Reserves — Mineable Quantities. As part of the “2005 Basic Design Report” by ENFI an estimate of Mineable Quantities was carried out based on mine designs applied to the ENFI 2005 Datamine model. The resource is planned to be extracted using sub level open stopping with backfilling of voids where required. The currently designed mine plans will deplete the resource by 9.9Mt at 10.03% Zn and 3.29% Pb. The average ore loss is 14.76% and dilution 7.66%. Due to lack of reporting of the original resource/reserves into either Chinese or JORC code classification and a lack of digital mine design, M-MC could not report the reserves in compliance with the recommendations of the JORC code. For this reason M-MC has used Mineable Quantities when referring to the reserves as shown in Table 5.7.
Reserves — Mineable Quantities. Ore Reserves have not been reported by category, and do not include parameters to reflect mining loss and dilution. The estimates of “ore reserves” have therefore been referred to as “Mineable Quantities”. M-MC has estimated the Mineable Quantities remaining as at December 2008 based on information contained within the 1991 Basic Design Report and recent site surveys and production information for the South Orebody only. The South Orebody open cut design is based on various optimisations carried out by ENFI in 1991 using USD2,680/t Cu and USD12,868/kg Au prices. This work indentified the 626mRL as the base of economic extraction by open cut with an overall slope angle of 45o above the 758mRL and 42o below. The reserves were reported within this pit shell with no dilution or ore loss factor applied and a variable Cu cut-off grade, based on depth, between 0.275% and 0.25% Cu. A summary of M-MC’s estimated Mineable Quantities remaining as at December 2008 for the South Orebody is shown in Table 6.9. M-MC reported these quantities as “Mineable Quantities” without application of recoveries or dilution, as quoted in the 1991 Basic Design Report. 854-626 mRL. . . . . . . . . . . . . . . . Open cut 0.25% 49.7 2.68 0.45 0.47 Mining as at December 2008 had reached parts of the 842mRL. These estimates do not include mining loss or dilution. We use the geological reserves standard published by the PRC Government in reporting the Mineable Quantities for the Saindak copper-gold mine. Whilst no JORC compliant reserves have been estimated, the likely result would be of a similar order of magnitude to the current estimates of Mineable Quantities. Silver grades in the order of 2.2-2.6g/t are also expected to be recovered during mining, based on previous production. These however cannot be reported under Mineable Quantities due to lack of supporting drill information.
