Selective extraction of cobalt from strong acidic solutions containing cobalt and nickel through emulsion liquid membrane using TIOA as carrier

Recep Ali Kumbasar 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.6

The present investigation deals with carrier-facilitated membrane transport of cobalt from strong acidic leach solutions containing cobalt and nickel by emulsion liquid membrane (ELM) using triisooctylamine (TIOA) as carrier. In this work, the zinc plant copper cake was leached with hydrochloric acid solution and main acidic leach solution containing various ions was obtained. After various ions in the acidic leach solution were separated, optimum conditions were determined. The results showed that it is possible to extract 99% of cobalt using ELM from strong acidic leach solutions, containing cobalt and nickel ions, at the optimum conditions.

Extraction and concentration of cobalt from acidic leach solutions containing Co–Ni by emulsion liquid membrane using TOA as extractant

Recep Ali Kumbasar 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.3

The present investigation deals with carrier-facilitated membrane transport of cobalt from acidic leach solutions containing cobalt and nickel by emulsion liquid membrane (ELM). In this work, the zinc plant electrolyte purification was leached with hydrochloric acid and main acidic leach solution containing Zn(II), Cu(II), Fe(II), Cd(II), Co(II) and Ni(II) ions was obtained. After Zn(II), Cu(II), Fe(II) and Cd(II) ions in the acidic leach solution were separated, the important parameters influencing the extent of cobalt extraction were investigated and optimumconditions were determined. Cobalt transport was influenced by number of parameters like cobalt initial concentration, mixing speed, extractant concentration,surfactant concentration, the stripping solution type and concentration, and the feed solution acid concentration. After the optimum parameter values were determined, cobalt from the acidic leach solution containing 100 mg Co/L and 200 mg Ni/L was almost completely extracted within 10 min. The results showed that it is possible to extract 99% of cobalt by using ELM from the acidic leach solutions containing Zn(II), Cu(II), Fe(II), Cd(II), Co(II) and Ni(II) ions at the optimum operating conditions. 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Extraction of cadmium from solutions containing various heavy metal ions by Amberlite LA-2

Recep Ali Kumbasar 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.2

In present study, selective extraction of cadmium from acidic leach solutions, containing various heavy metal ions, by emulsion liquid membrane (ELM) is studied. For this reason, the zinc plant copper cake was leached with sulfuric acid and main acidic leach solution containing Zn(II), Cu(II), Fe(II), Cd(II), Co(II) and Ni(II) ions was obtained. After Zn(II), Cu(II), Fe(II) and Cd(II) ions in the acidic leach solution were separated, the important parameters influencing the extent of cadmium extraction were investigated and optimum conditions were determined. Cadmium extraction was influenced by number of parameters like initial metal ion concentration, mixing speed, phase ratio, extractant concentration, surfactant concentration, the stripping solution type and concentration, and the feed solution acid concentration. The optimumvalues of parameter abovementioned were used and cadmium in the acidic leach solution containing 650 mg Cd/L, 365 mg Co/L, 535 mg Ni/L, and 1260 mg Zn/L was almost completely extracted within 10 min. The results showed that it is possible to extract 99% of cadmium after 10 min contact time by using ELM from aqueous solutions, containing Fe(II), Al(III), Cu(II), Zn(II), Pb(II), Co(II) and Ni(II) ions, at the optimum operating conditions.

Selective transport of cobalt (II) from ammoniacal solutions containing cobalt (II) and nickel (II) by emulsion liquid membranes using 8-hydroxyquinoline

Recep Ali Kumbasar 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1

The selective transport of cobalt (II) from ammoniacal solutions containing nickel (II) and cobalt (II) by emulsion liquid membranes (ELMs) using 8-hydroxyquinoline (8-HQ) as extractant has been presented. Membrane solution consists of a diluent (kerosene), a surfactant (ECA 4360J), and an extractant (8-HQ). Very dilute sulphuric solution buffered at pH 5.0 has been used as a stripping solution. The ammoniacal feed solution pH was adjusted to 9.0 with hydrochloric acid. The important variables governing the permeation of cobalt (II) have been studied. These variables are membrane composition, pH of the feed solution, cobalt (II) and nickel (II) concentrations of the feed solution, stirring speed, surfactant concentration, extractant concentration, complexing agent concentration and pH of the stripping solution, and phase ratio. After the optimum conditions had been determined, it was possible to selectively transport 95.0% of cobalt (II) from ammoniacal feed solution containing Co2+ and Ni2+ ions. The separation factors of cobalt (II) with respect to nickel (II), based on initial feed concentration, have experimentally found to be of as high as 31 for equimolar Co(II)–Ni(II) feed solution.

