Rise Gold Achieves 99% Gold Recovery - 98.7 gold recovery to concentrates averaging 117 gpt gold
- Coarse grind of 80% passing 180 microns
- Simple flotation reagent which is biodegradable and has no odor
- Inert sand tailings with negligible metal content and no acid generation potential
Grass Valley, California--(Newsfile Corp. - February 22, 2022) - - Rise Gold Corp. (CSE: RISE) (OTCQX: RYES) (the "Company") reports excellent metallurgical gold recoveries using a simple and environmentally friendly reagent scheme.
The Company provided a drill core sample from Drillhole I-19-13A to McClelland Laboratories, Inc. located in Reno, Nevada. The sample composite, taken over a 15.7 m core length was calculated to have a head grade of 8.5 gpt gold. The composite was ground to 80% passing 180 microns and subjected to gravity concentration followed by one stage rougher flotation. Total gold recovery was 98.7% to concentrates averaging 117 gpt gold. Gravity concentration recovered 65.8% of the gold to a concentrate grading 5,180 gpt gold and flotation recovered 32.9% of the gold to a concentrate grading 40 gpt gold. The Company believes that the flotation concentrate grade may be substantially improved with additional test work as the historic mine achieved average flotation concentrate grades of 134 gpt gold.
Gold at the Idaho-Maryland Mine is liberated at a coarse grind size relative to a number of other gold deposits. The historic grind size from the operating mine is believed to have been approximately 190 microns. The current test work has shown excellent gold recoveries at a grind of 80% passing 180 microns. A comparison shows the grind size at Idaho-Maryland to be approximately 3x coarser than a number of other deposits as shown in Table 1. A coarse grind provides benefits including a reduction in power applied per ton of feed to the grinding unit and more efficient dewatering of sand tailings. Important environmental benefits are achieved with a coarser grind due to the sand tailings have improved drainage, less dust generation due to lower silt content, higher geotechnical stability, and less erosion and siltation concerns.
McClelland conducted flotation test work with a variety of reagents and achieved excellent recoveries using only a frother and Aerophine 3418A. Aerophine 3418 promoter is a unique, phosphine-based collector, which has no odor, is biodegradable and is not harmful to fish, aquatic invertebrates or plants. Mineral processing at the Idaho-Maryland is designed as a closed circuit to prevent the possibility of reagents entering local waterbodies and the use of environmentally friendly reagents offers additional environmental protection. The cost of using this reagent would be insignificant at approximately $1.20 per ton processed, based on budgetary quotes and dosages used during test work.
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