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Influence of Anionic Polyacrylamides on Molybdenite Flotation
in Waters of Varying Ionic Strength
Ginna Jiménez
Department of Metallurgical Engineering, University of Concepcion, Chile
Leopoldo Gutiérrez
Department of Metallurgical Engineering, University of Concepcion, Chile
Water Research Center for Agriculture and Mining (CRHIAM), University of Concepcion, Chile
ABSTRACT: The use of seawater, as well as water recycling and recirculation, promise to be more efficient and
environmentally sustainable alternatives, especially in the mining industry, where they are increasingly adopted,
in particular in flotation processes. This has pushed research on the impact of the various substances present in
these processes on mineral recovery. In this study, an analysis of the flotability of molybdenite in the presence
of anionic polyacrylamides of low anionicity in solutions with varying ionic strength of CaCl2, CaSO4, MgCl2
and MgSO4, at different pH levels, has been carried out. The results obtained reveal that the interaction of
polyacrylamide with Ca and Mg ions significantly affects the flotability of molybdenite, especially at pH 9 and
11, where the mineral recovery is notably lower compared to pH 7.
INTRODUCTION
Water quality play a critical role in flotation processes.
This is pushing the mining industry to develop more effi-
cient and sustainable approaches that can reduce water
and energy consumption and improve water system design
and practice system (Gunson et al., 2012 Liu et al., 2013
Michaux et al., 2018 Michaux et al., 2020). Alternative
approaches such as water reuse, recycling and recirculation
are increasingly being explored in various industries, as well
as the use of seawater in mineral processing, especially in
the context of flotation (Michaux et al., 2019). The appli-
cation of recycling processes enables the complete reuse of
previously used water however, their implementation pres-
ents significant challenges, such as the transport of contam-
inants, including reagents, oils, detergents, and suspended
solids, as well as flocculants. These elements constitute sub-
stantial barriers to the direct reuse of recycled water, thus
requiring the overcoming of major obstacles in this process
(Liu et al., 2013 Michaux et al., 2019 Santos et al., 2021).
Most flocculants used in mineral processing are high
molecular weight polymers based on polyacrylamide (PAM),
which can be cationic, ionic or nonionic (Arinaitwe and
Pawlik 2013). Due to their composition, these polymers
require lower dosages and facilitate fine particle agglomera-
tion, which warrants their application in various industries
(Arinaitwe and Pawlik 2009 Hu et al., 2021 Kulicke et al.,
1982).In copper and molybdenum ore processing, PAM is
entrained with the recirculated water from the thickeners to
the milling and flotation circuits, which impacts the surface
properties of flotation suspensions (I. Castillo et al., 2020
Influence of Anionic Polyacrylamides on Molybdenite Flotation
in Waters of Varying Ionic Strength
Ginna Jiménez
Department of Metallurgical Engineering, University of Concepcion, Chile
Leopoldo Gutiérrez
Department of Metallurgical Engineering, University of Concepcion, Chile
Water Research Center for Agriculture and Mining (CRHIAM), University of Concepcion, Chile
ABSTRACT: The use of seawater, as well as water recycling and recirculation, promise to be more efficient and
environmentally sustainable alternatives, especially in the mining industry, where they are increasingly adopted,
in particular in flotation processes. This has pushed research on the impact of the various substances present in
these processes on mineral recovery. In this study, an analysis of the flotability of molybdenite in the presence
of anionic polyacrylamides of low anionicity in solutions with varying ionic strength of CaCl2, CaSO4, MgCl2
and MgSO4, at different pH levels, has been carried out. The results obtained reveal that the interaction of
polyacrylamide with Ca and Mg ions significantly affects the flotability of molybdenite, especially at pH 9 and
11, where the mineral recovery is notably lower compared to pH 7.
INTRODUCTION
Water quality play a critical role in flotation processes.
This is pushing the mining industry to develop more effi-
cient and sustainable approaches that can reduce water
and energy consumption and improve water system design
and practice system (Gunson et al., 2012 Liu et al., 2013
Michaux et al., 2018 Michaux et al., 2020). Alternative
approaches such as water reuse, recycling and recirculation
are increasingly being explored in various industries, as well
as the use of seawater in mineral processing, especially in
the context of flotation (Michaux et al., 2019). The appli-
cation of recycling processes enables the complete reuse of
previously used water however, their implementation pres-
ents significant challenges, such as the transport of contam-
inants, including reagents, oils, detergents, and suspended
solids, as well as flocculants. These elements constitute sub-
stantial barriers to the direct reuse of recycled water, thus
requiring the overcoming of major obstacles in this process
(Liu et al., 2013 Michaux et al., 2019 Santos et al., 2021).
Most flocculants used in mineral processing are high
molecular weight polymers based on polyacrylamide (PAM),
which can be cationic, ionic or nonionic (Arinaitwe and
Pawlik 2013). Due to their composition, these polymers
require lower dosages and facilitate fine particle agglomera-
tion, which warrants their application in various industries
(Arinaitwe and Pawlik 2009 Hu et al., 2021 Kulicke et al.,
1982).In copper and molybdenum ore processing, PAM is
entrained with the recirculated water from the thickeners to
the milling and flotation circuits, which impacts the surface
properties of flotation suspensions (I. Castillo et al., 2020