1164
Use of Nanofiltration Membrane Processes to Concentrate Acid
Liquors in Extractive Metallurgy: Development of a Reactive
Transport Model
Thomas Porqueddu, Baptiste Laubie, Marie-Odile Simmonot
Université de Lorraine, CNRS, LRGP
Anthony Szymczyk
Univ Rennes, CNRS, ISCR–UMR 6226, Rennes, France
ABSTRACT: The advent of membranes, such as the Suez Duracid nanofiltration membrane, makes it possible
to consider membrane recycling processes for highly acidic leachates (with a sulfuric acid mass concentration of
between 5 and 20%). As nanofiltration of this type of leachate is a relatively new practice, a reactive transport
model based on the SEDE model has been proposed. The leachate studied was a hyperaccumulator plant ash
leachate, chosen for the metals of interest present in solution, but also to highlight a secondary source of metal
supply. In order to study the impact of the separation of such a concentrated solution, several dilutions were
made to assess the impact of the ionic strength of the solution on the nanofiltration.
The simulation approach followed the classical strategy of mechanistic modelling: steric hindrance, image force,
Donnan effect and Born effect were added gradually, to assess their importance in separation. Finally, to deter-
mine the contribution of coupling a speciation model to the SEDE model, a reactive transport model has been
proposed, and the results compared to a simple SEDE simulation.
The comparison showed a marked improvement in the simulation of the rejection rates for three reference ions
when speciation was considered. This effect was more significant if a phenomenon related to ion charge, such
as the Donnan effect, had an impact on separation. Indeed, in this case, the simulation results were five times
more accurate when considering the speciation of the feed solution.
INTRODUCTION
In March 2023, the European Union took measures to
guarantee continued access to strategic metals. To ensure its
resilience, the EU has decided that by 2030 it will produce
15% of its critical materials needs through recycling. The
list of materials concerned (including 34 materials, such as
nickel or magnesium) is crucial to many emerging technol-
ogies, such as electric vehicles. All these elements have one
thing in common: the majority of them are produced out-
side the EU, and are necessary to ensure the energy transi-
tion (European Commission 2023). For example, nickel is
a metal used very regularly in metallurgy, especially for the
manufacture of stainless steel. Nickel alloys can be found
in the chemical industry, the food industry, transport,
buildings and domestic equipment. Indonesia produces
41% of all the nickel consumed worldwide, followed by
Use of Nanofiltration Membrane Processes to Concentrate Acid
Liquors in Extractive Metallurgy: Development of a Reactive
Transport Model
Thomas Porqueddu, Baptiste Laubie, Marie-Odile Simmonot
Université de Lorraine, CNRS, LRGP
Anthony Szymczyk
Univ Rennes, CNRS, ISCR–UMR 6226, Rennes, France
ABSTRACT: The advent of membranes, such as the Suez Duracid nanofiltration membrane, makes it possible
to consider membrane recycling processes for highly acidic leachates (with a sulfuric acid mass concentration of
between 5 and 20%). As nanofiltration of this type of leachate is a relatively new practice, a reactive transport
model based on the SEDE model has been proposed. The leachate studied was a hyperaccumulator plant ash
leachate, chosen for the metals of interest present in solution, but also to highlight a secondary source of metal
supply. In order to study the impact of the separation of such a concentrated solution, several dilutions were
made to assess the impact of the ionic strength of the solution on the nanofiltration.
The simulation approach followed the classical strategy of mechanistic modelling: steric hindrance, image force,
Donnan effect and Born effect were added gradually, to assess their importance in separation. Finally, to deter-
mine the contribution of coupling a speciation model to the SEDE model, a reactive transport model has been
proposed, and the results compared to a simple SEDE simulation.
The comparison showed a marked improvement in the simulation of the rejection rates for three reference ions
when speciation was considered. This effect was more significant if a phenomenon related to ion charge, such
as the Donnan effect, had an impact on separation. Indeed, in this case, the simulation results were five times
more accurate when considering the speciation of the feed solution.
INTRODUCTION
In March 2023, the European Union took measures to
guarantee continued access to strategic metals. To ensure its
resilience, the EU has decided that by 2030 it will produce
15% of its critical materials needs through recycling. The
list of materials concerned (including 34 materials, such as
nickel or magnesium) is crucial to many emerging technol-
ogies, such as electric vehicles. All these elements have one
thing in common: the majority of them are produced out-
side the EU, and are necessary to ensure the energy transi-
tion (European Commission 2023). For example, nickel is
a metal used very regularly in metallurgy, especially for the
manufacture of stainless steel. Nickel alloys can be found
in the chemical industry, the food industry, transport,
buildings and domestic equipment. Indonesia produces
41% of all the nickel consumed worldwide, followed by