Argentex: Excellent recovery of gold and silver from preliminary
metallurgical testing on Pinguino

VANCOUVER, May 25 /CNW/ - Argentex Mining Corporation (TSX-V: ATX, OTCBB: AGXM) is pleased to announce results from its preliminary metallurgical testing program. This is part of the company's ongoing Preliminary Economic Assessment (scoping study) of the Pinguino project, which is scheduled for completion at the end of the current quarter.

"We are encouraged by the results of these preliminary metallurgical tests as they are the first indication of potential recoveries at Pinguino," said Ken Hicks, President of Argentex. "We view these results as a positive step in our efforts to advance the Pinguino project as we continue working to determine the economic viability of the deposit."

Two different types of mineralization believed to be representative of the mineralization at Pinguino were selected for study: oxide precious metal and primary polymetallic sulphide. Independent engineering and metallurgical specialists developed and implemented test programs carried out at an independent laboratory.

Results

Gold extraction by cyanide leaching of samples of oxide ore from three mineralized zones were high, ranging from approximately 95 to 98 percent. Silver extractions ranged between 74 and 96 percent. The three samples tested had gold feed grades ranging from 0.34 to approximately 14 grams per tonne (g/t). The silver contents in the feed ranged from approximately 260 to 726 g/t. The proportion of feed gold, which reported to the pan concentrate, was variable but quite high for Marta Este and Marta Norte. On average approximately 65 percent of the feed gold was recovered to the pan concentrate for the Marta Este composite. Each sample was tested at a target primary grind for particle sizing of 100 and 150 microns K80, which is a relatively coarse grind.

Sulphide mineralization was tested with a selected sample from Marta Centro, the largest polymetallic vein discovered to date on the Pinguino property. Recoveries of lead and zinc were favourable with more than 90 percent recoveries to their respective concentrates and 60 percent of silver reporting to the lead concentrate. The sample was ground to a nominal 102 microns K80.

Indium assays remain to be completed and are in process now.

Scope of work for preliminary metallurgical testing at Pinguino

The scope of work for the oxide precious metal group involved chemical and mineral scope analyses and metallurgical testing on composite samples from three mineralized zones that are believed to be representative end members of mineralization at the Pinguino project. The zones that were represented by the samples tested were identified as Marta Norte, Marta Noroeste and Marta Este. These mineralized zones were considered as essentially being precious metal targets with low sulphur and elevated precious metal contents.

Polymetallic sulphide work consisted of a standard two product preliminary rougher flotation focused on a sample of high-grade sulphide-rich material from the Marta Centro vein, which represents the largest and thickest polymetallic silver-zinc-lead vein discovered at Pinguino to date.

Preliminary flowsheets to determine appropriate process parameters based on the metallurgical test work have been developed for each type of mineralization.

Metallurgical test work is being conducted by independent contractor G&T Metallurgical Services Ltd. of Kamloops, British Columbia, Canada, specialists in metallurgical testing and analytical services. Metallurgical work is being supervised by John Thomas, Ph.D., technical expert, and Robert J. Morris, M.Sc., P.Geo., through general engineering contractor Moose Mountain Technical Services. Mr. Morris is an independent Qualified Person as defined by Canada's National Instrument 43-101. The test data will be used by Moose Mountain Technical Services to develop a preliminary process flowsheet, to identify further testing requirements, and to develop capital and operating costs for the scoping study that is scheduled to be completed in the current quarter. The results of the forthcoming PEA and details of this metallurgical testing are required to be reported in a NI 43-101-compliant technical report 45 days after completion.

Readers are cautioned that this information is preliminary in nature and deals with a limited number of selected samples, though the Company believes them to be representative samples. As the project advances, more extensive metallurgical testing and engineering work would be required as part of a more in-depth evaluation.

About Pinguino

Pinguino is located in Argentina's Patagonia region, within the Deseado Massif of Santa Cruz province. With more than 74 line kilometers of veins discovered to date, the Pinguino property is host to the largest known undeveloped vein system in Santa Cruz province after the developed AngloGold Ashanti Cerro Vanguardia mine. Both vein systems fall within the Tranquilo trend, a major northwest structural corridor in central Santa Cruz.

Mineralization at Pinguino is unique in the region, containing silver-indium-zinc-lead-gold in multiple zones that remain open-ended along strike and to depth. To date, Argentex has drilled 333 holes at Pinguino for a total of 33,559 meters.

Pinguino is easily accessible, situated approximately 400 meters above sea level in low-relief topography. An existing system of all-weather roads provides year-round access to the property.

Quality Assurance

Exploration samples selected for analysis are sent to Acme Analytical Laboratories' sample preparation lab in Mendoza, Argentina. From there sample pulps are sent to Santiago, Chile for fire assay gold analysis and to Vancouver, Canada for Group 1DX multi-element MS-ICP analysis. Samples with over-limit zinc, lead, silver and/or copper are reanalyzed using an ore-grade high detection limit 7AR analysis, also conducted in Vancouver. Acme Analytical Laboratories is an accredited ISO 9000:2001 full-service commercial laboratory with its head office in Vancouver. Referee analyses will be carried out by ALS Chemex in Mendoza, Argentina and La Serena, Chile. Argentex, Acme and ALS Chemex all maintain comprehensive and independent Quality Control/Quality Assurance programs.

G&T Metallurgical Services Ltd. of Kamloops, British Columbia, Canada, are specialists in metallurgical testing and analytical services. The company was incorporated in Kamloops B.C. in 1990, constructing a modern and well-equipped mineral processing research and development complex. They offer a wide range of services assisting major to junior mining companies including sample preparation, mineral processing testing, mineralogical/modal analysis and chemical analysis.

ABOUT ARGENTEX:

Argentex Mining Corporation is a Delaware corporation. It is a junior mining company in the exploration stage with significant holdings in the Patagonia region of Argentina. In total, the company owns 100% mineral rights to more than 35 properties with approximately 141,020 hectares of prospective land located in the Santa Cruz and Rio Negro provinces of Argentina, including the Pinguino property. Shares of Argentex common stock trade under the symbol AGXM on the OTCBB and on the TSX Venture Exchange under the symbol ATX.

Qualified Persons

Exploration on the Pinguino property is being conducted under the supervision of Mr. Kenneth Hicks, P.Geo., Argentex's President and a Qualified Person as defined by Canada's National Instrument 43-101. Mr. Hicks has read and approved the contents of this release. Mr. Hicks is not considered independent of the issuer. Robert J. Morris, M.Sc., P.Geo., through general engineering contractor Moose Mountain Technical Services, is an independent Qualified Person as defined by Canada's National Instrument 43-101. Mr. Morris has read and approved the contents of this release.

Neither 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.

Statements in this news release that are not historical facts are forward-looking statements that are subject to risks and uncertainties. Words such as "expects", "intends", "plans", "may", "could", "should", "anticipates", "likely", "believes" and words of similar import also identify forward-looking statements. Forward-looking statements in this press release include the Company's anticipation that the Preliminary Scoping Study of the Pinguino project will be completed on schedule at the end of the current quarter. Actual results may differ materially from those currently anticipated due to a number of factors beyond the Company's control. These risks and uncertainties include, among other things, competition for qualified personnel and risks that are inherent in Argentex's operations including the risk that the Company may not find any minerals in commercially feasible quantity or raise funds sufficient to prosecute its exploration plans. These and other risks are described in the Company's Annual Report on Form 10-K and other filings with the Securities and Exchange Commission.

For further information: Ken Hicks, President, Argentex Mining Corporation, 1-866-594-7687, [email protected]