Salt disposition alternatives filtration at SRTC

Walker, B. W. ; Hobbs, D.

Savannah River Site (S.C.)

关键词: Evaporators;    Removal;    Filtration;    Sludges;    Actinides;   

DOI  :  10.2172/750902
RP-ID  :  WSRC-TR-98-00364
RP-ID  :  AC09-96SR18500
RP-ID  :  750902

美国|英语

来源: UNT Digital Library

【 摘 要 】

Several of the prospective salt disposition alternative technologies require a monosodium titanate (MST) contact to remove strontium and actinides from inorganic salt solution feedstock. This feedstock also contains sludge solids from waste removal operations and may contain defoamers added in the evaporator systems. Filtration is required to remove the sludge and MST solids before sending the salt solution for further processing. This report describes testing performed using the Parallel Theological Experimental Filter (PREF). The PREF contains two single tube Mott sintered metal crossflow filters. For this test one filter was isolated so that the maximum velocities could be achieved. Previous studies showed slurries of MST and sludge in the presence of sodium tetraphenylborate (NaTPB) were filterable since the NaTPB slurry formed a filter cake which aided in removing the smaller MST and sludge particles. Some of the salt disposition alternative technologies do not use NaTPB raising the question of how effective crossflow filtration is with a feed stream containing only sludge and MST. Variables investigated included axial velocity, transmembrane pressure, defoamer effects, and solids concentration (MST and sludge). Details of the tests are outlined in the technical report WSRC-RP-98-O0691. Key conclusions from this study are: (1) Severe fouling of the Mott sintered metal filter did not occur with any of the solutions filtered. (2) The highest fluxes, in the range of .46 to 1.02 gpm/f{sup 2}, were obtained when salt solution decanted from settled solids was fed to the filter. These fluxes would achieve 92 to 204 gpm filtrate production for the current ITP filters. The filtrate fluxes were close to the flux of 0.42 gpm/f{sup 2} reported for In Tank Precipitation Salt Solution by Morrisey. (3) For the range of solids loading studied, the filter flux ranged from .04 to .17 gpm/f{sup 2} which would result in a filtrate production rate of 9 to 31 gpm for the current HP filter. (4) Filtrate flux for slurries containing solids and defoamers was between the range of .04 to .13 gpm/f{sup 2} which is better than the average flux of 0.024 gpm/f{sup 2} reported for Late Wash. (5) Filtrate flux is weakly dependent on the variables of insoluble solids concentration, defoamer concentration, transmembrane pressure, axial velocity, and filtration time.