Increasing Fluidity of Stainless Steel Dust by Adding Nano-Silica Glidant

Large amounts of dust are generated during stainless steel production; however, the extremely poor fluidity of this dust prevents its transportation by pipeline. The effects of glidants and their particle size, addition amount, and mixing time on the fluidity of stainless steel dust (SSD) were systematically investigated. When nano-silica (particle size of 200 nm) was used as a glidant, and the added amount and mixing time were set to 5% and 10 min, respectively, the SSD exhibited the best fluidity. Generally, the repose angle and Hausner ratio (HR) of the SSD decreased by 16.8% and 14.5% to 40.05° and 1.47, respectively. In addition, the adhesion force reduced from 36 nN to 7 nN. The van der Waals force among the SSD particles also reduced, and the electrostatic repulsion force increased, providing a feasible solution to SSD fluidity problems. However, it should be noted that this study was limited to laboratory-scale measurements, and industrial-scale validation is required in future work.