PRESS RELEASE: According to OZ Minerals, production at the copper-gold operation Prominent Hill has continued in accordance with the mine plan and remains on track to achieve guidance.
The June quarter saw Prominent Hill produce 28,163t of copper and 32,136oz of gold.
The ramp up in production over the prior quarter was driven by an increase in underground ore mined. The second permanent underground access decline is on schedule for breakthrough in late August, which will assist the underground ore production ramp up through the second half of the year.
“Strong production and lower costs quarter on quarter see us tracking positively towards achieving annual guidance. The Prominent Hill mine plan has production ramping up in the latter half of the year, supported by completion of the second permanent decline expected in late August,” said Andrew Cole, managing director and CEO.
Development of the Carrapateena (iron-oxide copper-gold deposit) declines is also progressing to plan, with total development at 2,049m (1,142m to the face of the Tjati decline) and a vertical depth of 180m. The Tjati decline has moved into the Woomera Shale zone.
Geotechnical and water drilling was completed on the western access road during the quarter with results currently under review.
Development of the second decline boxcut is occurring simultaneously to the underground development of the decline. A short waste rise has been mined between the two declines, increasing the heading turnaround time and shortening the bogging cycle. Upon breakthrough into the boxcut, expected in late August, the second decline will be established as the primary ventilation circuit.
The dual decline approach removes the need for airway rises during the initial development phase, provides emergency egress and removes interaction between both mine vehicles and haulage fleet and mining and conveyor maintenance. The reduced profile Tjati decline and smaller second decline require an incremental increase of circa 30% in development waste volumes over the original single larger access decline design. Additional costs associated with increased material movement will be offset with savings from the removal of vent rises, emergency hoist and spillage protection from the original pre-feasibility study design.