• Title, Summary, Keyword: Coal ash

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Performance of bricks and brick masonry prism made using coal fly ash and coal bottom ash

  • Verma, Surender K.;Ashish, Deepankar K.;Singh, Joginder
    • Advances in concrete construction
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    • v.4 no.4
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    • pp.231-242
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    • 2016
  • The major problem of a coal combustion-based power plant is that it creates large quantity of solid wastes. So, to achieve the gainful use of waste materials and to avoid other environmental problems, this study was undertaken. The quantity of coal ash by-products, particularly coal fly ash and coal bottom ash has been increasing from the coal power plants around the world. The other objective of this study was to explore the possibility of utilization of coal ash in the production of ash bricks. In 15 different mixes, Mix Designation M-1 to M-15, the varying percentages of lime and gypsum were used and sand was replaced with coal bottom ash. Further, it has been noticed that the water absorption and compressive strength of mix M-15 is 13.36% and 7.85 MPa which is better than the conventional bricks. The test results of this investigation show that the prism strength of coal ash masonry prisms was more than that of the conventional bricks.

A Study on the Durabilities of High Volume Coal Ash Concrete by the Kinds of Coal Ash (석탄회 종류에 따른 석탄회를 대량 사용한 콘크리트의 내구특성에 관한 연구)

  • Choi, Se-Jin;Kim, Moo-Han
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.3
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    • pp.73-78
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    • 2009
  • Coal ash is a by-product of the combustion of pulverized coal, and much of this is dumped in landfills. The disposal of coal ash is one of the major issues for environmental problems. In this paper, the effects of the kinds and replacement ratio of coal ash on the durabilities of concrete mixtures are investigated. Fine aggregate was replaced with coal ash(fly ash and bottom ash) in five different ratios, of 0%, 10%, 20%, 35%, and 50% by volume. Test results indicated that the compressive strength increased with the increase in fly ash percentage. The loss of compressive strength of bottom ash concrete mixes after immersion in sulphuric acid solution was less than in the control mix(BA0). In addition, the carbonation depth of fly ash concrete mixes was lower than the control mix(FA0).

A Study on the Ceramic Body and Art Glaze by Using Coal Ash (도예용 소지 및 유에 석탄재 적용 연구)

  • Ri, Se-W;Park, Sung;Chung, Yun-Joong
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.548-553
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    • 2009
  • This study is on the application of ceramic body and art glaze by using coal ash according to each wt%. Body color was turned red and dark as increasing coal ash contents in the body and art glaze because of the effect of noncombustible carbon in $Fe_2O_3$ and coal ash. Not only pore and black core were generated but also absorptance and shrinkage were increased as increasing coal ash contents. The glaze of coal ash 20 wt% showed blue absorption band, turned red band as increasing coal ash contents, $Al_2O_3\;to\;SiO_2$ ratio got lower and became mat because glaze is estranged from $Al_2O_3\;to\;SiO_2$ mol ratio 1:10 of transparent glaze as increasing coal ash contents. Glaze showed unstable dissolving condition in the more coal ash contents.

Strength and durability characteristics of bricks made using coal bottom and coal fly ash

  • Ashish, Deepankar Kumar;Verma, Surender Kumar;Singh, Joginder;Sharma, Namesh
    • Advances in concrete construction
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    • v.6 no.4
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    • pp.407-422
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    • 2018
  • The study evaluates properties of brick having coal ash and explores the possibility of utilization of coal bottom ash and coal fly ash as an alternative raw material in the production of coal ash bricks. Lower cement content was used in the investigations to attain appropriate strength and prohibit high carbon content that is cause of environmental pollution. The samples use up to 7% of cement whereas sand was replaced with bottom ash. Bricks were tested for compressive strength, modulus of rupture, ultrasonic pulse velocity (UPV), water absorption and durability. The results showed mix proportions of bottom ash, fly ash and cement as 1:1:0.15 i.e., M-15 achieved optimum values. The coal ash bricks were well bonded with mortar and could be feasible alternative to conventional bricks thus can contribute towards sustainable development.

Overview of coal-fired power plant ash situation and cement industry in Vietnam

  • Hong, Ha Thi Vu;Ahn, Ji Whan
    • Journal of Energy Engineering
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    • v.27 no.3
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    • pp.57-62
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    • 2018
  • The development of coal-fired power plants to ensure energy security and electricity consumption is a matter for the Vietnam economy. However, the huge amount of ash discharged is a major environmental challenge. It is estimated that by the end of 2017, the amount of ash in the country is about 40 million tons and annually emitted over 16.4 million tons. While the quantity of coal-fired power plant is rising, the ash content will increase year by year if the ash doesn't treat well. The ash will be increased from 61 million tons in 2018 to 109 million tons in 2020, 248 million tons in 2025 and 422 million tons in 2030. The difficulties of coal-fired power plants are the problem of ash handling, some plants are at risk of closure because there are not enough dump capacity to storage. Therefore, Vietnam is in need of urgent measures to treat a large amount of waste from coal-fired power plants. The specific objectives of this study were as follows: (1) provide an overview of coal ash situation produced by coal-fired power plants in Vietnam; (2) study about regulations related to coal ash treatment; (3) comprehend the literature review of the cement sector status.

