Grinding of calcite suspensions in a stirred media mill: Effect of operational parameters on the product quality and the specific energy

• The time needed to get nanoparticles decreases increasing the stirrer speed.
• For a given fineness, a lower specific energy is needed using a low stirrer speed.
• Solid concentration affects grinding kinetics but improves energy efficiency.
• Viscosity is a key parameter to control size reduction in a nanogrinding process.

This paper investigates the production of calcite suspensions by a wet grinding process in a stirred media mill. The experimental set-up allows the circulation mode process in the presence of sodium polyacrylate as additive. The influence of different operational parameters on grinding results in terms of particle size distribution and rheological behavior of the suspensions as well as the grinding efficiency is presented. We observe that the specific energy input that leads to a required product quality is not the same. Moreover, analyzing the trend of particle size versus the specific energy input instead of versus the grinding time, different and opposite conclusions flow from the experiment results. In addition, the effect of particle mean size on the suspension viscosity is presented.

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