COEUR D'ALENE, Idaho, March 25 /PRNewswire-FirstCall/ -- Metalline Mining Company (Amex: MMG) announces progress on its feasibility study on the Sierra Mojada project. Metalline President Merlin Bingham said, 'Metalline management is very pleased with the progress that is being made on moving the definitive feasibility study towards completion.'

Late in the week of 2 March, 2008, Metalline Mining Company executives met with engineers from its lead consultant, Green Team International, to review and evaluate the results to date of activities on the feasibility study for exploitation of the oxide zinc resource at Sierra Mojada, Coahuila, Mexico.

Mining Plan. Currently, the mine plan projects an underground mine with a daily production rate of a minimum of 3,000 tonnes (metric tons) per day (tpd), and a minimum 17-year mine life. The plan, prepared by engineers at Pincock Allen and Holt (PAH), evaluated both open pit and underground mine alternatives. The open pit alternative was rejected due to very high stripping ratios and both high operating costs (opex) and high preproduction stripping capital costs (capex), costs much greater than for the underground mining alternative. Underground mining would use a long-hole end-slice panel stoping method to perform high-volume relatively low-cost mining. The method selected is governed by the geotechnical study on rock strength and operational considerations such as capital costs, operating costs, production rate and mine life.

PAH engineers have strongly recommended a test mining program to confirm the planned mining method and validate the geotechnical data. The first phase of the test mining program is recommended to consist of driving the production decline to the selected test mine area near the center of the resource and constructing initial access development workings to the test area. The second phase would involve test mining.

The Board of Directors of Metalline has carefully reviewed the PAH recommendations and has directed management to prepare for the test mining program. Management has requested that PAH prepare a test mine proposal of sufficient detail to enable the proposal to be presented to contractors for bidding the project.

Metallurgy and Concentrator. A second large and representative bulk sample, selected from within the volume of mineralized material used in our resource model, was obtained in late 2007 and shipped to Johannesburg, South Africa. The material is being processed at Mintek laboratory to confirm the results of previous metallurgical studies and to provide a volume of concentrate for evaluation and testing. Additional testing will be done on samples containing 7 to 10% zinc, the range of values representing the average grade of run-of-mine material indicated by block models and mining studies, in order to more accurately estimate the recovery and concentrate expected from such material.

Metallurgical studies on silver recovery indicates that silver in the zinc oxide materials report to the concentrate with better than 80% recovery of the contained silver. A resource model of the silver distribution in the oxide zinc material is being expedited to help determine whether recovery of by-product silver is economically justified, and various methods available to recover silver from the concentrate continue to be studied.

Economic Models. We are evaluating several economic models to determine the most effective way to exploit the deposit. Two of the models involve construction of a zinc refinery to treat concentrates from Sierra Mojada. The third involves sale of concentrate to existing third party refineries. The third option involves a much smaller capital expenditure and is attractive if satisfactory treatment charges can be obtained. Some of the concentrate currently being produced at Mintek will be used to evaluate this option. The results of the economic models are attractive given the current level of precision (plus or minus 20-30%) of study results.

Future Work. The mine and concentrator studies are continuing to greater levels of detail so that cost estimates can be improved to the level of precision required for a definitive feasibility study (plus or minus 10-15%). Discussions will be held with potential concentrate buyers to determine whether a market for Sierra Mojada concentrate exists on terms that are attractive to us and competitive with the refinery options. Methods for improving the concentrate grade are being investigated together with methods to recover by-product silver.

The Company is continuing to evaluate the high-grade silver potential located north of and adjacent to the oxide zinc mineralization to determine whether mining of both mineral systems can be conducted.

Metalline Mining Company is an exploration stage enterprise engaged in the business of mining. The Company currently owns mining concessions in the municipality of Sierra Mojada, Coahuila, Mexico. The Company conducts its operations in Mexico through its wholly owned Mexican subsidiaries, Minera Metalin S.A. de C.V. and Contratistas de Sierra Mojada S.A. de C.V. To obtain more information on Metalline Mining Company, visit the Company's web site (http://www.metalin.com).

Forward-Looking Statements

This news release contains forward-looking statements regarding future events and Metalline's future results that are subject to the safe harbors created under the Securities Act of 1933 (the 'Securities Act') and the Securities Exchange Act of 1934 (the 'Exchange Act'). These statements are based on current expectations, estimates, forecasts, and projections about the industry in which Metalline operates and the beliefs and assumptions of Metalline's management. Words such as 'expects,' 'anticipates,' 'targets,' 'goals,' 'projects,' 'intends,' 'plans,' 'believes,' 'seeks,' 'estimates,' 'continues,' 'may,' variations of such words, and similar expressions, are intended to identify such forward-looking statements. In addition, any statements that refer to projections of Metalline's future financial performance, Metalline's anticipated growth and potentials in its business and other characterizations of future events or circumstances are forward-looking statements. Readers are cautioned that these forward-looking statements are only predictions and are subject to risks, uncertainties, and assumptions that are difficult to predict, including those identified elsewhere herein and Metalline's Annual Report on Form 10-KSB for the fiscal year ended October 31, 2007 under 'Risk Factors.' Therefore, actual results may differ materially and adversely from those expressed in any forward-looking statements. Metalline undertakes no obligation to revise or update any forward-looking statements for any reason.

SOURCE Metalline Mining Company