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ME411 - Materials Engineering Group Report on Copper and Aluminum Members: Asuncion, Atienza, Bacero, Calarion, Calicdan
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Engineering Materials
Background
History
Processing
Uses
Properties
Copper
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
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
potters made their strongest vessels from clay that contained aluminum oxide
aluminum compounds in fabric dyes, cosmetics, and medicines
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
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
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
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.
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)
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
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
Lightweight: a third of the weight of steel, brass, or copper of equal volume
Strength: can stand heavy pressures and loads
Electrical Conductivity: conductivity is twice of copper
Thermal Conductivity: can quickly spread heat in an even and quick manner
Non-toxic: makes it ideal for packing cooking material
Reflectivity: reflects light as well as other forms of radiant energy.
Ductility: it can be drawn into wires
Miscible: alloying it with metals make it more malleable, conductive, and resilient
Finishing: coatings and finishes can be used over it
Costing: cheap and economical
Recyclable: cheaper than newly mined and processed aluminum
Durability
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
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
Energy Distribution: low density and excellent electrical conductivity
Sports and leisure
CopperBackground
History
Processing
Uses
Properties
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
Bronze Age (3500BC)
An alloy of copper and tin
Used to make tools and weapons
Brass, a copper and zinc alloy
Used in decoration and later, weapons
Continued use of brass
Copper used as a conductor
Brass continued use in instruments
Copper in electrical applications
Copper in electronics
Excellent heat conductivity
Excellent electrical conductivity
Good corrosion resistance
Good biofouling resistance
Machinability
Retention of electrical and mechanical properties at cryogenic temperatures
Non-magnetic
Power transmission lines
Electrical wiring, cables and busbars
Spark plugs
Electrodes
Cooking utensils
Heat exchangers
Plumbing
Refrigeration tubing
Water-cooled copper crucibles
most common source are sulfide ores
most common sulfide ore is chalcopyrite
varies according to type of ore and desired purity
unwanted materials are physically or chemically removed
concentration of copper is progressively increased
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
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
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
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
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
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.
sulfuric acid
Gold, silver, and other precious metals
overburden, tailings and slag
http://www.madehow.com/Volume-4/Copper.html
http://www.azom.com/article.aspx?ArticleID=2856
http://www.chemistryexplained.com/elements/A-C/Aluminum.html
http://resources.schoolscience.co.uk/CDA/14-16/chemistry/copch0pg2.html
http://education.jlab.org/itselemental/ele029.html
http://www.madehow.com/Volume-5/Aluminum.html#ixzz398Y6sFuh
http://www.constellium.com/technology-center/aluminium-alloy-applications
http://www.buzzle.com/articles/aluminum-uses-of-aluminum.html