采用混合离子交换树脂提取钨酸根

本项目利用分光光度计和电感耦合等离子体-质谱联用仪(ICP-MS)测定钨酸根浓度,采用201x7、201x W和201x4阴离子交换树脂吸附钨矿提取液中的钨酸根离子,探究阴离子树脂混合比例对钨酸根离子的离子交换量,以及提取液中共存的杂质离子锡酸根、钼酸根对钨酸根吸附量和选择性的影响。结果表明:201x4树脂对钨酸根离子的吸附量最大,但选择性差;杂质离子对树脂吸附量和选择性影响较大。动态实验表明杂质离子可使钨酸根解吸附曲线后移,钨酸根吸附量减少。     

Cyanide Recovery from Gold Extraction Process Waste Effluents by Ion Exchange II. Modelling of the Fixed Bed Operation

Abstract

An ion exchange operation in a fixed bed column is tested as a method to recover copper cyanide complexes from gold extraction process waste effluents. With this aim in mind, load and elution breakthrough curves are obtained using the anionic resin Lewatit MP500. A good performance of the resin in the load stage can be deduced from the breakthrough curves obtained in all the assays at two different pHs (12, 8.5). After load step operation, column elution was carried out using NaSCN 1.25 M as eluent. A good elution peak is obtained in all cases, indicating a good performance of the resin and the eluent in this stage. With the aim of testing the design of the industrial operation, a phenomenological model is tested by fitting experimental data to theoretical equations. The model used for the simulation of both steps incorporates axial dispersion, ion exchange equilibrium, and diffusion inside particles described by the linear driving force approximation, as well as taking into account the fact that the resistance to mass transfer controls the kinetics of the ion exchange process. The models are able to simulate the experimental load and elution results reasonably well.     

Recovery of 1,4‐Dimethyl Piperazine from Aqueous Solutions Using Polymeric Adsorbent and Ion‐Exchange Resins

Abstract

Strong and weakly acidic ion exchange resins and polymeric adsorbents are used for recovery of 1,4‐dimethyl piperazine (DMP) from aqueous solutions. Sorption of the amine in undissociated form is the primary mechanism of uptake of DMP on the ion‐exchange resins. Equilibrium adsorption data for DMP on the resins, at various temperatures, are fitted in Langmuir adsorption isotherm. Kinetic studies show that intraparticle diffusional resistance controls the sorption of DMP into the resin matrix. A mathematical model based on intraparticle diffusion and external mass transfer is used for simulating breakthrough profiles and compared with the experimental results for a fixed bed of weakly acidic Indion‐652 resin. The DMP loaded bed of the resin was effectively regenerated with methanol.     

New Infrared Study of Water in Ion Exchange Resins

The water present in cation and anion exchange resins for a series of counter-ions was examined spectroscopically using the 1.9 μ water band. The spectrum of the water in the resins dried to constant weight was characteristic for the counter-ion present. The changes in the wavelength of the maximum absorbance was compared to the behaviour of the spectrum of ions in solution. The spectra of these resins were also related to the hydration numbers of various ions.     

混合离子交换树脂除盐的性能研究

研究了强酸型离子交换树脂D072和强碱型离子交换树脂D201混合吸附杂离子的性能。D072和D201的质量比为1∶2,考察其30℃时的吸附特性,结果表明,混合树脂符合兰格缪尔吸附模型,等温吸附平衡方程为q=7.55c/(0.97+c) (R2=0.9971)。此外,考察了树脂固定床的操作性能。进料流速与初始进料浓度对树脂固定床的穿透曲线影响显著,当液相初始进料浓度为800 mg/L、进料速度为3 min/L时,穿透时间为83 min,该操作条件大幅提高了离子交换树脂的吸附效率。     

