The extraction experiments of chromium（W） from aqueous waste solution by predispersed solvent extraction （PDSE） process with extractant （HEHPEHE） and its mixture, including acidic extractant （D2EHPA）, alkaline...The extraction experiments of chromium（W） from aqueous waste solution by predispersed solvent extraction （PDSE） process with extractant （HEHPEHE） and its mixture, including acidic extractant （D2EHPA）, alkaline extractant （TOA） and neutral extractant （TBP） were carried out respectively. It is found that the extractant HEHPEHE exhibited high extraction selectivity to chromium（III） from aqueous waste solution. The colloidal liquid aphrons （CLAs） were successfully generated using kerosene as a solvent, HEHPEHE as an extractant, sodium dodecyl benzene sulphate （SDBS） as a surfactant in aqueous phase and polyoxyethylene sorbitol anhydride monolaurate （Tween-20） in oil phase. To study the extraction efficiency and advantages of the PDSE process in the removal of chromium（III）, the effects of major factors, such as initial chromium（III） concentration, volume of colloidal gas aphrons （CGAs）, HEHPEHE volume fraction, phase ratio （solvent phase to water phase）, mass fraction of dodecyl trimethylammonium bromide （HTAB）, mass fraction of SDBS, mass fraction of Tween-20 and initial pH of aqueous waste solution were also investigated and the appropriate process conditions were obtained. Under the appropriate conditions, the extraction efficiency of chromium（III） above 99.9 % can be achieved and the treated aqueous waste solution can be discharged directly without polluting the environment.展开更多
Nickel, cobalt and copper were separated by solvent extraction with P204. The experimental results show that [Co(NH 3) 6] 3+ is an inert complex in extraction kinetics, therefore cobalt can be separated from nickel an...Nickel, cobalt and copper were separated by solvent extraction with P204. The experimental results show that [Co(NH 3) 6] 3+ is an inert complex in extraction kinetics, therefore cobalt can be separated from nickel and copper by non equilibrium solvent extraction. Under the conditions of temperature 25?℃, contact time of two phases 10?min, phase ratio 1∶1, aqueous pH 10.10 and concentration of P204 20%, [Co(NH 3) 6] 3+ is hardly extracted by P204, while the percentage extractions of nickel and copper are 79.3% and 93.9% respectively. Nickel and copper are separated by equilibrium solvent extraction with P204. Under the conditions of temperature 25?℃, contact time of two phases 1?min, phase ratio 1∶1, equilibrium pH 4.01 and concentration of P204 20%, the separation factor of copper and nickel is 216.展开更多
Using experimental data from a number of pulsed disc and doughnut solvent extraction columns, a unified correla- tion for the prediction of dispersed phase holdup that considers the effects of mass transfer is present...Using experimental data from a number of pulsed disc and doughnut solvent extraction columns, a unified correla- tion for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented. Pulsed disc and doughnut solvent extraction columns （PDDC） have been used for a range of important applications such as ura- nium extraction and nuclear fuel recycling. Although the dispersed phase holdup in a PDDC has been presented by some researchers, there is still the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction. In this study, dis- persed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland lind. Eng. Chem. Res.,27 （1988）,131-138] which did not consider the effect of col- umn geometry. In order to incorporate the characteristic length of the PDDC （i.e. the plate spacing）, the unified cor- relation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind. Eng. Chem. Res.,34 （1995） 3925-3940] was refitted to the PDDC data. New constants have been presented for each hold- up correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of onerating conditions and nhwical nronerties and consider the direction of mass transfer.展开更多
The solvent extraction technology, was applied to recover Cu^2＋ and Ni^2＋ from plating wastewater.Lix984N was chosen as the extractant due to-its gooff extraction performance. The influence parame-ters were examlned...The solvent extraction technology, was applied to recover Cu^2＋ and Ni^2＋ from plating wastewater.Lix984N was chosen as the extractant due to-its gooff extraction performance. The influence parame-ters were examlned. The results show that the separation of Cu^2＋ and Ni＂ from sulphate medium can be realized by adjusting pH value with the help of Lix984N. For extracting Cu^2＋ and Ni^2＋, the optimal pH values are 4 and 10.5, and the maximal extraction percentages are 92.9% and 93.0%, respectively .With recovered Cu^2＋ and Ni^2＋ stripped in 170g.L^ -1 and 200 g.L^-1 H2SO4 medium, the stripping percentages of Cu^2＋ and Ni^2＋ are 92.9% and 93.0%, respectively. This method is simple and can be used to recover Cu^2＋ and Ni^2＋ from plating wastewater. And a flow sheet for separation of Cu^2＋ and Ni^2＋ is presented.展开更多
Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various det...Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various determination methods. The effects of leaching time,leaching temperature,leaching agent concentration,leaching L/S ratio,granularity of material,additive consumption were investigated based on the mineralogy.The results show that under the conditions of leaching time of 3-4 h, temperature of 150℃,sulfuric acid consumption of 25%?30%,ratio of liquid to solid of 1.2:1,the granularity less than 0.074 mm, additive consumption of 3%-5%,and oxygen pressure of 1.2 MPa,and the vanadium leaching rate can be more than 92%by the method of two-step pressurized acid leaching.The powdery V2O5 product with 99.52%in V2O5 content is obtained by the flowsheet of acid recovery,removing iron by reduction process,solvent extraction,precipitating vanadium with ammonium water,and pyrolysis from the stone-coal oxygen pressure acid-leaching solution.The total recovery efficiency of vanadium is above 85%,which is more than 20%higher than that obtained in the conventional process.Furthermore,the new process does not cause air pollution since no HCl or Cl2 is released by calcination of the raw material.展开更多
An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LI...An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LIX 984N is highly selective and very efficient in the extraction of Cu（Ⅱ）, and the analysis of variance indicates that the sequence of parameters according to their influence on the separation efficiency is phase ratio 〉 LIX 984N concentration 〉 pH value 〉 extraction time. The optimal condition for copper extraction is obtained as 25% of LIX 984N concentration, 7 rain of extraction time, 3：2 of phase ratio O/A, and pH = 1.7. The separation of Zn（Ⅱ） and Cd（Ⅱ） was performed after the copper extraction from the raffinate. Comparative analysis of the separation with di-2-ethylhexyl phosphoric acid （D2EHPA）, D2EHPA-tributyl- phosophate （TBP） synergistic extracting system, and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester （HEHEHP） was made at pH = 2.0. It is demonstrated that the extraction efficiency with D2EHPA is improved after being saponified by sodium hydroxide, and D2EHPA-TBP synergistic extracting, as well as HEHEHP, has a superior selectivity to Zn（Ⅱ） over Cd（Ⅱ）.展开更多
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....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.展开更多
The behaviour of vanadium（V） extracted from sulfuric acid solution was investigated using Cyanex 923 as an extractant. The effects of the concentration of Cyanex 923 and the pH of the solution were studied. The extr...The behaviour of vanadium（V） extracted from sulfuric acid solution was investigated using Cyanex 923 as an extractant. The effects of the concentration of Cyanex 923 and the pH of the solution were studied. The extraction of vanadium（V） increases with the increase of Cyanex 923 concentration and shaking time. Cyanex 923 can extract vanadium（V） from sulfuric acid solution at low pH conditions, and the best pH conditions for extraction of vanadium（V） are at pH 1.0-2.0. The species extracted into the organic phase is VO2HSO4 with one molecule of Cyanex 923. Equilibrium studies were used to assess the extraction efficiency of vanadium（V） recovery from the sulfuric acid solution.展开更多
The application of soxhlet, ultrasonic and accelerated solvent extractiontechniques to the analysis of six organochlorine pesticides (α-HCH, β-HCH, γ-HCH, o, p'-DDT,p,p'-DDT and p,p'-DDE) in Taihu Lake ...The application of soxhlet, ultrasonic and accelerated solvent extractiontechniques to the analysis of six organochlorine pesticides (α-HCH, β-HCH, γ-HCH, o, p'-DDT,p,p'-DDT and p,p'-DDE) in Taihu Lake sediment samples is described. It was found that the limits ofquantification ranged from 0.002 μg g^(-1) to 0.004 μg g^(-1), and the recoveries oforganochlorine pesticides with the three extraction techniques were acceptable ( 】80.7%). With amass selective detector, better results were obtained by accelerated solvent extraction usinghexane-acetone (1:1) as compared with soxhlet and ultrasonic extraction. It was shown that theaccelerated solvent extraction was the optimum technique for the analysis of organochlorinepesticides in sediments. The general features of the three extraction techniques are also presented.展开更多
A direct solvent extraction（DSX） process for purifying nickel and cobalt from the nitric acid leach solution of nickel laterite ores was conceived and experimentally probed. The proposed process consists of two solv...A direct solvent extraction（DSX） process for purifying nickel and cobalt from the nitric acid leach solution of nickel laterite ores was conceived and experimentally probed. The proposed process consists of two solvent extraction（SX） steps but with only one extractant - bis（2,4,4-trimethylpentyl）phosphinic acid（Cyanex？ 272） - used in both steps. The first extraction step involved the removal of aluminum and zinc, whereas the second extraction step involved the separation of cobalt along with manganese from nickel. The experimental results showed essentially quantitative removal of aluminum（〉97%） and zinc（〉99%） in a single extraction stage using 20vol% Cyanex 272 at pH 2.1. Some cobalt（32%） and manganese（55%） were co-extracted but were easily scrubbed out completely from the loaded organic phase using dilute sulfuric acid at pH ≤ 1.38. Cobalt and manganese in the first extraction raffinate were extracted completely in four extraction stages at staggered pH values of 4.0, 4.4, 4.5, and 4.0 in the first, second, third, and fourth stages, respectively, using also 20vol% Cyanex 272. A small amount of nickel（up to 6.6%） was co-extracted but was easily scrubbed out completely with dilute sulfuric acid at pH 2.0. A flow diagram showing the input and output conditions and the metals separated under the deduced optimum conditions is presented.展开更多
