Dissolution and Dispersion Behavior of Barium Carbonate in Aqueous Suspensions

Dissolution of BaCO₃ and its effect on the dispersion behavior of aqueous BaCO₃ suspensions at various pH values have been investigated. The amount of leached Ba²⁺ decreases with increasing pH value, which agrees with thermodynamically calculated results. The dissolution of BaCO₃ also causes an increase in pH value of the suspension, but the change decreases with increasing initial pH value. The isoelectric point (IEP) of leached BaCO₃ powder is at a pH of ～10–10.5 and remains unchanged with increasing solids loading. The IEP of BaCO₃ shows no significant change with added KCl or K₂CO₃, but shifts to a higher pH with increasing concentration of added BaCl₂.