Separation of Copper and Nickel from Ammoniacal/Ammonium Carbonate Solutions Using ACORGA PT5050

ABSTRACT

ACORGA PT5050 diluted with iberfluid (kerosene-type diluent, mostly aliphatic) was used to coextract copper and nickel from ammoniacal carbonate solutions. The influence of kinetics, temperature, equilibrium pH, and extractant concentration on the extraction of both metals has been studied. It was observed that nickel extraction is very sensitive to aqueous pH and that the extraction falls beyond an equilibrium pH of 9. For a typical solution containing near 3 g/L each of copper and nickel and 60 g/L ammonium carbonate, conditions were established for the coextraction and selective stripping of nickel and copper.     

DILUENT EFFECT ON THE EXTRACTION OF URANIUM(VI) FROM HYDROCHLORIC ACID SOLUTIONS BY TRIOCTYLMETHYLAMMONIUM CHLORIDE

ABSTRACT

The extraction of uranium(VI) from hydrochloric acid solutions by trioctylmethylammonium chloride (TOMAC) has been examined using various diluents such as benzene, chlorobenzene, o-dichlorobenzene, toluene, m-xylene, nitrobenzene, carbon tetrachloride, chloroform and 1,2-dichloroethane. It was found that by assuming a regular solution, the distribution coefficient and the enthalpy change associated with the metal extraction can be expressed in terms of the solubility parameter of TOMAC, diluent and the complex formed in the organic phase and their molar volumes. Additionally an empirical relation holds between distribution coefficient and the viscosity of diluent. Further results for the extraction of divalent manganese, cobalt, copper, zinc and cadmium from hydrochloric acid solutions by TOMAC are investigated in comparison with those of uranium(VI).     

Rheological Behavior of Vinyl Ester Resin

Vinyl ester resins with varied acid values (11, 22, 32, 38, and 48 mg KOH/g solid) were prepared by reacting epoxy-novolac resin with methacrylic acid. The rheological behavior of these synthesized vinyl ester resin (VER) samples containing styrene as reactive diluent was studied using a Haake Rotovisco RV 20 viscometer. The apparent viscosity was found to be inversely proportional to the square root of the acid value in the temperature range of 25–40°C and at shear rates ranging from 100–800 sec^?1. The zero-shear viscosity of these VER samples containing styrene (40% w/w) as reactive diluent decreased linearly with temperature. The activation energies for flow at constant shear stress (25–100 Pa) for a particular sample were found to be constant. The activation energy at constant shear rate decreases with the increase in the shear rate (50–400 sec^?1). The activation energy at constant shear rate and shear stress decreased with the increase in the acid value. The viscosity of vinyl ester resin containing styrene as reactive diluent decreased almost 50 times with the increase in the concentration of reactive diluent from 30% to 100% (w/w of the resin).     

Separation and Preconcentration of Cesium from Acidic Media by Extraction Chromatography

Abstract

A novel extraction chromatographic resin for the separation and preconcentration of cesium from acidic nitrate media comprising an inert polymeric substrate impregnated with 1,3‐calix[4]bis‐o‐benzo‐crown‐6 (“BC6B”) in a chlorinated diluent is described. Cesium is shown to be both strongly and selectively retained by the resin at low (<1 M) acid concentrations and readily eluted from it using 6 M HNO₃. Only potassium ion (at concentrations exceeding ca. 0.01 M) exerts a significant adverse impact on cesium retention. Unexpectedly, cesium uptake by the resin does not exhibit the acid dependency anticipated from liquid‐liquid extraction data. This is also the case for a resin employing a related macrocyclic extractant, calix[4]arene‐bis‐(t‐octylbenzocrown‐6) (“BobCalix”), prepared and partly characterized in an effort to overcome certain limitations of the BC6B‐based material. Despite this, the resin is shown to be well suited to the isolation of radiocesium from acidic solution for subsequent determination or for the removal of cesium intereference in the quantitation of other radionuclides.     

Extraction of Copper by Selective Ion Exchangers with Pendent Ethyleneimine Groups—Investigation of Active States

Abstract

Selective ion exchangers with pendent ethyleneimine groups of the type -(NHC₂H₄)n · NH₂, where n = 1 to 5, have been prepared, and their ability to extract cationic and anionic-chelated copper(II) ions has been evaluated. Copper has been extracted from aqueous solution, and the equilibrium capacities of extraction vary according to the active sites in the selective ion exchangers. The poor exchange properties of selective ion exchangers with short pendent groups have been related to the nature of the active coordination sites. The active sites on these selective ion exchangers change from two nitrogen atoms and two oxygen atoms (N₂O₂) with short chains (n = 1) to four nitrogens when n = 2 to 5. Those which have N₄ active sites appear to extract cationic copper(II) efficiently, but those with N₂O₂ sites have low capacities and copper is easily leached from the resin even when the loading of the resin is low. When copper is complexed to EDTA to form an anionic complex, a side chain like pentaethylene hexamine is required to extract the copper from aqueous solution. A macroporous polystyrene resin had a lower capacity for anionic chelated copper than a polystyrene gel resin with the same functional groups due to the poorer accessibility of the active (N₄) sites to the large anion.     

