Extraction of carbon sorbents from aqueous solutions

Abstract

Ways to enhance effectiveness of carbon sorbents extraction from aqueous solutions of sodium chloride and sulfate salts by the electroflotation method after sorption in static mode are identified. It was found that the low degree of extraction of carbon materials from the sulfate- ion containing solutions is associated with the specific sulfate- ion adsorption on the surface of the coals, leading to a significant reduction in the electrokinetic potential of the particles to –30 mV. Sorbed on the surface of coal particles, Fe3+ cations shift their electrokinetic potential to the positive field, which contributes to the intensification of electroflotation extraction of carbon material from acidic solutions (pH 4–5). To increase the degree of extraction of powdered and granular coals, organic additives (surfactants, flocculants) are selected, which allow not only to intensify the process, but also to increase the amount of extracted powdered coals to 1 g/l, granular – to 0.6 g/l. Experiments aims to assess the effectiveness of the electroflotation method in the extraction of carbon materials of various types have shown that the use of this method should result not only to reduce the duration of the process from several hours to 10–20 minutes, but also increase the degree of coal recovery from 65–70 to 96–99% (according on the type of coal and conditions) in comparison with sedimentation in the presence of a coagulant.This research was funded by D.Mendeleev University of Chemical Technology of Russia. Project No.: З-2020-003.