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                      TECHNICAL PAPER # 10
                    SCRAP METAL RECYCLING
                           Jon Vogler
                       Technical Reviewer
                           David Reins
                          Published By
 1600 Wilson Boulevard, Suite 500, Arlington, Virginia 22209 USA
         Telephone: (703) 276-1800, Fax: (703) 243-1865
              Telex: 440192 VITAUI, Cable: VITAINC
        Internet, Bitnet vita@gmuvax
                 Understanding Scrap Metal Recycling
                        ISBN: 0-86619-210-7
            [C]1984, Volunteers in Technical Assistance
This paper is one of a series publisher by Volunteers in Technical
Assistance to provide an introduction to specific state-of-the-art
technologies of interest to people in developing countries.
The papers are intended to be used as guidelines to help
people choose technologies that are suitable to their situations.
They are not intended to provide construction or implementation
details. People are urged to contact VITA or a similar organization
for further information and technical assistance if they
find that a particular technology seems to meet their needs.
The papers in the series were written, reviewed, and illustrated
almost entirely by VITA Volunteer technical experts on a purely
voluntary basis. Some 500 volunteers were involved in the production
of the first 100 titles issued, contributing approximately
5,000 hours of their time. VITA staff included Leslie Gottschalk
and Maria Giannuzzi as editors, Julie Berman handling typesetting
and layout, and Margaret Crouch as project manager.
VITA Volunteer Jon Vogler, the author of this paper, is widely
published in the field of recycling. His book Work From Waste,
published by the Intermediate Technology Development Group, Ltd.,
London, England, describes how to recycle paper, plastics, textiles,
rubber, minerals, chemicals, oil, human and household
wastes, as well as metals. Mr. Vogler, an engineer, worked in
Oxfam's "Wastesaver" program in developing countries. He has done
much research in the field of recycling waste materials. The VITA
Volunteer reviewer of this paper, David Reins, has been an industrial
arts teacher for several years. He has also been a mechanic
and has worked with precision machines and sheet metal.
VITA is a private, nonprofit organization that supports people
working on technical problems in developing countries. VITA offers
information and assistance aimed at helping individuals and
groups to select and implement technologies appropriate to their
situations. VITA maintains an international Inquiry Service, a
specialized documentation center, and a computerized roster of
volunteer technical consultants; manages long-term field projects;
and publishes a variety of technical manuals and papers.
                  by VITA Volunteer Jon Vogler
The recycling of metals is probably as old as other forms of
metal working, which the book of Genesis gives as the occupation
of Tubal Cain, eight generations after Adam, who "made all kinds
of tools out of bronze and iron." Perhaps the earliest reference
is in Isaiah: "[they] shall beat their swords into plough shares
and their spears into pruning hooks." This is probably because
the recycling of metals uses the same processes as the production
of metal from ore. So important were these processes, that
civilizations were labeled by them. The "bronze age" covers man's
first production of tools (other than primitive stone axes) and
the 'iron age' of tools that would cut without losing their edge.
Gold and silver money likewise has been repeatedly recycled: by
melting down and casting or stamping new coins. Much of the
history of the modern world has been caused by the recyclability
of metals: the Spanish Conquest of Latin America in the fifteenth
century was carried out because the gold and silver that
had been produced from ore by the Mayas and Incas could be melted
down and converted into jewelry and bullion for the King of
Little attention was paid to recycling during the industrial
revolution. Bessemer's invention of the blast furnace (published
1856) made it possible to produce new steel in huge volume:
only in times of war when the importation of metal ores has been
prevented, has recycling flourished. The campaign to collect
aluminum saucepans to make Spitfire airplanes was enormously
popular in Britain in 1940. However, metal recycling is still
politically significant: it was the presence of scrap-metal
collectors on a remote South Atlantic Island that triggered the
war over the Falklands/Malvinas Islands.
Metal scrap, although unfamiliar to most people, is one of the
world's larger industries with regard to the number of companies
and people employed, weight of material handled and value of
equipment used. It offers exceptionally good opportunities, for
creating new businesses in developing countries, whose production
or generation of scrap will increase rapidly with industrial
and urban growth. Governments like it because it saves foreign
exchange, conserves energy (recycling metals uses far less energy
than primary metal production from ores), and creates substantial
It is convenient to split them into three categories: ferrous,
non-ferrous, and precious. Ferrous metals are those that contain
iron and the main difference is that these are cheap and are
recycled in huge quantities:   hundreds, thousands, or even tens
of thousands of metric tons.   Non-ferrous are those with no
iron: they include copper, aluminum, lead, and so on and quantities
are much smaller: tens of tons or even a few kilograms
may be worth large sums of money. Precious metals include gold,
silver, platinum, etc., and just a few grams may be very valuable.
    Table 1. Typical Scrap Metal Prices: Britain 1984
                                                     Price per Ton
 Metal                       Grade                         (US$)
 Ferrous                     HMS1                          61.00
                            HMS2                          49.00
                            Light                        31.00
                            New or detinned bales        73.00
                            Cast iron                    61.00
 Copper                      New scrap                    976.00
                            Old scrap                   854.00
                            Brass                       732.00
                            Car radiators               671.00
                            Bronze                      1098.00
 Aluminum                    New cuttings                 915.00
                            Old                         732.00
 Lead                        Old scrap                    305.00
                            Car battery plates            85.00
                            Car batteries                61.00
Zinc                        Old scrap                   427.00
                            New cuttings                488.00
Because of these differences, the sources of scrap, the markets
into which they can be sold, and the methods, equipment, and
skills needed for recycling also differ greatly. In the main body
of this paper the categories will be discussed separately, but
the reader should note that there is much overlapping: for example,
certain furnace types may be used for all categories of
scrap and some types of scrap, such as tinplate which contains
steel (ferrous) and tin (non-ferrous), bridge two categories. In
the latter part of the paper, general principles of metals recycling
will be discussed and these are applicable to all categories.
Much metals recycling feeds recovered material (sometimes called
secondary) back into the same industries that produced it in the
first place (primary industries). To establish a business that
will recycle metals profitably it is therefore essential to be
familiar with the primary industries, especially with the giant
steel industry, so the sections on each metal will describe these
in outline.
The Production of Iron
Iron is a natural element, usually found as an "oxide" of iron
mixed with other minerals and called iron ore. This is heated in
a blast furnace to produce metallic iron called pig iron (so
called because the molds in which it used to be cast were arranged
around a central channel like piglets suckling a sow!)
