PROPERTIES OF DEGRADED TBP-AMSCO SOLUTIONS AND ALTERNATIVE EXTRACTANT- DILUENT SYSTEM
The formation and chemical properties of the major degradation products of several diluents in contact with acidic nitrate solutions were studied, together with (1) methods for purifying degraded solvent, (2) methods of pretreating the solvent to minimize degradation, and (3) the relative stability of several solvent systems. Emphasis was on Amsco 125-52, a specially treated naphtha used extensively at ORNL in radiochemical processing. Degradation of the diluent, usually containing 1M TBP, was induced by boiling with HNO/sub 3/ or by irradiating (Co/sub 60/ gamma ) while agitating the solvent phase with HNO/sub 3/. Nitroparaffins, RNO/sub 2/, were the major degradation products and were formed at twice the rate when TBP was present during degradation. Under the conditions of degradation 100 watt-hr/liter exposure was essentially equivalent to 11 hr boiling with 2M HNO/sub 3/ as shown by Zr- Nb extraction, total organic nitrogen analysis, and spectrophotometric analysis. Extraction from acid solution of certain fission products, e.g., Zr- Nb but not Ru, increased markedly after the degraded solvent was treated with alkaline reagents, and a test employing solid calcium hydroxide wvas developed to estimate the extent of diluent degradation. The alkaline treatment converted a significant fraction of the nitroparaffin to the enol form. There was synergistic extraction of Zr- Nb by the combination of TBP and degraded diluent. Cleanup of the degraded solvents can be attained by scrubbing with alkanolamines to remove nitroparaffin-amine salts or by contacting with activated alumina. Both methods have doubtful economic and the latter requires solids handling. Low pressure flash distillation is an effective, inexpensive method for partial or total repurification of degraded TBP-Amsco. With aliphatic diluents the configuration most stable against nitration is the simplest, e.g.. n-dodecane. Pretreating Amsco 125-82 by scrubbing with concentrated sulfuric acid before degrading with hot nitric acid improved its stability. Aromatic diluents increase the radiation stability and extraction selectivity of TBP. The stabilities of the simple alkylbenzenes against nitration vary widely with the number of alkyl groups, their type, and their position, but a mixture of diethylbenzenes low in the para isomer and some of the polymethylbenzenes did not form fission product extractants in routine tests. Nitration of the benzene ring does not produce Zr- Nb extractants. 72 references. (auth)
- Research Organization:
- Oak Ridge National Lab., Tenn.
- NSA Number:
- NSA-18-006899
- OSTI ID:
- 4125007
- Journal Information:
- Nuclear Science and Engineering (U.S.), Journal Name: Nuclear Science and Engineering (U.S.) Vol. Vol: 17; ISSN NSENA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
ADSORPTION
ALCOHOLS
ALKANES
ALKYL RADICALS
ALUMINUM OXIDES
AMINES
AMSCO
AROMATICS
ARYL RADICALS
BENZENE
BIBLIOGRAPHY
BOILING
BUTYL PHOSPHATES
CALCIUM HYDROXIDES
CHEMICAL REACTIONS
CHEMICALS
CHEMISTRY
COBALT 60
CONFIGURATION
DECOMPOSITION
DISTILLATION
DODECANE
ECONOMICS
EFFICIENCY
ETHYL RADICALS
EXTRACTION COLUMNS
FISSION PRODUCTS
GAMMA RADIATION
GAMMA SOURCES
HIGH TEMPERATURE
HYDROCARBONS
IMPURITIES
IRRADIATION
ISOMERS
KEROSENE
KETONES
MEASURED VALUES
MIXING
MOLECULES
NIOBIUM
NIOBIUM COMPLEXES
NIOBIUM NITRATES
NITRATES
NITRIC ACID
NITROBENZENE
OPERATION
ORGANIC NITROGEN COMPOUNDS
PARAFFIN
PERFORMA