Ultralow Adhesion and Phase Change Behaviors of Sulfur Droplets on the Superhydrophobic Surface and Its Application in the Granulation Process

Traditional sulfur granulation process is often accompanied by high dust and mechanical friction, which are dangerous and harmful to the environment. In this work, the application of the superhydrophobic surface to sulfur granulation is expected to solve the above problem. Two superhydrophobic metal sheets were prepared, and the rolling angles of the two samples are both less than 10°. The contact angles of liquid sulfur are 152.7 ± 0.5 and 151.3 ± 0.1°, respectively. The adhesion rates of both samples are less than 0.5 wt %. The solidifying process of a sulfur drop on the superhydrophobic surface was recorded and simulated, conforming that the substrate temperature has a great influence on the solidifying process. Based on the above findings, static granulation and rolling to granulation were proposed. The product obtained by the two methods has uniform particle size distribution and excellent compressive strength, showing a good industrial application prospect. This study provides a referral strategy for an economical and environmentally friendly sulfur granulation process.