EFFECT OF HARDWATER ON SELECTIVE FLOCCULATION OF DIASPORIC-BAUXITE

摘要

In this study, selective flocculating of diasporic-bauxite using anion macromolecular reagent as flocculant was tested to separate diaspore from alum-silicate minerals in hard water system. Firstly, hard water greatly affects the flocculating process due to the Ca2+ and Mg~(2+) in it. Same addition dosage of dispersant as in soft water can’t fully desperate the particles. Although particles fully were disperated by greatly addition of dispersants, the flocculating processes performed unselectively. Secondly, certain softening agent can eliminated or weaken the negative effect of hard water on flocculating processes. Self-made softening agent performed well in these tests, since the A/S and recovery of concentrate were appreciating. Finally, via dynamics simulation, the elimination of negative effects was observed. Softening agent molecules restricted the Ca2+, so eliminated the effects of Ca2+. Furthermore, since one molecule only restricted one Ca2+, it wouldn’t make the Ca2+ settle, there were no deposit particles to disturb the flocculation of diaspore particles. And so was the Mg~(2+).