Removal of tungsten and vanadium from molybdate solutions using ion exchange resin

The removal of tungsten (W) and vanadium (V) from molybdate solutions was studied using the poly hydroxyl chelating resin D403 in batch and column experiments. The batch experiments indicated that tungsten and vanadium could be preferentially adsorbed by the D403 resin for 4 h in molybdate solution at a pH of approximately 9.25. Separation factors, α_Mo^V and α_Mo^W, were above 45 and 18, respectively, when the molar ratios of Mo/V and Mo/W in the solution exceeded 40. Elution tests illustrated that vanadium and tungsten could be easily eluted from the resin with 1 mol/L sodium hydroxide solution in only 1 h. To further explore the sorption mechanism of the resin, the experimental equilibrium isotherm data of the three metals fitted well with the Freundlich model. The column experiments confirmed the adaptability of the D403 resin in the production of sodium molybdate with a removal rate of tungsten surpassing 90% and that of vanadium of 99.4%.     

离子液体Cyphos IL104的溶剂浸渍树脂的制备及其在铬(VI)回收中的应用(英文)

采用XAD-7树脂浸渍离子液体二(2,4,4三甲基戊基)亚膦酸三己基十四烷基烷基鏻(Cyphos IL104)。研究该种溶剂浸渍树脂(SIR)的制备过程及其在Cr(VI)分离中的应用,并对树脂的表面形貌和热稳定性进行表征。研究平衡时间和初始pH值对Cr(VI)吸附的影响,讨论溶剂浸渍树脂的吸附等温线、吸附和解吸附过程以及浸渍树脂的选择性。结果表明,萃取剂Cyphos IL104浸入了树脂的内部孔道中,溶剂浸渍树脂吸附Cr(VI)的最佳pH范围为0-2。当CyphosIL104作为解吸附溶液时,Cr(VI)可以从树脂上有效地脱附。     

Selectivity recovery of molybdenum(VI) from rhenium(VII) by amine-modified persimmon waste

Amine functional group was grafted to obtain modified persimmon waste gel(NH_2–CPT) with the focus of development of selective recovery of molybdenum from rhenium. The adsorption behavior of the NH_2–CPT gel for various metal ions at varying hydrochloric acid concentrations was studied. It is found that the NH_2–CPT exhibits high affinity for Mo(VI) and no affinity for Re(VII), Cu(II),Fe(III), Mn(VII), and Zn(II) under the operating conditions. The maximum adsorption capacity for Mo(VI) is 172 mgág-1, and the adsorption behavior obeys the Langmuir model. Owing to Mo(VI) as poly-anions, the adsorption mechanism of molybdenum anions could be explained as the anion exchange reactions at weak acid concentration, while neutral molecules could be explained as the complexation reactions at strong acid concentration,respectively. In addition, its excellent adsorption characteristics for Mo(VI) are confirmed by separation of Mo(VI)from Mo to Re containing industrial effluent.     

Existing form of Mo(Ⅵ) in acidic sulfate solution

The existing form of molybdenum in acidic sulfate solution was studied by means of ion exchange,infrared(IR) spectra and X-ray photoelectron spectroscopy(XPS).The results indicate that the anionic molybdenum species are predominant in acidic sulfate solution,and Mo(VI) can combine with sulfate radical to form heteropoly acid anions[Mo_2O_5(SO_4)_2]~(2-) and[MoO_2(HSO_4)_4]~(2-).With the decrease in solution pH from 1.92 to 0.06,the existing form of Mo(VI) changes from Mo_7O_(21)(OH)_3~(3-) to[Mo_2O_5(SO_4)_2]~(2-) and then becomes[MoO_2(HSO_4)_4]~(2-),which results in the decrease in the resin adsorption capacity for molybdenum.     

