Earticle

본 연구는 건설공사를 시공하기 전에 투입되는 자재, 노무, 장비의 정보를 판단할 수 있는 과학적인 근거와 절차를 통하여 의사 결정할 수 있는 효율적인 생산성 정보를 지원할 수 있는 도구를 마련하고자 한다. 공동주택 시멘트 액체방수 공사는 욕실, 발코니, 지하실 등에 많이 이용하는 방수공법이다. 그리고 공동주택에서는 세대별로 평면형태와 구조가 반복적이고, 작업의 특성상 인력에 의존하여 작업을 수행하고 있다. 또한 공동주택의 시멘트 액체방수 공사는 시공전에 투입되는 장비, 인력의 이용시간과 생산성을 예측하기 위하여 작업자의 경험과 과거의 실적자료에 의하여 생산성을 판단하고 있다. 하지만 현장 여건을 고려하지 못하고, 주관적인 판단에 의하여 공사 정보를 예측하고 있다. 따라서 본 연구에서는 공동주택 욕실부분 시멘트 액체방수 공사의 Cyclone 기법을 활용한 공동주택 시멘트 액체방수 공사의 생산성을 분석함으로써 공사현장에 합리적인 생산성 정보를 예측하고 지원할 수 있는 도구로서 활용 될 수 있을 것으로 판단된다.

This study aims to prepare the tool to support efficient productivity information that allows to make decisions through scientific grounds and procedure that can judge the information of materials, labor, and equipment inputted before the start of construction work. The cement liquid waterproofing construction of apartment house is a waterproofing method that is frequently used for bathrooms, balcony, basement, and so on. In addition, apartment houses have repeated shape of plane surface and structure by household, and the work is conducted relying on the manpower for the characteristic of work. Moreover, in the cement liquid waterproofing construction of apartment houses, the productivity is judged by the experiences of workers and the data of past results in order to predict the equipments inputted, hours of use of manpower, and productivity before starting construction. However, the conditions in the field fail to be considered, and the construction information is estimated by subjective judgment. Therefore, it is judged that this study can be utilized as the tool to predict and support the reasonable productivity information to the field of construction by analyzing the productivity of cement liquid waterproofing construction of apartment houses utilizing the cyclone technique of cement liquid waterproofing construction of bathrooms of apartment houses.

This study was performed to identify the accurate exercise prescription methods by investigating how moderate to high intense exercise prescriptions through using treadmill stress test affect the differences of physical responds according to exercise types(treadmill, bike, stepper, cyclone). We selected 31 students of K university who does not exercise regularly more than 6 month. We measured maximum heart rate (MHR), maximum blood pressure (MBP) and VO2max and maximum rate pressure product (MRPP) through treadmill stress test, indentified Karvonen’s target heart rate (THR). Subjects performed Treadmill, Bike, Cyclone and Stepper 12 times at different day according to target heart rate (60%, 70%, 85%) and blood pressure, RPP and Rating of Perceived Exertion (RPE) were measured. Subjects arrived at target heart rate in 10 minutes after beginning exercise, and THR remained for 10 minutes. All measurements were done 2 minutes before closing. Statistically significant level was p<.05. In results, there were high RPP caused by increased systolic blood pressure (SBP) in Bike and RPE was similar in every exercise but local pain and fatigue of femoris muscle were high in bike and stepper of 70% and 80% intensity. Also RPP of 85% intensity was 90.1% of max RPP in treadmill stress test. The setting of exercise intensity – 85% of THR – from treadmill test is fair to treadmill, stepper, cyclone but must be considered about applying to bike. Stepper might be stressful femoris muscle thus must be used carefully to people with weak muscle strength in lower extremities.

In this study, to control exhausting emission gas from meat cooking, it was surveyed at the restaurant to get the hang of characteristics. The experimental study was conducted to control exhausting emission gas from meat cooking restaurants. The target pollutants were oil vapor, oil mist, oil droplet and fine particles. The control units were composed of cooling effect and condensing unit, cyclone unit, electrostatic precipitator unit and grease filter unit. And, the control efficiency was conducted. It was showed that particle size distribution was 0.23~5 ㎛ and median diameter was 2~2.5 ㎛. In this paper, the recent updates including the emission characteristics and control efficiency will be reported.

