• 자원리싸이클링
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• 제25권4호
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• pp.49-53
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• 2016

주석 폐자원으로부터 회수된 주석 조금속을 메탄술폰산 전해액에서 전해정련을 수행하여 고순도 주석을 회수하고자 하였다. 전해정련층 표면형상을 관찰한 결과 주석 전해정련 시 glycol계 유기첨가제를 통해 균일하게 주석이 전착되었고, 수지상 형상 및 박리현상은 발생하지 않았다. 주석 조금속 및 전해정련층의 순도를 ICP-OES로 분석한 결과 주석 조금속은 은, 구리, 납, 니켈 등의 불순물이 함유되어 97.280 wt.%의 주석순도를 나타내었고, 전해정련을 수행 후 순도 분석결과 주석의 순도는 99.956 wt.%으로 증가하였다. 순환 전압전류 시험결과 유기첨가제는 주석 전해정련 시 불순물의 환원반응을 억제 또는 가속시키는 역할을 하는 것으로 판단된다.

• 한국식품과학회지
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• 제29권1호
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• pp.15-20
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• 1997

탈검, 탈산, 탈색과 탈취 등의 정제 과정이 참기름에 존재하는 항산화 물질과 금속의 함량에 미치는 영향과 $70^{\circ}C$에서 저장 중 참기름의 산화 안정성과 항산화물질의 변화에 관하여 시험하였다. 철, 구리, 마그네슘 및 아연의 금속은 탈검 과정에서 거의 대부분이 제거되었다. 조참기름과 탈검유는 저장 동안에 총 휘발성 화합물의 양에 거의 변화가 없었으며, 탈산유와 탈취유는 저장 초기에서부터 총 휘발성 화합물의 양이 현저하게 증가하였다. 동정된 휘발성 산화 생성물 중 hexanal과 pentanal의 변화가 가장 뚜렷하였으며, 탈산, 탈색과 탈취 등의 정제 과정을 거친 시료들은 저장 초기에 이러한 산화 생성물의 증가가 현저하였다. Sesamin은 정제와 저장동안에 비교적 안정하였고, sesamolin은 정제 과정과 저장 중에 뚜렷하게 감소하였다. Sesamol은 탈산 과정까지는 감소하다가 탈색 과정을 거치면서 급격히 증가하였고, 탈취 과정에서 거의 제거되었다. 저장 중 sesamolin이 계속 감소되면서 sesamol의 증가가 수반되었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.229-241
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• 2008

In order to investigate stabilization effect on As-contaminated soils treated by zero-valent iron(ZVI) and industrial by-products, batch tests and column tests were carried out with As-contaminated soils collected from farmland around the abandoned mine site. In batch tests, ZVI and industrial by-products(blast furnace slag, steel refining slag and oyster shell powder) were used as treatment materials to reduce As. Industrial by-products were mixed with As-contaminated soils, in the ratio of 1%, 3%, 5% and 7% on the weight base of dried soil. After incubation, all samples showed the reduction of As concentration and it was expected that ZVI and steel refining slag were effective treatment materials to remove As among treatment materials used in batch test. In column tests, columns were made by acrylic with the dimension of diameter=10cm, height=100cm, thickness=1cm and these columns were filled with untreated soils and treated soils mixed with ZVI and steel refining slag(mixing ratio=3%). Distilled water was discharged into the columns with the velocity of 1 pore-volume/day. During test, pH, EC, Eh and As concentration were measured in the regular term(1 pore-volume). As a result, ZVI and steel refining slag were shown 93%, 62% reduction of As concentration respectively by comparison with untreated soils. Therefore, if ZVI and steel refining slag are used as treatment materials in As-contaminated soils, it is expected that the As concentration in soils is reduced effectively.

• 아시안잔디학회지
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• 제18권1호
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• pp.29-36
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• 2004

The efficient refinement of seed is required to reduce the cost and labor input in artificial propagation of wild plant. This study was carried out to develop methods for collecting and refining tiny seeds from wild plants. For obtaining Phragmites communis seeds, the inflorescence was cut into small fragments using a Straw Cutter and subsequently detached pappus hairs from seed coat by Hammer Mill. The primary refined seeds were passed 1.0 mm sieve. The screened seeds were subjected to Seed Blower with wind speed of 0.25 mㆍsec-1 to collected intact and well-ripen seeds. The seeds of Imperata cylindrica were refined as follows. Inflorescences were cut using a Straw Cutter first. The pappus was removed from cut fragments using a Hammer Mill and subsequently subjected to Seed Scarifier at 500rpm for 60 sec. for further separation. The separated seeds were passed 1.0 mm screen and collected after blowing with Seed Blower of wind speed of 0.15 mㆍsec-1. When the amount of seed was too little to refine with Seed Scarifier and Blower, the procedure was slightly modified from the procedure described above. The crude seed mixture obtained from Hammer Mill step was hand-refined roughly and then immersed into cone. (95%) sulfuric acid for 2 min. and collected floating portion after dilution of sulfuric acid solution 100 times with tap water. The collected seeds were dried and passed 0.149 mm sieve. During seed refining process using mechanical or sulfuric acid treatments, a small portion of damaged seed were evolved, however, the amount was not noticeable as compared to the total amount of collected seeds. Because the germination percentages between hand-refined seeds and seeds refined by above methods were not statistically different, the developed procedures for refining tiny seed of wild plants are helpful to reduce the cost and labor input in artificial propagation of two species.

