THE ROLE OF HUMIC ACIDS IN THE GEOCHEMISTRY OF URANIUM

Technical Report · Fri Oct 31 04:00:00 EST 1958

OSTI ID:4307201

Vine, J D; Swanson, V E; Bell, K G

Carbonaceous matter is probably the most characteristic component of sedimentary rocks containing abnormal concentrations of uranium, but much evidence suggest that only certain types of carbonaceous matter have the capacity to assimilate, fix, or transport uratter in sedimentary rocks is considered berc as a complex, gradational series of organic remains with three distinct endmembers--decayed wood, hydrocarbons, and carbon Two major categories of carbonaceous matter may be recognized: sapropelic and-humic. Sapropelic matter is rich in hydrogen and yields bitumems. Humic matter is rich in oxygen and yields humic acid extracts to alkaline solutions. Carbon is the metamorphic end product of both humic and sapropelic matter. Solid humic matter and the extracted humic acids are the important carbonaceous materials in the geochemical cycle of uranium. Experimental results show that humic substances are capable of assimilating 5 percent or more of uranium by dry weight from uranyl solutions forming uranyl humate. Solid humic matter is the principal constituent of peat, lignite, and of the dispersed carbonaceous matter in non-marine sedimentary rooks, Natural alkaline solutions such as sodium carbonate ground water readily extract humic acids from the solid humic matter to form a colloidal solution; upon acidification or addi- tion of some salts (e.g., those of calcium), the dispersed humic acids flocculate to form a reddish-brown gel. Humic acids and humates readily remove uranium from solution by adsorption, ion exchange, or chemical complexing. Once assimilated, the uranium remains fixed under most natural conditions of transportation and deposition Some carbonaceous uranium ore deposits of the type commonly but erroneously called ''uraniferous asphaltite'' are thought to represent deposits of uranyl humnates that have been carbonized and indurated by alpha-particle irradiation Evidence is presented to show that a small humic-matter component of the carbonaceous material in marine black shales may be responsible for retaining most of the uranium disseminated in these rocks. (auth)

• Research Organization: Geological Survey, Denver
• NSA Number: NSA-12-014737
• OSTI ID: 4307201
• Report Number(s): A/CONF.15/P/779
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDITY
ADSORPTION
ALPHA PARTICLES
BITUMENS
CALCIUM COMPOUNDS
CARBON
CARBON COMPOUNDS
CHEMICAL REACTIONS
CHEMISTRY
COAGULATION
COAL
COLLOIDS
CONCENTRATION
DEPOSITS
DISPERSIONS
DISTRIBUTION
GEOCHEMISTRY
GROUND WATER
HUMIC ACID
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXIDES
ION EXCHANGE
IRRADIATION
LEACHING
LIGNITE
MEASURED VALUES
ORGANIC ACIDS
PEAT
PRECIPITATION
PYROLYSIS
QUANTITY RATIO
ROCKS
SALTS
SODIUM CARBONATES
SOLIDS
SOLUTIONS
TESTING
TRANSPORT
URANIUM
URANIUM COMPLEXES
URANIUM COMPOUNDS
URANIUM ORES
URANYL COMPOUNDS