Search

This study has been carried out on the upgradation of low-grade coals of Akkakhel, Akhorwal and Shekhan areas in western Khyber Pakhtunkhwa, Pakistan. The coals of these areas, because of high ash and sulfur contents and low Gross Calorific Values (GCV) are being mined on small scale for domestic purposes only. In this work, attempts have been made to reduce sulfur and ash contents from high ash and sulfur coal which will ultimately increase the fixed carbon and GCV of the studied coal from aforementioned coal mines by froth flotation technique. During this technique, the use of kerosene as a collector and pine oil as a frother at various particle sizes (i.e., -80, -100 and -140 mesh) has decreased ash and sulfur contents in the studied coal samples. The optimum process parameters were established at -140 mesh particle size with 20 % solids in floation pulp at pH 9. Under these conditions ash was reduced from 40.6 to 13.8% (66 % reduction) and sulfur from 3.97 to 1.51% (62 % reduction) while the GCV was enhanced from 7070 to 7963 kcal/kg in the coal samples of Akkakhel area. In the coal samples of Akhorwal area, ash was reduced from 35 to 18.16% (48.11% reduction) and sulfur from 6.31 to 3.51% (44.37% reduction) while the GCV was enhanced from 5500 to 6108 kcal/ kg. Similarly, in the coal samples of Shekhan area, ash was reduced from 41.6 to 20.1% (51.68% reduction) and sulfur from 3.1 to 1.5% (51.61% reduction) while the GCV was enhanced from 3995 to 4941 kcal/ kg. The final upgraded product was found suitable for use in power plants, boilers, and cement industries etc. [ABSTRACT FROM AUTHOR]

Khyber Pakhtun Khwa province of Pakistan has considerable amounts of low ranked coal. However, due to the absence of any centrally administered power generation system there is a need to explore indigenous methods for effectively using this valuable energy resource. In the present study an indigenous coal briquetting technology has been developed and evaluated in terms of combustion characteristics such as moisture content, volatile matter, ash, fixed carbon and calorific value of the resulting coal briquette and disintegration strength using polyvinyl acetate (PVA) in combination with calcium carbonate (sample no 3 with highest disintegration strength value of 2059N). Comparison of test samples with the commercially available coal briquettes revealed improved combustion characteristics for the PVA bonded (sample no 1 and 5) coal briquettes having higher fixed carbon content and calorific value, lower ash contents as well as lower initial ignition time. [ABSTRACT FROM AUTHOR]