Solvent Extraction Of Zinc Research Articles

Solvent Extraction of Zinc from Burnt Tyre Ash using Tri Butyl Phosphate

Solvent Extraction of Zinc from Burnt Tyre Ash using Tri Butyl Phosphate

Extraction and recovery of zinc from spent pickling solution: Experimental design and mechanism analysis

Solvent extraction of zinc with N, N-di(1-methylheptyl) acetamide (N503) from hot-dip galvanizing spent pickling solution is studied. The interaction between N503 concentration, extraction time, and phase ratio (O/A) is investigated using response surface methodology (RSM), and the experimental parameters are optimized as follows: the concentration of N503 is 50 % (v/v), the extraction time is 12 min, and the O/A is 16:5. The extraction efficiency of zinc is 82.12 %, and the separation coefficient (βZn/Fe) is 278.92 under the condition of single stage extraction. After four stages of countercurrent extraction, zinc is almost completely extracted from the aqueous phase. Additionally, it is found that zinc can be stripped effectively under the conditions of 0.4 mol/L HCl, stripping time of 10 min and O/A of 4:1. Also, the extraction mechanism of N503 is determined by electrostatic potential, FT-IR, and 1H-NMR spectroscopy, and the extraction complex is [CH3CONR2H]ZnCl3. In summary, a method for separating zinc from spent pickling solution has been developed, and it has a certain industrial application prospect.

Ultrasonic pretreatment-solvent extraction process for separating zinc from pickling waste liquid

Solvent extraction is the most important method for non-ferrous metals extraction and separation. In this work, solvent extraction of zinc from pickling waste liquid is investigated by using di(l-methyl heptyl) methyl phosphate (P350) diluted in sulfonated kerosene. Introduction of ultrasonic enhanced reduction of Fe3+ in the pretreatment stage of pickling waste liquid. The effect of ultrasonic time on the reduction process of Fe3+ is studied. Compared with traditional restoration, the required time for reduction is greatly shortened. The functional relationship of organic phase composition, concentration of extractant, phase contacts time and phase ratio function in single-stage extraction is studied. When concentration of extractant is 25 %, phase ratio is 4:1, the contact time is 15 min and the single-stage extraction efficiency of Zn2+ can reach 80.8 %. The extraction efficiency of Zn2+ reaches 99 % through three-stage countercurrent recovery. When O/A is 1:2, 1.6 mol/L HCl is used as the stripping agent and the stripping efficiency of P350 can reach 90.4 %. In addition, extraction stoichiometry is determined by slope analysis and extraction mechanism is analyzed by FT-IR and mass spectrometry. Overall, this work provides a new solution in the extraction of zinc from pickling waste liquid.

Solvent Extraction of Zinc from a Bioleaching Solution by Modification of D2EHPA: Optimization and Thermodynamic Studies

In this work, zinc extraction from an industrial leach solution was investigated by saponified di(2-ethylhexyl)phosphoric acid (D2EHPA). The solution obtained was from a bioleaching process of a low-grade lead-zinc sulfide ore that contained 50 g/L of zinc and 6.3 g/L of iron. The selective and high Zn(II) extraction yield were obtained by modification of D2EHPA in a proposed two-step process. Firstly, a significant amount of iron (87%) was removed as sodium-jarosite via precipitation from the pregnant leaching solution (PLS) prior to zinc extraction, and secondly, the effective parameters involved in zinc extraction including the contact time, saponification degree, type of saponifier, stirring speed, pH, temperature, D2EHPA concentration, and phase ratio (A:O) were investigated. The results obtained showed that 98.4% of zinc could be extracted under the optimum conditions, i.e. 20% D2EHPA, 15% saponification degree, 650 rpm, pH 2, and an A:O ratio of 1:1 at the ambient temperature (25 ± 2 °C) during 90 s; it was 25% higher than using non-saponified D2EHPA under the same conditions. Moreover, while one theoretical step was required for the complete extraction of zinc by saponified D2EHPA, the required number of steps using D2EHPA was about three. Therefore, the advantages of the process would be two-fold: reducing the number of extraction stages and no need for neutralizing the raffinate in every extraction stage.

