Xanadu Mines Ltd’s (ASX:XAM) (TSX:XAM) (FRA:02X) metallurgical test program on sulphide ore from the flagship Kharmagtai project in the South Gobi region of Mongolia has improved copper and gold recoveries.
The new test program has improved copper recoveries by around 4.5% to an average recovery of 89.5% for the two main metallurgical composites.
Gold recoveries have increased by around 3% to achieve an average recovery of 69.7% for the two main metallurgical composites.
Concentrate grades increase
This work has also resulted in increases in copper concentrate copper and gold grades.
Xanadu’s managing director and CEO Dr Andrew Stewart said: “We are extremely pleased with these new metallurgical results from Kharmagtai, which are in line with or better than expected at this stage in the project's life and we are comfortable that additional improvements can be made further down the track.”
Expands on previous work
The new metallurgical test program has expanded on that conducted during the 2018 mineral resource estimate and 2019 scoping study.
This work was conducted at SGS Canada in Vancouver, BC under the direction of David Middleditch and Andy Holloway of AGP Mining Consultants Inc.
New composites, three domain and nine variability, were selected by Xanadu geologists with input from AGP personnel.
These were selected to represent the main geological and alteration domains within the open pit portion of the three existing deposits and to be representative of material in the 2018 resource estimate.
Copper and gold recoveries averaged 89.5% and 69.7% respectively for the two main master composites, ranging from 89.3% to 89.7% for copper and 60.8% to 78.7% for gold.
Copper concentrates graded at an average of 25.2% copper and 26.5 g/t gold and ranged from 24.8 to 25.6% copper and 21.5 to 30.0 g/t gold.
Stewart said, “These early-stage flotation test results are very encouraging and indicate that a standard crushing, grinding and flotation process will be enough to deliver good extraction of the economic minerals from the deposit.
“In combination with the low content of deleterious elements, we foresee no significant hurdles to producing a high-quality concentrate via standard processing pathways that will be in high demand from all the major global copper smelters, at the time of production.”
Flotation test work on the composites consisted of a series of batch rougher and cleaner tests with locked cycle tests conducted on the two main Master Composites.
The key differences between the 2008 test work and the 2019 test work relate to head grade and sample selection.
Further optimisation work in the future may lead to further improvements.