Kinetics of the Acid Digestion of Serpentine with Concurrent Grinding. 2. Detailed Investigation and Model Development

Abstract

The rapid extraction of magnesium from serpentine is critical to novel low-pressure mineral carbonation methodology. Though almost any acid can dissolve the magnesium, the rate plays a critical role in the industrialization of the process. It has been demonstrated that including a low-energy, attrition-type grinding with the chemical attack of the acid can more than double the extraction rate. In part 1 of this investigation, it was found that a model that accounts for surface reaction, surface speciation, the electrical double layer, particle size distribution, and ash layer diffusion can adequately describe the kinetics of the dissolution of serpentine with concurrent grinding. However, the model did not account for changes in temperature, concentration, and grinding energy input. We report here the model developments and changes as well as a detailed experimental investigation to provide validation for the model.