Study on the bio-passivation of copper sulfide tailings combined with solid waste to inhibit acidic mine drainage

Acid mine drainage (AMD) refers to industrial wastewater with low pH and high concentrations of metals or metalloids and sulfates, which seriously threatens the ecological environment. To suppress the generation of acidic wastewater from copper sulfide mine tailings at source and ensure the green and high-quality development of mineral resources, this paper adopted a green and efficient microbial process to investigate the bio-passivation treatment of copper sulfide mine tailings by Acidithiobacillus ferrooxidans. Additionally, experiments were conducted to solidify the bio-passivation layer using suspensions formed by 7 g/L fly ash and 9 g/L red mud solid waste as curing reagents. The results showed that the surface of the 5 g tailings passivated by microorganisms produced a passivation layer material (jarosite) of 2.545 g. After leaching tests, the passivation layer was dissolved, and its iron content was reduced from 36.1 % to 23.0 %. In contrast, the iron content of the tailings surface after curing treatment with fly ash and red mud was 37.1 % and 35.9 %. Combined with column experiments, the practical application of bio-passivation in conjunction with solid waste treatment process was explored. It further demonstrated the enormous application potential of applying Acidithiobacillus ferrooxidans for bio-passivation followed by integrated solid waste curing to treat AMD.