• 한국건축시공학회지
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• 제17권6호
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• pp.517-525
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• 2017

레드머드(Red mud)는 보오크사이트 원광석으로부터 수산화알루미늄($Al(OH)_3$) 및 산화알루미늄($Al_2O_3$)을 제조하는 공정에서 발생되는 산업부산물로 Bayer Process를 통하여 함수율 50%의 슬러지 상태로 국내에서 연간 약 30만톤이 발생되고 있다. 본 논문에서는 함수율 50%의 레드머드 슬러지를 가열 공정없이 건설산업 현장에 사용할 수 있도록 적정 혼합수 및 첨가제를 사용하여 액상화하고 점도, 입도, 침전지수와 같은 분산특성을 검토하였다. 본 논문의 범위에 한정하여 액상화 레드머드의 안정적인 분산을 위해서는 초기 점도를 2000cP에서 8000cP을 적용하고 목표 침전지수를 20%이하로 설정하는 것이 타당할 것으로 사료된다.

• 환경위생공학
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• 제15권1호
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• pp.62-68
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• 2000

This study was investigated to the recovery of alumina from the first calcined waste pottery using alkaline sintering. This study was based on calcination result of a commercial ${\alpha}-Al2_O_3$ with NaOH powder. $NaAlO_2$ was formed by calcination of ${\alpha}-Al_2O_3$ with NaOH and conversion of $NaAlO_2$ from ${\alpha}-Al_2O_3$ was 91.4% at calcination condition ; weight ritio of $NaOH/{\alpha}-Al2_O_3$ 1.5, $800^{\circ}C$, and 90min. The first calcined waste porrery from the manufacturing Procedure of H Ltd. was grinded to 170/270mesh by a ball mill and calcined over $500^{\circ}C$ with NaOH powder. The calcined sample was dissolved in $25^{\circ}C$ water and sodiumaluminosilicate solid was formed. After filtration, the contained aluminum was leached out by dissolving sodiumaluminosilicate solid in 1N HCl. We estimated the efficiency of Al extraction from waste pottery by ICP analysis and NaOH was added to the filtrate and then aluminum compound was precipitated with $Al(OH)_3$ and recovered. The investigation was carried out with the variables ; the calcination temperature($500-900^{\circ}C$), the calcination time(30~90min), and the weight ratio of NaOH/waste pottery(0.5~1.5). The treatment efficiency of the waste pottery and the recovery of Al as 97.9%, 91.9% were obtained under the optimum conditions as followed ; the weight ratio of NaOH/waste pottery was 1.5 and the calcination conditions were $900^{\circ}C$ and 60min.

• 자원리싸이클링
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• 제19권4호
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• pp.13-18
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• 2010

세계 각국은 폐기물의 발생과 이의 처리를 위해 많은 노력을 기울이고 있다. 폐기물 중 특히 폐알칼리는 부식성으로 인해 환경오염에 대한 위험성이 높기 때문에 효율적 관리를 통해 재활용되어야 하며, 이를 위해 재활용 생성물에 대한 품질기준에 따라 관리될 필요가 있다. 그러나 현재 품질관리가 필요한 대상물질에 대한 국내 자료가 전혀 없다. 따라서 본 연구에서는 최근 5년간의 자료 분석과 현장방문을 통해 체계적인 관리가 필요한 폐알칼리 재활용 대상물질을 선정하였다. 그 결과 재활용 대상 주요물질은 가성소다, 황산알루미늄, 폴리염화알루미늄인 것으로 나타났다. 장차 국가적 차원에서 이들 주요물질에 대한 적절한 관리체계가 구축될 필요가 있는 것으로 판단되며, 이를 통하여 폐기물의 자원화 뿐 아니라 우리 주변의 환경오염을 막는 긍정적인 효과가 있을 것으로 기대된다.

• 한국토양비료학회지
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• 제45권6호
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• pp.925-927
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• 2012

