Bubble mineralization form

Mineralization floating mineral slurry bubble is a bubble group behavior between the group and the group of mineral particles, different from the case of a single mineral particles and air bubbles than half a century, a large number of scholars and determination by high-speed photography, modern flotation The phenomenon of bubble mineralization in the tank is summarized into three forms, as shown in Figure 4-6-33.

1 The ore particles adhere to the bubbles formed by collision and agitation to form mineralized bubbles. When the bubbles move, the adhered ore clusters tend to gather at the tail of the bubble, forming a so-called mineralized tail shell, as shown in the figure (a ). The percentage of the total surface area occupied by the mineralized tail shell varies with the flotation conditions, and can be as high as 20% to 30% in the selection of more floatable particles, and only 1% to 2% lower.

2 Air is supersaturated in water on the hydrophobic surface of the particles, grows and merges, and precipitates a microbubble complex, as shown in (c). At this time, many bubbles adhere to a mineral particle, and this mineralized form is important for particle flotation.

3 The floc is composed of a plurality of microbubbles and a plurality of fine particles, as shown in (c) of the drawing, the prerequisite is to form a hydrophobic floc which tends to float out of the floc.

The form of bubble mineralization is related to the type of flotation machine and the mode of inflation. Commonly used flotation machines are mechanically agitated, which is a positive pressure aeration. Bubble mineralization is basically the first type, but there is a negative pressure zone around the impeller, and some microbubbles can be precipitated, that is, the second form. In the reduced-pressure flotation machine, mainly air dissolved in the slurry is precipitated on the surface of the hydrophobic ore particles to form microbubbles.

Therefore, in the second form, it is also possible to adhere to each other to form a floc. In the jet and cyclone flotation machine, the pressure drop at the nozzle is similar to the vacuum flotation, so the bubble mineralization is dominated by the second and third forms. In fact, as long as there are fine particles in the material and bubbles with smaller diameters, there is a third form. Usually, these three forms of mineralized bubbles coexist during the flotation process, but the proportions are different. Although it is theoretically recognized that the second form has the highest selectivity and ability to capture, in practice it is dominated by the first form.