| Abstract Scope |
Bauxite Residue (BR) presents a significant challenge in the aluminum industry due to its large volume. This poses problems because of the limited storage space available around the refineries and the necessity to comply with environmental regulations.
Innord Inc., the R&D subsidiary of Geomega Resources Inc., has developed and is scaling up a sustainable multi-step process for reducing the volume of BR by valorizing its main components, such as aluminum, sodium, iron, and silicon. Moreover, the proposed process extracts and recovers critical metals such as titanium and rare earth concentrate. The proposed flowsheet includes three main circuits called C1, C2, and C3. The main reagents are regenerated and recycled in each circuit to avoid any effluent. This process has been successfully tested on several different BR samples at a bench scale.
This paper presents pilot-scale test work on two distinct BR samples processed through the C1 treatment to extract and recover caustic soda, calcite, reactive alumina, and silica. A volume reduction of over 55 % was achieved, and the process economy is favorable because several marketable off-take streams, including Smelter Grade Alumina (SGA), caustic soda, and cement grade silica, are produced. Therefore, a Techno-Economic Analysis (TEA) is provided. |