Upgrading low-rank lignite coals (Çan, Çanakkale/Turkey) by leaching

Abstract

ABSTRACT Reserve of quality coal mines has been getting decreased all over the world, as well as Turkey. Presently, there is a concentrated effort in academia conducting intensive studies aimed at enhancing the quality of low-rank coals for utilization. Turkish lignite, containing high sulfur and ash, can be treated to remove sulfur and ash from the coal using physical, chemical, and biological methods. In this study, chemical (humic acid) and biological (Pseudomonas putida) leaching methods were applied for removing of pyritic and organic sulfur from a high sulfur content lignite coal taken from Çan (Turkish Coal Enterprises (TKI), Çanakkale, Turkey) region. The experimental study consisted of the two main stages as (i) column chemical leaching and bioleaching, and (ii) a combination of chemical and biological process at atmospheric pressure on physically the treated/cleaned lignite coal by heavy media separation. A clean coal product with 4.40% ash and 2.09% S content was obtained by both using chemical and biological leaching to the lignite coal treated/washed (16.46% ash and 6.14% S).