Mr. David Adamson reports

RUBICON MINERALS RECEIVES POSITIVE PRELIMINARY ECONOMIC ASSESSMENT FOR F2 GOLD SYSTEM, PHOENIX GOLD PROJECT, RED LAKE, ONTARIO

Rubicon Minerals Corp. is releasing the positive results of a preliminary economic assessment for its 100-per-cent-owned F2 gold system, part of its Phoenix gold project located in the heart of the Red Lake, Ont., gold district. The PEA was prepared by AMC Mining Consultants (Canada) Ltd. with metallurgical sections prepared by Soutex Inc., both of which are independent of the company.

                 PRELIMINARY ECONOMIC ASSESSMENT HIGHLIGHTS
                        (All amounts in U.S. dollars)

                                       Base case ($1,100 oz gold) *Spot price case ($1,500 oz gold)

Average mined gold grade                  13.87 g/t                  13.87 g/t                       
Steady-state annual gold production       180,000 ounces             180,000 ounces                  
Life of mine from production start        12 years                   12 years                        
Planned steady-state production rate      1,250 tpd                  1,250 tpd                       
IRR pretax                                28%                        48%                             
NPV pretax (5-per-cent discount rate)     $433-million               $933-million                    
Payback period from start of production   3.3 years                  2 years                         
NPV pretax (0-per-cent discount rate)     $739-million               $1,482-million                  
Initial capital (30-per-cent contingency) $214-million               $214-million                    
Cash costs                                $214/tonne                 $214/tonne                      
Metallurgical recovery                    92.5%                      92.5%                           
Total mined gold to mill**                2,006,000 ounces           2,006,000 ounces                

* Three-year trailing average gold price. Tabulated results exclude NSR
royalty of 1.5 per cent. Results based on $1 (Cdn) equals $1 (U.S.) exchange rate.
** The mine plan and financial outputs are based on a mining cut-off
grade of six grams per tonne and a life of mine of 12 years, utilizing two million
ounces (72-per-cent recovery) of the currently identified resources.

This PEA is preliminary in nature as it includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves and there is no certainty that the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

The PEA is based on an updated mineral resource estimate containing an indicated mineral resource of 1,028,000 tonnes grading 14.5 grams per tonne gold (477,000 ounces of gold) and an inferred mineral resource of 4.23 million tonnes grading 17.0 g/t gold (2,317,000 ounces of gold); both the PEA and the resource estimate have been prepared by AMC. The mineral resource estimates were prepared by Dinara Nussipakynova, PGeo, Cath Pitman, PGeo, and Mort Shannon, PGeo, consulting geologists of AMC and independent qualified persons as defined by NI 43-101.

The accompanying table shows a summary of the mineral resource estimates.

SUMMARY OF AMC MINERAL RESOURCE ESTIMATES
                                  
Classification  M tonnes  Au g/t  M oz Au

Indicated        1.028     14.5    0.477 
Inferred         4.230     17.0    2.317 

Notes: 
- CIM definitions were used for mineral 
resources.
- The cut-off grade applied is 
five g/t Au.
- A capping value of 270 g/t Au has 
been applied to the composites.
- Using drilling results to Feb. 28, 
2011.
- The figures above are "total" 
resources.

Inferred resources are too speculative to have economic considerations applied to them and there is no certainty that the inferred resources will be converted to measured and indicated resources.

If the data are not capped, the totals are 1,135,000 tonnes at 17.2 grams per tonne gold for 634,000 ounces for the indicated category and 4,129,000 tonnes at 21.2 g/t Au for 2,842,000 ounces for the inferred category.

"The PEA is a very good start. It indicates that the F2 gold system is a potentially viable project capable of producing a steady-state average of 180,000 ounces of gold per year and over 200,000 ounces at its peak using conventional mining and processing techniques with an initial capital investment of $214-million. The use of a 30-per-cent contingency on capital costs represents a reasonably conservative approach which recognizes the reality of cost escalation in the industry. We are also pleased to have been able to convert a significant portion of resources to the indicated category. The deposit remains open in all directions and the PEA outlines a number of areas for potential future optimization. Management considers the range of results presented by AMC to be largely consistent with our most recent (March 31, 2011) resource estimates with the important difference of the conversion of some previously categorized inferred resources to a significant indicated resource component in the new AMC estimates," stated David Adamson, president and chief executive officer.

Project description

The F2 gold system is part of the 100-per-cent-owned Phoenix gold project in Red Lake, Ont. The project is accessible by road. Red Lake is an established mining town with access to full services.

