Wettability of non‐metallic inclusions and its impact on bubble‐induced flotation kinetics

Ceramic refractory bubbling devices may be applied in the steel ladle to induce the flotation of non‐metallic inclusions to the slag phase. These inclusions have many origins along the steelmaking process and induce a detrimental effect on the mechanical properties of these metals. Therefore, the design of high‐performance ceramic plugs relies on understanding the fundamentals of non‐metallic inclusions captured by the gas bubbles. This study investigated the flotation dynamics of hydrophobic and hydrophilic hollow glass particles through experimentation using a water model and quantifying the particle concentration via light scattering. Both types of particles exhibited a comparable natural flotation removal rate, whereas a 40% increase for hydrophobic particles was observed when introducing 1.1 mm bubbles (at 25 NL/h) enhancing the efficiency from 43.1% to 65.2%. For hydrophilic particles, the efficiency increased from 59.1% to 86.2% when bubbles were injected into the system, whereas the removal rate decreased by 2.1‐fold. The consequence of the practice of inert gas purging to remove non‐metallic inclusions is also discussed.