• 제목/요약/키워드: Ash solution

검색결과 330건 처리시간 0.023초

알칼리 활성반응에 의한 Briquette ash의 강도 발현 특성 (The Compressive Strength Development of Briquette Ash by Alkali Activated Reaction)

  • 서명덕;이수정;박현혜;김윤종;이수옥;김택남;조성백
    • 한국재료학회지
    • /
    • 제18권9호
    • /
    • pp.463-469
    • /
    • 2008
  • Non-sintering cement was manufactured with briquette ash. Alkali activator for compression bodies used a NaOH solution. In order to apply alkali-activated briquette ash and the non-sintering cement to concrete, several experimental studies were performed. It was necessary to study the binder obtained by means of a substitute for the cement. This study concentrated on strength development according to the concentration of NaOH solution, the curing temperature, and the curing time. The highest compressive strength of compression bodies appeared as $353kgf/cm^2$ cured at $80^{\circ}C$ for 28 days. This result indicates that a higher curing temperature is needed to get a higher strength body. Also, geopolymerization was examined by SEM and XRD analysis after the curing of compression bodies. According to SEM and XRD, the main reaction product in the alkali activated briquette ash is aluminosilicate crystal.

ASR Resistance of Ternary Cementitious Systems Containing Silica Fume-Fly Ash Using Modified ASTM C 1260 Method

  • Shon, Chang-Seon;Kim, Young-Su;Jeong, Jae-Dong
    • 콘크리트학회논문집
    • /
    • 제15권3호
    • /
    • pp.497-503
    • /
    • 2003
  • Supplementary cementitious materials (SCM) such as fly ash, ground granulated blast furnace slag and silica fume are now being extensively used in concrete to control expansion due to alkali-silica reactivity (ASR). However, the replacement level of a single SCM needed to deleterious ASR expansion and cracking may create other problem and concerns. For example, incorporating silica fume at levels greater than 10% by mass of cement may lead to dispersion and workability concerns, while fly ash can lead to poor strength development at early age, The combination of silica fume and fly ash in ternary cementitious system may alleviate this and other concerns, and result in a number of synergistic effects. The aim of the study was to enable evaluation of more realistic suitability of a silica fume-fly ash combination system for ASR resistance based on an in-house modification of ASTM C 1260 test method. The modification can be more closely identified with actual field conditions. In this study three different strengths of NaOH test solution(1N, 0.5N, and 0.25N) were used to measure the expansion characteristics of mortar bar made with a reactive aggregate. The other variable included longer testing period of 28 days instead of a conventional 14 days.

Adsorption of Dyes from Aqueous Solution by Cow Dung Ash

  • Rattan, V.K.;Purai, Abhiti;Singh, Harminder;Manoochehri, Mahboobeh
    • Carbon letters
    • /
    • 제9권1호
    • /
    • pp.1-7
    • /
    • 2008
  • The ability of cow dung ash without any pretreatment to remove color from textile dyes N Blue RGB, Green B and EOSIN YWS from aqueous solution has been investigated in this work. Cow dung ash, an ecofriendly and low cost adsorbent was prepared by burning cow dung cakes in the muffle furnace at $500^{\circ}C$. The adsorption was achieved under different pH and adsorbate concentration. The data was fitted to simple polynomial and the isotherms similar to Langmuir and Freundlich isotherms.

Strength & Microstructure of Class-C fly Ash Activated in Waste Glass Based Alkaline Solution

  • Sasui, Sasui;Kim, Gyu Yong;Pyeon, Su Jeong;Suh, Dong Kyun;Lee, Yae Chan;Nam, Jeong Soo
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2021년도 봄 학술논문 발표대회
    • /
    • pp.136-137
    • /
    • 2021
  • The soda lime waste glass powder was dissolved in NaOH-4M solution to synthesize an alkaline activator, which was used to activate Class-C fly ash (FA). Compressive and flexural strength tests were conducted to determine the mechanical properties. Archimedes' principle was applied to measure the porosity of samples, (SEM-EDX) and XRD was used to study the microstructure and phase changes of samples. Through Inductive Coupled Plazma technique, the solution was found to increase the concentration of Si as the amount of dissolved glass powder was increased. Owing to the increased concentration of Si in an alkaline solution, the reactivity of FA was accelerated resulting in an increased strength and reduced porosity. Additionally, the dissolution of FA was improved as well as the formation of amorphous phases in the matrix was also enhances with the concentration of increased Si in an alkaline solution.

