Seongnam, South Korea
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Park H.-S.,Yonsei University | Park S.S.,LS Nikko Copper Inc | Sohn I.,Yonsei University
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science | Year: 2011

Understanding the viscous behavior of copper smelting slags is essential in increasing the process efficiency and obtaining the discrete separation between the matte and the slag. The viscosity of the FeOt-SiO 2-Al2O3 copper smelting slags was measured in the current study using the rotating spindle method. The viscosity at a fixed Al2O3 concentration decreased with increasing Fe/SiO 2 ratio because of the depolymerization of the molten slag by the networkmodifying free oxygen ions (O2-) supplied by FeO. The Fourier transform infrared (FTIR) analyses of the slag samples with increasing Fe/SiO2 ratio revealed that the amount of large silicate sheets decreased, whereas the amount of simpler silicate structures increased. Al 2O3 additions to the ternary FeOt-SiO 2-Al2O3 slag system at a fixed Fe/SiO 2 ratio showed a characteristic V-shaped pattern, where initial additions decreased the viscosity, reached a minimum, and increased subsequently with higher Al2O3 content. The effect of Al 2O3 was considered to be related to the amphoteric behavior of Al2O3, where Al2O3 initially behaves as a basic oxide and changes to an acidic oxide with variation in slag composition. Furthermore, Al2O3 additions also resulted in the high temperature phase change between fayalite/hercynite and the modification of the liquidus temperature with Al2O3 additions affecting the viscosity of the copper smelting slag. © The Minerals Metals & Materials Society and ASM International 2011.

Batchu N.K.,Mokpo National University | Sonu C.H.,LS Nikko Copper Inc. | Lee M.S.,Mokpo National University
Hydrometallurgy | Year: 2013

The solvent extraction of manganese(II) has been studied from chloride solutions using a mixture of Cyanex 272 and Cyanex 301 dissolved in kerosene. The mixture has shown a significant synergistic effect at XCyanex 272 = 0.6. The synergistic enhancement factor was calculated to be 14. The extracted species in the organic phase was found to be MnH2A 2B2 using slope analysis method. Stripping experiments showed that manganese could be recovered using dilute sulphuric acid solutions from the loaded mixture. The mixture has a potential for the separation of Mn(II) from other associated metals. © 2013 Elsevier B.V.

Park S.-I.,LS Nikko Copper Inc. | Kwak I.S.,Engineering R and nter | Won S.W.,Chonbuk National University | Yun Y.-S.,Chonbuk National University
Journal of Hazardous Materials | Year: 2013

Glutaraldehyde (GA)-crosslinked chitosan beads (GA-CS) are prepared with coagulating solution containing sodium tripolyphosphate and GA, and used for the adsorption of metals from binary-metal solution Au(III) and Pd(II). GA-CS exhibited selective sorption of Au(III) in the Au(III)-Pd(II) mixture. X-ray diffraction analyses showed that Au(III) was reduced to Au(0) following sorption, while Pd(II) was present as unreduced divalent form. Increased GA led to more selectivity toward Au(III), indicating that Au(III) selectivity is attributed to reduction-couple sorption of Au(III) with a reducing agent GA. Furthermore, a 2-step desorption process enabled selective recovery of Pd and Au using 5. M HCl and 0.5. M thiourea-1. M HCl, respectively, leading to pure Pd(II) and Au(III)-enriched solutions. This finding may open a new way to design reduction-coupled selectivity-tunable metal sorbents by combination of redox potentials of metal ions and reducing agents. © 2013 Elsevier B.V.

Kumar B.N.,Mokpo National University | Sonu C.H.,LS Nikko Copper Inc. | Lee M.S.,Mokpo National University
Journal of Chemical and Engineering Data | Year: 2013

Synergistic solvent extraction of manganese(II) using a mixture of Cyanex 272 and Cyanex 301 from chloride solutions has been studied in the view of developing a chemical model. Slope analysis method was used for the determination of extraction stoichiometry. The equilibrium constant for the synergistic solvent extraction reaction was calculated by taking into account of the complex formation reactions between Mn(II) and chloride ions. The activity coefficients of species in the aqueous phase were estimated by applying the Bromley equation. The calculated distribution ratios of Mn(II) agreed well with the experimentally measured values. © 2013 American Chemical Society.

Batchu N.K.,Mokpo National University | Sonu C.H.,LS Nikko Copper Inc. | Lee M.S.,Mokpo National University
Hydrometallurgy | Year: 2014

Studies on solvent extraction equilibrium of Mn(II) from sulfuric acid solutions with a mixture of Cyanex 301 and TBP have been carried out. The extraction of Mn(II) by Cyanex 301 was enhanced significantly by the addition of TBP at a Cyanex 301 mole fraction of 0.6 and the synergistic coefficient calculated was 1.16. Synergistic extraction reaction was identified on the basis of slope analysis and extracted species was proposed to be MnA2 · TBP. The solvent extraction equilibrium constant was estimated from the extraction data by considering the formation of complexes and activity coefficients of metal species in the aqueous phase. There was a good agreement between calculated distribution ratios of Mn(II) and experimentally measured values. © 2014 Elsevier B.V.

Kim E.,Pennsylvania State University | Kim E.,LS Nikko Copper Inc. | Osseo-Asare K.,Pennsylvania State University
Hydrometallurgy | Year: 2012

Potential vs. pH diagrams for the systems Fe-Si-(Cl -)-(F -)-H 2O were generated using the HSC5.0 software and applied to purification of metallurgical-grade silicon (MG-Si) by hydrometallurgical methods. The diagrams for the Fe-Si-H 2O system show that with increasing electrochemical potential (Eh) the order of appearance of Fe silicides is FeSi 2, FeSi, and Fe 3Si. Further, from a thermodynamic standpoint, Si in the Fe silicides (FeSi 2, FeSi, and Fe 3Si) would be easier to oxidize than Fe, due to the lower potentials of the corresponding silicides, compared with Fe. The early formation of SiO 2 during dissolution may prohibit or retard further dissolution of Fe, as verified by previous experimental results. This inhibitive effect is expected to increase with increasing Si content in the silicides. The diagrams for the Fe-Si-Cl --H 2O system indicate that dissolution of Fe silicides with relatively low Si content, such as FeSi and Fe 3Si, is enhanced by adding chloride ions to acidic solutions. In the presence of HF, formation of fluoro-complexes enlarges the stability domains of dissolved iron and silicon, which increase with increasing {F} and/or decreasing temperature. The trends obtained for the Fe-Si-F --H 2O system suggest that the dissolution of Fe silicides would be enhanced by decreasing temperature or removing FeF 2(s) (e.g.; via ultrasonication) during the leaching process.

An apparatus for inspecting an electrolytically refined metal deposition plate includes a loading robot for loading the metal deposition plate to the inspection unit; an unloading robot for unloading the metal deposition plate upon which inspection has been completed by the inspection unit; a conveyor unit for conveying the metal deposition plate unloaded by the unloading robot; and a controller for grading the metal deposition plate based on a size of and distribution per unit surface area of nodules on the metal deposition plate using images of the metal deposition plate captured by the inspection unit.

Hyundai Motor Company and Ls Nikko Copper Inc. | Date: 2010-08-31

Featured is a refrigerant injection device which is particularly suitable for use in a refrigerant destruction facility using an incinerator. Such an injection device includes a storage device which stores the refrigerant and a decompressor fluidly coupled to the storage device. The injection device further includes two flow meters and a cutoff-valve that are fluidly coupled to the decompressor. The cutoff valve is configured to cut off the injection of refrigerant. The injection device further includes bypass flow members that are fluidly coupled to the two flow meters. The bypass flow members and flow meters are configured and arranged to selectively measure the flow rate and to perform flow meter calibration without stopping the feeding of refrigerant to the injection device.

Valuable metals such as cobalt, nickel, manganese, and lithium can be economically recovered from various lithium secondary battery-related wastes by the inventive method which comprises liquid-phase leaching a scrap powder containing Co, Ni, Mn, and Li, and purifying and solvent-extracting the resulting leaching solution to recover each of said Co, Ni, Mn, and Li, wherein the liquid-phase leaching is performed by a two-step counter-current leaching using an inorganic acid solution or a mixed solution of an inorganic acid and hydrogen peroxide.

Nguyen T.H.,Mokpo National University | Sonu C.H.,LS Nikko Copper Inc. | Lee M.S.,Mokpo National University
Hydrometallurgy | Year: 2016

A new process for complete separation of Pd(II), Pt(IV), Ir(IV) and Rh(III) from concentrated hydrochloric acid solutions was proposed by employing solvent extraction. In the HCl concentration range from 1 to 6 M, only Pd(II) was extracted by LIX 63 and the Pd(II) in the loaded LIX 63 was stripped by thiourea. Extraction of the Pd(II) free raffinate with TBP at 6 M HCl solution led to selective extraction of Pt(IV) over iridium and Rh(III) and stripping of the loaded TBP with dilute HCl solution resulted in pure Pt(IV) solution. The extraction of iridium by TBP and Aliquat 336 indicated the possibility of Ir(IV)'s reduction to Ir(III) during the extraction with LIX 63. After adding NaClO3 as an oxidizing agent to the Pd(II) and Pt(IV) free raffinate, extraction of the resulting solution with Aliquat 336 led to selective extraction of Ir(IV) over Rh(III). Use of HClO4 solution could strip the Ir(IV) from the loaded Aliquat 336. This process can be utilized for the recovery of the four PGMs with high purity from diverse resources. © 2016 Elsevier B.V.

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