Australia Minerals & Mining Group (AMMG) has filed a new patent application with the Australian Patent Office for its acid-based alumina processing technology.
The patent application relates to AMMG’s acid-based processing technology, which produces alumina from its aluminous clay material with purity levels greater than 99.95% purity (HPA).
The processing technology developed by AMMG uses a low-energy input, its reagents are recyclable. AMMG’s aluminous clay material is a low impurity feedstock and has relatively high alumina levels (screened grade up to 38% Al2O3).
AMMG’s Managing Director, Ric Dawson said “With the patent application, AMMG has the confidence to advance its commercialisation strategy, which involves determining the optimised location and potential construction of a HPA pilot plant facility.
“After the successful production of greater than 99.9% HPA using our process, AMMG will now build on advancing the level of interest we have received to date from around the world.”
The Yilgarn Craton, which hosts the AMMGs aluminous clay projects, is one of the oldest weathered cratons on earth.
The weathered granites have left the residual aluminous clay so that the deposits are ‘primary’ or ‘in situ’ in nature, as opposed to those that are secondary in nature where the aluminous clay has been transported by water and then deposited in typically smaller and narrower deposits or lenses at the bottom of ancient lakes and rivers.
The ancient weathering process has also resulted in extremely low levels of impurities (such as iron and titanium); the aluminous clay is whitish in colour extending from surface to a reported depth of 42 metres.
High Purity Alumina (HPA) refers to alumina that has a purity level of more than 99.99% (4N). It is a premium high-value product that is used in a number of applications such as high-performance electronics; tablets, mobile phones, computer screen backlighting; LED’s; and hybrid cars.
Due to its ascendant physical and chemical properties, HPA is used for its heat resistance, electrical isolation, abrasion resistance and corrosion resistance.
HPA is used in coatings for a separator that improves the safety of lithium-ion secondary batteries as well as for battery electrodes.
It is used in the automotive sensor applications as an alumina substrate, which is used for its excellent electrical insulating properties and high heat conductivity.
Due to HPA’s high level of plasma corrosion resistance, it is used in semiconductor applications.
HPA ranges from about US$141,000 per tonne to US$396,000 per tonne depending on the purity and particle size.
Based on industry reports, worldwide production of HPA is about 15,000tpa. This figure is expected to rise at approximately 7% CAGR, primarily driven by the rising LED market demand.