DE2800224A1 - Non-ferrous metal separation from scrap agglomerate - uses salt bath with temp. exceeding that of non-ferrous metal - Google Patents

Abstract

The agglomerate is transported to the insulation by conveyor belt from which the pieces drop into vessel filled up to a level with a salt bath consisting of zinc chloride heated with burners. The correct temp. is monitored by thermometer assembly. The zinc melts in the bath and flows through the screen bottom of th container onto the inclined bottom of the container and towards the deepest point, where is collects. The melted zinc passes an adjustable overflow and is collected in vessel. The container is suspended from cables and is kept by intermediary of rod in swinging motion by a vibrator. Pieces which do not melt move along the screen bottom through opening into the collecting vessel.

Description

Method and device for separating non-ferrous metal from

sorted metal scrap batch The invention relates to a Method and device for separating non-ferrous metals from pre-sorted Metal scrap by heating in a liquid medium as a heat carrier a temperature exceeding the melting point of the colored detail to be separated, wherein the mixture of solid metal particles continuously in the liquid medium brought in and discharged again (DT-PS 15 83 879).

After shredding scrap steel or car wrecks fall under other steel and various non-ferrous metals such as A3, Mg, Zn, Cu, Ms and non-magnetic + hl. Some of the pieces consist of structural parts that are cast into one another or screwed, and which are not exposed. The steel and the construction parts with The predominant steel content is magnetically separated from the mixture, for the separation Sinking systems of Al and Mg are available and are used in practice Use in industry.

For the remaining heavy metals, mostly with a high Zn content such as Zn, Cu, Ns and also the non-metallic steel parts as well as the structural parts With a low proportion of steel, the melting process is known, but it is not a clean one Allow separation of the individual components, and because of the strong gas evolution lead to environmental pollution and today hardly any building permits are received.

As already mentioned, it is known according to DU-PS 15 83 879 that in one Liquid medium from a Cu-Pb mixture, the lead is melted out.

In practice, however, it has been found that the organic Liquids only at great risk to temperatures above the melting point of the Pb (2270C) could be brought, or. the melting of salt, such as those used for hardening Steel should be used because of explosion hazards, especially in the presence of Mg, offered no viable alternative. Namely, it can be used in practice do not avoid that the metal mixture contains a bit of magnesium can be. In addition, the temperatures required to melt zinc are much higher required because the melting point of zinc is 419 ° C. Salt baths therefore seemed experts generally consider it completely unsuitable for the smelting of zinc, It The object of the invention is to extract the zinc content in a molten bath from a mixture to be eliminated, even at the required temperatures, neither by outgassing can have a damaging effect on the environment through other circumstances and, above all, not is explosive, but on the other hand the zinc content also in coated Part completely separates.

The invention solves by a combination of the features of the preamble and the characterizing part of claim 1 the task set. In the group of the metal chlorides there are salts that on the one hand to zinc behave neutrally, even at the required temperatures, show a low level of exposure and neither with magnesium nor with other compounding residues of metal scrap rejoice. In particular, the solution according to claim 2 results in an outstandingly suitable one Bad through the use of zinc chloride.

The zinc separates completely, even with complex coatings, from the mixture and can be recovered almost 100%. With chrome-plated zinc parts The thin, shiny chrome skin is practically precipitated in the discharge, while the zinc completely has passed into the melt.

The use of the feature according to claim is of particular advantage 3, which is known per se for melting.

The feature of claim 4 is particularly suitable in combination with claim 5, since with the help of ultrasound the vibrations in a local limited area can be imposed on the mixture and thus an accelerated one Failure of the molten zinc is achieved.

With claim 6 an advantageous device is characterized, with which it is possible to remove the melted mixture from the melt pool and thus to work in the continuous melting process.

With claim 7 it becomes possible, even when the surface of the melt pool is very dirty di to remove contamination during operation.

Overall, the invention is of considerable economic importance, because in all industrialized nations the recovery of the waste that is in the trash valuable non-ferrous metal is gaining in importance. Experiments with optical separation methods have proven the possibility of pre-sorting the mixture in more reliable over this Way to ensure that the inventive melting process is a mixture can be supplied, which is enriched in sufficient moisture with zinc-containing parts is.

The invention shows a new way of doing this to a considerable extent can contribute to the amount of zinc accumulating in metal scrap without a collective melt to be recovered with a later divorce procedure.

The drawing shows a schematic diagram of a device for Implementation of the method according to the invention.

The batch 1 to be melted falls from the charging device 2 in the container 3. This is up to a level 4 with a molten salt 5, preferably made of zinc chloride, filled. The molten salt is heated with burners 6. The temperature monitoring takes place with the thermometers 7. The Zn liquefies in the molten salt 5 and flows through the sieve bottom 8 of the box 9 on the sloping bottom of the container 3 after the lowest point 10 where it collects.

It reaches the collecting vessel via a height-adjustable overflow 11 12. The box 9 is suspended from ropes 13 so that it can swing freely. He will set in oscillation or vibration by a vibrator 15 via the rod 14. The unmelted pieces migrate on the sieve bottom 8 through the opening 16 in the collecting box 17. After the slide 18 is closed, the collecting container be emptied. Recesses 19 are provided on the side walls of the box 9, through which dirt particles can be kept silent on the surface. The parts are removed with the aid of the dirt scraper 20 over an inclined surface and fall into dirt collecting basin 21.

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Claims (7)

Patent claims 1, method and device for separating non-ferrous metal from pre-sorted metal scrap by heating in a liquid medium as a heat carrier with a melting point of the non-ferrous metal to be separated Ternperatur, whereby the mixture of solid metal particles continuously into the liquid Medium is introduced and discharged again, d R d u r c h e k e n n z e i c h -n e t that a salt bath (5) serves as a heat transfer medium, the temperature of which is over 4300, but is below 700 °. 2. The method and apparatus according to claim 1, d a d u r c h g e k It should be noted that the salt bath (5) is a zinc chloride bath. 3. The method and device according to claim 1 and / or 2, d a -d u r c h g e k e n n n n z e i n e t that in a manner known per se the dignified Mixture (1) within the bath (5) exposed to vibrations or a shaking movement will. 4. The method according to one or more of claims 1 to 3, d a d u r c h e k e n n n n e i n e t that the mixture of an ultrasonic irradiation is exposed. 5. The method according to one or more of claims 1 to 4, d a it is indicated that the vibrations are only present in the mixture Area of a limited zone on the way through the bathroom. 6. Apparatus using one of the methods of one or more of claims l to 5, d a d u r c h g e -k e n n æ e i c h n e t that within a bath a per se known sieve-like conveying surface (8) inclined in Börderrichtun is and discharges at its end into a collecting container (17), which via slide (18) or the like. Can be closed. 7. Device according to one or more of the method claims 1 to 5 and / or according to the device of claim 6, d & -d u r c h g e k e n nz e i c h n e t that at the level of the liquid level from outside the Melt bath holder actuatable slide (20) or the like are provided, with which dirt floating on the melt can be removed.