Synergistic effect of SPS compound surfactant and diesel oil on low-rank coal slime flotation

In order to improve the collection performance of diesel oil on low-rank coal slime flotation, SPS (Span80, Polysorbate, sodium dodecyl sulfate) composite emulsifier was mixed with diesel fuel to prepare SPS microemulsion, as a collector for coal slime flotation. When the ratio of SPS emulsifier to diesel oil is 1:2, clean coal yield and the combustible recovery reached the highest, they were 50.16% and 82.65%, respectively. Through Contact angle test, Zeta potential analysis, EDLVO theoretical calculation, the mechanism of SPS microemulsion improving the flotation effect of low-rank coal slime was discussed. The Synergistic adsorption of SPS emulsifier and diesel oil on coal surface increases the coal surface contact Angle by 24.8°, increase the absolute value of Zeta potential on coal surface in solution by 9.14 mV, the energy barrier of the total interaction energy (VT) was increased from 8.4 × 10−18J to 9.8 × 10−18J. The coal particles treated by SPS microemulsion have the best dispersion and contact with collector droplets more fully. SPS microemulsion can be used as a new collector for low-rank coal slime flotation.