A simple hydrochloric acid leach in room temperature conditions has achieved high magnet rare earth recoveries from clay samples from the Neo prospect, part of Voltaic Strategic Resources’ Paddys Well project in the Western Australian Gascoyne.
Average recoveries of 91 per cent and a 96 per cent maximum compare well to Voltaic’s peers and build on previous returns which have indicated easy upstream beneficiation and reduced requirements for a full-scale processing plant.
First pass drilling over the prospect earlier in the year identified significant clay intercepts with around 80 metre widths from surface and the move to metallurgy has now demonstrated easily recovered, high value magnet rare earths.
Voltaic Chief Executive Michael Walshe said the rare earths are present as ultrafine, primary, relict monazite or secondary rhabdophane particles, and the company’s focus will now be finding the primary hard rock source of mineralisation interpreted to be of carbonatite origin.
The Company notes the success that other exploration companies in the region have achieved, including Hastings Technology Metals and Dreadnought Resources, in identifying carbonatite hosted REE’s which have been shown to have a high proportion of the valuable MREEs neodymium and praseodymium in the TREO matrix, and favourable metallurgical characteristics for economic extraction,” Mr Walshe said.
He added the leach recoveries are preliminary and non-optimised, with considerable potential in hand to improve both recovery and acid consumption.
“Planning for a second phase of metallurgical work is underway to outline preliminary economic parameters such as optimisation of the acid consumption rate, leach response from various sample depths & locations, impurity removal metrics and selection of a preliminary flowsheet,” he said.
“Concurrently, we are awaiting the processed results from the recently flown aerial magnetic and radiometric surveys which we anticipate will assist in identifying our next generation of primary carbonatite targets that we are aiming to drill test as soon as possible.
“Only a small fraction of the extensive 1,300km2 tenement package at Paddys Well has been explored and the “Critical Minerals” prospectivity is very high due to the attractive geology. The next phase of target generation is currently underway ahead of the next drill campaign where our focus is on primary REEs and niobium (carbonatites), and also copper & nickel sulphides.”
Forward plan
An airborne geophysical survey has also been completed over Paddy’s Well, with processed data expected before the end of August, and exploration for priority carbonatites targeting rare earth and niobium will now get underway, including field reconnaissance, soil surveys and rock chip sampling.
