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HomeBreaking NewsAs African Minerals discovers another 5 billion tonnes, Sierra Leone becomes largest iron ore deposit in the world!

As African Minerals discovers another 5 billion tonnes, Sierra Leone becomes largest iron ore deposit in the world!

As African Minerals discovers another 5 billion tonnes, Sierra Leone becomes largest iron ore deposit in the world!

Tonkolili magnetite iron ore mineral resource grows to 10.5 billion tonnes.  Magnetite test work confirms high quality iron concentrate. (Photo: Frank Timis, Executive Chairman, African Minerals)

Total JORC compliant iron ore mineral resource at Tonkolili grows to 10.5 billion tonnes – the world’s largest reported JORC compliant magnetite iron ore mineral resource

  • 9.7 billion tonnes of the JORC-compliant mineral resource has an average in situ grade of 30.1% iron, with the balance of 0.8 billion tonnes grading 16.8% iron in situ
  • 20 tonnes of metallurgical sample have undergone extensive test work at AMMTEC. A tonnage scale pilot plant test has confirmed that Tonkolili magnetite is upgradable to a very high grade iron ore concentrate at a final grind size of 38µ. This iron ore concentrate has a grade of 70.3% Fe at a mass recovery of 26.5% and contains low levels of impurities
  • £80m fund raising completed for the Phase 1 Hematite Development and Production Project
  • Due diligence with China Railway Materials Commercial Corporation (“CRM”) progressing well. Company expecting to finalise transaction in March 2010
  • Targeting commercial production of Phase 1 Hematite iron ore in Q1 2011
  • DFS study to be completed in Q2 2010

African Minerals Limited (AIM:AMI) the mineral exploration and development company with significant iron ore and base metal interests in Sierra Leone, West Africa, is pleased to announce an updated magnetite iron ore Mineral Resource Estimate for its flagship iron ore project at Tonkolili in Sierra Leone (the “Project”). The updated Mineral Resource Estimate was prepared by independent consultants SRK Consulting (UK) Ltd (“SRK”), and complies with the 2004 edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, (the JORC Code1).

The update reflects additional drill-hole and assay data completed since the preparation of the last Mineral Resource Estimate reported on the 19th May 2009. The update now incorporates a Mineral Resource Estimate for the Kasafoni deposit, and updated Mineral Resource Estimates for the Numbara, Simbili and Marampon deposits.

Metallurgical testwork performed by independent consultants AMMTEC Ltd (“AMMTEC”) is also reported, confirming the amenability of Tonkolili magnetite iron ore to the production of high grade iron ore concentrates using established metallurgical processes.

MAGNETITE IRON ORE MINERAL RESOURCE

African Minerals has completed over 110,000m of diamond drilling across Numbara, Simbili, Marampon, and the newly reported Kasafoni deposit, which is located along strike to the north of Numbara.  A total of 90,893 diamond drill metres were utilised by SRK in preparing the updated Mineral Resource Estimate, and excluded geotechnical and metallurgical drill holes which were reserved for use in these respective technical disciplines.

The updated Mineral Resource Estimate is 10.5 billion tonnes at an average in situ grade of 29.0% iron. This exceeds the Company’s target mineral resource of 10 billion tonnes for the current phase of resource development. Included within the 10.5 billion tonnes are 9.7 billion tonnes at an average grade of 30.1% iron in situ.

This Mineral Resource Estimate is reported over a strike length of 20km, and includes holes completed up to 26th January 2010. Drilling has continued with up to four core rigs to test high grade BIF targets in the Kasafoni West area. The Company expects to update the Mineral Resource Estimate upon completion of this work in the near future.

SRK has reported 6.1 billion tonnes of the Mineral Resource in the Indicated category with an average in situ grade of 29.5% iron, and 4.4 billion tonnes in the Inferred category with an average in situ grade of 28.3% iron. 

