Energy‐based evaluation of a mechanically activated kaolinite‐rich clay

Abstract

This study addresses Mechano‐chemical activation (MCA) of clays; specifically, a kaolinite‐rich clay was activated in a planetary ball mill at 500 rpm with ball‐to‐powder ratios of 10 and 20 for 5–40 min. A kinematic model helps translate milling conditions into milling energy, enabling the evaluation of the relationship between energy input and structural disorder, and R ³ reactivity. XRD, TGA, and FTIR indicate progressive amorphization and increased reactivity with milling energy up to a limit where the crystalline order loss of the activate clay alone does not govern dissolution. Hence, the relationship between R ³ reactivity and energy input, R ³ = f(e) , can be fitted using an exponential saturation function with an upper reactivity asymptote, featuring a decay in clay activation rate ( dR ³ /de ) at higher energies. Altogether, the study links clay milling conditions, structural evolution, and reactivity; highlighting the limitations of XRD amorphous content as a proxy for reactivity and providing a basis for optimisation of mechano‐chemically activation of clays.