Solvent Extraction of Zinc(II) and Manganese(II) with 5,10,15,20-Tetraphenyl -21H,23H-Porphine (TPP) through The Metal Exchange Reaction of LEAD(II)-TPP (Dept.M)

An investigation was carried out on the extraction of aqueous Zn(II) and Mn(π) with a hydrophobic porphyrin (5,10,15,20-tetraphenyl-21H,23H porphine, TPP) through a metal exchange reaction of Pb(π)-TPP. The distribution ratios (D) of these metals were found to be independent of the Pb(π) concentration in the aqueous phase. Pb(π) in the aqueous phase acted as a catalyst which promoted the metal-TPP complexation.

Effect of pH, Anions and Acids on the Extraction of Zinc (II) from Aqueous media using Acetylacetone Solutions of Sulphamethoxazole

The challenge of heavy metal contaminations have been remediated to a certain level by the application of several methods of their extractions from aqueous media. Solvent extraction of zinc (II) ions from buffered aqueous solutions into acetylacetone solution of sulphamethoxazole as a function of pH and concentration of anionic substances and certain mineral acids were investigated in this work. The aqueous medium was prepared by dissolving 1.0995g of ZnSO4.7H2O in 250 ml volumetric flask to form 1000mg/L solution. 50mg/L working concentration was prepared from the 1000mg/L by dilution method. The organic phase is 0.5 M Sulfamethoxazole solution prepared by dissolving 12.664g of the salt in 100 ml acetylacetone. 2 ml each of aqueous and organic phases were taken with micro pipette and transferred into a set of 20 ml extraction bottle and the mixture was agitated mechanically for about 30 minutes. The mixture was allowed to settle and separate into two layers. 1 ml of the aqueous phase was taken, diluted and analysed for Zn (II) ions using atomic absorption spectrophotometer at a wavelength of 213.9. The results obtained on studying the effect of pH showed that Zn (II) ion was quantitatively extracted between pH of 7.0 to pH 8.0. The highest percentage extraction 85.37% was observed at pH 8.0 in acetylacetone solution of sulphamethoxazole. Increase in pH above 8.0 resulted in a steady decrease in the extraction of Zn (II). Studies on the effect of anions showed significant extractions which changes as the anions concentrations increased. All studies on mineral acids also showed significant extractions and increase in the concentrations of the acids affected the percentage extraction. Generally Zinc (II) ions can be extracted quantitatively in mild acids and anions concentrations when buffered from slightly acidic pH ranges of 6.0 to slightly alkaline pH values of 8.5.

The use of carbon-dioxide to enhance the solvent extraction of zinc from ammonia leaching solutions of blast furnace dust

In this study, the enhanced extraction of zinc from a blast furnace dust (BFD) ammonia leaching solution via carbon dioxide (CO2) was investigated. 1-Benzoyl-2-nonyl ketone (commercially known as Mextral54–100) and tri-alkyl phosphine oxide (TRPO) were used as the extractant and synergistic extractant, respectively. The effects of different operational factors, such as the CO2 pressure, extractant concentration, phase ratio, and extraction temperature, were examined to optimize selective and quantitative zinc extraction. The loaded organic phase was stripped using sulfuric acid and waste electrolyte. Quantitative zinc extraction was achieved in two stages using 1.2 mol/L Mextral54–100 and 0.2 mol/L TRPO at an initial pH of 8.0, CO2 at 0.2 MPa, and an aqueous:organic (A:O) ratio of 2:1. The loaded organic phase, which contained 0.08 mol/L zinc, could be stripped in a single stage using 1.6 mol/L H2SO4 at a phase flow ratio of A/O = 1:1 to create a loaded strip solution that contained 5.5 g/L zinc. Zinc extraction from BFD with the ammonia leaching solution was enhanced by CO2 addition. Fourier-transform infrared spectroscopy confirmed that CO2 could prevent the co-extraction of ammonia into the synergistic system of the Mextral54–100/TRPO mixture. Based on the experimental results, a flowsheet for the recovery of zinc from BFD was developed and tested. The extents of zinc leaching, extraction, and stripping were ~ 91%, 97%, and 99%, respectively.

