BMR Minint Tailings Stockpiles

Tailings stockpiles

BMR has acquired all the stockpiles of tailings at the Kabwe mine complex. These assets are held by Enviro Mining Ltd, which is a wholly-owned subsidiary of BMR, and its two Zambian-registered subsidiaries, Enviro Processing Ltd and Enviro Props Ltd.

Enviro Processing Ltd holds the Small Scale Licence 7081-HQ-SML (edged in blue on the plan below) in respect of the tailings on Stand 5187 (edged in black on the Plan) and the Large Scale Licence 6990-HQ-LML (formerly known as ML1) applying to the whole 703 hectares of the BMR site.

The Plan of the stockpiles acquired, comprising Stand 5187and the slag dump 57, is illustrated below, together with an aerial photograph.

Tailings-Licence-area.jpg kabwe-mine-satellite.jpg


The Wash Plant Tailings Dump

The wash plant tailings dumps include process residue historically produced at Kabwe prior to its closure through the washing of newly mined and crushed ore. These have a high combined grade of lead and zinc at 17.87%.

The Mineral Corporation Consultancy (Pty) Ltd has produced for BMR a JORC-compliant mineral resources estimate for the wash plant tailings. The report was prepared by Mr D R Young (BSc. Hons., Geology), who is a Competent Person as defined by the JORC Code (2004) and is a registered scientist on the database of the South African Council for National Scientific Professors (SACNASP), with more than five years' experience relevant to resource estimation.

JORC Mineral Resource estimates on Zinc (Zn) and Lead (Pb) for the Kabwe washplant tailings are:

Mineral Resource Class Volume
(m3)
Dry Bulk Density (t/m3) Zn
(%)
Pb
(%)
Dry Tonnage Contained Tons of Metal – Zinc Contained Tons of Metal – Lead
Measured 304,771 1.92 10.66 7.21 573,458 61,147 41,345

 

Washplant_Tailings_at_Kabwe.JPG

Washplant Tailings at Kabwe.

The Leach Plant Residue

Following the JORC Mineral Resources estimate published for the washplant tailings at Kabwe above, The Mineral Corporation Consultancy has also published a first JORC estimate report for the central section of the leachplant tailings. This section is where the auger drilling carried out in July 2010 has provided JORC-compliant assayable results.

This report was also prepared by Mr D R Young.

The JORC Mineral Resource estimates on Zinc (Zn) and Lead (Pb) for the central section of the leachplant tailings are:

Mineral Resource Classification Zn
(%)
Pb
(%)
Dry Tonnage Contained Tons of Metal – Zinc Contained Tons of Metal – Lead
Measured 3.88 8.71 2,648,920 102,690 230,810

The aggregate stockpile inventory, including all above-ground stockpiles at the Kabwe site, is as follows:

 

Summary of Stockpile Volume Inventory

Stockpile Type Dry Tonnage Grade %
Zinc
Grade %
Lead
Contained Tons of Metal – Zinc Contained Tons of Metal – Lead
Waelz Slag 1,104,794 3.64 1.52 40,189 16,794
ISF Slag 1,481,563 8.07 1.22 119,579 18,026
Mixed Leachplant 249,690 6.71 10.17 16,760 25,393
Pyrite Tailings 333,508 4.86 5.66 16,208 18,877
Blue Powder 1,914 14.10 7.34 270 141
Non-JORC total 3,171,469     193,006 79,231
Washplant (JORC) 573,458 10.66 7.21 61,147 41,345
Central leachplant (JORC) 2,648,920 3.88 8.71 102,690 230,810
Grand total 6,393,847 5.48 5.50 356,843 351,386

 

Auger_drilling_of_slag_tailings_for_sampling_and_assaying_processes.JPG

Auger drilling of slag tailings for sampling and assaying processes.

Other Mineral Resources

BMR has acquired all the previously-mined and the unmined portion of the resource at the former Kabwe mine following its closure in 1994, covered by the Large Scale Mining Licence (6990-HQ-LML, edged in blue on the map below). It should be noted that the Large Scale Mining Licence is encroached on by two Small Scale licences.  BMR is taking steps to resolve these issues with the Ministry of Mines.

No_1_Ore_Shaft_at_Kabwe.JPG

Headgear of the
No. 1 ore shaft

Kabwe-Project-Orebody-Locat.jpg

Click here to enlarge image

BMR has received from The Mineral Corporation Consultancy a technical review of the potential underground ore resources at the Kabwe mine. The Mineral Corporation Consultancy has reviewed these estimates and established the tonnage potential for the main selected ore bodies as follows:


Ore Body

Ore Max Depth (m)

Total Tons

Grade Zinc
(%)

Grade Lead
(%)

Contained Tons of Metal – Zinc

Contained Tons of Metal – Lead

Old Airfield

150

46,460,000

2.23

0.80

1,036,058

371,680

Speaks

200

1,944,000

12.00

2.00

233,280

38,880

Number two Ore body

470

1,905,159

12.86

1.77

245,003

33,721

Mine Club

200

666,000

11.77

0.83

78,388

5,528

Total

 

50,975,159

3.12

0.89

1,592,730

449,809

These estimates have not been compiled to a recognised international reporting standard such as JORC and cannot therefore be relied upon.

The bulk of the mineralisation of the underground resource is characterised by the occurrence of carbonate-hosted Pb-Zn orebodies as cores of massive sulphide orebodies surrounded by oxide zones (silicate ore). Disseminated low grade mineralisation also occurs locally at Kabwe and this is often overlain by high grade lateritic silicate ore (blanket ore).

At current metal prices, the prospect of re-opening the underground mine is remote.

 

View_of_the_Kabwe_Concentrator_Plant_and_offices_from_the_No._1_Ore_Shaft.JPG

View of the Kabwe concentrator plant and offices from the No.1 ore shaft.

ISF Slag

The ISF comprises a valuable resource for the company. The tonnage and grade established by Mineral Corporation Consultancy was 1,481,563 tonnes @ 8.07 Zn and 1.22Pb. To realise the potential of this resource, BMR has embarked on a metallurgical test programme to investigate the recovery of the contained Zn and at the same time to explore the possibility of integrating any such process with the acid/brine leach process.

Waelz Kiln Slag (WKS)

This resource is uneconomic to treat for the recovery of Zn and Pb.
Trials by reputable building research establishments in Germany and the United Kingdom have successfully combined WKS with regular building sand (typically 80%:20% ratio) to produce industry compliant building blocks and cement. BMR has produced test WKS/sand building blocks in Zambia, and is making application to ZEMA for an Environmental Project Bulletin (EPB) to sell this material locally. Once approval is granted this will provide the Company with an additional income and provide an elegant solution to an historic environmental issue.

Exploration Potential

A comprehensive review of the historic geological data and exploration campaigns covering the Kashitu (south eastern end) of the Large Scale Mining Licence has been undertaken. The results indicate encouraging surface Zn enrichment warranting a follow up geological investigation programme.

However, the results from the previous, limited number of deeper Diamond Drill holes intended to explore the possible extension of the main Kabwe orebody at depth are inconclusive.

It should be noted that large sections in the mid to north western section of the licence, namely the Old Airfield, Speaks and the Mine Club have been sterilised by industrial buildings and the construction of private residences.