Dennis F. Bickford

Vitrification of cesium-laden organic ion-exchange resin in a stirred melter

Tests were conducted using a stirred-tank melter to vitrify nonradioactive, cesium-laden organic ion-exchange resin. This resin, which is highly effective in removing cesium from solution, was developed to replace the complex sodium tetraphenylborate precipitation process used at the Defense Waste Processing Facility at the Savannah River Site to remove {sup 137}Cs from a wastewater solution. The glass produced had a Fe{sup 2+}/Fe{sup Total} ratio that was acceptable for high-level waste glass. No damage to the melter was observed. Lower-bound estimates of overall cesium retention in the glass range from 70.5 to 73.9%. Only 2.1 to 4.3% of the cesium was emitted from the melter. Because between 21.8 and 27.4% of the cesium was not recovered, the overall cesium retention may have been substantially higher.

Metal Emissions from Joule-Heated Vitrification Systems

Vitrification demonstrations were conducted for surrogates of three inorganic wastewater sludges in a high-temperature, refractory-lined, slurry-fed melter. The total par-ticulate concentrations and melter decontamination factors were determined for selected elements. The decontamination factors were less than 10 for cadmium and lead in all three demonstrations. The decontamination factors for chromium were less than 30 in the two demonstrations using refractories containing chromium, and they were greater than 150 for the demonstrations using refractories without chromium. Except for one demonstration on a surrogate waste with a high sulfate content, decontamination factors were above 80 for the other heavy metals in the demonstrations.

Vitrification of Cesium-Laden Organic Ion Exchange Resin in a Stirred Melter

The goal of this research was a feasibility study for vitrifying the organic ion exchange resin in a stirred-tank melter. Tests were conducted to determine the fate of cesium including the feed, exit glass, and offgas streams and to assess any impact of feeding the resin on the melter or its performance.