The document discusses various techniques for extracting copper from its ore. It begins by explaining that copper ore is mined either underground or via open-pit mining. It then describes different types of copper ores and various metallurgical processes used to extract copper, including hydrometallurgical, pyrometallurgical, and electromettalurgical techniques. Specific steps like concentration, roasting, smelting, and refining are outlined. The document also discusses extraction of precious metals from copper anode sludge and various alloys of copper along with their applications.
2. EXTRACTION TECHNIQUES FOR COPPER
• Copper ore is mined both underground and on the surface.
Large excavations formed by surface mining are called
open-pit mines.
• Most of the copper ores mined today are oxide or sulfide
ores.
• HYDROMETALLURGICAL operations are required for
treating very poor grade oxide ores (LEACHING)
• PYROMETALLURGICAL treatments are given to the
sulphide ores for their smelting and roasting.
• ELECTROMETALLURGICAL techniques are employed
for the electro refining of blister copper or copper scrap.
3. EXTRACTION OF COPPER FROM
SULPHIDE ORES
• Copper is extracted usually from the sulphide ore
chalcopyrite (CuFeS2) by smelting process.
• Ores containing 4% or more copper are treated by smelting
process.
• There are following steps for the Pyrometallurgical
extraction of copper from Chalcopyrite.
1. CONCENTRATION
2. ROASTING
3. SMELTING
4. BESSEMERIZATION
4. CONCENTRATION BY FROTH
FLOTATION
“Crushed ore is suspended in water containing pine
oil. The pine oil binds to the copper compounds, but
not to the unwanted rocky material. A blast of air is
passed through the suspension. The particles of ore
get wetted by oil and floats as a froth which is
skimmed. The gangue sinks to the bottom.”
5. ROASTING
The concentrated ore is roasted in the furnace in the
presence of oxygen. Sulphur is oxidized to SO2 and
impurities of arsenic and antimony are removed as
volatile oxides. The following reactions take place:
2CuFeS2 + O2
S + O2
4As + 3O2
4Sb + 3O2
Cu2S + O2
FeS + O2
Cu2S + 2FeS + SO2
SO2
2As2O3
2Sb2O3
Cu2O + SO2
FeO + SO2
6. SMELTING
The roasted ore is mixed with coke and silica sand (SiO2) and is
introduced into a blast furnace. The hot air is blasted and FeO is
converted into ferrous silicate (FeSiO3)
FeO + SiO2
Cu2O + FeS
FeSiO3
Cu2S + FeO
FeSiO3 (slag) floats over the molten matte of copper.
The resulting product of smelting is the combination of copper sulfate
and iron sulfide called matte (Copper matte).
7. BESSEMERIZATION
Copper metal is extracted from molten
matte through bessemerization . The
matte is introduced in to Bessemer
converter which uphold by tuyeres. The
air is blown through the molten matte.
Blast of air converts Cu2S partly into
Cu2O which reacts with remaining
Cu2S to give molten copper.
2Cu2S + 3O2
2Cu2O + Cu2S
2Cu2O + 2SO2
6Cu + SO2
8. BLISTER COPPER
The product of Bessemerization is called as “Blister
Copper” because, as it solidifies, SO2 hidden in it
escapes out producing blister on its surface.
9. REFINING OF BLISTER COPPER
• Blister copper is refined by electrolysis. The blister copper then
undergoes "fire refining.“
• Air and natural gas are blown through the copper to remove any
remaining sulfur and oxygen.
• The copper is cast into copper anodes and placed in an electrolytic
cell. Once charged, the pure copper collects on the cathode and is
removed as 99% pure.
• Blocks of blister copper are used as anodes and thin sheets of pure
copper act as cathodes. The cathode plates are coated with graphite
in order to remove depositing copper.
• The electrolyte is copper sulphate (CuSO4) mixed with a little
amount of H2SO4 to increase the electrical conductivity.
• Optimum potential difference is 1.3 volt for this electrolytic
process.
10. ELECTROLYTIC TANK FOR REFINING
Cu
Cu+2+2e-
Cu+2+2e-
Cu
Fe(s) → Fe2+(aq) + 2e–
Zn(s) → Zn2+(aq) + 2e–
11. EXTRACTION OF PRECIOUS METALS
FROM ANODE SLUDGE
Impurities, such as Ag, Au, and Pt, are less easily oxidized than
Cu. These remain in metallic form and fall to the bottom of the
cell, forming “anode sludge” from which they can later be
recovered. The anode sludges from copper-refining cells provide
one fourth of U.S. silver production and about one eighth of U.S.
gold production.
14. CLASSIFICATION OF COPPER ALLOYS
There are five different classification of copper alloys
1)Unalloyed
Copper
2)Brasses
Copper – Zinc alloys
Copper – Lead alloys
Copper – Zinc alloys with
Tin and Aluminium
additions
3)Bronze
• Copper – Tin alloys
• Copper – Aluminiumalloys
• Copper – Silicon alloys
• Copper – Beryllium alloys
4) Cu-Ni
based
• Cupronickel (Cu-
Ni)
• Nickel silver (Cu-
Ni-Zn
5) Nickel
silver
15. 1)UNALLOYED COPPER
• Copper content > 99.3%
Roughly classify into three categories
• Electrolytic tough pitch
This copper contains 99.9% Cu
with 0.045 O content
• Oxygen – free
Oxygen-free copper is produced
from electrorefined cathode copper which is melt and cast in
a reducing atmosphere of CO and N to prevent O.