The Mineral Resource from these four deposits is summarised in Table 1:

1 The Joint Ore Reserves Committee of The Australasian Institute of Mining and Metallurgy, Australian Institute of Geoscientists and Minerals Council of Australia 

DEPOSIT

RESOURCE CATEGORY

TONNES (Bt)

Fe_TOT %

Fe_MAG %

SiO2 %

AL2O3 %

P

%

Numbara INDICATED

2.5

28.5

23.7

46.2

5.6

0.05

INFERRED

1.5

27.8

22.9

46.6

6.0

0.06

TOTAL

4.0

28.2

23.4

46.3

5.8

0.05

Marampon INDICATED

0.5

29.0

26.3

40.0

12.6

0.56

INFERRED

0.2

30.1

27.1

44.9

5.4

0.13

TOTAL

0.7

29.3

26.6

41.6

10.3

0.42

Simbili INDICATED

2.2

29.8

25.6

45.3

4.8

0.05

INFERRED

0.7

28.8

23.7

45.9

5.3

0.05

TOTAL

2.8

29.6

25.1

45.5

4.9

0.05

Kasafoni INDICATED

0.9

32.1

30.3

43.8

6.2

0.05

INFERRED

2.0

28.3

25.6

45.6

7.0

0.05

TOTAL

2.9

29.5

27.1

45.0

6.7

0.05

TOTAL INDICATED

6.1

29.5

25.6

45.0

6.0

0.09

TOTAL INFERRED

4.4

28.3

24.5

45.9

6.3

0.06

TOTAL

10.5

29.0

25.1

45.4

6.1

0.08

Table 1. Tonkolili Magnetite Mineral Resource Summary

Notes: All results are rounded to one decimal place, except Phosphorous (P) which is rounded to two decimal places.  Any differences between totals and sub-totals are a function of rounding

SRK’s full resource estimation report will be made available the week commencing the 1st March 2010 on the Company’s web-site at www.african-minerals.com.

MAGNETITE IRON ORE METALLURGY

Detailed metallurgical test work has been completed by AMMTEC on 20 tonnes of Tonkolili magnetite iron ore to identify an optimal mineral processing circuit to produce a high quality magnetite concentrates for sale. This work featured several tonnage scale pilot plant runs that have been used to define process design criteria for the Definitive Feasibility Study (“DFS”). Metallurgical test work also included ore characterisation by the CSIRO Iron Ore Group, and additional laboratory and industrial testwork by AMMTEC.

The process design criteria for the DFS comprise a conventional metallurgical circuit using the proven technologies of Low Intensity Magnetic Separation (“LIMS”) and flotation. Pilot plant runs on composites of the main magnetite Banded Iron Formation (“BIF”) zones provided these design criteria for processing Tonkolili magnetite ores yielding very high grade concentrates which are summarised in Table 2.

Grind Size P80

Mass (%)

Fe (%)

SiO2 (%)

Al2O3 (%)

P (%)

Plant feed

100.0

30.7

44.7

4.5

0.04

38µ

26.5

70.3

2.95

0.43

0.01

 

 

Table 2. Tonkolili Magnetite Plant Feed and Concentrate grades for main BIF composites

Staged crushing and grinding for the reported concentrates progressively removes tailings at the coarsest possible particle size, which minimizes energy consumption, with more than 45% of the feed is removed at coarser size fractions, leaving less than 55% of the feed sample for final grinding.

This testwork yields excellent results that have exceeded the Company’s predictions of iron grade, mass recovery and impurities removal, and provides a robust basis for the progression of the DFS which is now underway.

CHINA RAILWAY MATERIALS COMMERCIAL CORPORATION (“CRM”)

Negotiations with CRM in respect of the planned investment by CRM in the Company announced on the 6th January 2010 are progressing well. In 2009 CRM was ranked 57th among the top 500 State Owned Enterprises in China. Subject to the finalisation of terms, in March 2010 African Minerals expects to execute definitive agreements for long term iron ore off-take by CRM, the investment by CRM and the procurement of equipment and services relating to the Project.

£80M CASH PLACING

On the 11th February 2010 the Company announced completion of the £80m cash placing (the “Placing”) with institutional investors. The proceeds of the Placing are to be used to commence construction of key infrastructure for Phase 1 of the Project, the production of up to 8 million tonnes per annum of hematite iron ore.

HEMATITE IRON ORE PRODUCTION

The Company is targeting delivery of commercial production of hematite iron ore in Q1 2011 and work is progressing well on defining a hematite resource with SRK. AML is therefore focusing its management and technical resources on that early target. The AML management team, with its proven track record of delivering such projects within tight time frames, is confident of its ability to deliver on this goal. As a consequence, AML’s board has elected to push back delivery of the DFS for the magnetite Project, being prepared by Worley Parsons, to Q2 2010, allowing the Company to focus all its resources on delivery of the Phase 1 hematite project.

All assay, geological, metallurgical and Mineral Resource Estimate work referred to in this announcement was undertaken and/or verified by independent experts.

