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8/13/2019 4.3 With Notes Final
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TRP Chapter 4.3 1
Chapter 4.3Recycling and waste exchange
8/13/2019 4.3 With Notes Final
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TRP Chapter 4.3 2
RecyclingWhat is recycling? The re-use and remanufacture of
waste materials
What is the purpose of recycling?
To recover useful materials and saveresources
To prevent pollutants reaching the
waste stream
What are the benefits of recycling?
More efficient resource use, lower
energy consumption, reduced
pollution
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TRP Chapter 4.3 3
On-site recyclingBenefits:
close to the point of generation
less contamination
lower cost raw materials
reduced waste disposal costs
Costs:
capital investment in equipment
staff training
maintenance and repair staff time
residue disposal
quality control
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TRP Chapter 4.3 4
Off-site recyclingFactors influencing off-site recycling:
if on-site recycling is not appropriate
if on-site recycling is not cost-effective
availability and location of recycling facilities
availability of advanced technology
economies of scale
Need:storage for materials awaiting collection
transport to off-site facility
Materials commonly recycled off-site include:oils, solvents, electroplating sludges, lead-acid batteries
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TRP Chapter 4.3 5
Secondary raw materials
Use of secondary raw materials is common insome sectors egmetals, paper, oil
Economics of process may depend on
recycling of by-products
Large international trade in many such wastes
Technology for processing requires large
investment, high volumes
May generate new problematic residue stream
May provide opportunities for illegal practices
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TRP Chapter 4.3 6
Recycling technologiesRecycling Technology Waste Type
1 2 3 4 5 6 7 8 9
Activated-carbon Absorption
Distillation
Steam Distillation
Electrolytic RecoveryIon Exchange
Hydrometallurgical Concentration
Membrane Separation
Evaporation
Freeze-Crystallisation
1 - Corrosive wastes
2 - Cyanide containing wastes
3 - Halogenated solvents
4 - Non-halogenated solvents
5 - Other organic wastes
6 - Oil-containing wastes
7 - Metal containing wastes
8 - Organic containing wastes
9 - Reactive wastes
Pyrometallurgy
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TRP Chapter 4.3 7
Solvent recovery 1
Simple solvent recovery plant, SE Asia 1990
Source: David C Wilson
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TRP Chapter 4.3 8
Solvent recovery 2
Source: David C Wilson 1990
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TRP Chapter 4.3 9
Case study: Battery recycling
leaching
residue
washing
electrowinning
melting and
casting
purification
Bi, Cu, As, Sb ...
99.99% Pb
ingots
Inert
residues
paste
PLACID Process
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TRP Chapter 4.3 10
Case study: Advantages of
process No liquid effluent discharges
Leaching residue is inert gypsum Dusts and drosses are recycled
Leaded slags and soils can be treated
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TRP Chapter 4.3 11
Waste exchange Puts generators in contact with potential
users
Example of off-site recycling
Some free, some charge fees
List wastes available and wanted
Some local, some regional, a few
national
Number increasing thanks to Internet
Printed catalogue or computerised on-
line systems
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TRP Chapter 4.3 12
Wasteexchange
Types of waste exchangeInformation clearinghouse or material broker
Waste
generator User
Information on
wastes available
Information on
wastes wantedInformation on
wastes wanted
Information on
wastes available
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TRP Chapter 4.3 13
Which wastes? Wastes arising in small quantities
Wastes needing specialised recycling
High value materials not usable by
generator Low value materials
Off-specification products
Contaminated material
Surplus and outdated materials
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TRP Chapter 4.3 14
Waste listingsOften divided into Requests and Offers egRequests
Ethanol, sodium hydroxide
Electronic scrap
Fertilisers
Metal containing wastes
Organic materials
Sludges
Offers
Copper sulphate
Fluorspar
Hydrochloric acid
Magnesium hydroxide
Filter cakes
Sodium sulphate
May give detailed description egPhenol formaldehyde resin from vat coating of
fibreglass. Solution contains 54% phenolic resin in 23%
ethanol with 1% formaldehyde by net weight. 5 drums
available.
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TRP Chapter 4.3 15
Measuring successvolumes recycled
raw materials saved
costs reduced
awareness raised
Example: US Dept of Defense Defense
Reutilisation MarketingOrganisation
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TRP Chapter 4.3 16
Influences on expansion of waste
exchanges
Internet
Integration of exchanges
Government support and funding
Research into opportunities for particular wastes
Limited liability for users
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TRP Chapter 4.3 17
Chapter 4.3 Summary Recycling of hazardous waste has a number of
benefits
It may take place on-site or off-site, depending
on the waste and the technology
It generates residues
Many processes use secondary raw materials
as feedstock
Waste exchange helps promote re-use and
recycling, maximise diversion from disposal