Empire Metals Ltd (AIM:EEE) has confirmed the titanium dioxide mineral deposit recently discovered at Pitfield in Western Australia is a high-purity anatase deposit suitable for valuable commercial projects.
In a statement, Empire said the discovery, which lies within the near-surface, strongly weathered "saprolite" cap covering all the 40km long, titanium-rich mineral system at Pitfield, is enriched with high-purity anatase formed from the weathering of the original titanite-rich, bedded sediments.
Mineralogical assessment of the strongly weathered sandstones indicates an abundance of high-quality anatase, containing up to 98.5% TiO2.
Anatase also accounts for more than 5% of the mass of the near-surface weathered bedrock or four to five times higher TiO2 concentration than that typically found in mineral sand deposits.
Anatase, a variant of rutile, is considered a highly valuable strategic feedstock for the titanium chloride pigment and titanium metal markets as rutile-rich resources decline globally.
“Importantly, it is the purity and TiO2 content of the feedstock and not the specific TiO2 mineral (rutile vs anatase) that is most important to producing a high-value TiO2 pigment or metal product,” Empire added.
Pitfield represents a different, previously unrecognized class of sandstone-hosted titanium deposit that contains none of the deleterious elements associated with other, carbonatite-hosted, titanium deposits.
Most of the titanium in the soft, friable, weathered sandstone bedrock is contained within the easily extractable, naturally heavy anatase meaning a potentially simpler mineral separation process.
Shaun Bunn, Empire’s managing director, said: "The discovery of a naturally occurring, concentrated zone of high-quality anatase within the extensive weathered cap provides an enormous opportunity for the company to accelerate its plans.
"The anatase found at Pitfield has a very high TiO2 content and is free of deleterious impurities, making it a desirable feedstock for processing to TiO2 pigment.
“Anatase can be chlorinated to produce titanium tetrachloride (TiCl4) under similar conditions required to process rutile, an important precursor to making TiO2 pigment and titanium metal.
"Clearly, this discovery will have a material and immediate positive impact on the overall project economics.
“The strongly weathered cap can be mined first and will be amenable to very low-cost strip mining methods due to its surficial position, broad extent and soft, friable nature due to weathering.
"The weathering has also converted the gangue silicate minerals to kaolinite and quartz, common minerals that can be simply separated with conventional techniques, providing a clear processing pathway for the recovery of a high-grade TiO2 mineral concentrate."