Crystal growth and dissolution rates of potassium pentaborate octahydrate

In the present work, the growth and dissolution rates of potassium pentaborate octahydrate (K₂B₁₀O_16.8H ₂O) were investigated in a fluidized bed crystallizer under well established conditions of supersaturation and fluidization. The seed size fractions of-1000 + 850 μm, -600 +500 μm, and -425 + 355 μm were used to determine the effect of initial crystal size on the growth rates. It was found that the overall growth rate of potassium pentaborate octahydrate changes linearly with supersaturation and does not depend on the initial size of seeds. The evaluation of growth rates in terms of isothermal effectiveness factors indicates an equal contribution of the mass transfer and the integration steps to the crystal growth of potassium pentaborate octahydrate.