Toronto, September 24, 2012 – Scorpio Mining Corporation (TSX:SPM) (“Scorpio Mining” or the “Company”) today announced an independent updated Mineral Resources estimate for its 100% owned El Cajón Development Project in Sinaloa State, Mexico completed by Mine Development Associates of Reno, Nevada (“MDA”).

Peter J. Hawley, Scorpio’s Interim CEO commented, “The newly discovered La Emma zone mineralization, a northern structural zone trending NE from the El Cajón body, is open at depth, and, along with anomalous values in other drilling clearly show that El Cajón remains a robust target with significant upside. Current efforts are directed at advancing the development / production of El Cajón to complement our Nuestra Señora Mine as feed for our plant. The relatively high silver and copper grades of El Cajón and its associated high quality concentrate will add value to the copper concentrate currently being produced. With a strong balance sheet, the Company expects that development costs will be funded internally and accordingly, shareholders of the Company should benefit from a second operating mine with no dilution to the equity of the Company. The NI 43-101 Preliminary Economic Assessment (“PEA”) for El Cajón remains on target for Q4 of this year.”
The new resource estimate demonstrates an increase in tonnage and silver grade as compared to the 2009 estimate (see Table 1). The new estimate also shows a 3% improvement in the ratio of Indicated Resources compared to total resources. MDA prepared both estimates

At the 60 g/t silver equivalent reported resource cut-off, the Indicated Resources, which demonstrate an average grade of 198.1 g/t silver equivalent, display the following changes when compared to the November 2009 estimate:

• Tonnage: 16.5% (368,000 tonnes) increase to 2.597 million tonnes


• Silver resource : 25.7% (2.546 million ounces) increase in silver to 12.451 million ounces


• Copper resource: 21.3% (4.864 million pounds) increase in copper to 27.742 million pounds

At the 60 g/t silver equivalent reported resource cut-off, the Inferred Resources, which demonstrate an average grade of 162.4 g/t silver equivalent, display the following changes when compared to the November 2009 estimate:

• Tonnage: 0.2% (2,000 tonnes) increase to 850,000 tonnes


• Silver resource: 13.6% (400,000 ounces) increase in silver to 3.331 million ounces


• Copper resource: 7.8% (553,000 pounds) increase in copper to 7.679 million pounds

Table 1. Current and Historic Resource Estimates for the El Cajón Project

Prices used to calculate Ag.Eq. in 2009 were Zn $0.80, Pb $0.70, Ag $12.00, Cu $2.00, and Au $750.00
Prices used to calculate Ag. Eq. in 2012 were Zn $0.85 ,Pb $0.85, Ag $24.00, Cu $2.70, and Au $1300.00

Table 2 Change in Indicated Resources
(at 60 g/t Ag. Equivalent – cut off)

El Cajón is a skarn deposit in which mineralization is hosted preferentially along bedding in limestone. Emplacement of mineralized bodies is associated with a granodiorite intrusive and steeply dipping structure. Mineralization is primarily chalcopyrite and tetrahedrite with lesser amounts of sphalerite, galena, and numerous ruby silver minerals. Mineralized lenses dip on the order of 30 through 60 degrees, and are up to 15 meters thick.

El Cajón is currently the subject of numerous environmental, archeological and economic studies which should lead to an exploitation permit application in the coming months. Material from El Cajón is amenable to processing in the Nuestra Señora plant and could become part of the proposed Cosalá Norte Mining and processing complex.

A total of 102 drill holes were used in the estimation of the resource of which 27 were drilled subsequent to the 2009 estimate. Not included in the above estimate are 20 additional holes and the deepening of one hole which were either drilled or assayed after the cut-off date for submission of data for the resource study. Any impact these holes may have on resources will be included in a future resource update.

General methodology used and details on the parameters of the Mineral Resource estimate are as follows:

• The block model is made up of 3m by 3m by 3m blocks and the resource is fully diluted to that block size.


• Geologic cross sections on 25m intervals and long sections on 3m intervals were interpreted.


• Silver, copper, gold, and percent sulfide were each modeled and estimated separately and each with their own set of mineral-domain interpretations.


• Inverse-distance to the second power estimation was used for the reported resource.


• Specific gravity assigned to the blocks in the model varied by sulfide content and mineral zone and ranges from 2.95 g/cm3 to 3.23 g/cm3.


• The number of assays available varied by metal with 2047 assays being available for silver, 1947 for copper and 893 for gold.

Table 3. Mineral Resources — Indicated and Inferred – El Cajón

Notes to Mineral Resources Statement:

1.     Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the estimated Mineral Resources will be converted into Mineral Reserves.

2.     All Mineral Resources have been classified in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the Standards Committee on Reserve Definitions and adopted by the CIM Council on December 11, 2005 and updated on November 27, 2010.

3.     Mineral Resources estimate is as of September 7, 2012.

4.     Silver Equivalent (AgEq) is calculated using metal prices of $24/oz Ag, $1,300/oz Au, $0.85/lb Zn, $0.85/lb Pb, and $2.70/lb Cu.

5.     Silver Equivalent is calculated on a contained-metal basis using the metal prices noted above, without recovery factors taken into account.

6.     Mineral Resources tonnage and contained-metal have been rounded to the nearest thousand and numbers might not add due to rounding.

