What problems should be paid attention to when determining the speed of the flotation machine
Issuing time:2021-01-23 13:38
During the flotation process of the flotation machine, there must be sufficient stirring strength in the flotation tank to fully suspend the ore slurry and fully contact the ore particles with bubbles to increase the collision probability between the ore particles and the bubbles. It should not be too strong to cause "turning over" on the pulp surface. If the phenomenon of "turning over" appears on the pulp surface, the sorting environment will be destroyed, and it must be dealt with in time. Therefore, when we operate, we must consider three aspects when determining the speed of the flotation machine.
First: Note that the stirring speed should be greater than the critical speed required for the suspension of solid particles. Under the conditions of the flotation process, the value of the above formula should be as large as possible to meet the requirements of industrial production. The equivalent diameter of large particles in the slurry is taken as d, which is 1mm, the ore density is generally less than 4×l03kg/m3, then (pp-p) can be 3×l03kg/m3; the solid-liquid mass ratio is generally between 20%-40%. X is 40; the kinematic viscosity of water v=10^-6m2/s; the k value is 150; for the new flotation machine, the impeller diameter d=0.06m. Therefore, to make the particles reach a completely suspended state, the speed of the flotation machine must be greater than 764.92 rpm.
Second: The stirring speed should be greater than the speed required for the dispersed gas. Taking the standard tank as an example, the area of the flotation tank is 0.01mz. The diameter is approximately 0.1m, and the aeration volume is 300L/h1. Therefore, the rotation speed of the flotation machine must be greater than 1053.3 rpm to make the charged air fully dispersed. The stirring speed should not be too high, so as not to damage the stability of the separation zone and the foam zone.
Third: Excessive speed will increase the inertial force of the mineral particles falling off the bubbles, which is not conducive to the mineralization of the bubbles, and will also cause the rising turbulent flow velocity of the slurry to be too high, causing the slurry surface to "turn over", destroying the separation environment and affecting sorting. However, under different flotation conditions, the critical speed varies greatly for different types of flotation machines. There is no uniform formula. The choice must be based on actual experience. In practice, we have found that the flotation required for reverse flotation of bauxite The machine speed is higher than that of conventional ore flotation.