Mining plan

The PEA considers development of the F2 gold system as an underground mine at a steady state rate of 1,250 tonnes per day. The primary mining method is conventional cut and fill utilizing paste fill to maximize the material returned underground. The mine plan and financial outputs are based on a two-year preproduction phase and a producing mine life of 12 years, utilizing two million ounces, representing 72 per cent of the currently identified resources. It should be noted that, in determining the mining inventory, AMC decided to take a conservative mine planning approach in applying the average diluted resource grade to the bottom five mining horizons (bottom 305 metres of the resource) rather than use the modelled average grade of 33.8 g/t, thus reducing the total ounces on these levels. The company aims to continually upgrade the available resource for mining through definition drilling. An opportunity may also exist to drive a ramp from surface to accelerate the production in the upper part of the deposit in the early years of the project, thus changing the cash flow of the potential mine.

Metallurgy and processing

Rubicon extracted one approximately 1,200-tonne bulk sample from the top of the F2 core zone and a second approximately 1,000-tonne bulk sample to the west from the WLB2 zone. The purpose of these samples was to establish the metallurgical performance of the two zones. Soutex was retained to conduct the mill design and engineering and manage the laboratory work required to ensure the mill design criteria were understood. Two 10-tonne subsamples were sent to G&T Laboratories for further process analysis. The remainder of the material was shipped to SMC McAlpine mill. During milling, the material was sampled and tested at Swastika Laboratories Ltd. under the supervision of Soutex. The samples were taken at periodic intervals from the mill stream (float concentrate, gravity concentrate and tailings) and combined to provide a metallurgical balance for the total gold content of the bulk sample.

Results of processing work indicate processing will be straightforward and will be a combination of gravity followed by a conventional carbon-in-leach process. Gold recoveries are estimated to be 92.5 per cent with potential for further optimization. Estimated gravity recoveries are 50 per cent.

The results of the bulk sample testing to date (which does not include final refining of gold) are compared in the accompanying table with the results of delineation drilling which intersect the respective bulk sample zones.

                                          WLB2        F2 core  
 
Delineation drilling weighted average 5.8 g/t gold  9.1 g/t gold
Milled bulk sample testing results    7.1 g/t gold  8.2 g/t gold

Note: Delineation drilling weighted averages utilize a cap of 
270 g/t gold as utilized in the AMC resource estimates and are 
diluted by 17.9 per cent (AMC used 17.9-per-cent dilution 
outside the nominal two m mining width in its PEA).

Although the bulk sampling is located in part of the deposit that is lower grade than the overall resource average grade, it successfully confirms that the capped, diluted delineation drilling weighted average grade in this area is a reasonable determinant of recovered grade.

Tailings management facility

The tailings management facility (TMF) design incorporates engineered features to manage the chemical and physical stability of the deposited tailings in accordance with current best-in-class practices. Approximately 55 per cent of the tailings will be converted to paste fill and deposited underground to minimize the amount of tailings that will be deposited on surface and also to provide a suitable backfill for the underground mine. The remaining tailings will be thickened to greater than 75 per cent solids prior to deposition in the TMF, which has a capacity of approximately 25 years (based on a deposition rate of 190,000 tonnes of tailings per year following the ramp-up period) with the potential for optimization and expansion.

Capital costs

The initial capital costs (including a 30-per-cent contingency or approximately $50-million) are estimated to be $214-million. Sustaining capital and capital development for the life-of-mine average $4.3-million/year and $6.1-million/year respectively and would be derived from cash flows.

Operating costs

The average life-of-mine costs shown in the accompanying table are projected for the operating phase of the project.

            Items            Cost per processed tonne ($) Cost per recovered ounce ($)

Mining cost                              189                         458             
Processing and refining costs             22                          53             
G&A                                       2                           4              
Reclamation                               1                           2              
Total                                    214                         519             

*Numbers may not add up due to rounding.

Closure and rehabilitation costs

Rehabilitation measures have been designed to ensure the long-term physical and chemical stability of the site in accordance with Ontario's closure plan approval process. The rehabilitation measures will return the site to a productive land use that will not require long-term care and maintenance. The rehabilitation cost is estimated to be approximately $6-million in total.

                                         SENSITIVITY ANALYSIS 

                 Net cash flow $M   NPV (5%)$M    IRR       Payback years --   Payback years -- 
                   (NPV (0%) $M)                             project start     production start

Au = $1,100/oz          739             433       28%            5.3                  3.3              
Au = $1,500/oz        1,482             933       48%            4.0                  2.0              
Au = $900/oz            368             183       16%            7.5                  5.5              

Resource estimation methodology

AMC prepared updated resource estimates which utilized the block model approach with Datamine software and included the results from all drilling carried out on the project by Rubicon up to Feb. 28, 2011. The estimates are in situ and undiluted.

