Journal
JOURNAL OF COLLOID AND INTERFACE SCIENCE
Volume 636, Issue -, Pages 413-424Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jcis.2023.01.038
Keywords
Soluble minerals; Collector colloid; Collin concept; Potash flotation
Categories
Ask authors/readers for more resources
Flotation of water-soluble KCl and NaCl minerals in brines is significant for K-fertilizer production, but its mechanism remains controversial. This study investigates the interaction between dissolved salt ions and collector colloids, as well as the changes in interfacial properties, to gain a molecular understanding of salt flotation. The findings suggest that ion specificity plays a crucial role in salt crystal flotation via collector colloid-crystal attraction.
Hypothesis: Flotation of water-soluble KCl and NaCl minerals in brines is significant for K-fertilizer production, but its mechanism is controversial. Dissolved salt ions are expected to change the physicochemical properties of solvents, interfaces, and collector colloids, thereby affecting flotation significantly. Experiments: Flotation experiments of KCl and NaCl crystals in brines were conducted using potassium and sodium laurates as collectors. Contact angle (CA) and surface tension measurements, X-ray photoelectron spectroscopy (XPS) analysis, and molecular dynamics simulations (MD) were applied to gain a molecular understanding of changing interfacial properties and crystal-collector colloid interactions in the presence of dissolved ions in terms of salt flotation. Findings: While K. ions activate the NaCl crystal flotation, Na. ions depress the KCl crystal flotation, in agreement with the studies of CA, XPS, and MD results with these crystals. XPS results showed no collector adsorption at crystal surfaces which is a requirement of conventional flotation and presents a new theoretical challenge. We argue the crucial role of ion specificity: Na-laurate colloids adsorb at the bubble surface as a monolayer but solvent-separated from KCl crystals, inhibiting their flotation, or in interactive contact with NaCl crystals, enhancing their flotation. Increasing K. concentration weakens NaCl crystal hydration, increasing Na-laurate colloid attraction with crystals for better flotation. The Contact Interactive Collector Colloid (CICC) and Solvent-separated Interactive Collector Colloid (SICC) hydration states are critical to salt crystal flotation via collector colloid-crystal attraction by dispersion forces. (c) 2023 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available