• Resources Recycling
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• v.9 no.4
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• pp.3-15
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• 2000

Reduction of Electric Arc Furnace dust with carbon (graphite) was studied at the temperature range of $800^{\circ}C$ to $1100^{\circ}C$ in Ar gas atmosphere. The briquetted dust with graphite powder was heated in a vertical tube furnace for given reaction time and Quenched in Ar gas atmosphere. It was found that initially the reduction of Zn was chemically controlled and the activation energy was about 120 KJ/mole. Because the almost all of Pb was removed with Cl in the form of $PbCl_2$, it is considered that Pb is removed by chloride reduction. Cu was vaporized as a chloride up to 30% of its original content, but the remaining of Cu would be accumulated with the reduced iron. and also, Cd was removed completely within 15 min. at $1000^{\circ}C$.

• 한국전기화학회:학술대회논문집
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• 1999.10a
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• pp.55-55
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• 1999

• Polymer(Korea)
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• v.25 no.6
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• pp.826-832
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• 2001

In this study, PPy/gold/mylar type electroactive bi-layer actuator was prepared by the electrochemical polymerization of pyrrole onto the gold/mylar film and the actuation characteristics were studied using bending beam method. Conducting polymer-based actuators undergo volumetric changes due to the movement of dopant ions into the film during the electrical oxidation process. The bilayer films exhibited different actuation characteristics depending on dopant ion size. It was observed that the relatively small dopant ion (i.e. toluene sulfonate) moved into the PPy film at oxidized state, so volume expanded to result in bending motion. In case of the film having large dopant ion (i.e. dodecylbenzenesulfonate), volume expansion was observed at reduced state. This is due to the incorporation of $Na^+$ counterion with water molecules, while the large dopant ion was fixed in the film due to the limited mobility during tile redox process.

• Resources Recycling
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• v.27 no.2
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• pp.68-76
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• 2018

EAF (Electric arc furnace) dust is an important secondary resource such as zinc, lead, and iron. Recycling of EAF dust is benefit to solving disposal and environmental problems caused by the heavy metals entrained in the dust. In this study, pyrometallurgical treatment technology of EAF dust reviewed for the improvement of conventional process and development of new process. The existing technologies categorized into four groups: those by rotary kiln process, rotary hearth furnace (RHF) process, shaft type process, and reduction smelting process. The product of these processes are ZnO and Fe or slag as a waste. Their mechanisms for the production of ZnO from EAF dust were carbothermic reduction and oxidation of zinc gas with air.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.83-91
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• 1993

The eletrochemical behavior of light lanthanide complexes has been investigated by several electrochemical techniques in alkaline solutions. The composition of the complexes was determined by spectrophotometric method to be 1 : 1 and reduction mechanism was two steps 1 electron transfer reaction. The half wave potential of first peak depended on pH and cathodic current showed remarkably adsorptive properties. The results of DC and CV investigation demonstrated the quise-reversible nature of the electron transfer. The anion radical formed after first one electron reduction process, dimerizes to form dimer. The apparent irreversible behavior of the second wave is a result of the existence of a fast protonation following the second electron transfer. An exhaustive electrolysis was carried out at controlled potential of -1.80 V, deep blue color of the solution became progressively weaker, and then the solution became colorless solution. The final product of an exhaustive electrolysis is electro-inactive. The appearance of four steps may be explained by the fact the reduction of Ln-OCP elucidated ECEC mechanism.

• Journal of the Korean Electrochemical Society
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• v.14 no.2
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• pp.110-116
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• 2011

Ru black was used for cathode catalyst in polymer electrolyte membrane fuel cell which showed low performance at the initial test. However, it was observed that the performance of Ru black cathode was dramatically enhanced after certain kind of experiment compared with initial one. It might be due to an electrochemical treatment in which a voltage was applied to the Ru cathode for constant period time. When a constant potential of 0.1 V was applied to Ru cathode for 30 min, the fuel cell performance of Ru cathode showed the best results. In order to investigate the effect of electrochemical treatment on the performance enhancement, the characteristics of electrochemically treated Ru black was compared with that of Ru black which was reduced under $H_2$ atmosphere. From XRD results, it was turned out that Ru black was not completely converted to metallic Ru by electrochemical treatment, but it is sufficient to be one of reasons for the performance enhancement. According to the results of CO stripping voltammetry, it was observed that some Ru was removed from Ru electrode by electrochemical treatment which might have a bad effect on the fuel cell performance. The removal of some Ru from as-received Ru black by electrochemical treatment is also another reason for the enhancement of fuel cell performance.

