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

Technical Report · Wed Jan 01 00:00:00 EST 1992

OSTI ID:5546304

Ziemniak, S E; Jones, M E; Combs, K E.S.

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 290 and 560 K. 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 =}, Ti(OH){sub 5}(H{sub 2}PO{sub 4}){sup =} 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{sub 4}{sup 3{minus}}). 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. 21 refs., 9 figs., 6 tabs.

• Research Organization: Knolls Atomic Power Lab., Schenectady, NY (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC12-76SN00052
• OSTI ID: 5546304
• Report Number(s): KAPL-4729; ON: DE92009551
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
RUTILE
SOLUBILITY
TITANIUM PHOSPHATES
THERMODYNAMIC PROPERTIES
AQUEOUS SOLUTIONS
AUTOCLAVES
TEMPERATURE DEPENDENCE
TITANIUM OXIDES
CHALCOGENIDES
DISPERSIONS
MATERIALS
MINERALS
MIXTURES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
SOLUTIONS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
400201 - Chemical & Physicochemical Properties