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Destabilization‐Enhanced Centrifugation of Metalworking Oil‐in‐Water Emulsions: Effect of Demulsifying Agents
Author(s) -
Allende D.,
Cambiella Á.,
Benito J. M.,
Pazos C.,
Coca J.
Publication year - 2008
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.200700018
Subject(s) - emulsion , flocculation , demulsifier , zeta potential , chemistry , metalworking , chromatography , chemical engineering , oil droplet , materials science , organic chemistry , metallurgy , nanoparticle , engineering
The effect of a commercial flocculant (Alpacon® WS009) and two coagulant salts (CaCl 2 and AlCl 3 ) on the stability of metalworking oil‐in‐water (O/W) emulsions was examined. Two O/W emulsions were tested: a fresh emulsion, prepared in the laboratory from a commercial concentrate, and a waste metalworking emulsion, provided by a local waste management company, with initial oil concentrations of 32900 and 16900 mg/L, respectively. The emulsion stability was studied at different demulsifier concentrations, temperatures and pH through centrifugation tests, zeta potential and multiple light scattering measurements. Emulsion breakdown is explained by electrostatic repulsion of oil droplets and steric interactions. The former was observed for the laboratory emulsion, while the latter was observed for the waste emulsion. Aluminum chloride was the only effective agent for demulsifying both emulsions.