In this study, a new jet-stirring coupling flotation device that incorporates the advantages of three conventional flotation machines (specifically, Jameson cell, mechanical flotation cell, flotation column) was designed based on jet suction. The suction capacity of a double cosine self-aspirated nozzle utilized by the device was analyzed under different feeding pressures, and the effects of frother concentration, feeding pressure, suction capacity, and height of sampling location on the bubble size distribution (BSD) were investigated using a high-speed video system. It was found that a large amount of air was sucked into the flotation cell by the self-aspirated nozzle arranged in a non-submerged manner, which met the requirements of flotation in terms of the suction amount of air. The suction capacity showed a positive linear correlation with negative pressure inside the nozzle. When the Methyl isobutyl carbinol (MIBC) concentration reached the critical coalescence concentration (CCC), the bubble size stabilized at approximately 0.31 mm, which was smaller than the bubble size produced by the conventional flotation machine. This indicated that bubbles suitable for flotation were generated. D 32 linearly decreased with increasing of feeding pressures and conversely increased with increasing suction capacities and sampling location heights, independent of the frother concentration. sized bubbles [10]. A Venturi type bubble generator can produce a large number of micro bubbles [13] and the Jameson cell has a low energy consumption [14]. It has been found that a rotational flow in the cyclonic-static micro-bubble flotation column is a benefit for the particles colliding with and attaching to the bubbles, and the probability of particle attachment substantially increased [15]. A non-uniform filling method was proposed to optimize the flow field. Filling with a non-uniform sieve in the cyclonic-static micro-bubble flotation column was proved to be more effective on bubble size distribution equalization [16]. In addition, it was found that rotational flow improves the effect of mineralization and increases the recovery of coarse coal particles in the cyclonic-static micro-bubble flotation column [17]. Moreover, a nozzle equipped with a long throat and arranged in a submerged manner was studied [18]. It was observed that the suction capacity of the nozzle increased with the nozzle distance and cross-section ratio. Furthermore, it resulted in a high jet kinetic energy dissipation rate. However, when exposed to air, either the suction capacity decreased significantly, or the nozzle failed to work properly.As we all know, the processes of collision, detachment, and attachment between the bubbles and the coal particles complete the final coal slime flotation process [19]. The bubble is the main carrier of the flotation process. The bubble size distribution has a significant influence on the selectivity of the bubble and the ability to carry the target mineral [20]. Bubbles of different sizes have different abilities to sepa...

A jet-stirring coupling flotation device (JSCFD) was proposed to analyze the distribution characteristics of gas holdup and bubble Sauter mean diameter (D 32 ) in a gas−liquid system under various parameters. Results of studies suggested that the gas holdup increased with methyl isobutyl carbinol concentration, feeding pressure, and gas flow rate. The maximal gas holdup in the absence of the stirring impeller was ∼23.29% for the bubble size of 0.59 mm, which was considerably lower than the maximum gas holdup of 66.27% for the bubble size of 0.31 mm in the presence of the stirring impeller; the gas holdup was raised by ∼43% due to the bubbles torn by the stirring impeller to generate extensive smaller size bubbles and increase the content of small bubbles, and increasing the stirring impeller speed was conducive to reduce the bubble size and increase the gas holdup in JSCFD. Compared to traditional flotation machines, the size of bubbles generated by JSCFD was smaller, and the gas holdup distribution conforms to the following order: JSCFD > mechanical flotation machine > column flotation, which demonstrated that the JSCFD had a noticeable effect on increasing the gas holdup and reducing the bubble size.