Dissolution Reaction Rate Research Articles

Kinetic study of dissolution of asbestos fibers in water

Kinetics of dissolution of asbestos minerals in water were studied over a temperature range of 5 to 45°C. A parallelism was noted between the rate of dissolution of magnesium from magnesium silicates and the rate of pH drift. The rate of dissolution reaction was directly proportional to the specific surface area of the asbestos minerals. Both magnesium ion and hydroxyl ion concentrations were temperature-sensitive only in the initial stage of the contact between chrysotile mineral and water. The mechanism of dissolution of dissolved species from chrysotile was discussed in terms of the energy of activation. The activation enthalpies were calculated to be 5.5 and 6.5 kcal/mol for dissolution of magnesium and increasing of hydroxyl ion concentration, respectively. These results indicate that the rate controlling mechanism for both magnesium and hydroxyl ion dissolution is diffusion from the surface into water.