Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUN~ AND SUMMARY OF TXE INVENTION
The present invention deals with an environmentally
advantageous method for disposing of organic and inorganic
nonmetallic ancillary materials from used vehicles and
other mass-produced products such as washing machines,
refrigerators, and the like. In particular, the present
invention relates to a process for disposing of used
vehicles or scrap-containing used appliances after they are
finally discarded, in which process separately recyclable
or treatable valuable substances or hazardous substances
and/or substances which interfere with the recovery of
steel or adversely affect the steel quality are first
removed from the used vehicles or used appliances. The
used vehicles or used appliances partially demounted in
this way, but still containing most of the parts or
substances which were originally built into the vehicles or
appliances or mounted on them and which consist of organic
and inorganic nonmetallic materials (hereinafter referred
to as "ancillary materials" for short), are then prepared
for a recovery of the steel scrap they contain. Finally,
the ancillary materials are disposed of and the steel scrap
is melted in a blast furnace or in a cupola furnace
(hereinafter referred to as a "shaft furnace" for short)
with the addition of chemically reducing and slag-forming
fluxes.
In disposing of used vehicles, the latter are first
partially demounted by scrap vehicle dealers, in which
process, for example, operating materials such as oil,
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brake fluid and coolant, engine and gearbox, miscellaneous
aluminum and light-metal parts, exhaust gas catalyst (if
applicable), electrical storage battery, cable harness,
installed electric motors and the generator, the tires, and
fairly large, systematically selected, readily demountable
plastic parts which consist basically of a particular
thermoplastic and whose material, when classified according
to type, can be reused are in all cases removed from the
used vehicle and these substances or parts are separately
disposed of, treated or recycled. All of the above listed
components are not, however, demounted by all scrap vehicle
dealers. According to generally widespread opinion, the
used vehicles, more or less comprehensively partially
demounted in this way, have to be separated from the
organic ancillary vehicle materials still remaining in them
before the steel scrap can be recovered by smelting.
In disposing of other mass-produced products, such as
washing machines, ~ishwashers, dryers or refrigerators (the
so-called "white goods" of the electrical industry) the
procedure is in principle similar. To separate steel scrap
and non-steel scrap, the partially demounted used vehicle
or other used appliance have to be cut up (i.e. shredded)
into small parts by scrap cutters. The small parts can
then be sorted into heavy, in particular metal, parts and
light plastic parts. In this process, the steel parts are
first picked out of the heavy fraction by magnetic
separators, and the nonferrous metals, in particular the
light metals, are manually picked out of the remainder; the
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remainder then still left over contains mainly the
nonmetallic inorganic substances such as glass, porcelain,
ceramic or the like.
As a result of the very large number of used vehicles
or used appliances to be scrapped annually, a
correspondingly large amount of organic and inorganic
nonmetallic ancillary materials is produced. Disposing of
these ancillary materials presents more and more problems.
In disposing of more modern used vehicles, this proportion
already amounts to about 20 to 25~ by weight of the total
weight of the used vehicles. A very wide variety of iron
and steel parts is encountered in partially demounted used
vehicles, for example, deep-drawn sheet-metal parts having
various wall thicknesses (some galvanized), forged parts
(some hardened), grey cast iron and cast steel parts, parts
made of alloyed and hardened steel, for example springs, or
corrosion-resistant alloy steels.
The above-mentioned organic ancillary materials
mentioned ar~ essentially thermoplastics and thermosetting
plastics of every composition, used or processed in the
form of, for example, film, moulding or foam, elastomers,
in particular rubber parts, for example used tires or
lengths of hose, textiles made of synthetic and/or natural
fibers, lacquer or paint coatings, oil or fuel residues,
wooden parts, paper or cardboard parts, parts made of
cellulose fibers, and parts made of mixtures of these
substances or composite parts made therefrom.
The inorganic nonmetallic ancillary materials are
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primarily glass, porcelain, ceramic (insulators), enamel
coatings, adhering sand or soil, and entrained stones.