산성화된 토양에서 생육하는 오이가 황백화 되면서 시드는 증상이 발생하여 현장에서 토양을 검사하여 진단하고 현장에서 토양 pH를 측정한 결과 4.2로 매우 낮은 강산성이었고, 실험실에서 분석한 결과 4.5로 나타났다. 토양을 풍건하여 토양 pH를 측정한 결과 4.5로 강산성이었다. 그래서 토양을 포화추출법으로 용액을 채취하여 분석한 결과 Al이 해리되어 나오고 있었고 식물체를 분석한 결과 Al이 고농도로 흡수되어 있었으며 질소와 Ca의 함량이 매우 낮았다. 현장에서 pH를 교정하기 위하여 소석회 포화액과 탄산칼슘을 처리한 결과 pH를 6.5로 조절할 수 있는 소석회 450 mL $plant^{-1}$를 처리한 주에서 어린 잎부터 정상적인 생육을 하였다. 이 결과로부터 강한 산성토양에서 나타난 오이의 황백화 증상은 Al이 해리되어 식물체로 과잉 흡수되고 이로 인하여 질소와 칼슘의 부족으로 야기된 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3553-3558
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• 2014

The reduced graphene oxide(rGO)/aluminum phosphate($AlPO_4$)-coated $LiMn_{1.5}Ni_{0.5}O_4$ (LMNO) cathode material has been developed by hydroxide precursor method for LMNO and by a facile solution based process for the coating with GO/$AlPO_4$ on the surface of LMNO, followed by annealing process. The amount of $AlPO_4$ has been varied from 0.5 wt % to 1.0 wt %, while the amount of rGO is maintained at 1.0 wt %. The samples have been characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The rGO/$AlPO_4$-coated LMNO electrodes exhibit better cyclic performance compared to that of pristine LMNO electrode. Specifically, rGO(1%)/$AlPO_4$(0.5%)- and rGO(1%)/$AlPO_4$(1%)-coated electrodes deliver a discharge capacity of, respectively, $123mAhg^{-1}$ and $122mAhg^{-1}$ at C/6 rate, with a capacity retention of, respectively, 96% and 98% at 100 cycles. Furthermore, the surface-modified LMNO electrodes demonstrate higher-rate capability. The rGO(1%)/$AlPO_4$(0.5%)-coated LMNO electrode shows the highest rate performance demonstrating a capacity retention of 91% at 10 C rate. The enhanced electrochemical performance can be attributed to (1) the suppression of the direct contact of electrode surface with the electrolyte, resulting in side reactions with the electrolyte due to the high cut-off voltage, and (2) smaller surface resistance and charge transfer resistance, which is confirmed by total polarization resistance and electrochemical impedance spectroscopy.

• 상하수도학회지
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• 제25권4호
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• pp.479-488
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• 2011

Nanofiltration was performed with polyaluminium chloride solutions at different pH conditions to understand effects of inorganic compounds on aluminum hydrolysis products, i.e., three distinctive groups of aluminum species: polymeric Al at low pH; $Al(OH)_3$ at neutral pH; and ${Al(OH)_4}^-$ at high pH. The PACl solution was prepared to be approximately 4.0mM and adjusted to the designated pH. The influence of inorganic compounds on Al species fouling was investigated with 4.9mM $CaCl_2$ and 3.5mM $MgSO_4$ because $Ca^{2+}$, $Mg^{2+}$, $Cl^-$, ${SO_4}^{2-}$ are the most common inorganics in the drinking water. NF membrane fouling was measured by flux decline rate. The impact of $CaCl_2$ was not significant on the individual Al hydrolysis products fouling. However, the flux decline rate was drastically changed in the presence of $MgSO_4$. The concentration of particulate matters was considerably increased possibly due to interaction between Al species and ${SO_4}^{2-}$ where $MgSO_4$ was introduced. The particulates were accumulated on the membrane and enhanced the hydraulic resistance of the cake layer. In addition, conductivity removal of the membrane was decreased when Al-hydroxide was dominant due to reduction of membrane surface charge. The rejection of $Ca^{2+}$and $Mg^{2+}$ were considerably different, which implys that composition of inorganics paly a role on conductivity removal.

• 약학회지
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• 제40권1호
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• pp.25-35
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• 1996

Magaldrate. an antiacid was synthesized by reacting magnesium oxide, aluminum sulfate, and dried aluminum hydroxide gel. The optimum synthesis conditions based on the yield of t he product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of Magaldrate were as follows: Reaction temperature; 61~$85{\circ}C$, concentration of two reactants. Mgo and $Al(OH)_3$: 16~19.8%, molar concentration ratio of two reactants, [MgO]/[$Al(OH)_3$]; 4.2~5.0, temperature of washing water; 36~$41^{\circ}C$ and drying temperature of the product: 76~$80^{\circ}C$. Magaldrate was synthesized under the optimum synthesis conditions and identified by analyzing the chemical composition, and by differential scanning calorimetry and X-ray diffraction method. The Magaldrate sample synthesis under these conditions was used to prepare 15.6% Magaldrate original suspension which was utilized to make 13% Magaldrate suspension dispered in various concentrations of eight types of suspending agents. The acid-neutralizing capacity of 13% Magaldrate suspension dispersed in 0.25% suspending agents was examined by Rosset-Rice method. The maximum pH was reached within 1 minute in all suspension tested, and duration maintained between pH 3~5 was decreased in the order of Na alginate Na silicate(meta) Veegum HV pectin agar>Na>CMC>xanthan gum>bentonite. It was found that the hysteresis loop area was increased with temperature in the case of Riopan Plus and the addition of agar, whereas the area was decreased with temperature in the case of the addition of Na alginate and xanthan gum. 13% Magaldrate suspension tends to sediment by the addition of bentonite.

