Transcript Slide 1

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Seminar
Chemical Methods for Electronic Wastes
Recovery
Gholamhossein Paniri
Supervisor: Professor H. S. Ghaziaskar
Department of Chemistry
Isfahan University of Technology
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Content

What is electronic wastes

Why E-Wastes are recycling

E-waste recycling steps

Methods of materials chemical recovery

Conclusions

References
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What is Electronic Waste?
Electronic Waste
E- Waste
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Why E-Waste Recycling???
Others 6%
CRT 12%
Plastics 33%
Metals 49%
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H.-Y. Kang, J.M. Schoenung / Resources, Conservation and Recycling 45 (2005)
Types material of E-Waste
precious metals
hazardous material
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Weight Percent of Metals in different Electronic Wastes
Electronic
waste scrap
Fe
Cu
Al
Pb
Zn
Ag
Au
Pd
PC
7
20
5
1.5
1
10
25
11
Mobile
Phone
5
13
1
0.3
0.1
13.8
35
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DVD
Player
23
5
2
0.3
0.05
11.5
1.5
4
Calculator
62
3
5
0.1
0.5
2.6
5
5
Printer
4.5
10
7
1.2
0.85
2.8
11
0
TV
0
3.4
1.2
0.2
0.038
0.29
0.12
3
CRT
28
10
10
1
0.3
0.28
0.2
0
J. Cui, L. Zhang / Journal of Hazardous Materials 158 (2008) 228–256
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Vi=
100 WtiPri
∑ WtiPri
Vi= Value distribution
Wti= Weight precent of metal i in the electronic scrap sample
Pri= the current price of metal i
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Value-Share (%)
Electronic
waste scrap
Fe
Cu
Al
Pb
Zn
Ag
Prices
($/ ton )
300
7736
2475
3580
31150
430000
PC
0
16
1
1
3
4
Mobile phone
0
8
0
0
0
DVD player
17
35
1
1
Calculator
1
12
0
Printer
1
19
TV
0
CRT
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Au
Pd
Sum of
Prcious
metals
11660000
─
62
13
79
5
67
19
91
1
4
33
2
42
0
8
6
64
4
73
4
1
6
3
66
8
69
82
9
2
4
3
0
0
3
39
13
2
5
6
25
6
37
24490000
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a The metal price data are from London Metal Exchange (LME) official prices for cash seller and settlement on the 24th
October, 2007.
Toxic Content of E-waste
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E-waste hazards
Average pc of approx. 31.5 kg
Wt. contains
Two million obsolete
Pcs world mean
7.24 kg
Plastic
14/427/000 kg
1.98 kg
Lead
3/962/700 kg
9.92g
Barium
19/845kg
4.94g
Beryllium
9/891kg
2.961g
Cadmium
5/922 Kg
1.981 g
Chromium
3/969kg
0.693g
Mercury
1/386kg
0.4095g
Arsenic
819kg
www.toxicslink.org
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Scope of the problem
Rapidly growing E-waste stream
2002
2005
2009
4.5
3
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H.-Y. Kang, J.M. Schoenung / Resources, Conservation and Recycling 45 (2008) 368–400
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Why recycling E-waste?
1.E-Waste large amount of precious metals
2.E-Waste contain hazardous material
3.E-Waste is a huge secondary resource
above (mine ground) should not wasted
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E-waste recycling content
1.Ban export and disposal as well as incineration
landfilling
2.Advertisement for recycling
3.Collection and transportation
4.Market for reuse
5.Materials recovery facility (MRF)
Resources, Conservation and Recycling 45 (2005) 368–400
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Ban export and disposal
The Basel convention
Disposal = reuse + recycling
The amount of secondhand personal computer exported from Japan in 2005
Hong
Kong
Vietnam
1354963
197815
Thailand Malaysia Chaina Cambodia Korea Others
65323
27264
14440
13011
8598
18015
The amount of seconhand television exported from Japan in 2005
Hong
Kong
Vietnam Cambodia Malaysia Myenmar
Chaina
28356
658293
92779
281124
167723
166010
Thailand Others
35463
15
45259
Advertisement and sorting
Advertisement
Sorting
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Collection and transportation
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MRF for reuse
Market
Materials Recovery Facility
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Electronic Waste in IRAN
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Materials recovery of chemical methods
1. percious metals Recovery
2. hazardous materials Recovery
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Precious metals recovery
1.Pyrometallurgical
2.Hydrometallurgical
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Recovery of precios metals from E- waste by
pyrometallurgical processing
1.Incineration
2.Smelting in a blast furnace
3.Drossing
4.Sintering
5.Reaction in a gas phase at high tempertures
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A summary of typical pyrometallurgical methods for recovery of metals from electronic waste
Techniques
Metals recovered
Main results
Noranda process at canada
Cu, Au,Pt,Pd,Se,Te,Zn
High recovery for Copper
Boliden RÖnnskar
Cu,Ag,Au,Pd,Zn,Pb
High recovery of
Percious metals
Umicore precious metal
refining
Cu,Ag,Pt,Pd,Au
Almost complete recovery
Of Copper
Dunns patent for gold
refining
Au
Days patent for refractory
ceramic percious metals
Pt,Pd
Platinum and palladium
Were recovered with of
80.3% and 94.2%
respectively
Aleksandrovichs patent for
Recovery of gold
Au
Gold were recovered
Recovering special matals
Such as Sb ,Bi, Sn,Se,Te,In
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Advantages pyrometallurgical processing
