Rokmaster Resources's Recent Metallurgical Tests Achieve 99.3% Oxidation and 96% Gold Recovery at Revel Ridge
Rokmaster's recent test program is part of the ongoing assessment of metal recovery technologies to refine and optimize the metallurgical responses of the Revel Ridge Main Zone ("RRMZ") mineralization.
Previous bulk samples were shipped to Base Metallurgical Labs in Kamloops, B.C., and composited using the same procedures and recipe as formerly used to remake the JL1 composite test sample.
The 2021 JL1 Composite was used to successfully test the new gravity-flotation flowsheet without using any preconcentration. Gravity concentrate and sulphide concentrate were then combined to create the pressure oxidation ("POX") feed, on which the latest results are below.
Recent POX tests on the upgraded grav-float concentrate are now achieving 96.0 - 99.3% oxidation. The POX parameters to achieve these high levels of oxidation, although continuing to be optimised, are:
- Pre-acidification
-
- Temperature: 30-60°C
- Target pH: 1.0-2.2
- Retention time: 15 mins - 1 hour
- POX
-
- Feed Pulp Density: 10-15% solids (w/w)
- Temperature: 220°C
- O2 Over Pressure: 100psig (6.89 bar)
- Retention time: 60-120mins
- Hot Curing
-
- Temperature: 90-100°C
- Retention time: 4 hours
The POX tests are indicating that oxygen transfer is a key consideration for this mineralization, so pulp density and residence time optimizations are ongoing. Mineralogy is also being undertaken to more fully understand the changes through the process.
Leaching of these oxidized concentrates are achieving gold recoveries over 96.0%. Test work is now focussing on optimising the leach parameters, increasing overall recoveries, and other flowsheet alternatives such as the Albion ProcessTM.
John Mirko, President and CEO of Rokmaster stated:
"We are excited about these metallurgical developments, the decreased mass pulls, increased gold concentrate grades, and pressure oxidation parameters being refined with high leach recoveries. We would like to thank those metallurgists for continuing to persevere and achieve such excellent results. Rokmaster will now optimise this flowsheet and undertake variability testing this year."
The technical information in this news release has been prepared in accordance with Canadian regulatory requirements has been reviewed and approved by Mr. Stacy Freudigmann, P.Eng. F.AusIMM., who is a Qualified Person as set out in National Instrument 43-101 and is independent of Rokmaster.
On Behalf of the Board of Directors of
John Mirko,
President & Chief Executive Officer.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term in defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this press release.
About Rokmaster
Rokmaster controls a portfolio of three significant exploration and development projects all of which are located in southern British Columbia in regions of excellent infrastructure. The three projects include:
- Revel Ridge. Rokmaster is currently conducting an underground drill program at the Revel Ridge Project located in southeastern British Columbia 35 km's north of the City of Revelstoke. Revel Ridge is host to a high-grade gold and polymetallic orogenic sulphide deposit which has been the subject of a PEA Technical Report dated December 8, 2020.
- Big Copper. Rokmaster controls the Big Copper Property in the Kimberley area of southern British Columbia. Big Copper is a high-grade copper-silver occurrence hosted in mid-Proterozoic rocks. Copper-silver mineralization has been traced for 4.5 km along strike and is exposed in a series of adits and trenches over approximately 500 m of vertical relief. Big Copper likely belongs to a class of stratabound replacement copper-silver deposits hosted within mid - Proterozoic quartzitic sediments. The style and stratigraphic setting of mineralization at Big Copper may be analogous to similar stratabound silver-copper deposits in NW Montana, e.g., the Troy Mine (a significant past producer of copper and silver) and Hecla's Montanore pre-development project, with, 112 million tonnes Inferred at 54.8 g/t Ag and 0.7% Cu*. (Hecla, 2020 Annual Report, Pg. 119. www.hecla-mining.com).2
Footnote (1). The qualified person has been unable to verify this inferred resource.
- Duncan Lake Zinc. Duncan is a carbonate hosted silver-lead-zinc deposit located near Duncan Lake in southern British Columbia. The deposit is hosted within a Cambrian age Badshot Limestone which also hosts Zn-Pb-Ag mineralization at Teck's recently producing Pend D'Oreille Mine as well as past producers including the Blue Bell Mine, Reeves MacDonald Mine, Jersey-Emerald and HB mines. Mineralization at Duncan Lake forms in the crest and limbs of the regional scale Duncan Lake anticline, where strong zinc-lead +/- silver mineralization has been traced by surface and underground drilling for approximately 2,500 m. At Duncan Lake, Rokmaster will be targeting > 30 Mt of >10% Zn+Pb+Ag. Historical background and a geological synthesis of the Duncan Lake deposit is provided in a NI 43-101 report by Lane, B., 2018: Technical Report on the Duncan Lake Project.
CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS: This news release may contain forward-looking information within the meaning of applicable securities laws ("forward-looking statements"). Forward-looking statements are statements that are not historical facts and are generally, but not always, identified by the words "expects," "plans," "anticipates," "believes," "intends," "estimates," 'projects," "potential" and similar expressions, or that events or conditions "will," "would," "may," "could" or "should" occur. These forward-looking statements are subject to a variety of risks and uncertainties which could cause actual events or results to differ materially from those reflected in the forward-looking statements, including, without limitation: risks related to fluctuations in metal prices; uncertainties related to raising sufficient financing to fund the planned work in a timely manner and on acceptable terms; changes in planned work resulting from weather, logistical, technical or other factors; the possibility that results of work will not fulfill expectations and realize the perceived potential of the Company's properties; risk of accidents, equipment breakdowns and labour disputes or other unanticipated difficulties or interruptions; the possibility of cost overruns or unanticipated expenses in the work program; the risk of environmental contamination or damage resulting from Rokmaster's operations and other risks and uncertainties. Any forward-looking statement speaks only as of the date it is made and, except as may be required by applicable securities laws, the Company disclaims any intent or obligation to update any forward-looking statement, whether as a result of new information, future events or results or otherwise.
SOURCE Rokmaster Resources Corp.
Contact
For more information please contact Mr. John Mirko, President & CEO of Rokmaster Resources Corp., jmirko@rokmaster.com, Ph. 1-604-290-4647 or by website: www.rokmaster.com; For shareholder information please contact: Mike Kordysz, mkordysz@rokmaster.com,Ph. +1 (604) 319-3171