The dissolution times of spherical particles

Abstract

The differential equation governing the rate of change of radius of a spherical particle dissolving or growing in a fluid has been numerically integrated by computer. The particle radius, as a function of time, can thus be calculated, and the dependence of the overall particle lifetime upon physical parameters obtained. The effects of high mass flux, change of solubility with particle size, and progressive saturation due to dissolution into a finite volume of liquid can all be taken into account during the integration process. Results are presented for salicylic, boric and citric acids dissolving in and crystallizing from water; these represent the behaviour of sparingly soluble, moderately soluble and very soluble compounds respectively.