  • PDF

Mechanical and durability properties of fly ash and slag based geopolymer concrete

  • Kurtoglu, Ahmet Emin;Alzeebaree, Radhwan;Aljumaili, Omar;Nis, Anil;Gulsan, Mehmet Eren;Humur, Ghassan;Cevik, Abdulkadir
    • Advances in concrete construction
    • /
    • 제6권4호
    • /
    • pp.345-362
    • /
    • 2018
  • In this paper, mechanical and short-term durability properties of fly ash and slag based geopolymer concretes (FAGPC-SGPC) were investigated. The alkaline solution was prepared with a mixture of sodium silicate solution ($Na_2SiO_3$) and sodium hydroxide solution (NaOH) for geopolymer concretes. Ordinary Portland Cement (OPC) concrete was also produced for comparison. Main objective of the study was to examine the usability of geopolymer concretes instead of the ordinary Portland cement concrete for structural use. In addition to this, this study was aimed to make a contribution to standardization process of the geopolymer concretes in the construction industry. For this purpose; SGPC, FAGPC and OPC specimens were exposed to sulfuric acid ($H_2SO_4$), magnesium sulfate ($MgSO_4$) and sea water (NaCl) solutions with concentrations of 5%, 5% and 3.5%, respectively. Visual inspection and weight change of the specimens were evaluated in terms of durability aspects. For the mechanical aspects; compression, splitting tensile and flexural strength tests were conducted before and after the chemical attacks to investigate the residual mechanical strengths of geopolymer concretes under chemical attacks. Results indicated that SGPC (100% slag) is stronger and durable than the FAGPC due to more stable and strong cross-linked alumina-silicate polymer structure. In addition, FAGPC specimens (100% fly ash) showed better durability resistance than the OPC specimens. However, FAGPC specimens (100% fly ash) demonstrated lower mechanical performance as compared to OPC specimens due to low reactivity of fly ash particles, low amount of calcium and more porous structure. Among the chemical environments, sulfuric acid ($H_2SO_4$) was most dangerous environment for all concrete types.

황산화세균 Thiobacillus thiooxidans에 의한 fly ash의 중금속 제거 특성:고형물 농도의 영향 (Characterization of Heavy Metals Bioleaching from Fly Ash by a Sulfur-Oxidizing Bacterium Thiobacillus thiooxidans: Effect of Solid Concentrations)

  • 조경숙;문희선;이인숙
    • 환경생물
    • /
    • 제17권2호
    • /
    • pp.183-190
    • /
    • 1999
  • The bioleaching of heavy metals from fly ash was performed by Thiobacillus thiooxidans MET isolated from the enrichment culture of an anaerobically digested sludge. The effect of solid concentrations on the efficiency of metal leaching was studied in shaken flasks. In the range of solid concentrations 20 g.L­$^1$to 100 g.L­$^1$T. thiooxidans MET oxidized S$^{0}$ to sulfate without any lag period. The final pH of slurry solution was decreased to below pH 1, and the final oxide-redox potential (ORP) was increased to over 420 mV in the solid concentrations below 100 g.L­$^1$. However, the initial lag period of 4 to 8 days was required to obtain the pH reduction and ORP increase of the slurry solutions in the range of solid concentrations 150 g.L­$^1$to 300 g.L­$^1$. The sulfur oxidation rate of T. thiooxidans MET in 20~100 g.L­$^1$solid concentrations was 0.70~0.75 g-S.L­$^1$ㆍ d­$^1$, but its sulfur oxidation activity was remarkably inhibited with increasing solid concentration over 150 g.L­$^1$. Increasing fly ash solids concentration in the range of solids concentration 20 g.L­$^1$ to 200 g.L­$^1$decreased the removal efficiency of Zn, Cu, Mn, Cr and Pb. The solubilization of heavy metals from fly ash was strongly correlated with the pH value of slurry solution. When the pH of slurry solution was reduced to 3, the solubilization process of Zn, Cu and Mn started, and their solubilization efficiency of Zn, Cu and Mn was progressively increased below pH 2. However, the solubilization process of Cr and Pb started at pH 2.5 and 2.0, respectively.

