• Title, Summary, Keyword: fly ash

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Effects of Application of Fly Ash on Tobacco Growth and on Accumulation of Heavy Metal in Soil (석탄회 시용이 연초 생육과 토양중 중금속 함량에 미치는 영향)

  • Hong, Soon-Dal;Seok, Yong-Seon;Song, Beom-Heon
    • Journal of the Korean Society of Tobacco Science
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    • v.20 no.1
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    • pp.5-12
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    • 1998
  • Pot experiment was conducted to investigate the effects of fly ash on growth responses and on accumulation of the heavy metals in soil. Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 0.4, 0.8, and 1.2 kg/pot(20L). Tobacco growth was better by application of fly ash than that by the control. However, the early stage of growth by application of bituminous coal, 1.2 kg/pot, was decreased due to the boron toxicity occurred by fly ash. Generally, tobacco yield was significantly increased with applying fly ash, showing the highest yield at 1.2 kg/pot for anthracite and at 0.8 kg/pot for bituminous coal. The content of total nitrogen in leaves was higher with fly ash than that of the control, while the content of calcium in leaves was low, Contents of heavy metal and the other minerals were not significantly different between the control and the treatment of fly ash. Soil pH after experiment was linearly increased with application level of fly ash, indicating that the application of bituminous coal was more effective than that of anthracite. Contents of available phosphate, exchangeable $Ca^{2+}$+ and $Mg^{2+}$ in soil were increased by application of fly ash, especially with bituminous coal. Contents of Cu, Cr, and Ni were increased with application level of bituminous coati even if the contents were still lower than critical levels for farming land. The other heavy metals were similar between the control and the application of fly ash.

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Basic Properties of Latex-Modified Concrete Using Fly-ash (플라이애쉬를 이용한 라텍스개질 콘크리즈의 기초물성 연구)

  • Hong, Chang-Woo;Jeong, won-Kyong;Kim, Kyong-jin;Yun, Kyong-ku
    • Journal of The Korean Society of Civil Engineers
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    • v.26 no.1A
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    • pp.205-211
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    • 2006
  • The purpose of this study was to evaluate the effects of fly-ash on strength development and durability of latex-modified concrete (LMC) and ordinary portland cement concrete (OPC). Main experimental variables were latex contents (0%, 10%, 15%) and fly-ash content (0, 10%, 20%, 30%). Air content and slump tests were performed to check the basic properties of fresh concretes, and compressive strength, flexural strength, rapid chloride ion permeability and chemical resistance were measured to analyze the basic properties of hardened concretes. The test results showed that air contents of LMC with fly ash decreased as fly-ash contents increased from 0% to 30%. Compressive and flexural strength developments of LMC with fly ash were quite similar to those of LMC without fly ash. However, the long-term flexural strength development of LMC with fly ash after 90 days were bigger than that of LMC without fly ash. Chloride ion permeability and chemical resistance decreased rapidly as the content of fly ash increased. Thus, fly ash could be used at LMC in order to reduce water permeability.

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Influence of Fly Ash Addition on Properties of Ceramic Wall Tiles (플라이애시 첨가에 따른 세라믹 벽타일 소지의 물성변화)

  • Kim, Jin-Ho;Cho, Woo-Seok;Hwang, Kwang-Taek;Han, Kyu-Sung
    • Korean Journal of Materials Research
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    • v.27 no.2
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    • pp.76-81
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    • 2017
  • Recently, there have been many efforts to establish suitable processes for recycling fly ash, which is produced in thermal power plants and which poses serious environmental problems. Use of fly ash as a major ingredient of ceramic tiles can increase fly ash utilization, as well as reduce the cost of raw materials in ceramic tile production. In this study, the effects of fly ash addition on ceramic tile properties such as bending strength, water absorption and porosity were investigated. A manufacturing process of ceramic tile was developed for utilization of fly ash with high carbon content. In this approach, it is important to hold the ceramic tiles at a temperature that is sufficient for carbon oxidation, before the pores supplying oxygen to the inside of the ceramic tile are sealed. Ceramic wall tiles were manufactured with 0-40wt% of fly ash addition. The water absorption and porosity of the fired body were slightly changed with increasing fly ash content up to 30wt% and decreased with greater amounts of fly ash addition. The bending strength of ceramic tile including 10wt% fly ash increased, reaching a level comparable to that of ceramic tile without fly ash.

