Effect of pH on sorption for RE（Ⅲ） and sorption behaviors of Sm（Ⅲ） by D152 resin

The pH dependent sorption of rare earth ions （La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Y（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Tb（Ⅲ）, Dy（Ⅲ）, Ho（Ⅲ）, Er（Ⅲ）, Lu（Ⅲ）, and Yb（Ⅲ）） from HAC-NaAC buffer solution at 298 K by D152 resin containing -COOH function groups were presented. The sorption behaviors of D152 resin for Sm（Ⅲ） were discussed as an example. The effects of operational conditions such as pH, temperature, and contact time were studied. The statically saturated sorption capacity was 510 mg/g resin at pH 6.70 in HAc-NaAc medium at 298 K. The sorption behaviors obeyed the Freundlich isotherm. The capacity value for column study was obtained by graphical integration as 495 mg/g resin. Thomas model was applied to experimental data to predict the breakthrough curve and to determine the characteristic parameters of the column useful for process design.     

氨基膦酸树脂吸附铈的研究

研究了铈(Ⅲ)在氨基磷酸树脂上的吸附行为。试验结果在pH5.0时,静态饱和吸附容量为197mg/g干树脂;用2mol.L-1HCl洗脱,洗脱率为98.1%;表观速率常数k298=2.71×10-5s-1;等温吸附服从Freundlich经验式;吸附反应中的△Ho=50.0kJ.mol-1,△So=286J.mol-1.K-1,△Go=-35.1kJ.mol-1。树脂功能基与Ce3+的配比为2∶1;并用红外光谱探讨了树脂与铈的成键。     

Adsorption and desorption properties of D151 resin for Ce(III)

The present research is aimed at the development of D151 resin as an adsorbent that it can be used in the adsorption of Ce(III) ions. The adsorption and desorption behaviors of Ce(III) on D151 resin have been investigated by chemistry analysis. The influence of operational conditions such as contact time, initial concentration of Ce(III), initial pH of solution and temperature on the adsorption of Ce(III) had also been examined. The results show that the optimal adsorption condition of D151 for Ce(III) was achieved at pH=6.50 in HAc-NaAc medium. The maximum uptake capacity of Ce(III) was 392 mg/g resin at 298 K. The adsorption of Ce(III) followed both the Langmuir isotherm and Freundlich isotherm, and the correlation coefficients had been evaluated. Even kinetics on the adsorption of Ce(III) had been studied. The adsorption rate constant k_{298 K} valued was 1.3×10^?5 s^?1. The calculation data of thermodynamic parameters which ΔS⁰ value of 91.34 and ΔH⁰ value of 7.07 kJ/mol indicate the endothermic nature of the adsorption process. While, a decrease of Gibb's free energy (ΔG⁰) with increasing temperature indicated the spontaneous nature of the adsorption process. Finally, Ce(III) could be eluted by using 0.5 mol/L HCl solution and the elution percentage was as high as 100%. Adsorption mechanism was also proposed for the adsorption of Ce(III) ions onto D151 resin using infrared spectroscopy technique.     

Sorption behaviour and mechanism of ytterbium(III) on imino-diacetic acid resin

The sorption behaviour and mechanism of a novel chelate resin, imino-diacetic acid resin (IDAAR), for Yb(III) has been investigated in HAc–NaAc medium. The sorption of Yb(III) obeys the Freundlich isotherm. Optimum sorption for Yb(III) on IDAAR is at pH 5.13 and the statically saturated sorption capacity is 187 mg/g resin at 298 K. Yb(III) can be eluted using 1~2 mol L^− 1 HCl and the resin can be regenerated and reused without apparent decrease of sorption capacity. The apparent sorption rate constant is k₂₉₈ = 1.57 × 10^− 5 s^− 1; the apparent activation energy is 13.8 kJ mol^− 1 and the enthalpy change ΔH of IDAAR for Yb(III) is 29.8 kJ mol^− 1. The sorption mechanism of IDAAR for Yb(III) was examined by using chemical methods and IR spectrometry. The molar coordination ratio of the functional group of IDAAR to Yb(III) is 3:1 with the coordination compound formed between oxygen atoms in the functional group of IDAAR and Yb(III).     

