Mongolian Resource Play

[Tackler]

Denison Mines gets resource estimate for Hairhan JV

2007-03-13 07:56 MT - News Release

Mr. Peter Farmer reports

DENISON ANNOUNCES NI 43-101 RESOURCE ESTIMATE ON HAIRHAN DEPOSIT IN MONGOLIA

Denison Mines Corp. has received an independent resource estimate on its Hairhan deposit within its Gurvan Saihan joint venture in Mongolia. Denison holds a 70-per-cent interest in the GSJV with the government of Mongolia, which holds 15 per cent, and the Russian government, through Geologorazvedka, which holds the remaining 15 per cent. The GSJV was formed in 1994 under a unique mineral agreement with the government of Mongolia. The estimate was prepared by Scott Wilson Roscoe Postle Associates Inc. in accordance with the requirements of National Instrument 43-101.

The GSJV currently has licences encompassing approximately 750,000 hectares and comprises the Hairhan, Gurvan Saihan, Choir, Ulziit, Urt Tsav and Hokh Tolgoi projects. The following resource estimates cover only the Hairhan deposit and the Haraat deposit, located within the Choir project area. In addition to the 70-per-cent-held GSJV properties, Denison holds a 100-per-cent interest in five other properties: Bayankhongor, Tsagaan Ovoo, Gobiguulin, Gobiguulin-2 and Gobiguulin-3, comprising 322,580 hectares.

In the report titled "Technical Report on the Uranium Exploration Properties in Mongolia" dated Feb. 27, 2007, Scott Wilson RPA estimated the Hairhan mineral resource detailed in the accompanying table using a cut-off of 0.1 metre per cent (grade times thickness, or GT) over a minimum of one metre. The average thickness of the indicated resources is 5.2 m and of the inferred resources is 5.7 m.

 
    HAIRHAN CURRENT MINERAL RESOURCE ESTIMATE  
    SCOTT WILSON ROSCOE POSTLE ASSOCIATES INC. 
  
            Tonnes   Grade                     U3O8 
 Category   (000s)    % U    Tonnes U   (million lb) 
  
 Indicated   4,726   0.064      3,036           7.9 
 Inferred    1,848   0.073      1,341           3.5 
 

For the Haraat deposit, Scott Wilson RPA considered the resource estimates prepared by Geologorazvedka in 1997 and 1998, and, after reviewing the available data, including gamma logs and chemical analysis from core samples, concluded that this methodology was reliable and relevant. These mineral resources were classified as C1 (indicated) and C2 (inferred) using the Russian system. Scott Wilson RPA considered the mineral resources at Haraat to be historical mineral resources and equivalent to inferred under the CIM definition standards. Denison is not treating the resource estimates as NI 43-101 compliant. The historical estimates should not be relied upon.

HARAAT HISTORICAL MINERAL RESOURCE ESTIMATE
SCOTT WILSON ROSCOE POSTLE ASSOCIATES INC.

Tonnes Grade U3O8
Category (000s) % U Tonnes U (million lb)

Inferred 10,600 0.023 2,461 6.4

Note: Cut-off grade is 0.01 per cent U.

The GSJV's targets have been uranium deposits amenable to ISR (in situ recovery) techniques. Initial testing to determine the amenability of both the Haraat and Hairhan deposits to ISR methods was done in 1997 and 1998. While the tests remain incomplete, it is considered that standard ISR using acid leach will be effective in recovering uranium in both deposits.

These resource estimates represent the resources currently defined below the water table and amenable to ISR. The GSJV has identified significant mineralization which is above the water table at both Hairhan and Haraat. During 2007, Denison will be evaluating the potential of open pit/heap leach as an alternative to ISR. If successful, this could considerably increase the GSJV's resource estimates. In addition, Denison's 2007 Mongolian work program includes over 80,000 metres of resource delineation, hydrogeological and exploration drilling, environmental permitting and engineering design. Denison is also participating with its other joint venture partners on exploration in east-central and southern Mongolia.

Scott Wilson RPA was retained to independently review and audit the mineral resources at the Hairhan and Haraat projects. Neil Gow, PGeo, and Thomas Pool, PE, are the qualified persons pursuant to National Instrument 43-101 who have verified the data disclosed and were responsible for the report. Mr. Gow and Mr. Pool have reviewed the technical contents related to the resource estimates contained in this release. A copy of the report will be available on SEDAR.