526 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Further, 17% of the particles are below 0.106 mm
in the slag.
• XRD analysis of the slag samples concluded that
Calcium-bearing silicates are the major phases
(Brownmillerite, Hatrurite, Brownmillerite (Mg,
Si-exchanged), Dicalcium Silicate -Alpha. Iron is
reported in Wuestite and Dicalcium Diiron(III)
Oxide as a major phase.
• Phase analysis in SEM-EDS indicated that iron is
segregated as Fe-metal, wustite, and interlocked
with magnesium oxide as well as with calcium sili-
cate at secondary phases. Phosphorous is found to
be concentrated on calcium silicate phases, whereas
alumina does not have any correlation. Further lib-
eration is necessary for the effective separation of
iron and Ca-bearing phases in the slag. However,
the exact liberation size of individual phases, along
with their volume, can be quantified by using MLA/
QEMSCAN.
• Similarly, magnetization studies were carried out and
concluded that the saturation magnetization value at
3 T is 3.1.
• Magnetic separation of as-received samples in
RERMS indicated the marginal efficiency in the
separation of iron-bearing minerals because of higher
magnetic field intensity over the roll surface. A maxi-
mum iron enrichment of 20.68% Fe(T) from 17.5%
was reported at a roll speed of 350rpm and splitter
position 3.
• In REDMS, at a drum speed of 90 rpm, iron was
found to be enriched up to 24.65 Fe(T) with a recov-
ery of 44.77% for the as-received sample.
• In a dry low-intensity magnetic separator, iron was
found to be enriched up to 29.6% Fe(T) in the
coarser size fractions of –3 mm at a drum speed of
42 rpm. Thus, the above findings suggest that multi-
stage magnetic separation using a low-intensity mag-
netic separator (LIMS) can be employed to maximize
the enrichment of iron-bearing phases from the slag.
• Magnetic fraction products can be utilized by recy-
cling into the secondary steel-making process or
through the sintering process, where the balance
between CaO and iron can be manipulated. Other
separation techniques can also be studied for better
decision-making.
• Similarly, the non-magnetic fraction products can
be studied for aggregate or cement industries to take
advantage of zero-carbon Ca-rich material with a
lower amount of iron, which will help in reducing
the overall fusion temperature of the clinker in the
cement manufacturing process. However, a detailed
study in this direction will be a way forward to
address the complete utilization of steel slag.
ACKNOWLEDGMENT
The authors are thankful to Tata Steel management for
their encouragement and permission to publish this paper.
SKT would like to thank the Natural Resources Research
Institute (NRRI), UMD, for allowing me to present the
paper at IMPC.
REFERENCES
Alanyalı, H., Çöl, M., Yılmaz, M., &Karagöz, Ş. (2006).
Application of magnetic separation to steelmaking
slags for reclamation. Waste Management, 26(10),
1133–1139.
Ashrit, S., Sarkar, S., Chatti, R. V., Sarkar, C., &Sarkar,
S. (2020). Nonmetallic LD slag fines–opportunities by
invoking chemistry. Ironmaking &Steelmaking, 47(8),
903–907.
Aziz, M. M. A., Hainin, M. R., Yaacob, H., Ali, Z., Chang,
F. L., &Adnan, A. M. (2014). Characterisation and
utilisation of steel slag for the construction of roads and
highways. Materials Research Innovations, 18(sup6),
S6-255.
Han, Z., Wu, Y., Yu, H., &Zhou, S. (2022). Location-
dependent effect of nickel on hydrogen dissociation
and diffusion on Mg (0001) surface: Insights into
hydrogen storage material design. Journal of Magnesium
and Alloys, 10(6), 1617–1630.
Iwasaki, I., Fregeau-Wu, E., &Fujita, T. (1993). Removal
of phosphorus from steelmaking slags: a literature
survey. Mineral Procesing and Extractive Metallurgy
Review, 12(1), 19–36.
Jiang, Y., Ling, T. C., Shi, C., &Pan, S. Y. (2018).
Characteristics of steel slags and their use in cement
and concrete—A review. Resources, Conservation and
Recycling, 136, 187–197.
Li, J., Wu, B., Zhou, T., &Chai, X. (2018). Preferential
removal of phosphorus using modified steel slag and
cement combination for its implications in engi-
neering applications. Environmental Technology &
Innovation, 10, 264–274.
LIMS, Product Profile, Eriez Magnetics, https://www
.eriez.com/NA/EN/Products/Magnetic-Separation
/Permanent-Magnets/Drum-Separators.htm (page
accessed on 22nd May 2024).