In the longer term, disposal of this so-called
shredded refuse in refuse disposal sites is no longer
possible because the disposal space available in the
foreseeable future is continuously decreasing. Combustion
or thermal disposal of such waste is comparatively
expensive because of the clean air requirements and the
investment and operating costs necessary for this purpose,
particularly if operation is to be really emission-free in
every respect. Still more stringent environmental
requirements may be imposed by legislators in the future
and will have also to be observed.
More recent attempts to utilize the organic and
inorganic nonmetallic ancillary materials in a smelting
reactor for smelting the vehicle scrap as an energy source
in order to partially replace the energy carrier for the
smelting energ~ are unconvincing because the slag produced
in this process contains a very high proportion of iron
oxide. This high iron oxide content represents, on one
hand, a loss in yield in the production of steel from the
scrap and, on the other hand, a utilization or disposal
problem for the slag because the slag containing large
amounts of iron oxide contaminates the ground water.
An object of the present invention is to provide a
suitable, different, acceptable and environmentally
advantageous method of disposing of the organic and
inorganic nonmetallic ancillary materials from used
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vehicles and/or used appliances scrapped in large numbers
by the users.
Starting from the known basic process, the foregoing
object has been achieved, according to the present
invention by feeding the ancillary material into the shaft
furnace together with the steel scrap from the used
vehicles or used appliances, the ancillary materials are
chemically reacted therein with the iron oxide contained in
the steel scrap or iron ore, and serve as chemically
reducing and slag-forming fluxes so as to, at least
partially, replace conventional fluxes for this purposes,
such as coke, oil or gas.
It is recommended that the organic and inorganic
nonmetallic ancillary materials are used in the present
invention as chemically reducing and slag-forming fluxes in
the smelting of iron ore in a blast furnace and/or in the
smelting of steel scrap in a cupola furnace. Surprisingly,
the analysis of the organic and inorganic nonmetallic
ancillary vehicle materials enco~lntered in the normal
scrapping of used vehicles (hitherto separately) yields a
composition which not only does not interfere with the
blast furnace or cupola furnace process but even assists it
because the organic materials can readily be used as
carbon-containing reducing agents for deoxidizing the ore
or the rusted or corroded steel scrap, if they are not
suitable as sources of carbon, the elastomers make a
contribution in supplying the required smelting energy, and
the inorganic nonmetallic components contribute to the
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required slag formation.
To promote the required slag formation in the shaft
furnace process, the inorganic nonmetallic parts of the
used vehicles or used appliances, in particular glass, are
also used or exploited and in this way disposed of in an
environmentally advantageous manner, and are converted into
blast furnace slag which can be processed further and
constitute, under some circumstances, a valuable substance.
For this purpose, therefore, the glass and ceramic parts of
the products such as used vehicles or appliances are
excluded from the partial dismantling of the products, i.e.
they are left in the used vehicles or appliances to be
smelted.
The process of the present invention thereby makes it
possible to achieve a whole series of advantages, namely:
(a) an environmentally advantageous disposal of the
organic ancillary vehicle materials;
(b) reduction of the amount of refuse to be dumped
and, consequently, removal of load from the
refuse disposal sites;
(c) reduction of the amount of refuse to be
incinerated and, consequently, removal of load
from the refuse incineration plants;
(d) reduced usage of the resources in conventional
chemically reducing fluxes and/or fluxes
supplying smelting energy in steel smelting, such
as coke, oil or gas;
(e) care of the environment due to an overall
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reduction in the production of carbon dioxide;
(f) utilization of the waste-gas purification plant,
which is in any case installed in a shaft furnace
plant for ore smelting or for producing steel or
cast iron from scrap, also for purifying the
exhaust gases produced in the chemical conversion
of the organic and inorganic nonmetallic
ancillary materials accompanying the steel scrap;
tg) eliminating the need for an expensive shredder
for the partially demounted used vehicles or used
appliances; the latter can be baled more
ef:Eiciently and more inexpensively;
(h) eliminating the need for the e~ually cost-
generating sorting ox separation of steel scrap
and other ancillary materials;
(i) opening-up of environmentally advantageous,
acceptable disposal channlels for shredded refuse
produced in hitherto already existing scrapping
plants, in particular for vehicles and consisting
of organic and inorganic nonmetallic ancillary
materials, or for other plastic or elastomer
wastes, in particular used tires, collected or
produced in other ways.
