Cyclone Metals Ltd (ASX:CLE) has found success during its latest round of metallurgical test-work on samples from the Lady Ethleen Copper-Gold Project in northwest Queensland.
The test-work involved initial leach tests on three sample types using just acid to simulate conventional leaching methods, providing a reference point so that Cyclone could compare it to alkaline leaching technology.
Promisingly, Cyclone recovered as much as 92.9% copper by using GlyLeach™, a specialised liquid medium that’s used to selectively extract metal from an ore or mineral.
Based on the success of the initial results, stage two of the test-work program has been approved and is underway.
Developing multi-commodity portfolio
Cyclone Metals non-executive chairman Terry Donnelly said: “These are very encouraging results and allow the company to move to stage two testing.
“Together with the newly acquired Nickol River Mining Project and our existing Yalardy Project, the company is in an excellent position to further develop a portfolio of prospective projects in multiple commodities including gold, copper and rare earths."
The results are in
During the stage one test-work, acid-only results for the Lady Ethleen sample demonstrated copper recoveries of 85% for oxide, 49.6% for transitional and 44.1% for sulphide.
However, after curing the as-received samples in dilute acid at 10 kilograms per tonne and leaching with the specialised GlyLeach™ solution, copper recoveries were found to increase to 92.9% for oxide, 65.2% for transitional and 64.9% for sulphide.
These numbers are expected to increase further if the sample is ground prior to processing, with the potential to return up to roughly 85% for sulphide.
Notably, this process allows for very minimal acid usage, which is entirely consumed followed by the use of the recoverable GlyLeach™ solution.
This could possibly trigger reduced costs and a significantly more environmentally friendly process.
Transition to stage two
Now in stage two of the program, Cyclone intends to take the test-work a step further.
Work will include:
- Small column leach tests on samples with acid cure, glycine leach stripped with resin and hot water wash to simulate heap leaching;
- Continuous vat leach tests on samples with acid cure, glycine leach stripped with resin and hot water wash;
- Reactor leach tests on samples with acid cure, glycine leach stripped with resin and hot water wash to simulate a horizontally rotating reactor (similar to a cement mixer truck); and
- Additional inclusion of cyanide using Glycat™ technology to recover any gold present in the samples.
Based on the stage two results, the company will consider conducting pilot trials using truck- or trailer-mounted horizontal reactors.
These will be based on- or near-site to demonstrate their processing practicality at an increased scale.
Lady Ethleen
Cyclone wholly owns the Lady Ethleen tenement, which sits in close proximity to the broader Wee MacGregor Copper Project in northwest Queensland.
Currently, the tenement is being used for a trial mining and processing exercise that centres on a newly developed green leaching process known as GlyLeach™.
A successful trial may trigger a significant shift in future processing technology and will, in turn, facilitate the possible development of Cyclone’s part-owned Wee Macgregor Project.
The results may also impact other small assets in the district, which could be economic with access to appropriate processing technology.