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TRP Chapter 4.3 1

Chapter 4.3Recycling and waste exchange

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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