FRACTIONAL CRYSTALLIZATION OF HANFORD WASTE

Transcription

1 Engineering Solutions for a New Millennium An AREVA Group Company FRACTIONAL CRYSTALLIZATION OF HANFORD WASTE Don Geniesse, Presenter

2 INTRODUCTION HANFORD WASTE CONTAINS THE MAJORITY OF ELEMENTS, MANY ISOTOPES, AND SEVERAL OXIDATION STATES A TOTAL OF 1,600 ESP SPECIES FRACTIONAL CRYSTALLIZATION CAN SEPARATE COMMON SODIUM SALTS (NaNO 3, Na 2 SO 4, Na 2 CO 3 ) FROM THE BULK OF SOLUBLE RADIOACTIVE COMPONENTS (Cs, Tc, I) FOR LAW TREATMENT FRACTIONAL CRYSTALLIZATION FLOWSHEET MODELED & OPTIMIZIED USING ESP

3 WATER ANALYZER WATER ANALYZER USED TO RECONCILE ANALYTICAL DATA CHARGE BALANCE FREE HYDROXIDE BALANCE FOR ALUMINUM SOLUBILITY PHASE CONTACT STUDIES TO DETERMINE SOLIDS BASED ON SOLUBILITY (i.e. Fe(OH) 3, FeOOH, Fe 2 O 3 ) REDOX SURVEYS TO DETERMINE OXIDATION STATES (i.e. Cr, Mn, Hg, Co)

4 REDOX SURVEY AY102 REDOX SURVEY CONCENTRATION 1.00E E E E E E E E E E E E E E-10 ORP N(+2) N(+3) N(+5) PU(+4) PU(+5) PU(+6) HG(0) HG(+2) AG(0) AG(+3) MN(+2) MN3O4PPT MN(+3) MN(+4) MN(+6) MN(+7) CO(+2) CO3O4PPT CEO2PPT CE(+3)AQUE RHIIIOH2ION RH2O3PPT RH(+2)AQUE

5 EVAPORATION SURVEYS EVAPORATION SURVEYS GRAPH IONIC ACTIVITY DATA, SOLUBILITY PRODUCTS, IONIC STRENGTH, AND PRECIPITATION CURVES USED TO DETERMINE OPTIMUM CRYSTALLIZATION TEMPERATURE AND EXTENT OF EVAPORATION

6 EVAPORATION SURVEY CASE αna+ αso αco3-2 αno3-1 ln a or PRECIPITATED SOLIDS (gms) IONIC STRENGTH αoh-1 αal(oh)4-1 αh2o ҚNa6(SO4)2CO3 ҚNa2CO3.1H2O ҚNaNO3 ҚNaAlO2 ҚAl(OH)3 Na6(SO4)2CO3(s) Na2CO3.1H2O(s) NaNO3(s) Na2Al2O4.2½H2O(s) Al(OH)3(s) H2O EVAPORAT ED (gms) IONIC ST RENGT H

7 THREE DIMENSIONAL SURVEYS THREE-DIMENSIONAL SURVEYS ARE USED TO DETERMINE OPERATING LINE FOR CRYSTALLIZATION

8 kg SOLIDS/1000 kg WASTE kg H 2 O ADDED/1000 kg WASTE kg NaOH/1000 kg WASTE 55C Na2CO3 Al(OH)3 Na6(S O4)2CO3 FeO(OH) NaNO3

9 ALUMINUM SOLUBILITY MAINTAINING ALUMINUM SOLUBILITY IS VERY IMPORTANT DURING SALT CRYSTALLIZATION SLOW ALUMINUM CRYSTALLIZATION KINETICS ALUMINUM MAY FORM AMORPHOUS Al(OH) 3 GEL IF GIBBSITE SOLUBILITY IS EXCEEDED ALUMINUM SOLUBILITY CONTROLLED BY MAINTAINING IAP s OF Al(OH) 3 & NaAlO 2 EQUAL DURING CRYSTALLIZATION

10 GIBBSITE / SODIUM ALUMINATE SOLUBILITY C APPS 40C APPS ALUMINUM SOLUBILITY (mol/l) GIBBSITE Al(OH) 3 SODIUM ALUMINATE NaAlO H 2 O 60C APPS 80C APPS 90C APPS 25 ESP 40 ESP 60 ESP 80 ESP 95 ESP 25 ESP MIX 40 ESP MIX 60 ESP MIX 80 ESP MIX 95 ESP MIX Al(OH) FREE HYDRO XIDE CO NCENTRATIO N (mol/l)

11 ESP FLOWSHEET MODELING ESP FLOWSHEET MODELS ARE USED TO SIMULATE FRACTIONAL PROCESS TO DETERMINE: THEORETICAL CRYSTALLIZATION YIELDS MAXIMUM RECYCLE RATES EXTENT OF DECONTAMINATION

