| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Alumina and Bauxite
|
| Presentation Title |
Inhibition of Kaolinite Dissolution in Bayer Liquor Through Addition of Lithium |
| Author(s) |
Horace OGilvie, James Vaughan, Hong (Marco) Peng |
| On-Site Speaker (Planned) |
Horace OGilvie |
| Abstract Scope |
With increasing reactive silica in bauxite, sodium hydroxide usage increases due to the precipitation of desilication products in the Bayer process. In this study, we report on how the presence of lithium ions in the Bayer liquor inhibits the dissolution of kaolinite. The inhibition was studied at temperatures ranging from 90-150°C with residence times up to 4 hours. The inhibition effect is attributed to the localised precipitation of LiAl(OH)7.2H2O on the surface of kaolinite. This phenomenon enables a low temperature digestion process to be contemplated, whereby gibbsite is selectively dissolved in the presence of kaolinite, leading to significant savings in sodium hydroxide as well as a low-alkaline bauxite residue. Economic trade-offs between lithium addition rates and sodium hydroxide savings are discussed. |
| Proceedings Inclusion? |
Planned: Light Metals |