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71.
72.
E.I. Vargha-Butler T.K. Zubovits D.R. Absolom A.W. Neumann H.A. Hamza 《Chemical Engineering Communications》1985,33(5):255-276
The sedimentation volume, Vsed, of coal particles in mixtures of pairs of non-polar and more polar organic liquid combinations as well as in aqueous solutions was determined at 20°C.
The liquid combinations were chosen such that the surface tension, γSV, of the coal particles fell between the surface tensions, γLV, of the two liquids. A constant mass of a given coal sample was suspended in constant volumes of liquid mixtures of different concentrations.
It was found that the sedimentation volume changed with varying composition of the liquid mixtures, as did the surface tension. A maximum or a minimum occurred in Vsed when the surface tension of the suspending liquid was equal to that of the coal particles, i.e. when γLV = γSV. Maxima occurred in more polar and minima in the non-polar or less polar liquid mixtures. The position of the extrema, and hence the surface tension, γsv, of the particles, was found to change with particle size, in agreement with findings from other independent techniques.
It was found that the surface tension of coal, γsv, depends on the surrounding liquid, i.e. coal is hydrophobic in organic and hydrophilic in aqueous media, again in agreement with the results from other techniques. 相似文献
The liquid combinations were chosen such that the surface tension, γSV, of the coal particles fell between the surface tensions, γLV, of the two liquids. A constant mass of a given coal sample was suspended in constant volumes of liquid mixtures of different concentrations.
It was found that the sedimentation volume changed with varying composition of the liquid mixtures, as did the surface tension. A maximum or a minimum occurred in Vsed when the surface tension of the suspending liquid was equal to that of the coal particles, i.e. when γLV = γSV. Maxima occurred in more polar and minima in the non-polar or less polar liquid mixtures. The position of the extrema, and hence the surface tension, γsv, of the particles, was found to change with particle size, in agreement with findings from other independent techniques.
It was found that the surface tension of coal, γsv, depends on the surrounding liquid, i.e. coal is hydrophobic in organic and hydrophilic in aqueous media, again in agreement with the results from other techniques. 相似文献
73.
吴式瑜 《煤炭加工与综合利用》2004,(3):5-8
简述了孙家沟选煤厂工艺参数的选择和设计情况及投产后的运行效果,评价认为,该厂建设速度快,工艺流程合理,设备性能良好,产品质量合格、稳定。 相似文献
74.
D.K. Fidaros 《Powder Technology》2007,171(2):81-95
Controlling the calcination process in industrial cement kilns is of particular importance because it affects fuel consumption, pollutant emission and the final cement quality. Therefore, understanding the mechanisms of flow and transport phenomena in the calciner is important for efficient cement production. The main physico-chemical processes taking place in the calciner are coal combustion and the strongly endothermic calcination reaction of the raw materials. In this paper a numerical model and a parametric study are presented of the flow and transport processes taking place in an industrial calciner. The numerical model is based on the solution of the Navier-Stokes equations for the gas flow, and on Lagrangean dynamics for the discrete particles. All necessary mathematical models were developed and incorporated into a computational fluid dynamics model with the influence of turbulence simulated by a two-equation (k-ε) model. Distributions of fluid velocities, temperatures and concentrations of the reactants and products as well as the trajectories of particles and their interaction with the gas phase are calculated. The results of the present parametric study allow estimations to be made and conclusions to be drawn that help in the optimization of a given calciner. 相似文献
75.
简要介绍了煤矸石的构成、来源及危害;论述了煤矸石在耐火材料中的可行性分析研究;详细阐述了煤矸石在耐火材料中的研究和应用现状,及其对未来的展望。 相似文献
76.
Application of the Box-Wilson experimental design method for the spherical oil agglomeration of coal
Yakup Cebeci 《Fuel》2006,85(3):289-297
In this study, the Box-Wilson statistical experimental design method was employed to evaluate the effects of important variables such as bridging liquid (oil) concentration, salt (CaCl2·2H2O) concentration and stirring speed on the agglomeration of bituminous coal. Response function coefficients were determined by the regression analysis of experimental data and the predictions were found to be in good agreement with the experimental results. The optimum kerosene concentration, CaCl2·2H2O concentration and stirring speed were determined as 30 wt%, 1 M and 1683 rpm, respectively, when considering combustible recovery and ash content.In addition, contact angle and solution surface tension measurements were carried out to evaluate of agglomeration success with the contact angle values and surface tension values. The surface tension of CaCl2 2H2O solutions and the average contact angle increased with increasing CaCl2·2H2O concentration. 相似文献
77.
Identification of organochlorines and organobromines in coals 总被引:1,自引:0,他引:1
Xian-Yong Wei Xiao-Hua Wang Zhi-Min Zong Zhong-Hai Ni Li-Fang Zhang Ya-Fei Ji Ke-Chang Xie Chul Wee Lee Zhen-Xue Liu Nai-Bo Chu Jiao-Ying Cui 《Fuel》2004,83(17-18):2435-2438
Four Chinese bituminous coals were extracted with CS2, n-hexane, benzene, methanol, acetone, tetrahydrofuran (THF) and THF/methanol (1: 3 vol/vol) mixed solvent sequentially. The resulting 28 extracts were analyzed with GC/MS. Six organochlorines (OCs) and two organobromines (OBs) were identified in eight extracts from the coals. Our experiments provide, for the first time, the information on the molecular structure of OCs and OBs in coals. 相似文献
78.
Zhiheng Wu 《Fuel》2007,86(14):2194-2200
A UK bituminous coal has been used to study demineralization by two-stage chemical leaching. The first-stage uses hydrofluoric acid (HF) at 65 °C and reduces the ash content from 5.30 wt% to 1.37 wt% by mainly removing Al and Si containing minerals. Subsequent leaching by ferric ions decreases the ash content further to 990 ppm by removing most of the pyrite and fluorides formed during the HF leaching. Calorific value of the coal shows no change following leaching, which suggests no oxidation is occurring to the coal carbonaceous matrix. The mercury and sulfur contents after the two-stage leaching sequence decrease by 40% and 26%, respectively. 相似文献
79.
掺煤矸石的水泥性能与颗粒群分布的关系研究 总被引:2,自引:0,他引:2
将不同细度的煤矸石、纯硅酸盐水泥分别按30%和70%的比例混合,测其胶砂流动度、净浆标准稠度用水量和3d、28d胶砂抗压强度。以宏观性能指标为z轴,水泥与煤矸石的中位径D50之差为x轴,水泥与煤矸石混合样的中位径D50为y轴,进行三维区域图分析。给出各项性能指标发展趋势与水泥、煤矸石的相对位置以及混合体系总体细度的相互关系。 相似文献
80.
煤矸石用作农肥的几个问题 总被引:3,自引:0,他引:3
通过对平顶山矿区煤矸石的微量营养元素、粒度与酸碱度及煤矸石中的有害元素的分析测定,在综合国内外煤矸石研究资料的基础上,笔者认为平顶山矿区煤矸石可用作农肥。煤矸石的这种用途不仅可获得较大的经济效益,而且还具有明显的社会效益和环境效益。 相似文献