Positive Initial Metallurgical Results Form Rattlesnake Hills Gold Project
SASKATOON - GFG Resources Inc. has received positive metallurgical results from the Rattlesnake Hills Gold Project (RSH) located in Wyoming, from its option partner, Group 11 Technologies Inc. These are the first test results in the process to develop In-situ Recovery (ISR) technology for gold mining using EnviroMetal Technologies Inc. non-cyanide and environmentally friendly leaching solution. The gold recovery tests from uncrushed half-core samples demonstrated recoveries ranging from 15.9% to 77.5%, averaging 48.2% while the bottle roll testing of crushed material returned gold recoveries ranging from 38.3% to 89.5%, averaging 61.4%.
“These initial results have exceeded our and Group 11’s expectations and this is an exciting development for our shareholders, stakeholders and the gold mining industry as a whole,” stated Brian Skanderbeg, President and CEO of GFG. “We look forward to the next phase of testing as they continue along the path of proving and adapting ISR technology to gold mining.”
Dennis Stover, Group 11 and enCore Energy Corps’ Chief Technical Officer and co-discoverer of the in-situ recovery process in the uranium sector, said, “Group 11 is very pleased with the initial tests which showed strong results to extract gold from the existing core samples with an environmentally-friendly solvent. This first step will provide the basis for future tests to be conducted on the use of the lixiviant in combination with ISR technology. Group 11 is working to create new environmentally-friendly options to extract gold and other metals through less invasive ISR extraction which is in widespread use in the uranium sector.”
The Phase 1 program was designed to conduct staged metallurgical tests on core samples from across a broad range of mineralization and grade profiles from previously drilled core from the RSH Project. The objective was to assess the amenability and recovery rates for extracting gold from the core using the eco-friendly water-based solution. Group 11 selected 17 half-core and 22 composite core chip samples from the RSH Project with the objective of evaluating gold recovery and leach kinetics to provide baseline data for future studies focused on in-situ leaching using EnviroMetal’s environmentally superior leach chemistry.
The half core samples were leached whole and uncrushed in EnviroMetal’s solution at 28% - 45% pulp density for 22 to 92 days to investigate gold recovery for ISR application. Gold recoveries ranged from 15.9% to 77.5%, averaging 48.2%. These samples were tested whole without crushing to more closely emulate expected results from an ISR environment.
The rock samples were crushed to -2.5 mm and tested via bottle roll methodology with EnviroMetal’s solution at 30% pulp density for 9 to 28 days at a neutral pH to investigate gold recovery. Gold recoveries ranged from 38.3% to 89.5%, averaging 61.4%. Leaching with the bottle roll on crushed material provided faster kinetics and higher recoveries, as would be expected, due to the increased surface area exposed to the solution.
Although not directly comparable due to significantly different testing parameters, these new bottle roll test results compare favorably with traditional bottle roll results from testing conducted in 2009 by Resource Development Inc. (“RDI”) for the RSH Project. The RDI testing utilized cyanide with 1g/l of NaCN, a pH of 11, 40% solids, 72-hour leaching time and a very fine grain size of 80% less than .074mm. Gold recoveries from these historic cyanide bottle roll tests ranged from 13.7% to 65.4%, averaging 43.4% from 15 composite drill core samples.
With successful initial test work that exceeded recovery rate expectations, Group 11 will proceed to conduct further ISR analyses and data review related to the RSH Project. The technical review will further assess the amenability and recovery rates for extracting gold using the eco-friendly water-based solution. Next steps to advance the RSH Project may include additional laboratory tests, additional drill tests and related project permitting.