PolyMet Simplifies Metallurgical Process at NorthMet Project

HOYT LAKES, MINNESOTA -- (Marketwire) -- 02/02/11 -- PolyMet Mining Corp. (TSX: POM)(NYSE Amex: PLM) ('PolyMet' or the 'Company') announced today that it has simplified the proposed metallurgical process at its NorthMet copper-nickel-precious metals project located in the established Mesabi mining district in northeastern Minnesota.

PolyMet now plans to build the project in two phases:

--  Phase I: produce and market concentrates containing copper, nickel,
    cobalt and precious metals
--  Phase II: process the nickel concentrate through a single autoclave,
    resulting in production and sale of high grade copper concentrate, value
    added nickel-cobalt hydroxide, and precious metals precipitate products.

Previous plans included a second autoclave and a copper solvent extraction/electro-wining ('SX-EW') circuit to produce copper metal along with value added nickel-cobalt hydroxide and precious metals precipitate products.

The changes reflect continued metallurgical process and other project improvements as well as improved environmental controls that are being incorporated into the Supplemental Draft Environmental Impact Statement ('SDEIS'). The analysis is based on likely metal market conditions. The advantages, compared with the earlier plan, include a better return on capital investment, reduced financial risk, lower energy consumption, and reduced waste disposal and emissions at site.

PolyMet's last formal update of project scope and costs was in May 2008 - when total project costs for the two-autoclave plus SX-EW circuit were estimated to be $602 million. Of that total, approximately $127 million was attributed to the second autoclave and the copper circuit.

PolyMet plans to provide a detailed project update when the project development plans now being analyzed in the SDEIS are finalized. This detailed project update will include revised mine plans, process and project improvements, and will incorporate the latest environmental controls.

'The changes to the project improve the overall economics of the project while reducing environmental impacts. The SDEIS will incorporate these changes and is anticipated to be competed this summer,' stated PolyMet's President and CEO Joe Scipioni. 'The project will create approximately 360 long-term, well paid jobs compared to the project's original estimate of 400 workers,' Scipioni added.

About PolyMet

PolyMet Mining Corp. (www.polymetmining.com) is a publicly-traded mine development company that controls 100% of the NorthMet copper-nickel-precious metals ore body through a long-term lease and owns 100% of the Erie Plant, a large processing facility located approximately six miles from the ore body in the established mining district of the Mesabi Range in northeastern Minnesota. PolyMet Mining Corp. has completed its Definitive Feasibility Study and is seeking environmental and operating permits to enable it to commence production. The NorthMet project is expected to require more than one-and-a-quarter million hours of construction labor and create approximately 360 long-term jobs, a level of activity that will have a significant multiplier effect in the local economy.

POLYMET MINING CORP.

Joe Scipioni, CEO

This news release contains certain forward-looking statements concerning anticipated developments in PolyMet's operations in the future. Forward-looking statements are frequently, but not always, identified by words such as 'expects', 'anticipates', 'believes', 'intends', 'estimates', 'potential', 'possible', 'projects', 'plans', and similar expressions, or statements that events, conditions or results 'will', 'may', 'could', or 'should' occur or be achieved or their negatives or other comparable words. These forward-looking statements may include statements regarding our beliefs related to the expected proceeds and closing of the registered direct offering, exploration results and budgets, reserve estimates, mineral resource estimates, work programs, capital expenditures, actions by government authorities, including changes in government regulation, the market price of natural resources, costs, or other statements that are not a statement of fact. Forward-looking statements address future events and conditions and therefore involve inherent risks and uncertainties. Actual results may differ materially from those in the forward-looking statements due to risks facing PolyMet or due to actual facts differing from the assumptions underlying its predictions. PolyMet's forward-looking statements are based on the beliefs, expectations and opinions of management on the date the statements are made, and PolyMet does not assume any obligation to update forward-looking statements if circumstances or management's beliefs, expectations and opinions should change.

Specific reference is made to PolyMet's most recent Annual Report on Form 20-F for the fiscal year ended January 31, 2010 and in our other filings with Canadian securities authorities and the Securities and Exchange Commission, including our Report on Form 6-K providing information with respect to our operations for the nine months ended October 31, 2010 for a discussion of some of the risk factors and other considerations underlying forward-looking statements.

The TSX has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.

Contacts:

PolyMet Mining Corp. - Corporate

Douglas Newby

Chief Financial Officer

1 (212) 867-1834
dnewby@polymetmining.com


PolyMet Mining Corp. - Media

LaTisha Gietzen

VP Public, Gov't & Environmental Affairs

1 (218) 225-4417
lgietzen@polymetmining.com


PolyMet Mining Corp. - Investors

Crystal Agresti

1 (845) 742-8153
cagresti@polymetmining.com


PolyMet Mining Corp. - Investors

Alex Macdougall

1 (226) 663-3000
amacdougall@polymetmining.com
www.polymetmining.com