Ion Chromatography (IC) Analysis of Glycolate in Simulated Waste

White, T.L.; Zamecnik, J.R.; Riley, W. T.

doi:10.2172/1182713

“… Testing with actual waste confirmed that the Caustic Quench method previously developed [7] should be used for anion measurement by IC for SRAT and SME product slurries and SRAT receipt slurry. 2 No No No No No No No No No No…”

Section: Recommendationsmentioning

confidence: 81%

“…The CQ method was developed as an IC preparation for acidic slurries to stop oxidation reactions, to free up chelated organic acids by converting chelated metal compounds to metal oxides, and to adjust the pH of the sample to match the IC eluent. The CQ preparation and analysis were performed as described in the test report [7]. In the CQ method, ~2 g of 50 wt% NaOH solution was mixed with ~10 g of slurry followed by dilution of a 1 mL aliquot of the CQ mixture to 100 mL with de-ionized water and filtration of the diluted mixtures.…”

Section: Anions In the Slurrymentioning

confidence: 99%

“…The DWPF should continue with its plans to use its method for sample preparation to support mercury process control analyses. A method of analysis of glycolic acid by IC was developed in support of the alternate reductant flowsheet [7]. Comparisons of the CQ method and water dilution methods are presented below.…”

Section: Srnl-sti-2016-00327 Revisionmentioning

confidence: 99%

“…The CQ preparation method was previously recommended as the preferred method for acidic slurry IC anions measurements for the SRAT and SME product with the nitric-glycolic acid flowsheet [7]. During the method development work, the CQ method was shown to provide higher results for glycolate than water dilution results that were known to be biased low.…”

Section: Srnl-sti-2016-00327 Revisionmentioning

confidence: 99%

See 2 more Smart Citations

Actual waste demonstration of the nitric-glycolic flowsheet for sludge batch 9 qualification

Newell

¹

,

Pareizs

²

,

Martino

³

et al. 2017

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For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs qualification testing to demonstrate that the sludge batch is processable. Testing performed by the Savannah River National Laboratory has shown glycolic acid to be effective in replacing the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the catalytic generation of hydrogen and ammonia which could allow purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective rheology adjustment, and is favorable with respect to melter flammability. In order to implement the new flowsheet, SRAT and SME cycles, designated SC-18, were performed using a Sludge Batch (SB) 9 slurry blended from SB8 Tank 40H and Tank 51H samples. The SRAT cycle involved adding nitric and glycolic acids to the sludge, refluxing to steam strip mercury, and dewatering to a targeted solids concentration. Data collected during the SRAT cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. The SME cycle demonstrated the addition of glass frit and the replication of six canister decontamination additions. The demonstration concluded with dewatering to a targeted solids concentration. Data collected during the SME cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. Slurry and condensate samples were collected for subsequent analysis. Chemical Process Cell (CPC) demonstrations utilizing the alternate reductant flowsheet were performed at an acid stoichiometry of 78.0% Koopman Minimum Acid basis (87.1% Hsu basis) for the SRAT cycle. The scope specified by the technical task request has been successfully completed. Highlights of the testing results are summarized in the paragraphs below. The total solids measurements of the SRAT and SME products were 24.6 and 49.0 weight percent (wt%), respectively, which matched the targets of 25 wt% and 48 wt% acceptably. The consistency and yield stress of the SRAT receipt material fall within the DWPF design basis. The SRAT product yield stress and consistency (0 Pa and 2.8 cP, respectively) are below the DWPF design basis. The SME product yield stress and consistency were 1.0 Pa and 16.0 cP, respectively. The SME product yield stress is below the DWPF design basis. It should be noted that similar rheological properties were encountered during SB5 processing at DWPF. DWPF successfully processed SB5 by implementing process control software to mitigate issues related to the melter feed. This software is still in use at DWPF. Based on the comparison of the iron in the SRAT product and SME product analyses, the waste loading of the SME product is 37.6%. The current DWPF target for waste loading is 36%. Calculations based on several of the other major sludge components (Al, Ca, Mn, Ni, and U) indicated waste loadings ranging from 36....

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“…• Testing with actual waste confirmed that the Caustic Quench method previously developed [7] should be used for anion measurement by IC for SRAT and SME product slurries and SRAT receipt slurry. 6 No No No No No No No No No No .07 No No No No No No No No No No No 9 1 No No No No No No No No No No No .022 No No No No No No No No No No No 2 No No No No No No No No No No .08 No No No No No No No No No No No 12 14 No No No No No No No No No No No .08 No No No No No No No No No No No .035 No No No No No No No No No No No .045 No No No No No No No No No No No 2 No No No No No No No No No No 5 5 No No No No No No No No No No No 2 No No No No No No No No No No No 22 No No No No No No No No No No No .025 No No No No No No No No No No 7 No No No No No No No No No No No 5 3 No No No No No No No No No No .03 No No No No No No No No No No No…”

Section: Recommendationsunclassified

Actual Waste Demonstration of the Nitric-Glycolic Flowsheet for Sludge Batch 9 Qualification

