VANCOUVER, BRITISH COLUMBIA--(Marketwire - Sept. 12, 2012) - Trevali Mining Corporation ("Trevali" or the "Company") (News - Market indicators)(TSX:TV.WT)(OTCQX:TREVF)(LMA:TV)(FRANKFURT:4TI) announces that construction at its Santander Zinc-Lead-Silver Mine in west-central Peru is progressing well and commissioning is anticipated in the fourth quarter.

SITE INFRASTRUCTURE

All core site infrastructure is now complete and fully operational - accommodation units, catering facilities and various mine planning and site offices. Construction and commissioning of the project's 65-kilometre power-line is nearing completion and the minesite will be connected to the Peruvian power grid prior to commissioning.

PROCESSING PLANT

Merit Consultants International Inc. continues to supervise construction of the 2,000 tonne-per-day (tpd) Processing Plant by Cempro Tech S.A., a Lima based specialist construction firm, on behalf of the Santander Project Development Team (a joint development between Trevali and Glencore International).

Construction of the Plant is progressing: the mills are installed, the flotation building erected and the flotation cells are installed, crusher and zinc and lead thickener foundations completed, new steel for mill and crusher buildings is on site and is being erected and the crushers are being installed, tailings dam sealing is ongoing and mineral stockpile preparation is advanced (Figure 1).

UNDERGROUND DEVELOPMENT

The Company's mining contractors, JRC Ingenieros, have been actively advancing underground development on the three Magistral deposits with three crews fully staffed and equipped. All key underground service and support facilities are in place, namely water, air, underground offices and training rooms, lamp-room, various explosive magazines and equipment shops (Figures 2 and 3).

Based on current development schedules it is anticipated that approximately 95,000 tonnes of mineralized material grading 5.61% Zn, 0.65% Pb and 1.65 oz/t Ag will be stockpiled and available for mill commissioning.

To view Figures 1 to 3, visit the following link: http://media3.marketwire.com/docs/Trevali_Figures1to3.pdf

ABOUT TREVALI MINING CORPORATION

Trevali is a zinc-focused base metals developer with operations in Canada and Peru - the Halfmile and Santander mines respectively. In Canada, Trevali owns the Halfmile zinc-lead-silver mine and Stratmat polymetallic deposit, and has entered into a definitive agreement to acquire the Caribou Mine and Mill, all located in the Bathurst Mining Camp of northern New Brunswick. The Company also has the past-producing Ruttan copper-zinc mine in northern Manitoba. Initial production from the Halfmile mine commenced in early 2012 and development is ramping up to achieve a planned production rate of approximately 3,000-tonnes-per-day to feed planned operations at the Company's Caribou Mill Complex (subject to closure of its acquisition).

In Peru, the Company has the Santander zinc-lead-silver mine and the former-producing Huampar silver mine, both located in the Central Peruvian Polymetallic Belt. Mine commissioning is anticipated to commence at the Santander operation in late-2012 with ramp up to full 2,000-tonnes-per-day production to follow shortly thereafter. Additionally through its wholly-owned subsidiary, Trevali Renewable Energy Inc., Trevali is undertaking a significant upgrade of its wholly-owned Tingo run-of-river hydroelectric generating facility along with transmission line upgrades and extensions to allow, in addition to supplying power to the mining operation on the property, the potential sale of surplus power into the Peruvian National Energy Grid.

The common shares of Trevali are listed on the TSX (symbol TV), the OTCQX (symbol TREVF) and on the Lima Stock Exchange (symbol TV). Warrants to purchase common shares of Trevali are listed on the TSX (symbol TV.WT). For further details on Trevali, readers are referred to the Company's web site (www.trevali.com) and to Canadian regulatory filings on SEDAR at www.sedar.com.

On Behalf of the Board of Directors of TREVALI MINING CORPORATION

Mark D. Cruise, President

This news release contains "forward-looking statements" within the meaning of the United States private securities litigation reform act of 1995 and "forward-looking information" within the meaning of applicable Canadian securities legislation. Statements containing forward-looking information express, as at the date of this news release, the Company's plans, estimates, forecasts, projections, expectations, or beliefs as to future events or results and the company does not intend, and does not assume any obligation to, update such statements containing the forward-looking information. Such forward-looking statements and information include, but are not limited to statements as to: the accuracy of estimated mineral reserves and resources, anticipated results of future exploration, and forecast future metal prices, anticipated results of future electrical sales and expectations that environmental, permitting, legal, title, taxation, socio-economic, political, marketing or other issues will not materially affect estimates of mineral reserves. These statements reflect the Company's current views with respect to future events and are necessarily based upon a number of assumptions and estimates that, while considered reasonable by the Company, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies.

These statements reflect the Company's current views with respect to future events and are necessarily based upon a number of assumptions and estimates that, while considered reasonable by the company, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Many factors, both known and unknown, could cause actual results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements contained in this news release and the company has made assumptions and estimates based on or related to many of these factors. Such factors include, without limitation: fluctuations in spot and forward markets for silver, zinc, base metals and certain other commodities (such as natural gas, fuel oil and electricity); fluctuations in currency markets (such as the Peruvian sol versus the U.S. dollar); risks related to the technological and operational nature of the Company's business; changes in national and local government, legislation, taxation, controls or regulations and political or economic developments in Canada, the United States, Peru or other countries where the Company may carry on business in the future; risks and hazards associated with the business of mineral exploration, development and mining (including environmental hazards, industrial accidents, unusual or unexpected geological or structural formations, pressures, cave-ins and flooding); risks relating to the credit worthiness or financial condition of suppliers, refiners and other parties with whom the Company does business; inadequate insurance, or inability to obtain insurance, to cover these risks and hazards; employee relations; relationships with and claims by local communities and indigenous populations; availability and increasing costs associated with mining inputs and labour; the speculative nature of mineral exploration and development, including the risks of obtaining necessary licenses and permits and the presence of laws and regulations that may impose restrictions on mining,; diminishing quantities or grades of mineral reserves as properties are mined; global financial conditions; business opportunities that may be presented to, or pursued by, the Company; the Company's ability to complete and successfully integrate acquisitions and to mitigate other business combination risks; challenges to, or difficulty in maintaining, the Company's title to properties and continued ownership thereof; the actual results of current exploration activities, conclusions of economic evaluations, and changes in project parameters to deal with unanticipated economic or other factors; increased competition in the mining industry for properties, equipment, qualified personnel, and their costs. Investors are cautioned against attributing undue certainty or reliance on forward-looking statements. Although the Company has attempted to identify important factors that could cause actual results to differ materially, there may be other factors that cause results not to be as anticipated, estimated, described or intended. The Company does not intend, and does not assume any obligation, to update these forward-looking statements or information to reflect changes in assumptions or changes in circumstances or any other events affecting such statements or information, other than as required by applicable law.

Trevali's production plans at Halfmile-Stratmat and Santander are based only on Indicated and Inferred Mineral Resources and not Mineral Reserves and do not have demonstrated economic viability. Inferred Mineral Resources are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as Mineral Reserves, and there is therefore no certainty that the conclusions of the production plans and Preliminary Economic Assessment (PEA) will be realized. Additionally where Trevali discusses exploration/expansion potential, any potential quantity and grade is conceptual in nature and there has been insufficient exploration to define a mineral resource and it is uncertain if further exploration will result in the target being delineated as a mineral resource.