A Summary of Rheology Data For SB3 and SB2/3 Blend Simulant Savannah River Site Wastes

KOOPMAN, DAVIDC.

Savannah River Site (S.C.)

关键词: Evaporators;    Sludges;    Simulant;    Srat;    Targets;   

DOI  :  10.2172/828298
RP-ID  :  WSRC-TR-2004-00116
RP-ID  :  AC09-96SR18500
RP-ID  :  828298

美国|英语

来源: UNT Digital Library

【 摘 要 】

The purpose of this study was to document the rheological measurements made for Sludge Batch 3 (SB3) and the blend of SB3 with Sludge Batch 2 (SB2). These measurements were primarily made on Slurry Mix Evaporator (SME) products, i.e. melter feeds. Some measurements were made on SB2/3 blend Sludge Receipt and Adjustment Tank (SRAT) products. Measurements on radioactive SB3 and SB2/3 samples have been limited to sludge characterization. SB2/3 measurements studied the impact of changing the SRAT acid addition strategy on the SRAT and SME product rheology. SB2/3 measurements also studied the impact of changing the waste loading target (sludge oxides content in glass) of the SME product. SB3 measurements studied the impact of changes in the wash end point and acid addition strategy on the SME product (melter feed) rheology. A summary of the significant findings is given below: SB3 radioactive sludge and blended SB2/3 radioactive sludge were less viscous than SB2 radioactive sludge. SB2/3 b lend sludge is more viscous than SB3 sludge. SB3 simulant SME product rheology was strongly impacted by changing the noble metal concentrations to more closely match those of the qualification sample. This reduction in noble metals produced a lower pH product that was also considerably less viscous. Increased acid addition in the SB2/3 SRAT generally led to less viscous simulant SRAT products. This trend did not persist in the SME products. SME products became more viscous when increased acid was used in the SRAT cycle from 135 per cent up to 170 per cent of stoichiometry, then became less viscous as total acid was increased further to 185 per cent. A significant increase in hydrogen generation occurred between 170 per cent and 185 per cent. The impact of acid addition on SB3 SME products was also variable. The impact of waste loading changes from 31 to 35 to 40 per cent on SB2/3 simulant SME products led to more viscous melter feeds as waste loading increased at constant wt. per cent total solids.The slurry pH seemed to be having a significant effect on the rheological variations within a set of similar simulant samples. The most viscous slurry in a set often had an intermediate pH in the 5-8 range. Rheological differences were seen as a function of wash endpoint with simulants. The Case 7d SB2/3SME product was more viscous than the less-washed Case 6b SME product. The more-washed SB3 simulant SME products that started at 20,000 mg/kg sludge nitrite were more viscous than the less washed SB3 simulant SME products that started at 27,000 mg/kg sludge nitrite.