• Title, Summary, Keyword: 비산재

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Characterization of Granular Fertilizer Produced by Fly Ash from a Sewage Sludge Incinerator (하수슬러지 소각 비산재를 이용한 입상비료 조립 및 특성분석)

  • Kim, Seong-beom;Lee, Wontae
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.10
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    • pp.574-579
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    • 2016
  • This study assessed feasibility of making granular fertilizer with fly ash from a sewage sludge incinerator in Korea. Composition, characteristics, strength, and heavy metal contents of the granular fertilizers were investigated. Due to its high contents of phosphorus, fly ash from a sewage sludge incinerator could be used to make fertilizers. Granulation rates (2-4 mm granules) over 80% could be achieved as the fly ash contents were 15% or less of the fertilizer. Leaching tests of the fertilizers, based upon the Korean Standard Methods for Solid Wastes, showed the concentrations of heavy metals less than the risk limits. However, contents analysis of the fertilizers, based upon the Korean Standard Methods for Soils, experienced higher levels of heavy metals than the risk limits as the fly ash content exceeded 7% of the fertilizer. Thus, the fly ash needs to be added less than 7% of the fertilizer if there is no pretreatment to remove heavy metals.

Reaction Characteristics of Elemental and Oxidized Mercury with Fly Ash Components (비산재 성분과 원소 및 산화수은의 반응특성)

  • Lee, Sang-Sup;Kim, Kwang-Yul;Oh, Kwang-Joong;Jeon, Jun-Min;Kang, Dong-Chang
    • Clean Technology
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    • v.19 no.4
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    • pp.453-458
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    • 2013
  • Fly ash has capacity to oxidize or adsorb mercury in a flue gas. Mercury oxidation and adsorption efficiencies of fly ash vary depending on the properties of fly ash. This study was designed to understand reaction characteristics of mercury with fly ash components. The fly ash components were tested to determine their oxidation and adsorption capabilities for elemental mercury and oxidized mercury. A sample was synthesized with fly ash components and tested. The test results were compared with those of the fly ash sample obtained from a coal-fired power plant. $Fe_2O_3$, CuO and carbon black showed higher oxidation or adsorption efficiency for elemental mercury while CaO, MgO, CuO and carbon black showed higher adsorption efficiency for mercury chloride. In addition, the synthesized sample showed comparable mercury oxidation and adsorption efficiencies to the fly ash sample.

Study on Reduction Unburned Carbon Contents in Low Quality Fly Ash from Vietnam (베트남 저품위 비산재의 미연탄소 함량 저감 연구)

  • Kim, Keeseok;Lee, Jaewon;Lee, Dongwon;Min, Kyongnam
    • Resources Recycling
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    • v.29 no.2
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    • pp.37-47
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    • 2020
  • According to Vietnam government establishes additional thermal power plant, processing the coal ash from power plant is urgent issue. This study targeted reducing unburned carbon contents in low quality fly ash to below 6% that according to international standards. As a result, the unburned carbon contents of low quality fly ash was high and irregular as 5.3~23.6%, and it was possible to reduce unburned cabon contents to under 6%, in case of unburned carbon contents below 9.8% ashes using air classification, in case of unburned carbon contents below 23.6% ashes using combined process composed of air classification and electrostatic separation.

CO2 Capture Performance of Dry Sorbents Manufactured by Coal Fly Ash (석탄 화력발전소의 비산재를 이용한 건식 CO2 흡수제 제조 및 특성 연구)

  • Lee, Jae Hee;Wee, Jung-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.8
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    • pp.547-553
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    • 2013
  • This paper investigates the effect of coal-fired fly ash on dry $CO_2$ sorbents as the supports and additives. For this purpose, various kinds of dry sorbent were manufactured by mixing fly-ash, the primary $CO_2$ absorption components (NaOH and CaO) and water with their different combination. Thereafter, their $CO_2$ absorption performance and the property were analyzed. As a result, variation of absorption efficiency and temperature as well as $CO_2$ desorption of the sorbents are confirmed, which may be primarily ascribed to fly-ash addition to the sorbents. Particularly, fly-ash effect is strongly measured in the sorbent manufactured by mixing all four components (named WNCF sorbents). Absorption efficiency of WNCF sorbents at $550^{\circ}C$ is 35.6% higher than that of flyash free sorbent and desorption is solely observed in WNCF sorbents. Fly-ash in WNCF sorbents leads to increase the dispersity of $CO_2$ absorption components and decrease their particle size in the sorbents. In addition, fly-ash is used as the supports and pozzolanic reaction is hindered by NaOH in WNCF sorbent. Furthermore, $CO_2$ desorption from the sorbents may be due to fly-ash. The interaction between fly-ash and $CO_2$ absorption components substantially attenuate the strength between captured $CO_2$ in CaO and NaOH.