Pig iron has two uses. It can be melted in a foundry where it is
cast into molds to produce solid, heavy objects and objects with
complicated shapes such as are listed below in the section, "The
Forge and the Foundry." It can also be made into steel.
The Production of Steel
Pig iron contains another material: carbon (familiar as coal or
charcoal). Steel is iron with little carbon; steel making is
simply the removal of the carbon by burning. This makes the
steel stronger, more flexible, and easier to cut than iron.
There are many different processes for making; steel from pig
iron. All produce molten steel, which may then be cast to produce
an end-product. Steel castings are not as common as iron but are
stronger. Steel may be cast into ingots for forging, the process
of hammering hot steel, to make items of extreme toughness; and
strength. It may also be cast into slabs blooms, or billets for
rolling. (Slabs, blooms, and billets are chunks of steel ready
for further shaping.) Rolling is the most common process for
shaping steel. The billet is heated until it glows yellow, then
passed forwards and backwards between powerful steel rollers of
the correct size and shape to produce the cross-section that is
required. Steel sections in turn may be cut, cold-rolled,
forged, welded, electroplated, or treated in many other ways to
form the huge variety of steel components in use in the world
Ferrous scrap can be fed back into the iron and steel manufacturing
processes already described at any of a number of stages:
Foundry Scrap
Scrap iron or steel may be melted in a cupola or rotary
furnace(see below for descriptions) to make iron or steel castings. It
is usually mixed with pig iron.
Steel Mill Scrap
Scrap steel, but not cast iron, may be melted in an electric-arc
steel-making furnace and cast as billets for rolling.
Rerolling Scrap
Large pieces of scrap steel may be cut to regular shapes and hot-rolled
into new sections of a smaller size. Rerolling is practiced
widely in parts of Asia, but less elsewhere. Thick scrap
is flame cut into parallel-sided slabs that are heated in an oil-fired
furnace (but not melted, so the furnace is simpler and
cheaper than that used in a steel mill and less energy is used).
It is then rolled in a four or five stand mill (a stand is one
pair of rollers). Capital cost of the plant may be as little as
US $180,000 (or even less for a used plant).
Rerolling is very suitable for thick plates from shipbreaking
(cutting up of old ships), an industry being adopted by many
Third World countries short of heavy scrap. It requires a very
high degree of technical and manual skill and is not recommended
as an activity to anyone without previous rolling mill experience.
Re-using Scrap
Steel may be used as a raw material and cut, formed, forged, or
treated in any other way to fabricate new objects. Rerolling and
re-use yield far more value from a given weight of scrap) and
should be tried wherever possible. Two waste materials justify
special mention because they are so commonly used in this way:
oil drums and reinforcing steel.
Oil Drums.  The standard 45-gallon (200-liter) oil drum can be
used as a container for liquids or soilds; as a waste bin; converted
into a small (but short lived) furnace; mounted on a cart
or truck or cut open to make an animal feeding trough. It is
even more widely used as a source of raw material. When flattened
out, an oil drum makes a rectangular sheet of steel 180 x 90 cm,
plus two circular pieces 57 cm in diameter.
Reinforcing Steel.  Concrete is often strengthened with steel reinforcing
bars. These are made in standard lengths and cut to
size on the construction site. The off-cuts are a useful material
that can be cut with an ordinary hacksaw, bent across the
knee or heated in a simple charcoal forge to flatten or shape an
In Kenya, a number of workers have developed a whole industry
using reinforcing bars and similar materials. These enterprising
men have made hand-operated punches, folders, and other metalworking
machinery, all from scrap metal. From these they manufacture
such products as heavy-duty bicycle carriers, stands
and foreguards (strengthener between forks and handlebars), small
agricultural tools, and metal working tools.
The forge and the foundry are two processes that can use ferrous
scrap to produce finished goods for re-sale.   They therefore
provide excellent markets for the metal scrap reclaimer. However,
many Third World towns do not have a local foundry or forge
and the nearest is often many miles away. Not only is there no
market for scrap metal, but all types of iron and steel objects
have to be brought in and are very expensive.   This situation may
justify setting up a small forge or foundry locally, which will
create employment, provide a market for scrap metal (and employment
for scrap collectors and sorters); and provide cheaper iron
and steel goods with less delay and difficulty.
The Forge
In order to flatten or shape a piece of solid steel it must be
heated to red and then yellow heat, at which point it becomes
softer and more workable. The furnace in which pieces of steel
may be heated is called a forge and the word is also used to
describe the complete workshop in which forging is done. For
working with reinforcing steel and similar sizes of scrap, a
forge may be very small with simple requirements, namely:
     *    A bed of coal, coke, or charcoal
     *    A source of draft (wind) through the bed
     *    An anvil
     *    Tools for handling and hammering the hot workpiece.
Products That Can be Made by Forging
Agricultural tools              such as hoes, rakes, mattocks,
                               axes, plow blades
Axles                           for carts, trolleys, trailers
Carpenter's tools               such as hammers, pincers, screwdrivers,
                               chisels, adzes, drill bits
Mason's tools                  such as stone chisels, trowels,
                               hammers, crowbars
Garage equipment                such as ramps, brackets, tow hooks
Fittings for boats              such as rowlocks and cleats
Machine parts                   of all sorts, especially for the
                               many items described in this paper
                               such as baling presses, shears,
                               furnaces, etc.
The Small Iron Foundry
Foundry work requires long training. The quality of locally produced
goods may be low, until skill and experience are obtained.
Mass produced goods, even those imported, may still turn
out cheaper despite the cost of transport. Foundry management
needs organizing ability, practical skill, and determination.
Equipment Needed for a Small Foundry
         *     Storage space for scrap metal and means of carrying and
         *     Furnace for melting the metal
         *     Wooden patterns and a workshop for making them
         *     Molding and sand preparation equipment
         *     Casting equipment
         *     Finishing equipment
         *     Safety equipment
Products That Can be Made In a Small Foundry
Table 2 is taken from a report on the foundry industry undertaken
by a developing country in the South American Andes and may be
regarded as typical. No other process can produce complicated
shapes so readily.
    Table 2. Products That Can Be Made In a Small Foundry
spare parts for machinery      sand mixers         shoe lasts
manhole and drain covers       motor casings       coffee machinery
weigh scales                   well covers          bench ends
car and truck parts            burners             wheels
weights and counterweights     shelving brackets   bed brackets
bearings                       stoves and heaters   shears
molding presses                textile machinery   grinders
Some of the major types of furnaces are described below and compared
in Table 3.
