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.
Inmet's subsidiary, Cobre Las Cruces, with the assistance of its technical consultants, is studying the opportunity to recover and process both the gossan and primary sulphides resources through various combinations that include the expansion of the current open pit and/or underground mining. Processing options include possible modification of the existing atmospheric leach plant, toll processing at a third party facility or the development of a stand-alone flotation plant to treat both the gossan and the primary sulphides mineralization. Cobre Las Cruces intends to complete a scoping study in 2013 to evaluate the economic basis for moving into a feasibility study stage.