XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1305
reports a 0% rate for strontium in the EU (European
Commission, 2023).
However, there is an untapped potential in the recy-
cling of strontium from waste CRTs. Since the late 1990s,
efforts focused on the development of recycling technolo-
gies for producing secondary raw materials from CRT glass
(Andreola et al., 2007 Herat, 2008), associated with the
Waste Electrical and Electronic Equipment (WEEE) direc-
tive. The main challenges for CRT glass recycling are the
high contents of lead and cadmium in the glass, as well
as the reluctance from glass fibre manufacturers to accept
high contents of strontium in their process (Herat, 2008).
Consequently, most efforts focused on the extraction and
“detoxification” of the glass, involving techniques such as
strontium leaching from foam glass (Yot &Méar, 2011).
Similarly, Xing et al. (2018) proposed a process for the
extraction of barium and strontium from waste CRT glass
based on pyrometallurgy and phase separation, achieving
the removal of 99.4% of the strontium.
In recent years, research efforts have focused on the
recycling of CRT glass through the production of ceram-
ics. For example, Karaahmet &Cicek (2019) proposed a
methodology for recycling CRT glass with high barium and
strontium content to produce transparent ceramic frits, as
the presence of strontium resulted in glossy surfaces with
a more decorative appearance, often called a “soft glaze”.
Other strontium-recycling efforts have focused on the
recycling of strontium ferrite waste from permanent mag-
net production (Bollero et al., 2017) and the recycling of
high-purity strontianite from sludge using acid leaching
(Bian et al., 2020). Yet, industrial recycling efforts are still
lacking and are far from replacing the demand for primary
extraction.
While emphasizing circularity is relevant for the future,
it is equally crucial to assess the environmental impact of
strontium production from both primary and secondary
sources. Although the EU is one of the major produc-
ers of strontium globally, with a share of 34%, there is a
notable absence of studies investigating the environmen-
tal impacts of its production process. Addressing this gap,
the European project ROTATE (ROTATE, 2022), focused
on providing environmental solutions for the mining and
quarrying industry, has selected the Spanish celestine mine
of Canteras Industriales (see Figure 6) as a case study. For
this specific site, the project aims to assess and quantify the
environmental impacts of the produced celestine concen-
trate in different size fractions and develop a recovery pro-
cess to treat celestine tailings to recover valuable mineral
particles.
Novel and Future Applications for Strontium
In recent decades, the application landscape for strontium
has evolved significantly due to technological changes.
Following the decline in CRT glass production, a major
use of strontium has been in the production of ceramic
magnets, as shown in Figure 5. Almost 80% of the per-
manent magnets contain rare-earth elements (REE), which
are expensive and primarily dominated by Chinese produc-
tion (Grand View Research, 2023 Guzmán-Mínguez et
al., 2020). Thus, the emergence of strontium-based mag-
nets as an alternative to REE has caught the attention of
researchers and may play a fundamental role in the future
of strontium. Examples include the development of FeCo
nanowire-strontium ferrite powder composites (Guzmán-
Mínguez et al., 2020), the first dense strontium hexafer-
rite-based rare-earth-free composite permanent magnets
assisted by cold sintering process (García-Martín et al.,
2022), and anisotropic strontium hexaferrite nanomagnets
(Lee et al., 2020).
Beyond magnets, strontium-based nanoparticles find
applications in medicine and environmental sciences, par-
ticularly in bone and tissue engineering due to their similar-
ities with essential trace metals like calcium and magnesium
(Mukherjee &Mishra, 2021). Additionally, strontium-alu-
minate-based materials are being explored for smart mech-
anoluminescent phosphors, offering applications in stress
visualisation, crack detection, advanced lighting, imaging,
and luminous fabrics (Huang et al., 2023). Smart windows
made of recycled polycarbonate plastic immobilised with
strontium aluminate phosphor nanoparticles are proposed
for maximising light transmission with minimal energy
consumption (El-Hefnawy et al., 2023), while other stud-
ies have explored strontium-aluminate for afterglow and
photochromic translucent wood in smart window applica-
tions (Binyaseen et al., 2024).
REFERENCES
Andreola, F., Barbieri, L., Corradi, A., &Lancellotti, I.
(2007). CRT glass state of the art: A case study:
Recycling in ceramic glazes. Journal of the European
Ceramic Society, 27(2), 1623–1629. doi: 10.1016
/j.jeurceramsoc.2006.05.009.
Ariza-Rodríguez, N., Rodríguez-Navarro, A.B., Calero
de Hoces, M., Martin, J.M., &Muñoz-Batista, M.J.
(2022). Chemical and Mineralogical Characterization
of Montevive Celestine Mineral. Minerals, 12(10),
Article 10. doi: 10.3390/min12101261.
reports a 0% rate for strontium in the EU (European
Commission, 2023).
However, there is an untapped potential in the recy-
cling of strontium from waste CRTs. Since the late 1990s,
efforts focused on the development of recycling technolo-
gies for producing secondary raw materials from CRT glass
(Andreola et al., 2007 Herat, 2008), associated with the
Waste Electrical and Electronic Equipment (WEEE) direc-
tive. The main challenges for CRT glass recycling are the
high contents of lead and cadmium in the glass, as well
as the reluctance from glass fibre manufacturers to accept
high contents of strontium in their process (Herat, 2008).
Consequently, most efforts focused on the extraction and
“detoxification” of the glass, involving techniques such as
strontium leaching from foam glass (Yot &Méar, 2011).
Similarly, Xing et al. (2018) proposed a process for the
extraction of barium and strontium from waste CRT glass
based on pyrometallurgy and phase separation, achieving
the removal of 99.4% of the strontium.
In recent years, research efforts have focused on the
recycling of CRT glass through the production of ceram-
ics. For example, Karaahmet &Cicek (2019) proposed a
methodology for recycling CRT glass with high barium and
strontium content to produce transparent ceramic frits, as
the presence of strontium resulted in glossy surfaces with
a more decorative appearance, often called a “soft glaze”.
Other strontium-recycling efforts have focused on the
recycling of strontium ferrite waste from permanent mag-
net production (Bollero et al., 2017) and the recycling of
high-purity strontianite from sludge using acid leaching
(Bian et al., 2020). Yet, industrial recycling efforts are still
lacking and are far from replacing the demand for primary
extraction.
While emphasizing circularity is relevant for the future,
it is equally crucial to assess the environmental impact of
strontium production from both primary and secondary
sources. Although the EU is one of the major produc-
ers of strontium globally, with a share of 34%, there is a
notable absence of studies investigating the environmen-
tal impacts of its production process. Addressing this gap,
the European project ROTATE (ROTATE, 2022), focused
on providing environmental solutions for the mining and
quarrying industry, has selected the Spanish celestine mine
of Canteras Industriales (see Figure 6) as a case study. For
this specific site, the project aims to assess and quantify the
environmental impacts of the produced celestine concen-
trate in different size fractions and develop a recovery pro-
cess to treat celestine tailings to recover valuable mineral
particles.
Novel and Future Applications for Strontium
In recent decades, the application landscape for strontium
has evolved significantly due to technological changes.
Following the decline in CRT glass production, a major
use of strontium has been in the production of ceramic
magnets, as shown in Figure 5. Almost 80% of the per-
manent magnets contain rare-earth elements (REE), which
are expensive and primarily dominated by Chinese produc-
tion (Grand View Research, 2023 Guzmán-Mínguez et
al., 2020). Thus, the emergence of strontium-based mag-
nets as an alternative to REE has caught the attention of
researchers and may play a fundamental role in the future
of strontium. Examples include the development of FeCo
nanowire-strontium ferrite powder composites (Guzmán-
Mínguez et al., 2020), the first dense strontium hexafer-
rite-based rare-earth-free composite permanent magnets
assisted by cold sintering process (García-Martín et al.,
2022), and anisotropic strontium hexaferrite nanomagnets
(Lee et al., 2020).
Beyond magnets, strontium-based nanoparticles find
applications in medicine and environmental sciences, par-
ticularly in bone and tissue engineering due to their similar-
ities with essential trace metals like calcium and magnesium
(Mukherjee &Mishra, 2021). Additionally, strontium-alu-
minate-based materials are being explored for smart mech-
anoluminescent phosphors, offering applications in stress
visualisation, crack detection, advanced lighting, imaging,
and luminous fabrics (Huang et al., 2023). Smart windows
made of recycled polycarbonate plastic immobilised with
strontium aluminate phosphor nanoparticles are proposed
for maximising light transmission with minimal energy
consumption (El-Hefnawy et al., 2023), while other stud-
ies have explored strontium-aluminate for afterglow and
photochromic translucent wood in smart window applica-
tions (Binyaseen et al., 2024).
REFERENCES
Andreola, F., Barbieri, L., Corradi, A., &Lancellotti, I.
(2007). CRT glass state of the art: A case study:
Recycling in ceramic glazes. Journal of the European
Ceramic Society, 27(2), 1623–1629. doi: 10.1016
/j.jeurceramsoc.2006.05.009.
Ariza-Rodríguez, N., Rodríguez-Navarro, A.B., Calero
de Hoces, M., Martin, J.M., &Muñoz-Batista, M.J.
(2022). Chemical and Mineralogical Characterization
of Montevive Celestine Mineral. Minerals, 12(10),
Article 10. doi: 10.3390/min12101261.