Process for improving leaching rate of germanium in germanium-containing secondary zinc oxide

The invention relates to a process for improving the leaching rate of germanium in germanium-containing secondary zinc oxide, and belongs to the technical field of hydrometallurgy. The method comprises the following six main steps: (1) grinding and slurrying germanium-containing secondary zinc oxide smoke dust, (2) leaching germanium-containing secondary zinc oxide subjected to slurrying with a medium-low acid, (3) enriching germanium in leached clear liquid, (4) oxidizing germanium-poor liquid to precipitate iron, (5) returning part of precipitated iron underflow to the low-acid mixed leaching, and (6) carrying out high-acid leaching on low-acid leached residues. And enabling insoluble sulfides in the germanium-containing secondary zinc oxide to react with iron in the iron precipitation underflow to enter the solution. Aiming at the problem of low leaching rate of the traditional two-stage countercurrent leaching process flow, the germanium leaching rate is effectively improved by adjusting the process and c