Testing was completed to demonstrate the viability of the newly developed glycolic /nitric flowsheet for processing in the Defense Waste Processing Facility ' s (DWPF) Chemical Process Cell (CPC). The Savannah River National Laboratory (SRNL) initiated a sludge matrix study to evaluate the impact on CPC processing. Four sludge simulants were designed to cover a broad insoluble solid composition range to bracket future sludge batches. The first pair of sludge parameters was high iron/low aluminum versus low iron/high aluminum (referred to as HiFe or LoFe in this report). The second pair of sludge parameters was high calcium-manganese/low nickel , chromium , and magnesium versus low calcium-manganese/high nickel , chromium, and magnesium (referred to as HiMn or LoMn in this report). In addition , a simple supernate simulant was prepared to match the composition of the matrix simulants. Ten experiments (GF34 to GF37 and GF34b, GF34c, GF36b, GF36c, GF37b and GF38) were completed to demonstrate the glycolic-nitric flowsheet viability using the sludge matrix simulants at a nominal lM Na washing endpoint. In addition, two experiments were performed with less washed simulants (GF40, 1.6 M Na and GF41, 1.9 M Na endpoints) to demonstrate the viability of processing these sludges. Five supernate experiments (GF39a-GF39e) were performed to better understand the reaction sequence, particularly the reduction and stripping of mercury. Composition and physical property measurements were made on the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) products. Composition measurements were made on the composited condensates from the Mercury Water Wash Tank (MWWT), and Formic Acid Vent Condenser (FAVC), on the ammonia scrubber solution, and on SRAT samples pulled throughout the SRAT cycle. Updated values for glycolate and formate loss, nitrite-to-nitrate conversion, and oxalate formation were found that can be used in the acid calculations for future process simulations with the glycolic-nitric flowsheet. Preliminary results of the initial testing indicate: • Hydrogen generation rate was below detection limits (<1.4E-3 lb/hr) DWPF-scale or <0.005 vol%) throughout all SRAT cycles with matrix simulants. Hydrogen generation rate was above detection limits for the less washed simulants (3.2E-3 lb/hr DWPF-scale or 0.009 vol%) due to the higher acid stoichiometry and the lower offgas purge. • Hydrogen generation rate was below 0.0258 lb/hr DWPF-scale (11.6% of DWPF SME limit) throughout all SME cycles with matrix simulants. The small amount of generated hydrogen with the nominal washing endpoint is attributed to formic acid added with the frit. When formic acid was not added with the frit in the underwashed sludge runs (GF40 and GF41), the maximum hydrogen seen was 1.8E-3 lb/hr DWPF scale (0.81% of DWPF SME limit). • Mercury was both reduced and stripped without formic acid. The mercury concentration of the SRAT product was below the 0.8 wt % target in eight of the runs and below 0.92 wt %in the other four runs. • ...
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