Applied thermodynamics in nuclear industry modelling of precipitation processes

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HAL Id: cea-02338737

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Applied thermodynamics in nuclear industry modelling

of precipitation processes

M. Bertrand, S. Lalleman, L.-Z. Mojica-Rodriguez, C. Sorel, P. Moisy, F.

Auger, E. Plasari, H. Muhr

To cite this version:

M. Bertrand, S. Lalleman, L.-Z. Mojica-Rodriguez, C. Sorel, P. Moisy, et al.. Applied thermody-namics in nuclear industry modelling of precipitation processes: Taking account for ideality deviation in neodymium oxalate and uranium peroxide precipitation. ESAT 2018, Jun 2018, Prague, Czech Republic. �cea-02338737�

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Applied thermodynamics in nuclear

industry: modelling of precipitation

processes

Taking account for ideality deviation in

neodymium oxalate and uranium peroxide

precipitation

| PAGE 1

ESAT 2018, June 2018, Prague

Murielle Bertrand (CEA Marcoule)

Sophie Lalleman, Luz-Adriana Mojica-Rodriguez,

Christian Sorel, Philippe Moisy (CEA Marcoule)

Frédéric Auger (Areva Mines)

(3)

PRECIPITATION PROCESS MODELLING

Precipitation Modelling :

Coupling Chemistry/Turbulence

 

) ( , ) , ( ) , ( ) , ( 1 L N R V t L Q t L Q L t L G t t L V V i i o  _          

Population balance

CFD simulation

Kinetics

Thermodynamics

10µm

1µm

(4)

Calculation of Supersaturation

3

 Objective:

Calculation of the driving force = supersaturation S during the precipitation process

In concentrated solutions involving salts and ions of high valence

 Coefficient activity models:

Physico-chemical approaches

Pitzer equations

Empirical approaches

Bromley method or

SIT specific interaction theory

          

















ν ν 1 ν eq , X ν eq , M ν X ν M z z z z

a

S

O

.xH

X

M

X

ν

M

ν

ν ν 2 O H -z z 2     









Good compromise

J

:

Easy-to-use / accuracy for process modelling

and CFD simulations

Inconvenient

L



Heavy implementation + many parameters to

be adjusted

(5)

 2 examples of applications in nuclear industry:

Actinide / lanthanide oxalate precipitation

very low solubility

 widely used in the Ln and An separation, analytical chemistry and

treatment of high-level liquid wastes - in nitric acid medium

Uranium peroxide precipitation

Applications

From uranium ore U < 1%

to yellow cake U ~ 75 % Uranium ore processing

Crushing grinding

Leaching U extraction Precipitation

(6)

2 -Neodymium oxalate

precipitation

The Bromley method

1. Context of the study

2. Neodymium oxalate

Bromley method

Determination of the individual

contributions

3. Uranium peroxide

Specific interaction theory

Determination of the specific

interaction coefficients

4. Conclusions

10µm

(7)

 Bromley method for multicomponent systems

Based on the contributions B

_M1X1

of every electrolytes present in solution

 Neodymium individual contributions

Tabulated by Bromley in 1973

After  New experimental binary data published

later for neodymium nitrate and chloride

 The Bromley model not in good agreement

 Determination of new values for neodymium

contributions (B

₊

,δ

₊

) using tow salts:

Neodymium nitrate + Neodymium chloride

Bromley model

   







B

1 1X M 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 1 2 3 4 5 6

Ionic strength [mol kg-1]

A c ti v it y c o e ff ic ie n t [-]

Exp. data (Rard and Miller, 1979)

Davies and Jones' model (Söhnel and Garside, 1992) Bromley's model (Bromley, 1973)

   





3 3 3 3 3 3) Nd NO Nd NO Nd(NO

B

δ

B

   





Cl Nd Cl Nd NdCl

B

δ

B

3 3 3

(8)

Very good agreement between exp. data and the Bromley model combined with

the contributions of HNO

₃

and HCl

New contributions of Nd

3+

_{in the Bromley model}

7

[1] Rard J.A. and Miller D.G, 1979. J. Chem. Eng. Data 24, 348-353 [2] Spedding et al., 1976. J. chem. Eng. Data 21, 341-360.

1

st

_{STEP: Validation of the Bromley individual contributions for NO}

3-

and Cl

-from experimental data of HNO

₃

and HCl

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 1 2 3 4 5 6

Experimental data (Charrin, 1999)

Bromley model with B = 0.0776 (Bromley, 1973)

HNO

₃

0 0.5 1 1.5 2 2.5 3 3.5 4 0 1 2 3 4 5 6

Experimental data (Hamer and Wu, 1972) Bromley model with B = 0.1433 (Bromley, 1973)

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New contributions of Nd

3+

_{in the Bromley model}

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 1 2 3 4 5 6

Exp. data (Rard and Miller, 1979)

Bromley's model with the new B value (Bromley, 1973)

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 1 2 3 4 5 6

Exp. data (Spedding et al., 1976)

Bromley's model with the new B value (Bromley, 1973)

Very good agreement between exp. data and the Bromley model with the new

contributions of Nd(NO

₃

)

₃

et NdCl

₃

Nd(NO

₃

)

₃

=>

NdCl

₃

=>

2

nd

_{STEP: Determination of the salt contributions and adjustment of the}

Bromley contributions for Nd

3+

0511

.

