Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia):
Petukhov V. N., Professor, Doctor of Engineering Sciences, chief.petuhov2013@yandex.ru
Chizhevskiy V. B., Professor, Doctor of Engineering Sciences
Voloshchuk T. G., Associate Professor, Candidate of Engineering Sciences, votagen@mail.ru

Coal flotation with the use of additional modifying agents is studied. The modifiers used are represented by vinyl pyridine copolymers with alkyl sulfoxides. With the modifier flow of 0.5–1.0 g per ton of coal fines, the combustible recovery into the concentrate increases, with improved process selectivity and reduced coal organic mass losses with flotation tailings. The effectiveness of these modifiers was evaluated by the number of sulfo groups and vinylpyridine groups per macromolecule of the chemical compound and by the molecular weight of the modifier. The highest flotation rates were obtained for the modifier with the molecular weight of 20,000. With equal collector and frother consumption rates, the use of an additional modifier leads to an increase in combustible recovery into the concentrate by 2.1–3.2 %, depending on coal mineralization and collector flow rates. It is established that collector consumption may be reduced by 20.0–40.0 %, with improved flotation performance. Increased flotation efficiency, when a modifier is introduced into the process, is explained by its adsorption on energy-active sections of the coal surface due to hydrogen bonding by copolymer polar groups, with the orientation of hydrocarbon groups to the aqueous phase, thereby improving coal hydrophobic behavior and organic mass floatability of the coals. It is established that modifier effectiveness increases when it is fed into the flotation process before the collector.

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