• 한국건설순환자원학회논문집
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• 제7권4호
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• pp.333-340
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• 2019

레드머드(Red mud)는 보크사이트(Bauxite)를 원료로 알루미나를 제조하는 공정에서 발생하는 산업부산물이다. 한국의 경우 베이어프로세스 공정을 통하여 Al2O3 1톤을 생산할 경우 함수율 50%의 레드머드가 약 2톤이 발생된다. 강알칼리성의 레드머드를 중화시킴으로서 재활용을 증대시킬 수 있고 보관 및 관리 측면에서 환경부하를 저감시킬 수 있다. 더욱이 재활용하기 위해 가열 및 분쇄 공정이 필요없는 액상화 레드머드에 대한 관심이 증대되고 있다. 따라서 본 논문에서는 질산 및 황산의 첨가량에 따른 액상화 레드머드의 pH 변화를 검토한 후 중화시킨 액상화 레드머드의 첨가량에 따른 시멘트 페이스트의 압축강도 특성을 비교 검토하였다. 그 결과 질산 및 황산으로 중화시킨 액상화 레드머드의 압축강도는 중화하지 않은 액상화 레드머드와 비교하여 상대적으로 높게 나타났다.

• 멤브레인
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• 제22권1호
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• pp.35-45
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• 2012

양극산화 알루미나(AAO)막의 나노 사이즈 미세공(세공 크기 20 nm, 10 nm 및 200 nm)을 주형으로 사용하여 전도성 고분자인 폴리피롤, 폴리아닐린 중합체 및 폴리피롤/폴리아닐린 공중합체 나노와이어를 제조하였다. 미세공 주형 내에서 전도성 고분자의 성장은 세공의 벽면을 따라 튜브 형태로서 성장하였으며, 3시간 이후에는 내부가 완전히 채워진 나노와이어가 형성되었다. AAO 막을 수산화나트륨 용액으로 퍼리하여 세공 내에 형성된 전도성 고분자 나노와이어를 회수 하였으며. 회수된 나노와이어�l 직경과 길이는 주형 막의 세공 형상과 일치하였다. 통상의 용액 중합법으로 제조된 전도성 고분자 분말과 비교하여 주형 합성법으로 제조된 전도성 고분자 나노와이어는 결정성과 열적 안정성이 향상되었으며, 전기 저항은 4~60% 감소하였다.

• Journal of Veterinary Science
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• 제24권1호
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• pp.15.1-15.13
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• 2023

Background: Inactivated vaccines are limited in preventing foot-and-mouth disease (FMD) due to safety problems. Recombinant virus-like particles (VLPs) are an excellent candidate for a novel vaccine for preventing FMD, given that VLPs have similar immunogenicity as natural viruses and are replication- and infection-incompetent. Objectives: The 3C protease and P1 polyprotein of type O FMD virus (FDMV) was expressed in yeast Hansenula polymorpha to generate self-resembling VLPs, and the potential of recombinant VLPs as an FMD vaccine was evaluated. Methods: BALB/c mice were immunized with recombinant purified VLPs using CpG oligodeoxynucleotide and aluminum hydroxide gel as an adjuvant. Cytokines and lymphocytes from serum and spleen were analyzed by enzyme-linked immunosorbent assay, enzyme-linked immunospot assay, and flow cytometry. Results: The VLPs of FMD were purified successfully from yeast protein with a diameter of approximately 25 nm. The immunization of mice showed that animals produced high levels of FMDV antibodies and a higher level of antibodies for a longer time. In addition, higher levels of interferon-γ and CD4⁺ T cells were observed in mice immunized with VLPs. Conclusions: The expression of VLPs of FMD in H. polymorpha provides a novel strategy for the generation of the FMDV vaccine.