Laboratory studies on natural restoration of ground water after in-situ leach uranium mining

Conference · Sun May 01 04:00:00 EDT 1983

OSTI ID:6284434

Bell, N E; Deutsch, W J; Serne, R J

When uranium is mined using in-situ leach techniques, the chemical quality of the ground water in the ore-zone aquifer is affected. This could lead to long-term degradation of the ground water if restoration techniques are not applied after the leaching is completed. Pacific Northwest Laboratory (PNL), is conducting an NRC-sponsored research project on natural restoration and induced-restoration techniques. Laboratory studies were designed to evaluate the ability of the natural system (ore-zone sediments and groundwater) to mitigate the effects of mining on aquifer chemistry. Using batch and flow-through column experiments (performed with lixiviant (leaching solution) and sediments from the reduced zone of an ore-zone aquifer), we found that the natural system can lower uranium and bicarbonate concentrations in solutions and reduce the lixiviant redox potential (Eh). The change in redox potential could cause some of the contaminants that were dissolved during the uranium leaching operation to precipitate, thereby lowering their solution concentration. The concentrations of other species such as calcium, potassium, and sulfate increased, possibly as a result of mineral dissolution and ion exchange. In this paper, we describe the experimentally determined mobility of contaminants after in-situ leach mining, and discuss the possible chemical process affecting mobility.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6284434
• Report Number(s): PNL-SA-10973; CONF-830561-1; ON: DE83013248
• Country of Publication: United States
• Language: English

Related Subjects

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11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
580400 -- Geochemistry-- (-1989)
ACTINIDES
ALKALI METALS
ALKALINE EARTH METALS
BORIC ACID
CALCIUM
CHEMISTRY
CHLORINE
DISPERSIONS
DISSOLUTION
ELEMENTS
ENVIRONMENTAL IMPACTS
GROUND WATER
HALOGENS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LEACHATES
LEACHING
MAGNESIUM
METALS
MINES
MINING
MIXTURES
MOBILITY
NONMETALS
ORES
OXYGEN COMPOUNDS
POTASSIUM
REDOX POTENTIAL
SEPARATION PROCESSES
SILICIC ACID
SODIUM
SOLUTION MINING
SOLUTIONS
SULFATES
SULFUR COMPOUNDS
UNDERGROUND FACILITIES
URANIUM
URANIUM MINES
URANIUM ORES
WATER
WATER CHEMISTRY