China Nonferrous Metallurgy

Black shale stands as a strategically vital mineral resource across China, distinguished by vast reserves and extensive geographical distribution. These geological formations encapsulate critical rare metals—vanadium, nickel, and molybdenum—yet remain substantially untapped due to subeconomic grades and complex metallogenic characteristics. Bioleaching emerges as a transformative extraction technology, wherein heap bioleaching processes demonstrate compelling advantages for shale resource development through operational scalability, minimized energy expenditure, and reduced ecological impact. In this study, three groups of bioleaching bacteria with distinct temperature adaptabilities (mesophilic mixed bacteria, moderate thermophilic mixed bacteria and thermophilic mixed bacteria) were selected to conduct systematic bioleaching experiments for vanadium, nickel and molybdenum from black shale. The primary conclusions are summarized as follows. All consortia exhibited pronounced efficacy in extracting vanadium (57%~74%) and nickel (83%~88%) from black shale matrices. The leaching percentage of molybdenum is relatively low: while the thermophilic consortium achieved merely 1%~5% extraction, mesophilic and moderate thermophilic variants attained 10%~20%. Subsequent designation of the mesophilic consortium as the optimized biological extractor enabled high-throughput genomic analysis, revealing functional dominance by Leptospirillum ferriphilum and Acidithiobacillus spp. , after domestication, the proportion of Acidithiobacillus spp. increased. These taxa demonstrated synergistic roles in iron/sulfur oxidation critical to metal solubilization. At present, the metal leaching efficiencies of black shale via bioleaching remain lower than those of other technologies, and the leaching performance of molybdenum is unsatisfactory. Further research should focus on the synergistic effects among microorganisms, the coupling relationship between temperature-adapted microorganisms and the temperature field in heap leaching, as well as the bioleaching mechanism. This work is expected to provide theoretical basis and technical support for the efficient and green bio-extraction of vanadium, nickel and molybdenum from black shale.