Recently, imported bituminous coals used in coal-fired power plants are pulverized into finer particles in order to increase combustion efficiency. So it is difficult to obtain high grade ash. But in some plants, coarse particles are produced by cyclone reject during the classification process of fly ash. Therefore in this study, production possibilities of high grade ash were confirmed by performing an experiment using conductive induction with cyclone reject. As a result, below 1% LOI with above 80% recovery high grade ash was obtained, but in the case of unburned carbon there was a difficulty during separation due to fine particle ash inside the unburned carbon. These facts were verified by SEM microscope photographs and EDS analysis.

A large amount of cesium-contaminated soil was generated as a result of the decontamination work following the accident at the Fukushima Daiichi Nuclear Power Plant. To reduce the final disposal volume of contaminated soil, it is necessary to separate the contaminated soil into low- and high-dose soil components and reuse the low-dose soil under 8000 Bq/kg. We have investigated a magnetic separation technique to reduce the volume of the contaminated soil. Magnetic separation is a volume reduction technology that utilizes these differences in magnetic properties. However, the high-gradient magnetic separation technique (HGMS) we have been studied has problems such as clogging of filters and low separation accuracy due to the passage of 2:1 type clay minerals with small particle diameters. In this study, we propose a new separation method using a cyclone-type magnetic separator that focuses not only on magnetic susceptibility but also on differences in particle size. The cyclone-type magnetic separator can separate 2:1 type clay minerals from 1:1 type clay minerals by inducing 1:1 type clay minerals with large particle diameters to the outside of the cylinder and 2:1 type clay minerals with small and large particle diameters to the inside of the cylinder through the difference in the combined magnetic and centrifugal forces acting on soil particles. Separation accuracy was evaluated using simulated soil consisting of vermiculite and kaolinite. Based on these results, the reduction rate of the radioactivity concentration was estimated, and the design guidelines of the device for practical use were discussed.

This study aims develope a Cyclone Simulation Expert System for the formworks. CYCLONE System is helpful for saving cost and time when planning constructions. But it is used only for education not for the real construction project. It is difficult for construction planners to apply CYCLONE to project. This study will help formwork planners to generate and use CYCLONE System without deep knowledge of it. Planners can generate CYCLONE Syntex just inputting several construction conditions.

In this study, two types of cyclone separators containing a structure of prevention underflow and a cyclone separator without the structure were analyzed by computational fluid technique. The pressure loss was increased by increasing the inlet velocity from 8m/s to 28m/s, and the velocity and pressure were compared through five cross sections in the vortex finder. Also, the velocity and the pressure contour in the central section were compared. It can be seen that the performance reduction of the cyclone separator by the prevention structure is related to the distance to the vortex finder inlet rather than the effect of the diameter of the structure.

티오요소와 염산 혼합 용액 중 은(Ag)을 금속으로 회수하기 위해 사이클론 전해법을 이용하였다. 유속, 전류밀도, 은 농도, 티오요소 농도, 염산 농도를 주요 변수로 하여 은의 전해회수 거동을 살펴보았다. 유속, 전류밀도와 염산 농도가 증가할수록 은의 회수속도가 증가하였으며, 은 농도가 증가함에 따라 은의 회수 속도는 감소하였고, 티오요소 농도는 은 회수율과 전류효율에는 큰 영향이 없었다. 유속 12 L/min., 전류밀도 0.75 A/dm 2 , 1 g/L Ag, 0.5 M Thiourea, 0.1 M HCl에서 실험하였을 경우 99% 이상의 은 회수율을 보였다. 대부분의 실험 조건에서 은(Ag)은 분말 형태로 회수되었다.

A cyclone type electrolytic method was used to recover silver from thiourea-hydrochloric acid mixed solutions. The electrowinning behavior of silver was investigated in different systems, such as the flow rate, current density, silver concentration, thiourea concentration and hydrochloric acid concentration. As the increase of the flow rate, current density and hydrochloric acid concentration, the recovery rate of silver was increased. Whereas, as the increase of silver concentration, the recovery rate of silver was decreased. The thiourea concentration did not affect the Ag recovery and current efficiency. Above 99% of Ag was recovered at the flow rate of 12 L/min., current density of 0.75 A/dm 2 , silver concentration of 1.0 g/L, 0.5 M thiourea and 0.1 M hydrochloric acid. In most experimental conditions, silver was recovered as a powder form.

