Introduction of Particle‐Size Distribution into Kinetics of Solid‐State Reaction

A theory to introduce particle‐size distribution of the reacting component into Carter's equation on solid‐state reaction is described. The particle‐size distribution is defined as follows: The reacting component is divided according to particle size into groups and the mean particle sizes of each group are set in a geometrical series. By introducing the particle size distribution into the equation, the reacted fractions of the groups can be mathematically determined. The theory was applied to the solid‐state reaction of lead zircon‐ate from lead oxide and zirconium oxide having a particle size distribution. Using the measured particle‐size distribution of the zirconium oxide and the overall fraction of zirconium oxide reacted, an activation energy of about 100 kcal per mole was determined.