  • PDF

Release of Ammonia Odor from AAFA (Ammonia Adsorbed Fly Ash) by Installation of NOx Reduction System

  • Kim, Jae-kwan;Park, Seok-un;Lee, Hyun-dong;Chi, Jun-wha
    • KEPCO Journal on Electric Power and Energy
    • /
    • 제2권3호
    • /
    • pp.437-445
    • /
    • 2016
  • This paper discussed the effect of ammonia concentration adsorbed on fly ash for the ammonia emission as AAFA (Ammonia Adsorbed Fly Ash) produced from coal fired plants due to operation of NOx reduction technologies was landfilled with distilled or sea water at closed and open systems, respectively. Ammonia bisulfate and sulfates adsorbed on fly ash is highly water soluble. The pH of ammonium bisulfate and sulfate solution had significant effect on ammonia odor emission. The effect of temperature on ammonia odor emission from mixture was less than pH, the rate of ammonia emission increased with increased temperature when the pH conditions were kept at constant. Since AAFA increases the pH of solution substantially, $NH_3$ in the ash can release the ammonia order unless it is present at low concentration. $NH_4{^+}$ ion is unstable in fly ash and water mixtures of high pH at open system, which is changed to nitrite or nitrate and then released as ammonia gas. The proper conditions for < 20 ppm of ammonia concentration released from the AAFAs landfilled in ash pond were explored using an open system with sea water. It was therefore proposed that optimal operation to collect AAFA of less than 168 ppm ammonia at the electrostatic precipitator were controlled to ammonia slip with less than 5 ppm at SCR/SNCR installations, and, ammonia odor released from mixture of fly ash of 168 ppm ammonia with sea water under open system has about 20 ppm.

홍화의 홍색소 추출 용제의 종류에 따른 색상 변화 (Effect of Extraction Solvents on Color of the Dyed Fabrics with Safflower Red Colorants)

