A New Mechanistic Model for Mineral Crystallization and Inhibition Kinetics and Its Application to Celestite

Scale inhibitors are frequently used to control the mineral scale formations during industrial processes. However, few kinetic models with a mechanistic understanding of the inhibition mechanism have been developed. In this study, a new mechanistic model is developed to predict the kinetics of the mineral scale crystallization with and without inhibitors. In this new model, it is proposed that the inhibitors can adsorb on the nucleus surfaces following a Langmuir type isotherm and increase the nucleus interfacial energy, resulting in the prolongation of the induction time. The new model is applied to predict the crystallization and inhibition kinetics of celestite, which has been observed more frequently during various industrial processes with few quantitative models developed. The predicted induction times show close agreement with the experimental data produced in this study. Moreover, the fitted Langmuir-type adsorption reaction constant KL, between celestite and the three inhibitors is comparable with the reported K-L, values in the previous studies, implying the reliability of the proposed inhibition mechanism of this new model. This new mechanistic model could be widely adopted in various disciplines, such as elucidation of the inhibition mechanisms, predicting the minimum inhibitor concentration, or new scale inhibitors design guidance, to mention a few.