Solvent extraction of zinc from chloride solutions using dialkyl derivatives of 2,2′-bibenzimidazole as extractants

Four new 1,1′-dialkyl-2,2′-bibenzimidazoles were used to extract zinc(II) from acid chloride solutions at various concentrations of chloride and hydrogen ions. In low acidity media (pH > 2), the maximum zinc(II) extraction with the compounds is observed at chloride concentrations in the range 0.7–1.8 M. Zinc(II) ions are extracted as neutral (ZnCl2)mLn complexes (L = extractant) in which the m:n ratio varies from 1:2 to 3:3, depending on the metal-to-extractant molar ratio in the extraction media. In strongly acidic systems, anionic zinc(II) chloro-complexes may be extracted from aqueous solutions by protonated bibenzimidazoles as (LH+)2(ZnCl42−) or/and (LH+)(ZnCl3−) ion pairs. In weakly acidic media, at [Cl−] < 2 M, Zn(II) can be separated from Cd(II), Cu(II), and Ni(II) by 1,1′-didecyl-2,2′-bibenzimidazole, the best extractant from the tested dialkyl derivatives of 2,2′-bibenzimidazole. From the feed containing 26 g/L Zn(II), over 80% of zinc(II) ions is selectively separated after four extraction stages. 1,1′-Didecyl-2,2′-bibenzimidazole can be used for the selective separation of pure Fe(III) and Zn(II) from acidic chloride solutions. At a high chloride concentration (6 M) and at 0.5–0.8 M HCl in the aqueous feed, Fe(III) is efficiently transferred into the organic phase in the presence of Zn(II) and is then easily stripped off with water. Zn(II) can be completely removed from the iron-free raffinate after this aqueous solution is acidified to 1.5 M HCl.

Solvent extraction of zinc from synthetic Zn-Cd-Mn chloride solution using D2EHPA: Optimization and thermodynamic studies

Abstract The extraction of zinc in the presence of manganese and cadmium from chloride solution with di 2 ethyl hexyl phosphoric acid (D2EHPA) in kerosene diluent were comprehensively investigated. The extraction experiments were carried out in order to determine the influential parameters in the conditions of A:O ratio of 1:1, pH range of 1–6, temperatures of 30 °C, 40 °C and 50 °C in an aqueous solution with concentrations of 5 g/L of zinc, manganese and cadmium. The variety of influential parameters in the process such as equilibrium pH, concentration of D2EHPA, temperature, contact time, initial concentration of ions and also thermodynamic parameters of zinc extraction in chloride solution were precisely evaluated. The results showed that in the optimal condition of pH = 2.5–3, temperature 40 °C and [D2EHPA] = 10 v/v, the extraction of Zn, Mn and Cd were 97%, 14% and 3% respectively. ΔpH0.5Zn-Mn and ΔpH0.5Zn-Cd in this condition respectively equal to 2.5 and more than 5.25. Also, the study indicated that the predominant zinc species extracted by D2EHPA was ZnCl+. Based on thermodynamic studies, the values of ΔHo, ΔSo and ΔGo for zinc extraction in condition of temperature 40 °C and [D2EHPA] = 10 v/v are 25.65 kJ.mol−1, 79.20 J·K−1·mol−1 and 0.86 kJ·mol−1 respectively. Furthermore, the results showed that under constant concentration of D2EHPA, changes in the initial concentrations of Zn, Mn and Cd in the chloride solution were most effective in their separation.