Further, 17% of the particles are below 0.106 mm
in the slag.
• XRD analysis of the slag samples concluded that
Calcium-bearing silicates are the major phases
(Brownmillerite, Hatrurite, Brownmillerite (Mg,
Si-exchanged), Dicalcium Silicate -Alpha. Iron is
reported in Wuestite and Dicalcium Diiron(III)
Oxide as a major phase.
• Phase analysis in SEM-EDS indicated that iron is
segregated as Fe-metal, wustite, and interlocked
with magnesium oxide as well as with calcium sili-
cate at secondary phases. Phosphorous is found to
be concentrated on calcium silicate phases, whereas
alumina does not have any correlation. Further lib-
eration is necessary for the effective separation of
iron and Ca-bearing phases in the slag. However,
the exact liberation size of individual phases, along
with their volume, can be quantified by using MLA/
QEMSCAN.
• Similarly, magnetization studies were carried out and
concluded that the saturation magnetization value at
3 T is 3.1.
• Magnetic separation of as-received samples in
RERMS indicated the marginal efficiency in the
separation of iron-bearing minerals because of higher
magnetic field intensity over the roll surface. A maxi-
mum iron enrichment of 20.68% Fe(T) from 17.5%
was reported at a roll speed of 350rpm and splitter
position 3.
• In REDMS, at a drum speed of 90 rpm, iron was
found to be enriched up to 24.65 Fe(T) with a recov-
ery of 44.77% for the as-received sample.
• In a dry low-intensity magnetic separator, iron was
found to be enriched up to 29.6% Fe(T) in the
coarser size fractions of –3 mm at a drum speed of
42 rpm. Thus, the above findings suggest that multi-
stage magnetic separation using a low-intensity mag-
netic separator (LIMS) can be employed to maximize
the enrichment of iron-bearing phases from the slag.
• Magnetic fraction products can be utilized by recy-
cling into the secondary steel-making process or
through the sintering process, where the balance
between CaO and iron can be manipulated. Other
separation techniques can also be studied for better
decision-making.
• Similarly, the non-magnetic fraction products can
be studied for aggregate or cement industries to take
advantage of zero-carbon Ca-rich material with a
lower amount of iron, which will help in reducing
the overall fusion temperature of the clinker in the
cement manufacturing process. However, a detailed
study in this direction will be a way forward to
address the complete utilization of steel slag.
ACKNOWLEDGMENT
The authors are thankful to Tata Steel management for
their encouragement and permission to publish this paper.
SKT would like to thank the Natural Resources Research
Institute (NRRI), UMD, for allowing me to present the
paper at IMPC.
REFERENCES
Alanyalı, H., Çöl, M., Yılmaz, M., &Karagöz, Ş. (2006).
Application of magnetic separation to steelmaking
slags for reclamation. Waste Management, 26(10),
1133–1139.
Ashrit, S., Sarkar, S., Chatti, R. V., Sarkar, C., &Sarkar,
S. (2020). Nonmetallic LD slag fines–opportunities by
invoking chemistry. Ironmaking &Steelmaking, 47(8),
903–907.
Aziz, M. M. A., Hainin, M. R., Yaacob, H., Ali, Z., Chang,
F. L., &Adnan, A. M. (2014). Characterisation and
utilisation of steel slag for the construction of roads and
highways. Materials Research Innovations, 18(sup6),
S6-255.
Han, Z., Wu, Y., Yu, H., &Zhou, S. (2022). Location-
dependent effect of nickel on hydrogen dissociation
and diffusion on Mg (0001) surface: Insights into
hydrogen storage material design. Journal of Magnesium
and Alloys, 10(6), 1617–1630.
Iwasaki, I., Fregeau-Wu, E., &Fujita, T. (1993). Removal
of phosphorus from steelmaking slags: a literature
survey. Mineral Procesing and Extractive Metallurgy
Review, 12(1), 19–36.
Jiang, Y., Ling, T. C., Shi, C., &Pan, S. Y. (2018).
Characteristics of steel slags and their use in cement
and concrete—A review. Resources, Conservation and
Recycling, 136, 187–197.
Li, J., Wu, B., Zhou, T., &Chai, X. (2018). Preferential
removal of phosphorus using modified steel slag and
cement combination for its implications in engi-
neering applications. Environmental Technology &
Innovation, 10, 264–274.
LIMS, Product Profile, Eriez Magnetics, https://www
.eriez.com/NA/EN/Products/Magnetic-Separation
/Permanent-Magnets/Drum-Separators.htm (page
accessed on 22nd May 2024).