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Recovery of Acids and Metals from a Spent Pickling Liquor through Ion Exchange and Cementation
Lee, Kisay,Lee, Inkyoo 한국공업화학회 2004 Journal of Industrial and Engineering Chemistry Vol.10 No.2
A process scheme is suggested for the treatment of a metal-containing spent pickling liquor, with the purposes of possible acid recovery and metal separation. Use of anion exchange, followed by packed-bed cementation, was studied for the treatment of a model wastewater containing HNO₃, HF, Fe^(2+), and Ni^(2+). Acids and metal ions were separated through a Dowex 1-X8 anion exchanger of the C1-form, and the sorbed acids were recovered by regenerating the exchanger with HCl. The obtained Fe-Ni mixture (Fe^(2+): 3 g/L Ni^(2+): 1.3 g/L; 1 L) went through a continuous cementation process using an iron-packed bed (40 g iron in a 14-mm-diameter column), where Ni^(2+) was reductively deposited onto iron and the Fe^(2+) concentration increased in an aqueous stream. In a recycled closed-loop cementation system, 99.8% of the nickel was removed from the mixture solution (from 1.3 g/L to 2 ㎎/L) and the aqueous Fe^(2+) concentration was increased more than 10-fold (from 3 g/L to 34 g/L) during a 13 BV passage.
Operating Parameters for Glutamic Acid Crystallization in Displacement Ion Exchange Chromatography
Lee, Kisay The Korean Society for Biotechnology and Bioengine 1997 Biotechnology and Bioprocess Engineering Vol.2 No.2
Glutamic acid can be crystallized inside cation exchange column when displacer NaOH concentration is high enough to concentrate displaced glutamic acid beyond its solubility limit. Resulting crystal layer of glutamic acid was moved with liquid phase through the column, and thus could be eluted from the column and recovered in fraction collector. For the purpose of enhancing crystal recovery, effects of operating parameters on the crystal formation were investigated. The increase in the degree of crosslinking of resin favored crystal recovery because of its low degree of swelling. Higher concentration of displacer NaOH was advantageous. If NaOH concentration is too high, however, crystal recovery was lowered due to the solubility-enhancing effects of high pH and ionic strength. The decrease of mobile phase flow rate enhanced crystal recovery because enough time to attain local equilibrium could be provided, but film diffusion would control the overall crystal formation with extremely low flow rate. Lower temperature reduced solubility of glutamic acid and thus favored crystal formation unless the rate of ion exchange was severely reduced. The ion exchange operated by displacement mode coupled with crystallization was advantageous in reducing the burden of further purification steps and in preventing purity-loss resulted from overlapping between adjacent bands.
Lee, Kisay 한국화학공학회 1996 Korean Journal of Chemical Engineering Vol.13 No.2
A simple mathematical method for the analysis of multicomponent displacement development was developed. Calculations in this method utilizes the information residing in the isotactic condition which is established after the full development of solute propagation occurring in the chromatographic separation operated by the mode of displacement development. Transient shock wave velocities and concentration changes are determined based upon the equilibrium theory of chromatography and the basic rules required in constructing the (t,z)-diagram of solute propagation along the column. Calculations involve solving simple algebraic equations to predict the transient behaviors of propagating solutes inside the column, the elution profiles of final products, and the minimum column length required for the complete separation.
Lee, Kisay 한국화학공학회 1996 NICE Vol.14 No.3
A simple mathematical method for the analysis of multicomponent displacement development was developed. Calculations in this method utilizes the information residing in the isotactic condition which is established after the full development of solute propagation occurring in the chromatographic separation operated by the mode of displacement development. Transient shock Nave velocities and concentration changes are determined based upon the equilibrium theory of chromatography and the basic rules required in constructing the (t,z)-diagram of solute propagation along the column. Calculations involve solving simple algebraic equations to predict the transient behaviors of propagating solutes inside the column, the elution profiles of final products, and the minimum column length required for the complete separation.
An Analysis of Multicomponent Separation by Displacement Chromatography
Lee,Kisay 明知大學校 産業技術硏究所 1995 産業技術硏究所論文集 Vol.14 No.-
A general theory for the multicomponent chromatography was extended to the ideal displacement chromatography(DPC) system expressed with constant separation factors and mole fractions. A procedure of numerical calculation to simulate final band profiles were presented and the effects of feed and displacer compositions on the election band profiles were discussed in the case of cation exchange chromatography. When the feed mixture and displacer contain no presaturant component, the eluting bands are pure and the band durations are proportional to the corresponding mole fractions in the initial feed mixture. As the fraction of presaturant increases in the displacer solution, the purity of final products is lowered and the band widths are broadened.