1.High efficiency recovery precious metals from E-waste
2.Recovery of energy from PC waste gives an example for
using of plastic in E-waste
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Disavantages pyrometallurgical processing
1.Integrated smelters cannot recover aluminum and
iron as metals
2.Ceramic componets and glass in the E-waste
increase the amount of slag from Blast furnaces
3.Precious metals stay for a long time in the
pyrometallurgical processing
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Disavantages pyrometallurgical processing
4.Energy recovery and utilizing of organic constituents as a
reducing agent are only on its beginning
5.Thermal processing of e-waste provides a feasible approach
for recovery of energy from e-waste
if a comprehensive emission control system is installed
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Recovery of precious metals from
E-Waste by hydrometallurgical
processing
The main steps in hydrometallurgical
Separation and purification
Processing consist of a series of acid
of impurities
OrPrecipitation
caustic leaches
of solid material
Solvent extraction
Adsorption
Cementation…..
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Leaching of precious metals
Cyanide leaching
Halide leaching
Thiourea leaching
Thiosulfate leaching
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Halide leaching
Exceptions of flurine and astatine
Gold forms both Au(I) and Au(III) complexes with all
halogens
Low pH
High halogen level
Icreased temperature
High surface area
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Aqua regia
Advantage
2HNO3 + 6HCl
2NO +leaching
4H2O +3Cl2
Halide
The process generally fast
2Au + 11HCl + 3HNO3
2HAuCl4 + 3NOCl + 6H2O
Low reagent consumption
disavantage
Highly corrosive acid
Highly poisonous
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Recovery of precious metale from leachate
Cementation
Zinc cementation
Crowe 1890
2Au(CN)2- +2e
Zn+ 4CNPH 8-11
2Au+4CNZn(CN)4-2 + 2e
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Crushed matter (0.3 mm)
Sulfuric acid leaching of copper
L
Precipitation (NaCl) of Ag
filtration
S
filtration
Chloride leaching of palladium
L
Cu Recovery
S
AgCl
filtration
L
L
Cementation ( Al )
S
Cyanide leaching of gold and silver
filtration
S
Pd,Ag,Au
L
L
filtration
Recycling
S
Activeted Carbon Adsorption
S
Solid waste treatment
Ag,Au,Cu
Recycling
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Comparing with
the pyrometallurgical processing
hydrometallurgical methode is
More exact
More predictable
More easily controlled
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Recovery of hazardious metals
from E-Waste
Cathod Ray Tube
CR T
0.5 – 5 kg pb
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Cathode Ray Tube Recycling
CRT components
1.Glass
Funel glass, panel glass,solder glass,neck
Sio2,Nao,Cao for coloring and
Zno,Bao,Pbo for proctecting from X-Rays
2.Non glass
Plastic,steel,copper,electron gun ,phosphor coating
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Cathode Ray Tube Recycling
1.Glass-to-glass recycling
2.Glass-to-lead recycling
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Glass-to-lead recycling
collection
sorting
Vibratin scrren
Magnetic separation
Eddy current separation
Ferrous metals
Nonferrous metals
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Eddy current
σ: electrical conductivity
ρ : density
σ/ρ : ratio of electrical conductivity to density
Materials
σ (10 -8 / Ώ m )
Ρ (10 3 Kg / m 3 )
σ / ρ (10 3 m 2 / Ώ kg )
Al
0.35
2.7
13.1
Zn
0.17
7.1
2.4
Ag
0.63
10.5
6
Cu
0.59
8.9
6.6
Brass
0.14
8.5
1.7
Pb
0.05
11.3
0.4
H.-Y. Kang, J.M. Schoenung / Resources, Conservation and Recycling 45 (2005) 368–400
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pretreatment
reductant
PbOreverberatory
+ C → Pb + CO
furnace
slage
Soft Pb
99.98%
disposal
landfillsd
H.-Y. Kang, J.M. Schoenung / Resources, Conservation and Recycling 45 (2005) 368–400
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Conclusion
1.Recycling of electronic waste is an important subject
2. E-Waste is a huge secondary resource (maine above ground)
Shouh not wasted
3.The major economic driver for recycling of electronic waste
is from the recovery of precious metals
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References
J.Cui,E.Fotssberg,Mechanical recycling of waste electronic and electric equipment
: a reveiew , j.Hazard .mater.99 (3) (2003) 243-263
EPCEU,:Directive 2002 / 96/EC of the European parliament and of the council of 27
January 2003 on waste electronic and electrical equipment (WEEE) ,off.j.Eur.Union
(2003) 24-38
T. Maruyama, H. Matsushita, Y. Shimada, et al., Proteins and protein-rich biomass as
environmentally friendly adsorbents selective for precious metal ions, Environ. Sci.
Technol. 41 (4) (2007) 1359–1364, Feb 15
A.N. Mabbett, D. Sanyahumbi, P. Yong, et al., Biorecovered precious metals from
industrial wastes: Single-step conversion of a mixed metal liquid waste to a
bioinorganic catalyst with environmental application, Environ. Sci. Technol. 40 (3)
(2006) 1015–1021, Feb 1
J. Shibata, S. Matsumoto, Development of Environmentally Friendly Leaching and
Recovery Process of Gold and Silver from Wasted Electronic Parts, 2007-10-29, 2007
D. Morin, A. Lips, T. Pinches, et al., BioMinE – Integrated project for the development
of biotechnology for metal-bearing materials in Europe, Hydrometallurgy 83 (1–4)
(2006) 69–76.
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