• 자원리싸이클링
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• 제28권3호
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• pp.21-25
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• 2019

The utilization of incineration ash from municipal waste must be promoted to solve the social problem on the shortage of final disposal site. In this research, metals should be recovered to avoid the damage of the crushing machine during the utilization of incineration ash in cement industry. In fact, incineration bottom ash from municipal waste contains iron in 3-5%. Nonferrous metal and stainless steel in 1% is also included. The research and development on the physical recovery process was performed not only to remove the metals but also to recover high grade products. Metals were separated from incineration ash in Maruya Co. Ltd.. In fact, iron scrap recovered by magnetic separation can be selled. After that, mixed metal was separated from incineration ash using screen. In this research, mixed metal tried to divided copper, aluminum, brass and stainless steel using drum type magnetic separation, eddy current separation and high magnetic separation. As a result, recovered iron had an 80% for the grade. Aluminum was recovered by eddy current separation without copper and brass.

• 한국산업융합학회 논문집
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• 제4권1호
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• pp.61-69
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• 2001

Polycarbonate(PC) membranes for oxygen enrichment from air were prepared by the wet phase inversion method. In order to improve oxygen separation performances of the PC membrane, the effect of the added ethanol(nonsolvent) and $CuCl_2$(metal salt) concentration in the casting solution on morphology, oxygen permeability ami $O_2/N_2$ separation factor of the membrane was studied. In addition, tensile strength and elongation at break of the membrane were investigated. An asymmetric membrane with a dense top layer and a porous sublayer was obtained. The thickness of the dense top layer decreased with increasing amount of nonsolvent additive. Compared with pure PC membrane without additive(metal salt), the oxygen permeability and $O_2/N_2$ separation factor of the $PC/CuCl_2$ membrane are significantly improved. The oxygen permeability and $O_2/N_2$ separation factor is $5.25{\times}10^{-9}cm^3(STP){\cdot}cm/cm^2{\cdot}sec{\cdot}cmHg$ and 4.5, respectively. This improvement might be due to good interaction between metal salt and oxygen.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권5호
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• pp.56-64
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• 2013

After the law has been enacted for the prevention and recovery of mining damage in 2005, efforts of remediation have been started to recover heavy metal contaminated soils in agricultural land near mining sites. As part of an effort, the upper part of cultivation layer has been treated through covering up with clean soil, but the heavy metal contamination could be still spreaded to the surrounding areas because heavy metals may be remained in the lower part of cultivation layers. In this study, the most frequently occurring arsenic (As) contamination was selected to study in agricultural land nearby an abandoned metal mining site. We applied separation technologies considering the differences in the physical characteristics of soil particles (particle size, density, magnetic properties, hydrophobicity, etc.). Based on physical and chemical properties of arsenic (As) containing particles in agricultural lands nearby mining sites, we applied sieve separation, specific gravity separation, magnetic separation, and flotation separation to remove arsenic (As)-containing particles in the contaminated soil. Results of this study show that the removal efficiency of arsenic (As) were higher in the order of the magnetic separation, flotation separation, specific gravity separation and sieve separation.

• Elastomers and Composites
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• 제30권3호
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• pp.229-234
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• 1995

Membrane process has been applied widely to petroleum chemistry, fine chemistry, polymer, electronics, food, bioprocessing, and wastewater treatment process. Membrane process has advantage that there's no phase change through separation, energy consumption is smaller than other separation processes. And equipment investment and operation cost are inxpensive too. We prepared the silicone rubber membrane and then separated the heavy metal ion from wastewater. Silicone rubber membrane was prepared using a superitical fluid process and heavy metal ions were separated from the chromium nitrate, ferric sulfate, cupric sulfate, nickel sulfate aqueous solution. The pressure difference between top and bottom of separation apparatus was preserved by vacuum pump, and the removal amount of heavy metal at each separation step were analyzed by instrumental analysis, AAS. The surface and pore of silicone rubber membrane was investigated using SEM, and the capability of wastewater treatment using a silicone rubber membrane was proposed as calculated removal rate of heavy metal after comparing removal amount of heavy metal to amount of heavy metal in mother solution by AAS analysis.

• Korean Chemical Engineering Research
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• 제57권4호
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• pp.484-491
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• 2019

산업적으로 중요한 가치를 지니는 폴리프로필렌 합성의 원료인 프로필렌을 고순도로 얻기 위해서는 효율적인 프로필렌/프로판 분리 기술이 필요하다. 기존 증류 공정은 프로필렌과 프로판의 유사한 물리화학적 성질로 인해 매우 높은 에너지가 소모되기때문에, 흡착분리 기술이큰관심을받고있다. 본연구에서는 Grand Canonical Monte Carlo (GCMC) 분자 모사를 활용하여 기공의 형태가 다른 두 종류의 유무기복합다공체(Metal-Organic Frameworks)의 빈금속배위자리(open metal sites) 흡착 강도를 임의로 조절하며 프로필렌/프로판 흡착 분리 성능의 변화를 조사하였다. 흡착 분리 성능은 작업 용량, 선택도, Adsorption Figure of Merit (AFM) 등으로 평가하였고, 이를 통해 흡착제가 최적의 프로필렌/프로판 분리 성능을 가지기 위해 필요한 흡착 사이트의 밀도 및 강도 그리고 온도 조건 등을 제시하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권5호
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• pp.46-55
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• 2013

The main objective was to evaluate the efficiencies of different separation techniques, such as gravity separation, magnetic separation, and aerial separation. Zinc and cadmium removal efficiencies by gravity separation and magnetic separation were 28.3~29.3% and 19.1%, respectively, and were higher than the efficiency obtained by aerial separation. Results showed that the combination of gravity separation and magnetic separation in series which was to maximize the removal efficiencies gave removal efficiency of 21.5~38.7% for zinc and 22.1~23.4% for cadmium. The mass of soil meeting the regulation standards for zinc and cadmium after retrieval from the combined separation process accounted for approximately 80% of the treated soil that would be reusable without the pre-treatment procedure as the neutralization process using in the soil washing method. Physical separation techniques utilizing heavy metal properties are the alternative method to remediate heavy-metal contaminated soils in environmental and economic aspects.

• 한국컴퓨터정보학회논문지
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• 제22권10호
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• pp.1-7
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• 2017

In this paper, the separation force measuring system is developed. The separation force aries due to adhesive strength between semiconductor epoxy molding compound(EMC) and the metal plate in semiconductor formed plate. In general, when removing the metal plate in semiconductor formed plate from semiconductor epoxy molding compound, excessive strength can result in a increase in semiconductor defect rates, or conversely, if too little force is exerted on the metal plate in semiconductor formed plate, the semiconductor production rates can decrease. In this study, the design criteria for the selection of the AC servo motor, the role of the ball screw, the relationship between the load cell and the ball screw, and the rate of deceleration are given. In addition, minimizing the reject rate of semiconductors and maximizing the semiconductor production rate are achieved through the standardization of the collected separation force data measured by the proposed system.

• 분석과학
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• 제8권3호
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• pp.259-264
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• 1995

수용액서 poly-NTOE(1, 12-diaza-3, 4:9, 10-dibenzo-5, 8-dioxacyclopentadeca-1, 12-ylene-2, 7-dihydroxyoctamethylene)를 흡착시킨 실리카겔을 고정상으로 하는 액체 크로마토그래피를 이용하여 혼합 금속이온용액으로부터 전이금속 및 후전이금속이온들의 분리효율을 결정하였다. pcly-NTOE와 금속이온들간의 결합상수 및 분리인자들의 순위는 전이금속이온의 경우 Co(II)Zn(II)였으며, 후전이금속이온들의 경우 Cd(II)

• Journal of Electrochemical Science and Technology
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• 제10권1호
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• pp.14-21
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• 2019

Supported liquid membrane process usually is used for recovering or enrichment of valuable metals in the industrial wastewater. But, even if the metals in the wastewater was separated with high chemical selectivity, it cannot be enough concentrated since separation performance of supported liquid membrane (SLM) process is limited by concentration gradient between feed solution and stripping solution. If metal concentration in the stripping solution to be enough low, transport of metal through membrane can be accomplishment constantly. Therefore, Electrodialysis (ED) has been placed after SLM process and the stripping solution of SLM was used as the feed solution for the ED process. Transport of ions in the solutions is successfully performed by ED process. Thus, the metal concentration in the stripping solution does not rise as to stop ion transport. Besides, valuable metals easily are concentrated by ED process for re-use. In this study, effects of operation parameters like initial Cd(II) concentration, HCl concentration in the feed solution of SLM and applied voltage are investigated on separation efficiency, flux and permeability of the both processes. As the feed solution concentration increased, all performance values has increased. When initial concentration of 100 mg/L is used, separation performances (SP) are 55% and 70%, for SLM and consecutive process, respectively. The best HCl concentration in the feed solution of SLM has determined as 2 M, in this conditions SP are 64% and 72%, for SLM and consecutive process, respectively. With increased of applied voltage on ED process, SP of the consecutive process has been raised from 72% to 83%. According to the obtained experimental data, consecutive process has better separation performance than SLM. When the separation performances of both processes were compared for the same operating conditions, it was determined higher the separation efficiency, permeability and flux values of the consecutive process, 8%, 9% and %10.6, respectively. Consequently, the use of the consecutive process increases the performance efficiency of both processes. The consecutive process studied has quite a good chemical separation efficiency, and enrichment capability. Moreover, this process requires few water and energy.

• 대한화학회지
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• 제39권7호
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• pp.524-529
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• 1995

pH 1에서 15-crown-5(SGBM)을 결합시킨 silica gel를 고정상으로 하는 액체 크로마토그래피을 이용하여 혼합 금속이온 용액으로부터 금속이온들의 분리효율을 결정하였다. 여러가지 SGBM-금속이온들간의 결합상수 및 분리인자들을 측정한 결과 그 순위는 Li(Ⅰ) < Sr(Ⅱ) < Na(Ⅰ) < Cu(Ⅱ) < Mg(Ⅱ) < K(Ⅰ) < Ca(Ⅱ) < Bi(Ⅲ) < Sb(Ⅲ)로 나타났다. 이러한 사실은 금속이온의 크기 효과 및 전자 밀도 효과에 의해서 결정됨을 알 수 있었으며, 또한 알칼리, 알칼리 토금속이온 및 $Cu^{2+}$이 혼합된 용액에서 $Sb^{3+}$의 분리효율이 다른 이온들에 비해서 훨씬 좋게 나타남을 알았다.