Meaning of Cobalt Ore's of Cobalt Uses of Cobalt Extraction of Cobalt Chemical Properties of Cobalt Physical Properties of Cobalt

1. COBALT

2. COBALT
• The word cobalt, from the German
word Kobold , meaning "goblin" or "evil
spirit," was used by miners to describe a
mineral that was very difficult to mine
and was damaging to their health.• Cobalt is a relatively abundant
element at about 10 to 30 parts per
million. This places it in the upper
third of elements according to their
abundance in the Earth's crust.• Cobalt is primarily used as the metal,
in the preparation of magnetic,
wear-resistant and high-
strength alloys.
• George Brandt discovered cobalt in 1735.

3. SOURCES OF COBALT
• sulfidiccobaltite (CoAsS)
• safflorite (CoAs2)
• glaucodot ((Co,Fe)AsS)
• skutterudite (CoAs3)
• pink erythrite ("cobalt glance": Co3(AsO4)2·8H2O)
• spherocobaltite (CoCO3)
• Smaltite (Co,Ni)As3
• Chloranthite (CuSO4 · 5H2O)
• Linnaeite (Co+2Co+3
2S4 )

4. safflorite (CoA
s2)
sulfidiccobaltite (Co
AsS)
glaucodot ((Co,Fe)
AsS)
skutterudite (Co
As3)
pink erythrite (Co3(AsO4)2·8H2O)spherocobaltite (CoCO3)Smaltite (Co,Ni)As3Chloranthite (CuSO4 · 5H

5. PHYSICAL PROPERTIES
• A lustrous, silvery-blue metal. It is magnetic.
• Boiling point 2927 °C
• Density 8.9 g.cm-3 at 20°C
• Melting point 1495 °C
• It is a brittle, hard metal.
• It has a metallic permeability of
about two thirds that of iron.

6. CHEMICAL PROPERTIES
• Cobalt is a moderately reactive element.
• It does not react with water at room
temperatures.
• It reacts with most acids to produce hydrogen gas.
• It combines slowly with oxygen in the air, but does not catch fire
and burn unless it is in a powder form.

7. ALLOYS
• Alacrite
 It was "originally developed for use in aircraft."
 This particular alloy is composed
primarily of cobalt, with the
remaining elements being 20%
chromium, 15% tungsten, 10% nickel
and 0.1% carbon. Its density is
9150 kg/m3.• Vitallium
 is a trademark for an alloy of 65% cobalt,
30% chromium, 5% molybdenum, and other
substances
 The alloy is used in dentistry,
artificial joints and turbocharges
because of its resistance to corrosion
and heat.

8. • Cobalt-chrome or cobalt-
chromium (CoCr) a metal alloy of cobalt and chromium.
 Cobalt-chrome has a very
high specific strength and is
commonly used in gas
turbines, dental implants,
and orthopedic implants.• Megallium
 is a trademark for an alloy of
60% cobalt, 20% chromium,
5% molybdenum, and traces of other
substances The alloy is used in dentistry because
of its light weight, resistance
to corrosion and hypo-
allergenic (nickel free) properties. developed by John Leonard
Attenborough for Attenborough
Dental Laboratories in 1951.

9. • Permendur
 is a cobalt-iron soft
magnetic alloy with equal parts of
cobalt and iron . Standard permendur compositions
coined Fe-Co 50/50 or 50Fe-50Co may
contain carbon up to 1%
 The alloy was invented in the United States around 1920.
• Pobedit
 is a sintered carbide alloy of about
90% tungsten carbide as a hard
phase, and about 10% cobalt (Co) as
a binder phase, with a small amount
of additional carbon.Pobedit is close in hardness
to diamond (85-90 on the Rockwell
scale).

10. • Samarium–cobalt (SmCo)
a type of rare earth magnet, is a
strong permanent magnet made of
an alloy of samarium and cobalt.
 They are brittle, and prone to cracking
and chipping.
 They were developed in the early
1970s by Albert Gale and Dilip K.
Das of Raytheon Corporation.
• Stellite
alloy is a range of cobalt-chromium
alloys designed for wear resistance
 It may also
contain tungsten or molybdenum and a
small but important amount of carbon

11. EXTRACTION OF COBALT
• Recovery from copper-cobalt sulfide concentrates
The ores are treated by a sulfurizing roast in a fluidized
bed furnace to convert copper and cobalt sulfides into
soluble oxides and iron into insoluble hematite. The calcine is
subsequently leached with sulfuric acid from the spent copper
recovery electrolyte. Oxide concentrates are introduced at this
leaching step to maintain the acid balance in the circuit. Iron
and aluminum are removed from the leach solution by the
addition of lime, and copper cathodes.

12. • Recovery from nickel-cobalt sulfide concentrates (Sherritt
process)
The Sherritt process is a hydrometallurgical process named
for Sherritt Gordon Mines Ltd for the recovery of copper and
nickel. Nickel sulfide concentrates can be treated by either
roasting or flash smelting to produce matte from which nickel
and cobalt can be recovered hydrometallurgically, or they may
be treated by an ammonia solution pressure leach.

13. • Recovery from nickel-cobalt sulfide concentrates
(Sherritt process)
A feed of matte and sulfide concentrate containing
approximately 0.4% cobalt and 30% sulfur is pressure
leached at elevated temperature and pressure in an
ammoniacal solution to produce a solution of nickel, copper
and cobalt. By boiling away the ammonia; copper is
precipitated as a sulfide and sent to a smelter. Hydrogen
sulfide is added to the autoclave to remove nickel sulfide
and copper sulfide which is fed back to the leaching process.
Air is then passed through the solution in the autoclave for
oxyhydrolysis. The solution is then reduced with hydrogen,
again at high temperature and pressure, to precipitate nickel
powder (>99%).

14. • Recovery from nickel-cobalt sulfide concentrates (Sherritt
process)
The remaining solution is then adjusted to precipitate
the mixed sulfides and the fluid is concentrated and
crystallized into ammonium sulfate ((NH4)2SO4). The
mixed sulfides are pressure leached with air and sulfuric
acid. Ammonia is then added to remove potassium and
iron as jarosite (K𝐹𝑒3+3 (OH)6(SO4)2). The solution is
removed from the autoclave and sulfuric acid added to
remove nickel as nickel(II) sulfate-ammonium
sulfate hexahydrate ((NiSO4)•((NH4)2SO4)•6H2O) which is
then sent to have its nickel recovered. Addition of
hydrogen gas to saturation precipitates cobalt powder
with a purity of approximately 99.6%.

16. • Recovery from copper-cobalt oxide concentrates
For copper-cobalt ores, a sulfide concentrate is roasted under
controlled conditions to transform most of the cobalt sulfide to a
soluble sulfate while minimizing the change of copper and iron to
their water-soluble states. The product is leached, the resulting
solution is treated to remove copper and iron, and the cobalt is finally
recovered by electrolysis. If the copper and cobalt ores are in the
oxidized state, copper can be removed by electrolysis in sulfuric acid
solution and the cobalt precipitated from the spent electrolyte by
adjustment of the acidity of the solution

17. • Recovery from laterite ores
Nickel-cobalt lateritic ores can be treated by either
hydrometallurgical processes or pyrometallurgical processes,
such as matte or ferronickel smelting, which require the entire
ore to be melted and the metal values to be separated from the
residual components of the ore. The hydrometallurgical process
for laterite ore can use sulfuric acid or ammonia leach solutions.

18. • Recovery from arsenide ores
Cobalt concentrates from arsenide ores may be roasted in the same
manner as sulfide concentrates in order to remove arsenic as an
impure arsenic trioxide (𝐴𝑠2 𝑂3). Alternatively they can be leached and
cobalt precipitated with hydrogen, as with nickel sulfide concentrates.

19. • Electrorefining
Electrorefining was performed in the electrolyser. It consist of 4
parts: a resort, a transitional chamber, a lid, and a furnace with
resistive heating. The electrolyte and the metal to be refined, in a
plate-holder provided with a diaphragm, were loaded into
crucible. Temperatures were obtained using thermocouple. The
cathode, on the current lead, after conducting a known amount of
electricity was slowly lifted from the electrolyte to lock chamber to
cool. The hermetic damper overlapped the space between the lock
chamber and the retort to preserve the inert atmosphere over the
melt.

20. The cooling of the retort flange, transitional chamber, and lid
was performed in water to eliminate the destruction of the
vacuum padding and speed up the cathode cooling. After
changing the cathode the lock chamber was evacuated and filled
with inert gas and the damper was opened to immerse the
cathode in the melt. The luting nut served for fixing the cathode
position and sealing of the electrolyser An equimolar mixture of
NaCl-KCl containing 20% 𝐾2Ti𝐹6 was used as electrolyte.
• Electrorefining

21. 1. The current lead
2. Lock chamber
3. Cathode
4. Transition chamber
5. Retort
6. Furnace
7. Thermocouple
8. Luting Nut
9. Lid
10.Hermetic damper
11.Electrolyte
12.Diaphragm
13.Crucible

22. USES
• Cobalt, like iron, can be magnetized and so is used to make
magnets. It is alloyed with aluminum and nickel to make particularly
powerful magnets.• Other alloys of cobalt are used in jet turbines and gas turbine
generators, where high-temperature strength is important.
• Cobalt metal is sometimes used in electroplating because of its
attractive appearance, hardness and resistance to corrosion.
• Cobalt salts have been used for centuries to produce brilliant blue
colours in paint, porcelain, glass, pottery and enamels.
• Radioactive cobalt-60 is used to treat cancer and, in some countries,
to irradiate food to preserve it.