Synthesis of Zeolite Using Discharged Fly Ash in an Industrial Complex in Ulsan (울산지역 공단에서 발생되는 비산재를 이용한 제올라이트 합성)

  • Lee, Chang-Han;Park, Jong-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.5
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    • pp.301-306
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    • 2011
  • In this study, zeolite was synthesized by hydrothermal, fusion, and fusion/hydrothermal methods with fly ash, coal fly ash, and a waste catalyst discharged from thermal power plants and incinerator in Ulsan area. Coal fly ashes (CFAs) and a waste catalyst containing amounts of $SiO_2$ and $Al_2O_3$ ranging from 60.29 to 89.62 wt%. CFAs were mainly composed of quartz and mullite which were assayed by a XRD pattern. Zeolite could be synthesized by CFAs and the waste catalyst when all methods were used. Na-A zeolite (Z-C1, Z-C2, and Z-W5) are mainly synthesized by the fusion method from CFAs and the waste catalyst. Z-C1 and Z-C2 formed by-products, calcite peaks, which is caused by the content of CaO in CFAs and the addition of $Na_2CO_3$ for a synthetic process.

Characteristics of sintered fly ash-clay body prepared by slip processing and its applicability for foundation soils (슬립 공정으로 제조된 비산재-점토 계 소결체의 물성 및 기반재로의 적용특성)

  • Kang, Seung-Gu;Lee, Yeong-Saeng
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.18 no.6
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    • pp.271-276
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    • 2008
  • The civil engineering properties for the coal fly ash produced from a power plant mixed with sintered powders made from the fly ash-clay slip system were measured and its applicability for the foundation soils was investigated. The F-slip whose dispersion state is 'not good' and C-slip which is re-flocculated by adding a flocculant to a well-dispersed slip were fabricated and then sintered. The sintered body made from C-slip had more uniform microstructure than that of F-slip, therefore, the bulk density and compressive strength were improved. The civil engineering properties such as compression index, compressive strength, permeability coefficient of fly ash were improved by mixing $0.84{\sim}2\;mm$ powders obtained by crushing a sintered body made from C-slip. Therefore, the applicability of mixed powders composing of fly ash and sintered body made from C-slip was confirmed to foundation soils due to its improved civil engineering properties.

Kinetic Studies of CO2 Gasification by Non-isothermal Method on Fly Ash Char (비등온법에 의한 비산재 촤의 CO2 가스화 특성)

  • Kang, Suk-Hwan;Ryu, Jae-Hong;Lee, Jin-Wook;Yun, Yongseung;Kim, Gyoo Tae;Kim, Yongjeon
    • Korean Chemical Engineering Research
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    • v.51 no.4
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    • pp.493-499
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    • 2013
  • For the purpose of utilizing fly ash from gasification of low rank coal, we performed the series of experiments such as pyrolysis and char-$CO_2$ gasification on fly ash by using the thermogravimetric analyzer (TGA) at non-isothermal heating conditions (10, 20 and $30^{\circ}C/min$). Pyrolysis rate has been analyzed by Kissinger method as a first order, the reliability of the model was lower because of the low content of volatile matter contained in the fly ash. The experimental results for the fly ash char-$CO_2$ gasification were analyzed by the shrinking core model, homogeneous model and random pore model and then were compared with them for the coal char-$CO_2$ gasification. The fly ash char (LG coal) with low-carbon has been successfully simulated by the homogeneous model as an activation energy of 200.8 kJ/mol. In particular, the fly ash char of KPU coal with high-carbon has been successfully described by the random pore model with the activation energy of 198.3 kJ/mol and was similar to the behavior for the $CO_2$ gasification of the coal char. As a result, the activation energy for the $CO_2$ gasification of two fly ash chars don't show a large difference, but we can confirm that the models for their $CO_2$ gasification depend on the amount of fixed carbon.