Evaluation of Elution Parameters for Cesium Ion Exchange Resins

Abstract

Cesium ion exchange is one of the planned processes for treating and disposing of waste at the U.S. Department of Energy Hanford Site. Radioactive supernatant liquids from the waste tanks will undergo ultrafiltration, followed by cesium ion exchange using a regenerable organic ion exchange resin. Two resins, SuperLig^®644 and a resorcinol‐formaldehyde resin, are being evaluated for cesium removal and cesium elution characteristics. The main purpose of this study is to optimize the cesium elution to provide a resin that, after undergoing elution, would meet the U.S. Department of Energy/Office of River Protection Project‐Waste Treatment Plant processing and resin disposal criteria. Columns of each resin type were loaded to greater or equal to 90% breakthrough with a Hanford waste stimulant and eluted with nitric acid. The temperature, flow rate, and nitric acid concentration were varied to determine the optimal elution conditions. Temperature and eluant flow rate were the most important elution parameters. As would be predicted based upon kinetic consideration alone, decreasing the eluant flow rate and increasing the temperature provided the optimal elution conditions. Varying the nitric acid concentration did not have a significant effect on the elution completion; however, elutions performed using both high acid concentration (1 M) and elevated temperature (45°C) resulted in resin degradation, causing gas generation and resin bed disruption.     

二次悬浮聚合树脂的合成及应用技术探讨

对苯乙烯-二乙烯苯悬浮共聚制离子交换树脂珠体进行研究,探讨了各种因素对二次悬浮聚合离子交换树脂珠体粒径的影响及利用二次悬浮聚合白球合成的阴阳离子交换树脂在水处理应用中对出水水质的影响。     

离子交换树脂运行中存在的问题及应对措施

现阶段,随着我国社会和经济的快速发展,我国电力行业也在不断进步,发电机组单机容量逐渐向着超临界、高参数、大容量反向发展,机组性能得到大幅度提升,这也就提升了对电厂除盐水水质的要求。离子交换树脂是电厂应用较多的除盐应用,但是,离子交换树脂子在实际运行过程中还存在很多问题。因此,主要分析,离子交换树脂子在运行中存在的问题,进而提出必要的应对措施,并为同行业研究提供必要依据。     

离子交换树脂在1,3-丙二醇生产中的应用

通过静态吸附和动态脱盐实验,研究了离子交换树脂在1,3-丙二醇脱盐中的应用情况。通过静态吸附实验表明,001×7型树脂吸附能力最大,最佳吸附温度为40℃;通过动态脱盐实验表明,001×7型树脂动态吸附量为1740mg/g。通过树脂的成本、处理能力分析,表明001×7型树脂完全可以应用于生产。     

1，3-丙二醇发酵液脱盐用离子交换树脂的筛选

研究了用离子交换树脂处理1,3-丙二醇发酵液,选用6种阳离子交换树脂和3种阴离子交换树脂,以交换容量、电导率和再生时间为指标,考察了树脂的脱盐效果。结果表明：阳离子交换树脂中的D001-cc对1,3-丙二醇发酵液的处理效果最好,150mL树脂的平均交换容量达到240mL,电导率能降到2250gS／cm,再生时间7h;3种阴离子交换树脂中,D301R的去盐效果最好。     

Effect of Microwave Radiation on the Synthesis of Ion Exchange Resins: A Comparative Study

A series of new ion exchange resins was synthesized in a microwave radiation field by modification of chloromethylated styrene/divinylbenzene (S/DVB) and vinylbenzylchloride/divinylbenzene (VBC/DVB) copolymers using amines. The modification processes have been executed simultaneously using the microwave-assisted method and the most efficient, conventional one. The greatest total sorption capacities for noble metals were achieved for two resins conventionally modified using ETDA ion exchange resins based on S/DVB matrices. The microwave-modified resins reveal only slightly lower and in some circumstances even better sorption capacity for noble metals than their conventionally-modified equivalents. The differences are discussed by effect of the synthesis method as evaluated using FTIR spectrophotometry.     

A Comparison of Continuous Counter-Current Ion Exchange Equipment for Regeneration of Resins

Three distinct types of continuous counter-current equipment for regeneration of ion exchange resin have been investigated. A pulsed, multi-stage column, a horizontal multi-stage stirred tank apparatus (the Morris contactor) and a periodically moving packed bed of resin were used. The resin residence time characteristics and axial mixing patterns were assessed. The moving packed bed system is most satisfactory and it has been shown that it can be superior to fixed bed apparatus.     

