Isolation of Metals from Liquid Wastes: Reactive Scavenging in Turbulent Thermal Reactors

Technical Report · Thu Dec 16 00:00:00 EST 2004

DOI:https://doi.org/10.2172/835123· OSTI ID:835123

Linak, William

Sorption of cesium and strontium on kaolinite powders was investigated as a means to minimize the emissions of these metals during certain high temperature processes currently being developed to isolate and dispose of radiological and mixed wastes. In this work, non-radioactive aqueous cesium acetate or strontium acetate was atomized down the center of a natural gas flame supported on a variable-swirl burner in a refractory-lined laboratory-scale combustion facility. Kaolinite powder was injected at a post-flame location in the combustor. Cesium readily vaporizes in the high temperature regions of the combustor, but was reactively scavenged onto dispersed kaolinite. Global sorption mechanisms of cesium vapor on kaolinite were quantified, and are related to those available in the literature for sodium and lead. Both metal adsorption and substrate deactivation steps are important, and so there is an optimum temperature, between 1400 and 1500 K, at which maximum sorption occurs. The presence of chlorine inhibits cesium sorption. In contrast to cesium, and in the absence of chlorine, strontium was only partially vaporized and was, therefore, only partially scavengeable. The strontium data did not allow quantification of global kinetic mechanisms of interaction, although equilibrium arguments provided insight into the effects of chlorine on strontium sorption. These results have implications for the use of sorbents to control cesium and strontium emissions during high temperature waste processing including incineration and vitrification.

• Research Organization: U.S. Environmental Protection Agency (US)
• Sponsoring Organization: USDOE Office of Civilian Radioactive Waste Management (RW) (US)
• DOE Contract Number: AI07-97ER14839
• OSTI ID: 835123
• Report Number(s): DOE/ER/14839; EPA-DW89938469-01; TRN: US0500153
• Resource Relation: Other Information: PBD: 16 Dec 2004
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
ACETATES
ADSORPTION
CESIUM
CHLORINE
COMBUSTION
DEACTIVATION
KAOLINITE
KINETICS
LIQUID WASTES
NATURAL GAS
SCAVENGING
SODIUM
SORPTION
STRONTIUM
THERMAL REACTORS
VITRIFICATION
WASTE PROCESSING
CESIUM
STRONTIUM
KAOLINITE
SORPTION
RADIOACTIVE WASTE
MIXED WASTE
INCINERATION
VITRIFICATION