생활폐기물(生活廢棄物) 소각(燒却) 바닥재의 자력선별(磁力選別)에 따른 ferrous material의 분리(分離) 특성(特性)

엄남일,한기천,유광석,조희찬,안지환,Um, Nam-Il,Han, Gi-Chun,You, Kwang-Suk,Cho, Hee-Chan,Ahn, Ji-Whan 한국자원리싸이클링학회 2007 資源 리싸이클링 Vol.16 No.3

도심지에서 발생하는 생활폐기물들은 재활용 가능한 목재나 iron 등을 분리시킨 후 소각장으로 보내지기 때문에 자기류나 유리류 그리고 가장 많은 양을 차지하고 있는 가연성 물질로 존재하게 된다. 하지만 소각 전 분리 공정에도 불구하고 생활폐기물에서의 iron의 함유량은 약 $3{\sim}11%$에 달하고 있다. 이러한 iron은 소각로에서 소각 처리될 경우 약 $1000^{\circ}C$의 온도(로의 내부 온도)에서 산화반응에 의해 표면에 산화물 층을 형성하게 된다. 소각된 바닥재는 water-cooling냉각 처리를 통해 냉각되며 물과 접촉한 iron 표면의 산화물 층은 심한 붕괴가 일어나 부식작용이 더욱 활발히 일어나며 많은 양의 ferrous material($Fe_3O_4,\;Fe_2O_3,\;FeS_2$)을 생성하게 된다. 이러한 iron과 ferrous material은 산화 환원 작용에 의해 부피변화를 일으키기 때문에 시멘트 골재 등으로의 재활용 시 많은 문제점을 일으킬 수 있다. 따라서 본 연구에서는 소각 바닥재를 이용하여 각 입도별 자력선별에 따른 ferrous material의 분리 특성에 대해 연구하였다. 그 결과 전체 바닥재의 약 18.7%(ferrous product; $Fe_3O_4,\;Fe_2O_3,\;FeS_2$, iron)가 자력선별(자력세기:3800gauss)에 의해 분리 되었으며 1.18mm이상의 입도에서 전체 ferrous product의 87.7%가 분포하였다. iron의 경우 전체 바닥재의 약 3.8%의 함유량을 보였으며 1.18mm이상의 입도에서 전체 iron의 99%이상이 존재하였다. The bottom ash of municipal solid waste incineration generated during incineration of municipal solid waste in metropolitan area consists of ceramics, glasses, ferrous materials, combustible materials and food waste and so on. Although the ferrous material was separated by the magnetic separation before the incineration process, of which content accounts for about $3{\sim}11%$ in bottom ash. The formation of a $Fe_3O_4-Fe_2O_3$ double layer(similar to pure Fe) on the iron surface was found during air-annealing in the incinerator at $1000^{\circ}C$. A strong thermal shock, such as that takes place during water-cooling of bottom ash, leads to the breakdown of this oxidation layer, facilitating the degradation of ferrous metals and the formation of corrosion products and it existed as $Fe_2O_3,\;Fe_3O_4\;and\;FeS_2$. So, many problems could occur in the use of bottom ash as an aggregate substitutes in construction field. Therefore, in this study, the separation of ferrous materials from municipal solid waste incineration bottom ash was investigated. In the result, the ferrous product(such as $Fe_2O_3,\;Fe_3O_4,\;FeS_2$ and iron) by magnetic separator at 3800 gauss per total bottom ash(w/w.%) accounted for about 18.7%, and 87.7% of the ferrous product was in the size over 1.18 mm. Also the iron per total bottom ash accounted for about 3.8% and the majority of it was in the size over 1.18 mm.

Acidithiobacillus ferrooxidans와 Acidithiobacillus thiooxidans를 활용한 고농도 비소 함유 광석 내 중금속 용출 거동 연구

김가희,김리나,김관호,유광석,Kim, Gahee,Kim, Rina,Kim, Kwanho,You, Kwang-suk 한국자원리싸이클링학회 2021 資源 리싸이클링 Vol.30 No.2

To investigate the potential for leaching of heavy metals by bacteria from ores stacked on actual mining sites, leaching tests of a complex metallic ore (Pb-Zn-As ore) were conducted over 60 days using acidophile bacteria Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans under initial acidic conditions. Initially, a small amount of heavy metals was leached due to the initial acidic conditions. After 20 days, when A. thiooxidans in the reactor was adapted to the ore, the amount of leached heavy metals rapidly increased; the concentrations of leached arsenic, iron, and zinc reached a maximum of 2800, 3700, and 2500 mg/L, respectively. On the other hand, in the presence of A. ferrooxidans or in the control test without bacteria, heavy metals, except zinc, were barely detected in leaching. Through this study, it was confirmed that (i) bacteria could leach heavy metals at mining sites under acidic conditions and (ii) leaching of heavy metals from a high arsenic-containing ore by A. thiooxidans was more significant than that by A. ferrooxidans.

생활폐기물(生活廢棄物) 소각(燒却) 바닥재의 자력선별(磁力選別)에 따른 크롬과 니켈의 거동(擧動)

안지환,엄남일,조계홍,오명환,유광석,한기천,조희찬,한춘,김병곤,Ahn, Ji-Whan,Um, Nam-Il,Cho, Kye-Hong,Oh, Myung-Hwan,You, Kwang-Suk,Han, Gi-Chun,Cho, Hee-Chan,Han, Choon,Kim, Byong-Gon 한국자원리싸이클링학회 2007 資源 리싸이클링 Vol.16 No.6

생활 폐기물은 대부분 유리류와 자기류뿐만 아니라 많은 양의 iron을 함유하고 있으며 약 $3{\sim}11%$에 달한다. 대부분의 iron은 Ni-Fe와 Ni-Cr-Fe 같은 합금으로 존재하거나, 부식방지와 광택을 위해 Ni와 Cr로 도금된 iron으로 존재하고 있기 때문에 소각로에서 소각될 경우 철 재품 표면에 심하게 파손된 $Fe_3O_4$층과 함께 $NiFe_2O_4$와 FeCr_2O_4$을 형성하게 되어 바닥재에 존재하게 되어 중금속산화물 층을 형성시킬 수 있다. iron은 자력이 매우 강해 자력선별에 의해 쉽게 선별되며 이러한 효과로 인해 중금속 산화물의 선별까지 얻을 수 있다. 또한 바닥재는 다양한 Ni와 Cr 산화물들을 함유하고 있으며, Ni와 Cr은 강자성을 띈 물질이기 때문에 자력선별에 의해 큰 영향을 받을 수 있다. 따라서 자력선별에 따른 Ni와 Cr의 거동에 대해 조사하였으며 그 밖의 다른 중금속(Cu, Pb, Cd, As)들의 거동 또한 확인해 보았다. 그 결과 Ni와 Cr은 약 $45{\sim}50%$의 선별율을 보였으며, Cu와 Pb는 $15{\sim}20%$을 나타냈다. 또한 자력선별 전과 후의 바닥재에 대해 Ni와 Cr의 용출량을 확인해본 결과 자력선별 후 바닥재의 용출량이 더 낮음을 확인할 수 있었다. Although the ferrous material was separated by the magnetic separation before the incineration process, the municipal solid waste incineration bottom ash generated during incinerator in metropolitan area consists of many iron products which account for about $3{\sim}11%$ as well as ceramics and glasses. The formation of $NiFe_2O_4$ and $FeCr_2O_4$ with a $Fe_3O_4-Fe_2O_3$ (similar to pure Fe) on the surface of iron product was found during air-annealing in the incinerator at $1000^{\circ}C$, because Ni and Cr has a chemical attraction about iron is using to coat with Ni and Cr metals for poish or to prevent corrosion. Therefore, Fe-Ni Cr oxide can be formed on durface of the iron product and it can be separated from bottom ash through the magnetic separation. So, in this study, the separation ratio of heavy metals as magnetic separation and mineralogical formation of Fe-ion(heavy metal) in ferrous metals corroded were investigated. As the result, the separation ratio of Ni and Cr based on particle sizes accounted for about $45{\sim}50%$, and Cu and Pb accounted for below 20%. Also, the leaching concentration of Ni and Cr in bottom ash separated by magnetic separation was lower than that in fresh bottom ash.

수동 변속기용 동기기구의 마찰력과 마찰재의 영향 분석

조용이(Yong Ee Cho),유광석(Kwang suk You),윤중현(Jung hyun Yoon) 한국생산제조학회 2006 한국생산제조학회지 Vol.15 No.2

A driver’s feelings of transmission serve as a basis to judge not only the transmission but also the entire automobile that he or she drives. The importance of transmission feelings is increasing daily because of driver’s desire for increased torque and other improved functions. In order to accommodate such desire of drivers, new friction materials have been developed. The study in this report compared the affects of such materials and the force for transmission theoretically and empirically. By doing so, the study attempted to establish basic references for computation of capacity and other factors to be determined at the time of design of synchronizer system.

