Leaching performance of germanium in zinc oxide dust
The content of germanium was high in leaching residue of zinc oxide dust,which leads to the low leaching rate of germanium.Aimed to that problem,the leaching performance of germanium containing zinc oxide dust from different dust catcher,and the relationship of the germanium,iron,silicon in the sulfuric acid leaching process were investigated.The leaching behavior of germanium,the occurrence state of germanium in the residue were investigated,and revealed the reason of further leaching of germanium which is difficult to leach.On this basis,the cascade strengthened leaching with sulfuric acid,hydrochloric acid,hydrofluoric acid to the leaching residue of zinc oxide dust were carried on.The results show that germanium mainly exists in the silicate and insoluble solid in the mixture of zinc oxide dust,in particular,the boiler-dust contains more zinc ferrite and silicate,which is difficult to dissolve germanium.It is key of the iron and silicon content in dust to suppressed the promotion of germanium leaching rate.Insoluble germanium mainly exists in the undissolved silicate minerals and insoluble solid in the residue.The key of leaching germanium is silicate dissociation.Under the sulfuric acid system,the recovery rate of germanium is further improved,through leaching the mineral containing zinc ferrite and silicon under high temperature and high acid,and controlling leaching and precipitation behavior of silicon in process.