摘要:

X-ray computed tomography (CT) has been shown to be an excellent tool for the study of internal structure and multiphase texture of solids in a noninvasive, nondestructive manner. Now with new reconstruction algorithms and advanced computer systems, quantitative CT analysis is possible. In this regard, a step-by-step procedure for the determination of coal particle density by X-ray CT has been developed. Using appropriate algorithms, the feasibility of the construction of coal washability curves by quantitative X-ray CT analysis has been demonstrated

ISSN:0734-9343    

DOI:10.1080/07349349108960560

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Understanding the nature of coal surface heterogeneity is a prerequisite to accurate characterization and efficient control of coal surfaces. A new approach based on film flotation has led to estimation of surface energy distributions in individual coal particles. Changes in the distribution of surface sites due to oxidation and polyacrylamide adsorption on coal is studied here using the above approach. New information on possible conformations of adsorbed polymers is also obtained

ISSN:0734-9343    

DOI:10.1080/07349349108960561

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The flotability of Argonne Premium coals varying in rank has been correlated with the intrinsic moisture content and dielectric properties of the intrinsic water. It is shown that as the coal rank increases the intrisic moisture and dielectric constant of the coals decreases. The nature of intrinsic water present in the coal of different ranks has been characterized using a dielectric mixture model. The water present in lignite is different from that of sub-bituminous and bituminous coals. The flotability of coals of various ranks is explained in terms of the nature and extent of the intrinsic water

ISSN:0734-9343    

DOI:10.1080/07349349108960562

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

An extensive experimental study was conducted to investigate the effect of grinding conditions on the performance of a selective agglomeration process using n-pentane as agglomerant. Upper Freeport, Pittsburgh # 8, and Illinois # 6 coal samples were dry and wet ground to 28 mesh × 0 and 200 mesh × 0 particle sizes using a pulverizer, a ceramic jar mill, and a specially designed stirred-ball mill. The ground ;, samples were subjected to a standardized agglomeration test procedure using a Waring blender as the agglomeration unit. The effects of various operating variables, such as n-pentane to coal ratio, slurry concentration, mixing speed, and agglomeration time on energy recovery and ash rejection were statistically evaluated. The agglomeration test data showed dramatic differences between wet and dry grinding methods and between 28 mesh × 0 and 200 mesh × 0 particle sizes. Grinding to 200 mesh × 0 resulted in higher energy recoveries. Moreover, 200 mesh × 0 particle size obtained with wet grinding showed superior ash rejections when compared with those obtained through dry grinding

ISSN:0734-9343    

DOI:10.1080/07349349108960563

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Results obtained from batch flotation experiments on seven coal samples, having widely varying size and size-wise ash distributions have been used to develop a simple empirical model for predicting the performance through first order kinetic behaviour. The kinetic equation describing the variation of recoveries of non-ash and ash materials with flotation time is given as

ISSN:0734-9343    

DOI:10.1080/07349349108960564

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Fine coal cleaning by froth flotation in a 2-inch air-sparged hydrocyclone (ASH) has been investigated and the effects of important design and operating variables on separation efficiency examined. In order to reduce the complexity of the analysis, the flotation performance of the air-sparged hydrocyclone was studied by dimensionless analysis. As a result of these efforts, an empirical model was derived to predict the flotation effectiveness of the air-sparged hydrocyclone unit of various levels of design and operating variables, thus allowing for optimization of the flotation separation. Since the model is based on dimensionless analysis, it is anticipated that subsequent development efforts to scale-up the ASH flotation system for industrial utilization will be facilitated

ISSN:0734-9343    

DOI:10.1080/07349349108960565

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The removal of sulfur from Mequinenza (Spanish) lignite was investigated by hydrodesulfurization reactions. This lignite has an unusually high sulfur content, 9.9% (dry basis) of which about 90% is organic sulfur. The lignite was impregnated with nickel sulfate prior to reactions, at various levels of nickel loading. The reactions were performed in bench-scale microautoclave reactors in 6.9 MPa hydrogen at 250-325° C for 1 hour. The best result was the removal of 63% of the sulfur in the lignite, achieved with 1.5% nickel loading at 325° C. Compared to reactions without impregnated catalyst, the addition of nickel sulfate enhances the hydrodesulfurization at all reaction temperatures, and improves the selectivity to H2S. A high selectivity to H2S minimizes the formation of organic sulfur compounds in by-product liquids

ISSN:0734-9343    

DOI:10.1080/07349349108960566

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The relatively fine size consist of western Canadian coals can occasionally contribute to dustiness. Coal dustiness is generally evaluated on the basis of the ASTM test D547. However, the ASTM test is often inadequate when one is determining the effectiveness of dust control agents in field situations and this has prompted the development of several alternatives

ISSN:0734-9343    

DOI:10.1080/07349349108960567

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0734-9343    

DOI:10.1080/07349349108960568

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0734-9343    

DOI:10.1080/07349349108960569

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor