1722
Kinetics of Cobalt and Manganese Precipitation from Acid Mine
Drainage Using Ozone
Younes Shekarian, Mohammad Rezaee, Sarma Pisupati
John and Willie Leone Family Department of Energy and Mineral Engineering,
Center for Critical Minerals, EMS Energy Institute, College of Earth and Mineral Sciences,
The Pennsylvania State University, University Park, Pennsylvania, USA
ABSTRACT: Cobalt (Co) and manganese (Mn) are among the critical elements listed by the U.S. Department
of Interior, and Acid Mine Drainage (AMD) is one of the potential secondary resources for these elements.
Recovery of these elements from AMD requires elevated pH (~9) or utilizing costly oxidants. Building upon our
previously published work (patent-pending), the ozone oxidative precipitation process was employed to minimize
chemical usage and efficiently recover these elements from AMD. The effects of process parameters (specifically,
gas-flow rate, stirring rate, and temperature) on precipitation of Co-Mn from AMD were investigated. It was
found that Co-Mn recovery is enhanced by increasing gas flow rate, temperature, and stirring rate to certain
values, below which the results were not significantly different at 95% confidence level. Furthermore, a kinetic
study of the Co-Mn oxidative precipitation was performed, and the activation energy values of the reactions
were calculated. The effect of process parameters, along with the calculated activation energy values using the
Pseudo-homogeneous model, collectively suggested that the ozone oxidative precipitation of Co-Mn is likely
diffusion-controlled.
Keywords: acid mine drainage, cobalt, manganese, precipitation, ozone, kinetic study
INTRODUCTION
The identification of Cobalt (Co) and manganese (Mn) as
critical elements by the U.S. Department of the Interior
emphasizes a growing concern for the nation’s reliance on
foreign sources of these elements. (USGS 2022 a&b, IEA
2023). This dependency is particularly significant given
the increasing demand for Co and Mn driven by their
pivotal role as battery materials in electric vehicles (IEA
2023 Rozelle et al., 2021). Recognizing the limited pri-
mary resources of Co and Mn within the United States,
it becomes imperative to extract these elements from vari-
ous viable secondary sources. Acid mine drainage (AMD),
the waste stream associated with coal and sulfide minerals,
has long been of environmental concern but was recently
found to be a viable source of multi-critical elements such
as aluminum, rare earth elements (REEs), Co, and Mn.
(Johnson and Hallberg, 2005 Skousen et al., 2019 Vaziri
Hassas et al., 2022). As per the Clean Water Act guide-
lines (Act33 U.S.C. §1251), these streams are required to
be neutralized and treated prior to discharge to the envi-
ronment. The cost associated with such treatment could
be substantial, depending on the AMD’s acidity level and
flow rate. Recovery of critical elements from AMD while
treating for environmental compliance not only offsets
the treatment cost but also enhances the sustainability of
the process by converting these waste streams to valuable
Kinetics of Cobalt and Manganese Precipitation from Acid Mine
Drainage Using Ozone
Younes Shekarian, Mohammad Rezaee, Sarma Pisupati
John and Willie Leone Family Department of Energy and Mineral Engineering,
Center for Critical Minerals, EMS Energy Institute, College of Earth and Mineral Sciences,
The Pennsylvania State University, University Park, Pennsylvania, USA
ABSTRACT: Cobalt (Co) and manganese (Mn) are among the critical elements listed by the U.S. Department
of Interior, and Acid Mine Drainage (AMD) is one of the potential secondary resources for these elements.
Recovery of these elements from AMD requires elevated pH (~9) or utilizing costly oxidants. Building upon our
previously published work (patent-pending), the ozone oxidative precipitation process was employed to minimize
chemical usage and efficiently recover these elements from AMD. The effects of process parameters (specifically,
gas-flow rate, stirring rate, and temperature) on precipitation of Co-Mn from AMD were investigated. It was
found that Co-Mn recovery is enhanced by increasing gas flow rate, temperature, and stirring rate to certain
values, below which the results were not significantly different at 95% confidence level. Furthermore, a kinetic
study of the Co-Mn oxidative precipitation was performed, and the activation energy values of the reactions
were calculated. The effect of process parameters, along with the calculated activation energy values using the
Pseudo-homogeneous model, collectively suggested that the ozone oxidative precipitation of Co-Mn is likely
diffusion-controlled.
Keywords: acid mine drainage, cobalt, manganese, precipitation, ozone, kinetic study
INTRODUCTION
The identification of Cobalt (Co) and manganese (Mn) as
critical elements by the U.S. Department of the Interior
emphasizes a growing concern for the nation’s reliance on
foreign sources of these elements. (USGS 2022 a&b, IEA
2023). This dependency is particularly significant given
the increasing demand for Co and Mn driven by their
pivotal role as battery materials in electric vehicles (IEA
2023 Rozelle et al., 2021). Recognizing the limited pri-
mary resources of Co and Mn within the United States,
it becomes imperative to extract these elements from vari-
ous viable secondary sources. Acid mine drainage (AMD),
the waste stream associated with coal and sulfide minerals,
has long been of environmental concern but was recently
found to be a viable source of multi-critical elements such
as aluminum, rare earth elements (REEs), Co, and Mn.
(Johnson and Hallberg, 2005 Skousen et al., 2019 Vaziri
Hassas et al., 2022). As per the Clean Water Act guide-
lines (Act33 U.S.C. §1251), these streams are required to
be neutralized and treated prior to discharge to the envi-
ronment. The cost associated with such treatment could
be substantial, depending on the AMD’s acidity level and
flow rate. Recovery of critical elements from AMD while
treating for environmental compliance not only offsets
the treatment cost but also enhances the sustainability of
the process by converting these waste streams to valuable