Fabrication of Cement-fly Ash Mortar by Using Mechanochemical Processing(MP) (Mechanochemical Processing(MP)에 의한 Cement-fly Ash 계 Mortar의 제조)

  • Lee, Hyung-Jik;Koo, Ja-Hun;Yoo, In-Sang;Song, Doo-Gyoo;Joung, Hae-Kyoung;Kwon, Hyouk-Byoung;Yoon, Sang-Ok;Lee, Hyung-Bock;Lee, Hong-Lim
    • Journal of the Korean Ceramic Society
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    • v.39 no.2
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    • pp.126-134
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    • 2002
  • Fabrication of mortar containing fly ash for high strength structural material was investigated by using a Mechanochemically Processed Cement (MPC) and/or Fly Ash (MPFA), which was compared to the specimen (at the same fabrication condition of fly ash adding contents (10, 20 and 30 wt%) and curing time (7 and 28 days)) fabricated by using Ball-mill Processed Cement (BPC) and As Received Fly Ash (ARFA) in terms with compressive strength and microstructures. Mortar specimen fabricated by using MPC and ARFA showed 5-11% higher compressive strength than that in the case of using BPC and ARFA, and mortar specimen by using BPC and MPFA represented 10-20% higher compressive strength than that for the case of using BPC and ARFA. Furthermore, mortar specimen fabricated by simultaneously using MPC and MPFA exhibited about 24% higher value of compressive strength than that for the case of using BPC and ARFA, which was considered to be synergic efficiency in increasing compressive strength. Increased compressive strength as above mentioned is considered to be caused by mutually increased affinity between cement and fly ash induced during mechanochemical Processing(MP).

A Study on the Characterization of Anthracite Fly Ash for the Fabrication of Calcinated Brick (소성블릭 제조를 위한 무연탄 석탄회의 특성 연구)

  • Yu Yeon-Tae;Kim Byoung-Gyu;Choi Young-Yoon;Nam Chul-Woo;Lee Yeng-Seok;Kim Cheon-Sun
    • Resources Recycling
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    • v.13 no.2
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    • pp.16-23
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    • 2004
  • To increase the recycling rate of anthracite fly ash, the properties of anthracite fly ash were compared to that of bituminous fly ash. Especially, the high temperature properties of the fly ash are investigated by using thermal analysis, high temperature microscope and X-ray diffraction analysis for utilizing anthracite fly ash to prepare the calcinated bricks. The average ratio of $A1_2$$O_3$/$SiO_2$ for anthracite is 0.62 and the ratio for bituminous is 0.34. The content of $SiO_2$ in anthracite fly ash was higher than that of bituminous fly ash. The $A1_2$$O_3$ of anthracite fly ash reacted with the $A1_2$$O_3$ in the fly ash and formed new mullite crystal at over $1000^{\circ}C$, so anthracite fly ash showed high fire resistance. And, the fly ash mixtures having kaolin were prepared, and then extruded in vacuum to evaluate the extruding property of anthracite fly ash mixture. The extruding velocity was decrease with increasing the addition amount of fly ash in the mixture, and the maximum addition amount of fly ash that could be extruded was 60 wt%.

Pozzolanic reaction of classified fly ash (분급 플라이애쉬의 포졸란반응 특성)

  • Lee, Seung-Heun;Hwang, Hae-Jeong
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.753-756
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    • 2006
  • This paper discussed pozzolanic reaction properties of classified fly ashes by using of electrostatic precipitator. Blaine values of fly ashes at hoppers are respectively about 3000(ordinary), 5000(fine) and 8000cm2/g(super-fine). The pozzolanic reactivity of fly ash at early stage and at later stage are respectively related to the related to the fineness and the glass content of fly ash. But the early hydration of cement was retarded by addition of super fine fly ashes. the adiabatic temperature rise of mortar containing fly ash is increased with the fineness of fly ashes.

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Microstructure and Mechanical Properties of the Sintered Kaolin Block with Fly Ashes (Fly Ash를 이용한 고령토벽돌의 소결 특성)

  • Lee, Jin-Uk;Lee, Sung-Min;Kim, Hyung-Tae;Choi, Eui-Seok;Lee, Yong-Seok
    • Journal of the Korean Ceramic Society
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    • v.39 no.12
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    • pp.1164-1170
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    • 2002
  • The effect of fly ash addition to the kaolin block has been investigated. The addition affected the firing temperature and physical properties such as water absorption and compressive strength. The starting materials were from korea natural resources and the fly ash were from the power plant using coal as fuel, containing free carbon of 8∼9 wt%. The starting natural materials were mixed with 5 different proportions of fly ash, pressed and then sintered at 1050, 1100, 1150 and 1200${\circ}C$. With sintering temperature, water absorption decreased and compressive strength increased. When specimens were sintered at the temperature lower than 1100${\circ}C$, water absorption increased and strength decreased with fly ash content. In contrast, when sintering was done at the temperature higher than 1150${\circ}C$, water absorption increased with fly ash content similarly but strength was improved.

