Mechanism of saleeite formation at the Koongarra secondary ore deposit
- Univ. of Tokyo (Japan). Mineralogical Inst.
- JAERI, Tokai, Ibaraki (Japan). Environmental Geochemistry Lab.
- Ehime Univ., Matsuyama, Ehime (Japan). Dept. of Earth Sciences
Rock samples in the secondary ore deposit at Koongarra, Australia, were examined mineralogically to clarify the formation mechanism of saleeite (Mg(UO{sub 2}){sub 2}(PO{sub 4}){sub 2}.10H{sub 2}O), a major secondary uranium mineral in the secondary ore deposit. Sklodowskite (MgSi{sub 2}U{sub 2}O{sub 11}.7H{sub 2}O) veinlets, present upstream of the ore deposit, are partially replaced by saleeite. Most grains of apatite (Ca{sub 5}(PO{sub 4}){sub 3}F), an accessory mineral of the host rock, are also replaced by saleeite. Thermodynamic calculations by EQ3NR showed that the present Koongarra ground waters are undersaturated with respect to saleeite and also suggested that saleeite can be precipitated under the condition of higher U or P concentrations. Such conditions can be created at the reaction interfaces of dissolving sklodowskite, which releases U, or dissolving apatite, which releases P. The present study indicates that saleeite is formed by local microscale saturation upstream of the secondary ore deposit, which is different from the formation mechanism of saleeite downstream of the ore deposit, where saleeite microcrystals of 1--20 nm in size form by catalysis on iron minerals, the weathering products of the host rock.
- OSTI ID:
- 264484
- Report Number(s):
- CONF-951155-; ISBN 1-55899-315-0; TRN: 96:016629
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 27 Nov - 1 Dec 1995; Other Information: PBD: 1996; Related Information: Is Part Of Scientific basis for nuclear waste management 19; Murphy, W.M. [ed.] [Southwest Research Inst., San Antonio, TX (United States)]; Knecht, D.A. [ed.] [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)]; PB: 957 p.; Materials Research Society symposium proceedings, Volume 412
- Country of Publication:
- United States
- Language:
- English
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