Adsorption and desorption properties of D151 resin for Ce(Ⅲ)

The present research is aimed at the development of D151 resin as an adsorbent that it can be used in the adsorption of Ce(Ⅲ) ions.The adsorption and desorption behaviors of Ce(Ⅲ) on D151 resin have been investigated by chemistry analysis.The influence of operational conditions such as contact time,initial concentration of Ce(Ⅲ),initial pH of solution and temperature on the adsorption of Ce(Ⅲ) had also been examined.The results show that the optimal adsorption condition of D151 for Ce(Ⅲ) was achieved at pH=6.50 in HAc-NaAc medium.The maximum uptake capacity of Ce(Ⅲ) was 392 mg/g resin at 298 K.The adsorption of Ce(Ⅲ) followed both the Langmuir isotherm and Freundlich isotherm,and the correlation coefficients had been evaluated.Even kinetics on the adsorption of Ce(Ⅲ) had been studied.The adsorption rate constant k298 K valued was 1.3×10-5 s-1.The calculation data of thermodynamic parameters which ΔS0 value of 91.34 and ΔH0 value of 7.07 kJ/mol indicate the endothermic nature of the adsorption process.While,a decrease of Gibb’s free energy(ΔG0) with increasing temperature indicated the spontaneous nature of the adsorption process.Finally,Ce(Ⅲ) could be eluted by using 0.5 mol/L HCl solution and the elution percentage was as high as 100%.Adsorption mechanism was also proposed for the adsorption of Ce(Ⅲ) ions onto D151 resin using infrared spectroscopy technique.     

Adsorption behavior of ytterbium (Ⅲ) on gel-type weak acid resin

The adsorption and desorption behaviors of Yb(Ⅲ) on gel-type weak acid resin (110) were investigated. The influence of operational conditions such as contact time,initial concentration of Yb(Ⅲ),initial pH of solution and temperature on the adsorption of Yb(Ⅲ) were also examined. The results showed that the optimal adsorption condition of 110 resin for Yb(Ⅲ) was achieved at pH=5.5 in HAc-NaAc medium. The maximum uptake capacity of Yb(Ⅲ) was 265.8 mg/g at 298 K. Yb(Ⅲ) could be eluted by using 3.0 mol/L HCl solution and the 110 resin could be regenerated and reused. The adsorption of Yb(Ⅲ) followed the Langmuir isotherm,and the correlation coefficients were evaluated. Various thermodynamic parameters such as standard enthalpy change (△H),standard entropy change (△S) and standard free energy change (△G) were evaluated. The adsorption of Yb(III) on the 110 resin was found to be endothermic in nature. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristics parameters of the column useful for process design. And the resin sample both before and after adsorption was described by IR spectroscopy.     

Solid-liquid extraction of Gd(Ⅲ) and separphosphoric acid solutions using Tulsion C

Solid-liquid extraction of gadolinium was investigated from phosphoric acid medium using commercial amino phosphonic acid resin, Tulsion CH-93. The experimental conditions studied included equilibration time, acid concentration, mass of the resin, metal concentra-tion, loading and elution. The percent extraction of Gd(Ⅲ) was studied as a function of phosphoric acid (0.05-3 mol/L) using Tulsion CH-93 resin. The corresponding lgD vs. equilibrium pH plot gave straight line with a slope of 1.8. The percent extraction decreased with acid con-centration increasing, conforming ion exchange mechanism. Under observed experimental conditions the loading capacity of Tulsion CH-93 for gadolinium was 10.6 mg/g. Among several eluants screened, the quantitative elution of Gd(Ⅲ) from loaded Tulsion CH-93 was obtained with ammonium oxalate (0.15 mol/L). The extraction behavior of commonly associated metals with gadolinium was studied as a function of phosphoric acid concentration. Tulsion CH-93 resin showed selective extraction towards heavy rare earths (Lu and Yb) which could be sepa-rated from other rare earths at 3 mol/L H3PO4, similar to wet phosphoric acid (3-5 mol/L). On the other hand Gd(Ⅲ) and other rare earths were studied with chelating resin Tulsion CH-90. Light rare earths were highly extracted and these could be separated from heavy rare earths and Gd.)     