Electric Arc Furnace
The electric arc furnaces used in steel mills are huge, capable
of melting seven tons of metal per day upwards, and very expensive.
However, it is possible to construct a tiny model for
foundry work. It comprises a cylindrical pot, less than a meter
high, of alumina brick and magnesite. The brickwork is held
within a steel hoop mounted on a shaft that rotates in
simple vee-blocks. The lid, of fireclay encompassed by a steel band, is
penetrated by two graphite electrodes, which in turn are held in
copper clamps mounted on a tilting and lifting mechanism. A pair
of parallel- connected, direct-current arc welding generators
(such as those manufactured by Lincoln Electric Company) provide
current (of up to 1000 amps each at 40 volts) by thick flexible
cooper cables to the electroded clamps. The generators are run
off the three-phase main electric supply.
The furnace is charged with small pieces of scrap and the lid
lowered. The arc strikes from one electrode to the scrap and
back to the other electrode. As the charge melts, the electrodes
are lowered by hand wheels. It takes about one hour to melt a
charge. The electrodes are used up in the course of operations
and have to be renewed, so the unit is not cheap to run compared
with other types of small furnaces. On the other hand, it is
flexible, handy to use for small batch work, and of comparatively
low capital cost.
The Cupola
A cupola is not unlike a small blast-furnace: a vertical cylinder
of steel plates, lined with bricks or other heat-resistant material
to protect the steel from the intense heat generated. It has
a vertical, cyclindrical steel shell, with air holes above the
bottom doors.
The smallest practical size can produce just over one ton of
iron per hour from a charge of 140 kilos of iron and 20 kilos of
coke in each layer. One kilo of lime or sea-shells is added to
flux the iron (prevent oxidation and allow slag to drain away
more easily through the slag hole at the back, which is opened
from time to time). It is cheap to build and operate but too
laborious to use for small quantitites of material. Once at full
stretch it can melt about four and one-half tons of metal in half
a working day. So, it is only operated about once a fortnight.
Casting molds are stockpiled in preparation and the cupola kept
on heat until every mold has been filled.
Rotary Oil Fired Furnace
This consists of a steel cylinder with conical ends and the point
of the cone cut off to leave a hole about half the diameter of
the cylinder.  The cylinder is mounted inside circular turning
wheels that fun on slow, electrically driven rollers.   The
turning agitates the scrap and speeds melting.   Scrap and pig
iron are charged in through one circular end hole.   At the other
end is the burner, which uses gas or bunker oil blown through a
nozzle with air from a power fan.   Pouring takes place through a
spout in the middle of the cylinder wall.   Slag is removed
through a spout in one end. A separate cylinder is used for each
different type of metal to prevent contamination.
The Crucible Furnace
The crucible furnace is used for small-scale operations, more
often with non-ferrous metals but also for cast iron and steel.
It differs from the furnaces just described in that the fuel and
the metal are kept totally separate, giving much better control
over purity and composition.   This is achieved by holding the
metal in a fire clay crucible that is seated inside the bucket-shaped
furnace.  Although the furnace can be coke-fired, oil or
gas are more convenient as they heat more quickly than coke, are
more widely available, and are simpler to use in a tilting furnace.
The furnace and its lid are lined with firebrick and mounted on
strong bearings at the center of gravity.   The oil burner flame
enters through a hole in the bottom while the burner pump is
behind the screen to prevent damage from slag or hot metal during
work.   The crucible is suspended in the center so that it is
surrounded on all sides by a jacket of heated air. Tilting is by
hand wheel action through a reduction gear box. For higher temperature
work, crucibles are made from graphite mixed with the
fire clay.  They are fragile when cold but strong when heated.
Each crucible should be used only for one type of metal.
Induction Furnace
This is similar to the crucible furnace except that the crucible
is set permanently in the furnace, surrounded by a water-cooled
electric coil. A high frequency (1000 cycles per second) alternating
current is applied by a special generator.   The coil
creates a magnetic field that induces electric currents in the
charge to generate heat and melt the scrap.   A large unit can
contain up to four tons of scrap and takes a little over an hour
to heat, but much smaller units are commonly used, even down to
the laboratory models holding only a few pounds.   However, they
are expensive for their size.
Induction furnaces are very clean and there is no possiblity of
chemical changes due to contact with fuel or the high temperatures
of the electric arc furnace, so they are very suitable for
non-ferrous metal and alloy steels.   Another advantage is that
cast iron can be made from steel scrap without the need for
imported pig-iron.  The process is called recarburizing and requires
graphite charcoal and ferro-silicon additions.
A good combination for starting a small foundry would be a cupola
for cheap, large volume casting, plus a small electric arc or
induction furnace for small quantity work required quickly.
            Table 3.  Furnaces for Melting Ferrous Scrap
Type of                         Charge                                  Capital
Furnace         Fuel          Material        Product        Size        Cost
Cupola          Coke or       Solid pig     Cast iron        Medium      Low
                 hard            iron
Rotary           Oil          Solid pig      Cast iron        Medium     Medium
furnace                           iron
Crucible        Gas, oil,        None        Steel and        Small       Low
                or coke                     cast iron
Electric        Electricity      None        Steel and        Small     Medium
arc                                          cast iron                  or high
Induction       Electricity      None        Steel and        Small      Medium
furnace                                      cast iron                   or high
Air or          Pulverized       Molten or   Cast iron       Medium      Medium
reverberatory   coal or oil       solid pig                 or large    or high
Scrap is recovered from a variety of sources. Scrap handling
covers the processes of collection, grading, and preparation.
Sources of Steel Scrap
Construction sites.  Off-cuts of reinforcing steel, rods and
mesh, wire and nails.
Demolition sites.  Poles, girders, joists, steel doors and windows,
drain covers, pipes, railings, grills, etc.
Engineering workshops.  Off-cuts, swarf (turnings and chips from
lathes, drills, etc. , discarded motor parts, scrap cars.
Factories, mines, quarries, drilling sites, farms, technical
colleges, etc.  Discarded machinery, construction steel, partitioning,
drums and containers, pipes, tanks, carts, motors, in
Streets, parks, and waste land.   Discarded railings, manhole covers,
pipes, etc.
Households.  Domestic appliances (cookers, refrigerators, etc.),
tin cans, broken bicycles, perambulators (prams), toys, tools,
furniture, etc.
