Solubility behavior of titanium(IV) oxide in alkaline media at elevated temperatures

Journal Article · Thu Jul 01 00:00:00 EDT 1993 · Journal of Solution Chemistry; (United States)

DOI:https://doi.org/10.1007/BF00646781· OSTI ID:5646543

Ziemniak, S E; Jones, M E; Combs, K E.S. ^[1]

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1. Knolls Atomic Power Laboratory, Schenectady, NY (United States)

A platinum-lined, flowing autoclave facility was used to investigate the solubility behavior of titanium dioxide (TiO[sub 2]) in aqueous sodium phosphate, sodium hydroxide and ammonium hydroxide solutions between 17 and 288[degrees]. Baseline Ti(IV) solubilities were found to be on the order of one nanomolal, which were enhanced by the formation of anionic hydroxo- and phosphato-complexes. The measured solubility behavior was examined via a titanium(IV) ion hydrolysis/complexing model and thermodynamic functions for the hydrolysis/complexing reaction equilibria were obtained from a least-squares analysis of the data. The existence of three new Ti(IV) ion complexes is reported for the first time: Ti(OH)[sub 4](HPO[sub 4])[sup 2[minus]], Ti(OH)[sub 5](H[sub 2]PO[sub 4])[sup 2[minus]] and Ti(OH)[sub 5](HPO[sub 4])[sup 3[minus]]. The triply-charged anionic complex was the dominant Ti(IV) species in concentrated, alkaline phosphate solutions at elevated temperatures. This complex is expected to exhibit C.N. = 4 (i.e., Ti(OH)[sub 2]OPO[sup 3[minus][sub 4]]). A summary of thermochemical properties for species in the systems TiO[sub 2]-H[sub 2]O and TiO[sub 2]-P[sub 2]O[sub 5]-H[sub 2]O is also provided.

• OSTI ID: 5646543
• Journal Information: Journal of Solution Chemistry; (United States), Journal Name: Journal of Solution Chemistry; (United States) Vol. 22:7; ISSN 0095-9782; ISSN JSLCAG
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
AMMONIUM COMPOUNDS
AMMONIUM HYDROXIDES
ANIONS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
COMPLEXES
COORDINATION NUMBER
DECOMPOSITION
HYDRATES
HYDROGEN COMPOUNDS
HYDROLYSIS
HYDROXIDES
INORGANIC ACIDS
IONS
LEAST SQUARE FIT
LYSIS
MAXIMUM-LIKELIHOOD FIT
NUMERICAL SOLUTION
OXIDES
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORIC ACID
PHOSPHORUS COMPOUNDS
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SODIUM PHOSPHATES
SOLUBILITY
SOLVOLYSIS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TITANIUM COMPLEXES
TITANIUM COMPOUNDS
TITANIUM HYDROXIDES
TITANIUM OXIDES
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS