ULTRA-FLOCCULATION OF DILUTED FINE DISPERSE SUSPENSIONS

摘要

This article studies the impact of the hydrodynamic treatment of varying intensity on the process of flocculation and the subsequent sedimentation separation of diluted (<1 g/1 solids) fine-disperse (<1 micron) suspensions. Using the reference water suspensions of alumina hydroxide, Na- montmorillonite, and nickel ferrocyanide, we have demonstrated that the application of the vigorous hydrodynamic treatment, characterized by the medium gradient velocity G=2000-4000s~(-1), followed by a later mild hydrodynamic treatment of stepwise decreasing intensity (G of 1000 to 30s~(-1)) can significantly improve the results in terms of flocculation and subsequent sedimentation separation of suspensions, specifically by: increasing the rate of the sedimentation of flocculated suspensions by more than two times; decreasing the residual concentration of solids in water by 4-10 times; decreasing the consumption of flocculants by 2-3 times; and enhancing the densification of the solid phase residue by 1.5-2 times.