Synergistic extraction and separation of valuable elements from high-alumina fly ash with carbochlorination method

A novel process was proposed for synergistic extraction and separation of valuable elements from high-alumina fly ash.A thermodynamic analysis revealed that to achieve effective carbochlorination,it is crucial to conduct carbochlorination of the fly ash within the temperature range from 700 to 1000℃.The experimental results demonstrated that under the optimal conditions,the carbochlorination efficiency for Al,Si,Ca,Ti,and Mg exceeded 81.18%,67.62%,58.87%,82.15%,and 59.53%,respectively.The XRD patterns indicated that Al and Si in the mullite phase(Al_(6)Si_(2)O_(13))were chlorinated during the carbochlorination process,resulting in the formation of mullite mesophases(Al_(4.75)Si_(1.25)O_(9.63) and Al_(1.83)Si_(1.08)O_(4.85)).After the carbochlorination process,Al was accumulated as AlCl_(3) in the condenser,while SiCl_(4) and TiCl_(4) were enriched in the exhaust gas,and CaCl_(2),MgCl_(2),and unreacted oxides remained in the residue for further recycling.

Synergistic solvent extraction of boric acid by trioctylamine and 2-hydroxydodecanoic acid

A synergistic solvent extraction system comprising trioctylamine(TOA)and ligands with hydroxyl and carboxyl groups can efficiently recover boric acid(H_(3)BO_(3))and separate boron isotopes.However,the structure of ligands might impact H_(3)BO_(3) extraction,boron isotope separation,and solvent loss,which has not been thoroughly investigated.This study initially evaluated the influence of ligand's type,pKa,and substituents on H_(3)BO_(3) extraction efficiency,as well as the impact of the B_((4))-O structure(boron is bound to four oxygen atoms)in the organic phase on isotope separation efficiency.Subsequently,by synthesizing the highly hydrophobic 2-hydroxydodecanoic acid(HYA),the extraction performance and mechanism of the TOA/HYA system were investigated.The findings highlight the superior extraction efficiency when employing di-phenolic hydroxyl,phenolic hydroxyl + carbinol hydroxyl,and alcoholic hydroxyl + carboxyl ligands compared to phenolic hydroxyl + carboxyl,phenolic hydroxyl + ethanol hydroxyl,diol hydroxyl,and dicarboxylic ligands.The organic phase anion complex,exclusively comprising the B_((4))-O structure,enhances isotope separation effectiveness.The TOA/HYA system achieves an 80%single-stage extraction efficiency for H_(3)BO_(3).H_(3)BO_(3) and HYA are extracted into the organic phase at a ratio of 1:2,with the anion complex solely containing the B_((4))-O structure.This study paves the way for the construction of novel boric acid extraction and boron isotope separation systems.

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

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

Synergistic extraction of cerium from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester and Di-(2-ethyl hexyl) phosphoric acid as extractant

Synergistic extraction of cerium（IV） from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester（HEH/EHP, HL） and Di-（2-ethyl hexyl） phosphoric acid（HDEHP, HA） as extractant was investigated.The results indicated that the maximum synergistic enhancement coefficients were obtained at the mole fraction of HEH/EHP=0.6, and cerium（IV） was extracted into organic phase in the form of Ce（SO4）0.5HL2A2.A cation exchange mechanism was proposed for the synergistic extraction of Ce（IV）.The equilibrium constants and thermodynamic functions such as △G, △H, and △S were determined in the extraction of Ce（IV） from sulfuric medium using mixture of HEH/EHP and HDEHP.

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

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

Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-(2-ethylhexyl) phosphoric acid from sulfuric acid medium

The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.

Direct extraction of Mo(Ⅵ) from sulfate solution by synergistic extractants in the rotation column

Direct extraction of molybdenum from sulfate solution with synergistic extractants(mixture of D2EHPA and TBP)was studied in the rotation column.The influence of extractant concentration and initial pH of aqueous phase was studied in the bench scale experiments.The outcomes demonstrated that the synergistic solvent extraction enhances the constancy of the extracted complexes for transfer into the organic phase.In the continuous experiments,the effect of different operating parameters such as speed of agitation,inlet solvent flow rate and inlet aqueous flow rate on the holdup,mean drop size,drop size distribution,slip and characteristic velocities and extraction percentage were examined.Modified correlations were proposed for prediction of hydrodynamic parameters with consideration of reaction extraction condition in the rotation column.Furthermore,these correlations were compared with the experimental data.According to the results,the direct extraction of Mo(Ⅵ)from aqueous solution and sulfuric media with extraction efficiency of 90.4%was obtained at higher rotor speed(240 r·min–1 rpm)in this column.

Phase separation in solvent extraction of cobalt from acidic sulfate solution using synergistic mixture containing dinonylnaphthalene sulfonic acid and 2-ethylhexyl 4-pyridinecarboxylate ester

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).