Refuse dumps.  Any of the above.
Scrap Collection
This involves three main activities:
Negotiation.  To buy scrap, demolish machinery, clear scrap lying
in public places.
Handling.  By laborer or by crane, often with equipment for metal
cutting, unbolting, and loading onto vehicles.
Transport.  By cart, truck, railway, wagon, etc.
The use of skips can reduce costs significantly. A skip is a
steel container in which the supplier stores scrap for the dealer
to collect with a specially adapted skip loader truck.
The equipment for collecting scrap metal includes the following:
     *    a strong cart or vehicle is essential
     *    leather gloves
     *    boots with steel-reinforced toe-caps
     *    block and tackle
     *    a hacksaw
     *    bolt croppers
     *    axe
Grading of Scrap
The following list of ferrous scrap grades should serve anyone
selling scrap in a Third World country that has one or more steel
rolling mills, usually with electric arc furnaces, and a number
of small or large iron foundries, plus workshops of different
kinds.  In countries without such industry, different grading,
possibly aimed at export, will be needed. The grades include:
     *    cast iron
     *    heavy melting scrap, also known as HMS or "No. 1"
     *    medium scrap (or "No. 2")
     *    light scrap (or "No. 2 bundles" or "No. 3")
These may be in the form of:
     *    swarf
     *    re-rollable pieces (only if re-rolling mills exist)
     *    re-usable pieces
Cast Iron.  Cast iron can be identified by its dull grey color,
comparative weakness (it can often be broken by a hammer blow),
and complicated cast shapes, sometimes with numbers or words cast
proud of (higher than) the surface.   It is one of the most valuable,
highly priced forms of scrap and can be sold to a local
iron foundry.
Heavy Melting Scrap.  Whenever possible, steel scrap should be
sold directly to a steel mill. In Third World countries these are
mostly mini mills, using electric arc furnaces, which operate as
follows: a first charge of scrap is melted, the glowing electrodes
withdrawn, the top cover swivelled away and a second load
of scrap discharged into the furnace from the charge basket.
molten metal that determines the economics of furnace operation.
Valuable time and energy are saved by reducing the number of
times the furnace has to recharge.   For this reason, steelmakers
will pay far higher prices for smallish pieces of solid, heavy
scrap more than 6mm thick which will form a heavy, dense charge.
Scrap that fills this requirement is HMS and fetches an excellent
price; bales of new or detinned sheet steel are even better (see
Obviously, large furnaces can accept much longer pieces than can
mini mills.  In Britain, the maximum length of HMS is 1.5m.
Elsewhere, mini mill furnace diameters are often not more than 2m
and charge baskets 1.5m, in which case material of about two-thirds
of a meter in length is preferable.
Medium Scrap.  This includes material which is thinner than 6mm
but is reasonably free from rust, dirt, and any metals that cause
difficulties in steel-making, especially tin and copper. Medium
scrap may be sold to a foundry or steel mill.   The pieces should
be cut into lengths that will make a dense furnace charge easy
to obtain.  It is not economical to cut No. 2 scrap with expensive
gases; an alligator shear is essential.
Light Scrap (No. 2 bundles or No. 3).   This is the lowest acceptable
quality and fetches the lowest price.   It contains sheet
material that is not able to be included in No. 2 because:
     *      it is too thin
     *      it is too rusty
     *      it is coated or contaminated with tin, and
     *      it is heavily coated with paint or oil.
Scrap Preparation Processes
Three mechanical processes are commonly used to prepare the
scrap-baling, shearing, and shredding.   Chemical processes are
also used in certain circumstances.
Baling.  The material is compressed in a powerful mechanical or
hydraulic press, to produce dense, cubical blocks called bales.
Light scrap such as large, rusty sheets of galvanized (zinc
coated) steel are the worst forms of furnace feed, but even they
can be made more acceptable (and that means a better price, by
baling them. The advantages of baling are:
     *     more weight can be loaded on a truck so transport cost
          is cut
     *     more material can be stored in a given space so a
          better price can be negotiated for the larger quantity
     *     the buyer finds storage is easier so will pay a little
     *     handling and loading are easier, quicker and cheaper
     *     a denser furnace charge is obtained.
Shearing.  The material is chopped to length by a powerful blade.
The cheapest machine is an alligator shear that will cut HMS of
20cm thickness. Larger shears are even more powerful.
Shredding.  Used on thin steel that may contain other materials
(glass, plastic, rubber, any non-ferrous metals, etc.) such as
automobiles and household appliances. Hardened steel hammers or
knives, driven by electric motors of enormous power, reduce the
object to small pieces that can then be sorted, mainly by magnets
that remove the steel scrap and leave all other material. Shredders
are usually very expensive to buy and run and are only
justified when huge numbers of objects are available to feed
through them. Most industrial countries have one shredding plant
for between two and five million people. Most non-industrialized
countries do not have enough motor vehicles or household appliances
to justify the installation of shredding plants.
Chemical Methods.  Used when metals are mixed (or mixed with nonmetals)
and not simply mechanically joined. Chemical methods are
often combined with electrolysis (the passing of an electric
current through a solution containing the metal compounds).  Important
examples are:
     *     detinning of tin plate scrap
     *     recovery of silver from photographic wastes. This will
          be described under IV. PRECIOUS METALS below.
"Tin" cans are actually made of steel coated with a very thin
layer of tin and often with lacquer as well.   They are a problem
to steel makers as the tin, which has a lower melting point,
causes zones of weakness in the hot steel, leading to hot shortness"
and other problems.  For this reason, cans are not used by
steel makers in the industralized countries unless the tin has
been removed (or at least reduced) by detinning. Alternatively,
their use is restricted to the production of low-quality products
such as reinforcing steel.
In many developing countries where there is a shortage of steel
scrap, used cans are accepted, provided they form less than ten
percent of the total scrap charge and are evenly dispersed
throughout: one steelmaker claims to use up to 50 percent cans to
make reinforcing bars!  Some steel makers prefer cans rusted in
the weather for some weeks before use.
In the original manufacture tin is applied to the steel sheet by
either of two industrial processes.   The more modern is electrolytic
deposition, which results in an extremely thin layer of tin
(thickness 0.0015mm and weight 0.5 percent to 1.0 percent). In
the older process, the steel was dipped in a bath of molten tin
resulting in a much thicker layer of tin: by weight 1.5 percent
to 7.0 percent. Hot dipped tinplate scrap causes worse contamination
in steelmaking.  Also, the amount of pure tin that can be
recovered from it is greater, which makes the removal process
more profitable. Detinning is applied to scrap from can manufacturing,
but because they are dirty, which upsets the process,
only occasionally to used cans.
