摘要:

An improved experimental procedure to measure contact angle has been consolidated with coal surface preparation involving polishing with abrasive paper, alumina powder,and a cloth, followed by ultrasonic and mechanical cleaning. Specifically, the captivebubble measuring technique has been compared with the sessile-drop technique and the former has been recommended for the examination of the hydrophobic properties of coal surfaces. Results of the research program, which is currently under way, on the effect of the nature. amount, size, and distribution of mineral inclusions in coal on its wettability are briefly reviewed.

ISSN:0734-9343    

DOI:10.1080/07349340008945621

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Coal cleaning by selective agglomeration of an aqueous suspension of coal particles was demonstrated on a laboratory scale by employing a colloidal dispersion of microscopic gas bubbles as an agglomerant. The microbubbles were produced by saturating water with gas under pressure and then releasing the pressure as the water was agitated. The formation and stabilization of microbubbles was facilitated by employing a small amount of i-octane. Agglomeration was carried out in a closed system using a high shear rate and with no additional air present. The resulting agglomerates Boated readily since they consisted of a mixture of coal particles and microbubbles. Therefore, the agglomerates were recovered by allowing the treated material to separate into distinct layers under quiescent conditions. The upper product layer held most of the coal with greatly diminished ash content while the bottom layer was composed largely of ash-forming mineral matter. The effects of various process parameters were studied including solids concentration, i-octane concentration, and air saturation pressure. In addition, the results achieved with two agglomeration stages were compared with the results of a single stage.

ISSN:0734-9343    

DOI:10.1080/07349340008945622

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The handleability monitor has been specifically designed to provide a simple, rapid and on-site assessment of the whole or part consignment of a coal blend in its ‘ as-prepared’ or ‘ as-received’ condition. Evaluation has been carried out at a number of user' s coal-handling plants, on both metallurgical and power station coals from a variety of sources world-wide (Australia, South Africa, United Kingdom and USA). The results are used to predict which coals could routinely pass through a handling plant at line capacity, without causing blockage or delay, and have also been correlated with the operator' s perception of the coal' s handling characteristics and problems caused (blockages in chutes, hoppers, etc.) on the coal handling plant.

ISSN:0734-9343    

DOI:10.1080/07349340008945623

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Coal fines (-0.6 mm) are often cleaned using wet separation processes such as froth flotation. Dewatering of clean coal slurry is essential for marketing the product and reducing the transportation cost. Vacuum filtration is one of the most widely used processes for fine coal dewatering. However, the filter cake often contains more than 20% moisture demanded by the coal industry

ISSN:0734-9343    

DOI:10.1080/07349340008945624

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor