Selective extraction of zinc from sulfate leach solution of zinc ore

1　INTRODUCTIONSolventextractionwasregardedasahighlyeffi cienttechniqueofseparationandpurification .Ithasbeenwidelyappliedinmetalextractionandrecoveryduringhydrometallurgicalprocessandenvironmentalprotection[14 ] .Solventextractionhasbeencommer ciallyusedintheextractionofuranium ,rarenoblemetals ,copper ,cobaltandnickel,whichwastypical lypresentedbythetechniqueofleach solventextrac tion electrowinning .Presently ,thecopperproductionfromsolventextractionhasbeenaccountedformorethan 2 0 %oft…     

Selective recovery of cobalt,nickel and lithium from sulfate leachate of cathode scrap of Li-ion batteries using liquid-liquid extraction

This paper focuses on the extractive separation and selective recovery of cobalt, nickel and lithium from the sulfate leachate of cathode scrap generated during manufacture of lithium ion batteries (LIBs). The conditions for extraction, scrubbing and stripping of cobalt from nickel and lithium are optimized with an aqueous feed containing 25.1 g·dm^?3 cobalt, 2.54 g·dm^?3 nickel and 6.2 g·dm^?3 lithium using Na-PC-88A. 99.8% Co is extracted with 60% Na-0.56 mol·dm^?3 PC-88A in two counter-current stages at an O/A phase ratio of 3/1 and an equilibrium pH of 4.5. The “crowding effect” shown for the first time provides effective scrubbing of impurities (Ni and Li) with 2.0 g·dm^?3 CoSO₄ solution. The McCabe-Thiele diagram predicts the scrubbing of 99.9% Ni and 99.9% Li at an equilibrium pH of 4.75 and O/A of 2/1 in two stages. High purity (99.9%) cobalt sulfate along with Ni and Li from the leach liquor of cathode scrap is recovered by solvent extraction. The proposed process ensures complete recycling of the waste of the manufacturing process of LIBs.     

The separation and concentration of iron from zinc process solutions

In order for solvent-extraction technology to be acceptable in the zinc industry as an alternative to existing jarosite precipitation circuits, iron must be cleanly separated and concentrated into a feed stream suitable for downstream iron by-product recovery. In this article, the use of OPAP, a mixed extractant consisting of mono- and di-octylphenyl phosphoric acids, is described as a potentially suitable extractant to selectively extract Fe(III) from concentrated ZnSO₄(90 g/l zinc)/H₂SO₄(50 g/l) solutions, followed by stripping of Fe(III) with 4–6 N HCl. OPAP was found to exhibit very low solubility/degradation characteristics (similar to D2EHPA) and excellent loading characteristics with minimal zinc and sulfate co-extraction. OPAP seems to have the lowest sulfate carryover than any other extractant previously proposed for iron extraction from strong acidic solutions. In terms of stripping, a 70 g/l Fe(II) (as FeCl₂)/6 N HCl solution was found to be effective in producting 100 g/l total iron in the strip solution. For more information, contact G.P. Demopoulos, McGill University, Department of Mining and Metallurgical Engineering, 3610 University Street, Montreal, QC, Canada H3A 2B2; (514) 398-2046; fax (514) 398-4492; e-mail george@minmet.lan.mcgill.ca.     

MECHANISM OF EXTRACTION AND STRIPPING OF Fe(Ⅲ) WITH PRIMARY AMINE N1923 AS EXTRACTANT AND n-OCTANE AS DILUENT

Mechanism of extraction of Fe (III) from sulphate solution by primary amine N1923 andstripping of Fe loaded organic phase with dilute H_2SO_4 was investigated. The organic phasewas characterized by FT-IR and photon correlation spectroscopy. The composition of extractedspecies as well as the content of H_2O in organic phase were determined. The dependenceof both the rate of extraction and stripping on the formation of reverse micelle in primaryamine (N1923)system has been confirmed. It is shown that the extraction of Fe(III) by primary amine sulphate may be related to the adduct formation or cation exchange reaction underdifferent concentrations of H_2SO_4 in aqueous solution.     

Coprecipitation thermodynamics of iron(II-III) hydroxysulphate green rust from Fe(II) and Fe(III) salts

Iron(II-III) hydroxysulphate GR(SO₄²⁻) was prepared by precipitating a mixture of Fe(II) and Fe(III) sulphate solutions with NaOH, accompanied in most cases by iron(II) hydroxide, spinel iron oxide(s) or goethite. Its [Fe(II)]/[Fe(III)] ratio determined by transmission Mössbauer spectroscopy was 2±0.2, whatever the initial [Fe(II)]/[Fe(III)] ratio in solution. Proportion of Fe(OH)₂ increased when the initial [Fe(II)]/[Fe(III)] ratio increased, whereas proportion of α-FeOOH or spinel oxide(s) increased when this ratio decreased. GR(SO₄²⁻) is metastable vs. Fe₃O₄ except in a limited domain around neutral pH. Precipitation from solutions containing both Fe(II) and Fe(III) dissolved species seems to favour GRs formation with respect to stable systems involving iron (oxyhydr)oxides.     

预分散溶剂萃取法处理Cr(Ⅲ)废水(英文)

以2-乙基己基膦酸单2-乙基己基酯(HEHPEHE)为萃取剂,以及与其它萃取剂形成酸加酸、酸加碱、酸加中性混合萃取剂,通过考察萃取剂对废液中的Cr3+萃取分配比的影响,筛选出萃取Cr3+的适宜萃取剂HEHPEHE;采用预分散溶剂萃取技术对含Cr3+废液进行分离研究,以煤油为稀释剂,HEHPEHE为萃取剂,十二烷基苯磺酸钠(SDBS)为水性表面活性剂,吐温20(Tween-20)为油性表面活性剂,制备胶质液体泡沫CLAs。同时,为了研究预分散溶剂萃取技术萃取Cr3+废液的效果,考察了废液中的Cr3+浓度、胶质气体泡沫CGAs体积、萃取剂浓度、相比、阳离子表面活性剂十六烷基三甲基溴化铵(HTAB)浓度、阴离子表面活性剂SDBS浓度、表面活性剂Tween20浓度以及Cr3+废液的pH值等影响因素对Cr3+的萃取率影响,得到了萃取Cr3+的适宜条件;并用实际的含Cr3+废液进行检验,结果表明,在获得的适宜工艺条件下,经过二级萃取后,废水可以直接排放,Cr3+的萃取率超过99.9%。     

Treatment of arsenic ions from produced water through hollow fiber supported liquid membrane

Treatment of arsenic ions from produced water coming along with a gas separation plant in the Gulf of Thailand by hollow fiber supported liquid membrane (HFSLM) was studied. Cyanex^® 923 (a mixture of phosphine oxide), tri-n-butylphosphate (TBP), bis(2, 4, 4-trimethylpentyl) dithiophosphinic acid (Cyanex^® 301), tri-n-octylamine (TOA) and methyltrioctylammonium chloride (Aliquat 336) were used as the extractants. The stripping solution was sodium hydroxide. The concentration of the extractant in liquid membrane and concentration of sodium hydroxide were examined. In addition, the influence of various numbers of runs of the stripping solution through the HFSLM on the concentration of arsenic ions in the outlet stripping solution was observed. Of all the extractants used, 35% (v/v) Aliquat 336 attained high percentages of extraction and recovery of arsenic ions because it reacted with both undissociated arsenic (H₃AsO₃) and dissociated arsenics (H₂AsO₄⁻ and HAsO₄²⁻). Cyanex^® 923, TBP and TOA had low extractability since Cyanex^® 923 and TBP reacted only with undissociated forms while TOA reacted only with dissociated forms. In case of Cyanex^® 301, although it offered a relatively high percentage of extraction but very poor recovery due to this extractant formed very strong complex species with arsenic ions, which slowed down and made the stripping difficult. It was found that the percentage of arsenic recovery increased with the concentration of sodium hydroxide and was almost constant after 0.5 M due to the limitation of mass transfer area of the hollow fibers. After 3-cycle separation, the extraction and recovery of arsenic ions from produced water were 91% and 72%, respectively. Accordingly, the concentration of arsenic ions of 0.1201 ppm in produced water was observed, which was in accordance with the legislation discharge of industrial effluent in Thailand. More arsenic ions were recovered by increasing the numbers of runs of the recycling stripping solution through the HFSLM.     

Selective separation of Cu(II), Zn(II), and Cd(II) by solvent extraction

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 min 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).     

Kinetics of gadolinium extraction with D2EHPA and Cyanex301 using single drop column

The extraction kinetics of Gd(III) from the nitric acid medium using bis(2,4,4-trimethylpentyl) dithiophosphinic acid (Cyanex301) and 2-ethylhexyl phosphoric acid (D2EHPA) in kerosene solution were measured by the single drop technique. The influences of hydrogen ion concentration, gadolinium ion concentration, extractant concentration, column height, and nozzle diameter on the extraction rate were investigated. The forward rate equations for the gadolinium extraction with D2EHPA and Cyanex301 were obtained. Based on the experimental results, the forward extraction rate constant was calculated. With the increase of D2EHPA or Cyanex301 concentration, the drop rising diameter and the value of interfacial tension decrease in the studied system, which shows that D2EHPA or Cyanex301 has interfacial activity as a kind of surfactant. Also, the droplet diameter and interfacial tension decrease with the increase of aqueous solution acidity. The experimental results show that the D2EHPA extractant provides faster extraction rate in comparison with Cyanex301 extractant, and it would be useful in industrial continuous extraction process.     

Extraction and stripping of Cu and Ni from synthetic and industrial solutions of Sarcheshmeh Copper Mine containing Cu,Ni, Fe and Zn ions

The extraction and stripping of Cu and Ni ions from synthetic and industrial solutions of Sarcheshmeh Copper Mine containing Cu (770 mg/L), Ni (3200 mg/L), Fe (800 mg/L) and Zn (200 mg/L) were comprehensively investigated using D2EHPA, LIX 984, Cyanex 302, Chemorex CP 150 and Acorga 5774 diluted in kerosene. The influential parameters such as mixing speed and time, concentration of extractant, pH and temperature were considered in extraction stage. Furthermore, stripping of Cu and Ni was examined using different inorganic and organic acids (sulfuric, hydrochloric, nitric and citric acids) with different concentrations. The results indicated that the highest extractions of Cu and Ni occurred within 3 min, with the mixing speed of 500 r/min, 28 °C and A/O ratio of 1:1. Moreover, Cu was extracted by LIX 984 at the concentration of 10% (v/v), whereas Ni was extracted by Cyanex 302 at the concentration of 30% (v/v), efficiently. The optimal pH for Cu and Ni extraction is in ranges of 2−3 and 4−5, respectively. Cu and Ni were selectively extracted with the recoveries of 85%, 93% and 77%, 82% from synthetic and industrial solutions containing Ni, Cu, Zn and Fe ions, respectively. The results of optimal condition showed that 96% of Ni and 93% of Cu were stripped from the synthetic and industrial solutions. Finally, four elements Zn, Fe, Cu and Ni were extracted in three stages with D2EHPA, LIX 984 and Cyanex 302 extractants respectively with the least impurities.     

Removal and recovery of titanium (IV) from leach liquor of high-sulfur bauxite using calcium alginate microspheres impregnated with di-(2-ethylhexyl) phosphoric acid

In the leaching solution of high-sulfur bauxite roasted by sulfuric acid, a high concentration of aluminum presented along with titanium and iron. The present work was to remove Ti(IV) from the leach liquor by calcium alginate microsphere sorbent material (CA-P204) based on natural alginate impregnated with di-(2-ethylhexyl) phosphoric acid (D2EHPA) to purify leaching solution. Cation exchange and chelation make major contributions to the adsorption mechanism according to Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis. The results showed that Ti(IV) was successfully removed by the CA-P204 adsorbent from the Ti(IV)?Al(III)?Fe(III) ternary system with a dynamic column experiment. The removal rate of titanium was nearly 95% under optimal conditions and the maximum adsorption capacity was 66.79 mg/g at pH 1.0. Reusability of CA-P204 was evaluated over three consecutive adsorption/desorption cycles. The adsorption process was simple, low-cost, and had no waste discharge, suggesting that the CA-P204 was promising, efficient, and economical for removing Ti(IV) from high-sulfur bauxite leaching solution.     

Recycle use of phosphorous mixer extractant to extract indium

The stripping and regeneration of the loaded organic phase of phosphorous mixer extractant (PPD) were studied. The mixed solutions (3 niol/L HC1 +2 mol/L ZnCl2) were used as the stripping agent and more than 99% of indium can be stripped after three-stage stripping when the volume ratio of organic phase to stripping agent is 1:1. The organic phase can be recycled to use after regeneration with HC1. The parallel contrast experiments with D2EHPA (di-2-ethyl hexyl phosphoric acid) were carried out under the same conditions. The results show that the mixer extractant has good reusability and the stripping and regeneration of PPD are superior to those of DJ3HPA.     

