Bayer red mud (RM) is a solid residue generated by alumina refinery. Now there are over 300 million metric tonnes RM piling up in China. The disposal of RM is an urgent and complicated problem in the world. The catastrophe of RM dam failure in Hungary is sounding the alarm all the time around us. However, due to the shortage of available technology for RM treatment, stockpiling is the major way for worldwide RM treatment.

To solve the problem and decrease the impacts on environment caused by RM, associate professor Ma Shuhua and her colleagues from Institute of Process Engineering, Chinese Academy of Sciences focused on the RM utilization and achieved a great breakthrough. Based on the fundamental research on the principle of phase transformations in hydro-alkali system, Ma’s group found a suitable way to convert the main phases of RM rich in alkali and alumina into the phases lean in alkali and also alumina if possible.

The content of Na2O in RM dropped from the 10wt% to less than 1wt% and the treated residue was therefore harmless to environment and can be used as raw materials to product cement, glass ceramics, insulation boards etc. Meanwhile, enriched sodium and alumina in the reaction medium could easily return to the Bayer cycle (the technical process of alumina refinery) and these valuable elements were recovered successfully.

The results of this research were published on Journal of Hazardous Materials. More achievements of the research can be found in ICSOBA international bauxite residue seminar, Octorber 2011, Goa, India and Hydrometallurgy.