MDN Inc./Update on Metallurgical Work at the Crevier Project: Positive Hydrometallurgy Results


MONTREAL, QUEBEC--(Marketwire - Feb. 9, 2012) -

Editors' Note: There is a graphic associated with this press release.

MDN Inc. ("MDN") (TSX:MDN) is pleased to provide an update on the progress of metallurgical testing for its Crevier niobium-tantalum property. The Crevier property is located north of Girardville in the Quebec's Saguenay-Lac-Saint-Jean region, and is 72.5% owned by MDN Inc. and 27.5% by IAMGOLD. The metallurgy work is being done as part of a feasibility study now underway.

Mineral processing of the Crevier ore is done in two separate stages: flotation to produce a concentrate containing niobium and tantalum, and leaching (hydrometallurgy) to recover the niobium and tantalum oxides contained in the concentrate.

Leaching Process

The HF leaching program has been underway since November 2011. The goal of the program is to recover the niobium and tantalum oxides contained in a concentrate produced by pilot plant flotation testing done in 2011. The work is being carried out by SGS Lakefield.

To date, test results appear to confirm the assumptions used in the preparation of the Crevier project Preliminary Economic Assessment and show that there could be an improvement in the parameters used. The optimization factors currently underway are:

  • Confirmation of the percentage of niobium and tantalum extracted on dissolution of the concentrate
  • Potential for the elimination of the pre-leaching stage of the process, which would reduce the capital costs associated with refinery construction, as well as operating costs
  • A reduction in the consumption of the hydrofluoric acid used for leaching, which could result in a significant reduction in refinery operating costs, as hydrofluoric acid is a major component of production costs
  • Results obtained to date indicate the possibility of producing zirconium oxide, an economic by-product not accounted for in earlier studies.

This program, which is required to complete the feasibility study, will continue in the coming months, with selective recovery testes for niobium and tantalum oxides.

Flotation Process

Pilot plant testing performed in 2011 did not generate the expected results. This entire portion of the processing of the Crevier project ore had to be reviewed due to variability in the recovery rate for different test days and higher reagent consumption.

In light of the excellent results generated by the leaching program, the Company has decided to carry out a second pilot plant test to improve the ore treatment process. Preparations are now underway, and the test will be done in May and June, depending on the availability of the SGS Lakefield laboratory. Once the date is confirmed, the timetable for the entire feasibility study will be revised accordingly.

"Despite this delay in the preparation of the feasibility study, we reiterate our confidence in the potential of the Crevier project and our interest in its development. This optimization of the ore treatment process will give us the confidence we need to make a construction decision for this new mining project," said Serge Bureau, President and Chief Executive Officer of MDN.

About MDN

MDN Inc. (TSX:MDN) is a mining exploration and development company exploring and developing projects in Quebec and Tanzania. The company is also active in the search for new business opportunities that can increase shareholder value. As well as holding a 30% participating interest in the Tulawaka gold mine, MDN has also discovered gold in Tanzania at the Ikungu property, where four high-grade gold zones have been identified. MDN Inc. also owns a 72.5% interest in Crevier Minerals Inc., which owns an NI 43-101 niobium-tantalum resource in the Lac-Saint-Jean area of Quebec. MDN has an option to increase its interest in Crevier Minerals Inc. to 87.5%. Additional information is available on MDN's website at www.mdn-mines.com.

Forward-Looking Statements Other than statements of historical fact, all statements in this release that address events or developments that the Company expects to occur are forward-looking statements. Although the Company believes that the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guarantees of future performance, and actual results may differ materially from those in the forward-looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements are discussed in greater detail in the Company's most recent Annual Information Form filed on SEDAR, which also provides additional general assumptions in connection with these statements. Investors and others who base themselves on the Company's forward-looking statements should carefully consider the factors mentioned in the Annual Information Form as well as the uncertainties they represent and the risk they entail. The Company believes that the expectations reflected in those forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct, and as such, the forward-looking statements in this press release should not be unduly relied upon. These statements speak only as of the date of this press release.

To view the graphic associated with this press release, please visit the following link: http://media3.marketwire.com/docs/mdn_eng_0209.pdf

Contact Information:

Serge Bureau, Ing.
President and Chief Executive Officer
MDN Inc.
514 866-6500, Ext. 221

Vincent Janelle
Investor Relations
MDN Inc.
514 866-6500, Ext. 228
vjanelle@mdn-mines.com

Marc Boisvert, Ing.
Vice President, Exploration
MDN Inc.
514 866-6500, Ext. 227

HF leaching