PRODUCTION at Finders Resources’ Wetar Copper Project has been impacted by an interruption to the 25,000 tonnes/annum copper cathode SX-EW plant. An overflow of organic and aqueous solution into the electrowinning (EW) circuit affected production in late September and early October.
The solution containing contaminants and impurities from the solvent extraction (SX) settlers overflowed through the circuit and into the clean electrolyte for the EW circuit. This affected the operation of the EW circuit and its ability to plate copper cathode.
Finders advised of the incident on September 27 and said that the contaminated electrolyte had been removed from the circuit with fresh reagents added and production restored. It said clean-up of the EW circuit would continue for a month.
As a consequence, copper cathode production for the September quarter would be reduced to below the record achieved in the June quarter, with production in October also impacted.
The company said current best estimates on the total production shortfall against the June 2017 quarter was approximately 500 tonnes of copper cathode. It also said that operating costs in the period would increase due to replacement of reagents in the circuits and an increase in power usage due to circuit efficiencies. Operating costs would reduce as the circuit steadily returned to normal operations.
During the June quarter 6804 tonnes of copper were stripped, up from 6125 tonnes in the March quarter. Copper sales of 7419 tonnes were also a record, up from 7153 in the previous quarter and the average realised price in both quarters was US$2.60 per pound.
Finders said in its quarterly report that consistent mining and processing rates were maintained. Both the 3000 tonnes/annum SX-EW and 25,000 tonnes SX-EW plants and the neutralisation plant continued to operate as expected.
In the six months to June 30, the project produced 12,929 tonnes of copper cathode and sold 14,572 tonnes. Managing director Barry Cahill said, “The June 2017 half year result consolidates what has been a transformational period for Finders, and has confirmed the company as a significant copper producer amongst its ASX-listed copper peers with robust financial and production metrics.”