Roca Mines Inc.
TSX VENTURE : ROK

Roca Mines Inc.

August 31, 2005 16:05 ET

Roca Mines Inc.: MAX Molybdenum Project-Metallurgical Test Results

VANCOUVER, BRITISH COLUMBIA--(CCNMatthews - Aug. 31, 2005) - Roca Mines Inc. ("Roca" or the "Company") (TSX VENTURE:ROK) announces that it has received final results from metallurgical test work for the MAX Molybdenum Project. The results demonstrate the potential to produce a premium molybdenite concentrate at recovery rates in excess of 96 percent.

Metallurgical samples were collected from the upper adit-level of the HG (High-Grade) Zone within the MAX Molybdenum deposit and were combined to produce composite head grades of approximately 1.5% molybdenite (MoS2). The test work, which included lock-cycle testing, indicates that simple flotation is expected to produce a readily saleable, premium quality molybdenite concentrate. The test process included primary grinding to approximately 90 microns, rougher flotation, concentrate re-grinding and three stages of flotation cleaning. The process design criteria generally follow that defined by previous operators in the early 1980's but demonstrate better overall recoveries. The results will assist the Company in the development and design of milling operations for its proposed small mine plan.

In addition to the metallurgical test work above, an assessment of the quality of final molybdenite concentrates produced was also carried out. Assaying of the product demonstrates that it readily achieves the quality defined by typical molybdenite concentrate buyer specifications. For example, assayed levels for impurities such as copper (Cu), lead (Pb) and zinc (Zn), are demonstrated to be significantly lower than the limits specified by buyers and the MAX product could achieve a premium price at market.



Final Molybdenum Concentrate Quality

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Locked Cycle Average Assays
------------------------------------------------------------
As Bi Ca Cu P Pb Sb W Zn
(ppm) (ppm) (%) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)
------------------------------------------------------------
130 19 0.04 158 less 58 44 10 36
than
10
------------------------------------------------------------
Notes: 1. All test work supervised by International Metallurgical
and Environmental Inc.
2. All assay results by ECO TECH Laboratory Ltd.


Typical Buyer Specification for Molybdenite Concentrate Quality

------------------------------------------------------------
Maximum Allowable Limits
------------------------------------------------------------
As Bi Ca Cu P Pb Sb W Zn
(ppm) (ppm) (%) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)
------------------------------------------------------------
500 500 .5 5000 500 500 500 500 500
------------------------------------------------------------
Notes: "ppm" equals Parts per Million, (for example, 1.0 PPM
equals .0001%)


Mr. Jeff Austin, P.Eng. of International Metallurgical and Environmental Inc. is the NI 43-101 Qualified Person supervising the metallurgical testing program. The assay component of the program includes quality control procedures, including the use of blanks and duplicates in addition to internal quality control at the assay laboratory, Eco Tech Laboratory of Kamloops, BC, an accredited laboratory. Mr. Scott Broughton, P.Eng. is the NI 43-101 Qualified Person responsible for the preparation of this news release.

Roca's wholly-owned subsidiary, FortyTwo Metals Inc. (www.fortytwometals.com) is currently awaiting comment on its British Columbia Small Mines Permit application for development of the project.

ROCA MINES INC.

Scott E. Broughton, P.Eng. - President and CEO

The TSX Venture Exchange does not accept responsibility for the adequacy or accuracy of this release.

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