萃取流量参数对稀土槽分布的影响

以国内某稀土厂生产萃取线A的La/CePr/Nd萃取过程为研究对象,通过采集和分析萃取槽各级有机相和水相中稀土元素的含量,明确不同皂化有机相流量、料液流量、酸流量等条件对各级稀土元素含量分布和稀土总量的影响。适当提高皂化有机相流量、料液流量和酸流量,可使水相出口处La的含量较高,从而保证出口产品纯度,但会使55级有机相出口处有机相中Ce组分含量较高,Pr、Nd组分含量较低,增加下一系列分离Pr、Nd的压力。     

Extraction of chromium(III) from sodium chloride solutions by means of carboxylic acids

Studies of Cr(III) extraction with carboxylic acids showed that the extraction process takes place at a pH of the aqueous phase ranging from 4 to 5. It was shown that sodium chloride is active with respect to chromium(III) as a salting-out agent. For extraction of Cr(III) with hexanoic acid it was shown that in the organic phase trinuclear complexes of the [Cr(OH)R₂·HR]₃ formula are formed.     

Solvent extraction of La（III） with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester （EHEHPA） by membrane dispersion micro-extractor

The conventional rare earth solvent extraction equipments have many problems such as long mixing time, low processing capacity, large factory area occupation, high energy consumption and so on. In order to solve the problems, many types of equipments were brought out. In this work, studies were carried out on the La（III） extraction process with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester （EHEHPA） by membrane dispersion micro-extractor. Equilibrium studies showed that the initial aqueous pH value 4.15 with the saponification rate 40%was the optimal operation condition. The effects of membrane dispersion micro-extractor operational conditions such as dispersion mode, bulk flow rate and organic phase flow rate on the extraction efficiency were studied. The results showed that when the organic solution was the dispersed phase, the extraction efficiency was higher than that of others. Increasing bulk flow ratio could enhance the extraction efficiency greatly. When the ratio of organic phase flow rate to that of aque-ous phase was 80：80, the extraction efficiency was over 95%. The effect of stripping phase acidity on the La（III） recovery was studied. The results showed that when the stripping phase pH was 2.0, organic phase flow rate to stripping phase flow rate was 20：80;the re-covery efficiency of La（III） can reach 82%.     

Investigation of the extraction kinetics of cobalt and nickel and the optimization of operation parameters in a mixer-settler for the extraction of cobalt

The extraction kinetics of cobalt and nickel in a mixer-settler have been investigated. The extraction system comprised an aqueous phase of cobalt and nickel sulphate and an organic phase of 10% EHPNA (2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester) -kerosene. The experimental results showed that the extraction rates of both cobalt and nickel were high and the extraction rate of cobalt was generally higher than that of nickel.On the basis of research on the extraction kinetics of cobalt, an optimization computation was carried out with total cost as the objective function, and the optimum combination of extraction stage efficiency with the extraction operation parameters was determined. The optimization computation showed that it is best to adopt high input power and short mixer contact time for the extraction of cobalt. The computations also showed that very high extraction stage efficiency is not required for minimum costs.     

电解质水溶液中钴、镍分离、提纯研究进展

高浓度、高纯度钴盐电解质水溶液是电解或电解精炼生产高纯乃至超高纯金属钴的关键.钴、镍离子深度地分离是制备该种电解质水溶液的核心任务.研究发现目前主要的分离、提纯方法包括:离子交换法、萃取色层法、膜分离法和溶剂萃取法等.研究对象主要集中在含高镍、低钴的硫酸盐水溶液体系.离子交换法、萃取色层法是实现两者深度分离的有效手段，溶剂萃取法则更易实现规模化.研究主要针对有机萃取剂和吸附材料的研发、改性、组合和分离提取工艺的改进等展开.文中对含钴、镍电解质水溶液中钴、镍分离研究进展进行总结评述，并对其发展进行展望.      

