Silicon and aluminum removal from ilmenite concentrates by alkaline leaching

Mazzocchitti, G; Giannopoulou, I; Panias, D

dc.contributor.author	Mazzocchitti, G	en
dc.contributor.author	Giannopoulou, I	en
dc.contributor.author	Panias, D	en
dc.date.accessioned	2014-03-01T01:31:54Z
dc.date.available	2014-03-01T01:31:54Z
dc.date.issued	2009	en
dc.identifier.issn	0304-386X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19968
dc.subject	Alkaline processing	en
dc.subject	Ilmenite concentrate	en
dc.subject	Pressure leaching	en
dc.subject	Silicon leach	en
dc.subject.classification	Metallurgy & Metallurgical Engineering	en
dc.subject.other	Alumina	en
dc.subject.other	Aluminum	en
dc.subject.other	Dissolution	en
dc.subject.other	Ilmenite	en
dc.subject.other	Metal refining	en
dc.subject.other	Nonmetals	en
dc.subject.other	Oxide minerals	en
dc.subject.other	Pressure effects	en
dc.subject.other	Sodium	en
dc.subject.other	Thermal effects	en
dc.subject.other	Titanium	en
dc.subject.other	Alkaline leaching	en
dc.subject.other	Alkaline processing	en
dc.subject.other	Aluminum contents	en
dc.subject.other	Caustic leaching	en
dc.subject.other	Crucial parameters	en
dc.subject.other	Economic studies	en
dc.subject.other	Ferrotitanium	en
dc.subject.other	Grade b	en
dc.subject.other	Hydrometallurgical process	en
dc.subject.other	Iron contents	en
dc.subject.other	Leaching kinetics	en
dc.subject.other	Pressure leaching	en
dc.subject.other	Retention time	en
dc.subject.other	Secondary precipitates	en
dc.subject.other	Selective leaching	en
dc.subject.other	Silicon contents	en
dc.subject.other	Sodium hydroxide concentrations	en
dc.subject.other	Sodium hydroxides	en
dc.subject.other	Zeolitic phase	en
dc.subject.other	Leaching	en
dc.title	Silicon and aluminum removal from ilmenite concentrates by alkaline leaching	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.hydromet.2008.12.001	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.hydromet.2008.12.001	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	In this paper, a hydrometallurgical process for the treatment of ilmenite concentrates is developed, in order to reduce the silicon content to the maximum allowed value for the production of "grade B" ferrotitanium. The process was based on pressure leaching with sodium hydroxide and the effect of the main leaching parameters, namely the temperature, sodium hydroxide concentration and retention time, on the efficiency of silicon removal was studied. Caustic leaching of the ilmenite concentrates resulted in the removal of silicon, as well as of aluminum, without affecting the contents of titanium and iron. Leaching temperature and the retention time were proved as crucial parameters for the effective dissolution of silicon. Besides, these parameters affected directly the secondary precipitation of silicon and aluminum as a zeolitic phase, which polluted the treated ilmenite concentrate. Leaching kinetics determined the feasibility of the process, leading to the development of two optimized alternatives. The first alternative achieved the reduction of silicon and aluminum content to 0.32% and 0.61%, respectively, after 72 h leaching at 120 degrees C. This alternative necessitated a leached solids washing stage in order to separate the formed precipitate from the treated ilmenite concentrate. The second alternative achieved to reduce silicon and aluminum to 0.29% and 0.59%, respectively, after 1 h leaching at 200 degrees C, while avoided the formation of the secondary precipitate. Both alternatives achieved the selective leaching of silicon and aluminum without affecting titanium and iron content of the ilmenite concentrate. The applicability of each alternative is a matter of detailed technical and economic studies. (C) 2008 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Hydrometallurgy	en
dc.identifier.doi	10.1016/j.hydromet.2008.12.001	en
dc.identifier.isi	ISI:000264651700009	en
dc.identifier.volume	96	en
dc.identifier.issue	4	en
dc.identifier.spage	327	en
dc.identifier.epage	332	en