NON-TOXIC, CYANIDE-FREE TECHNOLOGY CAN POTENTIALLY DOUBLE SILVER RECOVERIES AND SIGNIFICANTLY CUT LEACHING TIMES
VANCOUVER, BC, April 2, 2024 — Silver One Resources Inc. (TSXV: SVE) (OTCQX: SLVRF); (FSE: BRK1) – “Silver One” or the “Company”) announces the results of initial metallurgical testing using a novel, cyanide-free leaching process that has the potential to double silver recoveries and reduce leaching times. The leaching process is used in conjunction with a unique extraction process which is suitable for the recovery of silver from refractory mineralization. This innovative leaching process involves a trademarked technology called TNS, developed by Extrakt Processing Solutions, LLC (“EPS”) Ky, USA. The tests were conducted on representative samples of the largest heap leach pad (LP1) from the Company’s 100% owned, past-producing Candelaria Silver Mine in Nevada. Recently, EPS announced a strategic global alliance with Bechtel Energy Technologies & Solutions, Inc. (“Bechtel”) to commercialize Extrakt’s groundbreaking TNS technology (see ).
Highlights
Preliminary metallurgical testing using EPS’ proprietary solutions have significantly increased Candelaria’s leach pad silver recoveries, exceeding 100% in comparison to previous testing using cyanide leaching (see Company’s news release of May 21, 2019). The sample tested consists of leached oxides from LP1, crushed to April 19, 2018 and May 21, 2019, and figure 1 for the location of LP1). Additional short-term (5-15 minutes) milling to 550 and 110 microns (0.55 and 0.11 mm) increases the leach pad recoveries to 59.9% and 64.4%, respectively. The use of the trademarked TNS technology has positive ESG implications, notably because it reduces environmental impact. Unlike cyanide use, this process consumes minimal water, and no toxic effluents are produced. Furthermore, the residues (tailings) are inert and non-acid generating. Additional testing on material from both the existing leach pads and fresh ore is planned for the second half of 2024.
Gregory Crowe, President and CEO commented: “The impressive results from the initial testing using EPS’ technology have encouraged Silver One to expand this testing to cover both leach pads and fresh mineralization. The results show the technology performs well in the treatment of difficult or refractory mineralized material, such as the partially leached material on the Candelaria heap leach pads. The use of these proprietary solutions yields potential for possibly doubling silver recoveries in comparison to traditional cyanide leaching. This may positively impact the overall economics of the project. EPS’ leaching agents not only improve silver extraction but are also more environmentally friendly and save water by assisting in the dewatering of tailings, and the extraction process is simpler and potentially less costly. Furthermore, we are optimistic about this innovative technology as it is backed up by EPS’ years of research and development. We are looking forward to continuing testing to optimize the operating parameters, test diverse types of mineralized material including fresh never-leached material, and validate the results.”
Background
EPS has developed a novel solid-liquids separation technology (TNS) and leach processes to recover metals. EPS extensive research and development has resulted in constant improvements and adaptations that have accumulated 40 patents, producing, in the process, formulations suitable to separate metals from complex oxide and refractory mineralized materials. TNS technology was designed for the application of liquid solids separation in dewatering of mine waste and is also very effective in separating hydrocarbons in oil-sands. The TNS process, combined with its unique cyanide-free leach technology especially formulated to extract metals, has demonstrated to recover more silver and gold than traditional leaching methods. The traditional silver cyanide leaching typically takes several hours to several days using agitated leaching techniques. However, EPS’ innovative technology uses patented chemistry to extract metals in less time than an agitated leaching system. It also separates liquids from solids, enabling dry-stacked tailings; it works with coarse particles (≤2 mm or 2000 microns material in Candelaria’ s case) and is not inhibited by the presence of clays. Thus, the process potentially reduces capital and operating costs while increasing metal recovery. The TNS technology has been tested on materials from mine sites from various parts of the world and piloted successfully in dewatering oil-sand tailings in Canada and with major coal operation in the U.S. The leach technology is also in the process of being tested in the extraction of gold from tailings for a project in Canada.
Testing and Leach Results
A bulk sample representative of leach pad 1 (LP1) weighing 228 kg and entirely crushed to ≤2 mm (Belen, NM, was shipped to EPS laboratory in Kentucky for metallurgical testing. The material consisted of leached oxide and partially refractory material with an average silver head grade of 48.12 g/t, which was considered depleted by Kinross when mining and processing ceased in 1998. A representative portion of the bulk sample was weighed and sieved to separate two fractions. Material smaller than 2 millimeters was used for testing. The tests were conducted on 1 to 2 kg splits of the sieved ( The current silver recoveries using EPS’ proprietary solutions average 49% on samples as received at the lab (May 21, 2019). Further milling for short periods (5 to 13 minutes) yields finer material