Metal-Metal Chelating Ion-Exchange Processes on 8-Hydroxyquinoline and 8-Hydroxyquinaldine Resins

Abstract

The metal capacity vs pH contours and the separation ratios for copper, zinc, and aluminum have been studied for an oxine-containing, chelating ion-exchange resin. Metal-metal exchange studies on this resin involving the three metals have demonstrated that this is not a simple substitution process, sorption and desorption of the ions being controlled by solution concentration. The sterically hindered ligand, 8-hydroxyquinaldine, incorporated in a resin, demonstrated much greater selectivity for other metals over aluminum and confirmed published solvent extraction data for this ligand.     

Ion Exchange on LIX 65N and Kelex 100 Impregnated Foams

Abstract

The metal capacity vs pH contours and the separation ratios for copper, zinc, and aluminum have been studied for an oxine containing, chelating ion-exchange resin. Metal-metal exchange studies on this resin involving the three metals have demonstrated that this is not a simple substitution process, sorption and desorption of the ions being controlled by solution concentration. The sterically hindered ligand, 8-hydroxyquinaldine, incorporated in a resin, demonstrated much greater selectivity for other metals over aluminum and confirmed published solvent extraction data for this ligand.     

Selective Separation of Gallium from Acidic Leach Solutions by Emulsion Liquid Membranes

Abstract

The separation and concentration of gallium from acidic leach solutions, containing various other ions such as iron, cobalt, nickel, zinc, cadmium, lead, copper, and aluminium, by an emulsion liquid membrane (ELM) technique using tributyl phosphate (TBP) as carrier has been presented. Liquid membrane consists of a diluent, a surfactant (ECA 4360J), and an extractant (TBP), and 0.1 M HCl or 0.1 M H₂SO₄ were used as the stripping solution. The important variables governing the permeation of gallium and their effect on the separation process have been studied. These variables were membrane type and composition, mixing speed, diluent type, surfactant concentration, extractant concentration, HCl concentration in the feed, acid type of stripping phase, feed concentration, and treatment ratio. The optimum conditions were determined. It was possible to selectively extract 96.0% of gallium from the acidic leach solutions, containing Fe, Co, Ni, Zn, Cd, Pb, Cu, and Al, at the optimum conditions.     

Supported Liquid Membrane Separation of Aluminum from Copper Leaching Liquors

Abstract

The Bureau of Mines, U.S. Department of the Interior, investigated the separation of aluminum from copper dump leaching liquors using a supported liquid membrane. Aluminum was selectively transported through porous polypropylene impregnated with di(2-ethylhexyl) phosphoric acid in an aliphatic diluent. The effects of variables, such as solution composition, temperature, and extractant concentrations, were measured using a three-level fractional factorial experimental design. Experimental results were used to derive equations for predicting transport rates for aluminum, iron, and copper. The major variables influencing aluminum transport were solution temperature, feed solution pH, aluminum concentration in the feed solution, and extractant concentration. Copper and iron transport rates were almost zero when aluminum transport rates were high. Measured aluminum transport rates under the best conditions of 55[ddot] C, pH 3.0, 16 g/L A1³⁺ and 65 pet extractant solution confirmed the predicted value of 210 μg/(cm²·h). Transport rates for iron and copper were less than 5 μg/(cm²·h) under these conditions.     

Ligand-Exchange Chromatography of Amino Acids on Copper-Loaded Chitosan

Abstract

Amino acids are retained on the copper form and on the amino copper form of chitosan, especially aspartic acid, glutamic acid, tryptophan, and cysteine. The best conditions for collection and for elution are in phosphate buffers at pH 7 and 12, respectively. No leakage of copper occurs; the amino acids are recovered as copper complexes with a ratio of 1:2 copper: amino acid. Several advantages of chitosan over the resin Chelex are pointed out; namely, absence of swelling, great copper capacity. hydrophilicity, and porous structure.     

