SYSTEMS BETWEEN PHOSPHORIC ANHYDRIDE AND THE DIOXIDES OF URANIUM AND THORIUM

Journal Article · Mon Apr 01 04:00:00 EST 1963 · Annali di Chimica (Rome) (Italy)

OSTI ID:4116922

Burdese, A; Borlera, M L

In both the UO/sub 2/-- P/sub 2/O/sub 5/ and ThO/sub 2/- P/sub 2/O/sub 5/ syst ems 5 compounds were found with the ratio MO/sub 2/: P/sub 2/O/sub 5/ equal to 0.5, isomorphic and completely soluble in the solid state, as are the metaphosphates; above 1000 deg C the metaphosphates form pyrophosphates, losing P/ sub 2/O/sub 5/. The cubic and rhombic forms of the pyrophosphates are isomorphic, but their regions of stability correspond to different temperature intervals and the relative solubility of the rhombic pyrophosphates in the solid state is therefore low. Compounds with high ratios of metal oxide to P/sub 2/O/ sub 5/ are stable only at high temperatures: (UO)/sub 2/P/sub 2/O/sub 7/ is formed above 900 deg C; (ThO)/sub 2/ P/sub 2/O/sub 7/ above 1550; (UO)/sub 3/(PO/ sub 4/)/sub 2/ above 1200; (ThO)/sub 3/(PO/sub 4/)2 a bove 1150 deg C. Both of these pairs have low reciprocal solubility and are not isomorphic. Tentative phase diagrams are illustrated. (BBB)

• Research Organization: Politecnico, Turin
• NSA Number: NSA-18-012049
• OSTI ID: 4116922
• Journal Information: Annali di Chimica (Rome) (Italy), Journal Name: Annali di Chimica (Rome) (Italy) Vol. Vol: 53; ISSN ANCRA
• Country of Publication: Country unknown/Code not available
• Language: Italian

Related Subjects

ALLOTROPY
CHEMISTRY
CRYSTALS
PHASE DIAGRAMS
PHOSPHORUS OXIDES
SOLIDS
SOLUBILITY
STABILITY
TEMPERATURE
THORIUM OXIDES
THORIUM PHOSPHATES
URANIUM DIOXIDE
URANIUM PHOSPHATES