RECOVERY OF URANIUM FROM CHATTANOOGA SHALE
A variety of methods for the recovery of uranium has been investigated. Hot countercurrent leaching and oxygen-pressure leaching have beenfound to be effec-tive, High-temperature chlorination, though not worked out, is another possible method of recovery. Countercurrent leaching at solid-to-liquid ratios in the range 0.5:2 with seven refluxing leach stages of one-half hour each and a sulfuric acid feed of 7.1% results in the extraction of 72% of the uranium. The effects of varying the number of states, the shale to product ratio, the particle size, the time per stage, and the acid feed were investigated. Oxygen-pressure leaching at elevated temperatures and pressure in the range of 150 to 175 deg C and 100 to 150 psia gave yields of 80% or better. The effects of leaching time, temperaturc, oxygen pressure, gas bleeding, and the ratio of shale to water and to recycled pregnant liquor were studied. A continuous process demonstration unit was set up and operated at a feed rate of 88 lb of shale per hour. The results thereof confirmed the batch-work data. Pregnant liquors contain only about 47 milligrams per liter of uranium. Those were processed by liquid-liquid extraction using 0.05 moles of 6-benzylamino-3,9-diethyltridecane in kerosene. This solvent shows low distribution coefficients for contaminant ions and a very high distrioution coefficient for uranium. Consequently it was possible to recover uranium at high aqueous to organic flow ratios. This combined with a high organic to aqueous flow ratio in sodium carbonate stripping made it possible to produce loaded strip solutious containing more than 18 grams per liter of uranium despite the low level uranium in the feed. Chlorination at temperatures in the range of 500 to 800 deg C with both retorted and roasted shale using a variety of chlorliating agents was investigated Roasted shale required carbon in the chlorinating -agent and was capable of 85% volatilization of uranium but required one to three hours. Retorted shale reached the same level of recovery in 15 seconds. Iron and aluminum and considerable quantitles of potassium were also volatilized. Whereas steady state chloride product streams were produced no steady state recovery system was developed. Such a system based on the passage of the chloride product stream through hot packed columns containing KCl/sub 3/-- AlCl/sub 3/ mixtures resulted in good uranium retention However, the columns were difficult to control and unstable. (auth)
- Research Organization:
- Columbia Univ., New York. Mineral Beneficiation Lab.
- NSA Number:
- NSA-12-014702
- OSTI ID:
- 4328254
- Report Number(s):
- A/CONF.15/P/1024
- Resource Relation:
- Other Information: Prepared for the Second U.N. International Conference on the Peaceful Uses of Atomic Energy, 1958. Orig. Receipt Date: 31-DEC-58
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
ALKANES
AMINES
CARBON
CHATTANOOGA
CHLORINATION
CLAYS
CONCENTRATION
COUNTER CURRENT
DISTRIBUTION
EFFICIENCY
ETHYL RADICALS
EVAPORATION
GASES
GRAIN SIZE
HEATING
HIGH TEMPERATURE
HYDROCARBONS
IMPURITIES
IONS
KEROSENE
LEACHING
LIQUIDS
OPERATION
ORE PROCESSING
OXYGEN
PETROLEUM
PRESSURE
PYROLYSIS
QUANTITY RATIO
RECOVERY
ROCKS
SEPARATION PROCESSES
SHALES
SODIUM CARBONATES
SOLIDS
SOLUTIONS
SOLVENT EXTRACTION
SOLVENTS
SULFURIC ACID
TEMPERATURE
TESTING
TOLUENE
URANIUM
URANIUM COMPOUNDS
URANIUM ORES
WATER