Unburned magnesium aluminate spinel refractories were prepared using sintered magnesium aluminate spinel as the main raw material,phenolic resin as the binder,aluminum powder(2%,4%,and 6%by mass)and silicon powder(whe...Unburned magnesium aluminate spinel refractories were prepared using sintered magnesium aluminate spinel as the main raw material,phenolic resin as the binder,aluminum powder(2%,4%,and 6%by mass)and silicon powder(when Al powder addition is 4%,Si powder addition varies:1%and 2%,by mass)as additives.The effects of the Al powder and Si powder additions on the properties and microstructure of the refractories heat treated at different temperatures(1000,1400,and 1600℃for 3 h)were studied.The results show that the Al powder addition can greatly enhance the cold modulus of rupture of the samples fired at 1000 or 1400℃,and meanwhile AlN reinforcement phase forms in the matrix,which greatly improves the hot modulus of rupture of the samples at 1400℃;however,the heat treatment at 1600℃has little influence on the strength;the addition of Al powder and Si powder results in the formation of low melting point phases,greatly reducing the hot modulus of rupture.However,the low melting point phases promote sintering,which enhances the density and the cold modulus of rupture,and decreases the volume change during heating.The samples added with Al and Si all have higher cold modulus of rupture than those added with Al powder only.展开更多
The combustion characteristics of two kinds of unburned pulverized coal (UPC) made from bituminous coal and anthracite were investigated by thermogravimetric analysis under air. The reaction kinetics mechanisms betwee...The combustion characteristics of two kinds of unburned pulverized coal (UPC) made from bituminous coal and anthracite were investigated by thermogravimetric analysis under air. The reaction kinetics mechanisms between UPC and CO2 in an isothermal experiment in the temperature range 1000–1100°C were investigated. The combustion performance of unburned pulverized coal made from bituminous coal (BUPC) was better than that of unburned pulverized coal made from anthracite (AUPC). The combustion characteristic indexes (S) of BUPC and AUPC are 0.47 × 10^-6 and 0.34 × 10^-6 %2·min^-2·°C^-3, respectively, and the combustion reaction apparent activation energies are 91.94 and 102.63 kJ·mol^-1, respectively. The reaction mechanism of BUPC with CO2 is random nucleation and growth, and the apparent activation energy is 96.24 kJ·mol^-1. By contrast, the reaction mechanism of AUPC with CO2 follows the shrinkage spherical function model and the apparent activation energy is 133.55 kJ·mol^-1.展开更多
Numerical simulation of the content of unburned carbon in fly ash on the 300MW tangentially pulverized coal fired boiler is performed by the numerical simulation software COALFIRE, which is based on international adva...Numerical simulation of the content of unburned carbon in fly ash on the 300MW tangentially pulverized coal fired boiler is performed by the numerical simulation software COALFIRE, which is based on international advanced TASCFLOW software platform. Firstly, take the result of calculation of number value as the sample, and then set up the support vector machine model of unburned carbon content on the boiler. The relative error between the predicted output and measured value is 0.00186%, which proves the modeling is good for the unburned carbon in fly ash predict.展开更多
The study deals with adsorption of Naphthol Green B on two unburned carbons and the parent coal,from which the UCs have been created in a fluidised-bed power station.Particular attention has been paid to the adsorptio...The study deals with adsorption of Naphthol Green B on two unburned carbons and the parent coal,from which the UCs have been created in a fluidised-bed power station.Particular attention has been paid to the adsorption equilibrium modelling:experimental data has been analysed using 2-parameter(Langmuir,Freundlich) and3-parameter(Redlich-Peterson) isotherms — both linear and non-linear regressions have been used for the estimation of the isotherm parameters.In the case of both UCs,the Langmuir isotherm model provides the worst fit,whereas 2-parameter Freundlich and 3-parameter Redlich-Peterson models are both good,from which 3-parameter Redlich-Peterson isotherm provides slightly better results(despite the penalty used for the higher number of parameters).In the case of both UCs,the linear regression of Freundlich and Redlich-Peterson models provides good results(comparable with non-linear regressions).Unlike both UCs,the best fit of the experimental data from the adsorption on the coal has been achieved by the Langmuir isotherm model.The results based on the Freundlich or Redlich-Peterson model were(in this case) somewhat worse.展开更多
为解决矿物凝聚除藻技术不能同步除氮除磷、材料易散失、底泥量大、去除效果持续性短等弊端,对11种矿物材料进行吸附去除NH_(4)^(+)-N、TP、Chl-a和TUB的性能测定筛选,以吸附NH_(4)^(+)-N效果最好的绿沸石为基础材料,制备5种免烧类绿沸...为解决矿物凝聚除藻技术不能同步除氮除磷、材料易散失、底泥量大、去除效果持续性短等弊端,对11种矿物材料进行吸附去除NH_(4)^(+)-N、TP、Chl-a和TUB的性能测定筛选,以吸附NH_(4)^(+)-N效果最好的绿沸石为基础材料,制备5种免烧类绿沸石基复合材料(NGZC),分析NGZC的表面形貌结构,探讨了发泡剂和水泥用量、绿沸石与其余矿物的物料比等因素对NGZC净水性能的影响,以及NGZC投加量、水处理反应温度和时间等因素对去除河道污水中多种污染物效果的影响。结果表明,在设定的养护条件下,NGZC最佳制备条件为:水泥掺量为10%~15%,发泡剂掺量为0.25%~0.5%,绿沸石与牡蛎壳、凹凸棒石黏土、活性白土、水滑石、赤玉土的物料比分别为8∶2、4∶6、6∶4、4∶6、4∶6。最佳水处理条件为:25℃下,200 mL污染河水中加4 g NGZC,处理3 d。本研究为藻型富营养化水体的污染修复、非金属矿物和废弃物的资源化利用和水土保持等提供低成本的复合净水材料和新技术。展开更多
文摘Unburned magnesium aluminate spinel refractories were prepared using sintered magnesium aluminate spinel as the main raw material,phenolic resin as the binder,aluminum powder(2%,4%,and 6%by mass)and silicon powder(when Al powder addition is 4%,Si powder addition varies:1%and 2%,by mass)as additives.The effects of the Al powder and Si powder additions on the properties and microstructure of the refractories heat treated at different temperatures(1000,1400,and 1600℃for 3 h)were studied.The results show that the Al powder addition can greatly enhance the cold modulus of rupture of the samples fired at 1000 or 1400℃,and meanwhile AlN reinforcement phase forms in the matrix,which greatly improves the hot modulus of rupture of the samples at 1400℃;however,the heat treatment at 1600℃has little influence on the strength;the addition of Al powder and Si powder results in the formation of low melting point phases,greatly reducing the hot modulus of rupture.However,the low melting point phases promote sintering,which enhances the density and the cold modulus of rupture,and decreases the volume change during heating.The samples added with Al and Si all have higher cold modulus of rupture than those added with Al powder only.
