Dontsova T. Separation of fine disperse sorbents from water solution through ultra-flocculation and microflotation

The thesis studies colloid-hydrodynamic relationships within the process of separation of fine disperse sorbents based on clay minerals, alumina hydroxide and copper ferrocyanides and nickel from water solutions that are purified with application of said sorbents with the help of ultra-flocculation, sedimentation and turbulent microflotation techniques. It has been found that the decrease of sorbent particles from 1 mm to 1 µm results into shortening of sorption treatment time (from 1-2 hour to 30 s), and sorbent consumption and therefore, amount of generated wastes decreases by 8-10 times. There has also been proposed the experimental methodology for determining of coupling energy of particles in flocs which is based on measuring dependence of maximum dimensions of flocs on the amount of dissipated mechanical energy. It has been shown that the maximum efficiency of floccular process is in correspondence with the maximum of the coupling energy of particles, which, in its turn, depend on its nature, type and quantity of the flocculent. We have also defined the optimal hydrodynamic treatment mode of the suspension in the process of flocculation, which involves vigorous hydrodynamic treatment (average medium velocity gradient - G = 1200-3000 s-1) and subsequent mild hydrodynamic treatment decreasing in intensity in a stepped mode (the value of G decreases from от 1000 до 30 s-1). We have shown that due to application of this treatment the rate of separation of flocculated fine disperses sorbents from water by sedimentation increases by 25-50 %, and specific volume of watered sediment decreases by 2 times. We have proposed the efficient method for separating fine disperse sorbents from water solution, which are purified with the help of these sorbents, which comprises the series of ultra-flocculation, sedimentation and turbulent microflotation steps.