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Title: Method for solidifying aqueous radioactive wastes for non-contaminating storage

Patent ·
OSTI ID:5994406

Method for solidifying high and medium radioactivity and/or actinide containing aqueous waste concentrates or fine-grained solid wastes suspended in water for final noncontaminating storage. The waste concentrates or suspensions are set, by evaporation, to a water content in the range between 40 and 80 percent by weight, and a solid content whose metal ion and/or metal oxide component lies between 10 and 30 percent by weight of the evaporate being formed. The ph of the evaporate is set to between 5 and 10. The evaporate is kneaded with a clay-like substance containing a small quantity of cement or such a claylike substance or mixture of a clay-like substance with a small quantity of cement containing an additive for suppressing the volatility of the alkalis or alkali earths and/or an additive for suppressing the volatility of any decomposing anions which may be present in the evaporate from the group including sulfate, phosphate, molybdate and uranate ions. The kneading occurs at a weight ratio range of evaporate to clay-like substance of 1:1 to 2:1. Molded bodies are produced from the resulting kneaded mass the molded bodies are then heat treated including drying at temperatures between room temperature and about 150/sup 0/C., calcining at temperatures up to about 800/sup 0/C and subsequently firing at temperatures between 800/sup 0/C. And 1400/sup 0/C to form practically undissolvable mineral phases. The molded bodies of fired mineral phases are enclosed on all sides in a dense, continuous ceramic or metallic matrix.

Assignee:
Kernforschungszentrum Karlsruhe Gmbh (Germany, Federal Republic Of)
Patent Number(s):
US 4297304
OSTI ID:
5994406
Resource Relation:
Patent Priority Date: Priority date 10 Jun 1977, German, Federal Republic of (F.R. Germany)
Country of Publication:
United States
Language:
English