This research was conducted for dewatered sludge cake of industrial wastewater treatment, i.e., as the object of inorganic sludge discharged especially in iron & steel manufacturing shop which used Air drying system to reduce water content. That drying system's single-type cyclone separator was confirmed to have significantly lower separation efficiency on the conditions 20μm and below of particular size through computational fluid dynamics(CFD) analysis. However, we found out the primarily advanced value of separation efficiency on dual-type directly connected. Regarding separation efficiency on size of 10μm, the efficiency of a single-type was presented at 51.91%. On the other side, the efficiency of the dual-type was 97.88%. This advanced effect of the dual cyclone separator was checked at a demo facility of air drying equipment designed by 340m3/min of airflow on site.

본 연구에서는 먼저 백금의 기본적인 전기화학 특성을 이해하고자 회전원반전극을 제조하여 회전수와 용액의 온도를 변화시켜가며 각각의 환원분극거동에 대한 연구를 수행하였다. 또한, 사이클론을 전해채취 공정의 전해조로 적용하여 백금의 전해채취 거동을 조사하였고 이를 위해 전해조에 인가되는 셀 전압, 전해조로 유입되는 용액의 유속과 pH 등을 변수로 하여 실험을 수행하고 각각의 경우에 대한 회수거동의 변화와 특징에 대해 연구를 수행하였다. Levich 식으로부터 계산한 백금의 확산 계수는 3.25×10-6cm2/s 이었으며 백금 전착에 필요한 활성화 에너지 값은 9.88kJ/mol의 값을 얻었다. 위의 결과로부터 백금이 환원되는 환원반응은 확산에 의해 반응속도가 지배되는 확산율속 반응임을 확인할 수 있다. 사이클론 전해조를 사용하여 백금의 전해채취 실험을 수행한 결과 유속과 인가전압이 증가함에 따라 회수율이 증가하였으며 Sherwood number(Sh)와 Reynolds number(Re)와의 관계식을 log-log 항으로 plot하여 나타낸 결과, Sh가 Re의 약 0.75의 값을 갖는 지수승에 비례하는 것을 알 수 있어 사이클론 전해조내의 유체흐름이 난류임을 알 수 있었다. 위의 실험 결과를 실제 석유화학 플랜트에서 폐기물로 배출되는 폐촉매로부터의 회수공정에 적용하여 본 결과 시약급 시료를 이용하여 제조한 용액에서의 회수거동과 거의 유사한 회수경향을 나타내었으며 99.9% 이상의 높은 순도를 가진 백금을 얻을 수 있었다.

In the present study, the electrochemical properties of Pt were investigated by cathodic polarization curves with a variation of rotation speed and solution temperature using rotating disk electrode. Using a cyclone electrowinning experiments were conducted with a variation of cell voltage, flow rate at inlet and pH and carried out researches for characteristics of each cases. The diffusion coefficient of Pt calculated from the Levich's equation was 3.25×10-6cm2/s and activation energy of Pt was 9.88kJ/mol, indicating that the deposition reaction of Pt was controlled by diffusion of Pt ions to the cathode. Reynolds number(Re) was proportional to Sherwood number(Sh)0.75. It shows that the flow in cyclone reactor is turbulent flow because the exponent of Sh term is larger than 0.33 which indicates laminar flow. The purity of Pt electrowon from the leach liquor was at least 99.9%.

염산 용액에서 주석을 금속으로 회수하기 위하여 사이클론 전해채취 방식을 사용하였다. 주석의 전해채취에 미치는 영향을 고찰 하기 위하여 유속, 전류밀도, 전해액 중 주석 농도, 염산 농도 영향에 대하여 조사하였다. 유속이 증가하고, 주석과 염산의 농도가 감소할수록 주석의 회수율과 전류효율이 증가하였고, 전류밀도가 증가함에 따라 회수율은 증가하였으나 전류효율은 감소하였다. 유 속 18 L/min., 3 A/dm 2 , 2.5 g/L Sn, 5 wt.% HCl 조건에서 효과적으로 주석을 회수할 수 있다.

