Empire Metals Ltd (AIM:EEE) said metallurgical gravity test work on anatase-rich weathered cap samples from its Pitfield project in Western Australia produced a heavy mineral concentrate.
The recoveries of titanium and iron were 80% and 92%, respectively. Importantly, said Empire, the rejection of aluminium and silica minerals was also high.
Empire discovered the high-purity anatase mineralisation within a near-surface, strongly weathered "saprolite" cap zones that it now estimates run from near surface to depths of around 60 metres or double previous indications.
Preliminary froth flotation test work on the weathered samples has also been positive, it said, while slighter rougher tests produced a concentrate containing 78% of the TiO2-bearing minerals with a rougher concentrate grade of 8.8% TiO2.
“This combination of gravity and flotation mineral separation techniques shows significant promise as a processing route for firstly producing a heavy mineral concentrate, and then for further mineral separation stages to separate and recover the TiO2 bearing minerals into a high-grade, high-purity concentrate,” added Empire.
Development of a processing flowsheet will continue through the first half of 2025 with Empire considering a lower capital and operating cost option for a continuous pilot plant facility utilising the anatase mineralisation in near-surface weathered cap.
Shaun Bunn, managing director, commented: " During the testwork there was a clear visual difference between products coming off the table, indicating separation of heavy, dark coloured minerals from the lighter coloured gangue minerals.
“This has been confirmed by the assay results indicating high recovery of titanium and iron, and high rejection of aluminium and silica.
“The next phase of the testwork programme, using samples from the recent drilling programme, will focus on unit processes to separate the iron oxide minerals from the titanium oxide and titanium-iron-oxide minerals to produce a high-grade TiO2 mineral concentrate.
"We have also now received the geochemical analysis results for the recently completed diamond core drilling programme which have identified extensive, high-grade TiO2 weathered zones from very near surface to depths of around 60 metres, nearly double that previously encountered at the Cosgrove and Thomas prospects."