Studies on the stability of bitumen salt mixtures. Pt. 3

In connection with the embedding of low- to intermediate active waste, coming from reprocessing plants, into bitumen further studies have been undertaken in continuation of already published tests using samples consisting of bitumen and simulated steel corrosion products. To get these, high-quality steels have been submitted to a leaching with nitric acid. The acidic solutions have been evaporated to dryness and embedded into bitumen. The thermogravimetric measurements have been carried out in air and saturated water vapour. It could be shown that, at the embedding temperatures between 1800C and 2500C, weight losses in air or water vapour resulting out of thermic stress are negligible if the embedded salt concentrate has been adjusted to a pH of 9 to 10 prior to the evaporation. (orig.)