Recovery of silver from CEPOD anolyte solutions
- Pacific Northwest Lab., Richland, WA (United States)
- EG&G Rocky Flats Plant, Golden, CO (United States)
The process known as Catalyzed Electrochemical Plutonium Oxide Dissolution (CEPOD) has been shown effective for removing plutonium from a variety of residues and solids. This process involves the electrochemical oxidation of PuO{sub 2} (and other Pu species) to (PuO{sub 2}){sup 2+}, and dissolution of the latter species in the anode solution (anolyte). Silver is used to transfer charge from the electrodes to the solid Pu oxide. Ag (1) is oxidized at the anode to Ag(II) and carried by the solution to the plutonium oxide solids, where the silver and oxide undergo a redox reaction that converts Pu(IV) to Pu(VI), and Ag(II) to Ag(I). Other metal ions [such as Ce(IV) and Co(III)] may also be used for this charge transfer, but have been found to be less effective than silver. The same process may be used to destroy various organic materials (such as paper and wood, oil and fuels, and synthetic polymer materials) by complete oxidation to CO{sub 2} or H{sub 2}O, for example. Upon completion of a CEPOD dissolver run, the anolyte may be processed to remove solution species of interest (i.e., Pu), or the anolyte may be recycled, or disposed. Because silver is a Resource Conservation and Recovery Act (RCRA) land ban material, it must be removed from waste streams. Preliminary experiments, completed in FY 1991, demonstrated a simple, effective technique for silver removal from solutions. Ascorbic acid (C{sub 6}H{sub 8}O{sub 6}) Was Used to reduce silver ion to metallic silver, which precipitates from solution. The process was demonstrated effective on a bench scale using samples of actual CEPOD anolyte. Further experiments, in FY 1993, optimized these parameters and demonstrated the effectiveness of the technique on CEPOD anolyte on a larger, process scale (liters of solution). This report describes both the preliminary bench-scale experiments and the more recent process-scale experiments. The results are also compared to electro-deposition, another method of silver ion removal.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 10186420
- Report Number(s):
- PNL--10164; ON: DE95000831
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electrochemical process for dissolving plutonium dioxide and leaching plutonium from scrap or wastes
Catalyzed Electrolytic Plutonium Oxide Dissolution (CEPOD): The past seventeen years and future potential
Electrochemical process for dissolving plutonium dioxide and leaching plutonium from scrap or wastes
Conference
·
Tue Dec 31 23:00:00 EST 1985
·
OSTI ID:6530050
Catalyzed Electrolytic Plutonium Oxide Dissolution (CEPOD): The past seventeen years and future potential
Conference
·
Sun Jul 01 00:00:00 EDT 1990
·
OSTI ID:6496239
Electrochemical process for dissolving plutonium dioxide and leaching plutonium from scrap or wastes
Conference
·
Fri Oct 31 23:00:00 EST 1986
·
OSTI ID:7229226