“…the mineral matter was floated and reported in the froth phase while the clean coal was depressed and remained in the suspension. The concept was further developed for the selective removal of pyritic sulphur from US coals by several investigators (Baker et al, 1973;Miller, 1973Miller, , 1975Miller and Deurbrouck, 1982;Lin, 1982;Miller et al, 1984). Consequently the study of reverse flotation of coal with a motive to lower the ash content of coal was carried out by many scientists and researchers (Stonestreet and Franzidis, 1988, 1992Vamvuka and Agridiotis, 2001;Pawlik and Laskowski, 2003a,b;Melo, 2005;Ding and Laskowski, 2006a,b;Patil andLaskowski, 2008, Zhang et al, 2013;Ozturk and Temel, 2013;.…”