• Resources Recycling
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• v.33 no.2
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• pp.24-36
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• 2024

The lithium-ion battery recycling process has been classified into direct recycling, hydrometallurgical process, and pyrometallurgical process. The commercial process based on the hydrometallurgical process produces black mass through pretreatment processes consisting of dismantling, crushing and grinding, heat treatment, and beneficiation, and then each metal is recovered by hydrometallurgical processes. Since all lithium-ion battery recycling processes under development conducts hydrometallurgical processes such as leaching, after the pretreatment process, to produce precursor raw materials, this article suggests a classification method according to the pretreatment method of the recycling process. The processes contain sulfation roasting, carbothermic reduction roasting, and alloy manufacturing, and the economic feasibility of the lithium-ion battery recycling process can be enhanced using unused by-products in the pretreatment process.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.2
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• pp.173-179
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• 1999

The effect of the surface activation treatment on the crystallization of the amorphous silicon film was investigated. The amorphous silicon film was deposited on the silica substrate with LPCVD technique. Wet blasting with silica slurry or exposure with Nd:YAG laser beam was applied on the amorphous silicon film before annealing for the crystallization. For the analysis of the crystallinity, XRD, Raman, and SEM were employed. In this investigation, the prior surface activation treatment like silica wet blasting or Nd:YAG laser beam exposure before annealing for the crystallization were found to be effective in the enhancement of the crystallization. It is believed that these treatment lower the activation energy required for the crystallization of the amorphous silicon film.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.353.1-353.1
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• 2016

다공성 물질은 동공의 크기에 따라 미세동공(Micropore), 메조동공(Mesopore), 거대동공(Macropore)으로 나누어 분류한다. 다공성 재료의 장점은 높은 비표면적으로써, 촉매, 센서, 연료전지 전극, 에너지 저장장치 등으로의 이용 가능성을 보여주는 연구가 활발히 보고되고 있다. 종래의 연구는 두 가지 이상의 원소로 구성된 박막을 제작한 후 전기화학적 분해법, 선택적 용해법 등 습식공정을 통해 다공성 구조체를 제작하였다. 하지만 본 연구에서는 Au, Ag 타겟과 $CH_4$ gas를 이용해 ICP-assisted reactive magnetron sputtering 장비를 활용하여 450 nm 두께의 Au-C, Ag-C 박막을 제작하였다. 이후 연속적으로 RF 250 W를 ICP antenna 에 인가하여 $O_2$ plasma dealloying 공정을 통해 탄소(Carbon) 만을 선택적으로 제거함으로써, 건식 공정만으로 Si wafer ($10{\times}10mm^2$) 기판 위에 250 ~ 300 nm 두께의 다공성 Au, Ag 박막을 제작하였다. SEM (Scanning Electron Microscopy)를 활용하여 표면, 단면 형상을 관찰해 다공성 구조를 확인하였으며, AES (Auger Electron Spectroscopy)를 통해 plasma dealloying 전 후 박막의 조성변화를 관찰하였다. 따라서 plasma dealloying 공정으로 제작된 다공성 Au, Ag 박막은 기존의 습식 공정 대비 청결하고 신속한 공정이 가능하며 높은 재현성을 통해 위의 적용분야에 보다 쉽게 사용될 수 있을 것으로 기대된다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.2
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• pp.166-170
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• 2000

Amorphous calcium carbonate was prepared by wet chemical method and performed the control of their shape using crystalline calcium carbonate that prepared from oyster shell by the $CO_2$ gas blowing method. As a result, amorphous calcium carbonate was obtained by the dissolution process of crystalline calcium carbonate in the dil-HC1 solution, mixing of sodium carbonate solution, precipitation and filtering with high speed. And using the amorphous calcium carbonate of mud type, crystalline calcium carbonates with cubic, needle, spindle, spherical and plate shape were obtained in the temperature rang of 2~$85^{\circ}C$ and reaction time range of 5~60 minute.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.4
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• pp.640-647
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• 1996

It has been found that an white precipitates at the inside surface is a common characteristics of soda-lime-silica glasses which have not undergone special surface treatments during hot weather season. In this study, the white deposits were examed using by solution method, surface analysis etc., and the dependence of weathering on the atmospheric condition was also investigated. As a results, the white precipitates on the glass surface was discorved as carbonates like $Na_2CO_3{\cdot}H_2O,CaCO_3$. Coming to atmosphere-dependence, it was shown that the glass made and stored at sea shore province had 3 times much severe weathering than that at land province.