Technical Information

The Mineral Resources estimate for the El Cajón Development Project was prepared by Mr. Paul Tietz, C. P. G. of MDA, and a “Qualified Person”, as defined in NI 43-101. Mr. Tietz has reviewed and approved the contents of this news release with respect to the Mineral Resource estimates.

Quality Assurance and Quality Control

Scorpio Mining’s Vice President of Exploration, Mr. James Stonehouse, is a Registered Geologist with the Society of Mining Engineers (Registration #4168919) and is a Qualified Person for this disclosure and has supervised the preparation of the technical information submitted to MDA which formed the basis for the updated Mineral Resource estimates disclosed in this press release.

Scorpio Mining’s exploration programs are directly supervised by Mr. Stonehouse, and all technical information for the Company’s projects is obtained and reported under a formal quality assurance and quality control (QA/QC) program. Data used in the updated Mineral Resource estimate comes from numerous drill programs conducted since 1999 and continuing to the present day. For purposes of this new Mineral Resource estimate, the QA/QC program was reviewed in terms of current standards and found to be adequate and typical of databases of this size.

For details of QA/QC procedures and results implemented for all exploration programs, reference should be made to the Company’s website at www.scorpiomining.com.

About Us

Scorpio Mining is a silver producer operating in Mexico with significant base metal by-product credits. In addition, the Corporation has over 40 exploration targets mostly in the vicinity of its current operations.

The Company’s 100% owned Nuestra Señora Mine and plant located in the Cosalá District of Sinaloa State, Mexico, has proven to be a low-cost operation with the benefit of flexible mining methods and diversified metal production. It has a fully mechanized underground operation and a processing facility built for expansion to 4,000 tonnes per day. The plant produces zinc, copper and lead concentrates with a significant silver component in the copper and lead concentrates. Scorpio Mining’s strategy focuses on exploring and developing its existing mineral properties. At the nearby San Rafael and El Cajón deposits, an extensive diamond drilling program is in progress, with the goal of increasing the mineral resource base and ultimately an upgrade to reserve category.

Scorpio Mining also holds a 100% interest in the advanced, high-grade La Revancha silver and Tepozán silver-gold projects, both located in the productive Parral District within the respective states of Chihuahua and Durango, Mexico.

Cautionary Note to U.S. Investors:

Scorpio Mining reports its resource estimates in accordance with standards of the Canadian Institute of Mining, Metallurgy and Petroleum referred to as NI 43-101. These standards are different from the standards generally permitted in reports filed with the SEC. Under NI 43-101, Scorpio Mining reports measured, indicated and inferred resources, measurements which are generally not permitted in filings made with the SEC. According to Canadian NI 43-101 criteria, the estimation of measured resources and indicated resources involve greater uncertainty as to their economic feasibility than the estimation of proven and probable reserves. Under SEC Industry Guide 7 criteria, measured, indicated and inferred resources are considered Mineralized Material. The SEC considers that in addition to greater uncertainty as to the economic feasibility of Mineralized Material compared to proven and probable reserves, there is also greater uncertainty as to the existence of Mineralized Material. U.S. investors are cautioned not to assume that measured or indicated resources will be converted into economically mineable reserves. The estimation of inferred resources involves far greater uncertainty as to their existence and economic viability than the estimation of other categories of resources.

ON BEHALF OF SCORPIO MINING CORPORATION

Peter J. Hawley, Interim CEO

For further information contact:

Victoria Vargas, Vice President Investor Relations and Corporate Communications +1 416-585-2200 Email: [email protected]

Rich Kaiser, YES International: 1-800-631-8127; 001-757-306-6090 (outside North America)
Email: [email protected]

Website: www.scorpiomining.com

This news release includes certain statements that may be deemed “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995 and applicable Canadian securities legislation. Forward-looking statements include, but are not limited to, statements with respect to the Corporation’s operations, exploration and development plans, expansion plans, the discovery and delineation of mineral deposits/resources/reserves, geological interpretations, estimates, expectations, forecasts, objectives, predictions and projections of the future. Generally, these forward-looking statements can be identified by the forward-looking terminology such as “plans”, “expects” or “does not expect”, “is expected”, “budget”, “scheduled”, “estimates”, “projects”, “intends”, “anticipates”, or “does not anticipate”, or “believes”, or “variations of such words and phrases or state that certain actions, events or results “may”, “can”, “could”, “would”, “might”, or “will” be taken”, “occur” or “be achieved”. Forward-looking statements are subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of Scorpio Mining Corporation to be materially different from those expressed or implied by such forward-looking statements, including but not limited to: risks related to the exploration and development and operation of the Corporation’s projects in Mexico, risks related to international operations, construction delays and cost overruns, the actual results of current exploration, development and construction activities, conclusions of economic evaluations, changes in project parameters as plans continue to be refined, future prices of silver, zinc, copper, lead and gold, risks relating to completing acquisition transactions as well as those factors discussed in the sections relating to risk factors of our business filed in Scorpio Mining Corporation’s required securities filings on SEDAR, including its Annual Information Form dated March 26, 2012. Although Scorpio Mining Corporation has attempted to identify important factors that could cause results to differ materially from those contained in forward-looking statements, there may be other factors that cause results to be materially different from those anticipated, described, estimated, assessed or intended.

There can be no assurance that any forward-looking statements will prove accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. Scorpio Mining Corporation does not undertake to update any forward-looking statements that are incorporated by reference herein, except in accordance with applicable securities laws.