12 ONE STAGE DST CRYSTALLIZATION 3 DSTRUN6A.BIN RECYCLE 1,263 gm TOTAL gm TOTAL 20 gm SOLIDS gm SOLIDS 42 Temp Temp mole Na mole Na STEAM1 0.0 mole SO4 mole SO4 766 gm 0.1 mole CO3 mole CO3 40 C 3.1 moleno2 moleno2 4.0 mole NO3 mole NO3 2.4 mole Al mole Al E-04 mole Cs mole Cs DST FEED CRYSTALLIZER SLURRY 5 HYDROCYCLONE OVERFLOW 6 HYDROCLONE PURGE MIX 1,000 gm TOTAL 1,549 gm TOTAL 310 gm TOTAL 0 gm SOLIDS CO gm SOLIDS UNDERFLOW 7 - gm SOLIDS RECYC LIQ 8 BYPASS Temp gm TOTAL 40 Temp 1,239 gm TOTAL 40 Temp 356 gm TOTAL 8.46 gm TOTAL 5.5 mole Na 14.9 mole Na 619 gm SOLIDS 2.6 mole Na - gm SOLIDS 0.00 gm SOLIDS 0.0 mole SO4 0.0 mole SO4 40 Temp 0.0 mole SO4 40 Temp Temp 0.1 mole CO3 1.4 mole CO mole Na 0.0 mole CO3 2.9 mole Na mole Na 1.3 moleno2 4.4 moleno2 0.0 mole SO4 0.7 moleno2 0.0 mole SO mole SO4 1.2 mole NO3 5.2 mole NO3 1.3 mole CO3 0.6 mole NO3 0.0 mole CO mole CO3 0.6 mole Al 3.0 mole Al 3.7 moleno2 1.0 mole Al 0.8 moleno moleno2 6.79E-05 mole Cs 3.22E-04 mole Cs 4.6 mole NO3 1.07E-04 mole Cs 0.7 mole NO mole NO3 LIQUID DENSITY 1, gm/l 2.0 mole Al 1.1 mole Al mole Al VISCOSITY 7.66 cp 2.15E-04 mole Cs 1.23E-04 mole Cs 5.75E-07 mole Cs IONIC STRENGTH M Na DELIQUORING mole Cs LIQUOR CENTRIFUGE PURGE SPLIT PURGE 16 PURGE MIX MIXED PURGE gm TOTAL gm TOTAL gm TOTAL DELIQUORED 9 - gm SOLIDS - gm SOLIDS 0.00 gm SOLIDS 688 gm TOTAL 40 Temp 40 Temp 38.3 Temp 619 gm SOLIDS 4.6 mole Na mole Na mole Na RECYCLE RATIO Temp 0.0 mole SO mole SO mole SO4 SODIUM INCREASE 3.0% 7.7 mole Na 0.1 mole CO mole CO mole CO3 THEORETICAL YIELDS 0.0 mole SO4 1.2 moleno moleno moleno2 Na 71.5% 1.3 mole CO3 1.1 mole NO mole NO mole NO3 SO4 62.7% 2.5 moleno2 1.8 mole Al mole Al 0.63 mole Al CO3 97.7% 3.5 mole NO3 1.91E-04 mole Cs 6.75E-05 mole Cs 6.81E-05 mole Cs NO2 66.0% 0.2 mole Al NO3 67.4% 2.39E-05 mole Cs Al 0.6% WASH1 10 WASH 1 SPENT WASH1 11 Cs 0.6% 69 gm TOTAL 162 gm TOTAL - gm SOLIDS WASHED gm SOLIDS Cs in Product Ci/L 40 Temp 595 gm TOTAL 40 Temp D F mole Na 536 gm SOLIDS 1.2 mole Na [Na] in Product mole SO4 40 Temp 0.0 mole SO4 Na Split 71.5% - mole CO3 6.8 mole Na 0.0 mole CO3 - moleno2 0.0 mole SO4 0.4 moleno2 SO4/Na to WTP mole NO3 1.2 mole CO3 0.5 mole NO3 [NO3] mole Al 2.1 moleno mole Al [OH] E+00 mole Cs 2.9 mole NO3 1.75E-05 mole Cs [NO2] mole Al [OH]+[NO2] E-06 mole Cs [Na] WASH2 13 WASH 2 SPENT WASH gm TOTAL 435 gm TOTAL - gm SOLIDS WASHED gm SOLIDS 40 Temp 292 gm TOTAL 40 Temp - mole Na 263 gm SOLIDS 2.7 mole Na - mole SO4 40 Temp 0.0 mole SO4 - mole CO3 4.0 mole Na 0.0 mole CO3 - moleno2 0.0 mole SO4 1.2 moleno2 - mole NO3 1.2 mole CO3 2.1 mole NO3 - mole Al 0.8 moleno mole Al 0.00E+00 mole Cs 0.8 mole NO3 6.01E-06 mole Cs mole Al 4.04E-07 mole Cs DIL_H2O gm TOTAL 5M PRODUCT - gm SOLIDS 5M_PROD Temp 989 gm TOTAL - mole Na 0 gm SOLIDS - mole SO4 42 Temp - mole CO3 4.0 mole Na - moleno2 0.0 mole SO4 - mole NO3 1.2 mole CO3 - mole Al 0.8 moleno2 0.00E+00 mole Cs 0.8 mole NO3 0.0 mole Al 4.04E-07 mole Cs Ci/L

13 CONCLUSIONS HANFORD WASTE CHEMISTRY IS HIGHLY COMPLEX ESP CAN BE USED: TO RECONCILE WASTE ANALYSIS PERFORM REDOX AND EVAPORATION SURVEYS FLOWSHEET PROPOSED FRACTIONAL CRYSTALLIZATION PROCESS