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Yifan Zhang - One of the best experts on this subject based on the ideXlab platform.
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Sodium vapor capture by Coal Ash during sodium-rich Coal combustion
Applied Thermal Engineering, 2019Co-Authors: Jiang Fenghao, Shouyu Zhang, Huang Xiaohe, Wang Caiwei, Yifan ZhangAbstract:Abstract In this study, firstly, the release of sodium from Coal during Coal combustion was proved. Then, the capacity of sodium capture of the sodium-rich Coal Ash and the crystalline phase of the Coal Ash after sodium capture were investigated. The results showed that the content of sodium released from Coal increased with the increasing combustion temperature. The sodium content of Wucaiwan Coal Ash prepared at 900 °C (WCW-900) is saturated. The WCW-900 did not capture sodium in the flue gas, while Hami Coal Ash prepared at 900 °C (HM-900) and PS Coal Ash prepared at 900 °C (PS-900) could capture sodium effectively. With the increasing sodium capture temperature, the amount of the sodium captured by HM-900 decreased, but that of PS-900 increased and the growth rate of the amount of the sodium captured of PS-900 increased. In the sodium capture temperature range from 810 °C to 1000 °C, the amount of sodium captured by HM-900 is higher than that of PS-900, which is higher than WCW-900. The sodium capture and sodium release existed in the sodium capture process simultaneously. The sodium capture is caused by reaction between the vaporized NaCl and the minerals in the Coal Ash and the physical adsorption.
Kazuyoshi Tsuji - One of the best experts on this subject based on the ideXlab platform.
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Utilization of Coal Ash As Recycling Material Options in View Point of Geoenvironment
Advances in Environmental Geotechnics, 2010Co-Authors: Ahmad Rifa’i, Kiyoshi Omine, Noriyuki Yasufuku, Kazuyoshi TsujiAbstract:Disposed Coal Ash is result from the residual of Coal refinery processes and become environmentalimportant issues. Coal Ash consists of bottom Ash and fly Ash. The number of Coal Ash production is abundant, and can be considered as waste material if it is not effectively reused or recycled for other application. In engineering practice, utilization of fly Ash as additive materials is limited and in small quantity while the disposal of fly Ash is quite high. The major aim of this paper is to stress the characterization, classification and utilization of Coal Ash as recycling structural material in view point of geoenvironment. Also, to prove of Coal Ash contribution in geotechnical engineering, give benefit in engineering practice and also become as part of engineering material that is environmental friendly. Material characteristics involve physical, mechanical, mineral composition and chemical properties, including environmental aspect by laboratory tests are presented. Uniaxial test, CBR test, sulphate resistance test and leaching test of heavy metal contents of Coal Ash as recycling structural material were also conducted to ensure environmentally acceptable based on Indonesian standard SNI. Fly Ash is grouped in F class. Based on SNI-03-2460-1991, fly Ash sample is available as additive material in concrete. Mix design of Coal Ash paving block is conducted toward several mixes, different volumes of Coal Ash and cement to grasp optimum utilization of Coal Ash and qualify minimum standard requirement of Indonesian standard SNI 03-0691-1996. Coal Ash paving block with quality B, i.e. has compression strength 200 kg/cm2 can be mixed with fly Ash adding 30% maximum as additive, or use of 50% fly Ash as substitution with cement content is kept or using fly Ash 30% and bottom Ash 40%. Coal Ash paving block samples resist to sulphate. Effect of addition of fly Ash, bottom Ash and lime on physical and mechanical properties can improve the index properties of soft soil sub grade layer, increases bearing capacity, as well as decreases swelling potential. Coal Ash-soil mixture contains some heavy metals, but concentration values is still under boundary threshold of government act PP No. 20, 1990 about criteria of water quality in group D.
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Utilization of Coal Ash As Recycling Material Options in View Point of Geoenvironment
Advances in Environmental Geotechnics, 2010Co-Authors: Ahmad Rifa’i, Kiyoshi Omine, Noriyuki Yasufuku, Kazuyoshi TsujiAbstract:Disposed Coal Ash is result from the residual of Coal refinery processes and become environmentalimportant issues. Coal Ash consists of bottom Ash and fly Ash. The number of Coal Ash production is abundant, and can be considered as waste material if it is not effectively reused or recycled for other application. In engineering practice, utilization of fly Ash as additive materials is limited and in small quantity while the disposal of fly Ash is quite high. The major aim of this paper is to stress the characterization, classification and utilization of Coal Ash as recycling structural material in view point of geoenvironment. Also, to prove of Coal Ash contribution in geotechnical engineering, give benefit in engineering practice and also become as part of engineering material that is environmental friendly. Material characteristics involve physical, mechanical, mineral composition and chemical properties, including environmental aspect by laboratory tests are presented. Uniaxial test, CBR test, sulphate resistance test and leaching test of heavy metal contents of Coal Ash as recycling structural material were also conducted to ensure environmentally acceptable based on Indonesian standard SNI. Fly Ash is grouped in F class. Based on SNI-03-2460-1991, fly Ash sample is available as additive material in concrete. Mix design of Coal Ash paving block is conducted toward several mixes, different volumes of Coal Ash and cement to grasp optimum utilization of Coal Ash and qualify minimum standard requirement of Indonesian standard SNI 03-0691-1996. Coal Ash paving block with quality B, i.e. has compression strength 200 kg/cm2 can be mixed with fly Ash adding 30% maximum as additive, or use of 50% fly Ash as substitution with cement content is kept or using fly Ash 30% and bottom Ash 40%. Coal Ash paving block samples resist to sulphate. Effect of addition of fly Ash, bottom Ash and lime on physical and mechanical properties can improve the index properties of soft soil sub grade layer, increases bearing capacity, as well as decreases swelling potential. Coal Ash-soil mixture contains some heavy metals, but concentration values is still under boundary threshold of government act PP No. 20, 1990 about criteria of water quality in group D.
