| In this thesis, it is based on study of zinc-ammonia waste fluid which is generated during production of a metallurgical plant in Hangzhou. Solvent extraction is adopted to research reclaiming zinc from ammonia wastewater. Meanwhile, it is analyzed that the feasibility of remaining liquid back into leaching and the extraction kinetic of zinc from the zinc-ammonia wastewater. And thereupon, there could be some reference value on the treatment of the zinc-ammonia waste fluid generated in the process of production of copper extract from brass scrap.The solvent extraction in this paper was carried out with five kinds of extractant which are Lix54-100,Lix84-Ⅰ,Lix973,P204,kelex-100, and three kinds of diluents which are kerosene, sulfonated kerosene and benzene. After comparison, Lix54-100 and kerosene were selected as the extraction system. The optimum extract condition was verified through investigation of the factors including initial pH in the feed Phase, total ammonia concentration in feed solution, zinc ion concentration, extractant concentration, O/A phase ratio, temperature, etc. which has influence on zinc extraction yield and extraction quantity of ammonia. The total ammonia concentration in feed solution, zinc ion concentration, extractant concentration, O/A phase ratio, temperature and so on, then get the suitable optimum extraction conditions.When the concentration of zinc ions is 20g/L, total ammonia concentration is 20g/L, the initial pH is 8.5 in feed solution, take Lix54-100 as extraction agent, sulfonated kerosene as diluent, the extraction rate of zinc can reaches above75.45% in a single-stage under the condition of 20% for extractant concentration,3:2 for the proportion of organic and inorganic,20minutes for extraction demixing time,900rpm for agitation speed, and 3 minutes for phase separation time.Under the condition of 20% for sulphuric acid solution concentration,2:lfor the organic phase ratio(O/A), 900rpm for stirring speed,10 mininte for shaking time, and 3 minute for phase separation time, the rate of single-stage stripping can reach about 75%.The results of extraction mechanism and the qualitative analysis of extraction kinetics showed that the logarithmic of the zinc extraction distribution ratio lgDzn have the shape of a parabolic curve against equilibrium pH, and the limiting slopes of the ascending portion of the curves can be reflected the average co-ordination of zinc by ammonia ligands in the ammonia solution, the average number of ammonia ligands complexing zinc ion with increasing pH value. Linear relations between the logarithmic of the zinc extraction distribution ratio 1gDzn and the logarithmic of the extractants concentration was established, and the slopes of curves is near 2,the ammonia ligands complexing zinc ion cannot be extracted by the Extractant, and the existing NH3 in the solution can play a competition role of zinc extraction.The stirring strength and the interface contact area have a little affect on the extraction of the zinc, but the impact is not too big, and the reaction can reach equilibrium in a very short time, the extraction of zinc in the ammonia solution controlled by the mixing-controlled areas of the diffusion-controlled and chemical control, the enthalpy△H is determined as -17.88J/mol in the process of extraction of zinc in ammoniacal solution by using the extractant of lix54-100 and the process is an exothermic process, increasing the temperature was not beneficial for the extraction process.The leaching way of the brass slag by using the leach liquor of the raffinate was studied under the following conditions:temperature is 70℃and the solid-liquid ratio is 5:1, some of the valuable metals can be leached out, and also the closed circulation can be implemented. This is not only can save the use of ammonium carbonate raw materials, but also can reach the zero discharge of the waste water, and has good economic and environmental benefits.
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