Distribution of metallic ions in a single KDP crystal grown from aqueous solution

Abstract

A single KDP (potassium dihydrogen phosphate) crystal was grown in a supersaturated solution containing a metallic ion (Al 3+ , Fe 3+, or Cr 3+ ). The growth rate, morphology, and distribution of the metallic ions into the KDP crystal were measured as the ionic concentration and supersaturation in the solution changed. It was found that in the KDP crystal, Al 3+ and Fe 3+ were greatly concentrated, but Cr 3+ was diluted. Complete expressions for the effect of metallic ions on all aspects of the growth of KDP crystal were suggested. The growth rates of (100) and (101) faces were well correlated by the empirical equation and resulted in good estimation of morphology. The distribution of metallic ions into KDP crystal was also correlated by the distribution model.

Multi-Impurity Adsorption Model for Modeling Crystal Purity and Shape Evolution during Crystallization Processes in Impure Media

“…The non-estimated kinetic parameters, which are used in the model were previously determined by Gunawan et al 26 , , Kubota et al 47 , and Maeda et al 70 . (23) [ ] …”

“…The χ c, j is the mole fraction of the j th CGM in the crystal phase, which can be written as the mole fraction of the j th CGM in the solution multiplied by its interfacial distribution coefficient, K d, i , j . Thus, the mole fraction can be given by The c CGM, j and c are the concentrations of the j th CGM and solute, M j and M c are the molar weights of the j th CGM and the solute, while the distribution coefficient K d, i , j is In this equation, K d, i , j is thermodynamic distribution coefficient of the j th CGM, the k m, j and k min ,j are the mass transfer coefficients with crystal growth at the actual growth rate and at the G min ,i which is the specific growth rate when impurity distribution does not occur, where k m0, j is mass transfer coefficients without crystal growth.…”

“…Finally, the parameters of the effect of CGM2 impurity on the growth kinetics are obtained by fitting the model to Exp2. The nonestimated kinetic parameters, which are used in the model were previously determined by Gunawan et al, Kubota et al, and Maeda et al Parameter estimation was carried out in Matlab based on a standard nonlinear least-square method. The estimation problem is defined as where y l and ỹ l are measured and calculated values of the mean aspect ratio in the l th sampling point in time.…”

Adsorption based competitive purity control in crystallization

“…The j c, determines the mole fraction of the th j CGM in the crystal phase (Maeda et al, 2006;Borsos et al, 2014). The general form of the moment equation system is written as the follows It is well known that the first moment is related to the particle number, while the third cross-moment is proportional to the particle volume.…”

Effect of La3+ ions on the habit of KDP crystals

“…Selective additives have been applied vastly in crystal growth industry in order to change the appearance shape of crystals and modify their qualities [1]. Study of influence of impurities on the crystal growth procedure has been the subject of many researches in recent years [2][3][4][5][6][7].…”