High Desert Gold Corporation ("HDG" or the "Company") announces the results from the latest series of metallurgical tests designed to assess the recoverability of gold by bottle roll testing using cyanidation. These tests were also conducted to assess the possible variation of gold grades due to the presence of coarse gold, the so called "nugget effect". These tests were conducted on 47 samples collected from the RC chips from the 2012 drill program at the Grey Eagle and Jumbo targets and the trench at the Grey Eagle target at Gold Springs in Nevada and Utah. All samples had previously been analyzed by fire assay.
These metallurgical tests used a much larger sample size of 1 kilogram instead of the 30 gram sample size used for the previous fire assays on the original drill chips. The average metallurgical recovery for all gold samples tested was 92% (79%-98%) and the overall gold grades calculated from the metallurgical recoveries increased by an average of 15% over the original fire assays for values >0.2 g/t gold. Gold grades ranged from 0.043 gpt to 13.056 in the original results providing a broad range of values for the test work. Samples in this test came from drill holes GE-12-001, GE-12-002, J-12-004 and J-12-005 as well as the Grey Eagle trench.
Ralph Fitch, President and CEO stated that "This is important new information and compares well with our earlier metallurgical test from the Jumbo target (PR10-17, October 18, 2010) where the average recovery from 12 samples was 97% using a combination of gravity recovery and cyanidation. It is remarkable that we are discovering gold mineralization starting at surface at both the Grey Eagle and the Jumbo targets and that 90-95% of this gold mineralization is recoverable through cyanidation. The 10 samples from the Grey Eagle trench gave an average recovery of 95%. This trench averaged 1.54 g/t gold Eq over 56 metres (see HDG PR 12-20, Nov. 7, 2012). These high gold recoveries bode well for the economics of any future project. The significance of the larger one kilogram samples returning higher grades than the originally reported assays is that the reported fire assay grades are probably low due to "nugget effect". This being so we are looking into new assaying protocols that may be able to mitigate this issue going forward."
The one kilogram samples were ground to a powder (85% <200 mesh) then subjected to cyanidation for 72 hours, with gold assays taken at 24, 48 and 72 hours. The residue or tail was also assayed. The vast majority of the gold was recovered in the first 24 hours with only an additional 3% of the gold being recovered between 24 and 48 hours and little additional recovery between 48 and 72 hours, indicating rapid availability of the gold at the 200 mesh grain size. Recoveries were very uniform with only a slight increase in recovery with grade. Low grade material between 0.048 g/t and 0.2 g/t gold had an average recovery of 87% whereas material grading 0.2 g/t to 13 g/t had an average recovery of 93%.
Gold Springs is a 70/30 Joint Venture with Pilot Gold Inc. in which HDG holds a 70% interest and is the operator of the Joint Venture.
The Qualified Person on the Gold Springs property is Randall Moore, Executive Vice President of Exploration of High Desert Gold Corporation and he has reviewed and approved the content of this press release and has verified the data, including sampling, analytical and test data, included in this press release. The data has been reviewed for consistency and checked against the original assays for the same samples.
All technical information in this news release is obtained and reported under a quality assurance and quality control program. This program includes chain of custody protocols and systematic assaying of sample duplicates and commercially prepared standards and blanks for analytical reliability. All samples are collected under the supervision of Company geologists and transported directly to Inspectorate Laboratories in Reno, Nevada by Company personnel. The metallurgical tests and assays were performed in Reno, Nevada by Inspectorate Laboratories, an ISO 9001:2000 Certified laboratory. Gold was analyzed by fire assay of a 30 gram sample with an AA or gravimetric finish and by cyanidation of a one kg sample.
Source: http://www.highdesertgoldcorp.com/