Extraction of copper from dilute solutions by LIX 64N. Effect of dekalin and tetralin as diluents on the equilibrium and rate of mass transfer

Liquid-liquid equilibrium data and mass transfer rates for the extraction of copper from dilute aqueous sulphate solutions by LIX 64N with dekalin (decahydronaphthalene) and tetralin (1,2,3,4-tetrahydronaphthalene) as diluents are reported. The stripping of copper from the organic phase was also studied. For an initial copper concentration of 1.5 g dm^?3 extraction efficiency decreases as the concentration of tetralin increases in the diluent mixtures of dekalin-tetralin. This behaviour is explained as a result of the formation of oxime aggregates and the interaction between the oxime and the diluent. Initial rates of extraction and stripping were determined by the single drop technique. The linear relation between initial rates of extraction and the difference of interfacial tension between the extractant in the diluent and the diluent itself holds for the system under investigation.     

Sorption of Metals by an Amidoxime Chelating Resin. Part I: Equilibrium

ABSTRACT

The complexation equilibrium of metals (copper, lead, and zinc) by using a chelating ion-exchange resin (Duolite ES-346) is analyzed. Two potentiometric titrations of the resin which allow evaluation of the exchange capacity and the pKvalues are carried out. Two equilibrium models (mass action type model and surface complex formation model) are proposed, and their parameters are estimated by fitting model equations to data from batch experiments. The degradation of the amidoxime groups in acidic media and a possible way to minimize that problem is discussed.     

Hydrometallurgy Wastewater Split-Up by Fluidized-Bed Ion-Exchange Continuous Equipment

ABSTRACT

A proposed operation of a semicontinuous fluidized-bed ion-exchange system was studied. The system splits a liquid current into two currents, one being more concentrated and the other more depleted. This operating technique has been used to split up a mixture of alkaline ions (Na⁺, K⁺) using a strongly acidic resin. The equipment operates simultaneously in two multistage columns, one for loading and the other for elution of the resin. The experimetal testing system employs a hydrometallurgy wastewater containing cobalt and copper as heavy metallic ions, and the resin used was of the chelating iminodiacetic type, Lewatit TP-207. At cyclic steady state, the equipment can split up the wastewater, producing an effluent concentrated in cobalt in the outlet stream of the loading column, and a concentrated stream of copper in the effluent of the elution column. The hydrodynamics and approach to the stationary state of the system were analyzed, and the selective recovery of metals was subsequently tested experimentally. This behavior presents certain similarities with a parametric pumping operation of the system, with the two columns operating at different pH values or temperatures.     

Solvent Extraction of Copper from Nitrate Media with Chelating LIX‐Reagents: Comparative Equilibrium Study

Abstract

Comparative experimental studies were carried out on extraction of copper(II) cations from aqueous acid nitrate media using four LIX‐reagents, representatives of different extractant classes: LIX 984N‐I, LIX 860N, LIX 84‐I and LIX 65N. As a diluent, liquid hydrocarbon undecane was used. The extraction behavior of the LIX‐reagents was compared based on an analysis of the influence of the main factors on the two‐phase mass transfer process: aqueous pH‐value, initial copper and extractant concentrations, and temperature. The experimental data received were used in the calculation of important parameters characterizing the efficiency of copper extraction from nitrate media with different LIX reagents: distribution ratios D, concentration extraction constants K _ex, pH_0.5‐values, and thermodynamic parameters such as enthalpy, entropy, and free energy changes (ΔH ⁰, ΔS ⁰, ΔG ⁰‐values).     

Dual-Temperature Ion-Exchange Separation of Copper and Zinc by Different Techniques

Abstract

Separation of copper from zinc-containing acidic solutions has been advanced by different techniques of dual-temperature ionexchange fractionation on iminodiacetic resin Amberlite IRC 718. Cycling-zone adsorption and parametric pumping (using single-column as well as double-column set-ups) experiments have been carried out in fixed-bed ion-exchange column. Measurement of equilibrium characteristics of the resin-solution system has shown that separation results from the variation of the ions sorbability with temperature. It has been found that temperature variation leads to reverse of selectivity between copper and hydrogen ions. Cycling-zone adsorption technique has allowed the copper content to be decreased up to 4 times in the resin phase and increased up to 1.7 times in the effluent when carrying out the process at 80 and 20 °C, respectively. The copper concentration has been decreased 4.4 fold after 9 treatment cycles of solution aliquot (15 BV) by single-column mode of the parametric pumping method. Two steps of the fractionation process (loading and elution) have been performed by continuous mode of operation in two counter-current columns. Continuous separation is preferred over fixed-bed column techniques. The steady-state sorption fronts have been formed on both stages of the process due to the reverse of selectivity mentioned above.     