Adsorption behavior of Cd(II) from aqueous solutions onto gel-type weak acid resin

The adsorption and desorption behaviors of Cd(II) on gel-type weak acid resin (GTWAR) have been investigated. The influence of operational conditions such as contact time, initial concentration of Cd(II), initial pH of solution and temperature on the adsorption of Cd(II) has also been examined. The results show that the optimal adsorption condition of GTWAR for Cd(II) is achieved at pH = 5.95 in HAc–NaAc medium. The maximum uptake capacity of Cd(II) is 282 mg/g GTWAR at 298 K. The adsorption of Cd(II) follows the Langmuir isotherm and Freundlich isotherm, and the correlation coefficients have been evaluated. Even kinetics on the adsorption of Cd(II) has been studied. The apparent activation energy E_a and adsorption rate constant k₂₉₈ values are 2.95 kJ/mol and 3.02 × 10^− 5 s^− 1, respectively. The calculation data of thermodynamic parameters which ΔS value of 110 J/(mol K) and ΔH value of 13.1 kJ/mol indicate the endothermic nature of the adsorption process. Whilst, a decrease of Gibb's free energy (ΔG) with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Cd(II) can be eluted by using 0.5 mol/L HCl solution and the gel-type weak acid resin can be regenerated and reused. The sample was described by IR spectroscopy and scanning electron micrographs (SEM).     

Evaluation of D113 cation exchange resin for the removal of Eu(III) from aqueous solution

Batch adsorption experiments were conducted for the adsorption of Eu(III) ions from aqueous solution by D113 resin. The results indicated that D113 resin could adsorb Eu(III) ion effectively from aqueous solution. The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.50 to 7.00 and the optimal adsorption condition was in HAc-NaAc medium with pH value of 6.50. The maximum uptake capacity of Eu(III) ions was 290.9 mg/g D113 at 298 K, at an initial pH value of 6.50. The overall adsorption process was best described by Lagergren-first-order kinetics. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The thermodynamic parameters such as free energy (?G) which were all negative, indicated that the adsorption of Eu(III) ions onto D113 resin was spontaneous and the positive value of enthalpy (?H) showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. Furthermore, Eu(III) could be eluted by using 3.0 mol/L HCl solution and the D113 resin could be regenerated and reused.     

The kinetics of antimony(III) sorption on inorganic ion exchangers for its removal from copper refining electrolytes

The effect of varying linear flow velocity and initial antimony concentration in copper electrolytes on the sorption of antimony(III) using β-stannic acid at 18 and 65°C is reported. The kinetics of sorption appear to be controlled both by internal diffusion and the rate of chemical reaction. The apparent order of reaction with respect to Sb(III) is 1. The rate constant increased with both increasing flow rate of the liquid and antimony concentration. The apparent activation energy was 32.8 kJ/mol.     

氯型季铵树脂对钨酸根吸附的热力学研究

针对钨离子交换工艺热力学参数缺乏的问题,测定了不同温度下氯型季铵树脂吸附钨酸根的平衡数据,由此计算出吸附过程的热力学参数.结果表明,吸附平衡数据符合Langmiur等温吸附方程;在求算Langmiur模型常数项时,非线性拟合方法对实验数据的拟合精度优于线性拟合的方法;氯型季铵树脂对钨酸根的吸附是吸热过程,ΔH为13.505 kJ /mol,ΔS为0.098 kJ /（mol·K）,ΔG（298）为-15.833 kJ /mol;并且,ΔG随着温度升高而变小,说明温度升高有利于获得更大的钨吸附容量,热力学分析与实验结果一致.      

