CA2072778A1 - Disposal method for organic and inorganic nonmetallic ancillary materials from used vehicles, used appliances and the like - Google Patents

Abstract

ABSTRACT
An environmentally advantageous method for disposal of organic and inorganic nonmetallic ancillary materials from used vehicles or other mass-produced products, such as washing machines or refrigerators, uses the waste substances as chemically reducing and slag-forming fluxes in the smelting of iron ore in a blast furnace plant or in the production of steel or cast iron in a cupola furnace plant to at least partially replace the substances normally used as fluxes.

Description

2 ~ 7 8 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 :: . '~ ' , ~

2~2 iJ~8 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 '' , ~: ' . '' :`

2 ~ 7 ~ d ~ 3 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 . .

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 2~7~

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.

Claims (3)

1. A process for disposing of discarded products including used vehicles and scrap-containing used appliances, comprising the steps of first removing at least one separately recyclable or treatable valuable substances, hazardous substances and substances which interfere with recovery of steel or adversely affect steel quality removed from the discarded products, preparing the discarded products partially demounted in the first step but still containing ancillary materials constituting 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 for a recovery of steel scrap they contain, introducing the ancillary materials and steel scrap into a furnace and melting the steel scrap in a furnace with the addition of chemically reducing and slag-forming fluxes, wherein, as a result of being fed into the furnace together with the steel scrap from the discarded products, the ancillary materials are chemically reacted therein with iron oxide contained in one of the steel scrap and iron ore and act as chemically reducing and slag-forming fluxes to at least partially replace conventional fluxes.

2. The process according to Claim 1, wherein the step of preparing includes baling the partially demounted discarded products in a scrap press together with the ancillary materials contained in the discarded products and the step of introducing includes feeding the scrap bales into the furnace.

3. The process according to Claim 2, wherein each of the baled discarded products is adjusted to a defined quantitative ratio of steel scrap and ancillary materials which is equal in size for all the discarded products of different types by adding one of a type-specific weighed mixture of ancillary materials of different origin, a type-specific weighted amount of plastic waste and, in the event of the proportion of scrap being too low, of preferably shredded steel scrap to each of the discarded products after partial dismantling thereof but before baling.