Detinning of Scrap Tinplate
This can be carried out in countries where tinplate cans and
boxes are locally manufactured in volume and where local steel
rolling mills or foundries export the steel scrap. Local markets
for tin are not essential as this metal can be sold internationally.
It finds virtually unlimited markets if the quality
is correct (this means composition of not less than 99.75 percent
tin).  If it is contaminated with lead (which often occurs in
can-manufacturing scrap) it may be sold for solder manufacture at
only slightly lower prices.
Detinned steel scrap, if it is press-packed into rectangular
bales in a hydraulic press, fetches almost the highest price that
is paid for steel scrap.  The tin content must be kept to below
0.05 percent but this is not difficult using the process described.
The major items of such a plant are a furnace constructed of
brick, with flues and grates firebrick-lined, containing mild
steel vats about one meter deep and in diameter, complete with
chimney and forced draft fan.   Around the furnace is arranged a
low voltage electrical distribution system, to make the vat slide
into a cathode.  The anode is retractable so that it may be
lowered to make electrical contact with the scrap charge and
raised clear when the charge is positioned or withdrawn. A crane
to handle the full charge baskets is needed, as are pre-wash and
post-rinse water tanks, a tin smelting furnace and refining
furnace with hand tools, and a scrap metal baling press. The
process requires a competent standard of technical and commercial
Economics of Detinning
These will vary widely depending on local factors and, in particular:
steel scrap prices, local electricity tariffs, cheap fuel
availability, location and transport arrangements, and whether
tin metal can be sold locally. However, based on actual costings
for a 6,000 ton per annum plant in East Africa in 1981 it appears
     *     At a scale of over 1000 tons per annum a detinning
          plant of this kind can operate at a profit, given
          typical costs and prices for developing countries that
          have their own steel industry.
     *     Profitability is substantially higher if the thickness
          of tin coating is greater, for example, where cans are
          made for export of acid fruits.
     *     Between 250 and 1000 tons per annum plants are only
          profitable if tin coatings are thicker than those used
          for non-corrosive contents.
     *     Below 250 tons per annum, micro scale plants make no
          significant profit but can provide self-financing employment.
However, these principles are general; each country's individual
situation should be studied.   Table 4 presents a comparison of
the investment required and returns expected on various sizes of
small detinning plants.
Table 4. Investment and Profitability of Small Detinning Plants
             (All figures in thousands of U.S. dollars)
                                     Plant Capacity in Tons per Annum
                                       50       250     1000     6000
Capital costs                            13      45       127      396
Sales - Baled detinned steel             3       15         60     360
      - Tin metal (0.5 percent)         3        16         63     378
Total variable costs                     4       17        57      300
Total fixed costs                        2        7        20      70
Total costs                              6         24       77      370
Net profit before  tax                  0          7        46     368
Return on investment before tax          0        15        36      93
Number of workers                        1         3         8      32
The junk motor car is an important source of steel scrap in developing
countries. It is fully discussed in Jobs from Junk (See
Car parts can be recovered by removal and sale of some components,
use of parts for scrap, and use of the shell for scrap.
Recovery of Saleable Components
Parts are worth much more when re-used rather than scrapped.
Every city in the world has dealers in second-hand car parts and
in some towns a complete commercial district is devoted to nothing
Recovery for Scrap
Unsaleable parts can often be used as raw material, e.g., leaf
springs can be cut and ground to make excellent chisels and hoes.
What is unusable goes for scrap: engines as cast iron or aluminum,
radiators as copper, etc.
Recovery of Auto Shells
The shell is all that remains of the car when the parts have been
removed. Shells abound in many parts of the Third World, not
only in cities and suburbs but also in rural areas.   They are a
hazard to traffic and to children and serve as breeding areas for
mosquitoes and other pests.  However, their large size and low
weight of metal make them uneconomic to transport to a distant
steel mill or foundry.  Neither are there sufficient numbers to
justify investment in hugh car-crushers or shredders such as
those used in the industrialized countries.
Because people in some Third World countries are so resourceful
in car repair and obtaining used spare parts, cars often run for
30 or 40 years, also diminishing the scrap supply.
Where large numbers of shells are accumulating, simple labor-intenstive
methods may be used to reduce them to pieces small
enough for economic transport to the scrap buyers.
Metals other than iron and steel are described as non-ferious.
The most interesting as regards scrap are aluminum, copper,
brasses and bronzes, zinc, and lead.
One problem facing the collector is how to identify all these
different metals. They are used by quite different markets and
the best prices are paid by the final users, normally foundries
or refiners, who will not buy mixed or unidentified metals.
There are simple tests to identify a metal:
     *     Find out where it came from
     *     Consider the size, shape, and former use of the item
     *     Test it with a magnet; ferrous metals are attracted by
          or to it; non-ferrous metals are generally not
     *     Look at the color
     *     Drill or take filings.
Copper is the perfect material for recycling.   It is valuable,
easy to identify, easy to clean, and heavy. Moreover, it can be
readily sold to small foundries or larger companies that refine
and produce copper sheet, wire, or bars. It has many important
alloys, particularly bronze (which contains copper, tin, and
zinc) and brass (which contains copper-and zinc only).   Scrap
from either is easy to sell.
Grading of Copper Scrap
Copper may be graded as follows:
     *    Pure copper
     *    Copper cables with plastic covering.   The plastic or
         rubber covering has to be removed and this can be done
         in one of three ways: by hand, by burning, or by using
         a cable stripper--a machine that chews off plastic,
         leaving the copper wire unharmed.
     *    Copper contaminated with tin
     *    Copper contaminated with solder
     *    Electrical machinery
     *    Chromium-plated copper.
Refining of Copper Scrap
This needs specialist skills.   The copper is furnace-melted and
molten sand added to form a slag.   Air is blown into the molten
mixture and iron, tin, and lead are all oxidized and float in the
slag.  Cadmium, sulphur, and other impurities are then given off
as gases. Some of the copper also becomes oxidized and has to be
reduced by poling: floating green tree trunks in the hot molten
copper (as in the smelting of copper ore).
Casting of Copper into Ingots
In a foundry, pure copper can be melted in any of the small furnaces
described above, and cast into ingots. It is worth investing
in cast iron molds. Special equipment to measure the furnace
temperature is necessary and specialist advice should be obtained
if possible.
