WHITE ROCK, BRITISH COLUMBIA--(Marketwire - Aug. 29, 2012) -
NOT FOR DISTRIBUTION IN THE UNITED STATES.
New Carolin Gold Corp. (TSX VENTURE:LAD) is pleased to report that recent metallurgical test results at SGS Canada Ltd. have demonstrated that high gold recoveries are possible using pressure oxidation (POX) pre-treatment on a gold flotation concentrate followed by carbon in leach (CIL) gold recovery.
The gold recovery achieved in POX-CIL testing of flotation concentrate is 96.3%. The overall recovery of gold by flotation-pressure oxidation-cyanidation combined with cyanidation of the flotation tailing is 94.5%.
The current results have demonstrated that very high gold recoveries are possible using a combination of conventional flotation, pressure oxidation and cyanidation. Additional test work may include two other processes, namely BIOX and Albion, which have capabilities of achieving high gold recoveries.
This test work was conducted to support the development of a preliminary economic assessment for the former producing Carolin Mine and the McMaster Zone.
Detailed presentation of results follows in the body of this press release.
Metallurgical Testing and Results
A metallurgical sample, with head grade of the composite assaying 3.70 g/t gold, 1.59%S, 0.052%As and 0.55 g/t silver was provided to SGS Canada Ltd. for gold recovery testing. The sample was core from the McMaster Zone which assayed 3.96 g/t gold over 27.6 metres [DDH 32 - 09, from 32.4 to 60.0 metres, see press release January 12, 2010]. Mineralization of the McMaster Zone is similar to that of the Carolin Mine. There is no core available from the historical drilling of the Carolin Mine.
Flotation, Pressure Oxidation and Cyanidation:
A significant amount of gold is locked in refractory sulfide minerals (predominantly pyrite with arsenopyrite). Flotation may be used to produce a refractory sulfide - gold concentrate. Refractory sulfide ores or concentrates (if produced) are generally treated by pre-oxidation (pressure oxidation, biological oxidation, or roasting) prior to recovery of gold by cyanidation.
Pressure oxidation is a standard technology for pre-treatment of refractory gold ores and concentrates to increase the recovery of gold. It is used routinely at operations all over the world including by Goldcorp at Red Lake and by Barrick Gold in Nevada.
In this work, the flotation concentrate was pressure oxidized under industry-standard conditions followed by carbon-in-leach cyanidation of the oxidation residue. The concentrate contained sufficient sulphur to meet the heat requirements of the pressure oxidation. Each of the individual concentrates is autothermal with respect to sulfur grade for pressure oxidation (i.e. no supplemental heat would be required for normal autoclave operation). The results are summarized below:
- Flotation of the sample produced a rougher concentrate containing 39.7 g/t Au, 7.21 g/t Ag and 16.7%S at a gold recovery of 91.3%.
- The pressure oxidation of the concentrate yielded an average sulphide oxidation of 97.2%.
- The cyanidation of the pressure oxidation residue recovered 96.3% of the gold under carbon-in-leach conditions.
- The cyanidation of the flotation tailing recovered an additional 75.7% of the gold present.
- Combining flotation (91.3% recovery) and POX-CIL (96.3% recovery) yields an overall recovery of 87.9%. (96.3% of 91.3%)
- By adding the recovery by cyanidation of the flotation tail (75.7% of (100.0 - 91.3%)) = 6.6 + 87.9, the overall recovery of gold is 94.5%.
Dr. David Dreisinger, P.Eng., F.C.I.M., F.C.A.E., is the Qualified Person (NI 43-101) who supervised the preparation of the technical information in this news release. Dr. Dreisinger is Professor and Chairholder, Industrial Research Chair in Hydrometallurgy at the University of British Columbia (Vancouver, Canada) and consults to the worldwide metallurgical industry through Dreisinger Consulting Inc.
The Company's CEO, Bruce Downing, stated, "The results of the POX and conventional flotation testing confirm that the gold resource is not difficult to treat from a metallurgical standpoint and have proven capable of achieving high gold recoveries from the concentrates."
About New Carolin Gold Corp.
New Carolin Gold is a Canadian-based junior mineral exploration and development company engaged in the acquisition, exploration, evaluation and development of 144 sq kms of contiguous mineral claims, collectively known as the Ladner Gold Project, located along the prospective and under-explored Coquihalla Gold Belt located in southeastern British Columbia, which is host to several historic small gold producers including the Carolin Mine, Emancipation Mine, Pipestem Mine and numerous gold prospects.
For further information please visit the website at www.newcarolingold.com.
ON BEHALF OF THE BOARD OF DIRECTORS
Bruce W. Downing, M.Sc., P.Geo, Hon.FEC, President & Chief Executive Officer
We seek Safe Harbor.
Caution concerning forward-looking information
This news release may contain forward-looking statements that are based on the Company's expectations, estimates and projections regarding its business and the economic environment in which it operates. These statements are not guarantees of future performance and involve risks and uncertainties that are difficult to control or predict. Therefore, actual outcomes and results may differ materially from those expressed in these forward-looking statements and readers should not place undue reliance on such statements. Statements speak only as of the date on which they are made, and the Company undertakes no obligation to update them publicly to reflect new information or the occurrence of future events or circumstances, unless otherwise required to do so by law.
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