In the present work the agglomeration of a natural organic solid in a top-spray fluidized bed at bench scale was studied by means of statistical analysis and modeling using a discretized population balance. These engineering approaches were coupled to elucidate the influence of elutriated fines recirculation and its interaction with bed temperature and atomizing binder time on agglomeration mechanisms of solids presenting initial particle diameter polydispersity. First, a 2(3) factorial design was considered, accounting for the factors of atomizing binder time and bed temperature with and without consideration of the recirculation of elutriated fines into the fluidized chamber. Second, the agglomerate observations were analyzed by a variance analysis, with a significance level of 5%, using the mean particle diameter as response variable. Finally, the observations were predicted through a discretized population balance accounting for nucleation, agglomeration, and growth kinetics. The results indicated that bed temperature and atomizing binder time, together with the interaction between bed temperature and the recirculation of elutriated fines, were factors affecting agglomeration mechanisms. Nucleation and aggregation mechanisms were dominant when the lowest bed temperature and the longest atomizing binder time under fines recirculation conditions were used.