Solvent extraction of zinc from sulphate leaching solution of a sulphide-oxide sample using D2EHPA and Cyanex 272

ABSTRACTSolvent extraction of zinc from sulphate leach solution obtained from the treatment of a sulphide-oxide sample, was investigated using D2EHPA and Cyanex 272 diluted in kerosene in a batch reactor. According to the results, D2EHPA exhibited the higher extraction efficiencies than Cyanex 272 at the organic/aqueous ratio of 1:1. The optimum concentration and pH for D2EHPA and Cyanex 272 were distinguished to be 0.5 mol/L and 2.5, and 0.035 mol/L and 3.5, respectively. Under these conditions, extraction efficiency was found to be ∼75% for D2EHPA against 41% for Cyanex 272. The plot of log D versus log [D2EHPA] confirmed the presence of 1 mole D2EHPA in dimeric form for 1 mole Zn in the extraction system. Thermodynamic data showed that the zinc extraction process is endothermic. For D2EHPA, two-stage simulated counter-current extraction experiments were performed on the basis of the McCabe-Thiele diagram and the extraction percentage of zinc was found to be about 88%. The synergistic effect of Cyanex 272 and TBP with D2EHPA was particularly investigated. It was found that the mixture of 80% D2EHPA and 20% Cyanex 272 exhibited the best synergistic effect for Zn-extraction with a synergistic coefficient of 1.04.

Efficiently enriching zinc(II) from and into ammonium chloride media with species regulation and Aliquat336

Abstract Solvent extraction of zinc(II) from and into ammoniacal chloride media with trialkylmethylammonium chloride (Aliquat336) has been investigated in the presence and absence of trioctylphospine oxide (TOPO). The results indicate that zinc extraction with Aliquat336 is sensitive to pH and ammonia concentration of ammoniacal chloride solutions. The extraction efficiency of zinc increases with increasing chloride concentration due to the formation of ZnCl 3 − species. Meanwhile, zinc can be effectively stripped with ammoniacal solutions from the loaded organic phases because of the formation of Zn(NH 3 ) 4 2+ species. The Aliquat336 mixed with TOPO can induce a synergistic effect on zinc extraction but antagonistic effect on ammonia stripping of zinc. Therefore, through adjusting the coordination equilibrium of zinc species in extraction and stripping processes, the efficient enrichment of zinc ions from and into the ammoniacal chloride media can be achieved by solvent extraction, which is beneficial for zinc recovery from the complex ore resources.

Direct enrichment of zinc(II) from and into ammoniacal media with commercialLIX84I

Abstract Solvent extraction of zinc(II) from and into ammoniacal media has been investigated using commercial LIX84I extractant. The effects of aqueous solution pH, total ammonia concentration and temperature on extraction of zinc(II)and ammonia stripping of loaded organic phases were examined. The extraction and stripping behaviors of zinc was also compared in the absence and presence of tributyl phosphate (TBP). The results indicate that LIX84I presents a good potential for zinc extraction in the ammonical solution. However, TBP has an antagonistic effect on zinc extraction with LIX84I. The extraction behavior of Zn(II) presents a special swing phenomenon in the both cases with and without TBP. The slope analysis and IR spectra indicate that each zinc ion can coordinate with two LIX84I molecules, whereas TBP molecules could bond with the LIX84I molecules, thus depressing zinc extraction. The zinc loaded organic phases can be effectively stripped with the ammoniacal media, especially increasing the ammonia concentration. Zinc stripping is more easy for the mixed system with TBP than the individual LIX84I system. Moreover, the extraction of zinc is an exothermic process, whereas the ammonia stripping of zinc is an endothermic process. The extraction and stripping isotherms indicate that the direct enrichment of zinc(II) from and into ammoniacal media can be achieved with the commercial LIX84I. These results are helpful for the hydrometallurgical recovery of zinc from the non-traditional resources.

Solvent extraction of zinc(II) from ammonia leaching solution by LIX 54-100, LIX 84 i and TOA

Solvent extraction of zinc(II) from ammonia leaching solution by LIX 54-100, LIX 84 i and TOA

Synergistic extraction of zinc from ammoniacal/ammonia sulfate solution by a mixture of β-diketone and 2-hydroxy-5-nonylacetophenone oxime

