Title: Upgradation of Mianwali coal using froth flotation and nitric acid leaching

Authors: Qura-Tul-Ain Rana; Rubab Arif; Khurram Shahzad; Javaid Akhtar; Naseer Sheikh; Shahid Munir

Addresses: Centre for Coal Technology, University of the Punjab, Lahore, Pakistan ' Centre for Coal Technology, University of the Punjab, Lahore, Pakistan ' Centre for Coal Technology, University of the Punjab, Lahore, Pakistan ' Centre for Coal Technology, University of the Punjab, Lahore, Pakistan ' Centre for Coal Technology, University of the Punjab, Lahore, Pakistan ' Centre for Coal Technology, University of the Punjab, Lahore, Pakistan

Abstract: Mianwali coal was upgraded using flotation process followed by acid leaching. For flotation tests parameters such as pH, impeller speed, solids in pulp and particle size were investigated. The results from flotation study were as: 54.1% increase in total carbon, 28.9% reduction in ash and 33.4% reduction in sulphur. Leaching tests on flotation concentrate were carried out to further improve the grade of coal. Test conditions for leaching were: acid concentration, leaching time, stirring rate and temperature. At optimum leaching conditions ash was reduced by 39.2% and sulphur by 59.76%. As a result of two cleaning techniques, overall reduction in ash and sulphur were found to be 57.38% and 74.2% respectively. Final ash and sulphur contents in clean coal were found to be 15.2% and 1.65% respectively. The clean coal, thus obtained can preferably be used in power plants and cement industry in the country. [Received: October 26, 2016; Accepted: May 24, 2017]

Keywords: beneficiation; froth flotation; Pakistani coal; nitric acid leachin.

DOI: 10.1504/IJOGCT.2019.099173

International Journal of Oil, Gas and Coal Technology, 2019 Vol.20 No.4, pp.463 - 472

Received: 21 Jun 2016
Accepted: 11 Jun 2017

Published online: 19 Apr 2019 *

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