New Flotation Reagents on the Base of Tetrahydropyran for the Processing of High-Ash Coals

Abstract

The given paper presents the study results of flotation benefication of high-ash coals with new flotation reagent on the base of acetate of 3-amyltetrahydro-pyran- 4-ol which incorporates apolar and heteropolar groups. The use of a picric acid as a catalyst of hydroxymethylation reaction instead of sulfuric acid made it possible to halve the synthesis time and increase the yield of the target product. The structure of the obtained heterocyclic compound was identified by elemental analysis, infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Waste of high-ash coal production from the Saryadyr deposit (Kazakhstan) was selected as an object of flotation. It is found that the benefication process efficiency depends on the fineness of the coal material and increases with the transition from -0.8 + 0.4 mm to -0.2 + 0.08 mm. Comparison of the efficiency of coal flotation using pine oil as a traditional collector and 3-amyltetrahydropyran-4-ol acetate showed an increase in the degree of extraction of coal mass into a concentrate and a simultaneous decrease in its ash content when using a synthesized heterocyclic compound. It is concluded that 3-amyltetrahydropyran-4-ol acetate shows both a modifying effect and a foaming ability.