Study On Extraction Of Indium From Sulfate Solution By Mixed Extraction System

Indium resource is abundant in our country, most of indium is recycled in zinc hydrometallurgy. In general, P204 is used in separation and enrichment of indium from the rich indium sulfate solution, but using hydrochloric acid striping in traditional single P204 extraction system brings a lot of harm to the production and the environment. At the same time, ferric iron accumulation in the organic phase, leads to organic phase poisoning easily. Some studies indicate that mixed extraction system which is comprised by P204 and neutral phosphorus extraction agent can solves the problem in the conventional P204, so indium extraction mechanism of mixed extractant system in sulfuric acid solution, the behavior of indium in the process of extraction is researched in the paper:(1) The comparative research on indium behavior extracted by three kinds of acid phosphorus was finished, the indium extraction ability by a single extractant system:P204> P507> Cyanex272. On the basis of the a single extractant system, extraction mechanism of mixed extractant system, the role of TRPO/TOPO in extraction and the content of extraction was studied by hydrogen ion concentration, TRPO/TOPO extractive sulfuric acid, saturation, infrared spectrum experiment, the results showed that:Joining the neutral phosphorus class extraction agent does not change extraction of compound, extraction of mixed extraction system compound is still in the form of In(P204)3.(3) The dynamics research of single acid extraction and mixed extraction are studied by constant interracial area method, the results show that:when The temperature is 25℃, extracting In3+of P204 organic phase is controlled by diffusion, the process extracting of Fe3+is controlled by interface chemical reaction. Extracting In3+ of P204 and TOPO organic phase is interfacial chemical reaction. The process extracting of Fe3+ is controlled by the interfacial chemical reaction.(4) The influence of the mixing time, acid concentration, concentration of TRPO/TOPO, temperature, ratio of volume and concentration of striping acid was studied to the behavior of indium in the process of mixed extractant system, the results show that:After P204 organic phase add TRPO/TOPO, the impact is not large for the single stage extraction of indium and indium Loaded in the organic phase strips more easily. Extraction rate of P204 0.1 mol/L+0.1 mol/L TRPO can achieve 99% above by level 2th extracting to indium sulfate solution containing Indium 1.15 g/L. When the loaded organic phase was 0.1 mol/LP204+0.1 mol/LTOPO, using 2 mol/L sulfuric acid, stripping rate of indium is 93.58%. Indium in mixed organic phase extraction is easlier striping than single P204 organic phase. Sulfuric acid and can be used as striping agent, which can avoid that Adverse effects due to using high concentration of hydrochloric acid as striping agent to the traditional single P204 loading indium organic phase.