Pilbara metallurgy looking good for Artemis

Artemis Resources has completed preliminary metallurgical test work on ore composites from its Carlow Castle gold-copper-cobalt project located near Karratha in WA, saying that the materials are amenable to gravity recovery of gold and conventional base metal flotation ore processing.

The studies on “high grade” and “average grade” ores from the deposit revealed that 32% and 48% of the gold content is directly recoverable by gravity methods for those separate composites.

Flotation test work on the “high grade” and “average grade” ores also revealed that 82% and 77% of the contained copper content reported to the copper concentrate for those separate ore composites.

Additionally, the flotation work recovered 32% and 27% of the non-gravity gold content into the separate copper concentrates as a by-product.

This means that 64% of the total gold content reported to the gravity fraction and copper concentrate for the “high grade” ore composite and 75% of the total gold content reported to the gravity fraction and copper concentrate for the “average grade” ore composite.

The company said it expected the bulk of the remaining gold content to report to the cobalt flotation processing and/or via a conventional gold leaching circuit arrangement.

Flotation test work for the cobalt product is at an early stage, with the initial focus on screening of reagents to maximise recoveries of the cobalt metal.

Artemis Chief Executive Officer Wayne Bramwell said: “This first pass metallurgical programme indicates Carlow Castle is amenable to low cost gravity gold recovery and base metal flotation processes. The high grade copper concentrates (with gold credits) produced are encouraging and cobalt flotation is now progressing.”

The company said it expected to recover gold from both gravity and leach processing to generate a product suitable for smelting and production of gold doré – or unrefined gold bullion – at the proposed mine site.

Copper and cobalt will be recovered via conventional flotation processing to produce separate concentrates of the metals.

Artemis is investigating options to maximise the total gold and copper recoveries from the Carlow Castle ores.

Results of the program are expected next month, with reporting of all assay data from the first-pass metallurgical studies.

The results of the test work will form the basis of discussions with potential offtake partners and enable the commencement of an informed scoping study during the first quarter of 2019.

The current indicated and inferred mineral resource for Carlow Castle is 2.3 million grading 1.3g/t gold, 0.5% copper, 0.11% cobalt and 1.6g/t silver, within a larger global resource of 4.5 million tonnes @ 0.9g/t gold, 0.4% copper, 0.07% cobalt and 1.3g/t silver.

The mineral resource dates from January this year and the company will update the estimate during the current quarter, having more than tripled the amount of drilling it had completed at the project only a year ago.

The initial metallurgical test work results for Carlow Castle appear to be encouraging and the prize will be optimising the processes to obtain the highest metal recoveries possible from the multi-commodity ore deposit.