Effect of the physicochemical characteristics of the disperse phase of slightly soluble compounds of nonferrous metals on the efficiency of their electroflotation extraction from aqueous solutions

The introduction of CO (3) (2-) , PO (4) (3-) and S2- ions as precipitants in solutions containing nonferrous ions led to a decrease of the average values of the hydrodynamic diameter of disperse phase particles d (av) by a factor of 1.5-2 relative to those in solutions containing the OH- precipitant. The electrokinetic zeta potential of the particles shifted toward higher negative values, -(25-55) mV, for metal phosphates and sulfides. The introduction of flocculants in the solutions led to enlargement of particles by a factor of 1.5-3 depending on the type of flocculant and the nature of the disperse phase. In the absence of flocculants, particles with sizes of 30-70 mu m and a charge of up to -15 mV were extracted most effectively. Particles with a high negative charge of the surface were not liable to effective coagulation; this negatively affected the electroflotation extraction. In this case, the use of a cationic type flocculant was most effective. In the presence of a flocculant of this type, the zeta potential shifted toward higher positive values, increasing the efficiency of electroflotation by a factor of 1.5-2; the degree of extraction of the disperse phase alpha reached 98%.