Biowaste-based biodegradable flocculants for clean and sustainable tailings management in industrial mining and mineral processing

Massive fluid tailings discharged from industrial mining and mineral processing operations pose numerous economic and environmental challenges. To remove water and condense tailings into sediment, we developed a novel bioflocculant from specified risk materials, a particular type of waste biomass from the animal rendering industry. By properly controlling key synthesis conditions, the bioflocculant successfully met industrial requirements for fluid tailings treatment, including enhanced short-term tailings settling and improved ultimate water removal extent. Settling tests using real industrial fluid tailings showed that the synthesized bioflocculant enabled an initial settling rate 4 magnitudes higher than the control case and achieved 93.2% the dewatering efficiency of a commercial flocculant (hydrolyzed polyacrylamide; HPAM). In contrast to HPAM, our bioflocculant can achieve tailings settling without gypsum, a common processing aid that can hinder downstream industrial operations. More importantly, growth tests using two common microorganisms (Saccharomyces cerevisiae and Escherichia coli) suggested that the bioflocculant can be easily degraded, indicating reduced negative environmental impacts after its use. Taken together, this study demonstrates the great potential of implementing a biodegradable bioflocculant from proteinaceous wastes for clean and sustainable management of mining and mineral processing fluid tailings.