Havilah Resources Ltd. posted an updated resource estimate for its North Portia property in South Australia. The new estimate incorporates recent infill drilling and divides the deposit into three zones: upper oxide gold, supergene sulfide copper-cobalt-gold and primary sulfide copper-gold.
The company said May 15 that the analysis includes an initial cobalt resource and a new oxide gold zone, and mineralization in the upper 150 meters of the deposit was largely upgraded to the measured category. Havilah expects to be able to recover the cobalt during copper sulfide flotation processing.
"This establishes, with a high level of confidence, sufficient JORC resources to sustain ongoing mining operations at Portia with the addition of mining of the North Portia project," Havilah CEO Walter Richards said in the statement.
North Portia hosts measured, indicated and inferred supergene sulfide resources totaling 3.9 million tonnes grading 0.73% copper, 0.51 g/t of gold, 154 parts per million of cobalt and 275 ppm of molybdenum. Contained metal comprises 28,200 tonnes of copper, 63,200 ounces of gold, 594 tonnes of cobalt and 1,060 tonnes of molybdenum.
Together, oxide and sulfide resources at North Portia are estimated to contain 101,400 tonnes of copper, 258,800 ounces of gold, 594 tonnes of cobalt and 5,630 tonnes of molybdenum.
The analysis uses cutoffs of 0.5 g/t of gold for oxide gold material and 0.4% copper for supergene sulfide material, while primary sulfide material was not re-estimated. The new estimate also incorporates data from 21,309 meters of drilling completed by the company and 20,434 meters of drilling completed by a previous project operator.
Havilah also said metallurgical testing is ongoing, along with negotiations for a mining agreement with Consolidated Mining and Civil Pty. Ltd. The companies signed a memorandum of understanding in November 2017.