The solvent extraction of zinc chloride with di-n-pentyl pentaphosphonate

The extraction of divalent zinc from aqueous solutions containing sodium chloride using di-n-pentyl pentaphosphonate [C₅H₁₁PO(OC₅H₁₁)₂] in kerosene has been investigated.Equilibrium data were in good agreement with equations of the form x/y = a + bx, where coefficients a and b have been mathematically demonstrated to have a physicochemical meaning: a is the reciprocal of the distribution coefficient at infinite dilution and b is the reciprocal of the maximum loading capacity of the organic solution.By adjusting the extraction isotherms to such a type of equation by the least-squares method, the effects of chloride concentration in the aqueous phase and di-n-pentyl pentaphosphonate (DPPP) concentration in the organic phase were determined, showing that the extraction of divalent zinc from chloride solutions by DPPP proceeds according to the solvating reaction:

$\text{Zn}{}^{\mathrm{2+}}\text{(a) + 2Cl}{}^{\mathrm{?}}\text{(a) + 2 DPPP(o) ? ZnCl}{}_2\text{· 2DPPP(o)}$

where (a) and (o) represent aqueous and organic phases respectively.The extraction equilibrium constant of such a reaction was also determined, resulting in K_EX = (30°C). Moreover, a mathematical model for the extraction reaction was established, allowing the calculation of equilibrium data as a function of the initial aqueous chloride concentration and organic DPPP concentration. Values of such data are given in comparison with experimental data and their perfect agreement demonstrates the validity of the theoretical model which will be used in a computer program for process flow-sheet simulation.     

萃取法从高盐废液中分离铷铯并制备氯化铯产品

采用t-BAMBP－磺化煤油系配置的有机相对含铷、铯的高盐废液进行除钾试验,然后进行萃取分离试验,分别探索了硫酸铝用量与pH对除钾的影响,萃取过程中料液pH、萃取剂浓度、萃取时间、萃取相比、萃取级数对铷、铯萃取率,以及洗涤过程中洗涤相比、洗涤级数对铷铯洗脱率的影响。研究表明,料液pH=12.5、萃取相比O/A=1、选用1 mol/L萃取剂在室温下萃取5 min,铯萃取率可达99.95%。对高盐废液进行11级萃取(6级萃取、3级洗涤、2级反萃)连续试验,有机相中铯萃取率达99%以上,65%的铷留在水相中,可以较好地将铷与铯分离。最终制备出纯度98.3%的氯化铯产品。     

Use of Binary Extractants for Extraction and Separation of Noble Metals

The distribution of platinum metals and gold in the systems with binary extractants (salts of amines, quaternary ammonium bases (QAB), and organic acids) in toluene has been studied. It was shown that anion exchange mechanism complicated by interactions of components in organic phase is realized during metal extraction from 1–3 M HCl solutions. When acidity of aqueous phase decreases distribution coefficients of noble metals are decreased according to binary extraction regularities of mineral acids in (he systems with salts of trioctylamine and QAB. In the systems with caprylate and alkylphenolate of dioctylamine in the region of high pH values of aqueous phase, palladium distribution coefficients are increased due to formation in the organic phase of complexes with direct coordination of amine molecules to atoms of palladium and their stability is, obviously, higher than that of dioctylamine salts with corresponding organic acids. From the investigated binary extractants, the salts of quaternary ammonium bases and strong organic acids (alkylphosphoric, alkylbenzolsulfonic acids) are of great interest for practice. It was shown during extraction of Pt (IV), Pd (II), Ir (IV) and Au (III) chlorocomplexes by 0.1 M solutions of trialkylbenzylammonium alkylsulphonate, metal distribution coefficients in the acidic region are changed from 5 to 150 while distribution coefficients for Rh(III) and Ir(III) did not exceed 0.1 and that creates possibilities for separation of platinum metals. Noble metals are lightly stripped from organic phase by water that it is impossible for initial systems with mineral salts of quaternary ammonium bases. The comparison of the systems with binary extractants and TBP has shown the advantage of binary extraction for obtaining more concentrated stripping solutions.     