Recovery of Mo from Ni-Mo ore leach solution with carrier co-precipitation method

In this paper, “nascent” Fe(OH)₃ as carrier precipitation and NaHCO₃ as buffer agent were used to extract molybdenum from the complex Ni-Mo ore leach solution. The effects of different variables on the molybdenum extraction, such as the dosage of FeCl₃ and NaHCO₃ and the reaction temperature and time, were studied. The results showed that over 99% of molybdenum were extracted in 2 h at 25 ± 1 °C under the conditions of mole ratio of Fe³⁺/Mo 2.2-2.5 and mass ratio of NaHCO₃/Mo 0.7-1.5. About 92% of Mo in the Fe(OH)₃ precipitation can be leached by NH₃⋅H₂O to prepare the ammonium molybdate solution with about 100 g/L Mo. After treating with NH₃⋅H₂O, the Fe(OH)₃ precipitation was dissolved with HCl to obtain the FeCl₃ solution (FeCl₃ 500 g/L) which can be reused for the next round of experiments.     

V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系热力学研究与钒铁分离方法理论

针对酸浸液钒铁分离的难题,绘制298 K时V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系中存在的各种离子随pH以及浓度变化的热力学平衡图,全面分析钒、铁物种随pH和钒、铁、硫浓度的变化规律,在此基础上提出相应的钒铁分离方法并进行理论分析。结果表明:强酸条件(?1相似文献   

从沉钨钼后液中制备高纯铼酸铵

利用沉钨钼后液首先经氯化钾沉淀反应得到铼酸钾,其次采用离子交换法将铼酸钾溶液转为高铼酸溶液,最后经氨水中和-浓缩结晶-重结晶得到高纯铼酸铵。结果表明:向沉钨钼后液中加入KCl固体再浓缩析出KReO₄白色晶体,其主要杂质Na、Ca、Fe、Cl含量均小于1.00%,特别是W、Mo含量均小于0.10%,且Re结晶率可达94.92%～98.38%。采用动态法脱K,选用C160(H⁺型)树脂,当KReO₄溶液pH为中性,料液流速控制在2BVs·h^-1时,C160树脂对K⁺穿透容量和饱和容量分别为117.87和128.39g·L^-1,且树脂利用率达到91.81%;所得纯HReO₄溶液中K、Na、Ca、Fe、W、Mo、Mg浓度均降至0.50 mg·L^-1以下。通过添加优级纯氨水中和HReO₄溶液,控制终点pH为7～8,再经浓缩结晶+1次重结晶,所得铼酸铵纯度达到99.99%以上,其SEM形貌为树枝状。     

Kinetic modeling of adsorption of vanadium and iron from acid solution through ion exchange resins

This study assessed the adsorption process and the reaction kinetics involved in the selective recovery of vanadium from an acid solution containing iron as an impurity. Four commercial resins were studied: Lewatit® MonoPlus TP 209 XL, Lewatit® TP 207, Dowex? M4195 (chelating resin) and Lewatit® MonoPlus S 200 H (strong cationic exchange resin). To investigate the effect of time on the adsorption process, batch experiments were carried out using the following initial conditions: pH 2.0, 298 K, and a proportion of 1 g of resin to 50 mL of solution. The variation of pH over time was analyzed. Chelating resin released less H⁺ ions as the adsorption occurred, resulting in a lower drop of pH when compared to S 200 H resin. Ion adsorption by the resins was also evaluated through FT-IR and SEM?EDS before and after the experiments. Among the evaluated kinetic models (pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models), the pseudo-second order model best fits the experimental data of the adsorption of vanadium and iron by all of the four resins. M4195 resin showed the highest recovery of vanadium and the lowest adsorption of iron. Kinetic data, which are fundamental to industrial processes applications, are provided.     

Recovery of V<Subscript>2</Subscript>O<Subscript>5</Subscript> from Bayer liquor by ion exchange

A new technology was developed to recover V2O5 from Bayer spent liquor by ion exchange.The experimental results show that in the conditions of 105°C and 0.20-0.25 mass ratios between CaO in lime and Al2O3 in spent liquor, the precipitation rate of vanadium in Bayer liquor is more than 85%.The vanadium-bearing precipitation is leached by NaHCO3 solution.The leaching rate of vanadium can reach 85% in the conditions of 95°C, 40 g·L-1 of NaHCO3 concentration, and ventilating of CO2.The 201 × 7 type of resin has...     

