Nova Minerals Limited (ASX: NVA) has received highly encouraging results from its first phase metallurgical test work on mineralisation from its high-grade RPM North Deposit in Alaska.
Leach Tests were conducted at Bureau Veritas Vancouver to determine the potential for intensive leach of gold contained in flotation concentrate. Results were outstanding with 96.2% of gold recovered. Concentrate leach recovery was calculated by Bureau Veritas based on gold recovered into solution and gold left in solid tailings. Relatively minor losses can be expected from the electrowinning circuit.
Flotation Tests were conducted at Bureau Veritas Vancouver to determine the potential for flotation to concentrate gold. Results were outstanding with 92.4% of gold recovered into a concentrate with 14.3% of the flotation feed mass. A high flotation concentration ratio is important as it allows fine grinding and intensive leaching of a small flotation concentrate, at a reasonable cost.
Test Work Flotation and leach recoveries were 92.4% and 96.2% respectively. Combined Flotation and leach recovery is 88.9% using 73 microns in flotation and 16 microns in leaching. Minor losses could be expected.
Highlights
• Outstanding metallurgical results demonstrate gold recoveries of over 96% through the leach circuit at the RPM North Deposit;
o The average head grade of the RPM metallurgical composite was 1.34 g/t Au. The overall average tail grade achieved from the composite was less than 0.15 g/t Au.
• The tail grades achieved at RPM of less than 0.15 g/t Au are very encouraging and have resulted from optimization of the process flowsheet and test work parameters since testing commenced on greater Estelle samples. Further test work will be undertaken at head grades that are in line with the expected process plant feed grades emanating from the Phase 2 Scoping Study, due later this year.
• The flow sheet for the test work comprises conventional flotation concentrate followed by fine grind cyanide leaching.
• Test work continues across all the Estelle Gold Trend deposits for inclusion in the PFS due late 2023, which will include the RPM North, RPM South, and the Korbel Deposits.
• RPM continues to deliver thick high-grade interceptions with RPM-008 recently returning 140m @ 6.5 g/t Au following on from the previous announced RPM-005 discovery hole of 132m @ 10.1 g/t Au
• Continuous flow of drill results from the ongoing Korbel and RPM programs to be reported throughout the year, as assay results become available from the laboratory.
“The new metallurgical test work from the RPM Deposit at Estelle continues to demonstrate encouraging gold recoveries on the high-grade deposit using composite samples of only 1.34 g/t,” CEO, Christopher Gerteisen, said.
“These results from RPM are a significant improvement on the positive results already achieved from the Korbel Deposit and harmonised with the existing flowsheet.
“The consistently low tail grades achieved in test work at RPM will be carried through into the project studies and evaluations.”
For further information please visit: https://novaminerals.com.au/