폐신문지(廢新聞紙)(ONP)로부터 부유선별(浮遊選別)을 이용한 잉크분리(分離)시 초음파처리(超音波處理) 효과(效果)

임광일,황인성,김정운,유광석,안지환,한춘,Lim, Gwang Il,Hwang, In Sung,Kim, Joung Woon,You, Kwang Suk,Ahn, Ji Whan,Han, Choon 한국자원리싸이클링학회 2012 資源 리싸이클링 Vol.21 No.5

재생률이 높은 폐신문지(old newspaper, ONP)를 부유선별법을 이용하여 탈묵을 진행하였을 시, 해리시간, 초음파처리에 따른 백색도, 잔류잉크농도(effective residual ink concentration, ERIC), 수율의 효과를 규명하였다. 또한 부유선별시 pH, 포수제에 따른 백색도, ERIC과 수율의 효과도 규명하였다. 해리시간이 증가할수록 백색도와 ERIC이 증가함을 보였으나 수율의 차이는 없었다. 해리시간이 30분일 때 백색도 58% ERIC 182.9 ppm이였고, 해리를 더 진행하더라도 백색도의 증가를 볼 수 없었다. 단 해리 된 ONP를 초음파발생장치를 이용하여 초음파처리를 했을 경우 단 2분의 해리시간으로도 58%이상의 백색도를 얻을 수 있었다. 초음파처리를 20분간하고, pH 11에서 포수제로 등유을 사용했을 때 백색도가 59.32%로 가장 높았다. In this study, the sonication method was applied to remove ink from old newspaper(ONP) using flotation. Results indicated increased whiteness and effective residual ink concentration (ERIC) with longer disintegration. Therefore 58% of whiteness and 182.9 ppm ERIC were obtained for 30 minutes of disintegration time without the change in yield. Longer disintegration than 30 minutes had no effects on whiteness without the application of ultra-sonication. On the other hand, higher than 58% of whiteness was achieved in 2 minutes of disintegration when the ultra-sonication was applied. The highest whiteness (59.32 %) was obtained by applying sonication for 20 minutes and froth flotation with kerosene as a collector under the alkaline condition (pH 11).

공기와 활성탄 병용에 의한 용액 중 고농도 3가 비소의 산화-침전 거동 연구

김리나,김가희,김관호,유광석,Kim, Rina,Kim, Gahee,Kim, Kwanho,You, Kwang-suk 한국자원리싸이클링학회 2021 資源 리싸이클링 Vol.30 No.4

Arsenic (As) oxidation followed by precipitation from a high-As(III)-containing leaching solution derived from a sulfidic ore was investigated in this study to remove aqueous As from the solution using activated carbon (AC) with air injection as an oxidant. To obtain the initial leaching solution, a domestic sulfidic ore was leached in a sulfuric acid solution at pH 1 and 50℃ for 95 h, and approximately 7 g/L of Fe and 3 g/L of As were leached out. To determine the effect of the oxidative reaction utilizing AC with air injection, the leaching solution was tested under the following five oxidative conditions at an initial pH of 1 and 90℃ for 72 h: air-only injection; air injection with 1, 5, and 10 w/v% of AC addition; and H₂O₂ addition. The tests in the presence of both air and AC revealed that the oxidation kinetics and As removal were improved by the reaction between the metallic species and the surface group formed on the AC surface. In addition, the greater the amount of AC added, the better was the reaction efficiency, removing 93-94% of As with more than 5 w/v% of AC addition. Finally, X-ray diffraction analysis confirmed that the precipitate formed from the oxidative reaction was scorodite (FeAsO₄·2H₂O).

현탁제 제조공정에서 발생된 거품이 완제품 주성분 함량에 미치는 영향

강신국(Shin Kook Kang),송민섭(Min Sub Song),신경오(Kyung Oh Shin),유광석(Kwang Suk You),한성수(Seong Soo Han),홍진태(Jin Tae Hong) 대한약학회 2022 약학회지 Vol.66 No.1

This study aimed to investigate the influence of foam generated in the pharmaceutical suspension manufacturing process on finished products’ active pharmaceutical ingredient (API) contents. In particular, we aimed to evaluate the possibility of having a higher API content in pharmaceutical suspensions containing a large amount of foam. We also investigated content analysis results based on prior studies related to the attachment of solid particles to bubbles. Each test tube was agitated at 1,200 rpm for 60 min to generate bubbles. To measure the API content, samples were collected from each layer (lower, middle, upper, foam). The API content analysis results were further analyzed by general properties (pH and density), surface hydrophobicity (contact angle), and morphological properties (particle size and shape). The API content in five out of seven pharmaceutical suspensions increased toward the upper layer, and the API concentration of the foam layer was the highest. The other two suspensions showed an opposite trend. The contact angle of API particles of products with an increased toward the upper layer was greater than 62o, the particle size exceeded 4μm, and the particles were needle-shaped and had angular fragments. Our findings indicate that API particles are highly concentrated in the foam generated during the manufacturing process depending on various properties, including surface hydrophobicity, particle size, and shape. Therefore, improvements in formulations and the manufacturing process of pharmaceutical suspensions such as foam suppression or breakage rather than foam removal from the intermediate products are required.

생활폐기물 소각 바닥재의 accelerated carbonation처리에 의한 CO₂ 저감 연구

안지환(Ahn Ji-Whan),한기천(Han Gi-Chun),유광석(You Kwang-Suk),조희찬(Cho Hee-Chan) 한국에너지학회 2008 한국에너지공학회 학술발표회 Vol.2008 No.-