含Ni~(2+),Fe~(3+),Mg~(2+)的硫酸盐溶液萃取分离Cu~(2+)

采用Lix984作萃取剂,煤油作稀释剂混合而成溶液萃取的有机相,从含Ni~(2+),Fe~(3+),Mg~(2+)离子的硫酸盐溶液中萃取分离Cu~(2+).实验结果表明,在一定范围内,铜萃取率随萃取剂浓度的升高、相比的增加、萃取时间的延长、初始水相pH值的增加、萃取温度的升高以及搅拌时间的延长而增加.本实验的优化条件为萃取剂体积分数达60%,相比为O∶A=2∶1,萃取时间为16 min,萃取初始水相pH值为2.5,萃取温度在25~45℃之间,搅拌速度为240 r/min.在最佳条件下,铜萃取率高达95.55%.Fe~(3+)萃取率为8.82%,Ni~(2+)的萃取率为5.47%,Mg~(2+)的萃取率为2.36%.从而达到Cu~(2+)与其它金属离子有效分离的效果.     

氯离子作用下N235对铋的萃取性能

采用溶剂萃取法脱除铜电解液中的杂质,在水相料液中添加助萃剂Cl-,研究Cl-作用下萃取剂N235对铋的萃取性能.考察有机相N235体积分数、水相助萃剂Cl-浓度、有机相与水相的体积比 (相比)、萃取时间、萃取温度等因素对铋萃取率的影响.研究结果表明:有机相N235体积分数、水相助萃剂Cl-浓度和相比是影响铋萃取率的主要因素;较为适宜萃取铋的条件为:水相硫酸浓度为3.0 mol/L,氯离子浓度为0.1 mol/L,萃取剂N235体积分数为20 %,相比为1:1,萃取时间为5 min.在此实验条件下,铋的一级萃取率达到97.3 %(质量分数).      

Extraction of vanadium from direct acid leach solution of converter vanadium slag

Direct acid leaching of converter vanadium slag by titanium dioxide waste is eco-friendly and efficient, but with low selectivity. This novel technique can result in a vanadium solution which contains chromium(III), aluminium(III), magnesium(II), manganese(II) and high amount of iron(II) and iron(III). Bis (2-ethylhexyl) phosphoric acid (D2EHPA) and tri-butyl-phosphate (TBP) diluted with sulphonated kerosene were applied for vanadium extraction from the multi-element leach solution. The effects of the initial pH, concentration of D2EHPA, ratio of organic to aqueous phase, and the extraction time on the extraction efficiency of vanadium were investigated in saponification and unsaponifiable systems, respectively. The results showed that the vanadium extraction percentage can be up to 97% and the iron extraction percentage can be less than 10% in a thirteen-stage counter-current simulation test and the separation coefficient between vanadium and iron can reach to 109.8. Furthermore, vanadium(IV) can also be separated from other impurities such as aluminium(III), magnesium(II), manganese(II), chromium(III) efficiently. The loaded organic phase was stripped by 184?g?L^?1 sulphuric acid solution in a three-stage counter-current stripping process and with the total vanadium stripping percentage of greater than 99.5%. In the end, the vanadium pentoxide products with a purity of 99.14% were obtained.     

Alteration of signal-transducing molecules in tumor-infiltrating lymphocytes and peripheral blood T lymphocytes from human colorectal carcinoma patients

An analytical method for the rapid isolation and recovery of the homologous series of 2-aminoethanols, a class of organic compounds of importance to wood preservative treatment, is successfully developed. The method is applied to an aqueous solution of copper amine (copper[II] hydroxide complexed monoethanolamine) and to copper-amine-treated sawdust. The method incorporates a gas chromatograph-ion-trap mass spectrometer. A discussion of the secondary equilibrium effects involved when ionizable analytes are extracted from an aqueous phase with respect to organic bases is presented. Using 2-propanol as the extractant coupled to a salt-saturated aqueous phase results in recoveries of 63% for 2-aminoethanol, 51% for N,N-dimethyl-2-aminoethanol, and 56% for N-methyl-2-aminoethanol for a single liquid-liquid extraction. The choice of 2,2,2-trifluoroethanol as an internal standard is found to be quite suitable. A comparison of the precision and accuracy for an external versus an internal mode of instrument calibration demonstrates that the internal standard mode is preferable for this manual injection.     

