Ann: Investor Presentation, page-18

HPA is high purity alumina, not aluminium, ie aluminium oxide. It has a range of electronic uses because it is an excellent insulator.

I suspect it has come about due to the influence of Boyd Willis, who also works for Collerina Cobalt (ASX:CLL). Boyd has apparently developed a process for recovery of the aluminium dissolved into solution in the HPAL process when they are leached in sulphuric acid. CLL have switched from a HPAL feed to the HPA First process, which uses a different feed than a nickel-cobalt-scandium ore.

So I guess he has decided to do the same with PGM and offer the technology to them as well. My suspicion is that it uses a solvent extraction process to extract aluminium into an organic liquid that is then re-extracted into a different solution which has its pH adjusted to produced aluminium hydroxide that is then calcined to alumina. The trick is getting the high purity 99.99% plus.

Altech are also planning on making HPA, but probably via a different process.