Overview
Topic status: Completed
Overview
The Bayer process has an insoluble residue that is separated from a supersaturated sodium aluminate solution and aluminium is recrystallised from the supersaturated sodium aluminate solution in the form of gibbsite.
This study focuses on the solid liquid separation (SLS) process that occurs post-digestion and prior to the crystallisation process. The SLS process removes the insoluble residue from the supersaturated sodium aluminate solution. Due to the solution supersaturation, during the SLS process there is a tendency for some aluminium (gibbsite) to precipitate, which causes unwanted scaling problems and a loss in alumina production. Calcium hydroxide can help stabilise the supersaturated solution during SLS and minimise scaling, however, calcium hydroxide can react with aluminate forming tri-calcium aluminate, which results in a production loss.
This research will focus on identifying other calcium sources for reducing scaling without effecting production. A full characterisation on the scale that forms and resultant scales after different calcium sources will be analysed for the type of mineralogical phases that form and how easily these scales can be removed. Students working on this project will coordinate tests with Rio Tinto Alcan.
- Study level
- PhD, Masters, Honours
- Supervisors
- QUT
- Organisational unit
Science and Engineering Faculty
- Research area
- Keywords
- alumina, aluminium, industry
- Contact
- Please contact the supervisor for enquiries.
Dr Sara Couperthwaite
Professor Godwin Ayoko
Emeritus Professor Ray Frost
