African Copper Plc
TSX : ACU
AIM : ACU

African Copper Plc

April 03, 2006 01:00 ET

African Copper Plc: 2005 Drilling Programme Triples Contained Copper at Mapanipani North

LONDON, UNITED KINGDOM--(CCNMatthews - April 3, 2006) - African Copper ("African Copper" or the "Company") (TSX:ACU)(AIM:ACU)(BSE:African Copper) is pleased to release the technical report from its independent consultants A.C.A Howe International Limited ("Howe") which covers the work carried out in 2005/6 including the drilling and resource estimates at Mapanipani North.

  • A 38,000 metre resource definition drill programme has tested a two kilometre strike extent at Dukwe. The mineralization extends for at least 4,370 metres along the Dukwe trend.
  • Estimates of the contained copper in the northern 600 metres ("Mapanipani North") have increased to approximately 600 million pounds of copper (39.2 million tonnes at 0.71% Cu classified as indicated resources at 0% cut-off). Estimates for the remaining 1,400 metres of drilled strike extent are being prepared.
  • Based on a bulk mining scenario the indicated sulphide copper resource at Mapanipani North is estimated to contain about 315 million pounds at a 0.75% Cu cut-off (indicated resources of 14.4 million tonnes at 1.01% Cu) between 150 metres and 550 metres below surface.
  • A selective mining scenario examined the possibility of extracting only the higher grade zones within the bulk estimate and resulted in the resource grade increasing to in excess of 2% Cu (indicated resources of 300,000 tonnes at 3.4% Cu and inferred resources of 3,400,000 tonnes at 2.09% Cu at a 1.5% Cu cut off).
  • Howe recommends an underground exploration programme be conducted to provide the detailed information necessary to convert the sulphide resources into reserves which could ultimately be included in a mining plan. This programme is expected to cost approximately US$ 32 million over a 2 to 3 year period.
  • African Copper plans to commence construction of the underground access in Q3 of this year subject to arranging appropriate financing and awarding excavation contracts.
The Dukwe Deposit in north eastern Botswana is a structurally controlled hydrothermal copper deposit that contains near surface copper deposits of oxide, supergene and transition material with a substantial resource of underlying sulphide mineralization. Throughout 2005 and early 2006 the Company completed an intensive delineation drilling program on the underlying sulphide mineralization. Drilling is expected to be completed shortly with the final resource estimates for the entire 2,000 metres of tested strike extent expected to be completed by 30 June 2006. The 38,000 metre drill programme at Dukwe, and the resource estimation, were managed and supervised by RSG Global Pty Ltd. ("RSG") an independent geoscience consulting company based in Perth Australia. The resource estimation has been summarized in the independent report prepared by Howe dated March 30, 2006 entitled "Technical Report on the Dukwe Copper Project and the Matsitama Prospecting Licences Botswana, Africa" (the "Technical Report") that can be found on SEDAR at www.sedar.com and the Company's website at www.africancopper.com. The northern 600 metres of the 2,000 metres extent of known mineralization has been drilled at nominal 60 metre line spacing with 120 metre vertical pierce points. The current resource estimate extends from 170 metres below surface to a depth of about 550 metres and excludes the surface oxide, supergene and transition resource. The broad breccia package which hosts the copper mineralization extends beyond these depths. The mineralization remains open to the north, south and to depth. The mineralization at the Dukwe deposit is a structurally controlled hydrothermal semi-massive to disseminated copper deposit contained within a quartz-calcite breccia that has experienced at least 4 phases of deformation. The shear zone and breccia are near vertical and are up to 60 metres wide. Mineralization is discontinuous, and seems to be controlled by an early tensional event with copper emplacement into tension gashes that were oblique to the main shear direction. Subsequent deformation appears to have dragged these tension gashes into parallelism such that the contacts of the individual copper-bearing lenses may still be discrete within the shear but are now almost parallel to the shear contacts. Late stage brittle faulting has displaced some of the lenses to the north-east. The coarse grained, semi-massive nature of the structurally controlled sulphide mineralization results in a "nugget effect" that requires either closer spaced drilling or an underground exploration program to move the sulphide copper into a mineral reserve category. African Copper is examining two underground extraction scenarios for the sulphide mineralization: 1) selective extraction of the higher grade copper sulphide bearing lenses; and 2) bulk mining of the entire sulphide breccia zone. Selective Mining - Mapanipani North (Sulphides) RSG prepared a resource estimate which examined the resources available to a selective mining operation. The mineralized shear-hosted breccia package at Mapanipani North was subdivided into 15 discrete areas and each was estimated and considered individually. Samples were composited into 1m lengths which were then fit to 2.5m by 15m by 15m blocks for estimating purposes. The 15 mineralized zones were confined by geological and structural observations The geostatistical variations introduced by these small composite lengths and block sizes results in a lower confidence level in the overall continuity of grades within the discrete areas. This confidence level is reflected in the classification of most resources under the selective mining scenario as inferred resources. The grades and tonnages shown in the table below are totals for all 15 lenses. Each lens was estimated individually and each carries its own tonnage and grade at a cut-off level. Grades shown are averages and tonnages are totals. Total mineralization within each lens is therefore classified as inferred resources. The individual lenses are of various sizes and at a 0.03 % cut-off range from 300,000 tonnes with 0.34% Cu to 9.1 million tonnes at 1.10% Cu. At a 2% cut-off, the lenses show a range from 100,000 tonnes to 1.3 million tonnes and grades range from 2.35% to 4.63% Cu. The grade/tonnage relationships shown below have not been optimized, nor has any attempt been made to discard lower grade material from the estimate. This optimization work will be completed over the next three months in conjunction with the complete resource calculations for the entire Dukwe Deposit.

