Turbidimetric study of fluorite nucleation in solution

Area of Science:

• Materials Science
• Chemical Engineering
• Physical Chemistry

Background:

• Fluorite (calcium fluoride) precipitation is crucial in various industrial processes.
• Understanding nucleation and growth kinetics is essential for controlling particle formation.

Purpose of the Study:

• To investigate the precipitation kinetics of fluorite from solution at 30 and 37°C.
• To determine nucleation frequency, particle size, and number density over time.
• To compare experimental nucleation trends with classical nucleation theory.

Main Methods:

• Turbidity measurements at various wavelengths.
• Mie theory analysis for particle size and number density.
• Sedimentation analysis for validation.
• Supersaturation-dependent nucleation frequency analysis.

Main Results:

• Number density and average particle size were determined as functions of time.
• Nucleation frequency trends agreed well with classical nucleation theory.
• Surface energies were calculated as 102 mJ/m² at 30°C and 89 mJ/m² at 37°C.
• Observed nucleation rates were significantly lower than theoretical predictions.

Conclusions:

• Classical nucleation theory accurately describes the trend of nucleation frequency with supersaturation.
• Discrepancies in absolute nucleation rates suggest an overestimation of postcritical nuclei growth rates in current theories.
• The study provides valuable insights into fluorite precipitation mechanisms and offers parameters for process optimization.