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November 15, 2012                                               

Excelsior Mining Corp. (TSX-V: MIN) (Frankfurt: 3XS) (OTCQX: EXMGF) (“Excelsior” or “the Company”) announces recovery results for recent metallurgical test work performed on core samples from its Gunnison Copper project in Cochise County, Arizona. The tests were completed at the laboratories of independent consultant, METCON Research, of Tucson, Arizona, under the direction of Dr. Ronald J. Roman, P.E. 

Six leach box tests were completed on whole HQ core (~63.5mm diameter), representing a range of rock types and varying from low permeability (low fracture intensity) to high permeability (high fracture intensity). As expected, the samples with the higher fracture intensity (permeability) gave the higher copper extractions, averaging approximately 51% total copper extraction. 

“We are very pleased with the results from these metallurgical tests,” stated Stephen Twyerould, President and CEO. “They are in line with our PEA and continue to support our view that this project will one day make a significant ISR copper producer.” 

The results of these six leach box tests are summarized in the following table:

Sample # Rock Type Permeability


(Total Cu%)




% Total Cu

2 Upper Abrigo Low 0.65 45 32
5 Upper Abrigo High 0.55 45 49
3 Lower Abrigo Moderate 0.55 45 28
4 Middle Abrigo High 0.36 45 52
7 Martin Low 0.80 45 19
8 Martin High 1.93 82 54

*Calculated head grade


When factored for the effects of the test procedure, average acid consumption numbers are in line with the Preliminary Economic Assessment (PEA)(see news release dated December 1, 2011 for additional details). A further 17 metallurgical tests are currently underway; designed to explore the relative effects of leach solution acid strength and irrigation flow rate on copper extraction and acid consumption; results are expected before the end of the year. 

The metallurgical test program is being conducted at METCON Research under the supervision of Dr. Ronald J. Roman, P.E., of Leach, Inc., Tucson, Arizona, an independent consultant who is a Qualified Person (QP) as defined by NI43-101. Dr. Roman has reviewed and approved the technical information disclosed above in this news release. The QP verified the underlying test data through his supervision of the program. 

 Project Summary 

The Gunnison Copper Project is located in a remote section of Cochise County in southeastern Arizona. The focus of the project is the North Star deposit, which currently has a total Indicated mineral resource of 3.21 billion pounds of oxide copper (511 M tons at 0.31%) and an Inferred mineral resource of 0.88 billion pounds of oxide copper (159 M tons at 0.28%). This oxide mineral resource has the potential to be mined using in-situ recovery methods. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

 About Excelsior 

Excelsior is an exploration company with a copper project located within the Copper Porphyry Belt of Arizona. The Gunnison Copper Project is located close to the required infrastructure and its oxide resource has the potential to be mined using in-situ recovery methods. The Excelsior team consists of experienced professionals with proven track records of advancing projects towards production. 

Excelsior’s exploration work on the Gunnison Property is supervised by Dr. Stephen Twyerould, Fellow of AUSIMM, President and CEO of Excelsior, and a Qualified Person as defined by NI 43-101. Dr. Twyerould has reviewed and approved the technical information disclosed in the “Project Summary” and “About Excelsior” sections of this news release.

Further details about Excelsior can be found at:  http://www.excelsiormining.com. Further information about the Gunnison Copper Project can be found in the technical report filed on SEDAR at www.sedar.com entitled: “Gunnison Copper Project Preliminary Economic Assessment, NI 43-101 Technical Report” dated November 18, 2011. 


 "Stephen Twyerould"

President & CEO

 For further information regarding this press release, please contact: 

Excelsior Mining Corp.
Concord Place, Suite 300, 2999 North 44th Street, Phoenix, AZ, 85018. 

JJ Jennex, Vice President, Corporate Affairs
T: 604-681-8030 x240
E: This email address is being protected from spambots. You need JavaScript enabled to view it.

Cautionary Note Regarding Forward-Looking Information

This news release contains "forward-looking information" concerning anticipated developments and events that may occur in the future. Forward looking information contained in this news release includes, but is not limited to, statements with respect to: (i) the estimation of inferred and indicated mineral resources; (ii) success of exploration activities; (iii) production from the Gunnison Project; (iv) overestimation of acid consumption; (v) copper recovery rates and (vi) the ability to mine Gunnison using in-situ recovery mining techniques are forward-looking statements.

In certain cases, forward-looking information 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", "might" or "will be taken", "occur" or "be achieved" suggesting future outcomes, or other expectations, beliefs, plans, objectives, assumptions, intentions or statements about future events or performance. Forward-looking information contained in this news release is based on certain factors and assumptions regarding, among other things, the estimation of mineral resources, the realization of resource estimates, copper and other metal prices, the timing and amount of future exploration and development expenditures, the estimation of initial and sustaining capital requirements, the estimation of labour and operating costs, the availability of necessary financing and materials to continue to explore and develop the Gunnison Project in the short and long-term, the progress of exploration and development activities, the receipt of necessary regulatory approvals, the completion of the environmental assessment process, the estimation of insurance coverage, and assumptions with respect to currency fluctuations, environmental risks, title disputes or claims, and other similar matters. While the Company considers these assumptions to be reasonable based on information currently available to it, they may prove to be incorrect.

Forward looking information involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by the forward-looking information. Such factors include risks inherent in the exploration and development of mineral deposits, including risks relating to changes in project parameters as plans continue to be redefined including the possibility that mining operations may not commence at the Gunnison Project, risks relating to variations in mineral resources, grade or recovery rates resulting from current exploration and development activities, risks relating to the ability to access infrastructure, risks relating to changes in copper and other commodity prices and the worldwide demand for and supply of copper and related products, risks related to increased competition in the market for copper and related products and in the mining industry generally, risks related to current global financial conditions, uncertainties inherent in the estimation of mineral resources, access and supply risks, reliance on key personnel, operational risks inherent in the conduct of mining activities, including the risk of accidents, labour disputes, increases in capital and operating costs and the risk of delays or increased costs that might be encountered during the development process, regulatory risks, including risks relating to the acquisition of the necessary licenses and permits, financing, capitalization and liquidity risks, including the risk that the financing necessary to fund the exploration and development activities at the Gunnison Project may not be available on satisfactory terms, or at all, risks related to disputes concerning property titles and interest, environmental risks and the additional risks identified in the “Risk Factors” section of the Company’s Annual Information Form for the most recently completed financial year or other reports and filings with applicable Canadian securities regulations.

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 information, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. Accordingly, readers should not place undue reliance on forward-looking information. The forward-looking information is made as of the date of this news release.. Except as required by applicable securities laws, the Company does not undertake any obligation to publicly update or revise any forward-looking information.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release, and no securities regulatory authority has either approved or disapproved of the contents of this release.










What is
In-Situ Mining