Extracting iron from Red Mud by use of hydrogen

Meet Dr. Ahmad Hassanzadeh! He endeavours to discover a sustainable, cost-effective, and environmentally friendly approach for extracting iron (Fe) as well as titanium, copper, scandium and rare earth elements (Ti, Cu, Sc and REEs) from the red mud which is waste from the Al industry.

It is estimated that the global aluminium consumption will increase from 65.87 million metric tonnes in 2022 to 78.40 million metric tonnes in 2029. This has also a direct impact on increasing CO2 level which is predicted to be around 700 ppm in 2040. This can significantly be diminished by substituting H2 as a reductant instead of using carbon in metal production.

Ahmad works in the Department of Geo-science and Petroleum Engineering at NTNU to selectively separate magnetite from the H2-reduced bauxite residue.

Ahmad Hassanzadeh characterizes mineral properties through conventional analytical techniques and automated mineralogy to determine the mineral compositions of the H2-reduced samples. This technique, which is based on coupling Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS or EDX), also provides detailed and accurate information on the mineral content in the samples.

Advanced characterisation methods are essential to understand details in all processes steps which is needed to be able to utilize valuables in waste streams from the aluminium industry (Red Mud).

Ahmad utilizes low and intermediate magnetic separators operating in both dry and wet environments as well as various gravitational techniques to separate magnetite produced from the waste Red Mud by use of hydrogen. Magnetite is finely disseminated throughout the samples. Separation of magnetite is a long-standing challenge in the mining and mineral processing industries. Ahmad hopes to introduce his method to the current 100 existing plants across the world to, not only vaporize the overall approximate waste of ca 300 million tonnes, but also gain ca. 30-40% of iron (Fe) and other critical elements.           

Through this work, Ahmad hopes to mitigate water pollution induced by collapsing red mud tailings dams and mortalities. E.g., in Hungary, Ajka red mud depository in 2010 led to disposing 1 million m3 alkaline slurry to the environment and 10 deaths and over 120 injuries. A similar tragedy was taken place in 2015 in China’s Guangdong Province composed of 2 million m3 of red mud slurry.

Ahmad is genially grateful to Przemyslaw B. Kowalczuk for giving him the opportunity to work on this project and very thankful to the head of engineers Camilo Mena Silva, and Kornel Mateusz Tobiczyk, as well as Stefanie Lode, Gustav Ward, and Henning Leonard Nygård Aune for their continuous assistance.

References:

Worldwide aluminum consumption forecast 2029 | Statista

Red mud – Wikipedia

Aluminum in February 2022 (amazonaws.com)