Manufacturing of Artificial Lightweight Aggregates using a Coal Fly Ash Discharged from Fluidized Bed Combustor (유동층(流動層) 연소기(撚燒器)로 부터 발생(發生)된 석탄(石炭) 비산(飛散)재를 이용(利用)한 인공경량골재(人工輕量骨材) 제조(製造))

  • Kang, Min-A;Kang, Seung-Gu
    • Resources Recycling
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    • v.20 no.1
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    • pp.54-60
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    • 2011
  • The spherical artificial aggregates (AAs) with a diameter of 8 mm, which contains fly ashes discharged from the fluidized bed combustion in a thermal power plant and clay were manufactured by direct sintering method at $1050{\sim}1250^{\circ}C$ for 10 minutes. The effect of fly ash contents on the bloating phenomenon in the AAs was analyzed. The AAs containing fly ash of the amount under 50 wt% showed the black-coring and bloating phenomena. The AAs containing fly ash of the amount over 5Owt%, however, the specific gravity was increased and the color of specimens fully changed to black. These color change phenomena were caused from the formation of FeO by the reduction reaction of almost $Fe_2O_3$ component by the excessive reducing atmosphere formed simultaneously with the rapid emission of the gases generated from the high contents of unburned carbon of with increasing the added fly ash amount. Specific gravity was decreased as fly ash contents increased in the case of sintering at the same temperature condition. Water absorption of all specimens except of the specimens containing 10 wt% fly ashes decreased with increasing sintering temperature. These were because a liquid phase was formed as the increasing the sintering temperature. In the case of the specimens manufactured in this study containing fly ashes discharged from the fluidized bed combustor in a the thermal power plant and 10~90 wt% of clay, the specific gravity was 0.9~1.8 and the water absorptivity was 8~60%, therefore it is considered that those results can be applied to the light or heavy aggregates.

Characterization of Fly Ash Produced from a Sewage Sludge Incineration Facility in Korea (국내 하수슬러지 소각시설에서 발생되는 비산재의 특성 분석)

  • Kim, Seong-beom;Lee, Wontae
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.2
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    • pp.96-99
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    • 2016
  • This study characterized fly ash produced from a sewage sludge incineration facility in Korea to determine if the byproducts can be utilized. All the incinerated sewage sludge was from a city in Korea. To characterize fly ash and to determine if it can be utilized, pH, water contents, elemental components, particle size, surface morphology, heavy metal compositions, and others were analyzed. In average, pH was 6.2, and water contents was about 5%. T-N and $T-P_2O_5$ were 3% and 24.5%, respectively. Particle size averaged 836 nm; surface morphology did not exhibit any significant results. X-ray diffraction (XRD) analysis results revealed that major components of the fly ash were $P_2O_5$, CaO, MgO, $K_2O$. Composition of heavy metals by the Korea Standard Methods for Waste Quality did not exceed the criteria for specified wastes in Korea.

Leaching Property of Coal Fly Ash Using Water as the Solvent and Its Carbonation Performance (석탄 비산재의 물에 대한 침출 특성과 탄산화 성능에 관한 연구)

  • Shin, Jiyoon;Han, Sang-Jun;Wee, Jung-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.3
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    • pp.198-205
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    • 2014
  • The present paper investigates the leaching property of coal fly ash (FA) using distilled water as solvent and its performance of mineral carbonation. The highest leaching efficiency is obtained at 100 min after leaching begins and the overall leaching efficiencies of Ca and Na via five consecutive leachings were calculated to be 25.37% and 7.40%, respectively. In addition, because $Ca(OH)_2$ produced during the leaching reacts with $SiO_2$ which is the major component of FA, the Pozzolanic reaction may occur and thus reduces leaching efficiency. Total carbonation capacity of FA by absorbing $CO_2$ into FA leachates is 6.08 mg $CO_2/g$ FA and the contribution of alkali substances such as Ca, Na, Mg and K to this value is calculated to be 5.19 mg $CO_2/g$ FA. Carbonation efficiencies of Ca and Na based on leachates are 85.62% and 77.70%, respectively. On the other hand, the ratios of Ca and Na in raw FA to participate in carbonation are calculated to be 9.04% and 5.26%, respectively.