Correlation of the surface roughness of some industrial minerals with their wettability parameters

Insight into the Influence of Surface Roughness on the Wettability of Apatite and Dolomite

“…This suggested that the difference of wettability between apatite and dolomite could be enlarged by adjusting the surface roughness of them, and then the difference of floatability between them was expected to enlarge to strengthen the flotation separation. Previous studies [7,[9][10][11]26,46,47] had also proven that this insight was feasible, in which the size and shape of mineral particles could be changed by controlling grinding, thus affecting their surface roughness. Grinding the malachite with quartz can improve the surface roughness of malachite particles, and then improve its floatability [22].…”

“…It has been shown that the surface roughness has an effect on the surface wettability or flotation performance of quartz [7,19,20], barite [21], malachite [22], glass beads [8], complex sulfide ores [23,24], coal [25] and so on. Calcite, barite, and quartz particles with different surface roughness were obtained by using a pulverizer, ball mill, and autogenous mill, and the contact angle measurements showed that the particles with the rougher surface had higher wettability [26]. Grinding with different mills also showed that the increase of roundness and roughness of particles due to grinding reduced the hydrophobicity or floatability of talc minerals [11].…”

“…In some cases, the results were even inconsistent. However, the influence of roughness on the wettability of mineral surfaces certainly existed [6,8,9,22,23,26,29,33]. In the flotation process, due to the same metal cation calcium in the lattice, apatite and dolomite showed similar crystal properties and surface physical and chemical properties, so it is difficult to achieve effective separation.…”

Tuning the Morphology and Surface Property of Mineral Particles by Grinding Media

“…Those differences in the shape indexes between the ball and rod mill particles could be explained by the fact that breakage mechanism determines particle shape in all comminution equipment. The rod mill exercises line loads on the particles and the dominant breakage mechanism is the impact, during which the sharp edges are created, turning the particle to become more elongated [13]. Whereas the ball mill exerts point loads on the particles, and the predominant breaking forces are abrasion and chipping, which could eliminate the corners and sharp edges of the particles, turning them to become more rounded [14,15].…”

“…Different grinding methods possess different breakage mechanisms and accordingly, produce particles with different shapes or morphologies [12]. For the rod mill, line loads are exerted on the mineral particles, and the predominant breaking forces are the impact which can produce particles with sharp edges [13]. In contrast, the ball mill imposes point loads on the particles, so that the main forces are abrasion and chipping which can trim off the corners and sharp edges of particles efficiently [14,15].…”