Synergistic extraction of rare earths by mixture of HDEHP and HEH/EHP in sulfuric acid medium

The extraction of RE（Ⅲ） （RE=La, Nd, Sm, Gd） in sulfuric acid medium using the mixture of HDEHP（H2B2） and HEH/EHP（H2L2） was investigated. The synergistic enhancement coefficient（R） was calculated for La （1.96）, Nd（3.52）, Sm（5.96）, and Gd（5.71）, respectively, at pH=2.0, and it was seen that the R increased with the increase of aqueous quilibrium pH. The configuration of the extracted complexes was considered to be RE（SOa）xH2x（HB2）3 with HDEHP, RE（SOa）xH2x（HL2）3 with HEH/EHP, and RE（HB2）2（HL2） with their mixture as the extractant with the slope method. The equilibrium constants and stability constants were calculated. A cation exchange mechanism was proposed as well.

THE SYNERGISTIC MECHANISM OF SOLVENT EXTRACTION OF GOLD IN HCl MEDIA WITH TOA AND TOPO

The mechanism of synergistic extraction of gold in HCl media was researched with tri n octyl amine(TOA) and tri n octyl phospine oxide(TOPO). It was determined that the composition of synergistic extract is (TOAHTOPO)AuCl 4; the constant of synergistic extracting equilibrium is 10 9.20 ; and the synergistic reaction is exothermic with -17.187 kJ/K·mol of Δ H 298 . The extraction mechanism was also studied by the IR spectra and UV spectra. It is found that the extraction mechanism belongs to ion association type.

Synergistic Extraction of Gallium from Sulfate Solution

A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plusHX, was proposed and tested for recovering gallium from sulfatesolution. It was found that the extraction capacity of DEPHA forgallium from sulfate solution could be enhanced significantly due tothe synergistic effect of acidic extractant HX. Gallium extraction isnegligible below pH 0 and highly sensitive to pH of aqueous phase inthe range from 0 to 1, and satisfactory extraction can be gained atpH＞1. More than 96/100 Ga Extraction was obtained using 15/100 DEHPAplus 2/100 HX.

Synergistic Extraction of Rare Earth Ions by 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and Trioctylphousphine Oxide in Paraffin Wax

The paraffin wax was used as an organic solvent for 1 phenyl 3 methyl 4 benzoyl 5 pyrazolone (PMBP) and trioctylphousphine oxide (TOPO) in the extraction of rare earth ions (La 3+ , Pr 3+ , Eu 3+ , Yb 3+ and Ho 3+ ) at 70℃. The composition of the extracted specices were given as RE(PMBP) 3(TOPO) 2 by means of slope analysis. The variation of the synergistic extraction equilibrium constant ( K sex ) was studied at 55℃～70℃. The thermodynamic data obtained showed that the synergistic extraction of rare earth ions by PMBP and TOPO in molten paraffin wax is exothermic and the extracted complexes were formed by TOPO bonding to the outer sphere hydration.

Engineering Multi‑field‑coupled Synergistic Ion Transport System Based on the Heterogeneous Nanofluidic Membrane for High‑Efficient Lithium Extraction

The global carbon neutrality strategy brings a wave of rechargeable lithium‐ion batteries technique development and induces an ever-growing consumption and demand for lithium(Li).Among all the Li exploitation,extracting Li from spent LIBs would be a strategic and perspective approach,especially with the low energy consumption and eco-friendly membrane separation method.However,current membrane separation systems mainly focus on monotonous membrane design and structure optimization,and rarely further consider the coordination of inherent structure and applied external field,resulting in limited ion transport.Here,we propose a heterogeneous nanofluidic membrane as a platform for coupling multi-external fields(i.e.,lightinduced heat,electrical,and concentration gradient fields)to construct the multi-field-coupled synergistic ion transport system(MSITS)for Li-ion extraction from spent LIBs.The Li flux of the MSITS reaches 367.4 mmol m^(−2)h^(−1),even higher than the sum flux of those applied individual fields,reflecting synergistic enhancement for ion transport of the multi-field-coupled effect.Benefiting from the adaptation of membrane structure and multi-external fields,the proposed system exhibits ultrahigh selectivity with a Li^(+)/Co^(2+)factor of 216,412,outperforming previous reports.MSITS based on nanofluidic membrane proves to be a promising ion transport strategy,as it could accelerate ion transmembrane transport and alleviate the ion concentration polarization effect.This work demonstrated a collaborative system equipped with an optimized membrane for high-efficient Li extraction,providing an expanded strategy to investigate the other membrane-based applications of their common similarities in core concepts.