P2O4萃取硫酸体系中V(Ⅳ)、Fe(Ⅲ)的分离性能研究

针对传统提钒技术存在的能耗高、污染重、钒回收率低等缺点,提出钛白废酸无焙烧加压酸浸提钒新技术,以该工艺浸出液为研究对象,通过组分优势区域图、正交试验以及单因素试验,探究P204萃取硫酸体系中V(Ⅳ)、Fe(Ⅲ)的分离性能.试验结果表明:当pH小于2时,V(Ⅳ)在水溶液中主要以VO2+形式存在,Fe(Ⅲ)在水溶液中主要以Fe3+形式存在;相比(O/A)是影响V(Ⅳ)、Fe(Ⅲ)萃取率的重要因素;在较优萃取条件下:有机相组成30％P204+10％ TBP+60％磺化煤油,温度T=30℃,震荡时间8min,水相初始pH值为1.6,相比(O/A)为3,V(Ⅳ)的萃取率为61.16％,Fe(Ⅲ)的萃取率为18.87％,钒铁分离系数为6.67.     

Rate Processes in Solvent Extraction of Metal Ion

Abstract

The mechanism and kinetics of metal extraction with several extractants, including chelating agents, acidic organophosphorous extractant and neutral extractants are discussed in this paper.

Firstly the extraction rate of metal ion for the general extraction system is formulated by solving the diffusional equation with chemical reaction, in which the interfacial reaction is considered by the boundary conditions. The overall rate expressions of the complex formation with chelating agents are obtained both in aqueous phase and at the interface. The general formula of the extraction rate is simplified by considering the rate-determining steps.

Next, the extraction rate of metal ion with chelating agents and acidic organophosphorous extractants is discussed. For the chelating agents, the most important properly to determine the locus of complex formation is the distribution constant between the organic and aqueous phases. The contribution of the interfacial reaction to the extraction rate increases with the increase in the distribution constant of chelating agents. The extraction rate of many metal ions with acidic organophosphorous extractant are determined by the diffusion process of final complex in the organic phase.

Finally, the extraction rate of palladium ion with some neutral extractants is also discussed. The extraction rate is determined by the complex reaction in the aqueous phase and at the interface. The contribution of the interfacial reaction increases with the distribution constant of extractants.     

Relationship of Purity Gradient and Accumulation with Feed Compositionin TwoComponent Countercurrent Extraction System

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The modelling of equilibrium data for the liquid-liquid extraction of metals part III. An improved chemical model for the copper/LIX 64N system

New data are presented for the copper sulphate—sulphuric acid/LIX 64N—Escaid 100 solvent extraction system, and it is shown that these data do not exhibit the anomalous features of Robinson's (1971) results. The data are modelled using equations based on the thermodynamics of the Cu²⁺, CuSO₄, H⁺, HSO₄^?, SO₄^2? aqueous system and the HR, (HR)_n, CuR₂ organic sytem (where HR represents the active β-hydroxyoxime in LIX 64N). Although the values of the two aqueous and the two organic equilibrium constants cannot be held to have thermodynamic significance, the best models are capable of predicting the organic copper concentrations of the 86 data points at four different concentrations of LIX 64N (5–50 vol.%) from the aqueous phase analyses with average errors as low as 7%. Isotherms for desired aqueous feedstocks and desired concentrations of our batch of LIX 64N in Escaid 100 at 25–26°C can be calculated.     

A GENETIC ALGORITHMS BASED MULTI-OBJECTIVE OPTIMIZATION APPROACH APPLIED TO A HYDROMETALLURGICAL CIRCUIT FOR OCEAN NODULES

Several hydrometallurgical processes have been studied for the extraction of metals from lean ores utilizing various flow sheet options. Of particular significance is the grade of the ore being treated, the energy consumed and associated costs, options for byproduct recovery, and the relative price of the products. A process scheme needs to be optimized for simultaneously maximizing metal throughput and minimizing the direct operating costs incurred within constraints set for the operating variables. This leads to a multi-objective optimization problem. The range of input grades for raw material, which a flowsheet can handle, needs to be worked out based on an optimization exercise. A lean manganese-bearing resource such as polymetallic sea nodules has been chosen in this article for the development of an optimization approach based on which the input raw nodules grades are to be treated by a particular flowsheet. Only the chemical consumption costs have been adopted in this article as a measure of direct operating costs. A linear simulation model for the flowsheet has been developed, keeping a set of design parameters constant. The solutions generated by using a sequential modular approach become inputs to an optimization procedure based on a multi-objective genetic algorithm belonging to the differential evolution family. The variables considered in the optimization task are the grade of nodules and reactivity of different species inside the reactor. A nickel equivalent (t/h function) has been suggested as a measure of productivity, as it indirectly enhances the input manganese ore grade through a price ratio effect. This productivity function was maximized with the simultaneous minimization of direct chemical costs. Pareto optimal solutions were generated with grades of nodules and reactivity in the leach reactor as decision variables. The effect of the price ratio on the Pareto optimal solutions was also investigated. The various cases investigated clarifies the methodology for choosing an appropriate ore grade range for a given process flowsheet. Appropriate decisions regarding the nature of raw material to be used for a given flowsheet are then found on the basis of the Pareto optimal solutions.     

