This post is mainly waffle that I wrote to amuse myself on a cold and rainy day. All the information is courtesy of Google's search engine.
On the matter of R&D activity in respect to alumina, Alcoa has been doing that for a hundred years, but as there was no market for better-than-smelter-grade alumina until very recently, Alcoa stuck with the cheapest process, the Bayer Process. Alcoa did not research all the significant processes researched in that period, but it knew about those that it did not research – see see https://www.cairn.info/revue-cahiers-d-histoire-de-l-aluminium-2013-2-page-42.htm
There is a table in that document that lists 18 alumina-extraction processes for clay ores, two for anorthosite (feldspar hard rock), and the Bayer Process for for bauxite. You can see that the the costs of the last mentioned undercut alternatives, except for the two lime soda options. Lime soda is essentially calcium hydroxide (94% calcium hydroxide, 5% sodium hydroxide, and less than 0.1% potassium hydroxide. That process may have problems, otherwise the Bayer Process would not be so prominent.I paste that table below.
However, for HPA, I understand that the Bayer Process is not good enough, because the contaminants that remain are too high a percentage for HPA.
Soon after the Alcoa-JV and all the hopefuls are ready to ship HPA, there is a risk that the price drops to take the super-profit off the table, but Alcoa can live with that if it seizes a dominant position quickly.
Zeolite coatings of battery separators are worth a thought, and the main ingredients to make zeolite ares alumina and silica. Kaolinite can be used as a source material, which could make Cadoux relevant.
