Germanium recovery from the neutralization sludge of chlorinated lime by hydrometallurgical process

This paper studies a germanium recovery process from neutralization sludge of chlorinated lime: using hot water to wash away calcium first,next leaching germanium with dilute hydrochloric acid and removing calcium,from the sludge obtained thereby using a two-stage countercurrent alkaline leaching process to leach Ge,after that,mixing acid leaching solution and alkaline leaching solution,adjusting the pH to 2~2.5,and using extract to precipite germanium,finally roasting the precipitated sludge and the Ge concentrate is obtained thereby.For the Ge concentrate obtained by this process,the germanium recovery can reach above 90%.