  • 손경희;신윤숙;류동일;최희;조아랑
    • 한국의류학회지
    • /
    • 제32권3호
    • /
    • pp.486-493
    • /
    • 2008
  • 전통적인 알칼리 추출액인 콩대 잿물과 탄산칼륨수용액을 사용하여 홍색소를 추출하고 면, 마, 레이온, 견, 모, 그리고 나일론 직물에 염색하였다. 염색한 직물의 표면반사율과 염착량, 표면색을 측정하여 추출용제에 따른 차이를 비교 하였으며, 염색견뢰도를 평가하여 다음과 같은 결론을 얻었다. 1. 면, 마, 레이온, 그리고 견직물의 표면반사율 곡선은 추출용제에 따라 거의 같은 형태를 보였으며 최대흡수파장은 520nm에서 나타났다. 모와 나일론의 표면반사율 곡선형태는 추출용제간에 차이를 보였으며 최대흡수파장은 400nm에서 나타났다. 그리고 최대흡수파장 이외에 모는 520nm, 나일론은 540nm 파장부근에서 흡수대를 보였다. 2. 면, 마, 레이온, 견의 염착량은 잿물로 추출한 경우에 약간 더 높았으며, 모는 추출용매에 상관없이 비슷한 염착량을 보였고, 나일론은 탄산칼륨으로 추출한 경우에 약간 더 높게 나타났다. 3. 나일론 직물의 $L^{*}$값과 레이온의 $b^{*}$값을 제외하고는 탄산칼륨으로 추출하여 염색한 직물의 $L^{*},\;a^{*},\;b^{*}$, 그리고 $C^{*}$ 값이 잿물 추출에서 보다 더 높게 나타났다. 단 $a^{*},\;b^{*},\;C^{*}$ 값은 모와 나일론을 제외하고는 추출용제간의 차이가 매우 미비하였다. 잿물과 탄산칼륨 추출액으로 염색한 직물의 색차는 면, 견, 마, 레이온, 모직물, 그리고 나일론 순으로 크게 나타났다. 4. 잿물과 탄산칼륨수용액 추출에 의한 색상계열 차이는 나타나지 않았으며, 면, 레이온, 나일론은 RP계열, 마와 견은 R계열, 그리고 모는 YR계열로 나타났다. 나일론을 제외하고는 탄산칼륨수용액으로 추출한 경우에 더 밝고 선명한 색상으로 염색되었다. 5. 추출용제에 따른 세탁견뢰도에는 차이가 없었으며, 나일론, 레이온, 그리고 면과 마의 순으로 우수하였고 이염도 거의 나타나지 않았다. 견과 모의 드라이클리닝 견뢰도도 매우 우수하였다. 일광견뢰도도 추출용제에 따른 차이를 보이지 않았으나, 매우 낮게 나타났다. 6. 색상과 견뢰도 등에 큰 차이가 없으므로 전통적인 잿물 대신 탄산칼륨수용액을 추출용제로 사용하는 것이 색의 재현성이나 공정상의 측면에서 색의 표준화연구에 더 효율적인 방법이라 사료된다.

바텀애시를 사용한 모르터의 특성에 대한 실험적 연구 (An Experimental Study on Properties of Mortar using Bottom Ash)

  • 송민섭;김영덕;나철성;최경렬;김재환;김무한
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2003년도 학술.기술논문발표회
    • /
    • pp.61-65
    • /
    • 2003
  • Bottom ash among the coal ash is not used because of its poor properties. But encouraging the use of bottom ash as a construction material is a sensible method of utilization as it avoids the problems and costs associated with disposal and provides an alternative aggregate source. This study was aimed at using bottom ash as an alternative fine aggregate source to provide a solution to disposal and insufficient fine aggregate for the production of concrete. So properties of domestic bottom ash were estimated due to the difference of each domestic bottom ash. And compressive strength and durability were estimated as basic data to use bottom ash in building industries. As a result of the experiment, the very porous surface and angular shape of the bottom ash particles necessitate a higher apparent water-cement ratio. And due to the higher water requirement, the compressive strength and durability of mortar is lower than those of the control samples. But when 25 percent of the total dry weight of the natural fine aggregate was replaced by bottom ash, the engineering characteristics were similar.

  • PDF

소목 천연 염색에 관한 연구 II -잿물의 매염효과에 대하여- (A Study on Natural Dyeing using Caesalpinia sappan -Mordanting Effect of Rice Straw Ash Solution-)

  • 권민수;최인려;김종준;전동원
    • 복식문화연구
    • /
    • 제12권6호
    • /
    • pp.908-917
    • /
    • 2004
  • In the previous article, the effect of aluminum compounds on the mordanting of the Caesalpinia sappan L. dyeing was studied. According to the type of the compound, the effect on the dyeing was found to be different even if $Al^{3+}$ ion was present in the molecular structure of the compound. It was postulated that there would be complex effects other than the effects based on the purified Al compounds only, since there are some amount of compounds hard to neglect. In order to reproduce the traditional dyeing practice, rice straw ash solutions were prepared as mordanting agents. The pH values of the solution baths were 4, 5, 6, 9, and 11 in order to investigate the pH effect on the color development by adding appropriate amount of Schizandra chinensis extract solution. The inherent dyeing properties were evaluated by the analysis of color difference, air permeability, the characteristics developed by pre-mordanting, post-mordanting, or simultaneous mordanting methods.

  • PDF