Metallurgical Testing of New Polaris Ores Improves Gold Recoveries to 95%
Canarc Resource Corp. (CCM:TSX and CRCUF:OTC-BB) announces that metallurgical testing of gold ores from the New Polaris project in northwestern British Columbia has improved gold recoveries to the 95% level.
Initial optimization work focused on grinding and flotation to liberate and concentrate the sulfide minerals containing gold. By grinding the ore to 95% minus 200 mesh and then running it through 3 cycles of rougher flotation with conditioning, 96.6% of the gold in the ore reported to the final concentrate, which graded 92 gpt gold.
This gold concentrate was then subjected to testing for gold extraction by comparing pressure oxidation and bio-oxidation. Batch acid pressure oxidation (autoclave) tests showed that 100% oxidation of the sulphide minerals could be achieved within 60 minutes, showing that New Polaris ores are very amenable to the autoclaving process.
The oxidized concentrates were then treated by cyanide leaching to achieve a 98.5% rate of gold extraction within 24 hours from concentrate, for an over-all gold recovery from ore of 95.1% a substantial increase over previous testwork. Bio-oxidation tests achieved up to a 93% extraction rate of gold from concentrate, for an overall gold recovery from ore of 88.9%.
In summary, metallurgical testing has successfully increased gold recoveries from New Polaris ores to the 95% level, by optimizing the grinding, autoclaving and leaching processes. Bio-oxidation is still a possibility, even though it returned lower recoveries compared to autoclaving, because the anticipated capital costs are lower.
However, the more likely metallurgical alternate now under consideration is the shipping of gold concentrates from the New Polaris minesite to an existing “third party” autoclave elsewhere in North America. Additional detailed metallurgical testwork will likely be needed for any feasibility study on New Polaris.
Canarc Resource Corp. is a growth-oriented, gold exploration and mining company listed on the TSX (symbol CCM) and the OTC-BB (symbol CRCUF). The Company’s principal assets are its 100% interest in the New Polaris gold deposit in British Columbia and its 80% option on the Benzdorp gold property in Suriname. Major shareholders include Barrick Gold Corp. and Kinross Gold Corp.
On Behalf of the Board of Directors CANARC RESOURCE CORP.
Bradford J. Cooke President and C.E.O.
For more information, please contact Gregg Wilson at tel: (604) 685-9700, Toll Free: 1-877-684-9700 fax: (604) 685-9744, email [email protected] or visit our website, www.canarc.net. The TSX Exchange has neither approved nor disapproved the contents of this news release.