Bioleaching metal-bearing wastes and by-products for resource recovery: a review

Abstract

The global transition to a circular economy calls for research and development on technologies facilitating sustainable resource recovery from wastes and by-products. Metal-bearing materials, including electronic wastes, tailings, and metallurgical by-products, are increasingly viewed as valuable resources, with some possessing comparable or superior quality to natural ores. Bioleaching, an eco-friendly and cost-effective alternative to conventional hydrometallurgical and pyrometallurgical methods, uses microorganisms and their metabolites to extract metals from unwanted metal-bearing materials. The performance of bioleaching is influenced by pH, solid concentration, energy source, agitation rate, irrigation rate, aeration rate, and inoculum concentration. Optimizing these parameters improves yields and encourages the wider application of bioleaching. Here, we review the microbial diversity and specific mechanisms of bioleaching for metal recovery. We describe the current operations and approaches of bioleaching at various scales and summarise the influence of a broad range of operational parameters. Finally, we address the primary challenges in scaling up bioleaching applications and propose an optimisation strategy for future bioleaching research.

From Genes to Bioleaching: Unraveling Sulfur Metabolism in Acidithiobacillus Genus

“…A. ferrooxidans originally emerged as the acidophile model microorganism due to its applications in copper biomining [ 45 ], and several multi-omic approaches have been carried out in recent years to study its genetic makeup [ 46 , 47 , 48 , 49 ]. However, recent studies have underscored the significance of other species, such as A. thiooxidans , as noteworthy workhorses in the industrial extraction of a diverse range of metals including Cu, Ni, Zn, and Co from different ores and residues [ 44 , 50 , 51 ]. Biomining technologies typically operate under extremely acidic conditions with pH levels between 1.5 and 2.5 [ 52 , 53 ], and certain bioleaching approaches (e.g., Monywa (Myanmar)) operate at pH levels below 1.2 [ 54 ], which can impact Acidithobacillus growth and leaching rates [ 53 , 55 ].…”

Discarded e-waste/printed circuit boards: a review of their recent methods of disassembly, sorting and environmental implications

“…Meeting the continuously growing demand for metals has become a challenging task due to the declining quality of ore sources [10,11]. Certain metals such as rare earth elements, Li, Co, Cu, Sn Zn, Al and Fe amongst others are categorised as critical metals owing to their supply vulnerabilities and substantial economic significance [12,13]. In the past decade, materials containing metals at the end of their useful life, often referred to as metal-bearing wastes, have gained widespread recognition as secondary resources for critical raw materials.…”