Investigation of ultra-fine grinding of agglomerated basalt dust

This paper presents preliminary results of experimental research on ultra-fine grinding of agglomerated basalt dust using a laboratory vibratory mill. The main objective was to maximize the fraction of particles smaller than 10 µm. A series of tests were performed using various combinations of grinding media (12.0 mm, 17.5 mm, and a 50/50 mix), different grinding durations, and grinding additives. The effects of ultrasonic disintegration during particle size analysis were also investigated to assess agglomeration. The most favorable outcome was achieved with a mixed set of grinding balls (Ø12.0 mm and Ø17.5 mm) combined with 0.4% propylene glycol. This configuration led to a significant increase in the sub-10 µm fraction from 25.4% in the feed material up to 70.5% after 60 minutes of grinding. Despite the challenges associated with the high initial moisture content of the raw material and the tendency for particle agglomeration during dry grinding, the results demonstrate the high potential of vibratory mills for the efficient production of fine basalt powder suitable for environmental and agricultural applications.