THE BOURSE WHISPERER: De Grey Mining (ASX: DEG) announced positive results from metallurgical test work recently undertaken on samples from within the proposed Toweranna open pit resource area at the company’s Pilbara gold project in Western Australia.
De Grey Mining carried out test work to assess conventional carbon-in-leach (CIL) gold recovery from both oxidised and fresh rock.
The company indicated it had obtained high gold recoveries from all of the oxide zone samples, ranging from 92 per cent while the fresh rock samples returned results with 94.7 per cent gold recovery.
De Grey said the results indicate Toweranna mineralisation is free milling and fully amenable to convention CIL processing.
Separate samples were also tested for gravity recovery, with oxide and fresh rock samples returning recoveries of 20.8 per cent and 54.3 per cent respectively.
The company considers the high levels of gravity gold indicate that it may be possible to lift total gold recovery by installing a gravity concentrator ahead of the CIL circuit and as such will evaluate the merits of employing gravity extraction in subsequent test work.
“Toweranna continues to grow in stature with strong resource growth potential and high recovery with conventional CIL processing characteristics,” De Grey Mining technical director Andy Beckwith said in the company’s announcement to the Australian Securities Exchange.
“On-going drilling results continue to define multiple stacked lodes to at least 200 metres depth.
“Once drill assays are finalised, we will update the zero to 200 metres open pit resource and run open pit optimisations.
“We are increasingly seeing free gold in the veins in core and the high gold recovery together with the simple free milling nature is encouraging.
“Toweranna is poised as a game changer as it has the potential to rapidly increase resources and improve the PFS economics.”