VANCOUVER, May 20, 2011 /PRNewswire/ -- African Metals Corporation ("AFR") is pleased to report that the Company has successfully completed trial processing of a bulk sample of the historic Luisha South stockpile. Approximately 200 tonnes of bulk sample grading approximately 2% copper and 0.3% cobalt has been excavated and trucked to a generator powered, modular concentration plant including a DMS (Dense Media Separator) plant and gravity spirals.
The 200 tonne material produced a DMS concentrate grading approximately 32% copper, 1.2% cobalt; fines concentrate from spirals graded approximately 28% copper and 1.6% cobalt. The results highlight the economic potential of processing the stockpile material using gravity based separation process technology.
The bulk processing results will be used in conjunction with metallurgical test results from METS-SGS in Perth, and a maiden resource estimation which is expected in May, to produce a feasibility study and cash flow model.
AFR aims to commence full time concentrate production by end Q3 2011, if the study and cash flow modeling produce favorable scenarios.
Luisha South Project Stockpile RC Drilling
In October 2010, Magnum Drilling Sprl completed a 42 hole, Reverse Circulation (RC) drilling program on top of the Luisha South stockpile. Based on the positive assay results from the RC drilling program, and the observation that the mineralization is of an oxide nature (malachite and heterogenite), AFR has engaged METS and SGS in Perth, Australia, to conduct metallurgical beneficiation test work aimed at producing a higher grade concentrate amenable to conventional hydrometallurgical leaching. Test work on ore characteristics and heavy media separation qualities has commenced, with beneficiation results expected late May.
With the goal of commencing production of an oxide concentrate by the end of Q3, 2011, AFR took an opportunity to run a bulk ore sample through a nearby DMS Plant and spirals. The results of the bulk sample test run were to be used in conjunction with the metallurgical beneficiation test work to optimize copper and cobalt recovery.
An initial composite sample was selected to be processed through the DMS plant. The composite sample represented coarse Reverse Circulation (RC) drill chips collected from the stockpile drilling in 2010; the chips came from holes drilled across the stockpile.
Approximately 300kg of composite drill material grading on average 0.3% copper and 0.3% cobalt, was transported some 40km to a generator powered, modular DMS (Dense Media Separator) plant and spirals near Likasi for processing.
The DMS plant usually operated at an average through put of 50 tonnes of ore per hour, with the spirals processing fines at a throughput rate of 60 tonnes of ore per hour. The plant was simple, and consisted of a Primary Crushing Circuit (-150mm static grizzly screen, jaw crusher, conveyor system, scrubber, -1.6mm double deck sizing screen); Spiral Plant (processing -1.6mm fines); and DMS Plant (processing -27mm to +1.6mm material). The spiral bank and conveyor system are shown in Photo 1 here: http://files.newswire.ca/138/AFRphotos.pdf.
Approximately four x 1kg samples were collected from four stages during the DMS plant test run. The samples were dispatched to SGS laboratories in Kalulushi, Zambia, where they were analyzed for copper and cobalt. The results are listed in Table 1.
Weight Cu Co Cu Co Sample (Kg) Comment % % Acid_sol_% acid_sol_% BIN - pre DMS, P002458 1.12 composite average 0.3 0.3 0.3 0.2 SPIRAL - fines P002459 0.62 reject 1.6 0.1 1.4 0.1 SPIRAL - fines P002460 1.22 concentrate 4.7 0.2 4.5 0.2 P002461 1.02 DMS concentrate 15.1 0.5 14.8 0.3 Table 1: Luisha Stockpile RC - 300kg composite bulk sample for DMS test work
The DMS plant produced a concentrate grading 15.1% Cu, 0.5% Co.
The Spirals concentrate of fine grained material produced a concentrate grading 4.7% Cu, 0.2% Co. The results indicated that the DMS plant successfully produced a higher grade concentrate.
The DMS process plant operations' team however considered the performance of the DMS plant during the processing of the 300kg composite drill material to have been below par; the plant and spirals struggled with the fine-grained nature of the composite RC hammer sample, and the plant may have introduced contamination issues. As a result the company decided to run another trial by processing a 200 tonne bulk tonnage stockpile sample.
Approximately 200 tonnes of stockpile material grading on average 2% copper and 0.2% cobalt, was excavated from the northern portion of the stockpile. The stockpile sampling location is highlighted on Figures 1 and 2 here: http://files.newswire.ca/138/AFRfigure1&2.pdf.
Twenty-two truckloads of sample material was removed from the stockpile and transported to the DMS plant for processing. The bulk tonnage sample was successfully processed producing a high grade concentrate (Photo 2: http://files.newswire.ca/138/AFRphotos.pdf).
A total of 28 x 1kg (approximately) grab samples were collected from various stages of the processing of the bulk sample; 22 samples originated from the trucks hauling the samples whilst six were sourced from the DMS plant during operations. All samples were dispatched to SGS laboratories in Kalulushi, Zambia, for analysis. Results of the analysis summarized in Table 2.