An electrochemical study on the influence of sodium molybdate on electrodeposition process and phase composition of ternary Zn–Ni–Mo alloy coatings

Ternary Zn–Ni–Mo alloy coatings were deposited from a citrate-sulphate bath at pH 5.7 containing different amounts of sodium molybdate. The content of molybdenum in the coatings (from 0.3 to 5.2?at.-%) can be easily controlled by increasing sodium molybdate concentration in the plating bath from 0.0025 to 0.05?mol?dm^??3, which results also in deposition of smoother deposits. An increase in molybdate concentration leads to the shift of reduction potentials towards more negative values and to the decrease in current efficiency of deposition process. XRD analyses and anodic linear sweep voltammetry (ALSV) measurements demonstrated that at least two phases are formed in the Zn–Ni–Mo alloy: a hexagonal zinc phase or solid solution of nickel in zinc and Ni₅Zn₂₁ intermetallic compound. Furthermore, the XRD analyses revealed a third phase, which could be assigned to the oxidised species of molybdenum or other alloying metals.     

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.     

Preparation of single-phase ammonium dimolybdate by combination process

A novel method for the preparation of single-phase ammonium dimolybdate with industrial ammonium molybdate was studied.Various influential factors were evaluated in the paper,including reaction temperature,reaction time,initial molybdenum concentration,initial NH3/Mo molar ratio,and stirring speed.Under the optimum experimental conditions,the crystallization rate of product is 85.23％.The X-ray diffraction (XRD) analysis and chemical analysis show that the product is single-phase ammonium dimolybdate,and no impurity phases exist.The scanning electronic microscope (SEM) image reveals uniform particle size,good particle dispersion,and no agglomeration between particles.Meanwhile,the final pH value of acidification was investigated.The total molybdenum recovery can reach up to 99.40％,and the main phases of acidification product are the same as those of raw material with the final pH value of 1.5.This determines that the acidification product can be used as a raw material to produce single-phase ammonium dimolybdate.     

纳米TiO_2对钼(Ⅵ)的吸附性能

研究纳米TiO_2对Mo(VI)的吸附过程,考察溶液的pH值、时间、温度等因素对吸附的影响.结果表明:在pH 1～8范围内,纳米TiO_2对Mo(VI)的吸附率均超过99%,吸附于纳米TiO_2上的Mo(VI)可用2.0 mL的0.1 mol/L NaOH溶液定量洗脱;该吸附过程符合准二级反应动力学模型,其反应的表观活化能为22.7 kJ/mol,粒子内部扩散过程是其吸附控制步骤,但液相边界层向粒子表面的扩散过程不能忽略;吸附行为服从Langmuir和D-R等温模型.在室温下,纳米TiO_2对Mo(VI)的饱和吸附容量为12.74 mg/g,平均吸附能为17.36 kJ/mol;吸附反应焓变和熵变均为正值,自由能变为负值,说明该吸附过程为自发的吸热过程.     

离子交换树脂法吸附、解吸钯工艺研究

用9335型阴离子交换树脂吸附经王水溶解的含钯物料,可以选择性吸附钯,铜、镍等杂质不被吸附。用8%氨水、40 g/L氯化铵解吸,98%以上的钯被解吸。吸附操作简单,解吸后的树脂可重复使用。     

8-羟基喹哪啶螯合树脂吸附钯(Ⅱ)的性能研究

用静态法研究了8-羟基喹哪啶螯合树脂在酸性溶液中吸附和解吸Pd(II)的性能，分析了吸附等温线和吸附动力学过程。结果表明，在0.6 mol/L HCl的介质中，树脂对Pd(II)的饱和吸附量为99.46 mg/g，吸附率为94.7%，解吸率达到95.6%；吸附过程符合Langmuir和Freundlich等温吸附模型，准二级动力学Lagergren方程更适合描述此吸附过程。     

The corrosion of vanadium and vanadium-base binary alloys in oxygen-saturated liquid sodium

The corrosion of vanadium and vanadium-base binary alloys, VCr, VAl, VFe, and VMo, in oxygen-saturated sodium was studied. A ternary oxide containing sodium and vanadium was detected in the corrosion product formed on vanadium. The formation rate of the corrosion product followed a linear rate law above 450°C. From examination of alloying additions on the corrosion of vanadium, molybdenum was found to improve considerably the corrosion resistance of vanadium to the liquid sodium. In particular a V50wt%Mo alloy was observed to corrode only very slightly in sodium. The corrosion resistance of the VMo alloys was considered to be caused by molybdenum enrichment of the surface layers as the corrosion proceeded.     

