Investigation on the Effect of Surface Roughness on the Adhesion of Water Droplets on Calcite Surface

In this paper, calcite was selected as the research object, and surface roughness was taken as the key point, the effect of surface roughness on the adhesion of water droplets on calcite surface before and after conditioning with sodium oleate was investigated. In addition, the measured adhesive force and the calculated adhesive force were compared. Experimental results revealed that the surface of natural calcite was hydrophilic; with the increase of surface roughness, the contact angle of water droplets on the surface of natural calcite decreased while both the base diameter and the adhesion force increased. However, the surface of calcite after conditioning with 30 mg/L NaOL at pH value of 10 became hydrophobic; with the increase of surface roughness, the contact angle of water droplets on the conditioned surface increased while both the base diameter and the adhesive force decreased. Meanwhile, the measured adhesive force agreed well with the calculated force. Therefore, the adhesion characteristics of water droplets on calcite surface could be regulated by controlling surface roughness, which could provide a reference for the regulation of the floatability of calcite by surface roughness.