http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
In-situ molybdenum nano-attached particle synthesis from spent Mo scrap.
Han, Chulwoong,Kim, Byungmoon,Choi, Hanshin American Scientific Publishers 2014 Journal of nanoscience and nanotechnology Vol.14 No.10
<P>Radio frequency thermal plasma is a versatile process for engineering powder preparation owing to its high energy density and reactivity. Molybdenum powders were prepared from molybdenum sheet scrap by RF thermal plasma in association with powder comminution process. Molybdenum scrap which was used in high temperature environment was friable enough to be broken into micropowders by hammer milling. Spherical molybdenum micro-powder was obtained from the hammer milled powders were treated via thermal plasma. On the other hand, vaporization and condensation pathway for nanoparticle synthesis is largely dependent on both thermo-physical properties and thermal plasma properties. In this regard, molybdenum trioxide was chosen for the feedstock of nanoparticle synthesis. Additional reactivity of argon-hydrogen thermal plasma, oxide feedstock was fully reduced to bcc molybdenum. Considering different reaction pathway of each feedstock, molybdenum nanoparticle attached molybdenum spherical micro-powder could be effectively synthesized by feeding a blended feedstock of molybdenum micro-powder and molybdenum trioxide micro-powder into argon-hydrogen thermal plasma.</P>
Recovery Of Valuable Metals In Tin-Based Anodic Slimes By Carbothermic Reaction
Han, Chulwoong,Kim, Young-Min,Son, Seong Ho,Choi, Hanshin,Kim, Tae Bum,Kim, Yong Hwan PAS 2015 ARCHIVES OF METALLURGY Vol.60 No.2
<B>Abstract</B><P>This study investigated the recovery of anodic slimes by carbothermic reaction in the temperature range of 973~1,273K and amount of carbon as a function of time. Tin anodic slime samples were collected from the bottom of the electrolytic cells during the electro-refining of tin. The anodic slimes are consisted of high concentrated tin, silver, copper and lead oxides. The kinetics of reduction were determined by means of the weight-loss measurement technique. In order to understand in detail of carbothermic reaction, thermodynamic calculation was carried out and compared with experiments. From thermodynamic calculation and experiment, it was confirmed that Sn-based anodic slime could be reduced by controlling temperature and amount of carbon. However, any tendency between the reduction temperature and carbon content for the reduction reaction was not observed.</P>
Nano-Attached Tungsten Particle Synthesis and Sintering Behaviors
Chulwoong Han,Hanshin Choi,Byoungmoon Kim 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5
The reduction of sintering temperatures in industrial processes is advantageous for both energy efficiency and material properties in powder metallurgy. Based on the well-known size effects of nano-particles on sintering processes, nano-particles were intentionally used as a homogeneous sintering activator for micro-particles in this study. Two kinds of tungsten bimodal feedstocks which consisted of nano-particles and microparticles were prepared and sintered by spark plasma sintering processed. Even at the low sintering temperature of 1,250 °C and the short sintering time of 300 sec, relatively high densities could be achieved. Depending on the content of the nano-particles in the charged feedstock, the sintered body exhibited different morphological features. Density, field emission scanning electron microscopy, transmission electron microscope was used for analysis.
PCB 제조 공정 중 발생한 슬러지 내 유가금속 회수를 위한 건식야금 공정에 관한 연구
한철웅,손성호,이만승,김용환,Han, Chulwoong,Son, Seong Ho,Lee, Man-Seung,Kim, Yong Hwan 한국자원리싸이클링학회 2019 資源 리싸이클링 Vol.28 No.6
본 연구에서는 인쇄회로기판(PCB) 제조 공정 중 발생한 슬러지 내 구리를 회수하기 위한 건식야금 공정 변수에 대해 조사하였다. 에칭 및 도금 공정에서 발생한 슬러지는 전처리 공정을 통해 수분과 유기물을 제거하였다. 열역학 상평형 계산을 통해 평형상과 슬래그 시스템을 선정하였으며, 유가금속 회수율에 미치는 건식야금 공정 변수에 대하여 조사하였다. This study investigated the effect of process variables for smelting of recovery of valuable metal in the sludge generated from PCB. The moisture and organics in the sludge was removed by preteatment process. The phase equilibria and slag system was selected by thermodynamic phase calculation program and the process variable of pyro-metallurgical process such as reductant. Smelting temperature and holding time for a recovery of valuable metal was studied.
