News Releases

September 22, 2010

Metalline Mining Updates Progress on the Sierra Mojada Project, Coahuila, Mexico

Greenwood Village, Colorado - Metalline Mining Company (MMG: NYSE AMEX, MMZ: TSX) is pleased to provide an update on progress at the Sierra Mojada Project, located in Coahuila, Mexico. A new power point presentation is posted to the web, which is being used in investor presentations going forward beginning this week. 

The Company has received a report on the deportment of silver and zinc from a sample taken from the shallow silver-zinc resource from the San Salvador shaft area at approximately 100 meters depth along section 631500E, a cross section of which was posted to the web earlier. The deportment study demonstrates the likely methods for recovery of silver, zinc, and lead.

The head grade of the sample was 568 gpt Ag, 4.2% Zn, and 1% Pb. This is higher than expected average grade but was chosen to make sure there were ample quantities of silver and zinc to recover. Silver is contained mostly in acanthite (Ag2S) and silver halides, both of which are very soluble in cyanide. Silver extractions in cyanide were 80% (at -100 mesh) to 91% (at -250 mesh), depending upon grind size and the degree of liberation of the silver-bearing minerals. Zinc is contained almost exclusively in smithsonite (ZnCO3). Separately, smithsonite was concentrated by heavy media (HML) separation to remove the silicates, then separated from both cerrusite (PbCO3) and limestone/dolomite fractions using a super-panner on the HML heavy mineral separate. Zinc concentrate grades of 25-31% were achieved, with a total recovery of ~75%. Much work remains on complete separation of zinc and silver to maximize recovery of both metals. Lead should be recoverable by either gravity or flotation methods due to the higher density of cerrusite compared with that of smithsonite and the carbonate gangue minerals. 

The Company has solicited metallurgical testing proposals from five laboratories with experience in gravity, flotation, and cyanidation mineral processing, is reviewing the proposals received, and will make a selection for proceeding with test work in the next several days. NITON instrument surveying of the material exposed in the metallurgical trench reveals the zone as exposed is ~70 meters wide and averages roughly 75 gpt Ag, 2% Zn and 0.3% Pb, which is very near the anticipated average grade of the resource. Channel sampling of the trench is completed and samples are in the lab with results expected shortly. Bulk samples from this trench will be collected and sent to the selected metallurgical lab for commencement of metallurgical testing towards the end of the month.

Drilling continues on the shallow silver-zinc resource with two contractor core rigs drilling HQ core and one company RC drill rig drilling pilot holes through 25-50 meters of alluvium for the contractor core drills. Assays from these holes will be reported by section as drilling on each section is completed and assays are received and have passed QA/QC protocols. Several new assay sections will be reported in the next week or two.

Greg Hahn, Interim President and CEO, a Certified Professional Geologist, is the Qualified Person responsible for reviewing and reporting the contents of this press release and assuring the results reported herein are in accordance with NI 43-101.

About Metalline Mining Company

Metalline Mining Company is focused on the acquisition, exploration and development of mineral properties. Metalline currently owns mineral concessions in the municipality of Sierra Mojada, Coahuila, Mexico and holds licenses in Gabon, Africa. Metalline 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 (

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") and constitute "forward looking information" within the meaning of Canadian securities laws. These statements include statements about Metalline's planned drilling program and are based on material factors and assumptions including Metalline's management's 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 the risk that Metalline's drill program may not be successful or result in the discovery of commercially mineable deposits of ore and those risks identified in Metalline's Annual Report on Form 10-K for the fiscal year ended October 31, 2009 under "Risk Factors, " and in subsequent reports filed with the Securities and Exchange Commission. 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.