Crystallization of the Fly Ash from Municipal Incinerator (도시쓰레기 소각로 비산재 용융결정화 및 용출특성)

  • Lee, Hye-Mun;Kim, U-Hyeon;Lee, Jeong-Gyu
    • 연구논문집
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    • pp.5-14
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    • 2001
  • These days, interest in the leaching of hazardous heavy metals to consist of incinerator fly ash is increasing, because the heavy metals that leach from the incinerator fly ash pollute the soil and ground water. Therefore this study was undertaken to crystallize the fly ash and prevent the leaching of hazardous heavy metals from fly ash. The concentrations and the leaching concentration of hazardous heavy metals(Cd, Cr, Hg, Pb, Zn) in the law incinerator fly ash have been measured. The fly ash was melted with two kinds of flux($Na_2CO_3, CaCO_3$) and its add quantity(0, 1, 2, 3 wt%). The crystal structure of melting materials was analyzed by SEM(Scaning Electron Microscope) and X-RD(X-Ray Diffractometer). The leaching test of melting materials was undertaken. And the relation between crystallization of melting materials and flux and leaching concentration. These experiments indicate that the concentration and leaching concentration of heavy metals in incinerator fly ash was much higher than the regulatory standard for leachates in Korea and U.S.A and average concentration of heavy metals in soil. And the crystal structure was better.

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Fracture behavior of fly ash concrete containing silica fume

  • Zhang, Peng;Gao, Ji-Xiang;Dai, Xiao-Bing;Zhang, Tian-Hang;Wang, Juan
    • Structural Engineering and Mechanics
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    • v.59 no.2
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    • pp.261-275
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    • 2016
  • Effect of silica fume on fresh properties, compressive strength at 28 days and fracture behavior of fly ash concrete composite were studied in this paper. Test results indicated that the fluidity and flowability of fly ash concrete composites decreased and fly ash concrete composite are more cohesive and appear to be sticky with the addition of silica fume. Addition of silica fume was very effective in improving the compressive strength at 28 days of fly ash concrete composite, and the compressive strength of fly ash concrete composite has a trend of increase with the increase of silica fume content. Results also indicated that all the fracture parameters of effective crack length, fracture toughness, fracture energy, the critical crack opening displacement and the maximum crack opening displacement of fly ash concrete composite decreased with the addition of silica fume. When the content of silica fume increased from 3% to 12%, these fracture parameters decreased gradually with the increase of silica fume content. Furthermore, silica fume had great effect on the relational curves of the three-point bending beam specimen. As the silica fume content increased from 3% to 12%, the areas surrounded by the three relational curves and the axes were becoming smaller and smaller, which indicated that the capability of concrete composite containing fly ash to resist crack propagation was becoming weaker and weaker.

Manufacture and Properties of Coal Fly Ash-Clay Body (석탄회-점토계 소지의 제조 및 물성)

  • 송종택;윤성대;류동우;한경섭
    • Journal of the Korean Ceramic Society
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    • v.33 no.7
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    • pp.771-778
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    • 1996
  • Utilization of fly ash by-produced from coal fired power plants and classified as general waste became very important problem to solve in the environmental protection and recycling of waste materials. The possibility of large scale substitution of fly ash as a raw material for bricks and wet tiles was highly expected because the chemical compositions of fly ash were mostly Al2O3 and SiO2 and the properties of it were very similar with clay. Accordingly in order to investigate the substitutional limit these specimens were substituted from 0 to 100 wt% fly ash by 20wt% increment for clay. Fly ash-clay bodies were fired at 1200, 1250 and 130$0^{\circ}C$ and then their properties were measured, It was found that these specimens sintered at 125$0^{\circ}C$ had a good bending strength. Especially when these sintered bodies were added to 20, 40 and 60 wt% fly ash the bending strength of those were 201 , 205 and 191kg.cm2 respectively with the water absorption below 1%, This showed that fly ash could be substituted ab 60 wt% in this experiment.

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