Investigation into the froth flotation and selection of reagents on the basis of the mechanism of their action: Report 2. A comparison of flotation properties of millimeter,micrometer, and nanometer bubbles based on equations of capillary physics part one

Calculations with the application of equations of capillary physics (ECP) showed that the capillary pressure in the bubbles with a diameter from 3 mm to 5 nm varies from several thousandths to several hundreds of atmospheres and affects the processes associated with froth flotation. It is shown that bubbles 2 μm in diameter can spontaneously (i.e., with a decrease in energy) adhere to a solid surface, and this tendency increases in an antibate manner as their size decreases, which is the main factor. The reality of such a mechanism is confirmed by the multiyear practice of applying the Potter-Delprat process. In connection with the aforesaid, when investigating the flotation process, it is more rational not to orient for the principle of “effective collisions” of particles and bubbles as a necessary condition for their adherence and flotation, but to apply the ECP. This approach is more productive.     

Investigation into the froth flotation and selection of reagents on the basis of the mechanism of their action report 2. A comparison of flotation properties of millimeter,micrometer, and nanometer bubbles based on equations of capillary physics (Part Two)

The influence of the capillary pressure P _ca of gas in microbubbles on bubble spread over a substrate (particle) after adhesion is considered (for bubbles ranging in size from 2 mm to 20 nm). The dimensionless parameter K _a characterizes the microbubble spread with decrease in the bubble form factor β by no more than 0.000001 of its initial value. There is a clear symbatic relation between P _ca and K _a. The microbubble begins to spread when it measures 200 μm; its motion increases markedly as it becomes smaller. With decrease in bubble size, the rock and slurry particles adhering to its surface are removed. Of course, this enhances the foam quality.