2006 RSG Resource Estimates for Selective Underground Mining at 
Mapanipani North Sulphide Deposit

            Indicated Resource                 Inferred Resource
       --------------------------------------------------------------
Cut-             Grade   Contained                 Grade   Contained
Off     Tonnes      Cu    Cu Metal       Tonnes       Cu    Cu Metal
(%)     (t'000)     (%)         (t)      (t'000)      (%)         (t)
---------------------------------------------------------------------
0.03     1,500    1.23      18,450       21,700     0.81     175,770
0.25     1,200    1.45      17,400       19,000     0.89     169,100
0.50     1,000    1.68      16,800       14,900     1.10     163,900
0.75       700    2.32      16,240       11,400     1.32     150,480
1.00       600    2.61      15,660        7,900     1.53     120,870
1.25       400    2.96      11,840        4,900     1.84      90,160
1.50       300    3.40      10,200        3,400     2.09      71,060
1.75       300    3.95      11,850        2,300     2.32      53,360
2.00       200    4.37       8,740        1,600     2.58      41,280
Mineral resources that are not mineral reserves do not have demonstrated economic viability. Bulk Mining - Mapanipani North (Sulphides) RSG also prepared a resource estimate which examined the resources available to a bulk mining operation. The entire width of the mineralized shear-hosted breccia package of up to 60 metres was considered. Samples were composited into 5m lengths which were then fitted to 10m x 30m x 30m blocks for estimating purposes. This procedure has the effect of reducing the impact of narrow high grade intersections in the final estimate. Heavy Liquid separation tests using a media with a specific gravity of 2.96 returned encouraging results (as reported in a Press Release dated 21 February, 2006). The coarse grained nature of Dukwe mineralization results in very few fines produced during crushing and little copper is lost to slimes in this process. The gangue minerals are essentially quartz, carbonate and minor graphite which are readily separated from the copper bearing minerals chalcopyrite and chalcocite. Preliminary testing on a crush size of 90% passing -1.7mm resulted in about a 84% recovery of copper to the heavies with a 7.5% mass pull from a sample of sulphide material that graded 1.47% copper. This result has positive implications for bulk mining of the deeper sulphide zones since a Dense Media Separation (DMS) plant between the crusher and mill may provide a quick, inexpensive pre-concentration step. Bulk mining of the sulphide zones may result in lower mining costs, lower development capital and a reduced mining risk.

