Proving the existence of nanobubbles produced by hydrodynamic cavitation and their significant effects in powder flotation

Autor: Mohammad Noaparast, Ziaeddin Pourkarimi, Bahram Rezai, S. Chehreh Chelgani, Anh V. Nguyen
Rok vydání: 2021
Předmět:
Zdroj: Advanced Powder Technology. 32:1810-1818
ISSN: 0921-8831
DOI: 10.1016/j.apt.2021.03.039
Popis: Selective attachment of nanobubles (NBs) generated in different conditions on the surface of valuable minerals during flotation separation was a challenge that needs to be addressed. This investigation filled this gap and proved the existence of NBs on the target mineral's surface and their selective effectiveness through the process. The bubble size analysis results showed that the mean diameter of bubbles was between 60 and 70 nm; thus, they could be correctly called “nanobubbles”. Flotation test results showed a significant increase in the flotation recovery (by 37%) and grade (more than 1%) of fine phosphate ore sample (d80: 37 µm) using NBs that generated in the presence of collector. Interestingly, surface analyses of flotation products showed that the amounts of flotation collector adsorbed onto the surface of floated particles was decreased in the presence of NBs compared with their absence. The change in the particle surface (zeta) potential in the presence of NBs also provides additional evidence of NBs “adsorbed” (i.e., the surface NBs) onto the particle surface. These results indicated that NBs produced by hydrodynamic cavitation could adsorb onto the target mineral particles. This adsorption could change their surface properties, improve their hydrophobicity and surface potentials, and enhanced the bubble-particle attachment in flotation.
Databáze: OpenAIRE