Sources of Aluminum Scrap
Aluminum is one of the most widely used metals because it is
cheap to produce, lightweight, and very easy to work. The main
sources are:
    *    cooking pots
    *    car parts
    *    airplane parts
    *    domestic appliances
    *    tubes, boxes, containers for medicines and other packaging
    *    door and window frames
    *    electric cable
    *    some drink cans
    *    cooking foil, take-away food trays and milk bottle
Markets for Aluminum Scrap
In developing countries the largest market will be small foundries,
but there may also be mills that melt the scrap to produce
ingots for conversion into sheets, extrusions, castings, etc.
Most of these will buy aluminum scrap if its composition is
known, but may refuse to buy foil unless baled.   Foil may also be
sold to steelmakers, who use it as a deoxidant; it is ground and
thrown into the crucible to reduce slag.
Grading of Aluminum
When collecting, keep known alloys separate from commercially
pure aluminum. Thereafter, the main task is to remove all non-aluminum
materials such as plastics, oil, iron or steel, copper,
dirt, or the contents of containers.
The aluminum is then graded to:
    *    clean heavy
    *    dirty or "irony" heavy
    *    foil and other thin material such as cans and containers.
Manufacture of Aluminum Ingots
The market for aluminum scrap can be improved by casting ingots.
A furnace is needed with a sloping hearth capable of reaching
temperatures 200-300[degrees]C above that at which aluminum melts
(660[degrees]C.)  The aluminum will melt before any ferrous metals. and
will run down the furnace hearth into a trough, from which it may
be poured into open sand molds. The ferrous metals remain on the
hearth, avoiding the need to remove them from the scrap beforehand.
For suitable furnaces, see 'Equipment Suppliers' at the
end of this paper.
An Aluminum Foundry
Having successfully cast aluminum ingots, it may be possible to
cast finished products.  This is not, however, an easy process
and some knowledge of foundry operations is vital.   Of the furnaces
described above, the rotary, induction, or crucible may be
used for aluminum.
It is possible to sand-cast aluminum in a manner similar to cast
iron, but, as aluminum is often used to make smaller components
in far larger numbers, it may be economic to use die-casting.
This replaces the sand mold with one of steel, accurately machined
and expertly designed, so that the metal will flow, solidify,
and shrink correctly.  Therefore, dies can be extremely
The simplest process is gravity die-casting: the metal is ladled
into the heated die and the only pressure is from its own weight.
A more complicated but faster process uses a pressure die-caster
that forces the molten metal into the die, ejects the finished
casting, and closes the die ready for the next cycle.
Zinc is a cheap, easily-cast metal used for castings where
strength is not important.  It is widely used for galvanizing
(protecting steel from rusting) and making brasses alloys of
copper and zinc).  Zinc casts easily and is widely used for die
castings but not all factories with die-casting machinery can use
zinc scrap. Metal of high purity is required and is alloyed with
carefully controlled additions of aluminum (and sometimes copper).
Zinc can easily be melted in a furnace at 400' to 500[degrees]C with a
chloride flux, but the metal obtained may not be pure.   Almost
pure metal can be obtained by evaporating the metal in a controlled
atmosphere and collecting the vapor in a condenser (a steel
drum, cooled by water will do) from which it may be remelted and
cast into ingots.
Products made from zinc include:
    *    parts for cars (especially door handles, brackets,
        casings for small gear boxes, carburetors, etc.
    *    washing machines and refrigerators
    *    slot machines
    *    radios and televisions
    *    oil burners
    *    printers' plates and type.
Lead, like copper, is an easy material to recycle if only you can
obtain enough of it.  Its grey color when oxidized, great density,
softness, and flexibility make it easy to identify.   These
same properties make it valuable. It is easy to store, transport,
and work into its final shape.   Because it melts at a low
temperature (325[degrees]C) no special furnace is needed and it is cast
by any industry that uses it.   Thus, the sources of lead scrap
are also the markets into which you can sell it, for example:
    *    car battery plate solder
    *    pipes for plumbing
    *    flashings (waterproof joints) for roofs
    *    gutters and spouts for rainwater
    *    weights and counter-weights
    *    wine bottle tops and seals
    *    bearings of white metal (lead and tin)
    *    printing metals
    *    lead covered cable.
Although lead is easy to melt, care is needed to ensure that as
little lead scrap as possible is lost as fumes and dross (rubbish
that floats on the molten metal).   This can be achieved by using
a flux and a reducing agent. The scrap is first washed in a
concentrated solution of sodium carbonate, to remove sulphur, and
then smelted in a furnace at 800[degrees]-900[degrees]C, using coke as the reducing
agent, and flux of soda ash, borax, and fluorspar.
        Lead is a poison and can cause fatal illness.
Any workshop handling molten lead should have fume extraction
 fans fitted and employees should wear effective face masks,
 wash before eating, and have regular medical examinations.
Normally these are recycled by gold- and silversmiths. There is,
however, one important source of silver available to the public:
the recovery of silver from photographic materials.
The silver present in a wide range of photographic and X-ray
materials can be recovered as metal and sold.   The materials in
questions are of two kinds.  First, there are those used to
process photographs and x-rays, in particular, fixer solutions.
Silver is also contained in the actual photographs and x-rays
themselves, after they have been developed.   It can only be
recovered by destroying them when they are no longer required.
In a photographic or x-ray film, silver bromide grains are contained
within a layer of gelatin known as emulsion.   The
gelatin is thinly spread on a sheet of transparent plastic film,
known as the support.  When the light from a camera lens falls on
the film, the silver bromide grains are sensitized in the same
pattern as that of the light.   The places that receive the most
light have the most grains sensitized and, after developing,
contain the greatest amount of silver.   The silver is not in the
bright, shiny, metallic form with which we are familiar in jewelry
and cutlery, but has the appearance of a fine, black or dark
grey powder. Thus, the areas that were exposed to the most light
become darkest and such film is called negative.
The grains of silver bromide that have not been converted to
silver are next removed by making them soluble in water, by
treating them with a fixer.  This is a solution containing a
chemical: most commonly sodium thiosulphate, often known as hypo.
After fixing, the negative is washed and all the soluble silver
thiosulphate removed, to leave only the metallic silver in the
emulsion. To convert from the transparent negative to a positive
print, print paper coated with emulsion on a paper backing is
exposed to light that has passed through the negative.   The
exposed paper is then developed, fixed, and washed in exactly the
same way.
