Hydromet Compatibility Of Ferguson Lake Massive Sulfides

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Contract Signed to Build & Operate Hydromet Mini-Pilot Plant




TORONTO, May 24, 2011 /CNW/ - Starfield Resources Inc. (TSX: SRU) (OTCBB: SRFDF) ("Starfield", "the Company") today announced
positive preliminary test results on the processing of Ferguson Lake
ore.




The hydrometallurgical technology being developed is engineered to
recover base metals from massive sulphides at the Company's Ferguson
Lake project in Nunavut in an environmentally friendly, cost effective
and energy efficient manner.




Testing has been performed by SGS Canada Inc. in Lakefield, Ontario.
Phase I testing, completed in the summer of 2010, successfully
demonstrated continuous operation of the oxidation and hydrolysis
sections of the hydrometallurgical process using a synthetic feed
(primary leach solution). Phase II testing began in the fall of 2010
and concluded successfully in April 2011, successfully demonstrating
the oxidation and hydrolysis sections using actual feed made from
Ferguson Lake massive sulphides.




Results from testing of the primary and secondary leach circuits show
recoveries of 97% copper, 96% nickel, and 88% cobalt from a bulk
sulphide concentrate produced from Ferguson Lake ore into the leach
solution. The remaining metals, including PGEs, were left in the leach
residue.




"These are excellent results, far better than any of us could have hoped
for at the outset of this last round of test work," said Andre
Douchane, President and CEO of Starfield. "We've now taken the next
step and contracted SGS to build and operate a mini-pilot plant at
their facilities in Lakefield."




Leach solution generated from the bulk Ferguson Lake concentrate was
used to successfully demonstrate stable, continuous, simultaneous
operation of the two enabling steps in the hydrometallurgical
technology, i.e. oxidation and hydrolysis. The solution from the
primary leach was continuously oxidized and the oxidized solution was
sent directly to continuous hydrolysis. Two campaigns of one week each
were run. The target oxidation level (80% of the ferrous iron in the
leach solution) was achieved and in both campaigns reached up to 90%.




The extent of hydrolysis achieved also substantially exceeded
expectations - the expected extent was about 30% per pass, compared to
just over 70% achieved, with the operation of the hydrolysis reactor
remaining stable.




The solution from the oxidation and hydrolysis campaigns was used in a
continuous secondary leaching campaign, and the solution from the
secondary leach was re-oxidized in a secondary oxidation step in which
97% to 98% of the ferrous iron was oxidized.




Targeted oxidation of the same material at 80% for a single pass was
achieved in 18 hours of residence time, with the oxidation level
increasing to as much as 90% in the subsequent 30 hours of residence
time.




Hydrolysis tests on synthetic solution altered its content to produce
from 20% to 26% hydrochloric acid. Higher acid levels in the range of
34% could be produced, but unacceptably high amounts of iron oxide were
generated as a by-product. Interim filtration of the solution was used
to remove iron oxide, along with acid washing of the same iron oxide to
reduce the residual chlorine to less than 1%. The overall efficiency
of the oxidation and hydrolysis circuits now approach 100%.




The mini-pilot plant is expected to be operational by early calendar
2012. Including operational testing and construction costs, it is
expected that the cost of the plant will be between $4.2 and $4.8
million, depending on how quickly the plant achieves continuously
efficient operation. The mini pilot plant will be of sufficient size
that a facility capable of processing up to 5,000 tonnes of Ferguson
Lake material per day could be engineered.


The technical information in this news release has been reviewed by Ray
Irwin, BSc, P.Geo, a Qualified Person in accordance with National
Instrument 43-101.




About Starfield

Starfield Resources Inc. is an advanced exploration and development
stage company. The Company's primary asset is its Ferguson Lake
nickel-copper-cobalt-platinum-palladium property in Nunavut, Canada.
Additional assets include a nickel-copper-cobalt-PGE-chrome project in
the Stillwater district of Montana with historic copper, nickel,
chromite resources (non NI 43-101 and not to be relied on); the
Moonlight copper project in California; and two gold properties
currently leased/joint ventured in Nevada.


Starfield has also funded the development of a novel, environmentally
friendly and energy efficient hydrometallurgical flow sheet to recover
metals from massive sulphides.


About SGS

The SGS Group is the global leader and innovator in inspection,
verification, testing and certification services. Founded in 1878, SGS
is recognized as the global benchmark in quality and integrity. With
more than 59,000 employees, SGS operates a network of over 1,000
offices and laboratories around the world.




Forward-Looking Statements

This news release may contain certain information that constitutes
forward-looking statements. Forward-looking statements are frequently
characterized by words such as "plan," "expect," "project," "intend,"
"believe," "anticipate" and other similar words, or statements that
certain events or conditions "may" or "will" occur. Forward-looking
statements are based on the opinions and estimates of management at the
date the statements are made, and are subject to a variety of risks and
uncertainties and other factors that could cause actual events or
results to differ materially from those projected in the
forward-looking statements. These factors include the inherent risks
involved in the exploration and development of mineral properties, the
uncertainties involved in interpreting drilling results and other
geological data, fluctuating metal prices and other factors described
above and in the Company's most recent annual information form under
the heading "Risk Factors" which has been filed electronically by means
of the Canadian Securities Administrators' website located at
sedar The Company disclaims any obligation to update or revise
any forward-looking statements if circumstances or management's
estimates or opinions should change. The reader is cautioned not to
place undue reliance on forward-looking statements.




For further information:

Andre J. Douchane President and CEO 416-860-0400 ext. 222 [email protected] Greg Van Staveren Chief Financial Officer 416-860-0400 ext. 223 [email protected] Investor Relations 416-860-0400 [email protected]
http://www.starfieldres.com/">www.starfieldres.com