The mechanism of surface chemical kinetics of dissolution of minerals

Abstract

This paper deals with the mechanism of dissolution reaction kinetics of minerals in aqueous solution based on the theory of surface chemistry. Surface chemical catalysis would lead to an obvious decrease in active energy of dissolution reaction of minerals. The dissolution rate of minerals is controlled by surface adsorption, surface exchange reaction and desorption, depending on pH of the solution and is directly proportional to\(a_{H^ + }^{n_\theta } \). When controlled by surface adsorption, i.e.,n θ= 1, the dissolution rate will decrease with increasing pH; when controlled by surface exchange reaction, i. e.,n θ= 0, the dissolution rate is independent of pH; when controlled by desorption,n θ is a positive decimal between 0 and 1 in acidic solution and a negative decimal between −1 and 0 in alkaline solution. Dissolution of many minerals is controlled by surface adsorption and/or surface exchange reactions under acid conditions and by desorption under alkaline conditions.