Sludge Batch 6/Tank 40 Simulant Chemical Process Cell Simulations

Abstract

Phase III simulant flowsheet testing was completed using the latest composition estimates for SB6/Tank 40 feed to DWPF. The goals of the testing were to determine reasonable operating conditions and assumptions for the startup of SB6 processing in the DWPF. Testing covered the region from 102-159% of the current DWPF stoichiometric acid equation.

Sludge Batch 7 Qualification and Flowsheet Chemical Process Cell Simulations

“…It is likely that the mercury either stuck to the inner surfaces of the apparatus, mostly in the SRAT/SME kettle, or it is possible that the mercury was reduced to the elemental form and remained as part of a heterogeneous, globular component in the SME product; this second possibility would also make sampling difficult because of the small likelihood of capturing a piece of isolated globules of mercury in the slurry, even under agitation. Unlike the Phase III SB6 high acid runs, 15 there was no visible deposition of mercury or mercury amalgams on the agitator shaft or blades.…”

“…There was a significant amount of ammonium and ammonia generated as the pH rose above neutral during the SRAT cycles, as was the case for SB6. 15 ' n Secondary peak production of hydrogen, C0 2 , and N 2 0 in the high acid runs of both flowsheet and qualification simulant seem to coincide around the same time, suggesting that a common reactant may be involved in the production of these gases. The production of ammonia and ammonium is likely related to these precursor gases and there is speculation from the SB6 Phase III study that a possible mechanism for producing ammonia would involve a catalyst of either Ru or a mercury amalgam; 15 there is no evidence here that would either support or discard these possibilities.…”

Sludge Batch 7 Qualification and Flowsheet Chemical Process Cell Simulations

“…There was a significant amount of ammonium and ammonia generated as the pH rose above neutral during the SRAT cycles, as was the case for SB6. 15,17 Secondary peak production of hydrogen, CO 2 , and N 2 O in the high acid runs of both flowsheet and qualification simulant seemed to coincide, suggesting that a common reactant was involved in the production of these gases. The production of ammonia and ammonium is likely related to these precursor gases and there is evidence from the SB6 Phase III study that a possible mechanism for producing ammonia would require a catalyst of either Ru or a mercury amalgam; 15 there is no evidence here that would argue against the proposed reaction model.…”