Chunhe Jiang - One of the best experts on this subject based on the ideXlab platform.
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Effect of CaO mineral change on Coal Ash melting characteristics
Journal of the Energy Institute, 2020Co-Authors: Wang Liang, Guangwei Wang, Xiaojun Ning, Jianliang Zhang, Chunhe JiangAbstract:Abstract The change of mineral composition in Ash and the effect of CaO on the melting characteristics of Coal Ash were studied by adding different contents of CaO to Coal Ash. At the same time, the Factsage thermodynamics software was used to simulate the mineral changes in the synthetic Ash to support and verify the experimental results. The results show that with the increase of CaO content, the melting characteristic temperature of Coal Ash first decreases and then rises. After adding a certain amount of CaO, the quartz with higher melting point completely disappears, and the melting point of the Coal Ash reaches a minimum value. And with the increase of CaO content, the appearance of wollastonite and single crystal calcium oxide mineral makes the melting point of Coal Ash gradually increase. It can be seen from the phase diagram calculated by Factsage that as the CaO content increases, the corresponding position of the Coal Ash gradually moves from the hematite region to the calcareous region. And the phenomenon of low temperature eutectic occurs when the CaO content is 35%, which is consistent with the trend of temperature change of the melting characteristics. These phenomena all indicate that the change in the melting point of Coal Ash is nonlinear as the content of CaO minerals increases.
Shuntarou Koyama - One of the best experts on this subject based on the ideXlab platform.
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measurement and simulation of flow properties of Coal Ash slag in Coal gasification
Aiche Journal, 2011Co-Authors: Wenjia Song, Yimin Sun, Zibin Zhu, Shuntarou KoyamaAbstract:The viscosities of 45 Coal Ash slag samples at high temperature have been measured under different temperatures and shear rates. The computer thermodynamic software package FactSage has been used to predict liquidus temperatures, volume fractions of crystallized solid particles (ϕ), and the compositions of remaining liquid phase for 45 Coal Ash slag samples. The flow properties of completely liquid and partly crystallized Coal Ash slag samples have been predicted by three viscosity models. The Urbain formalism has been modified to describe the viscosities of fully liquid slag and homogeneous remaining liquid phase in Coal Ash slag samples. The modified Einstein equation and Einstein–Roscoe equation have been used to describe the viscosities of heterogeneous Coal Ash slag samples of ϕ < 10.00 vol % and ϕ ≥ 10.00 vol %, respectively. These three models provided a good description of the experimental data of fully liquid and heterogeneous Coal Ash slag samples. The new models also predicted flow properties of mixtures of Coal Ash slags with CaO, Fe2O3, MgO, SiO2, and Al2O3. © 2010 American Institute of Chemical Engineers AIChE J, 2011
R. Nishimura - One of the best experts on this subject based on the ideXlab platform.
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Effect of Coal Ash on sonochemical degradation of phenol in water
Ultrasonics sonochemistry, 2006Co-Authors: Hiroyuki Nakui, Kenji Okitsu, Yasuaki Maeda, R. NishimuraAbstract:The influences of Coal Ash on the degradation of phenol in water were investigated under the stirring or ultrasonic irradiation conditions. Phenol solution (10mg/L, 100mL) was sonicated at 200 kHz and 200 W with or without Coal Ash (53-106 microm in particle size and concentration of 0.0-1.5 wt%). It was found that the sonochemical degradation of phenol in the presence of Coal Ash was faster than that in the absence of Coal Ash, and the optimum amount of Coal Ash was a maximum at 0.4-0.6 wt%. It was confirmed that the phenol degradation did not occur by the addition of hydrogen peroxide and nitric acid under the stirring conditions. The sonochemical degradation with Coal Ash was depressed by the addition of tertiary butyl alcohol as a radical scavenger. These results indicated that the Coal Ash accelerated the phenol degradation due to the increase in the amount of hydroxyl radicals under the ultrasonic irradiation. Since the Coal Ash used had a porous and uneven surface, which was observed by SEM, it was assumed that the Coal Ash led to the increase in the nucleation site for cavitation bubble due to its surface roughness.