In our previous work, we observed that a thermal shock process could fragment zeolite particles to approximately one-fourth of the initial size. Here, we further investigate this finding by applying repeated thermal shocks to the zeolite particles and observed the effect on the resulting particle size. We determined that repeated thermal shocks progressively reduce the zeolite particle size, though the resultant size was not always one-fourth of the previous size. We claim that the thermal shock generated a high-temperature gradient, and the zeolite structure converted into a quartz structure at the point at which the temperature gradient reached a maximum, resulting in a silicon-rich surface of the produced particles (higher Si/Al ratio). We also developed a model to predict the possible existence of a critical radius, below which the size will not be reduced by thermal shock. The critical radius decreases when the shock temperature increases. The prediction is qualitatively consistent with the observed final particle size after applying different shock temperatures. (C) 2017 Elsevier B.V. All rights reserved.