Laboratory Scale Antifoam Studies for the STTPB Process

Baich, M.A.

Savannah River Site (S.C.)

关键词: Radioactive Waste Processing;    Air;    Washing;    Mitigation;    Entrainment;   

DOI  :  10.2172/774860
RP-ID  :  WSRC-TR-2000-00261
RP-ID  :  AC09-96SR18500
RP-ID  :  774860

美国|英语

来源: UNT Digital Library

【 摘 要 】

Three candidate antifoam/defoam agents were tested on a laboratory scale with simulated KTPB slurry using the proposed STTPB process precipitation, concentration, and washing steps. Conclusions are if air entrainment in the slurry is carefully avoided, little or no foam will be generated during normal operations during precipitation, concentration, and washing of the precipitate. Three candidate antifoam/defoam agents were tested on a laboratory scale with simulated KTPB slurry using the proposed STTPB process precipitation, concentration and washing steps. In all cases little or no foam formed during normal operations of precipitation, concentration and washing. Foam was produced by purposely-introducing gas sub-surface into the slurry. Once produced, the IIT B52 antifoam was effective in defoaming the slurry. In separate foam column tests, all antifoam/defoam agents were effective in mitigating foam formation and in defoaming a foamed 10 wt % insoluble solids slurry. Based on the results in this report as well as foam column studies at IIT, it is recommended that IIT B52 antifoam at the 1000 ppmV level be used in subsequent STTPB work where foaming is a concern. This study indicates that the addition of antifoam agent hinders the recovery of NaTPB during washing. Washing precipitate with no antifoam agent added had the highest level of NaTPB recovery, but had the shortest overall washing time ({approximately}19 hours) compared to 26-28 hours for antifoam runs. The solubilities of the three candidate antifoam/defoam agents were measured in a 4.7 M sodium salt solution. The Surfynol DF-110D defoamer was essentially insoluble while the two IIT antifoamers; Particle Modifier (PM) and B52 were soluble to at least the 2000 ppmV level.