Measurement and scale‐up of secondary nucleation kinetics for the potash alum‐water system

Secondary nucleation kinetics for potash alum in draft‐tube baffled crystallizers have been determined from steady state crystal size distributions measured down to about 5 μm. Differences in nucleation rates were found for crystallizers of similar geometry but different capacity. Models relating the frequency of crystal/propeller collisions to crystallizer geometry and operating parameters were compared. In general, these successfully accounted for the observed differences in nucleation rates.