Carnavale Resources Ltd (ASX:CAV) is buoyed by “exceptional” results returned during ongoing metallurgical test-work for Swiftsure Deposit within the Kookynie Gold Project 60 kilometres south of Leonora in Western Australia’s Eastern Goldfields.
The results, including high overall gold recovery rates ranging from 98.9%-99.5%, high recovery of gravity gold averaging 87.1% and high recovery from carbon in leach (CIL) test of 99.7%, have the potential to enhance project economics.
Providing even further encouragement in the testing by Independent Metallurgical Operations Pty Ltd (IMO) are the following:
- Rapid leach kinetics shows 90.6% to 91.6% recovery after four hours of leaching;
- The optimum grind size was found to be course by industry standards, being 106 micron;
- Low cyanide consumption and no lime consumption in leach test-work; and
- Confirms earlier metallurgical test-work recoveries of 97-99% recoveries from Leachwell test-work at ALS laboratories
“Upgrades profitability”
CEO Humphrey Hale said: “CAV is delighted with the results of the metallurgical work carried out by IMO. The improvement in recovery upgrades the profitability of the Swiftsure Deposit and confirms the results of the earlier Leachwell testing.
“The test-work has delivered exceptional results with the latest results revealing an enviable +99% gold recovery with the easily recovered gravity portion representing about 87%.
“These test work results support the geologist’s observations of abundant course free milling gold in the drill chips.”
READ: Carnavale Resources submits Mining Licence Application for Swiftsure deposit at Kookynie Gold Project
Follow-up testing
CAV engaged IMO to follow up previous Leachwell test-work that indicated outstanding gold recoveries could be achieved at the Kookynie Gold Project.
IMO conducted tests on samples of mineralised material that represents the high-grade zone within the Swiftsure Deposit.
A composite sample of 28 kilograms was collected from RC drilling chips that represented the high-grade gold zone.
The Swiftsure Deposit is characterized by bonanza-grade zones of mineralisation contained within plunging shoots.
Swiftsure scoping study
CAV recently released a scoping study for the Swiftsure Deposit which indicated that the project could deliver a pre-tax NPV of approximately A$91 million with an IRR of 192% at a A$3,500 gold price.
READ: Carnavale Resources unveils robust maiden gold resource and positive scoping study for Kookynie
This study assumed a metallurgical recovery of 95%, compared to results from this current test-work which suggests that recoveries greater than 99% may be possible.
Variability work completed during the study indicates that a 1% variation in recovery generates a $2.2 million variation in undiscounted cashflow and a $1.9 million variation in the project NPV.
The sensitivity outcomes show that the project remains viable across the range of recoveries considered.
Based on the results to date of the Swiftsure Leach Amenability Test-Work program CAV will continue metallurgical work to include additional leach test-work on multiple composite samples representing the variability in gold grade, ore type and depth/weathering profile throughout the Swiftsure deposit.