Rokmaster Solves Metallurgy at Revel Ridge, Achieves Overall Gold Recovery of 96.8%
VANCOUVER, June 1, 2022 - Rokmaster Resources Corp. (TSXV: RKR) (OTCQB: RKMSF) (FSE: 1RR1) ("Rokmaster" or "the Company") is pleased to announce the development of a high-recovery extraction process for gold, silver and other metals for the first time in the history of the Revel Ridge Project ("Revel Ridge" or "the Project").
Rokmaster's recently concluded metallurgical test program assessed proven metal recovery technologies to refine and optimize the metallurgical responses of the Revel Ridge Main Zone ("RRMZ") refractory mineralization.
For more than two years, Rokmaster has undertaken numerous metallurgical tests to advance the flowsheet from an initial overall gold recovery of 74.3% (Rokmaster news release, Sept 30, 2020). Recent metallurgical test work and repeatable Locked Cycle Tests ("LCT") provided an updated flowsheet that is returning overall gold recoveries at 96.8%.
The new flowsheet parameters used to achieve these high levels of recovery are:
- Grinding:
The Primary grind has been coarsened to a much more readily achievable P80 of ~150 micron from the historical ~30 micron P80.
- Flotation:
Bulk flotation of all sulphides recovers approximately 98.3% of the gold to a bulk concentrate in ~45% mass pull.
Bulk Concentrate regrind is now set at approximately 20-30 micron P80.
Lead recovery to a lead concentrate has increased from 57% to 75.7%.
Gold recovery to a lead concentrate is approximately 21.1%.
Zinc recovery to a zinc concentrate has increased from 51.0% to 69.5%.
Approximately 3.6% of the gold is recovered to the zinc concentrate. - Pressure Oxidation: The pressure oxidation parameters have been determined. Minor regrinding after pressure oxidation and prior to leaching, assisted in achieving a gold leach recovery before solution losses of 98.0%.
John Mirko, President and CEO of Rokmaster stated:
"Rokmaster has defined an efficient process flowsheet that achieves significantly improved recoveries of all target metals and is the first of its kind for the Revel Ridge (formally the J&L Property) Project, since work first began on the RRMZ in 1912. The metallurgical developments by Canenco Consulting Corp., Base Metallurgical Laboratories Ltd. and SGS Canada Inc. (Lakefield) have advanced the flowsheet to provide a robust, repeatable gold extraction process that significantly de-risks the Revel Ridge Project. Getting to this transformative stage has taken an impressive amount of testing and commitment, and we would like to thank our metallurgists for continued perseverance and achieving such excellent results to unlock the potential value of the RRMZ. With high gold recovery and solved metallurgy, Rokmaster will now progress with additional metallurgical testing of other variable parts of the RRMZ, including the visible native gold areas, updating the recent PEA, and engineering as it continues drilling for resource expansion on this rare world class asset with significant resources and exploration upside, located in a top tier safe location."
About Refractory Precious Metal Mineralization and Treatment:
Pressure Oxidation ("POX") is a robust process used to extract gold, copper, zinc, and other metals from refractory mineralization that typically give low recoveries when directly leached. The most common refractory minerals are pyrite and arsenopyrite, which are sulfides that trap the gold within them such as which is present at Revel Ridge. The POX process utilizes the injection of oxygen into slurries at temperatures around 220-230 degrees Celsius and elevated pressures around 440psi, to oxidize and liberate the minerals from refractory matrix. This process has been used since 1985 when it was first put into commercial production at Homestake's McLaughlin mine in California. It has increased in use since that time.
POX was selected as the most feasible processing technology for Rokmasters' refractory precious metal mineralization due to it being the most robust proven technology with "package plants" now being able to be purchased and built, its relatively smaller footprint compared with other oxidative process, its ability to provide a path to achieve high gold recoveries with RRMZ mineralization when compared with other available technologies.
The current resource at Revel Ridge consists of:
Measured & Indicated (M&I): 6,730,000 million tonnes ("MT") containing 1,357,800 ounces gold equivalent ("AuEq") @ 6.27 g/t AuEq and Inferred (Inf): 6,000,000 MT containing 1,220,400 ounces AuEq @ 6.33 g/t AuEq.
*(Technical Report and Updated Mineral Resource Estimate of the Revel Ridge Polymetallic Property Revelstoke Mining Division, British Columbia, Canada, William Stone, Ph.D., P.Geo. Fred Brown, P.Geo. Jarita Barry, P.Geo. David Burga, P.Geo. Eugene Puritch, P.Eng., FEC, CET Stacy Freudigmann, P.Eng. F.Aus.IMM. P&E Mining Consultants Inc. Report 411 Effective Date: November 15, 2021 Signing Date: January 17, 2022 filed on SEDAR.)
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. and by Mr. Eric Titley, P. Geo., who are independent of the Company and who are Qualified Persons as set out in National Instrument 43-101 and are 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.
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 and a Technical Report of an Updated Mineral Resource Estimate on the Revel Ridge Property, dated January 17, 2022.
- 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).1
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 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
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