Constrained wireframes for the mineralized domains were created by AMC using a 0.1 g/t Au threshold which was locally further expanded to incorporate all significant mineralized zones. A total of 10 mineralized domains were created and utilized for the resource estimation. Sample composite length of one metre was used and grades were capped at 270 g/t Au after compositing (a 270 g/t Au cap was selected based on cumulative frequency plot analysis).

The block model parameters are as shown in the accompanying table.

      Item            Dimensions      Samples used (minimum and maximum)

Parent block size   2 X 8 X 12 metres                            
Search ellipse 1   8 X 24 X 36 metres          3 and 10         
Search ellipse 2  16 X 48 X 72 metres          1 and 10         
Search ellipse 3 24 X 72 X 108 metres*         1 and 10         

* Compares with block model validation figures in 
previous NI 43-101 resource estimate published on 
March 31, 2011

Bulk density used was 2.90 tonnes per cubic metre and the estimation method was inverse distance cubed.

The resource is constrained by the base of overburden at surface, and no allowance is made for any crown pillar. There is no lower elevation constraint to the estimate. The cut-off applied to the resource is five g/t Au which is the same as used in previous estimates.

Permitting and continuing consultations

The company has all material permits in hand required for the development and construction stage for potential production, except for the following. The company intends to resubmit the closure plan as soon as practicable. The company expects to receive approval of the final three material permits, the Consolidated Amendment to Air Certificate of Air Approval 9500-7NGTTC, the amendment to the Permit to Take Water 2342-7LWRQU and the new Industrial Sewage Certificate of Approval before the end of third quarter 2011. The Canadian Environmental Assessment Agency has confirmed that the project does not involve a trigger for a federal environmental assessment.

The company is continuing its consultations with first nations and the Metis Nation of Ontario.

Preparation of PEA

The PEA has been prepared by AMC (all sections except metallurgy) and Soutex (metallurgy). AMC is an international geology and mining engineering consultancy group with extensive experience in resource estimation, mining studies and provision of assistance to mining development projects and operating mines. Soutex is a Canadian-based consulting firm specializing in mineral process evaluation. An NI 43-101 technical report for the PEA, including a new resource statement, will be filed on SEDAR within 45 days of the date of this news release.

Qualified persons

Phoenix project exploration, drill work programs and all data forming the basis of this release were supervised and verified by Terry Bursey, PGeo, regional manager for Rubicon and a qualified person under the definition of NI 43-101. Drill core assays were conducted on sawn NQ-sized half core sections. The saw blade is routinely cleaned between samples when visible gold is noted during logging and sampling of the drill core. All assays were conducted by SGS Minerals Services using standard fire assay on a 50-gram sample with a gravimetric finish procedure. Standards, blanks and check assays were included at regular intervals in each sample batch. Check assays on 5 per cent of samples are carried out at a third party independent laboratory. Gold standards were prepared by CDN Resource Laboratories Ltd.

The content of this news release, other than that pertaining to bulk sampling, metallurgy and processing, has been read and approved by Bert Smith, PEng, and Mr. Shannon, PGeo, respectively consulting mining engineer and consulting geologist of AMC, and independent qualified persons as defined by NI 43-101. Exploration drill programs and all data forming the basis of the inferred and indicated resource estimate described in this release were supervised and verified by Terry Bursey, PGeo, regional manager for Rubicon and a qualified person as defined by NI 43-101. The inferred and indicated resource estimation, including the block modelling, was carried out by Ms. Nussipakynova, PGeo, and Ms. Pitman, PGeo, who verified all data received from Rubicon in connection with same. Mr. Shannon, PGeo, supervised the resource estimation process. All are consulting geologists of AMC and independent qualified persons as defined by NI 43-101. The mill sample testing results were prepared by Swastika Laboratories. The bulk sample process was conducted under the supervision of Eric Hinton, PEng, project manager for Rubicon and qualified person as defined by NI 43-101 and the laboratory work and mill processing was supervised by Pierre Roy, PEng, of Soutex (Quebec City, Que.), who is an independent qualified person as defined by NI 43-101.

The PEA has been prepared by AMC with metallurgical and processing contributions from Soutex. Individual contributing authors are Mr. Smith, PEng, and Mr. Shannon, PGeo, of AMC, and S. Caron, Ing, of Soutex. All are independent qualified persons as defined by NI 43-101.

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