these will help you to understand the process of magnetic separation. it will help in industries

1. By
Gulshad Ahmad
Department of Chemical & Polymer Engineering
University of Engineering & Technology Lahore (FSD Campus)

2.  Magnetic separation is a process in which
magnetically susceptible material is extracted
from a mixture using a magnetic force. This
separation technique can be useful in mining
iron as it is attracted to a magnet.
12/24/2018 2

3. 12/24/2018 3

4. Principle:
 Magnetic separation is technique used in
metallurgy for the concentration of ore
particles. The principle of this method is that
the magnetic ore particles can be separated
from non magnetic impurities (gangue) or vice
versa.
12/24/2018 4

5. 12/24/2018 5

6. Uses:
In general terms, magnetic separation methods are
used in several distinct processes:
 Magnetic filtration
- recovery of liquid ( the magnetizable solids are
discarded)
- recovery of magnetizable solids (liquid is
discarded)
12/24/2018 6

7.  Concentration of magnetizable compo
into the magnetic fraction and rejection of
“non-magnetic” waste.
 Concentration of non-ferrous metals
discarding the non-metallic components
mixture.
 It is also widely used to remove m
contaminants from plastics but not to sepa
plastics from each other.
12/24/2018 7

8.  Dry magnetic separation process.
 Wet magnetic separation process.
12/24/2018 8

9.  In a dry mode, coarse magnetic particles can
be recovered by a variety of high-intensity
magnetic separators
 Including induced magnetic roll , cross belt
separator , permanent magnet roll separator,
rare-earth drum separator and open-gradient
separator.
12/24/2018 9

10. 12/24/2018 10
Pulverizer

11.  The MagMill is a selective dry screening and magnetic separation process
that is integrated into the existing coal pulverizers to remove unwanted
coal constituents prior to combustion. The MagMill can reduce emissions
of mercury and/or sulfur, improve boiler performance by reducing ash
components that contribute to slagging and/or erosion, and reduce coal
costs by upgrading poor quality coals.
 Within a pulverizer, coal falls down a central feed pipe onto a rotating
table in the bottom portion of the pulverizer. As the table rotates, the coal is
slung radially outward and crushed as it passes underneath gigantic steel
tires which roll in grooves on the table. Hot air blown from underneath the
rotating table enters the grinding chamber through a gap at the outer
circumference of the rotating table. This hot air both dries the coal and
sweeps the fine particles released in the crushing upward to the classifier at
the top of the mill. Oversize particles are returned for additional grinding
and the fine particles are blown directly to the burners.
12/24/2018 11

12.  Because of their weight and hardness, the minerals in the
feed coal require more passes underneath the rollers than
does the relatively soft hydrocarbon component of the
coal. The minerals, therefore, become concentrated on
the grinding table.
 In the MagMill configuration a stream rich in these hard-
to-grind minerals such as iron pyrite is withdrawn
through the wall of the pulverizer to the magnetic
separator. Outside the pulverizer the material is
processed through mechanical and magnetic separators
to reject the minerals and to recover the carbon which is
returned to the mill for grinding to specification.
12/24/2018 12

13. APPLICATIONS
 In the removal of tramp iron from process
streams.
 Purification of numerous industrial minerals
such as glass sand, fluorspar, feldspar,
diamond and others, by removing fine strongly
magnetic impurities.
12/24/2018 13

14.  For magnetic separator to be successful, the
material should be pletely dry, which sometimes
involves an expansive heating stage.
 For particles smaller than a certain threshold size
(for instance 75 µm), the attractive electrostatic
and van der Waals forces will cause sticking and
the formation of aggregates. Selectivity of
separation can thus be severely affected.
12/24/2018 14

15.  Wet low intensity drum magnetic separation
(LIMS) are used to recover strongly magnetic
solids from a slurry feed.
12/24/2018 15

16. 12/24/2018 16

17. USES:
 As a magnetic filter to remove a single solid
component from a suspension.
 As a magnetic separator to remove unwanted
magnetic component from a mixture of
materials
 For a concentration of valuable weakly
magnetic materials from a mixture.
12/24/2018 17

18.  Magnetic filtration is used primarily for the
removal of fine particulates from dilute fluid
suspensions.
 Removal is carried out by passing suspensions
through a magnetized matrix, which leads to
the retention of particles throughout the
matrix. The fluid stream may be either liquid
or gas.
12/24/2018 18

19.  The process of magnetic filtration is analogous
to that of deep be filtration, the difference
being that an additional external force, namely
the magnetic force, contributes to the filtration
efficiency in magnetic filtration.
 The magnitude of the applied magnetic field is
dictated by the magnetic susceptibility of the
suspended solids.
12/24/2018 19