Selective extraction and concentration of chromium(VI) from acidic solutions containing various metal ions through emulsion liquid membranes using Amberlite LA-2

Recep Ali Kumbasar 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.5

Chromium(VI) is a very harmful metal, highly toxic and carcinogenic in nature. Its separation from industrial effluents is of primordial importance. An extensive study on selective extraction and concentration of chromium(VI) from the acidic solutions containing various metal ions using an emulsion liquid membrane (ELM) technique is presented. The ELM consists of Amberlite LA-2 as an extractant, commercial kerosene as organic solvent, ECA 4360J as a surfactant and 0.5 M ammonium carbonate solution as stripping phase. The study has highlighted the importance and influence of membrane composition for maximizing the extraction of chromium(VI). For this reason, effects of various parameters such as chromium(VI) concentration in the acidic solution, mixing speed, type and concentration of stripping solution, type and acid concentration of the acidic solution, extractant and surfactant concentrations, phase ratio and treatment ratio were studied and optimum conditions were determined. The results showed that it is possible to extract 99% of chromium(VI) from the acidic solution containing Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) ions, at the optimum conditions. 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Behavior of damaged and undamaged concrete strengthened by carbon fiber composite sheets

Ilki, Alper,Kumbasar, Nahit Techno-Press 2002 Structural Engineering and Mechanics, An Int'l Jou Vol.13 No.1

Many existing concrete structures suffer from low quality of concrete and inadequate confinement reinforcement. These deficiencies cause low strength and ductility. Wrapping concrete by carbon fiber reinforced polymer (CFRP) composite sheets enhances compressive strength and deformability. In this study, the effects of the thickness of the CFRP composite wraps on the behavior of concrete are investigated experimentally. Both monotonic and repeated compressive loads are considered during the tests, which are carried out on strengthened undamaged specimens, as well as the specimens, which were tested and damaged priorly and strengthened after repairing. The experimental data shows that, external confinement of concrete by CFRP composite sheets improves both compressive strength and deformability of concrete significantly as a function of the thickness of the CFRP composite wraps around concrete. Empirical equations are also proposed for compressive strength and ultimate axial deformation of FRP composite wrapped concrete. Test results available in the literature, as well as the experimental results presented in this paper, are compared with the analytical results predicted by the proposed equations.

Low strength concrete members externally confined with FRP sheets

Ilki, Alper,Kumbasar, Nahit,Koc, Volkan Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.2

In this paper axial loading tests on low strength concrete members, which were confined with various thickness of carbon fiber reinforced polymer (CFRP) composite sheets are described. Totally 46 specimens with circular, square and rectangular cross-sections with unconfined concrete compressive strengths between 6 and 10 MPa were included in the test program. During the tests, a photogrammetrical deformation measurement technique was also used, as well as conventional measurement techniques. The contribution of external confinement with CFRP composite sheets to the compressive behavior of the specimens with low strength concrete is evaluated quantitatively, in terms of strength, longitudinal and lateral deformability and energy dissipation. The effects of width/depth ratios and the corner radius of the specimens with rectangular cross-section on the axial behavior were also examined. It was seen that the effectiveness of the external confinement with CFRP composite sheets is much more pronounced, when the unconfined concrete compressive strength is relatively lower. It was also found that the available analytical expressions proposed for normal or high strength concrete confined by CFRP sheets could not predict the strength and deformability of CFRP confined low strength concrete accurately. New expressions are proposed for the compressive strength and the ultimate axial strain of CFRP confined low strength concrete.

A trilinear stress-strain model for confined concrete

Ilki, Alper,Kumbasar, Nahit,Ozdemir, Pinar,Fukuta, Toshibumi Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.5

For reaching large inelastic deformations without a substantial loss in strength, the potential plastic hinge regions of the reinforced concrete structural members should be confined by adequate transverse reinforcement. Therefore, simple and realistic representation of confined concrete behaviour is needed for inelastic analysis of reinforced concrete structures. In this study, a trilinear stress-strain model is proposed for the axial behaviour of confined concrete. The model is based on experimental work that was carried out on nearly full size specimens. During the interpretation of experimental data, the buckling and strain hardening of the longitudinal reinforcement are also taken into account. The proposed model is used for predicting the stress-strain relationships of confined concrete specimens tested by other researchers. Although the proposed model is simpler than most of the available models, the comparisons between the predicted results and experimental data indicate that it can represent the stress-strain relationship of confined concrete quite realistically.

Extraction of Ni(II) from spent Cr–Ni electroplating bath solutions using LIX 63 and 2BDA as carriers by emulsion liquid membrane technique

Volkan Eyupoglu,Recep Ali Kumbasar 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

In the present study, the synergistic extraction of Ni(II) from spent Cr–Ni electroplating bath solutions(SEBS) was determined using 5,8-diethyl-7-hydroxydodecan-6-one oxime(LIX 63) and 2-bromodecanoicacid(2BDA) by emulsion liquid membranes(ELM)s. The effect of membrane and aqueous phaseproperties on Ni(II) transport was experimentally investigated. Ni(II) extraction was obtained to behigher than 98.5% in the optimum conditions within 6 min. The higher separation factor (bNi/Cr) wasobtained as 677. In addition, Ni(II) extraction kinetics depends on LIX63 because the extraction kineticsof LIX63 is slower than 2BDA. Therefore, we have determined that 2BDA acts as a synergist in presentextraction system.

Low strengh concrete members externally confined with FRP sheets

Alper Ilki,N. Kumbasar,Volkan Koc 국제구조공학회 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.2