Jinshan Reports Positive Metallurgical Results From Its Dadiangou Gold Project, China
Tue Jul 22, 8:19 AMVANCOUVER, BRITISH COLUMBIA--(Marketwire - July 22, 2008) - Jinshan Gold Mines Inc. (TSX: JIN.TO) is pleased to report results from metallurgical testwork on two samples of sulphide mineralization from its Dadiangou Gold Project in Gansu province, China. Whole ore cyanidation tests returned gold recoveries generally in excess of 90% from the two samples. In addition, simple gravity separation was able to recover 28% to 51% of the gold prior to cyanidation of the gravity concentrate tails. Jinshan will now proceed with additional testing on a wider range of crush and grind sizes, and column testing, in order to more fully evaluate the processing options at Dadiangou.
"We are pleased to confirm that the sulphide portions of the Dadiangou deposit leach readily," said Jinshan's Vice President of Exploration, Keith Patterson. "Further work will be needed before a final process flow sheet can be determined but the first step of confirming that the gold can be extracted through simple cyanide leaching is now complete." Two bulk samples of fresh sulphide mineralization were collected from underground adits within the central portion of the Dadiangou Main Zone and shipped to METCON Research in Tucson, Arizona. Head grades of the two samples were 1.43 grams per tonne (g/t) and 2.54 g/t gold and are considered representative of the known mineralization within the Dadiangou Main Zone. The samples were crushed, split into individual test charges, and then ground to the appropriate size for each test. Testwork was designed to investigate the cyanide leach and gravity concentration characteristics of the mineralization when ground to 80% passing (P80) through 150, 200, and 400 mesh (105, 74, and 37 microns). Whole ore leach tests were conducted by bottle roll testing at 45% solids for 72 hours. Pulp aeration was conducted for six hours prior to the leach tests. Results of these tests are shown in Table 1 below. Of interest is that all grind sizes tested reported good gold recoveries indicating that the optimal grind size may be coarser than the sizes tested.
Table 1: Results of whole ore leach tests.
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Reagent
Consumption
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NaCN CaO Leach Time Extraction
Grind Size (P80) (kg/t) (kg/t) (hours) (% Au)
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DDG-01 (1.43 g/t Au)
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24 85.7
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105 microns 0.14 0.53 48 88.8
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72 91.0
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24 86.6
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74 microns 0.38 0.62 48 92.4
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72 90.2
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24 87.5
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37 microns 0.40 0.77 48 90.7
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72 86.2
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DDG-02 (2.54 g/t Au)
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24 94.8
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105 microns 0.29 0.57 48 98.9
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72 96.5
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24 92.4
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74 microns 0.32 0.70 48 96.1
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72 93.4
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24 74.5
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37 microns 0.46 0.87 48 77.1
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72 93.2
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Gravity concentration testwork was conducted on 10 kilogram test charges using a Falcon concentrator. Both samples DDG-01 and DDG-02 showed significant amounts of coarse gold recoverable by simple gravity methods. Table 2 shows complete results of the gravity testwork.
Table 2: Results of gravity concentration tests.
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Weight Assay Recovery
Product (%) (g/t Au) (% Au)
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DDG-01 (1.43 g/t Au)
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Cleaner Gravity Concentrate 0.5 77.0 27.6
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Cleaner Gravity Concentrate Tails 36.8 1.0 26.1
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Rougher Gravity Tails 62.7 1.1 46.3
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DDG-02 (2.54 g/t Au)
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Cleaner Gravity Concentrate 1.6 72.5 50.9
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Cleaner Gravity Concentrate Tails 37.6 1.4 22.0
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Rougher Gravity Tails 60.8 1.0 27.1
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The Dadiangou gold system is located in the central part of China in southern Gansu Province within the prolific Qinling Fold Belt. The license covers approximately 15 square kilometres and is owned by the Northwest Industrial Nuclear Economic Technical Corp. (part of the Shaanxi Nuclear Geology Bureau of China). The joint-venture agreement with the Northwest Industrial Nuclear Economic Technical Company (the Chinese partner) allows Jinshan to earn up to 80% by conducting property expenditures and making payments to the Chinese partner. The Chinese partner can participate at a 20% level for development and capital expenditures, or be diluted. The Qualified Person as defined by National Instrument 43-101 who is overseeing all aspects of the Dadiangou Project is Mr. Keith Patterson M.Sc., P.Geo., Jinshan's Vice President of Exploration. Mr. Patterson has supervised the preparation of scientific and technical information contained in this release and consulted metallurgical experts to verify the validity of the results. About Jinshan Jinshan is a Canadian mining company focused on gold production and acquisitions in China. The company began producing gold at the CSH Mine in July 2007 and is actively advancing its portfolio of gold exploration properties in China. Jinshan's shares are listed on the Toronto stock exchange under the symbol JIN. China National Gold, a Chinese state-owned enterprise and the largest gold producer in China owns approximately 42% of Jinshan's shares. Forward-Looking Statements: Statements in this release that are forward-looking statements, including the planned future metallurgical testwork, future recovery of gold from the Dadiangou project, and the potential to grow Dadiangou into a bulk tonnage gold deposit are subject to various risks and uncertainties concerning the specific factors disclosed under the heading "Risk Factors" and elsewhere in the company's MD&A, financial statements and other periodic filings with Canadian securities regulators. Such information contained herein represents management's best judgment as of the date hereof based on information currently available. When used in this document, words such as "could", "planning", "estimate", "expect", "intend", "may", "potential", "should", and other similar expressions are forward looking statements. The company does not assume the obligation to update any forward-looking statement. ContactsDeanna Kress Jinshan Gold Mines Inc. - Investors
(604) 609-0598
Email: info@jinshanmines.com
Website: www.jinshanmines.com
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