Replacement of volatile organic compounds （VOCs） by greener or more environmentally sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns as well as economic...Replacement of volatile organic compounds （VOCs） by greener or more environmentally sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns as well as economic pressures associated with VOCs. Solvents that are derived from biomass, namely bio-derived solvents, are a type of green solvent that have attracted intensive investigations in recent years because of their advantages over con- ventional VOCs, such as low toxicity, biodegradability and renewability. This review aims to summarize the use of bio-derived solvents in solvent extraction applications, with special emphasis given to utilization of biodiesels and terpenes. Compared with the conventional VOCs, the overall performance of these bio-derived solvents is comparable in terms of extraction yields and selectivity for natural product extraction and no difference was found for metal extraction. To date most researchers have focused on laboratory scale thermodynamics studies. Future work is required to develop and test new bio-derived solvents and understand the kinetic performance as well as solvent extraction nilnt nlant studies.展开更多
Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) an...Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexly 4-pyridinecarboxylate ester (4PC) for the extraction of cobalt from acidic single metal sulfate solution was carried out to suggest how the physicochemical properties and the morphology of the reverse micelles in the loaded organic phase affect the phase separation. The results show that effective parameters affecting the phase separation are the viscosity and the excess water uptake of the loaded organic phase. It is obvious that the specific settling rate (SSR) decreases with the apparent increase of these two parameters. The measurement of small angle X-ray scattering (SAXS) proves that the morphology of the reversed micelles in the loaded organic phase changes evidently with the change of the specific settling rate (SSR).展开更多
The use of the guanidine extractant LIX 7950 extracting copper and cyanide from alkaline cyanide solution was investigated.The extraction of copper and cyanide under different initial copper and extractant concentrati...The use of the guanidine extractant LIX 7950 extracting copper and cyanide from alkaline cyanide solution was investigated.The extraction of copper and cyanide under different initial copper and extractant concentrations was examined and the stoichiometric extraction constant of Cu(CN)32- with LIX 7950 was calculated.Both the distribution coefficient and the stoichiometric extraction constant of Cu(CN)3 2-with LIX 7950 decrease when the temperature is varied from 25℃to 45℃, indicating the extraction process is exothermic.The calculated enthalpy change of the reaction(-HΘ)is about-190 kJ/mol.The copper extraction isotherms under different molar ratios of cyanide to copper are established.The preferential extraction of Cu(CN)32- over Cu(CN)4 3-and CN -has been confirmed and a high cyanide-to-copper molar ratio tends to suppress copper loading. The loaded copper and cyanide can be stripped efficiently by the moderately strong NaOH solutions(0.5-1.0 mol/L)and the presence of NaCN in the stripping solution facilitates copper stripping.展开更多
The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study...The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study results showed that the solid particle is one of the most important contributors for the formation of the third phase crud. During solvent extraction, if the pH value was greater than 2.30, the number of solid particles in the mother solution increased, in which case the possibility of forming the third phase crud could also increase, and the interface tension value might grow in pace with the quantity of the third phase crud.展开更多
