The effects of two potassium salt additives, ethylene diamine tetra acetic acid dipotassium salt (EDTA) and potassium pyrophosphate (KPY), on the crystallization of potassium dihydrogen phosphate (KDP) were investigated. The nucleation kinetic was studied by the measurements of metastable zone width and induction time. The crystal growth rate of a certain crystal face was determined from the in-line images taken with a MTS Particle Image Analysis (PIA) video microscope. Based on the obtained results, a significant promotion effect on both nucleation and growth of KDP has been observed when EDTA was used as additive. On the contrary, KPY exhibits strong inhibiting impacts. The mechanism of the EDTA promotion effect was further studied with 2-dimension nucleation model. The presence of EDTA increased the density of adsorbed crystallizing solute molecules on the surface of the crystal.
|Number of pages||6|
|Issue number||1901 II|
|Publication status||Published - 2005|
|MoE publication type||A1 Journal article-refereed|