2. INTRODUCTION
ïMagnetic separators are used to separate
either valuable minerals from non-magnetic
gangue, e.g. magnetite from
quartz, or magnetic contaminants
ïOr other valuable minerals from the non-
magnetic values.
ïAll materials are affected in some way when
placed in a magnetic field, although with most
substances the effect is too slight to be
detected.
3. ï Materials can be classified into two groups.
1. Diamagnetic Materials
2. Paramagnetic Materials
ïDiamagnetic are repelled along the lines of magnetic
force to a point where the field intensity is smaller.
ïThe forces involved here are very small.
ïParamagnetic are attracted along the lines of
magnetic force to points of greater field intensity.
ïExamples of paramagnetic are ilmenite
(FeTiO3), pyrrhotite (FeS), and manganese minerals.
ïSome elements are themselves paramagnetic, such
as Ni, Co, Mn , Cr and Pt.
ïThe paramagnetic properties of minerals are due to
the presence of iron in some
4.
5. APPLICATION OF MAGNETISM AS SEPARATOR
1. For the removal of tramp iron in coarse and
intermediate- crushing circuits, as a protection to
the crushing machinery.
2. For the concentration of magnetite ores.
3. For the concentration of iron ore other than
magnetite, after preliminary conversion of iron
minerals to artificial magnetite by suitable
Roasting.
4. For the removal of small quantities of iron ore
minerals from Ceramic raw materials.
6. ELEMENTS OF DESIGN OF MAGNETIC SEPARATORS
1. Production of suitably converging magnetic field.
2. Even feeding of ore particles as a stream or sheet.
3. Control of speed of passage of ore through the
magnetic field.
4. Avoidance and / or correction of occlusion or non
magnetic material between or within magnetic
flux.
5. Provision of suitable means for disposing of
separated products.
6. Provision for production of a middling.
7. Elimination or reduction to a minimum of moving
(wearing ) parts.
7. CLASSIFICATION OF MAGNETIC SEPARATOR
It can be classified according to the medium in which
the separation is made, the mode of the presentation
of the feed, the mode of disposal of the products, &
whether the magnets are stationary or moving.
8. IMPORTANT TYPES OF MAGNETIC SEPARATOR
1. EDISON SEPARATOR
2. BALL NORTON SEPARATOR
3. MAGNETIC DRUM SEPARATOR
4. ROLLAR TYPE SEPATOR
5. GRAVITY FEED MAGNETIC SEPARATOR
6. MAGNETIC COOLENT SEPARATOR
7. WET DRUM SEPRATOR
9. EDISON SEPARATOR
Edison separator consists of a bar
magnet . The ore as thin streams falls
in front of the poles, susceptible
particles being deflected inwards &
nonsusceptible particles continuing
to fall undeflected.
This separator was not wholly
successful because of inability of
control flow of solid in a thin
sheet, & because of lack of control
over the speed of the falling
particles.
11. Magnetic drum separators are important
magnetic separators that removes ferrous metal
from dry bulk products in free-flowing
processing systems. They are self cleaning unit
consisting of drums and housing normally of
stainless steel. The magnets used by the
magnetic drum separators are either ceramic
magnets or rare earth magnets. The magnetic
drum separators are available both in single or
double drum configuration.
12. How it Works?
The processing materials enters the top of the magnetic
drum separator and flows across the surface of the drum.
The rotatory drum in the magnetic field captures the
ferrous tramps whereas non ferrous falls free from the
drum into the cleaned material flow. As the drum
rotates, the ferrous metal so captured is carried past the
diverter and released outside of the magnetic field.
Types
Magnetic drum separators are of different types like:
âąElectro drum separators
âąWet drum separators
Double drum separators
13. Applications
The magnetic drum separator is ideal for separating iron particles from
granules & powders It is widely used in the following industries:
âąGlass
âąCeramic
âąChemical
âąFertilizer
âąPlastic
âąFood industry
âąIron and steel slag treatment
âąReduced pyrite ash separation
âąCalcined ilmenite production
Metal powder production
14. Ball Norton Separator
Unlike most magnetic separators which are used to remove relatively
small amounts of metal, the Ball Norton Separator is designed to
handle large amounts of ferrous material - removing other
undesirable elements. A unique combination of alternating
magnetic poles and vibratory conveying works to clean the magnetic
material. Applications include foundry shot, crushed borings, slag
and magnetic ores.
15. How it Works?
The material is discharge on the belt by the feeder. The magnetic roll
is enveloped by the conveyor. The para and ferro magnetic
ingredients remains stuck to the belt whereas non magnetic
ingredients passes freely at the end of the conveyor.
Roller type magnetic separator is
meant to separate ferrous contaminants
from the flimsy magnetized dry
granular metallic and nonmetallic
materials. Roller type magnetic
separator has wide application in
industries and mineral technology. The
separator uses high powered rare earth
magnets with very low dimensional
tolerance. The other components of the
machine are conveyor and vibratory
feeder. The magnetic rolls are available
in different widths and magnetic
strength
16. Applications
Roller type magnetic separator finds applications in the following areas
like:
âąGlass industries
âąAbrasive refractory
âąQuartz cleaning
âąUpgrading of graphite
âąRecovery of metals from slag removal of ferro silicates
âąChemical industries
17. Gravity feed magnets separates ferrous tramp metal
through gravity system. These magnets are constructed
out of welded stainless steel and are available in stainless
steel structure. The gravity magnet comes in different
shapes and sizes and are ideal for narrow chute
applications. Gravity feed magnets are normally used in
vertical flow system.
18. Applications
Gravity magnetic separators have different industrial and commercial
usage. They are applied in industries like:
âąFood industry
âąChemical industry
âąGrain processing industries
Pharmaceutical industries
19. MAGNETIC COOLENT SEPARATOR
Magnetic coolant separator is a
device which cleans the coolant
liquid of very fine ferrous particles.
It removes the iron chips from the
milling or grinding liquid. It is light
and compact structure having
strong magnetic power which can
remove very fine ferrous particles.
For precise grinding operations
uninterrupted flow of oil is must.
The coolant magnetic separator
ensures the uninterrupted flow of
the liquid.
21. Features
ï± Wet drum magnets have high magnetic recovery and
discharge.
ï± The feed slurries recover the magnetics.
ï± Available in single or multiple drum applications.
ï± Recover magnetic solids in as clean a magnetic
concentrate as possible .
ï± Permanent magnet assembly eliminates coil burn-outs .
ï± The magnet / pole elements are bolted to a mild steel
shaft.
ï± The drum is made from thick stainless steel for long
service life.
ï± Wet drum separators are available in different
configuration like single drum,double drum and multiple
drum. In double drum two separators are arranged back
to back with a common feed back.
22. Applications
ï± Glass industry
ï± Chemical industry
ï± Plastic industry
ï± Mining industry
ï± Food industry
ï± Pharmaceuticals industry
ï± Foundry industry