The development of continuous crystallizer and observation of formation and growth of calcium oxalate crystals

A continuous flow crystallizer system of calcium oxalate has been developed. Crystal nucleation rate (B0) and growth rate (G) were calculated by the formula by Randolph and Larson. Nucleation rate, growth rate and crystal mass concentration were decreased with increase of residence time. A linear relationship was observed between growth rate and nucleation rate (B0 = 1.58 x 10(4)G0.924, r = 0.981). Crystals formed in the solution were composed of calcium oxalate dihydrate by infrared spectroscopic analysis. Growth rate and crystal mass did not change between pH 5.0 and 6.5 but increased above pH 7.0. CG-120 and sodium pentosan polysulfate inhibited the nucleation rate, crystal mass concentration but did not influence the growth rate of the crystals