Artemis Resources’ focussed 2018 drilling efforts at its fully owned Carlow Castle gold-copper-cobalt project have paid off handsomely, with the company expanding the resource tonnage by 71% to 7.7 million tonnes grading 1.06g/t gold, 0.51% copper and 0.08% cobalt this week.
The deposit is located near Karratha in the Pilbara region of WA and only 30km northeast of the company’s future ore processing hub at the Radio Hill plant.
Artemis has more than doubled the drilling metres completed at Carlow Castle since the last mineral resource estimate in January last year and the update now paves the way to develop the deposit further technically and in a methodical fashion.
Chief Executive Officer Wayne Bramwell said: “The 2018 Carlow Castle Au-Cu-Co drilling program has significantly increased the inferred resource to 7.7Mt. The growth in tonnage, in conjunction with our preliminary metallurgical programme confirming Carlow Castle’s amenability to low cost processing technology, now builds a platform to advance Carlow Castle in a systematic manner.”
“The next round of diamond drilling will focus on improving the structural understanding of the resource and better inform proposed extensional drilling.”
Only last month, the company reported exceptional recoveries of gold, copper and cobalt from preliminary metallurgical test work on two high grade, bulk ore composites from the project.
Artemis was able to recover up to 48% of the gold content via gravity separation techniques.
The gold not recovered by gravity or into flotation concentrates was easily won by cyanide leaching, leading to the excellent overall recovery of between 98% and 99% for gold and an average of 96% of the total silver content.
In addition, between 77% and 85% of the total contained copper content was recovered, producing a premium grade copper concentrate of about 30% from conventional metallurgical flotation processes.
The company also attained sublime cobalt recoveries ranging from 73% to 79% with flotation producing concentrates of the valuable metal between 2.3% and 5.3% cobalt, which are typical smelter feed grades, with grades exceeding 5% cobalt considered to be high grade.
The laboratory scale test work was designed to determine the metallurgical recovery characteristics of fresh ore composites from Carlow Castle and their amenability to conventional gravity, leach and flotation processing.
The results confirmed that the deposit’s ores could be separated producing high recoveries of the in-situ metallic content and providing support for further optimisation of an ore processing flowsheet from additional, ongoing geometallurgical test work studies.
Mr Bramwell said at the time: “Artemis is encouraged by the amenability of the deposit to conventional processing options and the excellent recoveries of the three key minerals.”
“Gold and high-grade copper concentrates will be the primary value drivers at Carlow Castle with cobalt representing a third and valuable product stream that should appeal to many potential off-take partners.”
The results of the metallurgical test work program and the updated mineral resources for Carlow Castle will underpin the project’s development activities, which will include open pit optimisation studies to maximise revenue from the combined metal ore stream from the intriguing deposit.
The results of the test work will form the basis of discussions with smelters and potential off-take partners and enable the commencement of an informed scoping study for the project set down for the first half of 2019.
The metallurgical test work results and solid mineral resource base are very encouraging and the ultimate aim will be to optimise the ore treatment processes to obtain the highest metal recoveries possible from the multi-commodity ore deposit.
By Matt Birney
