Recycling and Re-Use in Steel

8/3/2019 Recycling and Re-Use in Steel

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Corus Construction Centre

Environmental design in steel

Recycling and re-use in steel


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Of the 700 million tonnes/year of global steelproduction, almost half is recycled from scrap.

Steelthe worldsmost recycled

material

Contents

1 The steel product cycle

2 The role of steel recycling

4 Recycling and re-use:

Sustainability in practice

7 Steel recycling infrastructure

8 Reducing impacts

Environmental benefits of steel/

references

1. Scrap

2. Smelting

3. Manufacture

4. Use

5. Re-use


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The steel product cycle

1Recycling and re-use in steel

3. ManufactureEnough steel is recycledevery day to make theequivalent of 150 Eiffel

Towers. However, that is notsufficient to m eet demandand so over 50% of steel

must be made fromprimary ore.

4. UseSteel may be consideredas a renewable resource.It is not sold but leased,to be returned at the end

of its life for recycling.

5. Re-useSteel buildings can be

readily designed tofacilitate disassemblyand re-use at the endof their useful lives.

1. ScrapSteel is the worlds mostrecycled material and is

serviced by a wellestablished infrastructure

of scrap p rocessors whichhas been in existence

for over 100 years.

2. SmeltingCoatings on steel productsdo not represent a barrierto recycling. They can be

recycled in turn, burned offor recaptured.


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The role of steel recycling

2 Recycling and re-use in steel

Energy saving

The amount of steel recycled globally is equivalent to18 Forth Rail Bridges or 1.2 million cars every day. Ina typical year in the UK, the steel industry, throughrecycling saves enough energy to provide all theelectricity required for several million households.


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The role of steel recycling


Recyclability of steel

Steel is unique among major

construction materials in that it

always contains recycled content; it

is completely recyclable at the end

of its product life and may berecycled an unlimited number of

times without loss of quality.

Worldwide, over 90% of steel

production uses one of two types of

process, elect ric arc furnaces (EAF)

or basic oxygen furnaces (BOF).

The basic oxygen furnace uses a

minimum of 20% scrap; this

process accounts for approximately

a third of all scrap use. The

remainder is used in electric arc

furnaces which melt virtually 100%

scrap.

Steel products are very durable. The

long life of modern cars, appliances

and steel construction products,

together with global economic

expansion, creates demand that

cannot be fully met by availablescrap supplies. This makes it

necessary to use steel from primary

ore to supplement the production of

new steel.

Steel does not rely on specification

of recycled scrap content to drive

demand. An extensive worldwide

infrastructure for recycling scrap

has been in operation for over 100

years. The recycling ratio, defined

as the ratio between the actual

quantity of scrap salvaged and

recycled and the total quantity of

scrap arising, is around 80% on a

global basis. The use of recycled

steel has already almost certainly

reached its maximum practical

capacity (REF 1).

After its useful product life steel can

be recycled regardless of its origin.

All methods of production are

complementary parts of the total

interlocking infrastructure of

steelmaking, product manufacture,

scrap generation and recycling.

Raw materials Materialspreparation

Ironmaking Steelmaking

Integrated Steelmaking

Coal

Limestone

Iron ore

Coke ovens

Sinter plant

Blast furnace

Electric Arc Steelmaking

Electric arcfurnace (EAF)

Scrap metal

Basic oxygenfurnace (BOF)

Figure 1

Steel making - whether it is via the basic

oxygen or the electric arc furnace method,steel always contains recycled material.


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Recycling and re-use: sustainability in practice


Crossing

barriers

Previous uses of steel do not

generally present a barrier to post-

recycling application.


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Recycling and re-use: sustainability in practice


Re-use of steel

A characteristic of steel buildings is

that they can readily be designed to

facilitate disassembly or

deconstruction at the end of t heir

useful lives.

This has many environmental

advantages; it can mean that steel

components recovered in this way

can be re-used in future buildings

without the requirement for

recycling. This reduces the energy,

CO2 and other environmental

burdens generally associated with

the manufacture of all construction

materials. An additional advantage

of designing for disassembly and

re-use is the reduction in

neighbourhood disruption and

pollution during the d emolition

process. The likelihood of waste

going to landfill is also reduced.

An example of a steel framed

building which has been

reassembled and re-used can be

found in Germany where a Munichcar park was moved in entirety

across the city and reassembled

with the addition only of some new

foundations, baseplates and access

ramps.

In the UK a demonstration that the

disassembly of steel frames for

future re-use is not a modernconcept is provided by Hangar No.

2 at Cardington. This building,

containing 3720 tonnes of steel,

was originally erected in Norfolk. It

was later moved, enlarged and

rebuilt on its present site. It is now

home to the largest and tallest

single enclosed research and test

facility in Europe, BRE Cardington.

Steel structures can also be reused

without demolition. The

refurbishment of Winterton House in

London was carried out on the

original frame with only minor

changes to the steelwork and

connections to accommodate the

modified loadings. See following

page.

Galvanised and painted steelCoatings on steel products do not

represent a barrier to recycling.

Galvanised and painted steel is

recycled; the fillers in the paint are

organic in nature and are burned

off; the pigments, which are

resistant to high temperatures are

removed with the waste products.

Steel, the natural sustainable

choice

The high recovery rates for steel

from scrap mean that very little is

wasted. In practice this means that

steel is not bought and sold but is

leased for the duration of the

current application to be returned

for re-use and recycling time and

time again.

This steel framed car park in Munich was

dismantled and completely reassembled

on the other side of the city.

Building Research Establishment,

Cardington Research and Test Facility.

Recycling and re-use: sustainability in practiceThe recycling process progressively reduces theenvironmental burdens associated with each

successive application, providing a robust foundationfor sustainable development.