It will be seen that a large proportion of the silver, which
begins life as silver bromide within the photographic gelatin, is
removed during the fixing process.   If only a little light fell
on the film, almost all the silver will end up in the fixer. If
a large amount of light fell, most of the silver will remain
within the gelatin on the film.   There are, therefore, two
significant procedures for recovering silver from x-ray and photographic
wastes: first, to extract it from the spent fixing
bath, and second, to recover it from the film, when this is no
longer needed.
X-rays behave exactly like rays of light and identical emulsion
and support can be used for x-ray film, although it is common for
the support to be coated with emulsion on both sides, whereas in
photography, only one side is coated.
There is an important difference between color and black-and-white
photography from the point of view of the recovery of
silver.  Whereas in black and white or x-rays a large percentage
of the metallic silver remains within the emulsion, in color
photography it is all removed, in a solution called bleach-fix.
Color bleach-fix may therefore be very rich in silver but is
rarely available outside laboratories.
From Spent Fixer Bath
There are a number of ways in which metallic silver can be recovered:
Electrolysis.  A small direct electric current is passed through
the fixer so that the silver is plated onto the cathode from
which it can later be removed.
Metal Ion Replacement.  The silver in the solution is replaced by
a more reactive metal such as zinc or iron.
Chemical Methods.  Chemicals are added to the fixer, which precipitates
either silver or an insoluble silver salt, which is then
extracted by filtering, contrifuging, etc.
From Film
It is only necessary to release the silver from the emulsion.
There are four principal ways in which this may be done:
     1.    By burning the support film and gelatin to leave a
          silver-containing ash, which can be reduced to silver
          metal. This creates air pollution and much of the
          silver is lost as smoke.
     2.    Oxidizing the silver to a soluble oxide, which can be
          washed out of the emulsion.
     3.    Dissolving the gelatin using an enzyme (a biochemical
          substance) of the proteolytic (which means protein
          eating) type or an acid or alkali and then recovering
          the pure silver from the residual sludge.
     4.    Reversal of the silver grains back to silver bromide,
          followed by dissolving in a fixer and electrolytic
     *     advertising agents, newspapers, cinema, television
     *     photographic services, aerial photography, aerial surveys
     *     engineering contractors, foundries, welding laboratories
     *     film studios
     *     clinics, dentists, hospitals
     *     laboratories, micro-filming services
     *     x-rays and film manufacturers and stockists
The space can be unroofed but non-ferrous metals, which are
valuable, should be secure from theft. Because the process is
ugly, screening by belts of trees or fences is common.
Stockholding Finance
Prices for  the sale of recycled metals increase as the quantity
delivered increases. To achieve these improved prices it is
necessary to finance purchasing and collection (and often the
preparation and further processing) before any sale is made.
Knowing the Customer. Dealers in scrap metal sell to a small
number of large and powerful customers and are often in competition
with many other scrap metal merchants. This weak bargaining
situation can be overcome only by knowing the customer and his
business. The merchant should understand what each different
grade of scrap is used for and keep himself informed of changes
in the supply and demand of this product so that he can predict
shortages (and high prices) and surpluses (low prices).
Knowing the Collectors and Suppliers.   For supplies of material
the dealer is dependent on:
     *     industrial producers of scrap who want regular collection
           to keep their premises clear, prompt payment,
           and no fuss, and
     *      gypsies and scavengers who want fair prices and prompt
           payment--or often advance loans or help with purchasing
           hand-carts, etc.
Knowledge of Metals. The dealer must be able to distinguish different
grades of metals at a glance or know what tests to apply.
Commercial Management Sense. Especially when handling liquidity
--ensuring enough cash to pay today's suppliers and labor even
though the scrap may not be sold for days or weeks ahead.
Ability to Manage and Operate Plant. Small-scale scrap handling
can be done by hand but for the enterprise to grow, machinery is
essential: mechanical, electrical, and hydraulic systems to work
under very rugged and difficult conditions. The successful scrap
merchant must be able to obtain the services of qualified mechanics,
obtain or stock necessary spare parts, operate regular
maintenance schedules, etc.
Awareness of International Markets. Knowledge of the grades of
scrap in which the merchant deals and the economics of selling
to international markets when prices are depressed.
The main costs of collecting, dealing, and processing scrap
metals are:
Purchasing     -       scrap from suppliers.
Transportation -      both to the sorting yard and from the yard to
                      the customer (or to the docks for export).
                      The economics of iron and steel scrap are
                      dominated by transportation costs as the
                      tonages and volumes are so large.
Energy Costs   -       such as cutting gases, electrical power, or
                      furnace fuel.
Labor Costs    -       in industrialized (high wage) countries are
                      significant unless reduced by heavy investment
                      in capital equipment. In developing
                      countries, both these costs will be lower.
Value Added    -       profitability is higher if the dealer produces
                      a finished or partly finished product.
                      For example, a factory in Papua New Guinea
                      that  recycled lead found it more profitable
                      to cast fishing weights, which they sold
                      direct to marine stores.
Scrap Metal    -       vary from one week to the next and from
                      Prices one country to another. Changes in
                      international markets may be found by consulting
                      Materials Reclamation Weekly and
                      Metal Bulletin (See bibliography). Table 1
                      above gives current prices in Britain which
                      may be used for guidance only to show how the
                      values of different materials compare. It is
                      stressed that local prices may differ from
                      these by many hundred percent and anyone
                      dealing in scrap metals must obtain local, up
                      to date commercial information.
Unsuitable technology can kill a promising scrap metal (or any
other) business. Technology should be introduced in three
phases. Only when one phase has been fully mastered, free of
technical and maintenance problems for at least a year, and shows
a clear profit should the next phase be started. The phases are:
Phase 1
Establish suppliers, markets, and scrap grading operations, using
manual labor and simple vehicles.
Phase 2
Merchandise scrap handling and sorting, using:
     *     skip-loader vehicles and skips, or trucks with hydraulic
          grab cranes for collection
     *     cranes with hydraulic or magnetic grabs for sorting
     *     shearing and baling machines for scrap preparations.
Phase 3
Further processing of selected kinds of scrap in foundry, forge,
etc., to add value to the product.