Surface Modification of a Photo-Definable Epoxy Resin with Polydopamine to Improve Adhesion with Electroless Deposited Copper

Abstract

This paper describes the influence of polydopamine surface modifications on the adhesion strength of electroless deposited copper on roughened epoxy resin substrates. The surfaces are characterized with XPS and ToF-S-SIMS. Next, a thorough investigation of the copper–epoxy interface is performed using SEM. Both the polydopamine modification and the variation of the electroless plating bath temperature lead to new insights into the different contributions of chemical and physical adhesion to the overall adhesion strength.     

Separation and Recovery of Silver(I) Ions from Base Metal Ions by Melamine‐formaldehyde‐thiourea (MFT) Chelating Resin

Abstract

Melamine‐formaldehyde‐thiourea (MFT) chelating resin were prepared using melamine (2,4,6‐triamino‐1,3,5‐triazine), formaldehyde, and thiourea and this resin has been used for separation and recovery of silver(I) ions from copper(II) and zinc(II) base metals and calcium(II) alkaline‐earth metal in aqueous solution. The MFT chelating resin was characterized by elemental analysis and FT‐IR spectra. The effect of pH, adsorption capacity, and equilibrium time by batch method and adsorption, elution, flow rate, column capacity, and recovery by column method were studied. The maximum uptake values of MFT resin were found as 60.05 mg Ag⁺/g by batch method and 11.08 mg Ag⁺/g, 0.052 mg Zn²⁺/g, 0.083 mg Cu²⁺/g and 0.020 mg Ca²⁺/g by column method. It was seen that MFT resin showed higher uptake behavior for silver(I) ions than base and earth metals due to chelation.     

SPECIATION STUDY ON THE ION EXCHANGE EXTRACTION OF SILVER,COPPER, IRON AND ZINC CYANO COMPLEXES WITH AN ITERATIVE SLOPE ANALYSIS TECHNIQUE.

ABSTRACT

A slope analysis technique was developed and applied to the study of various equilibrium distribution isotherms in order to determine the speciation involved in the ion exchange. The slope analysis technique consisted of a computer iterative procedure to estimate the equilibriura resin composition and the introduction of ‘macro’ concentrations of a foreign anion to induce limiting conditions.

The results indicate that, under the experimental conditions and with tht resi.is studied, both copper and ziac are extracted mainly as bivalent ions. Evidence was found that iron is extracted as a tetravalent ion whereas silver appears to be extracted as a mixture of mono- and bivalent ions.     

Effect of NBR on epoxy/glass prepregs properties

Solid acrylonitrile‐butadiene rubber (NBR) was used in epoxy resin for toughening and also for increasing the tack of epoxy/glass prepregs. The NBR used in this study was a rubber with 33% acrylonitrile content. The changes in thermal and mechanical properties such as glass transition temperature (T_g), curing characteristics and lap‐shear strength have been studied. For this purpose, three types of prepregs with two levels of NBR content of 3 and 5%, were prepared. Prepregs were made by solvent type impregnation apparatus. In this method, resin impregnates satin textile glass fiber under the controlled and constant condition of line speed and oven temperature. Prepregs were B‐staged for about 3%. The cure characterization, T_g and flow behavior were evaluated using differential scanning calorimetry and rheological analysis. Results showed that increasing the rubber content caused the following effects: (a) delay in gel time of prepregs, (b) increase in activation energy of prepregs, and (c) decrease in total heat of curing reaction. It is interesting that NBR increased the tack of epoxy/glass prepreg but, had no effect on its resin flow behavior. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Addition of a reactive diluent to a catalyzed epoxy-anhydride system. II. effect on enthalpy relaxation

Enthalpy relaxation in an epoxy resin based on diglycidyl ether of bisphenol A (DGEBA) with a reactive diluent cured with methyl-tetrahydrophthalic anhydride (MTHPA) with an accelerator was investigated by differential scanning calorimetry. The reactive diluent (RD) added was an aliphatic diglycidyl ether which was mixed in a proportion of 50 parts by weight (pbw) per 100 parts of DGEBA, with the stoichiometric quantity of MTHPA. The key parameters of the enthalpy relaxation investigated were the nonlinearity parameter, x, the apparent activation energy,Δh^*, and the nonexponentiality parameter, β. The results were compared with other data obtained previously in similar epoxy-anhydride systems without an RD but with different degrees of conversion in order to analyze the effects of (a) the introduction of aliphatic chains of the RD in the epoxy structure and (b) a reduction in the crosslink density of the resin. © 1997 John Wiley & Sons, Inc.