The solvent extraction of zinc from ammoniacal/ammonium sulfate solutions using a mixture of β-diketone, 1-benzoyl-2 nonyl ketone (Mextral54-100, HA), and 2-hydroxy-5-nonylacetophenone oxime (Mextral 84H, HR) in sulphonated kerosene has been investigated. The effects of different ratio of extractants, extractants concentration, aqueous pH, total ammonia concentration and temperature on zinc extraction were examined. The results indicate that the mixture of Mextral54-100 and Mextral 84H shows evident synergistic effects on zinc extraction, and zinc is extracted as ZnAR by the mixed extractants. As the molar fraction of HR rises, the co-extraction ammonia content increases constantly and reaches a maximum value at χ(HR) 0.5. The extraction efficiency decreases dramatically with the increase of aqueous pH and total ammonia concentration, indicating that the formation of zinc amine complexes depresses the ligand exchange reaction. The thermodynamic parameter ΔH shows that the extractions of zinc by both extraction systems are exothermic driven. FT-IR studies confirm that the ammonia molecules can be co-extracted into synergistic adducts.

Solvent extraction of zinc, manganese, cobalt and nickel from nickel laterite bacterial leach liquor using sodium salts of TOPS-99 and Cyanex 272

The extraction and separation of zinc, manganese, cobalt and nickel from nickel laterite bacteria leach liquor were carried out using sodium salts of TOPS-99 and Cyanex 272 in kerosene. The unwanted metal ions were removed by precipitation method and solvent extraction was used to extract/separate Zn, Mn, Co and Ni. The nickel laterite leach liquor which was obtained from bioleaching of chromite overburden samples contained 3.72 g/L Fe, 2.08 g/L Al, 0.44 g/L Ni, 0.02 g/L Co, 0.13 g/L Mn, 0.14 g/L Zn and 0.22 g/L Cr. From this leach liquor, 100% Fe, 96.98% Al and 70.42% Cr were removed by precipitation with CaCO3 at pH 4.4 followed by precipitation of remaining Al and Cr with 50% ammonia at pH 5.4. After precipitation, the extraction of Zn from the Fe, Al and Cr free leach liquor was carried out with 0.1 mol/L TOPS-99 followed by Mn extraction with 0.04 mol/L NaTOPS-99. The yields of Zn and Mn were 97.77% and 95.63%, respectively. After Mn extraction, cobalt was removed from the leach liquor using 0.0125 mol/L NaCyanex 272 and finally nickel extraction was carried out using 0.12 mol/L NaTOPS-99 with 99.84% yield. The stripping of loaded organic (LO) phases were achieved with dilute H2SO4.

Highly Selective Solvent Extraction of Zn(II) and Cu(II) from Acidic Aqueous Chloride Solutions with Mixture of Cyanex 272 and Aliquat 336

Selective solvent extraction of zinc(II) and copper(II) from aqueous acidic chloride solutions by mixture of bis(2,2,4-trimethylpentyl)phosphinic acid (Cyanex 272) and trioctymethylammonium chloride (Aliquat 336) in kerosene has been investigated. Detailed studies have been conducted by varying pH, hydrochloric acid, and chloride concentrations in aqueous phase as well as extractants concentration in organic phase. A full and high selective solvent extraction of zinc(II) over copper(II) from acidic chloride solutions has been achieved by 0.1 M Cyanex 272 and 0.06 M Aliquat 336 in kerosene while efficient Zn(II) stripping has been performed by using 1 M sulphuric acid. The following selectivity coefficients of zinc(II) over Cu(II) (SZn/Cu) during their solvent extraction from 1 M NaCl at pH 0.5 by Cyanex 272, Aliquat 336, and their mixture were found to be equal to: 1.7, 62, and 3162, respectively.

