OPTIMISATION OF REAGENT TYPE BASED ON PETROGRAPHIC STUDIES IN FLOTATION PROCESS AT CENTRAL ALBORZ COAL WASHING PLANT

摘要

The choice of coal washing method depends on physical and chemical characteristics as well as physicochemical behaviour of the coal components, i.e. macerais and their impurities. Most of the studies regarding coke making process in the last few decades have been directed towards coal blends with suitable proportions of reactive constituents, i.e. vitrinite and liptinite, and also inert constituents, i.e. inertinite. Different changes in size and petrographic composition of coal result in different behaviours in flotation process. In this study, effects of petrographic composition and particle size on flotation process were investigated. To get the best results, different reagents were selected as collectors and frothers based on a petrographie study. The aim was to produce coal concentrates suitable for feeding the coking plant. Samples were taken from rougher and cleaner cells of Central Alborz Coal Washing Plant (Iran). The petrographie study showed that, with the same frother, by applying gasoline as a collector, yield and total recovery increased by 3.5 and 3%, respectively, as compared to those when kerosene served as collector. Continuing with gasoline as collector, total circuit recovery increased by 2.2% when Methyl Isobutyl Carbinol (MIBC), rather than pine oil, served as frother. Based on petrographie studies and percentages of reactive macerais, the optimum reagents were found to be gasoline (as collector) and MIBC (as frother).