A plumbomicrolite concentrate(PMC)was leached with the mixture of HF and H2SO4,HF and HNO3 acids,respectively.Optimal conditions ensuring high recovery of tantalum and niobium(up to 99%)into solution,and radionuclides...A plumbomicrolite concentrate(PMC)was leached with the mixture of HF and H2SO4,HF and HNO3 acids,respectively.Optimal conditions ensuring high recovery of tantalum and niobium(up to 99%)into solution,and radionuclides into insoluble residue were determined.Fluoride-sulfuric acid and fluoride-nitric acid schemes were proposed for PMC leaching by an extractive separation of tantalum form niobium,lead and impurities,and production of high-purity tantalum compounds.Octanol-1 was used as an extractant.Optimal conditions for production of high-purity tantalum strip solutions were defined for all stages(extraction-scrubbing-stripping).Produced tantalum compounds,such as tantalum pentoxide and potassium heptafluotanthalate,comply with the norms for high-purity substances in terms of impurities content.Final choice of the PMC processing scheme is determined by its profitability.展开更多
The extraction of the trivalent middle rare earths from chloride media by kerosene solutions of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as an extractant was studied. The separation factors between the elem...The extraction of the trivalent middle rare earths from chloride media by kerosene solutions of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as an extractant was studied. The separation factors between the elements using solution simulating wastes from NiMH spent batteries have been evaluated: the order of the extractive ability of extractant can be confirmed in Tb>Gd>Eu>Sm.展开更多
Functionalized ionic liquids(FILs)as extractants were employed for the separation of tungsten and molybdenum from a sulfate solution for the first time.The effects of initial pH,extractant concentration,metal concentr...Functionalized ionic liquids(FILs)as extractants were employed for the separation of tungsten and molybdenum from a sulfate solution for the first time.The effects of initial pH,extractant concentration,metal concentrations in the feed were comprehensively investigated.The results showed that tricaprylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate([A336][Cyanex272])could selectively extract W over Mo at an initial pH value of 5.5;the best separation factorβ_(W/Mo) of 25.61 was obtained for a solution with low metal concentrations(WO3:2.49 g/L,Mo:1.04 g/L).The[A336][Cyanex272]system performed effectively for solutions of different W/Mo molar ratios and different metal ion concentrations in the feed.The chemical reaction between[A336][Cyanex272]and W followed the ion association mechanism,which was further proved by the Fourier-transform infrared(FTIR)spectra of loaded[A336][Cyanex272]and the free extractant.The stripping experiments indicated that 95.48%W and 100.00%Mo were stripped using a 0.20 mol/L sodium hydroxide solution.Finally,the selective extractions of W and Mo from two synthetic solutions of different high metal concentrations were obtained;the separation factorβW/Mo reached 23.24 and 17.59 for the first and second solutions,respectively.The results suggest the feasibility of[A336][Cyanex272]as an extractant for the separation of tungsten and molybdenum.展开更多
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 (equi...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.展开更多
Predispersed solvent extraction (PDSE) is a new method for separating solutes from aqueous solution by solvent extraction and one which has shown promise for extraction from extremely dilute solution very efficient an...Predispersed solvent extraction (PDSE) is a new method for separating solutes from aqueous solution by solvent extraction and one which has shown promise for extraction from extremely dilute solution very efficient and very quick. The use of colloidal liquid aphrons in predispersed solvent extraction may ameliorate the problems such as emulsion formation, reduction of interfacial mass transfer and low interfacial mass transfer areas in solvent extraction process. In present paper, colloidal liquid aphrons are successfully generated using kerosene as a solvent, tributyl phosphate(TBP) as an extractant, sodium dodecyl benzene sulphate(SDBS) as surfactant in aqueous phase and Tween-80 in oil phase. Extraction of phenol from dilute solution was studied by using colloidal liquid aphrons and colloidal gas aphrons in a semi-batch extraction column. It has been found that the PDSE process is more suitable for extraction of dilute solutions. It has also been discovered that the PDSE process has a great advantage over traditional single-stage extraction process.展开更多
In this study, an ionic liquid(IL), 1-butyl-2,3-dimmmethylimidazolium hexafluorophosphate([Bmmim][PF6]),was used in combination with a composite solvent of methyl acetate and n-heptane to enhance the oil extraction fr...In this study, an ionic liquid(IL), 1-butyl-2,3-dimmmethylimidazolium hexafluorophosphate([Bmmim][PF6]),was used in combination with a composite solvent of methyl acetate and n-heptane to enhance the oil extraction from oily sludge. The oil recovery increased by approximately 15% compared with that of solvent extraction without [Bmmim][PF6] at the optimal ratios of IL to sludge and solvents to sludge, which were at 2:5(M/M) and 4:1(V/M), respectively. The saturate, aromatic, resin and asphaltene(SARA) analysis revealed that the recovery of resins and asphaltenes was increased by 14% and 38%, respectively, in the solvent extraction with the addition of [Bmmim][PF6]. [Bmmim][PF6] maintained a good performance after its reuse four times. The addition of[Bmmim][PF6] changed the adhesion forces between oil and soil. The IL-assisted solvent extraction procedure followed the pseudo second-order kinetic model, while the unassisted solvent extraction procedure followed the pseudo first-order kinetic model. The results also demonstrated that [Bmmim][PF6] decreased the solvent consumption by approximately 60% each time. Additionally, [Bmmim][PF6] can be easily separated. The results suggested that enhancing the solvent extraction with this IL is a promising way to recover oil from oily sludge with a higher oil recovery rate and lower organic solvent consumption than those with the unassisted solvent extraction method.展开更多
基金Project (NCET-07-0577) supported by New Century Excellent Talents of Ministry of Education, China
文摘The extraction experiments of chromium（W） from aqueous waste solution by predispersed solvent extraction （PDSE） process with extractant （HEHPEHE） and its mixture, including acidic extractant （D2EHPA）, alkaline extractant （TOA） and neutral extractant （TBP） were carried out respectively. It is found that the extractant HEHPEHE exhibited high extraction selectivity to chromium（III） from aqueous waste solution. The colloidal liquid aphrons （CLAs） were successfully generated using kerosene as a solvent, HEHPEHE as an extractant, sodium dodecyl benzene sulphate （SDBS） as a surfactant in aqueous phase and polyoxyethylene sorbitol anhydride monolaurate （Tween-20） in oil phase. To study the extraction efficiency and advantages of the PDSE process in the removal of chromium（III）, the effects of major factors, such as initial chromium（III） concentration, volume of colloidal gas aphrons （CGAs）, HEHPEHE volume fraction, phase ratio （solvent phase to water phase）, mass fraction of dodecyl trimethylammonium bromide （HTAB）, mass fraction of SDBS, mass fraction of Tween-20 and initial pH of aqueous waste solution were also investigated and the appropriate process conditions were obtained. Under the appropriate conditions, the extraction efficiency of chromium（III） above 99.9 % can be achieved and the treated aqueous waste solution can be discharged directly without polluting the environment.
文摘Nickel, cobalt and copper were separated by solvent extraction with P204. The experimental results show that [Co(NH 3) 6] 3+ is an inert complex in extraction kinetics, therefore cobalt can be separated from nickel and copper by non equilibrium solvent extraction. Under the conditions of temperature 25?℃, contact time of two phases 10?min, phase ratio 1∶1, aqueous pH 10.10 and concentration of P204 20%, [Co(NH 3) 6] 3+ is hardly extracted by P204, while the percentage extractions of nickel and copper are 79.3% and 93.9% respectively. Nickel and copper are separated by equilibrium solvent extraction with P204. Under the conditions of temperature 25?℃, contact time of two phases 1?min, phase ratio 1∶1, equilibrium pH 4.01 and concentration of P204 20%, the separation factor of copper and nickel is 216.
文摘Using experimental data from a number of pulsed disc and doughnut solvent extraction columns, a unified correla- tion for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented. Pulsed disc and doughnut solvent extraction columns （PDDC） have been used for a range of important applications such as ura- nium extraction and nuclear fuel recycling. Although the dispersed phase holdup in a PDDC has been presented by some researchers, there is still the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction. In this study, dis- persed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland lind. Eng. Chem. Res.,27 （1988）,131-138] which did not consider the effect of col- umn geometry. In order to incorporate the characteristic length of the PDDC （i.e. the plate spacing）, the unified cor- relation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind. Eng. Chem. Res.,34 （1995） 3925-3940] was refitted to the PDDC data. New constants have been presented for each hold- up correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of onerating conditions and nhwical nronerties and consider the direction of mass transfer.
基金Supported by the National Key Technologies Research and Development Program of China during the 1 lth Five-Year Plan Period （2007BAB22B01） and the Young Science Foundation of Jiangxi Province Education Office （GJJ11124）.
文摘The solvent extraction technology, was applied to recover Cu^2＋ and Ni^2＋ from plating wastewater.Lix984N was chosen as the extractant due to-its gooff extraction performance. The influence parame-ters were examlned. The results show that the separation of Cu^2＋ and Ni＂ from sulphate medium can be realized by adjusting pH value with the help of Lix984N. For extracting Cu^2＋ and Ni^2＋, the optimal pH values are 4 and 10.5, and the maximal extraction percentages are 92.9% and 93.0%, respectively .With recovered Cu^2＋ and Ni^2＋ stripped in 170g.L^ -1 and 200 g.L^-1 H2SO4 medium, the stripping percentages of Cu^2＋ and Ni^2＋ are 92.9% and 93.0%, respectively. This method is simple and can be used to recover Cu^2＋ and Ni^2＋ from plating wastewater. And a flow sheet for separation of Cu^2＋ and Ni^2＋ is presented.
