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 degrees 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. (C) 2012 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.