Recovery anode residue

The anode residues must be chemically processed to recover the plutonium remaining in the residues. This may amount to about 10% of the feed mass if delta alloy is the feed metal. Either aqueous or pyrochemical processes may be used for anode recovery. One pyrochemical process used for recovery utilizes oxidation of the plutonium with zinc chloride to form plutonium chloride salt, followed by calcium reduction of the PUCI3 contained in the salt phase to produce pure plutonium metal (the impurities follow the zinc metal obtained from the oxidation reaction and are discarded to waste). Impurities more stable than calcium chloride remain in the salt phase and are also... 

Anode Residue Recovery. Approximately 10% of the plutonium present in a Pu- lwt% Ga electrorefining feed, ends up in the anode residue. This residue also contains most of the impurities which were present in the metal feed. The following pyrochemical processes have been considered for recovering plutonium from this residue. 

After a study of the three alternatives we concluded that pyroredox offered the most promise for anode residue recovery. Pyroredox is a molten-salt process in which plutonium metal is oxidized chemically into the salt phase and then reduced chemically into the metal phase. Most of the impurities are not oxidized and remain in the metal residue. Thus, for a Pu-Ga anode residual, the reactions would be ... 

Production of finished aluminum products by industrial facilities typically results in the generation of very large amounts of solid aluminum hydroxide anodizing residues (Saunders 1988). These aluminumanodizing residues are currently classified as nonhazardous under the Federal Resource Conservation and Recovery Act (RCRA) regulations. These residues are typically dewatered to reduce the volume of waste prior to being landfilled. However, the heavy metal content of these solid waste residues can be of... 

This is used in the secondary recovery of copper from anode slimes arising from copper refining copper is dissolved leaving a residue rich in selenium, tellurium and precious metals [373]. 

For cathode modification obtained results have shown that cell resistance is lower when electrodes are in contact with soil sample, and this allowed for higher hydrocarbon mobility, so residual concentration profile exhibits an increasing trend from anode to cathode. Otherwise, physical barrier inclusion increased soil resistance and so far, hydrocarbon mobility is lowered, this fact resulted in a decreasing concentration trend from anode to cathode. From oil and grease extractions it was determined that CF provides higher hydrocarbon removal, although this option is not the best because transported hydrocarbons get adsorbed in the electrode, being difficult its recovery. 

In all commercial fuel cells, provision must be made for residual fuel effluent recovery. Fuel utilization is not 100% due to concentration polarization limitation on performance discussed in Chapters 3 and 4, so that unused fuel in the anode exhaust stream is always present and must be actively recycled, utilized, or converted prior to exhaust to the environment. Potential effluent management schemes include the use of recycling pumps, condensers (for Uquid fuel), secondary burners, catalytic converters, or dead-end anode designs. 

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