XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 519
fraction from the metal recovery plant. The collected sam-
ples were subjected to different characterisation studies and
magnetic separation studies. The details of these studies are
described further in the next section.
Methods
Characterization Studies
The collected samples were subjected to different char-
acterisation studies, which include particle size analysis,
chemical analysis, density analysis, sink and float analysis,
phase analysis using Scanning Electron Microscopy-Energy
Dispersive Spectroscopy (SEM-EDS), X-ray diffraction
(XRD) analysis, magnetisation studies using vibratory
sample magnetometer (VSM), and sink-float studies using
heavy density liquids.
Particle size analysis was carried out in a Rotap ® sieve
shaker as per the IS standards (ISO 2591–1:1988 and ISO
565:1990) in dry and wet modes (for sizes 1 mm). Chemical
analysis of the slag sample was carried out by ICP and wet
gravimetric methods. (ICP-AES), supplied by Integra XL,
IR Tech. Pvt. Ltd, GBC Scientific Equipment, Victoria,
Australia). The metal analysis in the sample is found to be
critical, and Fe-metal and free lime are analysed using the
wet gravimetric method.
Sink and float studies were carried out for the BOF slag
sample by using commercial-grade heavy liquids (bromo-
form with a density of 2.81 g/cc and di-iodo-methane with
a density of 3.31 g/cc). The sink and float products were
analyzed further for interpretation. The slag was analysed
using X-ray diffraction (XRD) supplied by PANanalytical
B.V. (Malvern Panalytical, Almelo, The Netherlands), and
the major peaks were interpreted using the inbuilt ICDD
database.
The magnetization property of the slag was measured
using a Vibratory Sample Magnetometer (VSM) sup-
plied by Lake Shore Cryotronics, Inc., Canada. The hys-
teresis curve was plotted and analysed further. The phase
analysis of the slag was carried out in a Scanning Electron
Microscopy-Energy Dispersive Spectroscopy (SEM-EDS).
Model- Quanta 650F, supplied by FEI (The Netherlands).
Magnetic Separation Studies
Dry low-intensity magnetic separator. Experiments
were conducted in a dry low-intensity magnetic separa-
tor (DLIMS) (supplied by Eriez Magnetics, Model: Lab/
A-Type) to separate the presence of magnetic phases or
other iron-bearing minerals from the slag. It consists of a
permanent magnetic stainless-steel drum of 310 mm diam-
eter, and the maximum magnetic field intensity over the
surface is 1200 Gauss. The process width of the drum is
300 mm with a fixed feed receiving area of 55 cm. A vari-
able splitter is attached near the drum surface, whose posi-
tion can be varied between –450 to +450, to separate the
magnetic and non-magnetic fractions. It also consists of a
vibrating mechanism for particle flow in either single or
multiple layers. These parameters affect the enrichment in
the quality of the products obtained.
About 10 Kg of material, as received and –3 mm, were
prepared for the experimental study at different drum speeds
(6, 13, 24, 36, and 48 rpm). The feed rate (controlled by
vibration per cent) and splitter position were fixed at 21%
and –250, respectively. The feed was introduced on the
drum surface by controlling the operating parameters, and
the products obtained were analysed for characterisation.
Further, a few experiments were carried out on the same
equipment by varying the drum speed and splitter position
at multiple stages of separation. The details about the dry
LIMS and the principle of separation are well described in
the literature (LIMS, 2024).
Rare Earth Drum Magnetic Separator (REDMS).
Experiments were carried out in a pilot-scale REDMS
made by Outokumpu, Finland. This is a permanent mag-
netic separator with a magnetic field intensity of 7000
Gauss (maximum at drum surface). The drum speed of the
machine varied from 50 to 90 rpm by keeping other vari-
ables (Feed rate: 120 Kg/h. and splitter position (+1)) con-
stant. The separator was switched on to start after keeping
the variable at the desired level, and this was allowed to run
till the feed (10 Kg.) was exhausted. Magnetic and non-
magnetic products were collected separately and analyzed
for grade and recovery. The details about REDMS and the
principle of separation are well described in the literature
(REDMS, 2024).
Rare Earth Roll Magnetic Separator (RERMS).
Experiments were carried out using a RERMS with a roll
diameter of 100 mm and a width of 300 mm (L/P10-30
model, Outotec make). The magnet consists of Nd-B-Fe
rare earth elements and a steel ratio maintained 4:1. The belt
is made up of graphite-impregnated Kevlar with a thickness
of 0.25 mm. This is a permanent magnetic separator with
a magnetic field intensity of 12000 Gauss (maximum at
the belt surface). The roll speed of the machine varied from
250 to 400 rpm by keeping other variables (Feed rate: 100
Kg/h. and splitter position at ‘0’. Magnetic, middling and
non-magnetic products were collected separately and ana-
lyzed for grade and recovery. The details about RERMS and
the principle of separation are well described in the litera-
ture (Tripathy, 2017 Tripathy, 2017a).
fraction from the metal recovery plant. The collected sam-
ples were subjected to different characterisation studies and
magnetic separation studies. The details of these studies are
described further in the next section.
