An established implicit finite difference method was extended to predict the behaviour of particles when both diffusion and interface reaction effect the kinetics of growth or dissolution.
A quasi-steadystate model was also obtained. Mixed behaviour must be expected for a relatively large range of conditions, 0.01a
0
k/D<10,>k is a kinetic constant,a
o is the initial radius, andD is diffusivity. Evolution from initial mixed control to strictly diffusion controlled growth is possible for moderatea
0
k/D, but only when the particle size becomes much larger than the initial size.