The effects of solids and reagents on the characteristics of coal flotation in columns

Investigation of Effective Parameters on the Gas Holdup in Column Flotation of a Coal Tailing Sample

“…The effect of solids on the gas holdup in a flotation column had been considered by Zhou et al [11], Banisi et al [12], Ityokumbul et al [9], and Shukla et al [7]. It was observed that the addition of coal decreased the gas holdup [1,7]; however, it is not as significant as for the hydrophilic particles (calcite and silica).…”

“…It was observed that the addition of coal decreased the gas holdup [1,7]; however, it is not as significant as for the hydrophilic particles (calcite and silica). It was shown that in the absence of a collector, gas holdup increases with the solids addition [11]. Other studies have shown that the presence of solids had no effect on the gas holdup and flow regimes except when solids were observed on the gas distributor [9].…”

“…Also Zhou et al [11] indicates that the ratio of gas holdup is lower in the presence of Dowfroth 250 than MIBC. The effect of superficial gas velocity J g and superficial liquid rate on the gas holdup was investigated by Matiolo et al [8] and Shukla et al [7] in a flotation column using coal.…”

“…Also frothers obviously influence the kinetics of particle-bubble attachment and, therefore, flotation rate [11]. The effect of the frother on bubble dynamics and bubble size has been reported by a number of authors [5,8,9,20].…”

A review of induction and attachment times of wetting thin films between air bubbles and particles and its relevance in the separation of particles by flotation

“…It should be noted that for coals of different ranks, molybdenite and resins the measured attachment time as a function of particle size is dependent on the particle density because the slope in the diagram attachment time versus particle size becomes greater for those particles having higher particle density [25]. High hydrophobic coverage on the particle surface as well as a relatively small addition of frother in a collector solution improve attachment force between a particle and a bubble, and thus the stability of the particlebubble complex [86][87][88], reducing the attachment time for very large particles.…”