High Purity Alumina – Current and Future Production

ABSTRACT

This paper provides and overview of current and emerging processes to produce high purity alumina, HPA. Strong demand for HPA is projected to continue for the coming decade at least, driven by its critical role in the manufacture of LEDs and Li-Ion battery separators which require 4N (99.99% Al₂O₃) purity. The current selling price of 4N HPA is over $20,000/t. Most HPA is currently produced from high purity aluminum, a very expensive feedstock. Under these conditions there is considerable interest in new production from lower cost starting materials, including SGA, Bayer process ‘hydrate’, alumino-silicate clays, and other aluminous minerals.

KEYWORDS:

• High purity alumina
• manufacture
• review

Disclosure of potential conflicts of interest

No potential conflict of interest was reported by the author(s).

Notes

1. This schematic (and all subsequent ones) developed by the authors from various sources.

2. The effectiveness of HPA as a promoter suggests that its role is to provide nucleation sites rather than to act as a template for growth.

3. AACH is the ammonium analogue of the mineral dawsonite sometimes seen in Bayer process red mud carbonation products.

4. A good review of the Sumitomo variation is referenced in Table 3.