Cyclone electrowinning method was used to recover tin to metal in hydrochloric acid solution. The effects of flow rate, current density, tin concentration, and hydrochloric acid concentration on the electrowinning of tin were investigated. As the flow rate increased and the concentration of tin and hydrochloric acid decreased, the tin recovery and current efficiency increased. As the current density increased, the recovery rate increased but the current efficiency decreased. Tin can be effectively recovered at flow rates of 18 L/min., 3 A/dm 2 , 2.5 g/L Sn, and 5 wt.% HCl.

This study aims to optimize the SDC (Spinning Dust Collector) system in amphibious assault vehicle engines through numerical analysis of dust and moisture particle separation efficiency using CFD-DPM. Focusing on an axial cyclone structure, the research evaluates separation efficiency across various particle sizes and flow conditions. The results demonstrate that vortices generated by cyclone blades play a critical role in influencing particle trajectories and improving separation performance. Additionally, the study highlights the significant impact of engine flow conditions and housing design, emphasizing that their careful optimization enhances the system's efficiency in separating dust and water. These findings offer valuable insights into optimizing inlet and outlet flow paths and cyclone housing design, providing a solid foundation for advancing SDC system performance in high-efficiency engines.

개조된 사이클론식 전해조를 사용하여 황산염 용액으로부터 금속 주석으로 회수하기 위하여 주석의 전해채취 거동을 조사하였다. 실험 변수로는 유속의 영향, 전류밀도, 전해질 용액의 황산 농도 및 주석 농도 등에 대하여 실시하였다. 실험 결과 100µm이하 크기의 분말상 금속 주석을 얻을 수 있었다. 유속 및 전류밀도 그리고 전해액중 황산농도가 증가할수록 주석의 석출율 및 전류효율값이 증가하였다. 그러나 주석의 농도가 감소함에 따라 주석의 석출율은 증가하나, 전류효율값은 감소하였다.

A electrodeposion behavior of tin was tested to recovery of tin metal from sulfate solution using a newly designed cyclone type electrolyzer. Parameters, such as flow rate, current density, tin and sulfuric acid concentration in the electrolyte were investigated. From the experimental results, a powered tin metal below 100 μm can be obtained. As the increase of flow rate, current density and sulfuric acid concentration in the electrolyte, electrodeposition ratio of tin and current efficiency were increased. The electrodeposition ratio of tin was increased with the decrease of tin concentration in the electrolyte, but the current efficiency was decreased.

플라스틱은 아주 유용한 물질로서 우리 일상생활에 폭넓게 이용되고 있다. 국내에서는 약 400 만톤의 폐플라스틱이 발생되고 있지만 재활용율은 30% 이하로 대부분 소각이나 매립에 의해 처리되고 있다. 따라서 폐플라스틱을 재활용할 수 있는 재질분리 기술개발 필요한 실정이다. 본 연구에서는 폐플라스틱 종말품으로부터 PET 회수를 위한 마찰하전 정전선별이 수행되었다. 하전특성 연구결과에 의하면, PET와 PVC의 하전극성과 하전량은 HDPE와 PP의 하전물질 그리고 상대습도가 낮을수록 효과적이었다. HDPE 싸이클론 하전장치를 이용한 재질분리 실험결과, PET의 품위와 회수율은 전극전압 30 kV 이상, 분리대위치 -2cm의 조건에서 각각 96.8%와 85.0%로 얻어졌으며, 분리대의 위치(-6cm)에 따라 PET 회수율이 24% 감소하지만 품위를 98.5%까지 분리할 수 있는 기술을 개발하였다.

Plastics are widely used in everyday life as very useful material. In Korea, about 4 million tons of plastic wastes are generated annually. However, recycling ratio is below 30%, and most of plastic wastes are disposed by landfill and incineration. Hence, the development of material separation technique that can recycle plastic wastes is a necessary situation. In this study, Triboelectrostatic separation for recovery of PET from final plastic wastes obtained from the sink product after wet-type gravity separation has been carried out. In the charging properties, the charge polarity and charge density of PET and PVC were very effective with the tirbo-charger made of PP and HDPE with the decrease in relative humidity. In material separation using HDPE cyclone charger, a PET grade of 96.80% and a recovery of 85.0% were achieved at 30 kV and the splitter position -2cm from the center. In order to obtain PET grade of 98.5%, PET recovery should be sacrificed by 24% with moving the splitter from the center to -6cm position.

본 연구에서는 먼저 팔라듐의 기본적인 전기화학 특성을 이해하고자 회전원반전극을 제조하여 회전수와 용액의 온도를 변화시켜가며 각각의 환원분극거동에 대해 연구를 수행하였다. 또한, 사이클론을 전해채취 공정의 전해조로 적용하여 팔라듐의 전해채취 거동을 조사하였고 이를 위해 전해조에 인가되는 셀 전압, 전해조로 유입되는 용액의 유속과 pH 등을 변수로 하여 실험을 수행하고 각각의 경우에 대한 회수거동의 변화와 특징에 대해 연구를 수행하였다. Levich 식으로부터 계산한 팔라듐의 확산 계수는 8.96 × 10-6 cm2 s-1 이었으며 팔라듐 전착에 필요한 활성화 에너지 값은 12.22 kJ mol-1의 값을 얻었다. 위의 결과로부터 팔라듐이 환원되는 환원반응은 확산에 의해 반응속도가 지배되는 확산율속 반응임을 확인할 수 있었다. 사이클론 전해조를 사용하여 팔라듐의 전해채취 실험을 수행한 결과 유속과 인가전압이 증가함에 따라 회수율이 증가하였으며 Sh와 Re와의 관계식을 log-log 항으로 plot 하여 나타낸 결과, 기울기는 Re의 지수항을 나타내며 팔라듐의 경우에는 Sh가 Re의 약 0.76의 값을 갖는 지수승에 비례하는 것을 알 수 있었다. 위의 실험 결과를 실제 석유화학 플랜트에서 폐기물로 배출되는 폐촉매로부터의 회수공정에 적용하여 본 결과 시약급 시료를 이용하여 제조한 용액에서의 회수거동과 거의 유사한 회수경향을 나타내었으며 99.9% 이상의 높은 순도를 가진 팔라듐을 얻을 수 있었다.

Recently, the demand of palladium (Pd) is increasing sharply causing their excellent chemical or physical property. Field of their application is not only automobile, oil refinery and electronic industrial but also dental materials, glass industry and personal ornaments. In the present study, the electrochemical properties of Pd were investigated by cathodic polarization curves with a variation of rpm and solution temperature using rotating disk electrode. The electrowinning of Pd was investigated using a cyclone. For these, electrowinning experiments were examined with a variation of cell voltage, flow rate at inlet and pH and carried out researches for characteristics of each cases. The diffusion coefficients of Pd calculated from the slope of the plots are 8.96 × 10-6 cm2 s-1 and activation energy of Pd is 12.22 kJ mol-1. From these results, the deposition reaction of Pd is controlled by diffusion of Pd ions to the cathode. Re are proportional to (Sh)0.76. It shows that the flow in cyclone reactor is turbulent flow because the exponent of Sh term is larger than 0.33 which indicates laminar flow. The results of present study shows that electrowinning process using cyclone reactor is a potential process which is more effective and economic for PGMs recovery from dilute solution.

