Nov 3 2010
Excelsior Mining Corp. (TSX VENTURE:MIN) has announced additional details on the Gunnison Copper Property.
Excelsior has the option to acquire 100% ownership of the Gunnison Property located within the copper porphyry belt in southern Arizona. Gunnison contains an NI 43-101 inferred resource of 4.77 billion pounds of copper which remains open for expansion (See News Release dated June 16, 2010).
Gunnison is located approximately 65 miles southeast of Tucson and 1.5 miles southeast of the historic Johnson Camp mining district. The Property is located near the I-10 freeway and covers approximately 6.085 acres (2,461 hectares). The area is sparsely populated, but sufficient skilled labour for the project is located nearby in the towns of Benson, Wilcox and Tucson. The area has well developed infrastructure for mining with the solvent extraction electrowinning (SX-EW) plant located at the Johnson Camp mine nearby. Railway and electrical power are also accessible on the property.
The Gunnison Property is composed of two deposits, the North Star and South Star Deposits. The North Star Deposit is the most advanced and is over 2,500 meters (m) long, 700m wide and 200m thick and remains open for further expansion. It contains over 90% of the total inferred resource of 4.77 billion pounds of copper.
Over two-thirds of the copper occurs as oxide copper, which has the potential to be mined using in-situ recovery (ISR) methods. ISR is a low cost and environmentally-friendly process of extracting metals from deposits. Copper has successfully been extracted using ISR in Arizona on numerous occasions including the San Manuel Mine located less than 70 miles to the northwest of Gunnison.
Another emerging ISR copper project in Arizona is the Florence Project ("Florence"), located approximately 100 miles from Gunnison. Florence is being developed by Curis Resources Ltd. ("Curis"), a Hunter Dickenson Inc Company. A positive Preliminary Economic Assessment for Florence was recently completed which indicated initial capital costs of approximately US$240 million, operating costs of US$0.68 per pound of copper, and an after tax NPV of US$550 million using US$3.00 per pound copper, discount rate of 7.5% and production of about 77 million pounds of copper per year for 19 years. Curis are aiming for initial copper production beginning in the third quarter of 2012. Mineral resources that are not mineral reserves do not have demonstrated economic viability.
Given that Gunnison is similar in tonnage and grade to Florence and that preliminary tests suggest it is amenable to ISR and SX-EW copper production, Excelsior expects that its own investigations on Gunnison may produce similar results to Florence. Further details regarding the upcoming programs will be released shortly.
Stephen Twyerould, (Fellow of AUSIMM), President and CEO of Excelsior and a Qualified Person as defined by National Instrument 43-101, has reviewed and is responsible for the technical information contained in this news release.
Source: Excelsior Mining Corp.