Weight Cu Co Cu Co Sample (Kg) Comment % % Acid_sol_% acid_sol_% P002484 1.03 DMS concentrate 32.63 1.15 31.52 0.6 P002485 1.04 Oversize DMS reject 1.58 0.24 1.57 0.21 P002486 1.08 SPIRAL - fines reject 4.87 0.83 4.54 0.65 BIN - pre DMS, P002487 1.10 composite average 3.37 0.48 3.18 0.39 P002488 1.06 SPIRAL - fines concentrate 28.74 1.61 24.6 1.1 P002489 1.18 Undersize DMS reject 0.49 0.03 0.44 0.03 Table 2: Luisha Stockpile RC - 200 Tonne bulk sample for DMS Trial
The 200 tonne material produced a DMS concentrate grading approximately 32% copper, 1.2% cobalt; fines concentrate from spirals graded approximately 28% copper and 1.6% cobalt.
Results from the truck loads samples are summarized in Table 3. The samples averaged approximately 4% copper and 0.6% cobalt.
Weight Cu Co Cu Co Sample (Kg) Comment % % Acid_sol_% acid_sol_% P002462 1.11 Truck Grab 2.86 0.34 2.84 0.24 P002463 1.10 Truck Grab 2.82 0.66 2.8 0.49 P002464 1.05 Truck Grab 3.89 0.66 3.84 0.49 P002465 1.08 Truck Grab 3.02 0.46 2.94 0.34 P002466 1.10 Truck Grab 2.12 0.36 1.84 0.22 P002467 1.07 Truck Grab 0.64 0.38 6.09 0.25 P002468 1.17 Truck Grab 16.78 1.35 16.12 0.89 P002469 1.04 Truck Grab 2.88 0.64 2.74 0.47 P002470 1.18 Truck Grab 4.76 0.56 4.52 0.38 P002471 1.08 Truck Grab 3 0.39 2.93 0.27 P002472 1.08 Truck Grab 3.67 0.85 3.54 0.56 P002473 1.18 Truck Grab 4.26 0.94 4.19 0.65 P002474 1.02 Truck Grab 4.85 0.83 4.83 0.6 P002475 1.14 Truck Grab 3.15 0.35 2.97 0.22 P002476 1.12 Truck Grab 2.55 0.41 2.29 0.28 P002477 1.17 Truck Grab 5.99 0.81 5.76 0.56 P002478 1.12 Truck Grab 3.57 0.54 3.43 0.37 P002479 1.04 Truck Grab 4.34 0.55 4.26 0.41 P002480 1.03 Truck Grab 3.06 0.56 3.06 0.37 P002481 1.10 Truck Grab 3.12 0.39 2.93 0.27 P002482 1.06 Truck Grab 3.5 0.52 3.41 0.36 P002483 1.05 Truck Grab 2.73 0.39 2.55 0.31 Average 3.98 0.59 4.09 0.41 Table 3: Luisha Stockpile RC - 200 Tonne bulk sample for DMS trial; grab sample analysis from 22 truckloads transporting sample to DMS plant.
The results of the bulk tonnage trial highlight the economic potential of processing the stockpile material using DMS plant and spiral technology.
AFR intends to estimate a copper and cobalt resource of the stockpile based on the results of the RC drilling. The resource estimation is in progress, and is expected to be issued during May.
AFR will report the metallurgical test results and resource estimation of the stockpile as they become available.
Nigel Ferguson, AusIMM, President and CEO of the Company and a qualified person under National Instrument 43-101, has verified data disclosed in this release.
ON BEHALF OF THE BOARD OF DIRECTORS OF AFRICAN METALS CORPORATION
President & CEO
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This News Release contains forward-looking statements. Forward-looking statements are statements which relate to future events. These statements are only predictions and involve known and unknown risks, uncertainties and other factors that may cause our or our industry's actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. While these forward-looking statements, and any assumptions upon which they are based, are made in good faith and reflect our current judgment regarding the direction of our industry, actual results will almost always vary, sometimes materially, from any estimates, predictions, projections, assumptions or other future performance suggested herein. Except as required by applicable law, the Company does not intend to update any of the forward-looking statements to conform these statements to actual results.
About African Metals Corporation.
African Metals Corporation [TSXV "AFR"] is a Canadian listed company focused on the discovery and development of Copper and Cobalt deposits in the highly mineralized Katanga Copper Belt of the world renowned Africa Copper Belt in the Democratic Republic of Congo ("DRC").
AFR purchased all the assets of Chevalier Resources Inc. in March 2010 including a 57% interest in the Luisha South Project contained within licence PEPM 4881, Katanga Provence, Democratic Republic of the Congo ("DRC") through subsidiaries incorporated in the DRC. In July AFR negotiated a further 18% interest in the project with the option to increase the equity interest to 90% based on results. The project is located 75 kilometres northwest of Lubumbashi, the capital of Katanga Province and consists of approximately 16.2kmsquared.
The Luisha South Project includes a small historical open pit mine and associated stockpile and is underlain by Roan Group sediments which host major Cu-Co deposits in the DRC. The Luisha South ore body was explored between 1923 and 1928 and an oxide deposit with an estimated pre-production tonnage of approximately 350,000 tonnes at 8.6% Cu was delineated. The Luisha Project also covers some three kilometres of the Roan Group strike length which is favorable for Cu-Co mineralization. AFR is currently conducting metallurgical tests on stockpile Reverse Circulation drill samples to determine characteristics and heavy media separation qualities, with the aim of commencing production of an oxide concentrate by the end of Q3 2011.
For further information:
Jag Sandhu, Corporate Development, +1-604-306-1950
SOURCE African Metals Corporation