Iron Ore Fines to Prevent Liquefaction During Transportation. International Journal of Mineral Processing.
  9. 9.0 9.1 9.2 Munro, M. and A. Mohajerani, Determination of Transportable Moisture Limit of Iron Ore Fines for the Prevention of Liquefaction in Bulk Carriers. Marine Structures, 2015. 40(1): p. 193-224.
  10. 10.0 10.1 “Carriage of Iron ore Fines that May Liquefy,” International Maritime Organization, DSC.1/Circ66, London, 2011. (Download PDF)
  11. 11.0 11.1 11.2 Munro, M. and A. Mohajerani, Moisture Content Limits of Iron Ore Fines to Prevent Liquefaction During Transportation. International Journal of Mineral Processing.
  12. 12.0 12.1 Iron Ore Technical Working Group (TWG), TWG Terms of Reference 1 - Iron Ore Technical Working Group Submission for Evaluation and Verification, ‘Terms of Reference 1’, 15 February 2013. (Download PDF)
  13. 13.0 13.1 Iron Ore Technical Working Group (TWG), TWG Marine Report - Iron Ore Technical Working Group Submission for Evaluation and Verification, Marine Report, April 2013. (Download PDF)
  14. 14.0 14.1 Iron Ore Technical Working Group (TWG), TWG Iron Ore Fines Proctor-Fagerberg Test - Iron Ore Technical Working Group Submission for Evaluation and Verification, Iron Ore Fines Proctor-Fagerberg Test, May 2013. (Download PDF)
  15. 15.0 15.1 Iron Ore Technical Working Group (TWG), TWG Reference Tests - Iron Ore Technical Working Group Submission for Evaluation and Verification, Reference Tests, May 2013. (Download PDF)
  16. 16.0 16.1 Iron Ore Technical Working Group (TWG), TWG Research Synopsis and Recommendations - Iron Ore Technical Working Group Submission for Verification, Research Synopsis and Recommendations, June 2013. (Download PDF)
  17. 17.0 17.1 International Maritime Organisation, MSC 95/3/Add.1 - Amendments to the International Maritime Solid Bulk Cargoes Code (IMSBC Code), 26 January 2015, London. (Download PDF)
  18. http://www.ukpandi.com/knowledge/article/new-amendments-02-13-and-03-15-to-imsbc-code-affecting-group-a-cargoes-130748/
  19. Fagerberg, B., Hazards of Shipping Granular Ore Concentrates (Part 1 and 2), Canadian Mining Journal, vol.856, pp. 53-57,81-86.
  20. 20.0 20.1 International Maritime Organisation, MSC 95/22/Add.2 - Amendments to the International Maritime Solid Bulk Cargoes Code (IMSBC Code), Resolution MSC.393(95) Annex 3, adopted on 11 June 2015, London. (Download PDF)
  21. 21.0 21.1 Standards Australia, AS 1289.5.1.1-2003 - Soil compaction and density tests - Determination of the dry density/moisture content relation of a soil using standard compactive effort. 2003.

See Also[edit]

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