Coal reverse flotation. Part II: Cleaning of a subbituminous coal

An overview of reverse flotation process for coal

“…7(a)). In the second part of their work, Ding and Laskowski (2006b) found that at the same dosage the reject ash was more than 80% at reject yield between 35 and 40% ( Fig. 7(b)).…”

“…As stated above reverse coal flotation process has been tried for both sub-bituminous, lignite as well as oxidised coals (Pawlik and Laskowski, 2003b;Pawlik, 2002;Melo, 2005;Ding and Laskowski, 2006b;Patil and Laskowski, 2008;Vamvuka and Agridiotis, 2001;Zhang et al, 2013;Ozturk and Temel, 2013;) and satisfactory results have been found on the feasibility of the process for such coals. The main reason behind this can be attributed to the lesser hydrophobic nature of these coals which occur naturally.…”

“…(a) Effect of dextrin on reverse flotation of raw coal/gangue mixture (DTAC 6 kg/t, ferric silicate hydrosol 2 kg/t, pH 10.4, feed ash 48.5% (Ding and Laskowski, 2006a)). (b) Effect of dextrin on reverse flotation of raw coal (DTAC 1.375 kg/t, PAM 500 g/t, DTAC conditioning 0′, natural pH) (Ding and Laskowski, 2006b). Ding and Laskowski (2006a) showed that the addition of dextrin improved the quality of concentrate by reducing the ash content from 30.8% to 20.9% at a dosage of 1.5 kg/t (Fig.…”

“…8. Effect of PAM on reverse flotation of coal (DTAC 1.375 kg/t, dextrin 1 kg/t, tannic acid 1 kg/t, conditioning 0′, natural pH) (Ding and Laskowski, 2006b). activators for oxide and silicate minerals.…”

“…In the case of coal flotation, it is well known that best results are obtained at particle size below 300 μm. Essentially all of the work done on coal reverse flotation has abide by this either in the form of fully liberated feed as coal/gangue mixture (Stonestreet and Franzidis, 1988, 1992Pawlik and Laskowski, 2003a,b;Ding and Laskowski, 2006a) or finely ground coal samples (Melo, 2005;Ding and Laskowski, 2006b;Patil and Laskowski, 2008;Zhang et al, 2013;Pawlik, 2002;Vamvuka and Agridiotis, 2001). Vamvuka and Agridiotis (2001) studied the response of individual size fractions (+300 μm, −300 + 75 μm and −75 μm) using a mixture of kerosene having 2% DDA as collector and MIBC as frother.…”