시안을 이용한 PCB 금 박리용액으로부터 사이클론 형태의 전해조를 적용하여 금 회수 연구를 수행하였다. 이때 첨가제로서 전해생성 된 차아염소산나트륨(NaOCl)과 금 도금 첨가제(KG-120)를 사용하였고 이들의 농도와 반응시간에 따른 금의 전해회수 거동을 조사하였다. 전해생성 NaOCl은 침출액 내의 시안과 알칼리 염소화 반응을 촉진함으로써 NaOCl(g)/CN - (g) 비율 1.0 이상에서 약99% 이상 시안을 제거할 수 있었다. 금 전해회수 시 전해생성 NaOCl을 첨가할 경우 NaOCl(g)/CN - (g) 비율이 0.5~2.5일 때 480분내에 금은 98% 회수되었으며 비율이 3.0이상에서는 오히려 금의 회수율이 현저히 감소하는 것을 알 수 있었다. KG-120 용액의 경우, 1.5~4.5%(v/v)까지의 농도범위에서 480분 내에 금이 99% 회수되었으며, 특히 KG-120의 농도가 3.5 및 4.5%(v/v) 일 경우 240 분 내에 금이 96% 이상 회수되어 반응 초기 회수속도가 상대적으로 더 빨랐다. 이로부터 경제성과 효율성을 감안한 최적의 KG120의농도는 3.5%(v/v)로 판단된다.

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.

본 연구는 연료전지 제조공정에서 발생하는 MEA 폐촉매를 대상으로, 무산소 열분해 전처리-염산 침출-사이클론 전해채취-재활용 전극 제조로 이어지는 통합 백금 회수 및 재자원화 공정을 제안하고, 각 단계별 효율 및 소재 특성 변화를 체계적으로 평가하였다. TGA 분석 결과, 500~600°C 부근에서 MEA 내 유기물과 고정탄소가 효과적으로 제거됨을 확인하여 열처리 조건으로 선정하였다. 600°C에서 열처리한 MEA 시료의 백금 침출 실험에서는, 교반속도 250 rpm, 광액농도 5 g/L, H2O2 2 vol%, 염산 6 M, 90°C 등 최적 조건에서 약 71% 이상의 침출 효율(4800 mg/kg)이 나타났다. 고온(1000°C) 열처리 시 백금이 주로 PtO2 형태로 변환되어, 염산 침출에서 ΔG°가 양수(+32 kJ/mol)로 전환됨에 따라 침출 효율이 현저히 저하되는 현상도 관찰되었다. 침출액 내 저농도 백금 회수를 위해 적용한 사이클론 전해채취 공정에서는 유량 10 L/min 조건에서 120분 이내에 98% 이상의 백금 회수 효율을 달성할 수 있었다. 전해로부터 회수된 백금은 XRD 및 SEM 분석을 통해 고순도, 결정성 금속 상태임이 확인되었다. 제조된 Cyclone Pt/C 전극은 상용 Pt/C 전극 대비 10 mA/cm2에서 더 낮은 과전압(30 mV), 더 작은 Tafel slope, 장시간(15시간) 내구성 유지 등 수소 발생 전극 촉매로서 뛰어난 성능과 안정성을 보였다. 이러한결과는 폐 연료전지 MEA로부터 백금을 효율적으로 회수·재활용할 수 있는 실질적 공정 경로를 제시하며, 고부가가치 귀금속 자원순환및 친환경 촉매 제조 분야에 기여할 수 있음을 시사한다.

This study presents an integrated approach for platinum recovery and recycling from spent fuel cell membrane electrode assemblies (MEAs) using oxygen-free pyrolysis, acid leaching, cyclone electrodeposition, and recycled electrode fabrication. Thermogravimetric analysis revealed 500?600°C as the optimal pyrolysis temperature range for effective removal of organics and fixed carbon. MEAs treated at 600°C showed over 71% Pt leaching efficiency (4800 mg/kg) under the following optimal conditions: stirring at 250 rpm, 5 g/L pulp density, 2 vol% H2O2, 6 M HCl, and 90°C. At 1000°C, Pt predominantly formed PtO2, resulting in significantly reduced leaching efficiency owing to a positive Gibbs free energy (ΔG° = +32 kJ/mol) for dissolution in HCl. Cyclone electrowinning enabled rapid and efficient Pt recovery (98% in 120 min at 10 L/min) from dilute leachates. Scanning electron microscopy and X-ray diffraction analyses confirmed that the recovered Pt was highly pure and crystalline. Electrodes fabricated from cyclone-recovered Pt showed superior hydrogen evolution reaction performances compared with that of commercial Pt/C, with a lower overpotential (30 mV at 10 mA/cm2), smaller Tafel slope, and stable operation for 15 h. Overall, this study demonstrates a practical route for the efficient recovery and direct reuse of Pt from waste MEAs, supporting both high-value metal recycling and sustainable electrocatalyst production.

