粘胶纤维生产废水中萃取锌试验

以二-2乙基已基磷酸和磷酸三丁酯作为萃取剂,用三氯乙烯、氟里昂、煤油作为冲淡剂,有机相和水相之比1∶1,经过多段相接触可以大幅度提高废水中锌萃取率。用双硫棕比色法测定萃取后的溶液里锌含量。

铜锌混合氧化矿回收锌生产实践

铜锌混合氧化矿属于复杂含锌矿物,采用浮选法对氧化矿中的铜矿物和锌矿物进行分离的效果比较差。某冶炼企业将铜锌混合氧化矿采用浸出-萃取-电积提取金属铜和金属锌,该工艺中除锌萃取技术外,其他技术均属于常规工艺。锌萃取工艺采取P204为萃取剂,260~#溶剂油为稀释剂,富锌液经除油工序后再经压滤,然后送锌电积工序。针对生产实践中的问题通过采取提高锌萃取原液的锌浓度、优化萃取工艺、加强设备防腐等措施均已得到解决,锌锭实际产能超过了设计产能,达到1.3~1.4万t/a。该项目的成功运行实现了从铜锌混合氧化矿物中综合提取金属铜和锌,为后续新建项目的设计及生产提供了经验。

Synergistic extraction of zinc from ammoniacal solutions using β-diketone mixed with CYANEX923 or LIX84I

The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone （HA） and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentration, anion species and temperature on zinc extraction were examined. The synergistic mechanism was discussed with regard to the structure of extractant and the extracted zinc complexes. It is found that the increase of total ammonia concentration and pH inhibits zinc extraction for all extraction systems due to the formation of zinc ammine complexes in aqueous phase. This effect of HA with CYANEX923 is evidently smaller than that of HA with LIX84I or HA alone system. Effect of anion species on the zinc extraction by HA with CYANEX923 can be neglected, but this effect of HA alone and the mixture of HA with LIX84I decreases in the order of （NH4）2SO4 〉 NH4NO3 〉 NH4Cl.

Recovery of nickel,cobalt,copper and zinc in sulphate and chloride solutions using synergistic solvent extraction

A number of synergistic solvent extraction （SSX） systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia. These in- clude （1） Versatic 10/CLXS0 system for the separation of Ni from Ca in sulphate solutions, （2） Versatic 10/4PC system for the separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, （3） Cyanex 471X/HRJ-4277 system for the separation of Zn from Cd in sulphate solutions, （4） Versatic 10/LIX63 system for the separation of Co from Mn/Mg/Ca in sulphate solutions, （5） Versatic 10/LIX63/TBP system for separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, （6） Versatic 10/LIX63 system for the separation of cobalt from nickel in sulphate solutions by difference in kinetics, （7） Cyanex 272/LIX84 system for the separation of Cu/Fe/Zn from Ni/Co in sulphate solutions, （8） Versatic 10/LIX63fFBP system to recover Cu/Ni from strong chloride solutions, and [9） Versatic 10/LIX63 system to separate Cu from Fe in strong chloride solutions. The synergistic effect on metal separation and efficiency is presented and possible industrial applications are demonstrated. The chemical stability of selected SSX systems is also reported.

Solvent extraction of zinc from zinc sulfate solution

The extraction of zinc from zinc sulfate solution was investigated, using 20% saponified D2EHPA as an extractam and 260^# sulfonate kerosene as a diluent. The solution was stirred for 8 min at phase ratio （Vσ/Va） of 1.0：1.0, initial pH of 2.0 and stirring speed of 200 r/min. The results show that 75% zinc can be extracted from the zinc sulfate solution when the concentration of zinc is 18.7 g/L after being settled for 10 min. 88.60% zinc can be stripped by 196 g/L sulfuric acid, and zinc ion can be separated from ferric ion.

Solvent extraction of copper and zinc from bioleaching solutions with LIX984 and D2EHPA

The solvent extraction of copper and zinc from the bioleaching solutions of low-grade sulfide ores with LIX984 and D2EHPA was investigated. The influences of extractant content, aqueous pH value, phase ratio and (equilibration) time on metals extraction were studied. The results show that LIX984 has a higher selectivity for copper than for iron, zinc and other metals, and has the copper extraction rate above 97%, while the zinc and iron extraction rate is less than 1.6% respectively. Zinc extraction is carried out following the copper extraction from the raffinate. The zinc extraction with di(2-ethylhexyl) phosphoric acid(D2EHPA) is low due to its poor cation exchange. A sodium salt of D2EHPA is used and the zinc extraction rate is enhanced to above 98%. Though iron (Ⅲ) is strongly extracted before the extraction of zinc by D2EHPA, it is difficult to strip iron from the organic phase by sulfuric acid. The zinc stripping rate is above 99% with 100g/L sulfuric acid, while that of iron is 0.16%. Hence, the separation of zinc from iron can be achieved by the selective stripping.