0 B

3 3) Nd(NO



B

NdCl₃



0 .

0855

163 .

0 and

0.0321

B











B





0.0321

0.035

and







0 .

0.27

163

(10)

Application of the Bromley model to ternary

mixtures

9

 These new contributions  application to ternary solutions

Nd(NO

₃

)

₃

/HNO

₃

/H

₂

O

 Measurements of water activity a

_W

in ternary mixtures

Using the concept of simple solutions and Mikulin equation*:

a

_W

 activity coefficients 𝛾

_{𝑁𝑑(𝑁𝑂3)}𝑚𝑖𝑥𝑡𝑢𝑟𝑒

 Comparison with the values given by the Bromley method

Variable-impedance hygrometer

AW Center

TM

_(Novasina)

0 0,05 0,1 0,15 0,2 0,25 0,3 2 3 4 5 6 7 8 9 n eo d ym iu m act iv ity co ef fici en t [-]

Ionic strength [mol.kg-1)

Comparison experiments / Bromley model

Bromley model Experimental

J

I < 6 mol.kg

-1

Deviation within 9%

L

I > 6 mol.kg

-1

 Deviation 

* Charrin et al., 1999. Radiochim. Acta 86, 143-149.

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3 -Uranium Peroxide

precipitation

SIT

1. Context of the study

2. Neodymium oxalate

Bromley method

Determination of the individual

contributions

3. Uranium peroxide

Specific interaction theory

Determination of the specific

interaction coefficients

4. Conclusions

1µm

(12)

 Precipitation in sulphuric media

UO

₂

SO

₄

/ H

₂

SO

₄

/ Na

₂

SO

₄

/ H

₂

O

₂

/ H

₂

O

Bromley method not adapted: sulphuric acid partially dissociated

+ no data for hydrogen peroxide

 Specific Interaction Theory* **

Based on specific interaction coefficients between ions of opposite charge

 1

st

_{step: Validation of the specific interaction coefficients of ions: SO}

42-

, HSO

4-

and H

+

Comparison between experimental pH

and pH calculated using SIT

in ternary systems H

₂

SO

₄

- Na

₂

SO

₄

- H

₂

O

Specific Interaction Theory SIT

11 eq O eq UO O UO

a

S

, , ₂2 2 2 2 2 2 2    



𝑈𝑂

22+

+ 𝑂

22−

+ 4𝐻

2

𝑂 ↔ 𝑈𝑂

2

(𝑂

2

) ∙ 4𝐻

2

𝑂

*T. Vercouter, B. Amekraz, C. Moulin, E. Giffaut and P. Vitorge, Inorg. Chem., 2005, 44, 7570–7581Bromley L.A., 1973. AIChE J. 19, 313-320 **R. M. Cigala, F. Crea, C. De Stefano, G. Lando, D. Milea and S. Sammartano, Geochim. Cosmochim. Acta, 2012, 87, 1–20

Specific interaction coefficient









j j j i, 2 i i

ε(i,

j)m

I

b

1 I

a

z

logγ

Very good agreement between

experimental pH and SIT

(13)

Determination of specific interaction coefficients

 2

nd

_{step: determination of the specific interaction coefficients of other ions}

from experimental data of uranium peroxide solubility (ICP-AES and ICP-MS)

And by application of the SIT hypothesis:

Commutative function

(i,j) = (j,i)

Independent from I

(i,j) = 0 for ions of same charge

For unknown coefficients  analogies between ions of same charge

ε (kg.mol

-1

₎

UO

₂2+

_Na

+

_H

+

SO

₄2-

_0,12

_-0,12

_{± 0,06}

_→

_-0,18

₀

_→

_0,046

HSO

₄-

_{0,46 ± 0,03 → 0,46}

_-0,01

_{± 0,02}

_→

_-0,03

_{-0,01 ± 0,02}

_{→ -0,01}

UO

₂

(SO

₄

)

₂2-

_0,12

_-0,12

_{± 0,06}

_→

_-0,18

_{-0,12 ± 0,06 → -0,12}

UO

₂

(SO

₄

)

₃4-

_0,24

_-0,06

_-0,24

- blue:

from the literature

- green

: by analogy

- red:

optimised values from

experimental data

(14)

Determination of specific interaction coefficients

13 1E-08 1E-07 1E-06 1E-05 1E-04 1E-03 1E-02 1E-01 1E-08 1E-07 1E-06 1E-05 1E-04 1E-03 1E-02 1E-01

[U] exp (mol/L)

[U ] c a lc ( m o l/ L )

 Comparison between experimental and calculated solubilities over a wide range of operating

conditions

Good agreement

higher deviations at low sulphate concentrations 

very low solubilities  high analytical uncertainties

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