Abstract
Particle size of CaCO3 obtained from Ca (OH) 2 as a starting material, depends on the particle size distribution and specific surface area of the hydroxide.
In order to evaluate the particle characteristics of mother substance, Ca (OH) 2, reactivities with a strongly acidic ion exchangeresin (H-R) and with an oxalic acid solution were studied with comparing each other.
The results obtained are summerized as follows;
1) Change in electrical condition (κ) during dropwise addition of H-R to a Ca (OH) 2 suspension depends on Ca (OH) 2 particle size. Especially, a gradual change in K at an initial addition of H-R is related apparently to the dissolution rate of Ca (OH) 2 particle.
2) Addition of oxalic acid which is less equivalent to Ca (OH) 2 results in pH recovery owing to the dissolution of residual Ca (OH) 2 particle.
The time needed to the pH recovery is also related to the particle size of Ca (OH) 2.
3) There is significant relationship between CaCO3 and its raw material, Ca (OH) 2 in particle size.