从铜冶炼烟气酸洗液中分离富集铼

铜冶炼烟气酸洗液经D296阴离子交换树脂吸附后,再依次采用氨水解吸Sb,NaOH和酒石酸混合溶液解吸Bi,NH₄SCN溶液解吸Re,实现Re/Sb/Bi的分步解吸并获得铼富集液。结果表明：酸洗液电位对Re、Sb、Bi吸附率没有明显影响,适宜的酸洗液H₂SO₄浓度为43.81 g·L^-1,Re、Sb、Bi吸附率分别为100%、6.55%和89.05%;D296树脂吸附Re的穿透容量和饱和容量分别为1.308和1.773 g·L^-1,且树脂利用率为73.77%;先采用12.5%氨水解吸Sb,16%NaOH+140 g·L^-1酒石酸混合溶液解吸Bi,通过添加酒石酸可有效抑制Bi水解,再采用10%NH₄SCN溶液解吸Re,得到铼富集液,其Cu、As、Sb、Bi浓度均降至1 mg·L^-1以下,且使酸洗液中Re富集了4倍。     

Vanadium recovery from clay vanadium mineral using an acid leaching method

A technique including direct acid leaching,vanadium precipitation with alkaline,sodium hydroxide releaching,impurity removing by adjusting pH value,precipitation vanadium with ammonium chloride,and vanadium pentoxide by roasting steps was proposed according to the characteristic of Xichuan clay vanadium mineral.The factors influencing leaching vanadium such as temperature and the concentration of sulfuric acid were investigated and optimized.The experimental results indicate that the extract ratios of V2O5 can reach 94% and 92% at a sodium chlorate ratio of 3% and a manganese dioxide ratio of 3%,respectively.A completely chemical precipitation method was adopted to decontaminate and enrich the vanadium in the acid leaching solution.The X-ray diffraction (XRD) pattern and the purity analysis of vanadium pentoxide indicate that the purity of final vanadium pentoxide can reach 99% and meet the standard specifications.The total recovery can reach about 75%.The technique has the characteristics of simplicity,less investlnent,and more environment safety as compared with the traditional salt roasting method.     

新型硫脲螯合树脂对金(Ⅲ)吸附性能的研究

用静态法较系统地研究了新型硫脲树脂从酸性含金氯化溶液中吸附金及其解吸金的性能,结果表明,在实验条件下,新树脂在含有Au3+、Cu2+、Ni2+和Fe3+等离子的混合体系中,对Au3+有良好的吸附容量和选择性,并能定量地解吸树脂所吸附的Au3+。在适宜条件下,该树脂对金的吸附率和解吸率均达到98%以上。     

Adsorption of XSD-296 resin for Cr（Ⅵ）

The adsorption properties of XSD-296 for Cr（Ⅵ） were studied by using chemical analysis and infrared spectrometry. Experimental results show that XSD-296 resin has a good adsorption ability for Cr（Ⅵ） at pH=2.6 in the HAc-NaAc medium. The statically saturated adsorption capacity is 235 mg/g resin. The apparent activation energy of adsorption reaction, Ea, is 16.73 kJ/mol, and the thermodynamic parameters are △H=11.62 kJ/mol, △G298 K=-4.13 kJ/mol. The adsorption behavior of resin for Cr（Ⅵ） is in accordance with Freundlich adsorption isotherm. Cr（Ⅵ ） adsorbed on resin can be eluted by 5%NaCl-5%NaOH or 5%NH4Cl-5%NH3-H2O quantitatively. Infrared spectra and adsorption mechanism show that the functional group of resin coordinates with Cr（Ⅵ） to form co-ordination compound. The coordination molar ratio of the functional group of resin to Cr（Ⅵ） is 1：1.