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Title: Method and apparatus for reconditioning waste solutions of the nuclear industry which contain ammonium nitrate

Patent ·
OSTI ID:5976257

A method and apparatus are described for reconditioning waste solutions of the nuclear industry which contain ammonium nitrate. The waste solution is continuously sprayed from above into a 300/sup 0/ to 600/sup 0/C hot zone, from the lower end of which the decomposition products are withdrawn and are separated into condensate and exhaust gas. The NO content is reduced by adding oxygen, especially at the exit of the decomposition zone. By the presence of reducing agents, such as CO(NH2)2 or preferably NH3, in the solution to be sprayed, the NO2 content of the decomposition products and the NH4NO3 residue in the condensate can be practically eliminated and an additional precipitation in the condensate which can be filtered off can be obtained. Optimal contents are 0.25-0.4 mol NH3 and 0.15-0.25 mol CO(NH2)2 per mol NH4NO3. Prior to the thermal decomposition, the waste solution is preferably concentrated, cooled off, and filtered to about 60% or (if a solution containing reducing agents is to be sprayed) about 48% NH4NO3 at about 60/sup 0/C. In a thin layer evaporator, and temporarily stored at room temperature. The addition of ammonia to the concentrate offers a precipitation which can be filtered off.

Assignee:
Kernforschungsanlage Julich Gmbh (Germany, Federal Republic Of)
Patent Number(s):
US 4285830
OSTI ID:
5976257
Resource Relation:
Patent Priority Date: Priority date 30 Nov 1977, German, Federal Republic of (F.R. Germany)
Country of Publication:
United States
Language:
English