In-line image analysis on the effects of additives in batch cooling crystallization

Haiyan Qu, Marjatta Louhi-Kultanen*, Juha Kallas

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

50 Citations (Scopus)


The effects of two potassium salt additives, ethylene diamine tetra acetic acid dipotassium salt (EDTA) and potassium pyrophosphate (KPY), on the batch cooling crystallization of potassium dihydrogen phosphate (KDP) were investigated. The crystal growth rates of certain crystal faces were determined from in-line images taken with a MTS particle image analysis (PIA) video microscope. An in-line image processing method was developed to characterize the size and shape of the crystals. The nucleation kinetics was studied by measurement of the metastable zone width and induction time. A significant promotion effect on both nucleation and growth of KDP was observed when EDTA was used as an additive. KPY, however, exhibited strong inhibiting impacts. The mechanism underlying the EDTA promotion effect on crystal growth was further studied with the 2-dimension nucleation model. It is shown that the presence of EDTA increased the density of adsorbed molecules of the crystallizing solute on the surface of the crystal.

Original languageEnglish
Pages (from-to)286-294
Number of pages9
JournalJournal of Crystal Growth
Issue number1
Publication statusPublished - 15 Mar 2006
MoE publication typeA1 Journal article-refereed


  • A1. Impurities
  • A2. Growth from solution
  • B1. Potassium compounds
  • B3. In-line image analysis

Fingerprint Dive into the research topics of 'In-line image analysis on the effects of additives in batch cooling crystallization'. Together they form a unique fingerprint.

Cite this