CL-P204萃淋树脂对溶液中钒的吸附性能研究

探究CL-P204萃淋树脂对溶液中V(Ⅳ)的吸附效果。考察溶液pH、反应时间、初始浓度、温度对钒吸附容量的影响,并对吸附过程进行了动力学和热力学分析。结果表明,CL-P204萃淋树脂在298K、pH=1.6的条件下,吸附8h即可达到平衡,对V(Ⅳ)的最大吸附容量为34.2mg/g。树脂循环使用4次后对钒依然有良好的吸附效果。CL-P204萃淋树脂对钒的吸附过程符合准二级动力学方程和Langmuir等温吸附方程,是吸热熵增加的自发反应。     

Adsorption of erbium(III) on D113-III resin from aqueous solutions: batch and column studies

The adsorption and desorption behaviors of Er(III) ion on D113-III resin were investigated. Batch adsorption studies were carried out with various Er(III) ion concentrations, pH, contact time and temperature, indicating that D113-III resin could adsorb Er(III) ion effectively from aqueous solution. The loading of Er(III) ion onto D113-III resin increased with increasing the initial concentration. The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.45 to 6.75. In the batch system, the D113-III resin exhibited the highest Er(III) ion uptake as 250 mg/g at 298 K, at an initial pH value of 6.04, calculated from the Langmuir isotherm model. The adsorption kinetics was in agreement with Lagergren-first-order kinetics among the Lagergren-first-order model, pseudo-second-order model, liquid film diffusion model and intraparticle diffusion model. The adsorption data gave good fits with Langmuir isotherms. The thermodynamic parameters such as ΔG, which were all negative, indicated that the adsorption of Er(III) ion onto D113-III resin was spontaneous and the positive value of ΔH showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. Er(III) ion could be eluted by using the 4.0 mol/L HCl solution. The characterization of both before and after adsorption of Er(III) ion on D113-III resin was undertaken with IR spectroscopic technique. Moreover, the surface characterization of D113-III resin was described by scanning electron micrographs (SEM).     

Study on the diffusion kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregnated resin

Kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregn ated resin was studied. The influences of temperature,concentration,granularit y of resin on the exchange degree were investigated by the limited bath method. The result showed that the controlling factor of RE3+/H+ diffusion on Cyanex272-P507 extraction resin was particles diffusion. The process of diffuse kinetics f itted well with the expression developed by Body model. The apparent activation energy was determined as 23.20 kJ/mol. The reaction order was 0.452. In addition,the constant of particles diffusion(D0) was 1.352×10-8 m2/S and the entropy of diffusion was-47.055 J/(mol·K).     

Physico-chemical properties of 3-methoxy-2-nitrobenzoates of some rare earth elements（Ⅲ）

The complexes of 3-methoxy-2-nitrobenzoates of Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Er(III) and Tm(III) with the formula: Ln(C8H6NO5)3·2H2O, where Ln=lanthanides(III), were synthesized and characterized by elemental analysis, Forier transform irtrared (FTIR) spectroscopy, magnetic and thermogravimetric studies and also by X-ray diffraction (XRD) measurements. The complexes had col- ours typical for Ln(III) ions. The carboxylate groups bound as bidentate chelating. On heating to 1173 K in air they decomposed in the same way, at first, dehydrated in one step to anhydrous salts, and then decomposed to the oxides of respective metals with intermediate formation of the oxycarbonates. The enthalpy values of the dehydration process changed from 133.72 to 44.50 kJ/mol. Their solubility in water at 293 K was of the order of 10-4 mol/dm3. The magnetic moments of analysed complexes were determined by Gouy’s method in the range of 76-303 K.     

Sorption of Rhenium from Sulfuric Acid Solutions with Trialkylamine-Containing Impregnates

The sorption of rhenium (VII) from sulfuric acid solutions with impregnates based on macroporous polymeric carriers (copolymers of styrene with divinylbenzene, a weakly acidic cation-exchange resin), which contain technical trialkylamine (TAA), is investigated in batch conditions. Equilibrium and kinetic characteristics of sorption of rhenium with the K-TAA impregnate based on macroporous cationite having the best capacitive characteristics with respect to rhenium are found. The maximal distribution coefficient of rhenium in the K-TAA impregnate is observed during sorption from solutions with pH 2. The sorption isotherm of rhenium is described by the Langmuir equation with constant K = 29 ± 2 mL/g. Integrated kinetic curves of sorption are found by the method of a limited solution volume at various temperatures and effective diffusion coefficients of rhenium in an impregnate, which are equal to 3.8 × 10^–11 (295 K) and 1.3 × 10^–10 (308 K) m²/s, are calculated allowing to the half-transformation time. Processing the kinetic data by linearization according to equations of models of the pseudo-first, pseudo-second, internal diffusion, and Elovich showed that kinetic curves are described with the highest degree of correlation by pseudo-second-order equations with rate constants 0.00056 (295 K) and 0.00059 (308 K) g mg^–1 min^–1. The apparent activation energy of sorption of rhenium of 39 ± 2 kJ/mol is calculated according to the Arrhenius equation. The K-TAA impregnate is approved for the sorption of rhenium from the eluate formed during the desorption of rhenium from the weakly basic anion-exchange resin (Purolite A170) preliminarily saturated with rhenium from a productive leaching solution of processing products of rhenium-containing off-balance copper-sulfide ores with a complex composition.     

