SciTech Connect

Title: Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin

Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin The 177 underground storage tanks at the DOE`s Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. CS-100 shows the presence of phenoxy-ether groups, and this may account for the much lower decontamination factor of CS-100 for cesium ion. Curing temperatures for the R-F resin were found to be optimal at 105--130C. At lower temperatures, insufficient curing, hence crosslinking, of the polymer resin occurs and selectivity for cesium drops. Curing at elevated temperatures leads to chemical degradation. Optimal more » particle size for R-F resin is in the range of 20--50 mesh-sized particles. R-F resin undergoes chemical degradation or oxidation which destroys ion-exchange sites. The ion-exchange sites (hydroxyl groups) are converted to quinones and ketones. CS-100, though it has much lower performance for cesium ion-exchange, is significantly more chemically stable than R-F resin. To gamma radiation, CS-100 is more radiolytically stable than R-F resin. « less
Authors: ; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:110245
Report Number(s):PNL--10744
ON: DE96000200; TRN: 95:022090
DOE Contract Number:AC06-76RL01830
Resource Type:Technical Report
Data Type:
Resource Relation:Other Information: PBD: Aug 1995
Research Org:Pacific Northwest Lab., Richland, WA (United States)
Sponsoring Org:USDOE, Washington, DC (United States)
Country of Publication:United States
Language:English
Subject: 05 NUCLEAR FUELS; 40 CHEMISTRY; ORGANIC ION EXCHANGERS; PERFORMANCE; COMPARATIVE EVALUATIONS; CESIUM; ION EXCHANGE; RADIOACTIVE WASTE FACILITIES; REMEDIAL ACTION; RADIOACTIVE WASTE PROCESSING; RESINS; RESORCINOL; FORMALDEHYDE; TANKS