A Study on the Recycling of Coal Ash as Fill Materials (석탄회 자원의 채움재로서의 활용에 관한 연구)

  • 천병식;고용일;송경율;이준기
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.513-520
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    • 1999
  • 20 million tons of coal ash has been produced in Korea annually. This causes the environmental problems and the cost of land for ash pond. However the amount of coal ash for recycling is small because of the low level of recycling technology and the ignorance. As the coal ash has the significant engineering properties, it can be utilized as soft ground stabilizer, backfill materials and so forth. The purpose of this paper is to summarize some of the recycling methods of coal ash. One is structural backfill materials, the other is flowable fill. Optimal mixture ratio(fly ash : bottom ash) is determined for structural backfill materials and the model test is performed. The model test accompanied with physical tests were executed for identifying that the flowable fly ash can be used as fill materials such as trench back filling.

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An Experimental Study on the Properties of High Volume Reclaimed Coal Ash Concrete (매립석탄회 고배합 콘크리트의 특성)

  • 한상묵;이종림;하재담;김태홍
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.7-10
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    • 2003
  • The amount of coal ash has been increasing and development of effective use is urgently needed. Various by-products and waste are expected to be used as resources from the point of reduction in environmental load. This is an experimental study to compare the properties of high volume coal ash concrete using the reclaimed coal ash. For this purpose, the mix proportion of concrete according to the content ratio of below 5mm reclaimed coal ash (0.65, 0.70, 0.75 and 0.80). And then air content, slump, compressive strength test were performed. According to test results, it was found that the compressive strength of reclaimed coal ash concrete was similar to the content ratio of below 5mm reclaimed coal ash. And the slump of reclaimed coal ash concrete decreased as the content ratio of below 5mm.

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The Study on the Engineering Characteristics by Self-Hardening of Coal Ash (석탄회의 자경성에 따른 공학적 특성연구)

  • Sang, Jung-Hyuk;Shin, Woong-Gi;Kim, Ji-Won;Chun, Byung-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.81-87
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    • 2010
  • As enormous construction projects of land development are carried out around Korea, useful construction materials are needed to perform the construction projects. However, there are no more enough of fill and reclamation materials in our country. That is why the coal ash is expected to be utilized as an alternative material. Since the coal ash has the characteristics of a pozzolan and a selfhardening material, it is adjudged that coal ash has a great possibility to be used as a fill and reclamation material. In this study, grain size analysis, Atterberg limit test, and specific gravity test were performed to examine the physical characteristics of the coal ash about a self-hardening material before utilizing the coal ash in the construction. Compaction test, unconfined compression test were conducted to investigate the engineering characteristics according to mixture ratios of fly ash and bottom ash. As a result of the tests, it was confirmed that the mixing ratio 1:1 of fly ash and bottom ash is the most effective to use as a fill and reclamation material. If the mixture of coal ash is used as a backfill material with light weight around structure, it is expected to play a significant role in reducing earth pressure on the back of the structure. As described above, the coal ash should be considered as an alternative material of fill and reclamation materials since the result of the tests indicates that the coal ash is suitable to a useful material on the construction design.

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An Experimental Study on the Properties of Concrete using High Volume of Coal Ash

  • Kim, Moo Han;Choi, Se Jin
    • Architectural research
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    • v.4 no.1
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    • pp.39-44
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    • 2002
  • Recently, the coal-ash production has been increased by increase of consumption of electric power. So it is important to secure a reclaimed land from pollution and develop practical application of coal ash. This is an experimental study to compare and analyze the properties of concrete using high volume of coal ash (including fly ash and bottom ash) as a part of fine aggregate. For this purpose, the mix proportions of concrete according to replacement ratio of coal ash (10, 20, 35, 50%) were selected. And then air content, slump, setting time, bleeding content, chloride content, compressive strength and carbonation test were performed. According to test results, it was found that the bleeding content of concrete using the coal ash decreased according to increase of replacement ratio. And the chloride content of concrete using the bottom ash as a part of fine aggregate increased as the replacement ratio of bottom ash increased, but it is satisfied with the total chloride content of concrete recommended by KCI - $0.3kg/m^3$ below. Also, the compressive strength of concrete using the bottom ash was similar to that of plain concrete(BA 0) after 28days of curing and the carbonation depth of concrete increased as the replacement ratio increased. However, the carbonation depth of concrete using the fly ash decreased as the replacement ratio of fly ash increased.

Technology for the Preparation of Ash-free Coal from Low Rank Coal(LRC) (저등급 석탄으로부터 초청정석탄 제조 기술)

  • Lee, Sihyun;Kim, Sangdo
    • Korean Chemical Engineering Research
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    • v.46 no.3
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    • pp.443-450
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    • 2008
  • Efficient use of low rank coals (LRC) have been investigated as a method to cope with recent high oil price. Among the coals used in industry, lignite and sub-bituminous coals are belong to the LRC, and have abundant deposit and are distributed worldwide, but high moisture contents and self ignition properties inhibits their utilization. In this paper, chemical coal cleaning to produce ash-free coal from LRC has been investigated. Two technologies, that is, UCC(Ultra Clean Coal) process removing ash from coal and Hyper Coal process extracting combustibles from coal were compared with. UCC process has merits of simple and reliable when it compared with Hyper Coal process, but the remaining ash contents werehigher than Hyper Coal. Hyper Coal has ash contents under the 200ppm when raw coal is treated with appropriate solvent and ion exchange materials to remove alkali materials in extracted solution. The ash-free coal which is similar grade with oil can be used as alternate oil in the industry, and also used as a high grade fuel for IGCC, IGFC and other advanced combustion technology.