Beneficiation of a Nigerian sphalerite mineral: Solvent extraction of zinc by Cyanex®272 in hydrochloric acid

The extraction of Zn(II) from aqueous chloride sphalerite leached liquor using bis(2,4,4-trimethylpentyl)phosphinic acid or Cyanex ®272 in kerosene has been studied. The results of fundamental studies on solvent extraction of synthetic solutions of Zn(II) showed that extraction of metal ions increased with increasing pH, extractant concentration and temperature. The stoichiometry of the extracted metal species by Cyanex ®272 with Zn(II) was 1:1. The apparent standard molar enthalpy (∆H°), molar entropy(∆S°) and Gibb's free energy(∆G°) of 26.81 ± 0.11 kJ/mol, 107.63 ± 0.05 J mol –1 K –1 mol –1 and − 5.48 ± 0.13 kJ/mol were calculated for the process respectively. These values showed that Zn(II) extraction by Cyanex ®272 is thermodynamically favourable. The number of the theoretical stages for this process evaluated by the McCabe-Thiele diagram was six. An extraction efficiency of 95% Zn(II) was obtained with 0.047 mol/L Cyanex ®272 in kerosene from an initial sphalerite leach liquor containing mainly 603.4 mg/L Zn, 121.4 mg/L Fe and 16.3 mg/L Pb. The Pb(II), Ag(I), Cu, Sn, and Al (less than 5 mg/L) were firstly separated by cementation with Zn granules and this was followed by Iron removal by precipitating with 4 mol/L ammoniacal solution to a pH of 3.5 at 25 °C ± 2 °C. A 0.1 mol/L HCl was found to be adequate for the stripping of about 95% of Zn from the organic phase. The stripped Zn(II) solution was recovered as zinc oxide (ZnO) via precipitation with sodium hydroxide followed by calcination at 600 °C during 120 min. A practicable hydrometallurgical scheme summarising the operational procedures used for the extraction of Zn(II) and Pb(II) from the sphalerite ore was presented.

Synergistic extraction of zinc from ammoniacal ammonia sulfate solution by a mixture of a sterically hindered beta-diketone and tri-n-octylphosphine oxide (TOPO)

The solvent extraction of zinc from ammoniacal ammonium sulfate solution is studied using a mixture of a sterically hindered β-diketone, 1-(4′-dodecyl)-phenyl-3-t-butyl-1,3-octadione (HR), and tri-n-octylphosphine oxide (TOPO) in sulphonated kerosene. TOPO and HR show evident synergistic effects on the solvent extraction of zinc and the optimum composition of TOPO and HR is 50% v/v (molar ratio TOPO: HR = 2). Zinc extraction, as Zn 2+ ion decreases with an increase of initial pH value and total ammonia concentration and increases with an increase of phase ratio, has no relationship with the zinc concentration of the aqueous phase. Based on batch scale equilibrium results, a continuous extraction of zinc from simulated leaching solution and zinc oxide ore ammoniacal leaching solution was carried out in a mixer-settler unit containing two extraction stages and one stripping stage. The two-stage extraction efficiencies of zinc are 86% and 85% for the simulated and ore leaching solutions, respectively, whereas the stripping efficiency is 85% for both cases. By applying an “ammonia leaching–solvent extraction–electrowinning” process, extra-pure zinc metal (Zn > 99.995%) was obtained.

Solvent extraction of zinc from zinc sulfate solution

The extraction of zinc from zinc sulfate solution was investigated, using 20% saponified D2EHPA as an extractant and 260# sulfonate kerosene as a diluent. The solution was stirred for 8 min at phase ratio (V o/V a) 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 zinc from ammoniacal/ammonium chloride solutions by a sterically hindered β-diketone and its mixture with tri-n-octylphosphine oxide

The extraction of zinc from ammoniacal/ammonium chloride solutions using a sterically hindered β-diketone, 4-ethyl-1-phenyl-1,3-octadione (XI-55, HA) as the extractant has been investigated in the presence or absence of tri-n-octylphosphine oxide (TOPO, B). The results indicate that the mixture of XI-55 and TOPO shows evident synergistic effects on zinc extraction. Zinc is extracted as ZnA 2B by the mixture and the stability constant of ZnA 2B is 2.08. Thermodynamic parameters Δ H, Δ S and Δ G are determined, which shows that the extractions of zinc by both XI-55 extraction system and the XI-55–TOPO synergistic extraction system are exothermic driven. The concentration of total ammonia has great influence on the extraction constants and distribution ratio for both extraction systems. FT-IR studies on zinc loaded organic phases confirm the non-extractability of zinc ammine complexes.