| Abstract Scope |
There are abundant strategic rare scattered metal resources in lead and zinc deposits in China, especially zinc resources in Yunnan province, which are associated with indium (In), selenium (Se) and tellurium (Te), etc. The rare scattered metal ions with low valence dissolved into zinc leaching solution, and are difficult to remove by conventional zinc powder replacement method. They were enriched in the ZnSO4 solution, which caused serious problem to zinc electrowinning process such as hydrogen generation, zinc re-dissolution, plate burning, and low current efficiency, etc. So, they needed to be deeply removed from ZnSO4 solution. This article used ozone, a powerful oxidizing agent, to oxide the trace rare scattered metal impurities with low valence into higher valence and then occurred hydrolysis precipitation into sludge. The mass transfer characteristics between ozone and impurities in ZnSO4 solution was investigated. Effects of reaction temperature, ozone flow rate, and residence time on overall volumetric mass transfer coefficient (kLa) were studied. Furthermore, correlations relating kLa to the experimental parameters were also reported, and a gas-liquid mass transfer model was developed. |