This document is the final report of work on a project concerned with the fragmentation of char particles during pulverized coal combustion that was conducted at the High Temperature Gasdynamics Laboratory at Stanford University, Stanford, California. The project is intended to satisfy, in part, PETC`s research efforts to understand the chemical and physical processes that govern coal combustion. The overall objectives of the project were: (1) to characterize the fragmentation events as a function of combustion environment, (2) to characterize fragmentation with respect to particle porosity and mineral loadings, (3) to assess overall mass loss rates with respect to particle fragmentation, and (4) to quantify the impact of fragmentation on unburned carbon in ash. The knowledge obtained during the course of this project can be used to predict accurately the overall mass loss rates of coals based on both the physical and chemical characteristics of their chars. The work provides a means of assessing reasons for unburned carbon in the ash of coal fired boilers and furnaces.