Kinetics of boehmite precipitation from supersaturated sodium aluminate solutions

Skoufadis, C; Panias, D; Paspaliaris, I

dc.contributor.author	Skoufadis, C	en
dc.contributor.author	Panias, D	en
dc.contributor.author	Paspaliaris, I	en
dc.date.accessioned	2014-03-01T01:19:05Z
dc.date.available	2014-03-01T01:19:05Z
dc.date.issued	2003	en
dc.identifier.issn	0304-386X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15373
dc.subject	Aluminate solutions	en
dc.subject	Boehmite precipitation	en
dc.subject	Kinetics	en
dc.subject.classification	Metallurgy & Metallurgical Engineering	en
dc.subject.other	Activation energy	en
dc.subject.other	Alumina	en
dc.subject.other	Bauxite ore treatment	en
dc.subject.other	Hydrolysis	en
dc.subject.other	Precipitation (chemical)	en
dc.subject.other	Reaction kinetics	en
dc.subject.other	Solubility	en
dc.subject.other	Solutions	en
dc.subject.other	Supersaturation	en
dc.subject.other	Seed ratio (SR)	en
dc.subject.other	Aluminum metallurgy	en
dc.title	Kinetics of boehmite precipitation from supersaturated sodium aluminate solutions	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0304-386X(02)00165-2	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0304-386X(02)00165-2	en
heal.language	English	en
heal.publicationDate	2003	en
heal.abstract	This work presents the effect of the most important parameters, the precipitation temperature, the sodium hydroxide concentration and the initial seed ratio (SR) in the solution, on the boehmite precipitation from supersaturated sodium aluminate solutions. A kinetic model that describes the experimental data was developed. According to that model, boehmite precipitation follows second order reaction kinetics and has activation energy of 89 kJ/mol. The orders of the precipitation reaction with respect to the initial sodium hydroxide concentration and the initial seed ratio are estimated to be - 1.8 and 0.54, respectively. The most important result is that the boehmite precipitation reaches an apparent equilibrium stage at which the alumina concentration is much higher compared to the value of the boehmite solubility under the same experimental conditions. The results reveal that the boehmite precipitation is a self-decelerated process and the observed kinetic inhibitions are related to the sodium hydroxide concentration in the supersaturated solution. Finally, a mechanistic interpretation of the experimental data is presented based on the concept of the surface precipitation of boehmite on the active sites of the boehmite seed. (C) 2003 Elsevier Science B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Hydrometallurgy	en
dc.identifier.doi	10.1016/S0304-386X(02)00165-2	en
dc.identifier.isi	ISI:000181303500009	en
dc.identifier.volume	68	en
dc.identifier.issue	1-3	en
dc.identifier.spage	57	en
dc.identifier.epage	68	en