The surface charge of KCl as influenced by crystal lattice defects

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Journal of Colloid and Interface Science; (United States)

DOI:https://doi.org/10.1006/jcis.1994.1089· OSTI ID:7205472

Yalamanchili, M R; Miller, J D ^[1]

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1. Univ. of Utah, Salt Lake City, UT (United States). Dept. of Metallurgical Engineering

Recently, nonequilibrium electrokinetic measurements using laser-Doppler electrophoresis were reported for alkali halides and the sign of their surface charge was thus determined. These results are generally as expected from simplified lattice ion hydration theory with KCl, under normal circumstances, being the most significant exception. In this regard, lattice defects (F centers and oxygen imperfections) have been found to influence the surface charge of KCl and its electrophoretic mobility. In particular, the presence of oxygen defect states in the crystal lattice has been found to be responsible for KCl's unexpected behavior. The concentration of oxygen defect states in KCl, as characterized by UV/Vis absorption, was varied in order to study their influence on the electrokinetic behavior and subsequently on the flotation response of KCl. At low oxygen contents (<60 ppm) KCl is positively charged as expected from lattice ion hydration theory. However, typically, KCl contains substantial oxygen (>300 ppm), sufficient to impart a negative surface charge and this accounts for the selective flotation of KCl from NaCl by heterocoagulation with oppositely charged alkyl amine hydrochloride collector colloids.

• DOE Contract Number: FG03-93ER14315
• OSTI ID: 7205472
• Journal Information: Journal of Colloid and Interface Science; (United States), Journal Name: Journal of Colloid and Interface Science; (United States) Vol. 163:1; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical &amp; Physicochemical Properties
ALKALI METAL COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
CORRELATIONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTROPHORESIS
FLOTATION
HALIDES
HALOGEN COMPOUNDS
ORE PROCESSING
POTASSIUM CHLORIDES
POTASSIUM COMPOUNDS
POTENTIALS
PROCESSING
SEPARATION PROCESSES
SURFACE POTENTIAL