Commenting on the Mineral Resource Estimate and Project Update, Alan Watling, Chief Executive Officer of AML said:

“I am delighted with our progress at Tonkolili. We have doubled the size of the resource having completed what we believe to be the largest exploration programme in Africa during 2008 and 2009, Tonkolili is now firmly in place as the largest reported JORC compliant magnetite iron ore mineral resource in the world2.

Furthermore, independent industrial pilot metallurgical testwork demonstrates that a premium quality product can be produced with very high grades and low levels of impurities.

2Source: SRK Consulting (UK) Ltd

The combination of the size and quality of iron ore concentrate produced at pilot plant scale, together with close proximity to railway and port infrastructure over which the Company has a 99 year lease, certainly provides the platform for a stand-out project.

I am confident that the Company’s experienced management team will deliver on the targets we are setting ourselves. Coupled with the market forecast of significant increases in iron ore prices in the next two years, we are in a very strong position to realise the full potential of the Project and to compete alongside leading iron ore producers in supplying international steel markets.”

Qualified Persons

The information in this press release that relates to Mineral Resources is based on information compiled under the direction of Mr Howard Baker, who is a Member the Australasian Institute of Mining and Metallurgy (“AusIMM”).

Mr Baker is a full time employee of SRK and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2004 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’.  Mr Howard Baker has reviewed this press release and consents to the inclusion in the press release of the matters based on his information in the form and context in which this appears.

The information in this press release that relates to magnetite metallurgy is based on information compiled and reviewed by Rodney Elvish, who is a Fellow and CPMet of the Australasian Institute of Mining and Metallurgy (“AusIMM”).  Mr. Elvish is an independent consultant to the Company, and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2004 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Mr Elvish has reviewed this press release and consents to the inclusion in the press release of the matters based on his information in the form and context in which this appears.

The information in this press release that relates to geological exploration is based on information compiled and reviewed by Marcus Reston, who is a Fellow of the Geological Society of London (“FGS”), and a Member of the Australian Institute of Geoscientists (“AIG”).  Mr. Reston, Project Manager: Tonkolili Iron Ore, is a full-time employee of the Company and meets the requirements of a “Qualified Person” under the AIM Guidance Note on Mining, Oil and Gas dated June 2009. Mr. Reston has reviewed this press release and has consented to the inclusion in this press release of the matters based on his information in the form and context in which this appears.

In addition to the above, the press release as a whole has been compiled under the direction of Dr Mike Armitage, who is a Chartered Engineer and a Chartered Geologist and a Member of the Institute of Materials, Minerals and Mining. Dr Armitage is a full time employee of SRK Consulting (UK) Ltd and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2004 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Dr Armitage has reviewed this press release and consents to the inclusion in the press release of the matters based on his information in the form and context in which this appears.

Enquiries: 

African Minerals Limited Tel: +44 (0)1481 726833
Frank Timis  
Alan Watling  
   
Canaccord Adams Limited Tel: +44 (0)20 7050 6500
Robert Finlay  
Mike Jones  
   
Mirabaud Securities Limited Tel: +44 (0)20 7878 3360
Rory Scott  
Pav Sanghera  
   
   
Pelham Bell Pottinger Tel: +44 (0)20 7337 1500
Charles Vivian  
Klara Kaczmarek  

 

GLOSSARY

JORC The Joint Ore Reserves Committee of The Australasian Institute of Mining and Metallurgy, Australian Institute of Geoscientists and Minerals Council of Australia
Magnetite Iron oxide of the form Fe3O4
Hematite Iron oxide of the form Fe2O3
DFS Definitive Feasibility Study
JORC Code 2004 edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves
Mineral Resource A concentration or occurrence of material of intrinsic economic interest in or on the Earth’s crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge. Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories
Indicated Mineral Resource That part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed
Inferred Mineral Resource That part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence. It is inferred from geological evidence and assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes which may be limited or of uncertain quality and reliability
Bt Billion Tonnes
Fe Iron
Fe_TOT Iron contained in magnetite and other minerals
Fe_MAG Iron contained in magnetite
SiO2 Silica; Silicon Dioxide
Al2O3 Alumina; Aluminium Oxide
P Phosphorous
Pilot Plant A mineral processing system which is operated to generate information about the behaviour of the system and for use in design of larger facilities
Low Intensity Magnetic Separation Metallurgical processing technique utilising low intensity electromagnetic fields to separate magnetic from non-magnetic particles
Flotation A metallurgical processing method for the concentration and separation of fine-grained minerals taking advantage of the different physicochemical surface properties of the minerals
This information is provided by RNS
The company news service from the London Stock Exchange

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