Technology status and research progress of zinc bioleaching

Zinc is a nonferrous metal necessary for modern industry and an important strategic resource. It ranks fourth among all metals in terms of world production after iron, aluminum, and copper. Zinc sulfide ore is the most important zinc-producing mineral in the world, followed by associated zinc oxide ore and zinc-containing secondary resources. China is rich in zinc resources. Most of China’s lead–zinc and copper–zinc deposits are mainly lead–zinc integrated deposits, lead–zinc sulfide deposits, and other associated components. These types of mineral resources lead to wastage of resources in the development and utilization processes and affect the subsequent smelting process, which places considerable pressure on the production efficiency and ecological environment. The current mining and metallurgical industry vigorously promotes industrial development and has shifted in the favor of recycling, low-carbon, and green technologies. The biological leaching technology, as a green and low-carbon wet metallurgy technology, meets the current environmental protection policy requirements. This technology uses microorganisms and their metabolites to soak valuable metals in ores and has many advantages such as simple process, environmental protection, and capability to process low-grade ores. With the development of hydrometallurgical technology, the biological leaching technology of zinc from various types of low-grade zinc resources has attracted researchers’ attention and shown considerable application potential. First, this study introduced the mineral characteristics of zinc resources and analyzed their bioleachability. Then, the bioleaching process of zinc was summarized, and the leaching bacteria, electrochemistry, thermodynamics, kinetics, and leaching mechanism were systemically introduced. Furthermore, the current situation and/or progress of zinc bioleaching technology were generalized. Finally, the development trend of zinc bioleaching process and future research hotspots were considered. This study shows that the breeding of highly efficient bioleaching bacteria and the corresponding technology and equipment inventions are the current research hotspots and can also be the development directions for zinc bioleaching in the future. This will help ensure rapid and effective development of the zinc bioleaching technology.