• Journal of the Korean Chemical Society
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• v.37 no.8
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• pp.702-710
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• 1993

Electrochemical reduction of thionyl chloride has been carried out at glassy carbon and molybdenum electrodes, the surface of which is modified by binuclear tetradentate schiff base Co(II), Ni(II),Cu(II) and Fe(II) complexes. The catalyst molecules of transition metal(II) complexes were adsorbed on the electrode surface and reduced thionyl chloride resulting in a generation of oxidized catalyst molecules. There was an optimum concentration for each catalyst compound. The catalytic effects of SOCl$_2$ reduction were larger on glassy carbon electrodes compared to molybdenum electrodes and enhancements in reduction current of up to 120${\%}$ at the glassy carbon electrodes. The reduction currents of thionyl chloride were increased and the reduction potentials were shifted to the negative potential when scan rates became faster. The reduction of thionyl chloride was proceed to diffusion controlled reaction.

• Journal of the Mineralogical Society of Korea
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• v.18 no.1
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• pp.1-9
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• 2005

The electrocatalytic reduction of O₂ was investigated with methyl viologen and methylene blue incorporated clay-modified electrodes. Clay suspensions were prepared with Na-montmorillonite, Ca-montmorillonite, and kaolinite. The methyl viologen-clay modified electrodes were made by coating clay suspensions adsorbing methyl viologen on a glassy carbon electrode. Cyclic voltammetry were performed in aqueous media to investigate the electrocatalytic property of the modified electrode in reducing O₂. A Na-montmorillonite modified electrode showed the greatest adsorption capacity for methyl viologen. The modified electrode made of Na-montmorillonite suspension of 0.87 g/10 mL and a 2.5 mM of methyl viologen solution showed the most effective electrocatalytic property, where the catalytic reduction potential was shifted by 242.6 mV toward the positive potential. The electrocatalytic ability was more significant in acidic (pH=3.7) and alkaline (pH=12.7) media than the neutral pH range (6.3∼8.3). The methyl viologen-Na-montmorillonite modified electrode had the good reproducibility and maintain the electrocatalytic property over 20 times reuse.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.360-364
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• 2000

We studied the degree of rancidity of linoleic acid for the electrochemical redox reaction in time course and the kinetic parameters. The current of the linoleic acid was increased and the potential was shifted to the positive potential when scan rates were faster. The redox reaction of the linoleic acid was proceeding to totally irreversible and diffusion controlled reaction. From these results, diffusion coefficient(D$\_$o/) of linoleic acid was observed to 2.61$\times$10$\^$-6/ ㎠/s in the 0.1 M TEAP/DMF electrolyte solution. Also, exchange rate constant(K$\^$o/) was observed to 9.79$\times$10$\^$-11/ cm/s. The leaving time in air condition was found to affect the rancidity. We predicted that the product was carbonyl compounds.

• Analytical Science and Technology
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• v.9 no.2
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• pp.161-167
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• 1996

An investigation was made of possible ways in which one could control the relative rates of cadmium deposition and hydrogen evolution by binary additive systems. Benzyl alcohol was employed as an additives due to its ability to form a hydrophobic film which inhibit the electroreduction of water to form hydrogen. The second additive was chosen to make the cadmium(II) ion less hydrophilic and increase its ability to cross the hydrophobic benzyl alcohol film and be electrodeposited at the cathode. It was shown by voltammetric and current efficiency studies that ion pairing and complexing additives could be used to accelerate the reduction of cadmium in the presence of the benzyl alcohol film. It was also shown that the benzyl alcohol film lowered the dielectric constant of the solution near the electrode enough to obtain ion pairing between the sodium ion and the negative chloride complex of cadmium and accelerate the reduction of the cadmium. This acceleration did not occur in the sulfate solution in the absence of chloride since cadmium(II) is primarily present as a positive aquo complex and ion pairing, if it occured, would not accelerate but would hinder reduction of cadmium.