Australia Minerals and Mining Group (AMMG) has successfully produced 99.99% (4N) HPA (high purity alumina) using its own innovative aluminous clay (kaolin) to HPA processing technology. AMMG filed three patent applications for the aforementioned processing technology in February 2013. AMMG produced the 4N HPA from its unique processing technology in collaboration with its consulting processing chemists, TSW Analytical. TSW was engaged in mid-2012 to refine and verify AMMG’s process and produce HPA material using that process.

Ric Dawson, AMMG’s Managing Director, said “After producing >99.9% HPA, we conducted additional trials to subsequently achieve the 4N HPA. We are now confident from TSW’s work that we will be able to produce higher 5N or 6N purity levels, subject to further successful development of the process. We are now reviewing the next steps to progress this project and are scoping the design, construction and financing options for a HPA production plant.”

AMMG’s process is favoured by the unique mineralogy of its aluminous clay material, which contains extremely low levels of impurities, such as iron and titanium. The company’s aluminous clay deposits are hosted by the Yilgarn Craton, Western Australia, which is one of the oldest weathered cratons on earth. The ancient weathering has left the aluminous clay as a primary or in-situ resource; it is whitish in colour and extends from the surface to a reported depth of 42 m.

The company’s 100% owned South West HPA project carries a combined JORC resource of 297 Mt of aluminous clay – currently the second largest reported aluminous clay deposit in the world. HPA refers to alumina that has a purity level of more than 99.99% (4N). It is a premium high end product that is used in a number of applications such as high-performance electronics; tablet, smartphone and computer screen backlighting; LED’s; and hybrid cars. It is a specialised alumina that is used for its superior hardness, high brightness, inertness (non-conductive), superior corrosion resistance and its ability to withstand extreme temperatures.

While HPA is used in a variety of markets, it is reported that about 60% of HPA is designated to the LED industry. Reported worldwide production of HPA is estimated at 15,000 t/y, which is expected to increase at 7% CAGR.