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VANCOUVER, BRITISH COLUMBIA -- (Marketwire) -- 02/12/13 -- Orsa Ventures Corp. (TSX VENTURE: ORN) ("Orsa" or the "Company") is pleased to announce that its consultants, JDS Energy and Mining Inc., have completed a detailed review of metallurgical studies performed to date. The review confirms that oxide mineralization responds well to cyanidation. Column leach testing indicated recoveries between 74 to 88 percent on oxidized tuff and rhyolite. The inferred oxide resource as reported in last year's NI 43-101 report (dated February 2012) is shown in the table below:
--------------------------------------------------------------------------- Imperial Units Metric Units ------------------------------------------------------------------ Au AuArea/ Cutoff Tons Au Au Oz s Cutoff Tonnes Au Au Oz sMaterial (opt) (000) (opt) (000)(1) (g/t) (000) (g/t) (000)(1)---------------------------------------------------------------------------Total Oxide 0.006 70,710 0.018 1,297 0.21 64,148 0.63 1,297---------------------------------------------------------------------------Total Sulfide 0.017 51,036 0.030 1,551 0.58 46,300 1.04 1,551---------------------------------------------------------------------------Total Project n/a 121,746 0.023 2,848 n/a 110,448 0.80 2,848---------------------------------------------------------------------------
During the late 1980's metallurgical testing was done in support of pre-feasibility and feasibility studies for the owner, Quartz Mountain Gold Corporation ("QMGC"). The next and last major program was conducted by Pegasus Gold Corporation in 1990 and 1991 in support of a two year pre-feasibility study. All the metallurgical testing was performed by the Anaconda Research Lab (1985); Kappes/Cassiday and Associates (1985); Bateman Labs (1986-1988); and McClelland Labs (1988). Since 1991 no mineral processing and metallurgical testing has been carried out on the project.
All samples collected for these programs were analyzed using bottle roll, test columns, flotation tests, and bacterial oxidation tests to determine gold recovery using cyanidation techniques. Given the deposit type (low grade bulk tonnage), particular emphasis was placed on heap leach methods including cyanide extraction bottle roll and column tests.
In April 1988, Minproc (U.S.A.) Inc. completed a preliminary feasibility analysis of the Crone Hill and Quartz Butte deposits. In May 1988, QMGC retained Davy McKee Corporation to re-evaluate the metallurgical process and assay data. Between mid-September and late November 1988, 19 deep drill holes totaling 14,675 feet were completed within the Quartz Butte deposit to explore for high-grade feeder veins that could be located within the throat of the Quartz Butte dome.
From this drill program, ten larger samples were processed by bottle rolls and column leach tests utilizing 3/4" and 1 1/2" crushed material. The results from these tests led Davy McKee to the design of a split heap leach / milling flow sheet whereby the lower grade oxides would be heap leached at a -3/4 inch crush size and the higher grade oxides would be milled along with the sulfide ore. A feasibility study was completed in August of 1989 with generally positive conclusions.
