Abstract: Gallium (Ga), germanium (Ge), and indium (In) are rare dispersed strategic metal elements that are difficult to extract due to their lack of independent mineral deposits and low natural abundance. However, because of their affinities for iron and sulfur, Ga, Ge, and In are commonly associated with sphalerite and other sulfide minerals. During pyrometallurgical or hydrometallurgical zinc processing, trace amounts of these elements become enriched and remain in the slag. In this study, zinc electric furnace slag with relatively high contents of Ga, Ge, and In was used as the raw material. The leaching behavior of Ga, Ge, and In was investigated under various leaching systems (sulfuric acid and hydrochloric acid systems) by examining the effects of temperature, acid concentration, oxidant type, and oxidant dosage. The results showed that Ga, Ge, and In achieved leaching rates of 97.51%, 94.58%, and 98.73%, respectively, in the optimized two-stage hydrochloric acid oxidation leaching process. Furthermore, XRD and SEM analyses revealed that the high lead content in the raw material led to the formation of insoluble lead sulfate in the sulfuric acid system, which encapsulated the particles and inhibited the leaching of Ga, Ge, and In. In contrast, in the hydrochloric acid system, lead chloride forms coordination complex reactions, which redissolve the precipitated lead chloride. This effect effectively eliminates the particle encapsulation barrier and realizes the efficient and synchronous leaching of Ga, Ge, and In, providing a feasible technical route for the extraction and utilization of scattered metals.der complexation, leading to the dissolution of lead species and effectively preventing encapsulation. As a result, efficient and simultaneous leaching of Ga, Ge, and In was achieved, providing a promising approach for the extraction of these strategic metals from zinc smelting residue

Key words: Zinc electric furnace slag, Gallium, Germanium and Indium, Sulfuric acid oxidation leaching, Hydrochloric acid oxidative leaching.