THE DRILL SERGEANT: De Grey Mining reported on preliminary ore sorting test work undertaken on geological samples from the Toweranna gold deposit within the company’s Pilbara gold project in Western Australia.
De Grey noted that mineralised quartz and sulphide vein material was efficiently separated from non-mineralised host granitoid and sediments with single pass laser sorting.
The results also showed the sorting was effective at a coarse feed size of 20mm to 100mm with negligible quartz observed in the reject fraction, indicating very low ore loss.
De Grey considers the results are excellent and clearly demonstrate the potential to upgrade and concentrate the quartz vein material prior to trucking to the proposed processing plant.
“The results provide additional confidence that ore sorting may provide significant added benefits through enhanced grade increases that may enhance future economics at Toweranna,” De Grey Mining said in its ASX announcement.
“Further test work is considered warranted.”
The company considers the application of ore sorting at Toweranna has potential to improve project economics and increase gold production through:
Facilitation of bulk mining that would reduce unit mining costs and ore loss experienced in selective mining and capture additional mineralisation outside the modelled resource;
Rejection of waste material ahead of milling, leaching and tails disposal leading to lower processing costs; and
A possible reduction in ore transport costs.
The company indicated ongoing conventional metallurgical test work, ore sorting test work and financial evaluation is considered warranted.
It already has further activities planned that include finalising metallurgical test work on the purpose drilled PQ core, which is already well advanced by ALS Metallurgy.