DETAILED DESCRIPTION OF THE INVENTION
It is readily possible to continue to operate the
shredder plants already existing at scrap vehicle dealers'
premises as well, although as a result of the present
invention the shredded scrap now no longer needs to be
sorted into steel and nonmetallic substances, but the
mixture of the two can be delivered to the steel producers
or foundries which operate a blast furnace or cupola
furnace. Sincet however, scrap presses are more
advantageous than shredding plants in relation to
investment and operating costs, it is expedient to bale the
partially demounted used vehicles or used appliances
together ~ith the organic and inorganic nonmetallic
ancillary materials they always contain in a scrapping
press and to submit these scrap bales to the smelting or
steel-smelting or cast-iron production process.
Depending on the site of a blast furnace plant in
terms of economic geography and on the site-specific type
and quality of the raw materials available at it and to ~e
processed accordingly, the qualitative and quantitative
composition of the substances or burden to be loaded into
the blast furnace (the so-called Moller in German-speaking
areas) may vary very widely from site to site. However, a
particular blast furnace is always loaded with a burden of
similar composition which remains approximately constant
with time. To ensure that a furnace operator who processes
scrap originating from used vehicles can expect
approximately constant conditions in relation to the
composition of the shaft furnace feed when smelting scrap
originating from completely different used vehicles, each
of the baled used vehicles or used appliances is
advantageously adjusted to a defined quanti~ative ratio of
steel scrap and organic and inorganic nonmetallic ancillary
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materials. Thus quantitative ratio is equal in size for
all the used vehicles or appliances of different types, by
adding in each case a type-specific weighed mixture of
plastic or elastomer waste and used glass or (should the
proportion of non-iron in the bale be too low) of
preferably shredded steel scrap to each of the used
vehicles or appliances after their partial demounting but
while they are still unbaled.
In an experiment performed by the applicant, the
composition of the partially demounted used vehicles (these
were used Mercedes-Benz "190" vehicles) was as follows:
Total weight of the partially
demounted used vehicle: approx. 730 kg
steel and iron therein: approx. 540 kg
including traces of copper (0.25~)
and tin (0.01~)
organic components : approx. 140 kg
inorganic nonmetallic component:s : approx. 30 kg
aluminum : approx. 20 kg
The aluminum (about 3.8% of the steel scrap
introduced) contained in the scrap bale in the example is
not alloyed into the steel produced but burnt in the blast
furnace, and is utilized as an energy carrier in the
process. The aluminum oxide also forms slag. The
nonferrous metals present in the iron produced in traces
are not troublesome in relation to the iron quality. Under
some circumstances, e~en beneficial effects can result in
relation to the corrosion behavior of the iron. In the
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scrapping of used vehicles by shredding, the small parts
are sorted into valuable substances such as steel,
aluminum, heavy nonferrous metals and into the nonmetallic
residue which could hitherto not be utilized, the so-called
shredder refuse which contains the organic components, that
is to s~y the plastics and rubber parts and the inorganic
nonmetallic components such as glass, sand, stones and
ceramic. Usually the proportion of inorganic nonmetallic
components is about 30% by weight of the shredder refuse,
relatively high, which is probably to be attributed
essentially to a demounting of the side windows of the used
vehicles which is only small in extent, which side windows
can be reused to produce glass bottles. In the above-
mentioned example, the proportion of the inorganic
nonmetallic components as a percentage is less than 30%,
namely about 18%, because the side windows had previously
been demounted in the case of the used vehicles mentioned
in the example.
Although the invention has been described and
illustrated in detail, it is to be clearly understood that
the same is by way of illustration and example, and is not
to be taken by way of limitation. The spirit and scope of
the present invention are to be limited only by the terms
of the appended claims.
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