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Recycling and re-use: Sustainability in practice



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Steel recycling infrastructure


Winterton House before and after

refurbishment. See previous page.

Recyclinginfrastructure

Sources of scrap steel

The steel industry has been

recycling steel through scrap

processors for more than 100 years.

The well established infrastructure

prepares all types of scrap for

shipment to steel mills and

foundries for resmelting into new

steel. Each year, millions of tone of

pre- and post-consumer steel scrap

are recycled.

The main sources of steel scrap are

unwanted or discarded cars,

household appliances, steel cans

and old buildings and structures.

Recycling yield

Steel is degraded very little, if at all,

in the recycling process so it can be

recycled a very large number of

times. The only limitation is

enforced by the recycling yield, or

the percentage which survives from

one recycling stage to the next. For

example, if a building containing

100 tonnes of constructional steel is

dismantled to recover 99 tonnes of

scrap which is subsequently

transported and re-smelted to

produce 95 tonnes of useful steel

product, the recycling yield is 95

per cent.

The recycling yield of any material

is determined by several factors.

1 The effectiveness of the recovery

process form previous uses.

2 The effectiveness of the

collection and sorting system.

The steel scrap industry is well

established locally, nationally

and internationally and sorting

steel scrap from other materials

is uniquely facilitated by its

magnetic properties.

3 The technical difficult ies of

reprocessing. A product can be

recovered and collected easily,

but its recycling yield will be lowif reprocessing is wasteful.


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Reducing impacts


The effects of recycling in life

cycle assessment (LCA)

calculations

It is universally recognised that an

assessment of the environmental

impacts of a material needs to be

considered over its whole life cycle,

or so called cradle to grave,

including extraction, manufacture,

transport, construction,

refurbishment, re-use, recycling and

disposal of waste (REF 2).

In order to account properly for the

effects of re-cycling in LCA

calculations it is necessary to

identify, among other things, the

recycling yield of a material and to

have available simple calculation

methods to estimate how the

environmental burdens are reduced

at each recycling stage.

Reduction of environmental

burdens

The Steel Construction Institute has

developed a simple formula which

relate the environmental burden at

each stage of recycling to those

associated with the primary and

previous re-cycling processes, and

to the re-cycling yield (REF 3).

This formula, described in Figure 2,

illustrates how the burden at each

stage is progressively reduced but

reaches a near constant value after

several recycling iterations.

In principle the same picture applies

to a wide spectrum of

environmental burdens such as CO2,

SOx, NOx and other emissions and

discharges.

Reducingimpacts

GJ/Tonne

Number of cycles

17

19

21

23

25

1510 12 14 16 18 200 2 4 6 8

Steel component recovery and re-used reduces theenergy, CO2 and other environmental burdens of the

steelmaking process by virtually one half on the firstre-use.

Figure 2

Embodied energy


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Environmental benefits of steel

100% recyclable

Uses minimum volume of material

Clean, dust free construction

Minimum site waste

Good end of life options

- dismantle and re-use

- demolish and recycle

- remove steel foundations

Offsite fabrication in controlled

environment

Adaptable and flexible to suit

changing requirements.

References

1 Worldwide LCI Database from

steel industry products. Technical

Report 1 April 1998. Available

from the International Iron and

Steel Institute, Brussels.

2 Life Cycle Assessment in Steel

Construction.

Available from


PO Box 1, Brigg Road

Scunthorpe DN16 1BP.

3 Amato, A. A comparative

environmental appraisal of

alternative framing systems foroffices. Thesis submitted in

partial fulfilment of the

requirements of Oxford Brookes

University for the degree of

Doctor of Philosophy, July 1996.

Further reading and guidance

1 Guide to thermal capacit y in

buildings.

Available from


PO Box 1, Brigg Road

Scunthorpe DN16 1BP.

2 Eaton, K and Amato, A (1998)

A comparative environmental life

cycle assessment of office

buildings. Available from the

Steel Construction Institute,

Silwood Park, Ascot, SL5 7QN.

Tel (01344) 623345 Fax: (01344)622944. Publication reference

P182.


The Corus Construction Centre is

the name of the new technical

advisory service at Corus providing

full product and applications

support for carbon steel, stainless

steel and aluminium in construction.

From buildings to bridges, towers to

tunnels, foundations to flotation

structures, whatever your

requirement, we have the

knowledge and experience to help

realise your creative concepts.

Staffed by a multi-disciplinary team

of construction professionals, theCorus Construction Centre is there

to provide designers with guidance

on the selection, usage, integration

and recycling of ferrous and non-

ferrous construction metals.

By using this service, the Corus

Construction Centre can help you to

speed up the design process,

facilitate innovation and encourage

more efficient solutions.

Contact the Corus Construction

Centre on:

Technical Hotline

+44 (0)1724 405060

Facsimile

+44 (0)1724 404224

Email

corusconstruct [email protected]

Literature Line+44 (0) 1724 404400

Website

www.corusconstruction.com


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PO Box 1

Scunthorpe

North Lincolnshire

DN16 1BPUnited Kingdom

T +44 (0) 1724 405060

F +44 (0) 1724 404224

English language version JD:1000:UK:11/2001

www.corusgroup.com

Care has been taken to ensure that the

contents of this publication are accurate, butCorus UK Limited and its subsidiary

companies do not accept responsibility for

errors or for information which is found to be

misleading. Suggestions for or descriptions of

the end use or application of products or

methods of working are for information only

and Corus UK Limited and its subsidiaries

accept no liability in respect thereof. Before

using products supplied or manufactured by

Corus UK Limited and its subsidiaries the

customer should satisfy himself of their

suitability.

Copyright 2001

Corus

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Recycling and Re-Use in Steel

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