High Temperature Processing Options For The Valorisation Of Bauxite Residue Towards New Materials

Tobias Hertel, Bart Blanpain, Yiannis Pontikes
2017 Zenodo  
The paper describes different processing schemes to transform bauxite residue (BR) into new binders for building applications, while recovering, depending on the chosen route, base metals. The flow chart consists of several unit operations. The first step is the chemical modification, by mixing BR with additives, such as C, SiO2, and/or B2O3. Different blends are sintered or vitrified at temperatures ranging from 900 to 1200 °C. When silica and carbon are added, typically a semi-vitreous slag
more » ... generated, which can be either alkali-activated or used as a pozzolana in blended cements. Upon addition of B2O3, C and SiO2, the formation of easy to recover metallic Fe is observed, while the Fe-depleted slag is a highly reactive precursor for an alkali-activated binder. The suggested options have been tested and demonstrated successfully at a laboratory scale. In order to evaluate the feasibility in a closer to real-life scenario, an upscaling pilot-plant project has been launched. This also contributes to a precise and realistic environmental and economic assessment, which is essential before commencing industrial implementation.
doi:10.5281/zenodo.1241063 fatcat:zrkubghth5dqxfauyjsw7rqvpa