• Phosphorus deoxidized
Phosphorus is sufficiently added
to produce phosphoruspentoxide P2O5
16. 2) BRASS:
There are two Class of brass
• The alpha alloys
with less than 37% Zinc.
These alloys are ductile and
can be cold worked.
• The alpha/beta or duplex
alloys
with 37-45% Zinc. These
alloys have limited cold
ductility and are typically
harder and stronger
• Families of Brass
• Cast alloy brasses
• Copper-Tin-Zinc alloys (red, semi-red
and yellow brasses)
• Cast Copper-Bismuth and Copper-
Bismuth-Selenium alloys.
• Copper-Zinc-Silicon alloys (Silicon
brasses and bronzes)
• wrought alloy brasses
• Copper-Zinc alloys
• Copper-Zinc-Tin alloys (Tin brasses)
• Copper-Zinc-Lead alloys (Leaded
brasses)
23. TIN BRONZES
• Alloys of copper and tin
• Other Alloying Elements may also be present With
The Exception of Zinc
• Also called Phosphor bronzes
• Phosphorus content (0.01-0.5%)
• Tin Content (1-11%)
• High corrosion resistance , Toughness ,Low
coefficient of friction, free from seasonal cracking
24. SILICON BRONZES
• Alloys of Copper And Silicon
• Maximum Solubility In Alpha Phase is 5.3 and decrease with
the temperature
• Alloys contains less than 5% Si are single Phased
• These are the Strongest of the work hard enable Copper
Alloys
• Their Mechanical Properties are comparable to mild steel and
corrosion resistance is comparable to copper
• These are used for Tanks , pressure vessels , Marine
construction , hydrulic preassure lines
25. ALUMINUM BRONZE
• Alloys of Al & Cu
• Maximum solubility of Al in α-solid solution is 9.5%
• Commercial Al bronzes contain (4-11%)Al
• Alloys containing up to 7.5% al are single phase, other are
double phase
• Other elements are also added intentionally e-g , Fe , Mn , Si
, Ni
• Iron Increases strength , silicon improves machinability , Mn
improves sound casting
• Single phase Bronze show good cold working propertis along
with high corrosion resistance to water and atomsphere
• These are used for water condenser tubes,nuts , bolts,
corrosion resistance vessels ,and in marine application
26. BERYLLIUM BRONZES
• Alloys of Cu & Beryllium
• Maximum solubility in Alpha solid Solution is 2.1 % and
decreases to 0.25 % to room temperature
• It is increased by age hardening
• They have excellent formability ,high tensile strength , creep
resistance , high electrical conductivity
• These are used in diaphrames , surgical instrument ,bolts &
screws , firing pins , dies.
27. CUPRO NICKELS
• Alloys of Cu & Ni , contains upto 30 % Ni
• Cupronickels Alloys are single phase alloys
• No heat treatment is required
• Properties are improved only by cold working
• They have high fatigue resistance , high corrosion &
erosion resistance toward sea water
• These are widely used in condenser , heat exchanger
tubes , coastal power plants
28. NICKEL SILVER
• Alloys of Cu-Ni-Zn
• Commercial Alloys are contain Cu (50-70%) , Ni (5-10%) , Zn
(5-40%)
• If copper is more than 60 % these are single phased ,ductile &
easily workable at room temp.
• Addition of Zinc imparts silver-blue-white colour ,good
corrosion resistance.
• These are Excellent base metals for plating with Cr ,Ni ,Ag
• These are used For Rivets, screws, Costume jewelry , name
plates & radio dials
29. COPPER AND COPPER ALLOYS
APPLICATIONS
ELECTRICAL APPLICATIONS
Approximately 65% of copper produced is used for electrical applications.
Power generation and transmission
generators, transformers, motors, busbars and cables provide and
deliverelectricity safely and efficiently to homes and businesses.
Electrical equipment - providing circuitry, wiring and contacts for PCs,
TVs and mobile phones.
30. Copper is used in the manufacturing of heatsinks.
In a microchip, copper is commonly used for what is known as the
'global interconnects' because of its good conductivity. These are the
wires that connect different sections of the chip together.
Cu-Ni 70-30 alloy is used in steam generators, heat exchangers,
coolers, condensers, tanks, pipework, valves and fittings in
electricity generation by Nuclear means
31. CONSTRUCTION APPLICATIONS
,
25% of all the copper produced is used in
buildings.
The skin of STATUE Of LIBERTY is made
of 81.3 tones Cu.
Cu is used in roofs, flashings, gutters, downspouts
domes, spires, vaults, wall cladding and building
expansion joints.
32. TRANSPORT APPLICATIONS
Transport accounts for 7% of copper usage.
NUCLEAR WASTE is enclosed
in these containers having Cu
shell on it.
33. Automotives radiator is made of copper-brass
alloy.
MEDICALAPPLICATIONS
Bacteria will not grow on cu surface b/c it is BIOSTATIC.
Cu doorknobs are used by hospitals to reduce the transfer of
diseases.
LEGIONNAIRE’S disease is suppressed by Cu tubing in air
conditioning system.
Copper's naturally antimicrobial properties can be exploited in
hygienic surfaces for hospitals and healthcare facilities.
CuSO4 is used as a fungicides and as algae control in domestic
35. COMMON APPLICATIONS
The remaining 3% is used for coins, sculptures, musical instruments
and cookware.
Cu-alloy is used in Bullets making.
One eurocent coin:
94.35% steel
5.65% copper
10 eurocent coin:
89% copper
5% aluminium
5% zinc
1% tin
PKR 5:
Cupro Nikle alloys