Comparison by g.c.-m.s. of liquefaction extracts from coal maceral concentrates

Abstract

Dodecylamine (DDA) is a commonly used collector in the froth flotation of quartz particles. The present work for the first time studies the effect of DDA nanobubbles (NBs) on the flotation of coarse particles (−425 + 300 μm, −300 + 212 μm and − 212 + 106 μm). For this purpose, 50 mg/l DDA was employed as a primary material for producing bulk NBs via hydrodynamic cavitation technique to be used in the flotation kinetics tests. For comparative purposes, pine oil (PO), Methyl Isobutyl Carbinol (MIBC) and polypropylene glycol (A65) with a concentration of 22.4 mg/l were utilized for generating NBs and also as a frother. According to the results, generated NBs categorized based on the stability and mean bubble size as DDA > PO > MIBC>A65. The flotation rate constants (k) and ultimate recoveries (Rmax) obtained in the presence of the DDA-NBs were substantially improved compared to the corresponding values given for the frother types NBs. That was mainly related to the chemical functionality of the agent together with its extended stability. The experimental results showed a Rmax of 97.5% using the DDA-NBs in the condition of without any frother; however, the highest recovery using common air bubbles (CBs) was obtained 90.8% by the PO. Additionally, the influential order of the three frothers and the DDA on flotation rate constant was shown as DDA > PO > MIBC>A65 for each fraction size. Finally, the results indicated that the k and Rmax of coarse particles were improved by 22% and 21% in the presence of the DDA-NBs.