Investigations on SYNROC mineralogy. Progress report
Progress reports are presented for the following projects: (1) factors influencing the leaching performance of hollandiate; (2) incorporation of uranium and rare earths into zirconolite; (3) reconnaissance studies of the stability relations of Ca-Ti-Al phases in SYNROC C formulations; (4) immobilization of highly aluminous sludges; (5) SYNROC D formulations produced by sintering in air; (6) crystallization behavior of interstitial glass in SYNROC D formulations. Some of the highlights are: (1) leaching performance of all hollandites irrespective of preparation technique, can be improved by hot-pressing under specific controlled redox conditions, below Ni-NiO; (2) there is no satisfactory crystal-chemical reason why the leaching performance of Ti/sup 3 +/-bearing hollandite should be superior to that of Al/sup 3 +/ hollandite; (3) experiments have shown that the zirconolite lattice can accept up to 30% rare earths (Sm/sub 2/O/sub 3/) before becoming destabilized in favor of pyrochlore or a related f.c.c. structure; (4) SYNROC zirconolites will therefore be well below their saturation limits in rare earths and trivalent actinides; (5) experiments have established that the Ca-Ti-Al phase (CTA) is compatible with perovskite, hollandite and zirconolite; (6) magnetoplumbite-type phases coexists with hollandite, perovskite, zirconolite and Fe-bearing pseudobrookite, but do not coexist with the CTA phase CaTi/sub 3/Al/sub 8/O/sub 19/; (7) experiments demonstrated that it is not possible to convert highly aluminous sludges to a waste form comprising zirconolite, perovskite, spinel and nepheline plus corundum, by adding appropriate minimum amounts of the inert SYNROC additives (CaO, TiO/sub 2/, ZrO/sub 2/, SiO/sub 2/); (8) sintering of SYNROC D in air at temperatures just above the solidus (1200 to 1250/sup 0/C) produced a dense compact ceramic, but the optimum SYNROC-D mineralogy was not produced. (ATT)
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5516706
- Report Number(s):
- UCRL-15436; ON: DE82011072
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
360602 -- Other Materials-- Structure & Phase Studies
360604 -- Materials-- Corrosion
Erosion
& Degradation
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BARIUM COMPOUNDS
BARIUM OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
DATA
DISSOLUTION
EXPERIMENTAL DATA
GLASS
HOLLANDITE
INFORMATION
LEACHING
MANAGEMENT
MATERIALS
MINERALOGY
MINERALS
NUMERICAL DATA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITE
PEROVSKITES
PHASE STUDIES
PROCESSING
RADIOACTIVE WASTE PROCESSING
RESEARCH PROGRAMS
ROCKS
SEPARATION PROCESSES
SYNROC PROCESS
SYNTHESIS
SYNTHETIC MATERIALS
SYNTHETIC ROCKS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
WASTE MANAGEMENT
WASTE PROCESSING
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES
ZIRCONOLITE