用硫氰酸钾从季铵盐载金有机相中反萃金的研究

研究了应用硫氰权钾从CTAB-30%TBP（或30%正辛醇）-磺化煤油萃Au(Ⅰ）体系载金有机相的反萃取，以及反萃后的有机相的重复利用等，研究结果表明，应用3mol/LKSCN能够将载金有机相中（浓度为3g/LAu)90%左右的Au反萃入水相，3级反萃率接近100%，有机相经过5次循环利用后，对1g/LAu溶液的萃取率基本无变化，反萃入水相中的Au可能用NaBH4还原回收。     

Precursor solution prepared by evaporation deamination complex method for solvent separation of Mo and W by H2O2-complexation

An novel method on preparation of precursor solution for solvent separation of molybdenum (Mo) and tungsten (W) by hydrogen peroxide (H₂O₂)-complexation from the ammonium tungstate solution containing high Mo was studied. The precursor solution was obtained via evaporation deamination and H₂O₂-complex transformation processes. Then it was extracted with a mixture extractant of tri-alkyl phosphine oxide (TRPO) and tributyl phosphate (TBP) to separate Mo and W. The results indicated that the evaporation deamination complex method reduced the acid consumption by more than 90% in comparison with the traditional directly acid regulation complex method. The transformation rates of W and Mo were higher than 95% and the decomposition rate of H₂O₂ was less than 15% at a 1.8-1.9 times H₂O₂ dosage, 45-50 °C, initial pH of 1.80-1.90, and transformation volume ratio of 100% for 60 min in the H₂O₂-complexation transformation process. The minimum extraction rate of W was 2%, the maximum extraction rate of Mo was 82.6% and the highest separation coefficient was 76.7 in a single-stage extraction.     

The role of oxygen in the interaction of emeraldine base polyaniline with Cu(II) or Fe(III) ions in NMP solution

The influence of molecular oxygen in the interactions of emeraldine base form of polyaniline (EB-PANI) with Fe(III) or Cu(II) ions in 1-methyl-2-pyrrolidinone (NMP) solutions has been investigated by UV–vis–NIR, resonance Raman and electron paramagnetic resonance (EPR) spectroscopies. Through the set of spectroscopic results it was possible to rationalize the role of O₂ and to construct a scheme of preferential routes occurring in the interaction of EB-PANI with Fe(III) or Cu(II). Solutions of 4.0 mmol L⁻¹ EB-PANI with 0.8, 2.0 and 20 mmol L⁻¹ Fe(III) or Cu(II) ions in NMP were investigated and the main observed reactions were EB-PANI oxidation to pernigraniline (PB-PANI) and EB-PANI doping process by pseudo-protonation, or by a two-step redox process. In the presence of O₂, PB-PANI is observed in all Fe(III)/EB solutions and EB-PANI doping only occurs in solutions with high Fe(III) concentrations through pseudo-protonation. On the other hand, emeraldine salt (ES-PANI) is formed in all Fe(III)/EB solutions under N₂ atmosphere and, in this case, doping occurs both by the pseudo-protonation and two-step redox mechanisms. In all Cu(II)/EB solutions PB-PANI is formed both in the presence and absence of O₂, and only for solutions with high Cu(II) concentrations doping process occurs in a very low degree. The most important result from EPR spectra was providing evidence for redox steps. The determined Cu(II) signal areas under oxygen are higher than under N₂ and, further, the initial metal proportions (1:2:20) are maintained in these spectra, indicating that Cu(I) formed are re-oxidized by O₂ and, so, Cu(II) ions are being recycled. Consistently, for the solutions prepared under nitrogen, the corresponding areas and proportions in the spectra are much lower, confirming that a partial reduction of Cu(II) ions actually occurs.     

Selective Separation and Extraction of Vanadium (V) Over Manganese (II) from Co-Leaching Solution of Roasted Stone Coal and Pyrolusite Using Solvent Extraction

Based on the novel technology for selective separation and extraction of vanadium (V) over manganese (II) from co-leaching solution of roasted stone coal and pyrolusite using solvent extraction, the extraction effect of vanadium (V) and manganese (II) has been studied and many technical conditions have also been optimized. Meanwhile, countercurrent simulation experiments were conducted to verify the results of the experiments. The results indicated that with three countercurrent extraction stages, 99.21% vanadium (V) was extracted using 5% (v/v) N235 and 5% (v/v) secondary octyl alcohol at initial aqueous pH of 3.0 and O/A phase ratio of 1.0. Vanadium (V) could be completely stripped after three-stage countercurrent experiments with 20 wt.% NH₄Cl at O/A phase ratio of 1.0. The process flow sheet for the recovery of vanadium (V), as well as manganese (II), was proposed.     

Adsorption behavior of Sb(III) in single and binary Sb(III)—Fe(II) systems on cationic ion exchange resin: Adsorption equilibrium,kinetic and thermodynamic aspects

The present study dealt with the mechanism of competitive adsorption of Sb(III) and Fe(II) ions from a copper-containing aqueous solution on Purolite S957, a commercially available cationic ion-exchange adsorbent. Experiments were conducted using aqueous copper sulfate solutions containing either single or conjoint ions, using both sedentary and batch adsorption techniques to ascertain the sensitivity of the adsorption process to variation in pH, mass of resin, contact time, and temperature as well as establishing the optimal range of variables for maximum ion removal. The data from single ion adsorption tests were fitted by non-linear regression techniques to Henry, Langmuir, Freundlich, Temkin, and Dubinin—Radushkevich isotherm models. Freundlich isotherm for Sb(III) and Freundlich and Henry models for Fe(II) solutions best express the adsorption equilibrium data; while for binary ion electrolytes, the extended Freundlich model fitted the data satisfactorily. The kinetic model adequately describing adsorption was shown to be the pseudo-first-order, underscoring the dominant role of physical adsorption playing in the process. Thermodynamic parameters for the adsorption process reveal differences in the Sb(III) adsorption mechanism from single ion and Sb(III)—Fe(II) containing electrolytes. The adsorption of Sb(III) alone is endothermic, whereas the process becomes exothermic in the Sb(III)—Fe(II) system.     

D2EHPA—MPA—Fe^3＋协同萃取体系的动力学和界面化学研究

本文研究了协同萃取体系(D_2EHPA—MPA—Fe~(3+))的胶团形成热力学、界面特性、协萃效应和界面动力学(动力学控制机制和反应速率方程)研究发现,混合萃取体系中的D_2EHPA强烈地影响MPA的胶团形成热力学和界面吸附行为,得到了胶团生成常数(K_m)、胶团形成自由能(△G_m)和临界胶团浓度(CMC)的热力学参数D_2EHPA和MPA具有相反的界面吸附行为研究发现D_2EHPA—MPA混合萃取剂体系对Fe~(3+)产生了协萃效应动力学和界面化学的研究结果还证实了非胶束混合萃取体系的Fe~(3+)的萃取过程是受化学反应控制的,控制反应发生在界面上     

Molybdate/Al(III) composite films on steel and zinc-plated steel by chemical conversion

A molybdate(VI)-Al(III) chemical conversion process was developed as an alternative to the chromate processes. Steel and zinc-plated steel specimens were treated in the solutions of 0.16 mol l⁻¹ ammonium alum (AlNH₄(SO₄)₂ · 12H₂O) with small amounts of ammonium molybdate(VI) (0.002-0.016 mol l⁻¹ (NH₄)₆Mo₇O₂₄ · 4H₂O) at 60 °C for 10-30 min in an ultrasonic rinsing apparatus. The formed films were composed of oxyhydroxides containing Mo(V,VI), Al(III), Fe(II,III), and sulfate ions (and Zn(II) ions in the case of zinc-plated steel), and showed good corrosion resistance in an aerated 0.5 mol l⁻¹ NaCl-0.15 mol l⁻¹ H₃BO₃ solution (pH=7). The films macerated during the corrosion test, but they did not detach and functioned as a protective layer. This process may be useful in forming undercoats for paints and polymer coatings on steel and zinc-plated steel.     

用N503/TBP从碱性氰化液中萃取低浓度金

研究酰胺N503和TBP从碱性氰化液中萃取低浓度Au(Ⅰ),考察N503体积浓度、水相pH值、TBP浓度、NaCl浓度、改性剂种类和相比等因素对萃取率的影响.结果表明:当溶液的pH在7～11范围内,Au(Ⅰ)的萃取率均大于98%;当pH＞11后,Au(Ⅰ)的萃取率显著变小;尽管TBP的浓度对Au(Ⅰ)萃取率的影响较小,但提高TBP浓度可以提高萃取pH50值.对矿山浸出液的萃取结果表明,N503/TBP萃取体系对金具有良好的选择性, 其萃取金属氰配阴离子的由难至易的次序为Fe(CN)64-＞Ni(CN)42-＞Zn(CN)42-＞Cu(CN)32-＞Au(CN)2-.