• Resources Recycling
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• v.8 no.5
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• pp.28-33
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• 1999

Trus paper presenls a hydrometallurgical process Tor recovcnng ~uckcals mckcl sulfate fiom the spent nickel-cadrnlum bauery in whch c:,dmi~lm war re~novcdb y vapowing m e h d in vacuum. F ~ s ts,e lcct~vcc rushing and classification mell~odw ere performed to separate iron physically and the nickel-rich sample (over 80% nickel) was obtained. Ths sarnple was dissolved in sulf~ uiuica cid to obtain a luckcl sulfatc soluho~d~o se to its seluradon painl. TIE Cree acid in the unpurificd nickcl solut~onw as neutl-dized and iron war ve~novedk om the solulmn Thc mckel sulhte solution was c~yst~llizeadt around 45'C to obtain ruckel sulfate henahyril-ate.

• Resources Recycling
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• v.28 no.1
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• pp.15-22
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• 2019

There are three hydrometallurgical methods by which pure alumina can be prepared, such as hydrolysis of aluminum alkoxides, thermal decomposition of ammonium alum and thermal cracking of ammonium aluminum carbonate (AACH). The effect of solution pH and temperature and the nature of the impurities on the phase transition and the purity of the alumina thus produced was investigated. Hydrolysis of aluminum alkoxides and thermal decomposition of ammonium alum produce ${\alpha}$ and ${\gamma}$ alumina, while only ${\alpha}$ alumina can be produced by thermal cracking of AACH.

• Journal of ILASS-Korea
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• v.24 no.1
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• pp.8-14
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• 2019

The purpose of this study is to develop a packing-free wet scrubber to prolong the maintenance interval compared with the conventional packed bed wet scrubbers with which frequent operation stops are unavoidable to clean the packing materials. The main- and interaction-effects were quantitatively analyzed by regression analysis for the measured ammonia scrubbing data from the experiments prepared by experimental design. The scrubbing efficiency of the newly developed wet scrubber was found to be over 95% under the condition of flue gas flow rate of 90CMM and liquid-to-gas ratio $2l/m^3$ for all considered trials of experimental design. The interaction effect between the inlet duct spray and the filter was found to be important, which controls the droplet growth due to the droplet collisions between the duct- and scrubbing tower-spray. The presented methodology to analyze the impacts of operational and design factors on the scrubber efficiency showed potential for applications to optimize the future flue gas abatement process in semiconductor plants.

• Resources Recycling
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• v.26 no.3
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• pp.79-91
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• 2017

The core of Hydrogen Fuel Cell Vehicles (FCV) is polymer solid fuel cell (PEFC), and the core material that generates electrochemical electricity in the cell is platinum catalyst. Platinum is localized in South Africa and Russia, and the world production of Pt is about 178 tons per year, which is expensive and recycled. At present, the amount of Pt used in PEFC is $0.2{\sim}0.1mg/cm^2$. In order to reduce the price of the battery and increase the FCV supply, the target is to reduce the amount of Pt used to $0.05{\sim}0.03mg/cm^2$. $Pt-Pd/Al_2O_3$, Pt/C, Pt/GCB, Pt/Au/C, PtCo/C, PtPd/C, etc. by using polyol method using nano Pt, improved Cu-UPD/Pt substitution method and nano-capsule method, Have been researched and developed, and there have been reported techniques for improving the activity of Pt catalysts and stabilizing them. This paper investigates the production technology of nano-Pt and nano-Pt catalysts, recycling of spent Pt catalysts and application trends of Pt catalysts.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.158.2-158.2
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• 2010

본 논문은 정부의 연구 지원에 의해 폐유를 유화 방법으로 재활용한 유화정제연료유의 저장안정성 측정방법을 마련하고자 실시하였다. 국내외 유화정제연료유 저장안정성 시험방법이 마련되지 않아 ASTM D 3707, 지식경제부 '석유대체연료의 성능평가기준과 품질시험방법 등에 관한 고시' 별표4 유화연료유 저장안정성 평가방법(습식법) 등 유화연료유의 저장안정성 시험방법을 근간으로 하여 $40^{\circ}C$에서 30일 동안 저장용기에 저장하면서 매 10일 마다 상 하층 수분함량을 측정하는 방법을 제시하였고, 이에 대한 전반적인 연구 내용을 언급하였다.