인쇄회로기판 제조공정 중 발생한 슬러지 내 건식환원 처리를 통한 구리 회수를 위한 슬러지 분석 및 열역학적 계산
한철웅,김영민,김용환,손성호,이만승,이기웅,Han, Chulwoong,Kim, Young-Min,Kim, Yong Hwan,Son, Seong Ho,Lee, Man Seung,Lee, Ki Woong 한국자원리싸이클링학회 2017 資源 리싸이클링 Vol.26 No.5
본 연구에서는 PCB 도금 및 에칭 공정 중 발생한 슬러지의 분석을 통해 건식환원처리가 가능한 슬래그 시스템을 선정하고자 하였으며 이를 바탕으로 슬러지 내에 존재하는 유가금속의 회수 가능성에 대하여 실험적 및 열역학적 검토를 하였다. 슬러지는 $100{\sim}500^{\circ}C$의 온도구간에서 건조한 후 슬러지의 형상과 화학성분 및 상을 분석하였다. 슬러지의 건식환원처리 가능성은 FactSage를 이용한 열역학적 계산을 통해 조사하였다. In this study, we tried to select a slag system capable of pyro-metallurgical process through analysis of sludge generated from PCB plating and etching process solution. Based on this, the possibility of extracting valuable metals in the sludge was studied by experimental and thermodynamic approaches. The sludge was dried at $100{\sim}500^{\circ}C$ and the morphology, chemical composition and phase of the sludge were analyzed. The possibility of pyro-metallurgical process of sludge was investigated through thermodynamic approach using FactSage software.
알루미늄 캔 스크랩의 용탕처리 시 알루미늄 합금 회수에 미치는 플럭스의 영향
한철웅,안병두,김대근,이만승,김용환,Han, Chulwoong,Ahn, Byung-Doo,Kim, Dae-Guen,Lee, Man Seung,Kim, Yong Hwan 한국자원리싸이클링학회 2020 資源 리싸이클링 Vol.29 No.1
This study investigates the effect of flux type and mixing ratio on efficiency in aluminum can scrap recycling using induction furnace. The removal of surface coating layer of aluminum can scrap was possible through heat treatment at about 500 ℃ for about 30 min. The temperature for the melting process was set to be slightly above the melting temperature of the aluminium can scrap. The molten metal treatment was performed with different types of flux and mixing ratio. As a result, The optimum efficiency of Al recovery ratio was revealed when the process was performed with at least 3 wt.% of the flux (Salt and MgCl<sub>2</sub> mixture of ratio 70:30) at 750 ℃. The mechanical property of the recovered Al alloy showed that the tensile strength is about 249 MPa and elongation is about 14 %. This result was found to be similar to the mechanical property of the virgin Al 5083 alloy.
