Update on Colombia

RNS Number : 6195U

Red Rock Resources plc

19 October 2010

 



RED ROCK RESOURCES PLC

Update on Colombia

Dated: 19 October 2010

Red Rock Resources plc ("Red Rock" or the "Company"), the gold mining and exploration company with projects in Kenya and Colombia, and interests in steel feed  and uranium, reports the results of metallurgical testwork carried out on ore from the El Limon mine in Colombia.

·    Sampled gold grade of 45.3 grams per tonne

·    21% of gold recovered by gravity concentration, grading 6603 grams per tonne gold

·    97% of gold recovered in 24 hours in whole ore leach tests

Results from metallurgical testwork on ore taken from the El Limon mine have been received from G&T Metallurgical Services Limited of Kamloops, Canada.

Three bagged samples totalling 16.6kg of ore were combined to form a master composite.

The chemical composition of the master composite was determined using standard analytical techniques, and showed a chemical content of 45.3 grams per tonne gold, 72 grams per tonne silver, and 0.01% copper.

A gravity concentration test was conducted on the sample ground to about 143μm K_80.  The gravity concentration was a two step process, with a Knelson concentrator followed by hand-panning. About 21 per cent of the feed gold was recovered into the pan concentrate.

Three 500g charges of the master concentrate were ground to three primary grind sizes between 157μm K₈₀ and 68μm K₈₀.  Forty eight hour cyanidation bottle roll tests were conducted on each ground sample charge, with sodium cyanide concentration at 1,000 ppm and the cyanidation pH controlled at 11.0 using lime.

The three tests produced similar results, with 97 per cent of the gold feed extracted to solution and leaching effectively complete after twenty-four hours. It was determined that over the range tested primary grind size does not affect gold leach performance.

Cyanide consumption ranged between 1.2 and 1.9 kg/tonne while lime consumption averaged approximately 0.5 kg/tonne.

This preliminary suite of metallurgical tests indicated that the gold present in this sample responded quite well to gravity concentration techniques. Whole ore leach tests on the composite showed exceptional gold leaching kinetics.

The laboratory suggests that further optimisation testing should be considered as there may be some opportunity to increase primary grind size, as well as to reduce reagent consumption and maintain good gold extraction by reducing the leach time and target cyanide concentrations.

The Company notes that the gold grade reported from the sample is broadly consistent with historical evidence and with previous reports from the mine, including the Fischer-Watt Gold Company Inc.'s 10-KSB report to the Securities and Exchange Commission of the U.S. of 16^th May 1997, File Number 0-17386, pages 4-7

(http://www.secinfo.com/dV5ud.85v.htm#26g2). 

The technical information in this announcement has been reviewed and approved for release by Aralia Pojhan, Project Metallurgist at G&T Metallurgical Services Limited.  

Enquiries:

Andrew Bell	0207 402 4580 or 07766 474849	Red Rock Resources plc	Chairman
Sandra Spencer	0207 402 4580 or 07757 660 798	Red Rock Resources plc	Public and Investor Relations
Peter Trevelyan-Clark/ Ben Jeynes	020 7444 0800	Religare Capital Markets	Nominated Adviser
Nick Emerson	01483 413500	Simple Investments Ltd	Broker

Updates on the Company's activities are regularly posted on its website, www.rrrplc.com.

 

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