2006 RSG Resource Estimates for Bulk Underground Mining at Mapanipani
North Sulphide Deposit

            Indicated Resource                 Inferred Resource
       --------------------------------------------------------------
Cut-             Grade   Contained                 Grade   Contained
Off     Tonnes      Cu    Cu Metal       Tonnes       Cu    Cu Metal
(%)     (t'000)     (%)         (t)      (t'000)      (%)         (t)
---------------------------------------------------------------------
0.00    39,200    0.71     278,320       19,000     0.61     115,900
0.25    38,500    0.72     277,200       18,800     0.62     116,560
0.50    31,400    0.80     251,200       12,500     0.74      92,500
0.75    14,400    1.01     145,440        4,300     0.92      39,560
1.00     5,900    1.28      75,520        1,100     1.07      11,770
1.25     2,500    1.56      39,000          100     1.33       1,330
1.50     1,000    1.88      18,800
1.75       400    2.19       8,760
2.00       200    2.40       4,800
RSG has classified the bulk of these resources as Indicated, reflecting their confidence in the continuity of lower grade copper mineralization over broad widths at lower grades. The background grade of the breccia zone appears to be about 0.70% copper. Mineral resources that are not mineral reserves do not have demonstrated economic viability. Further infill drilling is required to improve the confidence in both of these estimates and aid in the delineation of areas to be mined. Howe recommends that this programme is more effectively completed by an underground drill programme that includes development into the respective mineralized zones. The objective of this programme would be to increase the confidence level of the resources, as well as an increase in the grades of the discrete mineralized zones. The number, shape, tonnage and grades of various lenses that will be included in an eventual mine plan for these deeper sulphides will be defined during this underground exploration program. The underground exploration plan for Dukwe Project has been estimated by Howe to cost about $32.3 million. This programme is designed to enable the Company to complete a decline access to a sufficient depth that drilling and crosscutting into the sulphide zones can be completed. This programme is designed to allow the conversion of resources into reserves and may ultimately be included in a mining plan. African Copper intends to commence construction of the underground access in Q3 of this year subject to arranging appropriate financing and awarding excavation contracts. The Technical Report is compliant with National Instrument 43-101. Unless otherwise indicated, technical information contained in this release is based on information compiled by Howe. Messrs. F. Lee, H. Coates, M. Newbury, and D. Titaro, who are employees of, or consultants to Howe and are independent of African Copper are the qualified persons (as defined in National Instrument 43-101) overseeing preparation of the Howe report and are responsible for the technical information contained therein . This press release has been prepared under F. Lee's supervision. African Copper is a tri-listed (AIM, TSX, Botswana Stock Exchange) international exploration company. In addition to the Dukwe Project the Company's other interests are the 4,000 sq km Matsitama exploration concession adjacent to Dukwe, which contains two known copper deposits and numerous base metal exploration targets. African Copper has approximately 52 million shares outstanding. This document may contain "forward looking statements". Forward looking statements include, but are not limited to, statements with respect to the future price of copper, the estimation of mineral reserves and resources, timing of the development of the Company's projects, budgets, capital and operating cost estimates and forecasts, results of mining operations, mining extraction and recovery rates, the conversion of mineral resources to mineral reserves, estimations of mine life, success of exploration activities, permitting time lines, requirements for additional capital, government regulation of mining operations, environmental risks, unanticipated reclamation expenses, title disputes or claims and the timing and possible outcome of pending and future regulatory applications. In certain cases, forward looking statements can be identified by the use of words such as "plans", "expects" or "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or variations of such words and phrases or state that certain actions, events or results "may", "could", "would", "should", "might" or "will be taken", "occur" or "be achieved" and include the negative variation of such phrases. Forward looking statements involve known and unknown risks, uncertainties and other factors that may cause the actual results, performance or achievements of the Company or the Company's projects, or any of them, to be materially different from any future results, performance or achievements expressed or implied by the forward looking statements. Such factors include, among others, risks related to conclusions of economic evaluations; changes in project parameters as plans continue to be refined; future prices of copper; unexpected increases in capital or operating costs; possible variations in mineral resources or reserves, grade or recovery rates; failure of equipment or processes to operate as anticipated; accidents, labour disputes and other risks of the mining industry; delays in obtaining governmental consents, permits, licences and registrations or financing or in the completion of development or construction activities. Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward looking statements, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. There can be no assurance that forward looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward looking statements. For further information about please visit.www.sedar.com or our website at www.africancopper.com. The Toronto Stock Exchange does not accept responsibility for the adequacy or accuracy of this release.

Contact Information

  • African Copper Plc
    David Jones / Joseph Hamilton
    +44 (0) 20 7321 3721
    or
    Numis Securities Limited (NOMAD)
    John Harrison / Nick Westlake
    +44 (0) 20 7776 1590
    or
    Parkgreen Communications
    Justine Howarth / Ana Ribeiro
    +44 (0) 20 7493 3713