Theory And Application Study On The Effect Of Pulp Turbulence Degree In Flotation Cell On Flotation

At the beginning stage of industrial partial flow test of low intensive magnetic separation-high intensive magnetic separation-flotation separation in the flotation plant of Baotou Iron and Steel Complex, the phenomenon of big and empty bubble was observed during the cleaning process of reverse flotation to remove fluorine from Iron concentrate of magnetic separation, similar phenomenon was observed when treating oxide ores such as bauxite and phosphate, the only difference is that the former is much more serious. It is a common phenomenon in industrial flotation, but it is caused little notice. This paper studied the reverse flotation process of fluorine removal from Iron concentrate of magnetic separation of Baotou Iron and Steel Complex and flotation process of Henan ZhongZhou bauxite ore. some relevant flotation questions have been systematically researched.l.The effect of the diameter of particles, aeration, the diameter of bubble and reagents on flotation have been studied with fluorine and hematite pure minerals in hallimond tube .It demonstrated that the recovery of fluorine increased with the increasing of the diameter of particles, aeration ,degree of agitation and with the decreasing of the diameter of bubble. Fluorine can float at a very low degree of agitation. Fluorine belongs to the minerals which can be easily floated. At the condition of pH equals 9,sodium silicate is used as depressant, NaOl is used as collector, Fluorine and hematite can be separated easily. According the photograph of fluorine froth, we can see that fluorine attaches on the bottom of the bubbles in the form of multiple particles.2.PDA(particle dynamics analyzer system) was used to measure the flow velocity of particles in the XFD-12 flotation cell, the results show that tangential mean velocity in the radial direction changes from positive to negative in the flotation cell, naught point emerge in the medium of the radial direction ,it is where backward fluid emerge ,shear stress of backward fluid induce the particle detachment from bubbles .Axial mean velocity of mixing region raised in the radial direction, that favors the suspension of particles near the cell. Axial mean velocities of flotation region increased at first and then decreased, power of suspension decrease in the radial direction. Axial relative velocities of flotation region and froth region decreased in the radial direction, the power of detachment decreased while the axial relative velocity decreased in the radial direction. The power of suspension of the non-mineralized particles and the detachment of mineralized particles increased while increasing impeller speed or turbulence degree.3. After balance forces of particles at the fluid interface were analyzed, we calculated the maximal diameter of flotation fluorine particle in the cleaning test of high magnetite concentrate of fluorite removal by reverse flotation. When impeller Reynolds increase from 0.16 Xl06 to 0.7 X 106 , the maximal diameter of flotation fluorine particle decrease from 0.134mm to 0.059mm.The results of sieve analysis show that while impeller Reynolds increase from 0.32 X 106 to 0.7 X 106 ,+0.()74mm range sieve fraction is quite limited,+0.054mm range sieve fraction decline from 9.25% to 4.58% andDoctoral dissertation ABSTRACT-0.054+0.038mm range sieve fraction decline froml3.68% to 8.3%.The results of calculating and sieve analysis show that coarse range sieve fraction of the cleaner decline while degree of turbulence increasing.4.The measured flow velocities by means of PDA in the XFD-12 flotation cell were used to calculate turbulence energy spectrum of mixing region, flotation region and froth region. The results have shown that turbulence frequency is less than 20HZ in the mixing region, in the flotation region between 20-30HZ, in the froth region between 25-35HZ. Turbulence energy in the mixing region is bigger that in the flotation region and bigger that in the froth regi...