• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.05a
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• pp.86-89
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• 2006

전해 생성된 염소를 이용하여 구리를 침출하는 연구를 수행하였다. 염산농도 $1molL^{-1}$, 반응온도 $25^{\circ}C$, 교반속도 400rpm 조건에서 전류밀도 $10mA/cm^{2}$의 경우 반응온도에 상관없이 구리의 침출속도가 동일하였으나 $Cl_{2}$ 생성량이 충분한 $40mA/cm^{2}$의 경우 온도가 높을수록 구리의 침출속도가 증가하였다. 침출된 구리농도가 6g/L 부근에 도달하면 염소의 공급속도에 상관없이 구리의 침출이 둔화되었다. 이는 구리-염소 착화물의 형성과 관련된 것으로 생각된다.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.473-480
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• 1996

Synthesis of n-perfluorooctanesulfonyl fluoride(n-PFOSF), which is valuable precursor perfluoro-chemicals, was studied by electrochemical fluorination(ECF). Of prime concern was to investigate the cyclic voltamograms of Ni electrode in anhydrous hydrogen fluoride(AHF) with and without the reactants and to measure fluorine evolution potential. In a batch cell, chronoampherometric electrolysis and various chemical analysis such as GC, GC/MS and IR were used to understand the amphere change of electrode and the reaction paths. Fluorine equilibrium potential was found to be about 2.8V(vs. $Cu/CuF_2$) from the cyclic voltammograms and decay curves of anode potential in AHF. In batch processes, the ECF proceeded in two distinguished steps. The first step proceeded electrochemically and the second one chemically. Under 7V(vs. $Cu/CuF_2$), amount of crude products was proportional to the applied anode potential. Above 7V(vs. $Cu/CuF_2$), it had a hundred percentage with weight ratio of reactants and productivity of PFOSF was almost constant.

• Resources Recycling
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• v.22 no.6
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• pp.55-63
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• 2013

In this study, a electrochemical-chemical combined dissolution technology was conducted by electro-generated chlorine to obtain ruthenium solution from ruthenium metal. To find out the optimum leaching conditions of ruthenium in chloride solution, this leaching process was carried out on the variation of pH, reaction time, temperature and applied voltage at the electro-generated chlorine system in the reaction bath. Also, ozone generator was used to obtain ruthenium(III) chloride solution to increase the leaching rate. The optimum condition was observed at pH 10.0, $40^{\circ}C$ within 1 hr of reaction time that more than 88% of ruthenium(III) chloride dissolved.

• Resources Recycling
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• v.26 no.4
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• pp.88-94
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• 2017

The recovery of gold in cyclone type electrolytic cell was conducted from solution for stripping gold of PCB by cyanide. The electrolytic recovery behaviors of gold was investigated by reaction time and addition of electrolytic sodium hypochlorite (NaOCl) and gold plating additive (KG-120). Because the electrolysis generated NaOCl reacted with the cyanide in the leachate by alkaline chlorination, more than 99% of the cyanide was removed at a $NaOCl(g)/CN^-(g)$ ratio of 1.0. When NaOCl was added during the recovery of the gold from cyanide leachate in the cyclone electrolytic cell, the recovery of gold was 98% at the ratio of $NaOCl(g)/CN^-(g)$ from 0.5 to 2.5 in 480 minutes and decreased rapidly over the ratio of 3.0. Gold was recovered more than 99% by adding 1.5 and 4.5%(v/v) of KG-120 with NaOCl in 480 minutes. In particular, when the concentration of KG-120 was 3.5 and 4.5%(v/v), more than 96% of gold was recovered within 240 minutes and the initial recovery rate was relatively faster. The optimum concentration of KG-120 is 3.5%(v/v) considering the economic feasibility and efficiency.