Neutral Complex Extraction and Synergistic Extraction of Macrolide Antibiotics

Based on the theory of reactive extraction, new solvent systems were developed to replace butylacetate for extraction of macrolide antibiotics (erythromycin, kitasamycin, spiramycin meleumycin etc.). A new neutral complex solvent extraction system, fatty alcohol-kerosene (marked by El), was used for extraction of erythromycin, one of the macrolide antibiotics. The extraction equilibrium equation is obtained, and the extraction distribution is as followsD = exp (-36.33×103/RT + 18.77)[B](o)1.1/(1 + 108.07-PH)The effects of several parameters on extraction equilibrium were investigated. Furthermore, a new synergistic extraction system (marked by E2) was developed, in which another solvent was used as synergistic agent to replace the diluent kerosene in the neutral complex extraction system. Based on these new extraction systems, an improved process for extraction of erythromycin was developed, showing remarkable advantages in technology and economics owing to its low solvent consumption of 3kg per billion unit compared with 9—10 for butylacetate. The recovery process of solvent from raffinate may be eliminated.

Synergistic extraction of praseodymium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline

The synergistic extraction of Pr^3＋ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester （P507, HL） and 8-Hydroxyquinoline （HQ） in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3＋ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3＋.

Study on the Synergistic Extraction of Ytterbium with 1－Phenyl－3－Methyl－4－（α－Furoyl）－5－Pyrazolone and Neutral Extractant

The extraction of Yb3+ by HA [1-phenyl-3-methyl-4-(α-furoyl)-5-pyrazolone] and by HA in combination with a neutral extractant B in toluene have been studied, where B represents n-butyloctyl sulfoxide (BOSO), n-pentylhexyl sulfoxide (PHSO), ethyl-n-dodecyl sulfoxide (EDSO), diphenyl sulfoxide (DPSO) or TBP. The composition of the synergistic extraction complexes have been shown to be YbA3·B and their extraction equilibrium constants have been determined separately.

DOUBLE SYNERGISTIC EFFECTS AND EXTRACTION KINETICS OF A MICELLE MIXED EXTRACTANT SYSTEM I DOUBLE(KINETIC AND THERMODYNAMIC)SYNERGISTIC EFFECTS AND EXTRACTION MECHANISMS

The equilibria and kinetic characteristics of a micelle mixed extractant system-D2 EHPA-MPA（MPA-monoalkyl phosphoric acid with long carbon chain and micellization）in extractionof the Al3+ions were studied.It was found that the system has double synergistic effects on theextraction of the Al3+ions.The compositions of the synergistic complexes were determined andthe synergistic reaction equations were obtained.

SYNERGISTIC EXTRACTION OF Cd(Ⅱ)WITH PRIMARY AMINE N-1923 AND NEUTRAL ORGANOPHOSPHORUS REAGENTS

The synergistic extraction of Cd(Ⅱ)with primary amine N-1923 and neutral organophosphorus reagents(TBP,DBBP,B)from hydrochloric acid has been investigated at μ=0.5,t=25℃.The compositions of the synergistic extraction complexes and the mechanism of the synergistic extraction have been determined by the methods of slope and constant mole. The synergistic extraction complexes with composition(RNH_3Cl)_2·CdCl_2·B have been demonstrated.The synergistic extraction reactions and additional reaction of Cd(Ⅱ)have been proposed as follows: CdCl_2+2RNH_3Cl_(o)+B_(o)(RNH_3Cl)_2·CdCl_2·B_(o) (RNH_3Cl)_3·CdCl_(2(o)+B_(o)(RNH_3Cl)_2·CdCl_2·B_(o)+RNH_3Cl_(o) In addition,the equilibrium constants and the thermodynamic functions of the synergistic ex- traction reactions have been calculated.The IR and NMR spectra of the synergistic ext-ac- tion complexes of Cd(Ⅱ)have been studied as well.

EXTRACTION KINETICS,SYNERGISTIC EFFECTS AND INTERFACIAL CHEMISTRY FOR D_2 EHPA MPA-Fe^(3+) MIXED EXTRACTION SYSTEM

The thermodynamics of micella formation,interfacial characteristics,synergistic effects and interfacial kinetics for synergistic extraction system D_2 EHPA-MPA-Fe^(3+) have been studied.It was found that D_2EHPA in the mixed system strongly exhibits the effect on the micella formation thermodynamics and interracial characteristics of MPA.Some ther- modynamic parameters for constants of micelles formation(K_m).free energies of micelles formation(ΔG_m)and critical micella concentrations(CMC)were obtained.The inter- facial adsorption behaviour of D_2EHPA is opposite to that of MPA.The emulsification for single MPA and the mixed system was discussed.The synergistic effects were found in this mixed extraction system.It is proved that the process of the Fe^(3+) extraction for non-mixed extraction system is controlled by chemical reaction and the controlling reaction occurs at the interface.

Synergistic Extraction of Lanthanides by 1-Nitroso-2-Naphthol and Trioctylphosphine Oxide in Paraffin Wax

The paraffin wax was used as a diluent for 1-nitroso-2-naphthol(HA) and trioctylphosphine oxide(TOPO) in the extraction of lanthanides at 70℃. The composition of the extracted species was given as LnA_3(TOPO)_2 by means of the slope analysis. The variation of the synergistic extraction equilibrium constant(K_ sex) was investigated at 60～80℃, and the thermodynamic data were calculated. The dependence of separation factors on temperature was also studied.