Sorption recovery of rhodium(III) from multicomponent chloride solutions in the presence of tin(II) chloride

The influence of tin (II) chloride additives on sorption of Rh(III) on the Purolite S920 ion exchange resin with isothiouronium groups, the Purolite S985 weak base anion exchange resin, and the Purolite A500 strong base anion exchange resin is investigated. It is established that the introduction of SnCl₂ leads to a substantial increase in selectivity of all tested ion exchange resins to Rh(III) and in the sorption rate of Rh(III) on S985 and S920 ion exchange resins. The optimal dosage of SnCl₂ (0.01 mol/L) at which the distribution coefficients of Rh(III) during sorption for all tested ion exchange resins reach maximal values is determined. It is shown that almost quantitative recovery of Rh(III) is attained when passing the multicomponent chloride solution of the composition (g/L) 0.2 Rh(III), 72.9 HCl, 53.5 NH₄Cl, 2.7 Al(III), 1.23 Fe(III) and 5.9 Sn(IV) with the SnCl₂ additive through the Purolite S920 ion exchange resin with isothiouronium groups. Desorption of Rh(III) from the Purolite S920 saturated ionite with the acidified thiourea solution is incomplete, no greater than 60%.     

高磷鲕状赤铁矿酸浸脱磷动力学

在HSC6.0计算软件热力学分析的基础上,采用正交实验确定了高磷鲕状赤铁矿酸浸脱磷保铁的最佳工艺,并以最佳工艺为基础进行了酸浸过程中脱磷和铁损反应的动力学研究。热力学分析表明H_2SO_4为最佳酸浸用酸。正交实验得出最佳酸浸条件为:H+浓度为0.5mol/L的H_2SO_4溶液、酸浸时间40min、温度298K、液固比200mL∶14g、搅拌速度100r/min。在该条件下,脱磷率可达98.89%,铁损率仅为0.51%。通过SEM-EDS对酸浸前后高磷鮞状赤铁块矿试样分析表征得出:经H_2SO_4浸出后,磷灰石基本完全溶解,含铁矿相未发生明显反应。动力学分析显示:优化条件下,酸浸脱磷反应在298~328K内符合收缩未反应核模型,浸出过程主要受内扩散控制,表观活化能为11.24kJ/mol;铁损反应在298~328K内遵循收缩未反应核模型,浸出过程主要受化学反应控制,表观活化能为42.24kJ/mol。     

Enhanced adsorption behavior of Nd(III) onto D113-III resin from aqueous solution

An enhanced adsorption and desorption procedure of Nd(III) onto D113-III resin were prepared with various chemical methods.Batch studies were carried out with various pH,contact time,temperature and initial concentrations,and then column studies were conducted.The results showed that the optimal adsorption condition was at pH value of 6.90.The process was fast initially and arrived equilibriumwithin 60 h.The resin exhibited a high Nd(III) uptake as 232.56 mg/g at 298 K.The adsorption data fitted well with p...     

Kinetics of leaching of lead sulfate in sodium chloride solutions

A powder dissolution method is used to study the kinetics of leaching of lead sulfate from a lead cake in the temperature range 298–353 K and the concentration range 50–270 g/l of a sodium chloride solution. The results obtained are used to calculate the apparent activation energy (E _a = 12.41 kJ/mol); its value indicates that the process of leaching of lead sulfate from a lead cake occurs in a diffusion zone. This process is shown to be described by a first-order kinetic equation.