Role of Water Chemistry on Balling

Abstract

Green ball qualities are adversely affected by increased concentrations of ca++ and Mg++ in process waters because of the replacement of Na+ in bentonite by the divalent cations through cation exchange reaction. Several approaches were considered and some of the approaches were tested for remedying the adverse effects, namely, displacing moisture water by softened water by washing in filtration, increased use of bentonite, and such additives as Na2C03, NaHC03, NaOH, (NH4)2C03, EDTA, modified starch, and molasses. The use of NaOH and Na2C03 were quite effective in restoring the ball quality, particularly, when a combination of a modified starch and Na OH was used. It becomes of interest to investigate the mechanism that leads to the beneficial effects of these additives, so that some other additives, besides Na+containing salts, may be suggested.