基金Project(2006AA06Z130)supported by the High-tech Research and Development Program of ChinaProject(50874053)supported by the National Natural Science Foundation of ChinaProject(2007GA010)supported by Science and Technology Bureau of Yunnan Province,China
文摘Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various determination methods. The effects of leaching time,leaching temperature,leaching agent concentration,leaching L/S ratio,granularity of material,additive consumption were investigated based on the mineralogy.The results show that under the conditions of leaching time of 3-4 h, temperature of 150℃,sulfuric acid consumption of 25%?30%,ratio of liquid to solid of 1.2:1,the granularity less than 0.074 mm, additive consumption of 3%-5%,and oxygen pressure of 1.2 MPa,and the vanadium leaching rate can be more than 92%by the method of two-step pressurized acid leaching.The powdery V2O5 product with 99.52%in V2O5 content is obtained by the flowsheet of acid recovery,removing iron by reduction process,solvent extraction,precipitating vanadium with ammonium water,and pyrolysis from the stone-coal oxygen pressure acid-leaching solution.The total recovery efficiency of vanadium is above 85%,which is more than 20%higher than that obtained in the conventional process.Furthermore,the new process does not cause air pollution since no HCl or Cl2 is released by calcination of the raw material.
文摘An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LIX 984N is highly selective and very efficient in the extraction of Cu（Ⅱ）, and the analysis of variance indicates that the sequence of parameters according to their influence on the separation efficiency is phase ratio 〉 LIX 984N concentration 〉 pH value 〉 extraction time. The optimal condition for copper extraction is obtained as 25% of LIX 984N concentration, 7 rain of extraction time, 3：2 of phase ratio O/A, and pH = 1.7. The separation of Zn（Ⅱ） and Cd（Ⅱ） was performed after the copper extraction from the raffinate. Comparative analysis of the separation with di-2-ethylhexyl phosphoric acid （D2EHPA）, D2EHPA-tributyl- phosophate （TBP） synergistic extracting system, and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester （HEHEHP） was made at pH = 2.0. It is demonstrated that the extraction efficiency with D2EHPA is improved after being saponified by sodium hydroxide, and D2EHPA-TBP synergistic extracting, as well as HEHEHP, has a superior selectivity to Zn（Ⅱ） over Cd（Ⅱ）.
文摘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.
基金supported by the Science Foundation of Central South University (No. 76112037) the Postdoctoral Science Foundation of Central South University
文摘The behaviour of vanadium（V） extracted from sulfuric acid solution was investigated using Cyanex 923 as an extractant. The effects of the concentration of Cyanex 923 and the pH of the solution were studied. The extraction of vanadium（V） increases with the increase of Cyanex 923 concentration and shaking time. Cyanex 923 can extract vanadium（V） from sulfuric acid solution at low pH conditions, and the best pH conditions for extraction of vanadium（V） are at pH 1.0-2.0. The species extracted into the organic phase is VO2HSO4 with one molecule of Cyanex 923. Equilibrium studies were used to assess the extraction efficiency of vanadium（V） recovery from the sulfuric acid solution.
文摘The application of soxhlet, ultrasonic and accelerated solvent extractiontechniques to the analysis of six organochlorine pesticides (α-HCH, β-HCH, γ-HCH, o, p'-DDT,p,p'-DDT and p,p'-DDE) in Taihu Lake sediment samples is described. It was found that the limits ofquantification ranged from 0.002 μg g^(-1) to 0.004 μg g^(-1), and the recoveries oforganochlorine pesticides with the three extraction techniques were acceptable ( 】80.7%). With amass selective detector, better results were obtained by accelerated solvent extraction usinghexane-acetone (1:1) as compared with soxhlet and ultrasonic extraction. It was shown that theaccelerated solvent extraction was the optimum technique for the analysis of organochlorinepesticides in sediments. The general features of the three extraction techniques are also presented.