The Coagulation of Finely-Divided Ion Exchange Resins and the Use of the Coagulated Material for Rapid Ion Removal

Abstract

Finely-ground ion exchange resin particles remove ions from solution much more rapidly than the conventional-size beads. Such finely-divided solids form suspensions when added to aqueous solutions. A method was required for rapidly removing such suspensions once ion adsorption had occurred, and to this end it is shown that the particles (-400 mesh) can be completely coagulated within a few minutes by the addition of suspensions of oppositely-charged solids. Thus anion exchange resins are coagulated by cation exchange resins (200 to 400), montmorillonite (200), kaolin (30), charcoal (10), silica (10), and glass (5), the figures representing arbitrarily defined relative coagulating abilities. Coagulating power is shown to increase markedly with decreasing particle size. Most suitable for ion removal is a mixed finely-divided resin formed by coagulation of anionic and cationic resins from pure water. The mixed resin, when added to 1 liter of 3 × 10^?4 M sodium phosphate solution removes all the phosphorus within 2 min, and when added to 1 liter of 2.5 × 10^?4 M calcium chloride, removes over 90% of the calcium within 3 min.     

7-苯乙酰胺基-3-氯甲基头孢烷酸对甲氧基苄酯C-3位卤离子交换反应研究

通过调整7-苯乙酰胺基-3-氯甲基头孢烷酸对甲氧基苄酯(GCLE)的C-3位卤素交换试剂的种类及用量,改变卤素交换反应水量,控制反应温度,明确反应时间,优化了GCLE的C-3位卤素交换的反应条件。结果表明:在n(碘化钠)∶n(溴化钠)∶n(GCLE)=0.1∶0.9∶1.0,v(水)∶w(GCLE)=1∶1,反应温度35℃,反应时间5 h的条件下,GCLE转化率99.71%,选择性97.63%。     

离子交换树脂中聚合物微球的生产工艺及装置改进

比较了制取聚合物微球的方法,指出了传统悬浮液聚合技术制备小白球的不足,并对喷射聚合小白球的生产工艺装置作了改进。     

离子交换法处理含硫酸铜废水的研究

运用离子交换法对电镀废水中硫酸铜进行吸附,富集废水中硫酸铜,达到回收再利用的目的。研究不同类型的树脂对硫酸铜吸附能力强弱,硫酸铜浓度及流速不同时树脂对硫酸铜的吸附能力。并且对树脂的解吸过程进行了研究,为低浓度含铜废水的合理回收提供依据。     

Hydraulic Testing of Ion Exchange Resins for Cesium Removal from Hanford Tank Waste

Abstract

The granular ion exchange resin SuperLig^® 644 is the ion exchange resin of choice for ¹³⁷Cs separation from Hanford tank wastes. Current testing activities are evaluating both ground gel and spherical resorcinol‐formaldehyde (RF) resins as alternatives to the sole‐source supplied SL‐644 while achieving comparable loading and elution performance. The purpose of this testing was then to compare the bed forces, resin particle breakage, and differential pressure across the resin bed during multiple load‐elute cycles. These tests were conducted in a small‐scale column with high flow rates to simulate the hydraulic conditions that would be experienced in a full‐scale column.     

Supercritical water oxidation of Ion Exchange Resins in a stirred reactor: Numerical modelling

Supercritical water oxidation offers a viable alternative treatment to destroy the organic structure of Ion Exchange Resins. In order to design and define appropriate dimensions for the supercritical oxidation reactor, a 2D simulation of the fluid dynamics and heat transfer during the oxidation process has been investigated. The solver used is a commercial code, Fluent^® 6.3. The turbulent flow field in the reactor, created by the stirrer is taken into account with a k?ω model and a swirl imposed to the fluid. Particle trajectories are modelled with the Discrete Random Walk Particle Model. For the solubilization of the particles in supercritical water, a mechanism has been proposed and implemented into Fluent^® software through the Eddy Dissipation Concept approach, taking into account the identified rate determining species. Simulation results provide results on the flow, temperature fields and oxidation localization inside the reactor. For the reactive particles-supercritical water flow model, the effect of parameters, such as feed flow rates or stirring velocity, can be focussed. Reaction temperature is predicted with deviation lower than 15%. Degradation conversions are in good agreement with experimental ones.     

碱性条件下NaY分子筛水热交换反应的研究

对碱性条件下的分子筛离子水热交换反应进行了研究。结果表明,离子交换反应为吸热反应,交换反应等温线为d型,交换反应为一级反应,表观活化能Ea为10．05kJ／mol。     

电子级超纯水精制混床离子交换树脂生产工艺分析

对电子工业中制备超纯水的精制混床离子交换树脂的生产工艺进行了分析与探讨,提供了一些思考。