Duke Exploration Ltd (ASX:DEX) has fielded positive results from metallurgical test-work on copper mineralisation from the Bundarra Project in Queensland, producing a copper concentrate of more than 25% purity with recoveries in excess of 92%.
All four composites tested returned close to target copper grades, with very low undesirable element concentrations (arsenic, cadmium, chlorine, fluorine and mercury) and negligible gold and platinum-group-element values, although silver was at payable levels of more than 30 parts per million.
In addition, ore sorting tests increased copper feed grades by 174%, resulting in a 97.3% copper recovery rate.
Duke says results from mineralogical studies have indicated further improvements to copper concentrate grade and recovery are practical with tradition, low-risk techniques.
Metallurgic results deliver for DEX
“We are excited to receive these Mount Flora metallurgical results. Impressive flotation characteristics are indicated and clearly supported by a chalcopyrite-dominant copper mineral species,” Duke Exploration managing director Phillip Condon said.
“Copper recoveries and concentrate grades are very good along with a relatively coarse grind size and no significant levels of any deleterious elements showing up at this stage provide a very solid start.
“Future work will explore further improvement and refinement of these results should be straightforward given the indications we have from this initial phase.
“At this juncture all indications with this work are very encouraging and we are enthusiastic to move on to the next phase of testing when appropriate including other resource targets that we will be developing at Bundarra.”
As stated by Condon, DEX is particularly pleased with the primary copper mineral – chalcopyrite – revealed in its testing, as this type of copper is ‘very well’ liberated from ore at relatively coarse grind sizes, which will potentially reduce the proposed processing plant’s footprint and production costs.