Impurity distribution in a solid-liquid interface during static layer crystallization

Area of Science:

• Materials Science
• Chemical Engineering
• Physical Chemistry

Background:

• Static layer crystallization is crucial for purifying materials.
• Understanding impurity distribution is key to optimizing crystallization processes.
• Previous models often simplified the complex interplay of growth and diffusion.

Purpose of the Study:

• To theoretically and experimentally investigate impurity distribution in static layer crystallization.
• To develop and validate a mathematical model for impurity segregation.
• To analyze the influence of key parameters on impurity profiles.

Main Methods:

• Development of a coupled mass and energy balance model.
• Numerical solution of the mathematical model.
• Experimental crystallization of a caprolactam-water eutectic mixture.
• Comparison of model predictions with experimental impurity profiles.

Main Results:

• The model accurately predicts impurity distribution within crystalline layers.
• Key factors influencing impurity segregation include interfacial distribution coefficient and layer thickness.
• Concentration and temperature at the solid-liquid interface significantly impact impurity profiles.
• Model predictions were validated against experimental data.

Conclusions:

• The developed model provides a robust framework for understanding impurity behavior during static layer crystallization.
• The findings enhance the predictive capability for optimizing purification processes.
• This research contributes to the fundamental understanding of crystallization phenomena.