Interaction of Acetylenic Alcohols with the Coal’s Surface during Flotation

摘要

Abstract If acetylenic alcohols are used as flotation reagents for coal, coal extraction in the concentrates is increased, the concentrate yield is improved, and the flotation time is decreased in relation to methods commonly employed. Acetylenic alcohols are good frothing agents, and so the use of traditional frothing elements may be minimized or eliminated. Thanks to their active reaction with the coal’s organic mass, the use of traditional collection agents may also be minimized or eliminated. Extraction is improved even for highly oxidized coal, depending on its rank and metamorphic stage. In all the experiments, the flotation time is decreased by a factor of 1.25–1.6. The slight increase in ash content of the concentrates on flotation in the presence of dimethyl(isopropenylethynyl)carbinol (DMIPEK reagent) may be due not only to excess gas oil and nonoptimal flotation conditions but also to the structure of coal of different ranks and metamorphic stages. Computer simulation shows that the interaction of acetylenic alcohol molecules with fragments of the coal’s organic mass containing double bonds is accompanied by stepwise complex formation, culminating in the appearance of a covalent bond. That permits preliminary prediction of the results obtained in coal flotation using acetylene reagents.