How mechanically agitated flotation machine air bubbles are generated

      One of the main functions of flotation machine equipment is to fill the slurry with air, disperse into a large number of small bubbles, and then collide with the mineral particles to form mineralized bubbles. Therefore, flotation slurry aeration is the premise of flotation and is the main factor that determines the flotation machine effect. The inflating of flotation slurry mainly includes two processes: the generation of bubbles and the merger and dissolution of bubbles. Puyang Mineral Machinery introduces you to how the mechanical stirring flotation machine bubble is generated.

 

      The mechanical agitation flotation machine generates air bubbles mainly by mechanical agitation to generate air bubbles. At this point, the rotor or impeller with different shapes stirs the pulp vigorously, causing the slurry to produce a strong catastrophic movement. Due to the shear effect of the vortex, the air sucked into the flotation machine is dispersed into bubbles of unequal diameter. The greater the relative velocity of the slurry and the bubble, the higher the turbulence, the lower the interfacial tension of the gas-liquid interface, and the smaller the diameter of the gas bubbles divided by the vortex shear of the slurry, the larger the number. However, the stirring is too strong, the energy consumption is large, the liquid surface is unstable, and the bubble diameter is too small, which is also unfavorable for the floating of the ore grains.

 

         The key components of a mechanically agitated flotation machine are the rotor and the stator. The rotor is the impeller, and its working parts may be in the shape of a water pump impeller - a turbine, a horizontal disk with upright blades, a hybrid impeller, etc. It may also be a rod or a radial plate arranged in a hammer-like arrangement. When the rotor rotates, cavities form behind the blades and suck in air. The slurry that bypasses the blade forms two rows of swirling vortices (Karman vortexes), and the air is sucked by these scourges into the vortex to form bubbles. The formation of bubbles in the experiment shows that the ability of the rotor to disperse air is limited, and the ability of the impeller to self-prime the flotation machine to inhale air depends on the dispersing ability of the rotor and will not exceed this limit. Increasing the number of blades or increasing the speed of the blades can increase the amount of aeration, but the power consumption and wear will increase, and the liquid level may also be unstable, which is unfavorable for coarse grain sorting.