Abstract
Research has been carried out to obtain carbonaceous concentrate from ash from the combustion of Ekibastuz coals by the flotation method. To increase the efficiency of flotation, a preliminary chemical activation of ash in a sodium bicarbonate solution was used, which made it possible to change the phase composition and mineral structure. Upon activation, the phases of aluminum silicate-silymanite and hedenbergite disappeared, changes occurred in mullite towards a decrease in the content of silica in it, the content of free silica increased from 8.7 to 36.1 %, and the calcite phase appeared. As a result of studies, it was determined that the optimal temperature of chemical activation is 150 °C, a further increase in temperature leads to insignificant changes in the phase composition. At a temperature of 150 °C, phase transformations in ash are completed with a duration of 60 - 90 min. After chemical activation of the ash, the carbon content in the carbonaceous concentrate obtained during flotation doubled. The richest carbonaceous concentrate with a carbon content of 52.9 % was obtained using kerosene and MIBC (Methylisobutylcarbinol).