주석도금폐액으로부터 고순도 주석 금속을 회수하는 연구를 실시하였다. 먼저 주석도금폐액을 Iminodiacetic 관능기를 가진 이온교환수지(Lewatit TP 207)를 사용하여 1차적으로 유기물 및 Fe, Zn, Na 등의 불순물을 제거하였고, 2차적으로 Ethylhexyl-phosphate 의 관능기를 가진 이온교환수지(Lewatit VPOC 1026)를 사용하여 잔류하고 있는 불순물들을 모두 제거하여 고순도의 주석용액으로회수하였다. 회수된 주석용액으로부터 고순도 금속주석으로 회수하기 위하여 사이클론식 전해방법을 사용하였으며, 전해채취 결과약 99.98% 순도의 주석을 회수할 수 있었다.

A research for the recovery of the metal with high purity from the waste tin plating solution was carried out. First, tin plating waste solution was tested to remove the organic substances and metallic impurities such as Fe, Zn, Na etc. using ion exchange resin having iminodiacetic functional groups (Lewatit TP 207). Second, the tin solution was purified to obtain the high purity tin solution using ion exchange resin having ethylhexyl-phosphate functional groups (Lewatit VPOC 1026). Finally, 99.98% of the high purity of tin metal can be recovered from the purified solution by cyclone type electrowinning method.

원자력시설 핫셀 (Hot Cell)내에서 핵종실험 시 발생하는 고방사능 분진(Hot Particulate)의 크기는 0.5300 이고 주 핵종은 UO였다. 핫셀 내의 고방사능 분진을 제거하기 위해 사이클론과 Bag/HEPA필터로 구성된 장치를 고안하였고, 이 장치의 사이클론에 의해 고방사능 분진을 최대로 포집할 수 있는 실험조건을 제시했다. 모의입자의 크기가 클수록 입자의 포집효율은 높았다. 모의 입자의 크기가 5 이상일 때, 입자의 포집효율은 보다 높았다. 모의 입자의 크기가 1.0 보다 작을 때, 포집효율은 보다 작았다. 모의 입자의 유입속도가 12 m/sec보다 클 때, 포집효율은 보다 높았다. 그러나 유입속도가 17 m/sec 보다 클 때 포집효율의 증가율은 크지 않았다. 모의입자의 포집효율은 Vortex Finder의 길이가 7.2 cm이하일 때, 길이의 증가와 함께 높아졌지만 7.2 cm 이상일 때는 낮아지기 시작했다. 그러므로 Vortex Finder의 길이가 7.2 cm 일 때, 최대포집효율을 나타냈다. 사이클론 밑에 보조콘 부착 시 모든 속도 범위에서 약 평균 정도 포집효율이 증가하므로 보조콘 부착효과가 크지 않았다.

The size and main ingredient of hot particulate generated during the nuclide experiment in hot cells of nuclear facilities were 0.5300 m and UO. A cyclone filter equipment which consists of a cyclone and Bag/HEPA filter was devised to remove hot particulate generated during the nuclide experiment in hot cells of nuclear facilities. The experimental conditions to maximize the collection efficiency of hot particulate were suggested through experiments done with the cyclone filter equipment. With the large size of simulated particulate, the collection efficiency of the particulate was high. When the size of simulated particulate was more than 5 m, the collection efficiency of the particulate was more than and when the size of simulated particulate was less than 1.0 urn, the collection efficiency decreased by less than . If the inflow velocity of simulated particulate was increased, the collection efficiency of the particulate was also increased. When the inflow velocity of simulated particulate was more than 12m/sec, the collection efficiency was higher than , but after 17 m/sec inflow velocity, no change observed. The collection efficiency of the simulated particulate can be enhanced with the length of vortex finder inside the chamber. With the length of vortex finder, 7.2cm, the observed collection efficiency of the particulate was the maximum. Moreover, when the sub-cone was attached under the cyclone, the collection efficiency of cyclone increased . It was found that effect by attachment of sub-cone was not serious.