Fluid particle group reaction model and experimental verification

Based on a shrinking core model (SCM) that takes into account the particle size distribution (PSD) and product characteristics, a model is established to simulate the reaction process of the fluid particle group. In this model, a total reaction rate coefficient k_m is defined to describe the reaction behavior. Simulation results show that the particle group conversion is determined by k_m, the PSD pattern, and reaction condition. The dissolution characteristics of five kinds of limestone from different places in China are studied by using the pH-stat method in a stirred tank at different temperatures (30-60 °C), pH values (4.6-6.2) and PSD. By choosing proper k_m, the model can well describe the limestone dissolution process in acid with different reaction conditions. For different reaction conditions, the average total reaction coefficient can be obtained via iteration. Moreover, k_m can be deduced numerically at a given reaction time, which we propose a new way of obtaining the reaction parameter from experiment.