ACORGA ZNX50—a new selective reagent for the solvent extraction of zinc from chloride leach solutions

The new reagent ACORGA ZNX50 is a formulation of a novel class of reagent developed by ICI specifically for the solvent extraction of zinc from aqueous chloride solutions. The reagent shows remarkably high selectivity for zinc over iron and various other metals including lead, cadmium and antimony.Such reagents are of potential application in new systems, such as hydrometallurgical processes for the recovery of metals from complex sulphide ores based on chloride leaching, solvent extraction, and direct electrowinning from chloride solution. The reagents are also applicable to the recovery of zinc from chloride-containing effluent streams and solutions produced by the chloride leaching of zinc-bearing wastes.ACORGA ZNX50 gives efficient extraction of zinc at ambient temperature from solutions approximately 4–8 molar in chloride ion. The loaded organic phase is readily stripped at 60–65°C using either water, dilute brine, or spent zinc chloride electrolyte. Test work and trials carried out in laboratoy-scale mixer-settlers have confirmed the hydrometallurgical properties, including extraction, stripping, selectivity, good phase separation and long-term stability of the reagent.     

Technology of Chloride-Ion Utilization from Filtrates of Carbonate Circuit of Nickel Production

The problem of sulphate solution purification, in particular solutions of carbonate branch after nickel precipitation, from chloride ion can be solved effectively by extraction process. Trialkylamine available commercially (TAA) (alkyl—C₈-C₁₀ and C₇-C₉) has been used in this study. The dependences of chloride ion extraction on temperature, pH and composition of aqueous phase, and composition of organic phase have been investigated. Triethylbenzene, kerosene, diesel oil, syntin with different additions (2-ethylhexanol, hexanol, tributylphosphate) were used as the solvents. The optimum composition of organic phase (0.5-0.6 M TAA in kerosene with addition of 2-ethylhexanol) and the conditions of chloride ion extraction from sulphate solutions have been determined. Chloride ion stripping from organic phase was conducted by alkali solutions to obtain a concentrated solution of sodium chloride.

The technology of chloride ion recovery from filtrates of carbonate branch of nickel plant (Norilsk Mining and Metallurgical plant) has been developed and tested on an industrial scale. The initial filtrate contained in g/l: chloride ion I6-I8, sulphate ion 60-65, impurities of metals. After purification, the chloride ion concentration in solution was less than 0.3 g/l (chloride ion recovery was more than 95%). After stripping of chloride ion with alkali solution, the stripping solutions containing 200-220 g/l NaCl and < 2 g/l sulphate ion. The stripping solutions underwent an electrolysis to obtain chlorine and sodium hydroxide solutions.

The developed technology allows recovery of chloride ion from sulphate solution.     

Solvent extraction of uranium from dilute solutions using a gas-bubble mixed extraction column

A modified solvent extraction process for recovering uranium from very dilute solutions, such as mine waters or copper dump liquors, has been developed and tested on a laboratory scale. The system utilizes a column in which the aqueous feed flows downward through a liquid organic extractant. A countercurrent flow of gas is used to achieve mixing and enhance mass transfer. Acid sulfate solutions at pH 1.5 containing either 0.010 or 0.015 g/1 U₃O₈ comprised the feed. The extractant used was Alamine® 336 dissolved in fuel oil. Critical parameters of the system, such as length to diameter ratio of the organic phase, volume ratio of aqueous to organic in the column, and flow rates of aqueous feed and gas are examined.