Bayhorse Silver Achieves Near Total Silver Recovery With Two Stage Leaching, Bayhorse Silver Mine, Oregon, USA
Vancouver, British Columbia--(Newsfile Corp. - June 6, 2018) - Bayhorse Silver Inc. (TSXV: BHS) (the "Company" or "Bayhorse") has achieved near total silver recovery (NTSR) from the recent two stage leaching test program conducted for the Company by Richard Hammen, Ph.D. Chemistry, on its Bayhorse Silver Mine, Oregon, USA. The Company is in the process of establishing the effectiveness of the processing method at commercial levels of production.
Dr. Hammen has taken his research success in chemical separations, begun while he was Director of Chemistry at Jet Propulsion Labs (JPL) of Pasadena, CA, and applied it to mineral processing streams to improve recovery of metals over what is currently in practice in the mining industry.
In the leaching test (hydrometallurgical process) on 25 kg of Bayhorse Silver Mine mineralized material grading 25.6 oz/ton (796 g/ton) silver, Dr. Hammen achieved essentially total recovery of the silver as shown in the table below. Using ion exchange purification and reduction, the resultant silver can be formed into pure silver bars.
| Summary of 2 Stage Silver leach results | ppm Ag | |
| Head Assay | grams Ag/ton of ore | 796 |
| Tails after leaching | grams Ag/ton of ore | <2 |
| Ag in leach solutions | grams Ag/ton of ore | 792 |
The Process
The combined use of both electrophilic and nucleophilic classes of chemicals that has been developed for leaching the silver bearing material at the Bayhorse Silver Mine lifts the yield of silver that can be extracted from the 60% range to the 99+% level. If the process is effective at commercial levels of production, it may affect the potential economics of the Company's silver mine.
The chart supports solution analyses by mass balance of silver in both the mineralization and the tailings. Since the lower limit of detection (LDL) for the ICP instrument used to measure the silver in the tailings was 2 ppm then the silver "measurement" was less than 2 ppm (<2 ppm). Using the 2 ppm LDL number, the extraction of the silver from the mineralization by these orthogonal leaches is virtually complete.
Dr Hammen states, "The quantity of reagents used will be refined in further test work leaching of a one ton sample of Bayhorse "ore-sorted" mineralized material, followed by silver purification by ion exchange or Solid Phase Extraction."
Previous hydrometallurgy efforts on Bayhorse mineralization, using other chemical leaching methods only extracted 55%-65% of the silver, a level not competitive with other extraction methods. Flotation tests were able to achieve only a maximum 89-90% recovery.
Bayhorse CEO Graeme O'Neill comments, "At this stage we are focused on reducing our mining and processing costs, including minimizing the normal downstream losses that occur from shipping, smelting and refining. Addressing these issues now, rather than down the road, will improve our ability to operate in a lean metals pricing environment."
Assaying of the leachate and tails reported in the above table was undertaken by American Analytical Labs, Osburn, Idaho. The analytical method used for the silver analysis consisted of a 40 gram sample subjected to ICP finish followed by fire assay.
Next Steps
With the successful completion of the initial leach test, the Company is ready to scale the testing process. The Company will ship approximately one ton of crushed development material to Dr. Hammen, who is preparing for the larger scale testing program. The crushing is underway and the one ton bags are being prepared for shipping. The leaching tests are expected to take 30 days and the results of this test will be reported when available.
Dr. Hammen graduated from Stanford University, obtained his Doctorate in Chemistry from the University of Wisconsin and completed his post-Doctoral studies in Chemistry from UCLA. He is the patent holder, or co-patent holder of seven current patents and is the author, or co-author, of a number of scientific publications on, among other subjects, metals separation in aqueous solutions.
The Company advises it is not basing any decision to produce on a feasibility study of mineral reserves demonstrating economic and technical viability and also advises there is increased uncertainty and specific economic and technical risks of failure associated with any production decision.
****************************************************************************************
This News Release has been prepared on behalf of the Bayhorse Silver Inc. Board of Directors, which accepts full responsibility for its contents. The technical content of this news release has been prepared under the supervision of and has been approved by Dr. Stewart Jackson, P.Geo., a Qualified Person under National Instrument 43-101. He is a technical advisor to the Company and holds incentive stock options in the Company.
On Behalf of the Board.
Graeme O'Neill, CEO
604-684-3394
Bayhorse Silver Inc., a junior exploration company, has earned a 100% interest in the historic Bayhorse Silver Mine, Oregon, USA.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.