基金financially supported by the National Natural Science Foundation of China (Nos. 51874080, 51604069, and 51774071)the Fundamental Research Funds for the Central Universities, China (No. N162504004)
文摘The combustion characteristics of two kinds of unburned pulverized coal (UPC) made from bituminous coal and anthracite were investigated by thermogravimetric analysis under air. The reaction kinetics mechanisms between UPC and CO2 in an isothermal experiment in the temperature range 1000–1100°C were investigated. The combustion performance of unburned pulverized coal made from bituminous coal (BUPC) was better than that of unburned pulverized coal made from anthracite (AUPC). The combustion characteristic indexes (S) of BUPC and AUPC are 0.47 × 10^-6 and 0.34 × 10^-6 %2·min^-2·°C^-3, respectively, and the combustion reaction apparent activation energies are 91.94 and 102.63 kJ·mol^-1, respectively. The reaction mechanism of BUPC with CO2 is random nucleation and growth, and the apparent activation energy is 96.24 kJ·mol^-1. By contrast, the reaction mechanism of AUPC with CO2 follows the shrinkage spherical function model and the apparent activation energy is 133.55 kJ·mol^-1.
文摘Numerical simulation of the content of unburned carbon in fly ash on the 300MW tangentially pulverized coal fired boiler is performed by the numerical simulation software COALFIRE, which is based on international advanced TASCFLOW software platform. Firstly, take the result of calculation of number value as the sample, and then set up the support vector machine model of unburned carbon content on the boiler. The relative error between the predicted output and measured value is 0.00186%, which proves the modeling is good for the unburned carbon in fly ash predict.
基金Supported by the project No.LO1404(Sustainable Development of Center ENET-Energy Units for the Utilization of Non-Traditional Energy Sources)project No.LO 1203(Regional Materials Science and Technology Centre-Feasibility Program)+1 种基金the project No.LO1406(Institute of Clean Technologies for Mining and Utilization of Raw Materials for Energy Use-Sustainability Programsupported by the National Programme for Sustainability I 2013-2020
文摘The study deals with adsorption of Naphthol Green B on two unburned carbons and the parent coal,from which the UCs have been created in a fluidised-bed power station.Particular attention has been paid to the adsorption equilibrium modelling:experimental data has been analysed using 2-parameter(Langmuir,Freundlich) and3-parameter(Redlich-Peterson) isotherms — both linear and non-linear regressions have been used for the estimation of the isotherm parameters.In the case of both UCs,the Langmuir isotherm model provides the worst fit,whereas 2-parameter Freundlich and 3-parameter Redlich-Peterson models are both good,from which 3-parameter Redlich-Peterson isotherm provides slightly better results(despite the penalty used for the higher number of parameters).In the case of both UCs,the linear regression of Freundlich and Redlich-Peterson models provides good results(comparable with non-linear regressions).Unlike both UCs,the best fit of the experimental data from the adsorption on the coal has been achieved by the Langmuir isotherm model.The results based on the Freundlich or Redlich-Peterson model were(in this case) somewhat worse.
文摘为解决矿物凝聚除藻技术不能同步除氮除磷、材料易散失、底泥量大、去除效果持续性短等弊端,对11种矿物材料进行吸附去除NH_(4)^(+)-N、TP、Chl-a和TUB的性能测定筛选,以吸附NH_(4)^(+)-N效果最好的绿沸石为基础材料,制备5种免烧类绿沸石基复合材料(NGZC),分析NGZC的表面形貌结构,探讨了发泡剂和水泥用量、绿沸石与其余矿物的物料比等因素对NGZC净水性能的影响,以及NGZC投加量、水处理反应温度和时间等因素对去除河道污水中多种污染物效果的影响。结果表明,在设定的养护条件下,NGZC最佳制备条件为:水泥掺量为10%~15%,发泡剂掺量为0.25%~0.5%,绿沸石与牡蛎壳、凹凸棒石黏土、活性白土、水滑石、赤玉土的物料比分别为8∶2、4∶6、6∶4、4∶6、4∶6。最佳水处理条件为:25℃下,200 mL污染河水中加4 g NGZC,处理3 d。本研究为藻型富营养化水体的污染修复、非金属矿物和废弃物的资源化利用和水土保持等提供低成本的复合净水材料和新技术。