Methods
Characterization Studies
The collected samples were subjected to different char-
acterisation studies, which include particle size analysis,
chemical analysis, density analysis, sink and float analysis,
phase analysis using Scanning Electron Microscopy-Energy
Dispersive Spectroscopy (SEM-EDS), X-ray diffraction
(XRD) analysis, magnetisation studies using vibratory
sample magnetometer (VSM), and sink-float studies using
heavy density liquids.
Particle size analysis was carried out in a Rotap ® sieve
shaker as per the IS standards (ISO 2591–1:1988 and ISO
565:1990) in dry and wet modes (for sizes 1 mm). Chemical
analysis of the slag sample was carried out by ICP and wet
gravimetric methods. (ICP-AES), supplied by Integra XL,
IR Tech. Pvt. Ltd, GBC Scientific Equipment, Victoria,
Australia). The metal analysis in the sample is found to be
critical, and Fe-metal and free lime are analysed using the
wet gravimetric method.
Sink and float studies were carried out for the BOF slag
sample by using commercial-grade heavy liquids (bromo-
form with a density of 2.81 g/cc and di-iodo-methane with
a density of 3.31 g/cc). The sink and float products were
analyzed further for interpretation. The slag was analysed
using X-ray diffraction (XRD) supplied by PANanalytical
B.V. (Malvern Panalytical, Almelo, The Netherlands), and
the major peaks were interpreted using the inbuilt ICDD
database.
The magnetization property of the slag was measured
using a Vibratory Sample Magnetometer (VSM) sup-
plied by Lake Shore Cryotronics, Inc., Canada. The hys-
teresis curve was plotted and analysed further. The phase
analysis of the slag was carried out in a Scanning Electron
Microscopy-Energy Dispersive Spectroscopy (SEM-EDS).
Model- Quanta 650F, supplied by FEI (The Netherlands).
Magnetic Separation Studies
Dry low-intensity magnetic separator. Experiments
were conducted in a dry low-intensity magnetic separa-
tor (DLIMS) (supplied by Eriez Magnetics, Model: Lab/
A-Type) to separate the presence of magnetic phases or
other iron-bearing minerals from the slag. It consists of a
permanent magnetic stainless-steel drum of 310 mm diam-
eter, and the maximum magnetic field intensity over the
surface is 1200 Gauss. The process width of the drum is
300 mm with a fixed feed receiving area of 55 cm. A vari-
able splitter is attached near the drum surface, whose posi-
tion can be varied between –450 to +450, to separate the
magnetic and non-magnetic fractions. It also consists of a
vibrating mechanism for particle flow in either single or
multiple layers. These parameters affect the enrichment in
the quality of the products obtained.
About 10 Kg of material, as received and –3 mm, were
prepared for the experimental study at different drum speeds
(6, 13, 24, 36, and 48 rpm). The feed rate (controlled by
vibration per cent) and splitter position were fixed at 21%
and –250, respectively. The feed was introduced on the
drum surface by controlling the operating parameters, and
the products obtained were analysed for characterisation.
Further, a few experiments were carried out on the same
equipment by varying the drum speed and splitter position
at multiple stages of separation. The details about the dry
LIMS and the principle of separation are well described in
the literature (LIMS, 2024).
Rare Earth Drum Magnetic Separator (REDMS).
Experiments were carried out in a pilot-scale REDMS
made by Outokumpu, Finland. This is a permanent mag-
netic separator with a magnetic field intensity of 7000
Gauss (maximum at drum surface). The drum speed of the
machine varied from 50 to 90 rpm by keeping other vari-
ables (Feed rate: 120 Kg/h. and splitter position (+1)) con-
stant. The separator was switched on to start after keeping
the variable at the desired level, and this was allowed to run
till the feed (10 Kg.) was exhausted. Magnetic and non-
magnetic products were collected separately and analyzed
for grade and recovery. The details about REDMS and the
principle of separation are well described in the literature
(REDMS, 2024).
Rare Earth Roll Magnetic Separator (RERMS).
Experiments were carried out using a RERMS with a roll
diameter of 100 mm and a width of 300 mm (L/P10-30
model, Outotec make). The magnet consists of Nd-B-Fe
rare earth elements and a steel ratio maintained 4:1. The belt
is made up of graphite-impregnated Kevlar with a thickness
of 0.25 mm. This is a permanent magnetic separator with
a magnetic field intensity of 12000 Gauss (maximum at
the belt surface). The roll speed of the machine varied from
250 to 400 rpm by keeping other variables (Feed rate: 100
Kg/h. and splitter position at ‘0’. Magnetic, middling and
non-magnetic products were collected separately and ana-
lyzed for grade and recovery. The details about RERMS and
the principle of separation are well described in the litera-
ture (Tripathy, 2017 Tripathy, 2017a).