Double Step Sintering Behavior Of 316L Nanoparticle Dispersed Micro-Sphere Powder
Jeon, Byoungjun,Sohn, Seong Ho,Lee, Wonsik,Han, Chulwoong,Kim, Young Do,Choi, Hanshin Walter de Gruyter GmbH 2015 Archives of metallurgy and materials Vol.60 No.2
<B>Abstract</B><P>316L stainless steel is a well-established engineering material and lots of components are fabricated by either ingot metallurgy or powder metallurgy. From the viewpoints of material properties and process versatility, powder metallurgy has been widely applied in industries. Generally, stainless steel powders are prepared by atomization processes and powder characteristics, compaction ability, and sinterability are quite different according to the powder preparation process. In the present study, a nanoparticle dispersed micro-sphere powder is synthesized by pulse wire explosion of 316L stainless steel wire in order to facilitate compaction ability and sintering ability. Nanoparticles which are deposited on the surface of micro-powder are advantageous for a rigid die compaction while spherical micro-powder is not to be compacted. Additionally, double step sintering behavior is observed for the powder in the dilatometry of cylindrical compact body. Earlier shrinkage peak comes from the sintering of nanoparticle and later one results from the micro-powder sintering. Microstructure as well as phase composition of the sintered body is investigated.</P>
파쇄 기구에 따른 알루미늄 캔 재자원화 공정 중 발생한 블랙 드로스 내 알루미늄 회수에 관한 연구
한철웅,손성호,안병두,김대근,이만승,김용환,Han, Chulwoong,Son, Seong Ho,Ahn, Byung-Doo,Kim, Dae-Guen,Lee, Man Seung,Kim, Yong Hwan 한국자원리싸이클링학회 2017 資源 리싸이클링 Vol.26 No.4
본 연구는 UBC 재활용 용해공정 중 발생한 블랙 드로스 내 금속 알루미늄을 회수하기 위해 압축 및 충격 파쇄 공정에 따른 알루미늄 회수율에 대하여 조사하였다. 초기 알루미늄 블랙 드로스는 대부분 구형의 형상으로 약 10~40 mm 크기였다. 또한 블랙 드로스의 주요 구성 성분은 할라이트(NaCl), 실바이트(KCl), 스피넬($MgAl_2O_4$) 및 알루미나($Al_2O_3$)로 나타났다. 알루미늄 금속의 회수율 시험은 서로 다른 파쇄 기구를 갖는 죠 크러셔와 햄머밀 공정으로 진행하였다. 파쇄 기구에 따른 알루미늄 금속 회수 실험결과, 죠 크러셔 공정은 금속과 비금속 혼합물을 분리할 수 있었으나 햄머밀 공정은 금속과 비금속의 분리가 어려운 것으로 관찰되었으며 알루미늄 블랙드로스 내 금속 알루미늄을 회수하기 위한 파쇄 공정은 죠 크러셔 공정이 더 효과적인 것으로 보여진다. This study investigated the recovery of metallic aluminium in the black dross generated from used beverage can recycling process with crushing mechanism such as compression and impact. The as-received Al black dross had a spherical shape, and its size was about 10~40 mm. Also, The X-ray diffraction pattern showed that the main contents of black dross are composed of halite (NaCl), sylvite (KCl), spinel ($MgAl_2O_4$) and corundum ($Al_2O_3$). A metallic aluminium recovery test was performed using jaw crusher and hammer mill having different crushing mechanism. It was analysed that Jaw crushing process can separate into metallic aluminium and non metallic constituents. However, hammer milling process shows significant difference on the separation results. It was found that jaw crushing process was effective for recovery of metallic aluminium in the black dross than that of hammer milling process.
Oxide Formation In Metal Injection Molding Of 316L Stainless Steel
Jang, Jin Man,Lee, Wonsik,Ko, Se-Hyun,Han, Chulwoong,Choi, Hanshin PAS 2015 ARCHIVES OF METALLURGY Vol.60 No.2
<B>Abstract</B><P>The effects of sintering condition and powder size on the microstructure of MIMed parts were investigated using water-atomized 316L stainless steel powder. The 316L stainless steel feedstock was injected into micro mold with micro features of various shapes and dimensions. The green parts were debound and pre-sintered at 800°C in hydrogen atmosphere and then sintered at 1300°C and 1350°C in argon atmosphere of 5torr and 760torr, respectively. The oxide particles were formed and distributed homogeneously inside the sample except for the outermost region regardless of sintering condition and powder size. The width of layer without oxide particles are increased with decrease of sintering atmosphere pressure and powder size. The fine oxides act as the obstacle on grain growth and the high sintering temperature causes severe grain growth in micro features due to larger amount of heat gain than that in macro ones.</P>