• Resources Recycling
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• v.15 no.6 s.74
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• pp.33-40
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• 2006

Leaching behavior of copper using electro-generated chlorine was investigated in hydrochloric acid solutions. When leached copper concentration was lower than 3.6g/L, the utilization efficiency of the electro-generated chlorine was close to 100% at $10mA/cm^2,\;25^{\circ}C$, 400 rpm in 1M HCl solutions. The concentration ot the leached copper over 3.6g/L caused the electrode potential to drop quietly, leading to a change or leaching mechanism. The leaching rate oi copper began to decrease at the concentration of copper 5.2g/L. This is probably due to the formation of a layer of CuCl on Cu metal in 1M HCl solutions. The leaching rate, however, was not retarded in a solution ot high chloride concentration. The high solubility of CuCl in the solution may prevent the formation of CuCl on Cu metal.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.566-567
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• 2012

본 논문에서는 산성수를 전기분해하여 알칼리 이온수를 생성하는 정수 시스템을 제안하였다. 시스템은 크게 전해조, 냉각 유닛, 콤프레서, 정수?터 등으로 구성되어 있다. 특히 알칼리이온수를 생성하기 위해서는 전기분해를 위한 전력변환 회로가 필요하다. 본 논문에서는 알칼리이온수기를 위한 전해조 구동회로를 PSIM을 통한 검증 하였다.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1192-1199
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• 1999

The morphology changes of cadmium hydroxide into ${\gamma}$ phase by eletrolytes were carried out to improve the high rate charge and discharge efficiency of pasted cadmium electrodes. KOH solutions with different concentrations of NaOH were used as eletrolytes. It was found that the utilization of active material of cadmium electrode was the best in an electrolyte with 1.82 M NaOH. The amount of ${\gamma}-Cd(OH)_2$ increased in proportion to the concentration of NaOH. The surface area measurement showed that an active material which contained mainly ${\gamma}-Cd(OH)_2$ had a higher specific surface area than an active material of ${\beta}-Cd(OH)_2$. In a sealed cell, the discharge capacity was improved at high rate charge and discharge (1.0 C, 2.0 C) by using an electrolyte with NaOH. Furthermore, these improved performances were maintained up to 500 cycles at 1.0 C rate charge and discharge cycles.

• Proceedings of the Petrological Society of Korea Conference
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• 2009.05a
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• pp.132-134
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• 2009

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.109-110
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• 2015

알루미늄 합금의 종류중 하나인 ADC12는 가공성이 좋고 가격이 저렴하기 때문에 산업의 많은 분야에 이용할 수 있지만 양극산화를 진행할 시 합금의 주요 구성성분인 실리콘(Si)으로 인해 균열(Crack)이 생기는 문제가 발생하여 이에 따라 균일한 산화막이 생성되지 않다는 단점을 가지고 있다. 이 단점을 극복하기 위해 양극산화를 진행할 때 금속 음이온 성분이 첨가된 전해질을 이용하면 실리콘이 떨어져 나간 부분을 자가치료(Self-healing)할 수 있어 피막의 경도를 포함한 각종 특성이 증가하는 결과를 확인할 수 있다. 본 연구에서는 ADC12를 양극산화할 때 황산 수용액을 기본 전해질로 하여 전해질에 타이타늄(Ti), 마그네슘(Mg), 몰리브덴(Mo)이 포함되어 있는 금속 음이온 물질을 첨가하였고, 금속 음이온 전해질의 농도와 양극산화 진행 시간을 변수로 하여 제조한 산화막의 전기화학적 특성을 SEM(Scanning Electron Microscope), Tafel plot, 그리고 Microvickers hardness tester를 통해 평가하였다.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.352-359
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• 2005

This work has studied the changes of pH in both of anodic and cathodic chambers of a divided cell due to the electrolytic split of water during the ammonia decomposition to nitrogen, and has studied the continuous decomposition characteristics of ammonia in a multi-cell stacked electrolyzer. The electrolytic decomposition of ammonia was much affected by the change of pH of ammonia solution which was caused by the water split reactions. The water split reaction occurred at pH of less than 8 in the anodic chamber with producing proton ions, and occurred at pH of more than 11 in the cathodic chamber with producing hydroxyl ions. The pH of the anodic chamber using an anion exchange membrane was sustained to be higher than that using a cation exchange membrane, which resulted in the higher decomposition of ammonia in the anodic chamber. By using the electrolytic characteristics of the divided cell, a continuous electrolyzer with a self-pH adjustment function was newly devised, where a portion of the ammonia solution from a pHadjustment tank was circulated through the cathodic chambers of the electrolyzer. It enhanced the pH of the ammonia solution fed from the pH-adjustment tank into the anodic chambers of the electrolyzer, which caused a higher decomposition yield of ammonia. And then, based on the electrolyzer, a salt-free ammonia decomposition process was suggested. In that process, ammonia solution could be continuously decomposed into the environmentally-harmless nitrogen gas up to 83％, when chloride ion was added into the ammonia solution.