TORONTO, CANADA -- (Marketwire) -- 01/21/13 -- Note: all amounts in this press release are shown in US dollars unless otherwise noted.
Inmet Mining Corporation (Inmet) (TSX: IMN) is pleased to announce the addition of an inferred copper mineral resource at its wholly-owned Cobre Las Cruces property in southern Spain. At a 1.0% copper equivalent cut-off, the total additional inferred mineral resource is estimated to be 38 million tonnes at a copper equivalent grade of 2.76% containing an estimated 1.1 million tonnes on a copper equivalent basis, being 0.4 million tonnes of copper, 1.0 million tonnes of zinc, 0.5 million tonnes of lead and 33 million ounces of silver.
Scott Herr, Inmet's Vice President, Mining commented, "With the Las Cruces cathode operation now running at design capacity, it is time to turn our attention to the next phase of mining. We look forward to completing our scoping study of the primary sulphides deposit and evaluating the economics of different processing options. Our studies will target a throughput range of 2.5 to 4 million tonnes per year. If those studies demonstrate economic viability at such rates, this would translate into an expected additional 10 to 15 years of mine life."
The sensitivity of the inferred mineral resource at a variety of copper equivalent cutoff grades is presented in Table 1 below. The resource is made up of a zone of primary sulphides located below and adjacent to the high grade secondary chalcocite reserves that are presently being mined and processed by atmospheric leaching. The secondary chalcocite reserves are not presented in the two tables below, which address only the two mineral resource bodies that have been estimated for future phases of mine life. The secondary ore body itself lies underneath the previously reported gossan resource, as depicted in Figure 1 below. The gossan resource, which is rich in lead and precious metals, is presented in table 2. The position and relative configuration of the three distinct types of mineral resources is illustrated in Figure 1 below.
Table 1: Inferred Resource(1)- Primary Sulphides Cobre Las Cruces---------------------------------------------------------------------------- Quantity Grade Contained Metal --------------------------------------------------------------------Cut-off Million CuEq Cu Zn Pb Ag CuEq Cu Zn Pb Ag(CuEq%) tonnes %(2) % % % g/t Kt Kt Kt Kt Moz----------------------------------------------------------------------------0.5 44.9 2.47 0.97 2.28 1.13 24.0 1,106 433 1,024 509 34.7----------------------------------------------------------------------------1.0 38.2 2.76 1.05 2.61 1.29 27.2 1,055 401 999 495 33.4----------------------------------------------------------------------------1.5 32.3 3.04 1.11 2.95 1.47 30.5 981 358 951 474 31.6----------------------------------------------------------------------------2.0 26.8 3.30 1.16 3.26 1.64 33.5 886 312 874 441 28.9----------------------------------------------------------------------------2.5 20.5 3.63 1.26 3.59 1.84 37.0 745 258 737 378 24.4---------------------------------------------------------------------------- (1) Mineral resources are not mineral reserves and do not have demonstrated economic viability. (2) Copper equivalent grade is calculated using $2.75/lb Cu, $1.00/lb Zn, $1.00/lb Pb and $20/oz Ag and is not adjusted for metallurgical recoveries as these remain uncertain. The formula used is as follows: Cu Eq = Cu% + (Zn% x 0.364) + (Pb% x 0.364) + (Ag g/t x 0.0106). The base case cut-off grade of 1.0% CuEq, highlighted in the table, assumes potential underground extraction method with total site operating cost of approximately $50/tonne.Table 2: Indicated and Inferred Mineral Resource(1)- Gossan Sulphides CobreLas Cruces---------------------------------------------------------------------------- Quantity(2) Grade Contained Metal ------------------------------------------------- Thousand Au Ag Pb Au Ag PbClassification tonnes g/t g/t % Koz Koz Kt----------------------------------------------------------------------------Indicated mineral resourceGossan stockpile 958 3.85 109 5.81 119 3,356 56----------------------------------------------------------------------------Total indicated 958 3.85 109 5.81 119 3,356 56----------------------------------------------------------------------------Inferred mineral resourceGossan 1,834 2.32 40 1.88 137 2,383 35----------------------------------------------------------------------------Total inferred 1,834 2.32 40 1.88 137 2,383 35---------------------------------------------------------------------------- (1) Mineral resources are not mineral reserves and do not have demonstrated economic viability. (2) All figures are rounded to reflect the relative accuracy of the estimates. Gossan resource is reported at a cut off of 1 gpt gold. The gossan inferred mineral resource exists within the limits of the secondary sulphides reserve pit design and will be mined, placed in stockpile on surface and, when stockpiled, will be reclassified as indicated mineral resource.
