The effect of mechanical activation in the production of olivine surface area

• Combining dry and wet milling of olivine can yield very high surface areas (SSA).
• The SSA production rates exceed those that can be obtained by wet milling alone.
• The products combine a high SSA with mechanically activated surfaces.

This study investigates the effect of dry mechanical activation of olivine as a pre-treatment step prior to wet milling with respect to the production of specific surface area. Milling experiments combining the two milling modes (i.e. dry and wet) were performed using a laboratory planetary mill. The specific surface area of the milled products was determined by N2-adsorption (BET), whereas their crystallinity was studied using X-ray diffraction (XRD). Combining dry mechanical activation with subsequent wet milling makes it possible to produce specific surface area at rates that exceed those that can be obtained by wet milling alone. Whereas a value of 26.28 ± 1.28 m2/g was obtained after 30 min of wet milling, 25 min of dry mechanical activation followed by 5 min of wet milling resulted in a specific surface area of 64.44 ± 2.13 m2/g. The concept could represent significant energy savings, and enable olivine products that combine high specific surface area with an activated structurally disordered surface.