Before Phase 1 is started the decision must be made on what kind
of metal to recycle. The decision will affect the whole operation
for years to come and should be based on:
     *     a survey of the markets for scrap metals or products
          that can be made from them
     *     a survey of the available supplies
     *     a calculation of the volume of metal that car be
     *     a feasibility study (calculation of the likely costs
          and income showing whether the business will have good
          cash flow and profitability) in all three phases.
Dealers in scrap metal may be particularly affected by three
kinds of law:
Export restrictions
Scrap metals are often so important to a country's economy that
they may not be sold overseas. There may be restrictions on
imports of processing machinery and fuels.
Some scrap metal, especially copper, used for telephone and
electric power cables, is frequently stolen. Police after, control
this by requiring scrap dealers to be licensed and to record
every purchase they make. The municipality or police may be the
licensing authority.
Safety of Employees
Handling scrap metal is dangerous! In many countries the, law
requires the employer to safeguard his employees from all such
dangers by providing safe working methods, protective clothing,
medical checks, etc. Even if no laws apply, the victim of an
accident may have legal rights to sue the employer for negligence.
The dangers are very widespread and include:
     *     fire
     *     injury from falling objects
     *     injury and disease from poisonous chemicals and gasses
     *     explosion (of gasoline tanks, gas cylinders)
     *     burns and scalding, and
     *     infection of wounds.
Alexander and Street. Metals in the Service of Man, Penguin
     Books, Ltd., Bath Road, Harmondsworth, Middlesex, UB7 ODA,
     United Kingdom.
Gross, John A. Metal Forging and Wrought Iron Work, Mills and
     Boon Ltd., 17-19 Foley Street, London Wla, 1DR, U.K.
Harper, John. Small Scale Foundries. Intermediate Technology Publications
     Ltd. 9 King Street, London WC2E 8HW, U.K.
Intermediate Technology Development Group. The Iron Foundry--An
     Industrial Profile, Intermediate Technology Publications
     Ltd., 9 King Street, London WC2E 8HW, U.K.
Intermediate Technology Development Group. Jobs from Junks: How
     to Create Employment and Tidy Up Delerict Cars. Intermediate
     Technology Publications Ltd., 9 King Street, London WC2E
     8HW, U.K.
Intermediate Technology Development Group. Oil Drum Forges. Intermediate
     Technology Publications Ltd., 9 King Street,
     London WC2E 8HW, U.K.
Materials Reclamation Directory, P.O. Box 109, Maclaren House,
     Scarbrook Road, Croydon CR9 1QH, U.K.
Materials Reclamation Weekly, P.O. Box 109, Maclaren House, Scarbrook
     Road, Croydon CR9 1QH, U.K.
Metal Bulletin, 45, Lower Marsh Street, London SE1, U.K.
National Association of Recycling Industries. Recycled Metals in
     the Nineteen Eighties, National Association of Recycling Industries
     330 Madison Avenue, New York, New York 10017 USA.
Small Industry Research Institute. Several reports, Small Industry
     Research Institute. P.O. Box 2106, 4/43 Roop Nagar,
     Delhi 110007 India.
Stimpson and Gray. Foundry Work, American Technical Society,
     Chicago, Illinois USA.
United Nations Industrial Development Organisation. Guidelines
     for Establishing Demonstration Foundry in a Developing
     Country.   UNIDO, Felderhaus, P.O. Box 707, Rathausplatz 2,
     A-1010, Vienna, Austria.
                          EQUIPMENT SUPPLIERS
Foundry Equipment
Pioneer Equipment Co., Ltd.
Old Padra Road,
Akota, Baroda
Gujarat, India
Gas Cutting Torches
British Oxygen Co., Ltd.
W. Pimbo, Skelmersdale, U.K.
Metal Scrap Machinery
J. McIntyre (Machinery) Ltd.
Acorn Park Industrial Estate
Harrimans Lane, Dunkirk
Nottingham, U.K.
Vanesco Ltd.
165 Garth Road
Morden Surrey, SM4 4LH U.K.
Hydraulic and Engineering Works
10066, First Floor
D.B. Gupta Road
Pahar Ganj, New Delhi 110055, India
Hindustan Brown Boveri Baroda Ltd.
264 Dr Annie Besant Road
Bombay 43005 India
G.E.C. of India, Ltd.
Chitarajan Avenue
Calcutta, India
Rerolling Mills
Mukand Iron and Steel works
Belapur Road
Kalvew, Thana
Maharashtra, India
Davey Ashmore India Ltd.
Kharagpur G-19
Middleton Street
Calcutta, India
A.C.C. Vickers-Babcock Durgapur, Ltd.
Express Tower
18th Shahabad Floor
Nariman Point
Bombay 430021, India
Cable Strippers
G.L. Murphy Ltd.
Imperial Works
Menston LS29 6AA
W. Yorkshire, U.K.
Metpro Machinery Ltd.
North Road Industrial Estate
Bridgend, Mid Glamorgan U.K.
Aluminum Furnaces
Chine Furnaces
Units 4 & 5
New Road, Newhaven
East Sussex, U.K.
Silver Recovery
The X-Rite Company
4101 Rogers B. Chaffee Drive
S.E. Grand Rapids, Michigan 39508 USA
Photographic Silver Recovery Ltd.
Saxon Way
Royston Herts SG8 6DN, U.K.
Vogler, Jon. Detinning. INTERWASTE, 40 The Avenue, Roundhay,
Leeds, LS8 1JG, U. K.
Weygers, Alexander, G. Forging by Hand, Van Nostrand Reinhold
Co., 450 West 33rd Street, New York, New York 10001 USA.
Weygers, Alexander G. Recycling, Use and Repari of Tools, Van
Nostrand Reinhold Company. 450 West 33rd Street, New York,
New York 10001 USA.
1.  British Secondary Metals Associations, 40 Oxford Street,
London Wl, United Kingdom. Telephone 01-580-5228.
2.  British Scrap Federation, 16 High Street, Brampton, Huntingdon,
Cambs PE18 BTU, United Kingdom. Telephone: 0480-55249.
3.  Bureau International de la Recuperation, Place du Samedi,
13-BTE 4, 1000 Brussels, Belgium. Telephone (02) 217-82-51.
4.  Interwaste, 40 The Avenue, Roundhay, Leeds LS8 1JG, United
Kingdom Telephone: 0532-661885.
5.  The Institute of Scrap Iron and Steel, Inc. 1627 "K" Street
N.W., Washington, D.C. 20036 USA
6.  National Association of Recycling Industries, 330 Madison
Avenue, New York, New York 10017 USA