D.¹,

Pareizs

²

,

Martino

³

et al. 2016

0

View full text Add to dashboard Cite

For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs qualification testing to demonstrate that the sludge batch is processable. Testing performed by the Savannah River National Laboratory has shown glycolic acid to be effective in replacing the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the catalytic generation of hydrogen and ammonia which could allow purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective rheology adjustment, and is favorable with respect to melter flammability. In order to implement the new flowsheet, SRAT and SME cycles, designated SC-18, were performed using a Sludge Batch (SB) 9 slurry blended from SB8 Tank 40H and Tank 51H samples. The SRAT cycle involved adding nitric and glycolic acids to the sludge, refluxing to steam strip mercury, and dewatering to a targeted solids concentration. Data collected during the SRAT cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. The SME cycle demonstrated the addition of glass frit and the replication of six canister decontamination additions. The demonstration concluded with dewatering to a targeted solids concentration. Data collected during the SME cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. Slurry and condensate samples were collected for subsequent analysis. Chemical Process Cell (CPC) demonstrations utilizing the alternate reductant flowsheet were performed at an acid stoichiometry of 78.0% Koopman Minimum Acid basis (87.1% Hsu basis) for the SRAT cycle. The scope specified by the technical task request has been successfully completed. Highlights of the testing results are summarized in the paragraphs below. The total solids measurements of the SRAT and SME products were 24.6 and 49.0 weight percent (wt%), respectively, which matched the targets of 25 wt% and 48 wt% acceptably. The consistency and yield stress of the SRAT receipt material fall within the DWPF design basis. The SRAT product yield stress and consistency (0 Pa and 2.8 cP, respectively) are below the DWPF design basis. The SME product yield stress and consistency were 1.0 Pa and 16.0 cP, respectively. The SME product yield stress is below the DWPF design basis. It should be noted that similar rheological properties were encountered during SB5 processing at DWPF. DWPF successfully processed SB5 by implementing process control software to mitigate issues related to the melter feed. This software is still in use at DWPF. Based on the comparison of the iron in the SRAT product and SME product analyses, the waste loading of the SME product is 37.6%. The current DWPF target for waste loading is 36%. Calculations based on several of the other major sludge components (Al, Ca, Mn, Ni, and U) indicated waste loadings ranging from 36....

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Flowsheet Testing for Strip Effluent to Slurry Mix Evaporator Modifications at the Defense Waste Processing Facility

Zamecnik¹

2015

Self Cite

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Savannah River Remediation plans to add strip effluent to the Sludge Receipt and Adjustment Tank (SRAT) and/or the Slurry Mix Evaporator (SME) during processing in the Defense Waste Processing Facility (DWPF). At the present time, strip effluent is added only to the SRAT, but this flowsheet change is planned to allow more flexibility in processing the large volume of strip effluent produced by the Modular Caustic-side Solvent Extractant Unit (MCU) or the Salt Waste Processing Facility (SWPF).Four process demonstrations of the coupled flowsheet for SRAT and SME cycles were performed using SB8-Tank 40 simulant. These runs were patterned after run SB8-D5 (a previous coupled experiment completed in developing the SB8 flowsheet and utilizing the same sludge simulant, addition of Actinide Removal Product (ARP), and acid addition). Differences from run SB8-D5 included much higher noble metal concentrations and very long strip effluent addition times (equivalent to 38,000 gallons of Strip Effluent, including 30,000 gallons of Strip Effluent added to the SME), which combined to make this a very challenging set of runs.The main difference between the runs was that three strip effluent combinations (original solvent based on BobCalix/nitric acid, new solvent based on MaxCalix/boric acid, and a blend of the two) were used. A fourth run was performed without solvent and using water as the strip effluent solution to see whether the solvent or strip effluent acid had any impact on processing, particularly hydrogen generation.Although allowing a large addition of strip effluent to either the SRAT or SME offers obvious operational advantages, it also requires a longer time at temperature than typical DWPF batches, which may lead to higher hydrogen generation, higher ammonia production, higher formate destruction, lower Reduction/Oxidation (REDOX) Ratio, higher potential for foaming and coil fouling, and higher yield stress and consistency. Although these impacts could be carefully controlled, consistent processing (same sludge, ARP, strip effluent, and decon water volume for each SRAT and SME batch), should lead to consistent product chemistry. Processing at the maximum volumes of strip effluent, whether in the SRAT, SME or both increases the likelihood of the process problems listed above and may require remediation of the SME product with nitric or formic acid to achieve the desired glass REDOX. Due to the high pH of the SME product leading to higher yield stress and consistency, the melter feed pump may have more difficulty feeding to the melter without dilution. Some of the highlights of the testing are summarized below:• The destruction of formate was very high in all runs, but especially high in the two runs with the highest hydrogen generation. The SME formate destruction varied from 29.3 to 70.7% for the four runs, much higher than the 2% measured in a similar run during SB8 blend qualification. This led to a high generation of CO 2 , which could increase the potential for foamovers. • Due to the high anion destruction ra...

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Ion Chromatography (IC) Analysis of Glycolate in Simulated Waste

Cited by 10 publications

References 4 publications

Actual waste demonstration of the nitric-glycolic flowsheet for sludge batch 9 qualification

Actual waste demonstration of the nitric-glycolic flowsheet for sludge batch 9 qualification

Actual Waste Demonstration of the Nitric-Glycolic Flowsheet for Sludge Batch 9 Qualification

Flowsheet Testing for Strip Effluent to Slurry Mix Evaporator Modifications at the Defense Waste Processing Facility

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