3. part of the boron group in the periodic table
third most abundant element in the Earth’s
crust
ability to resist corrosion due to passivation
capable of being a super conductor
almost never found in its elemental state
aluminum is found only in chemical
compounds with other elements
4. lightweight, strong, nonmagnetic, and
nontoxic
conducts heat and electricity and reflects heat
and light
strong but easily workable
aluminum can easily and economically be
recycled into new products
surface of aluminum quickly oxidizes to form
an invisible barrier to corrosion
5.
6. potters made their strongest vessels from
clay that contained aluminum oxide
aluminum compounds in fabric dyes,
cosmetics, and medicines
7. Bauxite is most useful for producing pure
aluminum
consists of 45-60% aluminum oxide
4 lb (2 kg) of bauxite to produce 1 lb (0.5 kg)
of aluminum metal
Caustic soda is used to dissolve the
aluminum compounds
8. the Bayer process and Hall-Heroult process
Cryolite used as the electrolyte in smelting
Aluminum fluoride is added to lower the
melting point of the electrolyte solution
Carbon electrodes transmit the electric
current through the electrolyte
production of 2 lb (1 kg) of aluminum
requires 15 kilowatt-hours (kWh) of energy
9. refining the bauxite ore to obtain aluminum
oxide
1. The bauxite ore is mechanically crushed
2. It is mixed with caustic soda and processed
into a slurry
3. The slurry is pumped into a digester
4. It is passed through a series of flash tanks
that reduce the pressure
5. The slurry is pumped into a settling tank
10. 6. The remaining liquid is pumped through
cloth filters
7. The filtered liquid is pumped through a
series of precipitation tanks
8. Seed crystals of alumina hydrate are added
9. The crystals precipitate and are removed.
10. After washing, they are transferred to a kiln
for calcining.
11. After leaving the kiln, the crystals pass
through a cooler.
11. process of smelting the aluminum oxide to
release pure aluminum
12. Smelting of alumina into metallic aluminum
takes place in a steel vat called a reduction
pot
13. Within the reduction pot, alumina crystals
are dissolved in molten cryolite at a
temperature of 1,760-1,780° F (960-970° C)
12. 14. A crucible is moved down the potline,
collecting molten aluminum, which is 99.8%
pure
15. The metal is transferred to a holding
furnace and then cast as ingots
13. Alumina is used in laundry detergents,
toothpaste, and fluorescent light bulbs
Also an important ingredient in ceramic
materials
largest waste product generated in bauxite
refining is the tailings (red mud)
Aluminum plants in the United States create
significant amounts of greenhouse gases
14. Lightweight: a third of the weight of steel,
brass, or copper of equal volume
28. Aerospace: percentage in aircraft frames is
70%
Automotive: advantage of lightness,
resistance and recyclability
Marine: lightening hulls by 40% to 50% over
steel
Rail: lighter structures, resistance and
durability
29.
30. Building: commonly used in extruded, sheet-rolled
or molded forms
Packaging: modern packaging is one of the
leading consumers of aluminum
Mechanical Industry and Engineering:
aluminum parts can reduce inertia
HVAC exchangers and the plastics industry
31. Energy Distribution: low density and excellent
electrical conductivity
Sports and leisure
34. With very high thermal and electrical
conductivity
Soft, malleable, and has a reddish-orange
color
Ductile, non-magnetic, and corrosion
resistant
Melting point at 1981 F or 1083 C
35. Bronze Age (3500BC)
An alloy of copper and tin
Used to make tools and weapons
36. Brass, a copper and zinc alloy
Used in decoration and later, weapons
49. most common source are sulfide ores
most common sulfide ore is chalcopyrite
50. varies according to type of ore and desired
purity
unwanted materials are physically or
chemically removed
concentration of copper is progressively
increased
51. 1. sulfide ores are taken from huge open-pit
mines
2. material located above the ore is called
overburden
3. exposed ore is scooped up by large power
shovels
52. 1. ore is crushed in a series of cone crushers
2. crushed ore is ground even smaller by mills
3. mixed with water and placed in a rod mill
4. mixture is further broken up in ball mills
5. slurry mixed with various chemical reagents
6. A liquid, called a frother, is also added
7. mixture pumped into flotation cells
8. copper particles cling to bubbles as they
rise
53. 1. concentrate is fed into a furnace along with
a silica material, flux
2. concentrate and flux melt and collect in the
bottom
3. iron chemically combines with flux to form
slag
4. sulfur combines with the oxygen to form
sulfur dioxide
54. 5. molten material in the bottom is called the
matte
6. molten matte is drawn and poured into a
converter
7. resulting molten material is called the
blister
55. 1. blister copper is heated in a refining furnace
2. poured into molds to form electrical anodes
3. copper anode is placed in an individual tank
4. sheet of copper is placed on the opposite
end
5. tanks are filled with an acidic copper
sulfate solution
6. electrical current is passed through each
tank
56. 7. copper is stripped off the anode and
deposits on the cathode
8. After 9-15 days, the current is turned off
9. Copper is cast into ingots, rolls, etc.
57. sulfuric acid
Gold, silver, and other precious metals
overburden, tailings and slag