基金the Indonesia Endowment Fund for Education(LPDP)for the scholarship of Z.T.Ichlas,Shell Chemicals for supplying ShellS ol 2046 and Cytec Australia for supplying Cyanex 272
文摘A direct solvent extraction（DSX） process for purifying nickel and cobalt from the nitric acid leach solution of nickel laterite ores was conceived and experimentally probed. The proposed process consists of two solvent extraction（SX） steps but with only one extractant - bis（2,4,4-trimethylpentyl）phosphinic acid（Cyanex？ 272） - used in both steps. The first extraction step involved the removal of aluminum and zinc, whereas the second extraction step involved the separation of cobalt along with manganese from nickel. The experimental results showed essentially quantitative removal of aluminum（〉97%） and zinc（〉99%） in a single extraction stage using 20vol% Cyanex 272 at pH 2.1. Some cobalt（32%） and manganese（55%） were co-extracted but were easily scrubbed out completely from the loaded organic phase using dilute sulfuric acid at pH ≤ 1.38. Cobalt and manganese in the first extraction raffinate were extracted completely in four extraction stages at staggered pH values of 4.0, 4.4, 4.5, and 4.0 in the first, second, third, and fourth stages, respectively, using also 20vol% Cyanex 272. A small amount of nickel（up to 6.6%） was co-extracted but was easily scrubbed out completely with dilute sulfuric acid at pH 2.0. A flow diagram showing the input and output conditions and the metals separated under the deduced optimum conditions is presented.
基金Support from the Australian Research Council (project ID:LP140100650)
文摘Replacement of volatile organic compounds （VOCs） by greener or more environmentally sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns as well as economic pressures associated with VOCs. Solvents that are derived from biomass, namely bio-derived solvents, are a type of green solvent that have attracted intensive investigations in recent years because of their advantages over con- ventional VOCs, such as low toxicity, biodegradability and renewability. This review aims to summarize the use of bio-derived solvents in solvent extraction applications, with special emphasis given to utilization of biodiesels and terpenes. Compared with the conventional VOCs, the overall performance of these bio-derived solvents is comparable in terms of extraction yields and selectivity for natural product extraction and no difference was found for metal extraction. To date most researchers have focused on laboratory scale thermodynamics studies. Future work is required to develop and test new bio-derived solvents and understand the kinetic performance as well as solvent extraction nilnt nlant studies.
基金Project(2014CB643401) supported by the National Basic Research Program of ChinaProject(51674294) supported by the National Natural Science Foundation of ChinaProject(2016TP1007) supported by the Hunan Provincial Science and Technology Plan,China
文摘Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexly 4-pyridinecarboxylate ester (4PC) for the extraction of cobalt from acidic single metal sulfate solution was carried out to suggest how the physicochemical properties and the morphology of the reverse micelles in the loaded organic phase affect the phase separation. The results show that effective parameters affecting the phase separation are the viscosity and the excess water uptake of the loaded organic phase. It is obvious that the specific settling rate (SSR) decreases with the apparent increase of these two parameters. The measurement of small angle X-ray scattering (SAXS) proves that the morphology of the reversed micelles in the loaded organic phase changes evidently with the change of the specific settling rate (SSR).
文摘The use of the guanidine extractant LIX 7950 extracting copper and cyanide from alkaline cyanide solution was investigated.The extraction of copper and cyanide under different initial copper and extractant concentrations was examined and the stoichiometric extraction constant of Cu(CN)32- with LIX 7950 was calculated.Both the distribution coefficient and the stoichiometric extraction constant of Cu(CN)3 2-with LIX 7950 decrease when the temperature is varied from 25℃to 45℃, indicating the extraction process is exothermic.The calculated enthalpy change of the reaction(-HΘ)is about-190 kJ/mol.The copper extraction isotherms under different molar ratios of cyanide to copper are established.The preferential extraction of Cu(CN)32- over Cu(CN)4 3-and CN -has been confirmed and a high cyanide-to-copper molar ratio tends to suppress copper loading. The loaded copper and cyanide can be stripped efficiently by the moderately strong NaOH solutions(0.5-1.0 mol/L)and the presence of NaCN in the stripping solution facilitates copper stripping.
基金This study is financially supported by the "973" National Basic Research of China (No. 2004CB619206).
文摘The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study results showed that the solid particle is one of the most important contributors for the formation of the third phase crud. During solvent extraction, if the pH value was greater than 2.30, the number of solid particles in the mother solution increased, in which case the possibility of forming the third phase crud could also increase, and the interface tension value might grow in pace with the quantity of the third phase crud.
基金Project supported by the Federal Research Centre of Kola Science Centre of the Russian Academy of Sciences,Russian。
文摘A plumbomicrolite concentrate(PMC)was leached with the mixture of HF and H2SO4,HF and HNO3 acids,respectively.Optimal conditions ensuring high recovery of tantalum and niobium(up to 99%)into solution,and radionuclides into insoluble residue were determined.Fluoride-sulfuric acid and fluoride-nitric acid schemes were proposed for PMC leaching by an extractive separation of tantalum form niobium,lead and impurities,and production of high-purity tantalum compounds.Octanol-1 was used as an extractant.Optimal conditions for production of high-purity tantalum strip solutions were defined for all stages(extraction-scrubbing-stripping).Produced tantalum compounds,such as tantalum pentoxide and potassium heptafluotanthalate,comply with the norms for high-purity substances in terms of impurities content.Final choice of the PMC processing scheme is determined by its profitability.