• 자원리싸이클링
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• 제27권6호
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• pp.38-43
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• 2018

유리생산공정에서 발생하는 요업로 전극봉인 폐주석 산화물로부터 가스환원공정과 전해정련을 통하여 고순도 주석을 회수하기 위한 연구를 수행하였다. 메탄가스 환원공정을 통해 99% 순도의 조주석을 회수하고, 불순물을 미량 제어하였다. 주석의 전해정련시 전류밀도가 $60A/dm^2$이고 전해액의 황산농도가 0.75 mol일 때 99.979%의 고순도 주석이 96.8% 회수되었다. 그리고 전극봉에 포함된 Pb, Sb 등의 독성 불순물 제어가 가능함을 확인하였다.

• 한국산업융합학회 논문집
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• 제4권1호
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• pp.27-34
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• 2001

Refining of powder particles and their dissolution into the Al matrix during mechanical alloying(MA) were investigated by using X-ray diffraction(XRD) transmission electron microscopy (TEM) functions of alloy composition, milling time and ball to powder ratio(BPR). It is found that Ti particles less than 20nm are observed in a dark field image of mechanically alloyed Al-10wt%Ti whose XHD pattern exhibits no Ti peak. The observed change of lattice constant of AI indicates that about 1 wt%Ti can he solved in Al after MA for a long time, independent of alloy composition, milling time and BPR, suggesting that most of Ti particles arc retained in the Al matrix. It is concluded that the disappearance of XRD peaks in mechanically alloyed Al-10wt%Ti is not simply attributable to the dissolution of Ti into Al, but associated mainly with extreme refining and/or heavy straining of Ti Particles.

• 펄프종이기술
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• 제32권2호
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• pp.35-39
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• 2000

Refining is very important process of fibers treatment for proper paper properties. An extent of refining is usually measured by freeness, although freeness gives complicated meanings. One of a direct way of studying the refining effects on pulp fibers is making photomicrographs of beaten fibers. The conventional microscopy like light microscopy(LM) and scanning electron microscopy(SEM) require to preserve the wet structure of pulp fibers morphologically since most of papermaking process is carried out almost entirely in water. Recently developed microscopy, especially confocal laser scanning microscopy(CLSM), offers the possibility of examining fully hydrated pulp fibers. Cross-sectional images of wet pulp fibers are also generated using optical sectioning by CLSM and image analysis in order to verify and quantify the extent of fiber wall swelling indicating the internal fibrillation. At low beating load such as 2.5 kgf, in the same freeness, breaking length is higher than that of high beating load such as 5.6 kgf. fiber wall thickness at low beating load is greater than that at high beating load. This result is accounted for the fact that internal fibrillation in the low beating load was high.

• 한국인쇄학회지
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• 제26권1호
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• pp.113-124
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• 2008

Viscosity of cellulose pulp was greatly decreased with endo-xylanase treatment but tiny decreased with exo-xylanase treatment. Change of freeness was greatly influenced with exo-xylanase treatment. The first stage of refining(5,000 revolution), freeness was greatly decreased with exo-xylanase treatment. After middle stage of refining(10,000 revolution) change of freeness was similar to endo-xylanase treatment. WRV(water retention value) was more effective exo-xylanas than endo-xylanase treatment. Interfiber bonding of cellulose fiber was disintegrated with exo-xylanse treatment.

• 펄프종이기술
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• 제38권3호
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• pp.7-12
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• 2006

The pore structure of paper was modified by the application of the blending of pulp, refining, and filler particle size and ash content. It was conformed that the reflectivity of paper can be modified by the combination of the above parameters. It was also found that the change of reflectivity of paper was greatly dependent on the pore structure, such as average pore size, pore size distribution and porosity. The average pore size was decreased with addition of HwBKP, but the smallest average pore size was obtained from the addition of 80% HwBKP Refining of pulp decreased both average pore size and the reflectivity of paper. The pore size distribution of filled paper can be varied by the combination of filler particle size and ash content

• 한국주조공학회지
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• 제23권2호
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• pp.63-68
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• 2003

Al-Ti-C grain refiner form a relatively new alternative to the existing class of Al-Ti-B type grain refiners for achieving fine equiaxed structures in aluminum alloys during casting and solidification. The present study was carried out to investigate the influence of Al-Ti-C master alloys on the grain structure of Al-7Si alloys. The present study also investigates the relationship between grain refining efficiency and concentrations of Fe and Si in hypo-eutectic Al-Si alloys using Al-3Ti-0.13C master alloys. It is found that several parameters affect significantly the grain refining performance in silumin alloys. The present study reports the influence of various parameters such as alloy content, master alloy addition level, melt holding time and superheat on the grain refining efficiency in Al-7Si alloys.