A Novel Technology Of Germanium Enrichment And Recovery From Zinc Hydrometallurgy Process

In the zinc hydrometallurgy, the scattered metal germanium is the impurities element which badly affects current efficiency during electrolytic process with a great recovery value. Extraction and tannic acid precipitation are widely used for germanium recovery. However, these processes have the common disadvantage of high cost and low recovery rate. In this paper, based on the status of concentration and recovery of germanium from zinc hydrometallurgy process, combination process of neutralization precipitation method and iron powder reduction method was put forward to separate and enrich germanium from the precipitating vitriol supernatant of zinc hydrometallurgy. The main research content and results are as follows:The exploratory experiment of G8315extraction germanium was carried out. It is diffcult for the large-scale application due to the high cost of extractant, although, the experimrntal effect is good. Therefore, the new combination process of neutralization precipitation method and iron powder reduction method were addressed to achieve separate and concentrate germanium from zinc sulfate solution. The optimum conditions were determined for neutralization precipitation method and iron powder reduction method, respectively.The optimum technological conditions of neutralization precipitation process were determined as following:mFe:mGe=40:1,80℃for temperature,5.2for reaction endpoint pH, and100min for the reaction time. Under this condition, the precipitation rate of germanium, copper and iron are more than99.0%,92.0%and nearly100%, respectively. Germanium grade of neutralization dregs after the pretreatment was0.335%, which is about70times in zinc calcine.The optimum technological conditions of iron powder reduction process were determined as following:1.5for reaction initial pH,80℃for temperature,600rpm for stirring speed,4grams per liter of solution for reducing agent, and120min for reaction time. Under this condition, the reduction efficiencies of germanium and copper are more than96.0%and nearly100%, respectively. The solution pH value is4in the end of reaction. The grade of germanium and copper are2.06%and20.89%, respectively, in the reduction product. This process has realized effective separation and concentration of copper and germanium from zinc sulfate solution.The laboratory expanded experiment of iron reduction and concentration germanium confirms the feasibility of this process.The results show that it is feasible to separation and concentration of copper and germanium from the precipitating vitriol supernatant by the combination process of neutralization precipitation method and iron powder reduction method. This process exhibits the advantages of perfect metal separation and concentration. Moreover, it achieves the objectives including the simple operation, low cost, safety and environmental protection.