文摘The extraction of the trivalent middle rare earths from chloride media by kerosene solutions of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as an extractant was studied. The separation factors between the elements using solution simulating wastes from NiMH spent batteries have been evaluated: the order of the extractive ability of extractant can be confirmed in Tb>Gd>Eu>Sm.
基金financially supported by the National Natural Science Foundation of China(No.51504225).
文摘Functionalized ionic liquids(FILs)as extractants were employed for the separation of tungsten and molybdenum from a sulfate solution for the first time.The effects of initial pH,extractant concentration,metal concentrations in the feed were comprehensively investigated.The results showed that tricaprylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate([A336][Cyanex272])could selectively extract W over Mo at an initial pH value of 5.5;the best separation factorβ_(W/Mo) of 25.61 was obtained for a solution with low metal concentrations(WO3:2.49 g/L,Mo:1.04 g/L).The[A336][Cyanex272]system performed effectively for solutions of different W/Mo molar ratios and different metal ion concentrations in the feed.The chemical reaction between[A336][Cyanex272]and W followed the ion association mechanism,which was further proved by the Fourier-transform infrared(FTIR)spectra of loaded[A336][Cyanex272]and the free extractant.The stripping experiments indicated that 95.48%W and 100.00%Mo were stripped using a 0.20 mol/L sodium hydroxide solution.Finally,the selective extractions of W and Mo from two synthetic solutions of different high metal concentrations were obtained;the separation factorβW/Mo reached 23.24 and 17.59 for the first and second solutions,respectively.The results suggest the feasibility of[A336][Cyanex272]as an extractant for the separation of tungsten and molybdenum.
基金Project(50321402) supported by the National Natural Science Foundation of China
文摘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.
基金Supported by the National Natural Science Foundation of China(No.29676021 and No.29836130)
文摘Predispersed solvent extraction (PDSE) is a new method for separating solutes from aqueous solution by solvent extraction and one which has shown promise for extraction from extremely dilute solution very efficient and very quick. The use of colloidal liquid aphrons in predispersed solvent extraction may ameliorate the problems such as emulsion formation, reduction of interfacial mass transfer and low interfacial mass transfer areas in solvent extraction process. In present paper, colloidal liquid aphrons are successfully generated using kerosene as a solvent, tributyl phosphate(TBP) as an extractant, sodium dodecyl benzene sulphate(SDBS) as surfactant in aqueous phase and Tween-80 in oil phase. Extraction of phenol from dilute solution was studied by using colloidal liquid aphrons and colloidal gas aphrons in a semi-batch extraction column. It has been found that the PDSE process is more suitable for extraction of dilute solutions. It has also been discovered that the PDSE process has a great advantage over traditional single-stage extraction process.
基金financial support from the National Natural Science Foundation of China(Nos.41807133 and 41977142)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.18K05ESPCT)the Fundamental Research Funds for the Central Universities(PT1915)。
文摘In this study, an ionic liquid(IL), 1-butyl-2,3-dimmmethylimidazolium hexafluorophosphate([Bmmim][PF6]),was used in combination with a composite solvent of methyl acetate and n-heptane to enhance the oil extraction from oily sludge. The oil recovery increased by approximately 15% compared with that of solvent extraction without [Bmmim][PF6] at the optimal ratios of IL to sludge and solvents to sludge, which were at 2:5(M/M) and 4:1(V/M), respectively. The saturate, aromatic, resin and asphaltene(SARA) analysis revealed that the recovery of resins and asphaltenes was increased by 14% and 38%, respectively, in the solvent extraction with the addition of [Bmmim][PF6]. [Bmmim][PF6] maintained a good performance after its reuse four times. The addition of[Bmmim][PF6] changed the adhesion forces between oil and soil. The IL-assisted solvent extraction procedure followed the pseudo second-order kinetic model, while the unassisted solvent extraction procedure followed the pseudo first-order kinetic model. The results also demonstrated that [Bmmim][PF6] decreased the solvent consumption by approximately 60% each time. Additionally, [Bmmim][PF6] can be easily separated. The results suggested that enhancing the solvent extraction with this IL is a promising way to recover oil from oily sludge with a higher oil recovery rate and lower organic solvent consumption than those with the unassisted solvent extraction method.
