• Title/Summary/Keyword: 입도조성

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The Changing Process of the Tidal Landforms in Hampyeung Bay, Southwest Korea (함평만의 간석지 해안지형의 변화)

  • KIM, Nam-Shin;LEE, Min-Boo
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.4
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    • pp.223-233
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    • 2011
  • The aims of this study is about distribution characteristics of tidal coastal landforms, and that changing process in the Hampyeung Bay, which has a semi-enclosed bay like basin shape without inflow of stream, the mouth of open sea is narrow and forms with wide ends toward inland sea. The source of deposits are moved materials by tidal currents and from coastal slopes. Main landform elements of study area consist of tidal flat, tidal channels, intertidal sand bar, sea cliffs, and sea terrace. Tidal flats is classified with mud flat and mixed flat by grain size composition. Mud flats have developed at the shoreline area that tidal flat is closed to the continuity of gentle slope, and mixed flat developed at the foot of the sea cliffs and sea terraces. Quaternary deposits were identified in the coastal materials sedimented by the sea-level change. According to the analysis of grain size composition during last ten years, sands and silt has increased 2% and 6% respectively, clay has been decreased by 9%. The concaved tidal flats are colonized by salt plants. Areal changes of salt plants expanded near four times from 2.4km2 at the year 2001 to 9.3km2 at the year 2009. During the same periods, mean grain size became coarser from 6.5φ to 4.5φ at the salt plants area.

Comprehensive Assessment of Thermal Behavior of Heavy Metal Elements in Coal (석탄에 존재하는 중금속원소들의 고온거동에 관한 고찰)

  • 김형택;최병철;권혁보
    • Journal of Energy Engineering
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    • v.8 no.4
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    • pp.499-504
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    • 1999
  • 본 논고에서는 석탄의 화학조성, 입도 및 광물질 종류들에 따라 중금속 선분들의 고온 거동을 해석하여 대규모 석탄화력발전소의 중금속화합물 배출규제기준결정과 관련된 기초자료를 제공하고자 시도하였다. 먼저 , Sb. Ca, Pb, Ni, As, Cr, Mg, Se, Be Co, Hg,Mn, Cd Ti, Zn 등 원소들의 휘발성을 석탄에 포함된 광물질의 고온거동을 조사하여 분석한 결과 중금속물질 배출정도는 광물질들의 고온상 기체/고체 분포 여부 및 광물질들의 고온에서의 변이 과정과 밀접한 관계가있는 것으로 인식되었다. 또한 , 반응후 중금속물질들의 비산재와 슬랙에의 존재분포를 입도별로 해석하였으며, 그 결과는 EF enrichment factor를 이용하여 해석하였다.

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Recycling of Fe-Ni Waste Solution by Spray Pyrolysis Process (분무열분해 공정에 의한 Fe-Ni 계 폐액의 리싸이클링)

  • 유재근
    • Proceedings of the KAIS Fall Conference
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    • 2003.06a
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    • pp.95-97
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    • 2003
  • 본 연구에서는 새도우마스크 제조공정에서 발생되는 Fe-Ni 계 폐산 용액에 Ni 성분을 용해시킨 복합 산용액을 원료용액으로 사용하여 분무열분해법에 의해 입도분포 및 조성이 균일하며, 입자형태가 구상이면서 평균입도가 100nm 이하인 Ni-ferrite 나노 분말을 제조하며 원료용액의 유입속도, nozzle tip 크기 및 공기압력의 반응조건 변화에 따른 생성분말의 특성 변화를 파악하였다.

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Antifoaming Properties for Aliphatic Antifoamer Formula (지방족 소포제 조성물의 소포특성)

  • Jeong, Noh-Hee;Park, Gor-Soon;Park, Joon-Suk;Nam, Ki-Dae
    • Journal of the Korean Applied Science and Technology
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    • v.16 no.2
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    • pp.147-153
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    • 1999
  • As main components of antifoamers, we were used fatty alcohols, fatty acid and fatty acid esters. Then the antifoaming properties on the particle size distribution, temperature and concentration for antifoamers was measured by Air Injection Method of ASTM under 1L/min air flow rate condition, and was measured surface tensions and emulsifying power of antifoamers. The antifoaming properties on the particle size distribution of antifoamers showed excellent antifoaming properties in the range of emulsion particle size from 5.5 to 6.8${\mu}m$. Surface tensions on the $10^{-2}$wt% aqueous solution of antifoamers was $33{\sim}34$ mN/m. And emulsifying power of fatty alcohol antifoamers showed good.

Particle Size Characteristics with the Specification of Yeongdong Illite Powder Products (영동 일라이트 분말 제품의 규격에 따른 입도 특성)

  • EunJi Baek;Yu Na Lee;Eun Jeong Kim;Youngseuk Keehm;Hyun Na Kim
    • Korean Journal of Mineralogy and Petrology
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    • v.36 no.4
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    • pp.345-353
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    • 2023
  • This study aimed to investigate the differences in the commercial powder products of the Yeongdong illite based on sales specifications, specifically examining the mineralogical composition, particle size, and chemical composition according to mesh size. The goal was to understand the characteristics of illite powder products and utilize them as a mineralogical database for exploring various applications. Commercial illite powder samples obtained from two mines were subjected to various experiments, including X-ray diffraction (XRD) analysis, laser diffraction particle size analysis, and scanning electron microscopy analysis, X-ray fluorescence analysis. The XRD analysis revealed that the illite powder products from the two mines mainly consisted of illite/muscovite, quartz, and feldspar, indicating similar constituent minerals matching with those of ores for each mine. Laser diffraction particle size analysis indicated the difference in particle size distribution depending on the product specifications, with particle size uniformity tending to increase with increasing mesh sizes. Scanning electron microscopy analysis showed variations in particle shape and size based on specifications. The size of illite particles did not vary significantly with product specifications, with noticeable changes observed mainly in the particle sizes of quartz and feldspar. Furthermore, although there were some differences in chemical composition among the samples from different mines, no significant variations were observed according to specifications. Based on these results, when considering the application of commercial illite powder, it is essential to carefully select it with the consideration of its specifications to account for characteristic variations. The findings of this study present support the great potential of various application fields of commercial illite powder, contributing to industrial utilization and the development of new technologies.

Variation of strength of soil matrix with artificially manipulating particle distribution of granular soil (인위적 입도조정에 따른 지반의 강도특성 변화)

  • Moon, Jun-Ho;Xin, Zhen-Hua;Kim, Gab-Boo;Moon, Sun-Mi;Kim, Young-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.56-62
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    • 2018
  • In this study, an artificially formed Gap graded soil, designed to increase its shear strength, was analyzed to determine the strength parameters through direct shear tests. Uniform and fine grain size samples were compared to the Gap graded soil to investigate the increase in the shear strength. Plate loading tests were conducted using 13mm and 19mm aggregates to confirm the reproducibility of the strength enhanced samples for site application. This test confirmed that the particle size ratio and the internal friction angle are correlated to the shear strength, and the shear resistance angle significantly increased in the specific particle size ratio range. The calculation of the ultimate bearing capacity by the plate load test demonstrated that the grain size adjustment method greatly influences the strength increase rate. Therefore, the findings were verified and it was confirmed that a high shear strength is achievable despite the existence of a poor particle size distribution.

FeO, $TiH_2$, Carbon 원료분말을 이용한 Fe-TiC 나노 복합분말 제조 및 소결

  • An, Gi-Bong;Kim, Ji-Sun
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.10a
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    • pp.26-26
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    • 2011
  • Fe계 TiC 합금은 미량의 합금원소를 첨가시켜 경화능, 내식성, 내마모성 성질을 개선한 특수 공구용 재료로서 현재 절삭, 내마모성, 광산, 금형재료 등의 분야에 널리 사용되고 있다. 금속과 세라믹의 복합재료인 초경합금은 비열처리용 공구강으로 WC, TiC 등의 4, 5, 6족 금속탄화물에 Co, Ni, Fe등의 철족이 결합금속으로 소결한 복합재료로 WC-Co계 초경합금이 주종을 이루고 있으나, 전략 소재로서 고가인 Co 원료를 대체하기 위한 재료로서 초경재료의 고경도와 공구강의 경제성 및 가공성의 장점을 이용한 Fe-TiC계 초경합금의 연구가 다양하게 진행되고 있다. 본 연구에서는 Fe기지에 서브마이크론 크기의 미세한 TiC 입자가 균일하게 분산된 Fe-TiC 복합분말을 경제적으로 제조하기 위해 순수한 Fe, Ti 원료분말에 비해 단가가 낮고 미세 분쇄가 용이한 FeO, $TiH_2$ 분말을 고에너지 밀링 후 반응 열처리 시키는 유사 기계화학적 공정을 시도하였다. 조성비 Fe-30wt%TiC 복합분말을 제조하기위해 마이크론(micron) 크기의 FeO, $TiH_2$, C 분말을 사용하였고, 1단계로 FeO와 C을 고에너지 밀링으로 혼합 후 반응시켜 환원시키는 공정과 2단계로 이렇게 환원된 분말과 TiH2를 고에너지 밀링으로 다시 혼합, 분쇄한 후 반응열처리 하는 두 단계 공정을 사용하였다. FeO의 환원 단계에서는 $700{\sim}1,000^{\circ}C$ 온도 범위에서 1시간 유지하였고, 고에너지 밀링 시 밀링시간, 회전속도를 변수로 두고 실험하였다. 환원된 분말은 수평관상로를 이용해 아르곤분위기에서 $1,000{\sim}1300^{\circ}C$까지 1시간 유지하여 반응열처리시켜 Fe-TiC 복합분말을 제조하였다. 준비된 복합분말을 XRD와 FE-SEM, EDS, 입도분석기 (LPSA) 등을 이용해 분말의 형태와 특성, 상, 조성, 입도, 분산도 등을 조사하였다. 제조된 Fe-TiC 나노복합분말을 방전플라즈마소결(SPS) 과 상압소결 실험을 진행하였다. Fe-TiC 복합분말 제조공정의 첫 번째 단계인 FeO의 환원반응은 $800^{\circ}C$이상의 온도에서 Fe로 환원이 진행됨을 확인하였다. 두 번째 단계인 반응열처리공정에서는 $1,000^{\circ}C$ 이상에서 TiC가 형성됨을 XRD 상분석을 통해 확인할 수 있었고, $1,100^{\circ}C$ 이상의 온도에서 반응열처리를 했을 때 XRD 분석결과와 산소 조성 분석 결과로부터 반응의 완결성과 순도에서 최적 온도 조건임을 확인하였다. 온도를 $1,300^{\circ}C$로 증가시킬 경우 반응의 완결성에 큰 변화가 없는 반면 분말입자간의 목형성이 일어나 가소결 되는 것을 FE-SEM을 통해 관찰하였다. 또한 최적조건으로 제조된 Fe-TiC 복합분말의 입도분석과 FE-SEM/EDS 관찰/분석을 시행한 결과 평균 입도 0.6 ${\mu}m$의 미세한 Fe-TiC 복합분말 내에 Fe분말 주변과 내부에 나노크기의 TiC입자가 균일하게 분산되어 존재하는 것을 확인하였다.

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Compositional Characterization Analysis of Wall Soils Excavated in Poongnatoseong Earthen Castle, Seoul (풍납토성 성벽 토양의 성분 특성 연구)

  • Seo, Min Seok;Lee, Han Hyeong;Hu, Jun Soo;Kim, Soo Keung;Yoo, Young Mi;Lee, Seong Jun
    • Korean Journal of Heritage: History & Science
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    • v.45 no.4
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    • pp.114-125
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    • 2012
  • The purpose of this study is to analysis chromaticity, granulometry, main chemical composition and mineral crystal structure of wall soils excavated from Poongnatoseong Earthen Castle using color reader, XRD, particla size analyzer. The analysed soils of Poongnatoseong Earthen Castle were yellowish brown and isabella. All samples were sands or sands including silty soil(SW~SC) and showed similar granulometry, chemical composition and mineral crystal structure, which were characteristics of construction materials suitable for modern road or airstrip. As resulting in comparison with 4 factors from chromaticity, granulometry, main chemical composition and mineral crystal structure, we decided that the control soils(PNS) near by Poongnatoseong Earthen Castle were not to be used for the castle wall construction We presumed that there was a huge soil distribution area for the wall construction around Poongnatoseong Earthen Castle. For further study, we will make a comparison analysis all kinds of soil characteristics. And then we can understand correctly about wall soils producing area, construction method, repair method and time of Poongnatoseong Earthen Castle.

Optimization of Polymer Composite Properties Using a Red Clay (황토를 이용한 고분자 복합수지 물성 최적화)

  • Seo, Kyoung-Won;Ji, Ju-Hyeon;Peng, Mei-Mei;Lee, Joo-Bo;Jang, Hyun-Tae
    • Proceedings of the KAIS Fall Conference
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    • 2011.05a
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    • pp.332-335
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    • 2011
  • 원적외선, 음이온 방출과 항균, 탈취, 난연등의 효과를 가지는 황토를 합성수지와 혼합하여 복합소재를 연구하여 환경 친화적인 특징과 원적외선, 음이온의 방출을 이룰 수 있는 복합소재 조성을 연구하였다. PP는 MI가 2~60이고, TPE로 Ethylene계을 사용하였으며, 황토와 PP의 혼련을 도와주기 위하여 MA-g-PP를 첨가하였고, 활제, 분산제 및 산화방지제를 첨가하여 compounding 하였다. 또한 황토의 종류에따라 적황토, 호황토, 홍토, 백토, 흑토등으로 구분되고, 각각의 황토 마다 다양한 종류의 입도를 가지고 있으며, 또한 환경 친화적이며 난연성을 부여하기 위하여 다양한 조성으로 compounding 하였다, 황토의 종류에 따른 복합재료의 물성으로부터 기계적 특성치, 원적외선 방사율, 난연성등을 확인하고, 친환경 난연 복합소재 기술을 연구하였다. 적황토의 경우 황토의 함량이 많을수록 인장강도는 작아지는 경향을 나타냈으며, 입도가 작을수록 인장강도가 커지는 경향을 나타냈다. 파단신율의 경우 적황토(#2000)에서 가장 양호하게 나타났으며, 굴곡강도, 충격강도의 경우 적황토(#5000)에서 MI 의 경우 적황토(#325)에서 양호하게 나타났다.

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Purification of Waste Acid and Manufacture of Complex Oxide and Mn-Ferrite Powder by Co-Roasting Process (폐산의 정제 기술 및 분무 배소법에 의한 복합 산화물과 Mn-Ferrite 분말의 제조)

  • 유재근;김정석;민병구;성낙일
    • Resources Recycling
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    • v.7 no.4
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    • pp.64-75
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    • 1998
  • The purpose of this study is to produce high putity composite powder composed of Fe-oxide, Mn-oxide and Mn-ferrite having superior homogencity in composition and particle size distribution by co-roasting process. Binary component metal (Fe, Mn) chloride solutions were produced by dissolving mill scale and ferro-mangancse alloy in hydrochloric acid. These chloride solutions contained the impurities such as SiO$_{2}$, P, Al, Ca and Na, which were originated from the Fe/Mn source materials. The neutralization and polymeric coagulant method were adoped to refine the hydrochloric liquor. When pH is far below the isoelectric point (pH 2-3), the SiO$_{2}$ was the most effectively reduced element, while other impurities remained unchanged. By increasing pH above 3, most of the impurities could be reduced effectively due to the coprecipitation reaction. The polymeric coagulants such as poly vinyl alcohol, resin amine and ammonium molybdate were found to have no effect on the spray roaster designed by the authors. The produced oxide powders were confirmed to be mixtures of Fe-oxide, Mn-oxide and mn-ferrite. the powders were homogeneously mixed and the particle size increased sleeply with increasing co-roasting temperature.

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