Study On The Process Of Extracting Germanium From Sulphate Zinc Solution

In order to extract germanium from acid leaching liquor of zinc replacement slag by hydrometallurgical extraction process, the synergistic extraction mechanism of germanium with P₂04+YW100 and N₂35+YW₁00 separately and the extracting condition and the selectivity of stripping agent and the effects on stripping process were studied. The method of preparation germanium concentrate from germanium-enriched liquor was also studied. On the base of optimum condition of germanium extraction, the scale-up experiment was conducted. According to the results of commercial test, the stability of YW100 in zinc leaching liquor was given profound investigation and the comprehension experiment was also conducted with new extraction germanium process by using highly active stripping agent (AN).The results have shown that the synergistic extraction system with P₂04+YW₁00 had significant positive synergistic extraction effects, it can adopt to extract germanium from high acidity liquor (PH<0.5). By using P₂04+1.25%YW₁00 as synergism and O/A=1/4, the extraction recovery of germanium from industrial zinc leaching liquor was reach to 96% under room temperature and 5 minutes late after operation. HF, NaOH, NH4OH, AN and many other chemical reagent can be choose as stripping agent of germanium from loaded organic phase. Considering the stripping recovery and stability of posterior working operation and organic phase, the best results can be obtained with AN as stripping agent. Using AN (concentration is 27g/l) as stripping agent and O/A=4/1, stripping loaded organic phase (Ge concentration is 0.47g/l), the stripping recovery of Ge was 98.4% and only about 1.85g/l Ge was in stripping liquor. The germanium concentration (Ge>25%) obtained in hydrolytic sediment after evaporation.Germanium cannot be extracted in acid liquor with unity N₂35. Using N₂35+YW₁00 as synergism, germanium can well be extracted from acid liquor with complexing agent and high extraction recoverycan be obtained in weakly acidic leaching liquor (PH>1.5). The extraction recovery can also be promoted if temperature was raised and O/A was enlarged and PH was increased. By using 20% N235+1.5%YW100+10%OctOH-2+Amsco as synergism and the weight of tartaric acid, which is 30 times than that of germanium, was added in acid leaching liquor to complexation and O/A=l/3, the extraction recovery was reach to 84% under room temperature and 5 minutes late after operation and stripping loaded organic phase with 4mol/lNaOH, one stage extraction recovery was 98.3%under optimum processes conditions and there was about 0.2g/l Ge in stripping liquor.Compared with other organic systems, the P2O4+YWIOO was the best system to extract germanium from acid leaching liquor of zinc replacement slag.From the commercial experiment and improved new process with P2O4+YWIOO as synergism to extract germanium, the results shown that YW100 had good solubility and hydrolytic in acid liquor and cannot be recovery if destructed in extraction process. If the potencies of the synergism to extract germanium were to be kept, the YW100 must be added to re-circulated synergism. In order to reduce YW100 consumption, new process must be adopted with multi-stage cross flow extraction and contentious adding YW100 and AN. After 5-stages cross flow extractions, the organic phase was stripped with AN and the organic re-circulated, the extraction recovery was over 95% per pass and the stripping recovery was more than 99% each run.The results showed that with the new process germanium has high extraction recovery and high striping recovery and enrichment ratio of germanium and the unite consumption of primary material and auxiliary materials reduced to 16% compared with traditional extraction process, the new process has good adaptation to recovery germanium and can be continuous operated steadily and used to commercial run.