Identification of chemical processes influencing constituent mobility during in-situ uranium leaching

Conference · Sun Jul 01 04:00:00 EDT 1984

OSTI ID:6067822

Sherwood, D R; Hostetler, C J; Deutsch, W J

In-situ leaching of uranium has become a widely accepted method for production of uranium concentrate from ore zones that are too small, too deep, and/or too low in grade to be mined by conventional techniques. One major environmental concern that exists with in-situ leaching of uranium is the possible adverse effects mining might have on regional ground water quality. The leaching solution (lixiviant), which extracts uranium from the ore zone, might also mobilize other potential contaminants (As, Se, Mo, and SO/sub 4/) associated with uranium ore. Column experiments were performed to investigate the geochemical interactions between a lixiviant and a uranium ore during in-situ leaching and to identify chemical processes that might influence contaminant mobility. The analytical composition data for selected column effluents were used with the MINTEQ code to develop a computerized geochemical model of the system. MINTEQ was used to calculate saturation indices for solid phases based on the composition of the solution. A potential constraint on uranium leaching efficiency appears to be the solubility control of schoepite. Gypsum and powellite solubilities may limit the mobilities of sulfate and molybdenum, respectively. In contrast, the mobilities of arsenic and selenium were not limited by solubility constraints, but were influenced by other chemical interaction between the solution and sediment, perhaps adsorption. Bulk chemical and mineralogical analyses were performed on both the original and leached ores. Using these analyses together with the column effluent data, mass balance calculations were performed on five constituents based on solution chemical analysis and bulk chemical and ..gamma..-spectroscopy analysis for the sediment. 6 references, 10 figures, 10 tables.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6067822
• Report Number(s): PNL-SA-12173; CONF-8408134-1; ON: DE85003645
• Country of Publication: United States
• Language: English

Related Subjects

050300 -- Nuclear Fuels-- Mining-- (-1987)
053000* -- Nuclear Fuels-- Environmental Aspects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ARSENIC
CHEMISTRY
CONTROL
DATA
DISPERSIONS
DISSOLUTION
ELEMENTS
ENVIRONMENTAL QUALITY
EXPERIMENTAL DATA
GEOCHEMISTRY
GROUND WATER
HYDROGEN COMPOUNDS
INFORMATION
LEACHATES
LEACHING
METALS
MINING
MIXTURES
MOLYBDENUM
NUMERICAL DATA
ORES
OXYGEN COMPOUNDS
POLLUTION CONTROL
SATURATION
SELENIUM
SEMIMETALS
SEPARATION PROCESSES
SOLUTION MINING
SOLUTIONS
SULFATES
SULFUR COMPOUNDS
TRANSITION ELEMENTS
URANIUM ORES
WATER
WATER POLLUTION CONTROL
WATER QUALITY