2325
Unravelling the Interaction Between Amine Collectors
and Kaolinite Through Adsorption Isotherms and
Molecular Modelling
J. Lainé
ArcelorMittal Global R&D, Maizières-lès-Metz, France
Université de Lorraine, France
J.-W. Hounfodji, Y. Foucaud, M. Badawi
Université de Lorraine, France
H. Turrer
ArcelorMittal Global R&D, Maizières-lès-Metz, France
ABSTRACT: In the context of iron oresw reverse flotation, the adsorption behaviours of dodecylamine (DDA)
and 3-dodecyloxypropylamine (EA), two frequent collectors, were investigated through adsorption isotherms
at three temperatures onto kaolinite, a common gangue mineral from iron ores. DDA and EA molecules form
a monolayer of molecules with adsorbed quantities of 4.5 and 6 µmol.m–2, respectively, and packing area
were estimated at around 38 Å2 for DDA and around 25 Å2 for EA. Static DFT calculations showed that the
difference of behaviour was due to chain-chain interactions and the presence of the oxygen within the chain.
Keywords: flotation, iron ore, DFT, adsorption, dodecylamine, etheramine
INTRODUCTION
Iron is the main component of steel which is a staple
material for human activities (transportation, construc-
tion, products, …). Although recycling is showing great
performance, virgin ores remain an important source of
iron worldwide. If magnetic and gravity separations are the
more followed beneficiation routes, the new fineness and
mineralogic complexity of iron ores obliges the mines to
require to other process route like froth flotation.
Among the common gangue minerals from iron ores,
kaolinite is an important source of aluminium impurities in
iron ores concentrates and the cause for bad performances
of metallurgical processes. However, it is known that
kaolinite is known to float well in acidic medium using
cationic collectors (Barani and Kalantari, 2018 Yuehua et
al., 2004) and iron ores flotation routes usually implies a
reverse flotation using amine-based collectors (Araujo et al.,
2005 Papini et al., 2001). Thus, the present work addresses
the question of two specific amines adsorption, dodecyl-
ammonium chloride (DDA), and 3-dodecyloxypropylam-
monium chloride (EA), on kaolinite surfaces. DDA is a
common aliphatic amine found in industrial reagent and
EA is one pure example of etheramines close to the struc-
ture of DDA. It will allow to acknowledge the influence
Unravelling the Interaction Between Amine Collectors
and Kaolinite Through Adsorption Isotherms and
Molecular Modelling
J. Lainé
ArcelorMittal Global R&D, Maizières-lès-Metz, France
Université de Lorraine, France
J.-W. Hounfodji, Y. Foucaud, M. Badawi
Université de Lorraine, France
H. Turrer
ArcelorMittal Global R&D, Maizières-lès-Metz, France
ABSTRACT: In the context of iron oresw reverse flotation, the adsorption behaviours of dodecylamine (DDA)
and 3-dodecyloxypropylamine (EA), two frequent collectors, were investigated through adsorption isotherms
at three temperatures onto kaolinite, a common gangue mineral from iron ores. DDA and EA molecules form
a monolayer of molecules with adsorbed quantities of 4.5 and 6 µmol.m–2, respectively, and packing area
were estimated at around 38 Å2 for DDA and around 25 Å2 for EA. Static DFT calculations showed that the
difference of behaviour was due to chain-chain interactions and the presence of the oxygen within the chain.
Keywords: flotation, iron ore, DFT, adsorption, dodecylamine, etheramine
INTRODUCTION
Iron is the main component of steel which is a staple
material for human activities (transportation, construc-
tion, products, …). Although recycling is showing great
performance, virgin ores remain an important source of
iron worldwide. If magnetic and gravity separations are the
more followed beneficiation routes, the new fineness and
mineralogic complexity of iron ores obliges the mines to
require to other process route like froth flotation.
Among the common gangue minerals from iron ores,
kaolinite is an important source of aluminium impurities in
iron ores concentrates and the cause for bad performances
of metallurgical processes. However, it is known that
kaolinite is known to float well in acidic medium using
cationic collectors (Barani and Kalantari, 2018 Yuehua et
al., 2004) and iron ores flotation routes usually implies a
reverse flotation using amine-based collectors (Araujo et al.,
2005 Papini et al., 2001). Thus, the present work addresses
the question of two specific amines adsorption, dodecyl-
ammonium chloride (DDA), and 3-dodecyloxypropylam-
monium chloride (EA), on kaolinite surfaces. DDA is a
common aliphatic amine found in industrial reagent and
EA is one pure example of etheramines close to the struc-
ture of DDA. It will allow to acknowledge the influence