Extractability and Mobility of Copper and Zinc Accumulated in Sandy Soils

Extractability and mobility of Cu and Zn and their relationships with 1) accumulation of Cu and Zn and 2) soil pH were studied in three sandy soils (Wabasso, Ankona, and Winder) from commercial citrus groves in Florida, USA. The soils, with a broad range of Cu and Zn concentrations, were fractionated by a modified procedure of Amacher, while Cu and Zn mobility were evaluated using column leaching. The extractability of Cu and Zn increased with decreasing soil pH. Also with increasing total soil Cu and Zn for extractable Cu in the Wabasso sand a threshold level, where the metal extraction rate increased, was noted at 100 mg kg-1, whereas for extractable Zn in the Wabasso sand the threshold level was found at 60 mg kg-1 and in the Ankona sand at 120 mg kg-1. These results suggested that the release potential of Cu and Zn was greater in the Wabasso sand than in the Ankona sand. The column leaching experiment showed that at total soil Cu or Zn concentrations < 100 mg kg-1 all leachates had low Cu and Zn concentrations. However at total concentrations > 200 mg kg-1 for Cu and > 150 mg kg-1 for Zn with decreasing soil pH, the concentrations of both Cu and Zn in the leachates increased exponentially. Also in these sandy soils soluble Cu and Zn mainly originated from the exchangeable fractions, and pH was a key factor controlling Cu and Zn extractability and mobility.

Selective extraction of In(Ⅲ),Ga(Ⅲ) and Zn(Ⅱ) using a novel extractant with phenylphosphinic acid

A new extractant, [N,N-di（2-ethylhexyl）aminolmethylphenylphosphinic acid （DEAPP）, was synthesized to de- velop the mutual separation techniques of In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ）. The extraction selectivity for In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ） with DEAPP was higher than that of the commercial phosphorus acid extractants such as D2EHPA and PC-88A. The extraction selectivity for metal ions in 1 mob L 1 aqueous ammonium nitrate solution with DEAPP was in the following order： In（Ⅲ） 〉 Ga（Ⅲ） 〉 Zn（Ⅱ）. These selective extraction behaviors indicate that the amino moiety of DEAPP plays an important role in the mutual separation of ln（Ⅲ）, Ga（Ⅲ） and Zn（ll）. The extraction equilibria of In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ） with DEAPP （ = HR） were expressed by the following reactions： In3＋ ＋ 2（HR）2 InR3（HR） ＋ 3H＋, Ga3＋ ＋ 1.5（HR）2 ＋ N- = GaR2（HR）（NO3） ＋ 2H＋, and Zn2＋ 4- 2（HR）2 ZnR2 （HR） 2 determined 4- 2H＋. The extraction equilibrium constants of In（Ⅲ）, Ga（Ⅲ） and Zn（Ⅱ） with DEAPP were to be Kex, M = 1.7 × 104 [dm3.mol 1], 4.17 [（dm3.mol-1）s], and 1.55 × 10 2 [-], respectively.

Effects of Surfactant on Zinc Recovery by Solvent Extraction during Leaching in HCl-FeCl_3 Solution

The effects of surfactant on the solvent extraction in leachingsphalerite were investigated. It is found that sodium dodecylsulfonate is the effective surfactant in improving the zinc recoveryfrom sphalerite in the aqueous FeCl_3-HCl-tetrachloroethylene system.Through the measurements of surface tension and viscosity of thesphalerite Slurry modified with different surfactants, it isconcluded that sodium dodecyl sulfonate in the concentration rang Of0.05 to 0.2 g·L^-1 can improve the viscosity of sphalerite slurry inthe water, decrease the surface tension of Leaching solution, preventthe aggregation of ore particles, and give very high zinc extraction.

Extraction kinetics of zinc by new extractant in ammoniacal system

The controlling step and the extraction reaction rate equation of zinc extraction from Zn（II）-NH3 solution by using a newly synthesized organic compound, 2-acetyl-3-oxo-dithiobutyric acid-myristyl ester as the zinc extractant, were clarified. The effects of agitation speed, specific interfacial area, temperature, extractant concentration and Zn ion concentration on the extraction rate are studied in constant interfacial area cell. The results show that the extraction rate depends on interfacial chemical reaction and diffusion by using this new extraetant to extract zinc, and the apparent activation energy of this extraction reaction is measured as 28.2 kJ/mol, which demonstrates that the extraction reaction is controlled by the mixed-controlled reaction rate. The apparent reaction orders a and b are measured as 1 and 0.38, and the constant k0 is 138.70. So, when extraction conditions are controlled as [HR]=20%-50%, T=0-30℃, N=120-177 r/min and S=72.6-127.5 m-1, the solvent extraction reaction rate can be depicted as v/（mol . m-2 . s-1 ） = 138.7. exp（ - 28 206/8.314T ）. [Zn 2＋ ]r ·[HR ]o0.38.

Oxygen pressure acid leaching of Gacun complex Cu concentrates

The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary copper mineral of the concentrates.Most of silver also occurs in the mineral.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Pilot scale test was carried out under the parameters,and the leaching rates of copper and zinc are as high as 97.10% and 89.83% while lead and silver are transformed into sulfate and sulfide respectively and stay in leaching residue.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by chloride leaching and thiourea leaching.The extraction rate of copper achieves 96%,and the leaching rates of lead and silver reach 90% and 95%,respectively.

Extraction and Separation of Cadmium and Zinc with a Mixture of Di-(2-Ethylhexyl)-Dithiophosphoric Acid and Trioctyl Amine

The extraction of cadmium and zinc with di-(2-ethylhexyl)-dithiophosphoric acid(D2EHDTPA)-toluene and D2EHDTPA-trioctyl amine(TOA)-toluene has been investigated. Infrared spectrum analysis, the nuclear magnetic resonance spectrum(NMR) analysis and conductivity measurements confirm that the probable structures of the extracted complexes are CdA2 and ZnA2. Cadmium can be extracted by D2EHDTPA very easily. Almost all the cadmium can be extracted, but stripping of cadmium from the organic phase is very difficult. When a mixture of D2EHDTPA and TOA is used, selective extraction of cadmium from zinc sulfate solution can be achieved. Cadmium can be easily stripped from the organic phase.