Research on the role of nanobubbles in coal slime flotation
XING Yanwei
Abstract：To address the technical challenge of efficiently separating fine,difficult-to-wash coal slime using tra-ditional flotation methods,a study was conducted using coal slime from the Guandi Coal Preparation Plant as the sample.A self-developed nanobubble flotation system was employed to investigate the stability of hydrodynam-ic cavitation-generated nanobubbles and their impact on flotation performance,while also analyzing the mechan-ism by which nanobubbles enhance fine particle separation.The results indicate that after more than 5 minutes of cavitation treatment,nanobubble size stabilized within the range of 175～225 nm,maintaining high stability even after one hour of standing.In the presence of nanobubbles,a frother dosage of 0.3 kg/t achieved a combust-ible recovery rate of 91%,representing a 25%reduction in frother consumption compared to conditions without nanobubbles.When the aeration rate ranged from 0.4 cm/s to 1.6 cm/s,the combustible recovery rate in the nan-obubble-containing slurry system remained around 90%.However,the ash content of the product increased with higher aeration rates,attributed to nanobubbles enhancing the hydrophobicity of coal particles while simultan-eously increasing the probability of attachment of less hydrophobic mineral particles.Nanobubbles exhibit ex-cellent stability and significantly enhance coal slime flotation through multiple mechanisms,including promot-ing the aggregation of fine particles,capillary bridging,and destabilizing liquid films.This provides a new path-way for the efficient separation of fine-grained coal.
Keywords：coal slime flotationnanobubblessingle bubble attachment experimentfrother dosageaeration ratecombustible recovery rate
Publication Date：2025-08-31
Online Publishing Date：2025-12-29(First online date of this platform, not the publication date of the document)
Pages：7( 40-46 )