DE2821399A1 - METHOD AND APPARATUS FOR PROCESSING MELT SMARKS - Google Patents

Description

Cromwell Metals, Ine ,, 1895 Sheridan Drive Buffalo, New York 14223 USA

Method and device for processing soot melts.

The invention relates generally to the recovery of the free metal carried away in the scrap obtained from the production of aluminum or aluminum-based alloys.

In the course of conventional aluminum smelting, oxides, nitrides and other non-metallic impurities accumulate the surface of the melted detail. Before parting of the molten metal, these non-metallic substances are removed or wiped off the surface of the melt. Essential Amounts of aluminum metal are inevitably entrained with the non-metallic substances and also with the non-metallic ones Substances removed. This mixture of non-metallic substances, free aluminum and aluminum alloy is called as aluminum-containing smears or scraps. For the sake of simplicity, see this description and the accompanying documents below Claims this mixture of non-metallic substances and

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free aluminum or aluminum alloy as a smear,

As stated above, the smear derived from molten metal containing aluminum inevitably contains a substantial amount of free metal and / or alloy as a result of ordinary agitation of the melt and scraping of the floating material. During the scrubbing or scraping and removal ^, the smear from the upper part of the molten metal, the smear is compressed into pasty, sludge-like masses. These smear masses, when removed from the oven, vary from small lumps, on the order of about 2 to 3 cm and smaller, to large lumps, for example, approaching 30 cm in size. The amount of free metal and / or metal alloy in the smear can vary from 30 wt. # Up to 95 wt the melt is stripped or scraped off. If a batch of hot smear, which is removed from the melt, is left to stand, some free metal collects in the lower part of the mass, but the greater part of the free metal remains intimately mixed with non-metallic components in the form of spheres or small particles and is not to be separated from the non-metallic part. If the hot smear is exposed to the atmosphere, it can also begin to react with the air if the reaction has not started within the furnace; and the reaction is not halted, much of the available metal is lost. Separation of the free metal from the non-metallic part of the smear has been a difficult problem. Some of the methods used and proposed to effect separation are mentioned below.

In one method, the smear is cooled to room temperature as quickly as possible, sieved, crushed, for example in a ball mill, and then sieved again. This mechanical separation measure allows the coarser metal particles

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separated and recovered. However, the mass of free metal in the smear is in the form of small particles, which has been the case so far has made recovery mechanically unattractive.

Another method is to put the hot smear into one Paragraph of molten aluminum or Stirred in aluminum alloy. This method is not effective when stirring in the Smear into the molten metal heel, nearly as much metal is thrown into the smear as is removed from it.

Yet another method is to use the smear after the smear introduced without further preparation in recovery furnaces, which are slagged with salt, for example, and one maintains metal yields. This method is not effective because of the low metal yields, the high energy costs ^ e kg of recovered metal, and because of a serious waste problem of the resulting slag, which because of its Salinity has become "unacceptable to the environment.

Common salt, ie sodium chloride, is used in this process because of the low cost of the material. More expensive salt-type slagging agents or fluxes can be used to increase metal recovery to a limited extent, but then such additional flux costs negate the increased effectiveness. While the cost of sodium chloride ^{1 is} low, so is it the molten metal yield is quite low. These low yields are due to the fact that common salt does not effectively attack the oxide coatings on the small aluminum droplets trapped in the smear. The use of common salt has a further disadvantage in that heat is required as essential to melt the salt, with its melting point at a temperature of about 800 ⁰ G: is. If satisfactory melting is to be made possible, the salt bath must be heated to a temperature which is substantially above its melting point in order to obtain sufficient fluidity, and the bath must be at this temperature

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be held during the introduction of the aluminous smear and during the melting down. For example, where the salt melts at about 800 ⁰ C, the bath to a temperature of the order of 50 ⁰ C would have to be heated up, or in this Pail is at about 850 ⁰ G. Upon melting and treating the permissible aluminum for best results Maximum temperature around 815 ° C. Above this temperature, the quality of the metal deteriorates and undesirable smoke formation occurs. Further, when the aluminum-containing swab salt flux mixture heated to 850 ⁰ G, is, it has a significant resolving power for all metals, which come as impurities into consideration. In addition, the hot melt of common salt strongly attacks the furnace lining.

According to a recently proposed method, hot smear, which can be either the smear as removed from the furnace, or cold smear which has been reheated, was placed in an inclined. brought to a rotary drum furnace which is open to the air, and the abstrioh is rotated therein for a short period of time. If the smear is not already on fire when it is inserted into the drum, ignition is started by adding suitable salts. In this process, a portion of the finely divided free metal is consumed in reacting with the air to create the heat which is essential to raise the temperature of the mass. As a result, the metal yield is not as high as desired. Metal yields on the order of $ 65 to $ 70 of metal present have been achieved by this method, but the average yield has been found to be below $ 60. It is also difficult to control the furnace temperature in this process and in general the temperature is well above 815 ⁰ G with the associated disadvantages "

With reference to all previous methods for the recovery of aluminum metal, it is to be understood that smear, as it is here generally referred to, exists in particles and lumps of material of various sizes. A representative swab sample can after initial conventional milling and preparatory

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Seven the following dimensional ranges, as well as the following aluminum content and recyclable aluminum using the better recovery methods described above:

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approximate metal approximate metal

fo the smear recovery im recovery im

Dimensional,. ^ approximate furnace in $ of furnace in $ enclosed area Deaoaioicung metal content smear of cracked metal

° fj j - 25.4mm + 12.7mm co

- 12.7mm + 6.35mm $ 13 $ 80 $ 56 $ 70 I. 282 - 6.35mm + 2.54mm 15j6 $ 75 $ 38 $ 50 I. 1399 - 2.54mm + 5.08mm $ 25 $ 70 IT / A U / A - 5.08mm $ 25 $ 20 N / A

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The dimensional ranges of - 2.54mm and below would be consumed in the heat of the oven and would be lost if they were be subjected to the heat of the oven. Therefore, these dimensional ranges are generally screened off and found as alumina dust sold with low metal content.

Using a representative swab sample, straining off the dimensional range of - 2.54mm and using the remainder for furnace recovery, the following approximate results are obtained using the methods described above, commonly used aluminum recovery methods:

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Range of dimensions

kg to the oven

kg

Metal content

recovered ne
At aluminum alloy
Metal stanchion bars
$ kg

reclaimed metal

in $ des
Smear

in $ des entrained-; of metal

+ 25 , 4mm 1 2.7mm 9 072 8th 165 $ 90 7th 348 $ 81 $ 90 - 25th , 4mm + 6th , 35mm 10 886 9 253 $ 85 7th 403 $ 68 $ 80 - 12 , 7mm + 2 , 54mm 11 793 9 435 $ 80 6th 604 $ 56 $ 70 - 6, 35mm + 13th 608 10 206 $ 75 5 103 $ 38 5O ₅ ! 45 359 37 059 ⁸²⁵⁸ 26th 458 $ 58 $ 71 • N)
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Using previous methods of metal waste recovery, significant portions of the aluminum or aluminum alloy content in the smaller, low-quality smear particles are therefore lost in the recovery process. This results in a normal metal recovery of about 58% of the smear charge or about 71% of the metal content.

It will also be understood that conventional milling techniques have been used could be used to grind smear for an extended period of time, with the resulting smear increasing Percentage of metal. However, this is not done for at least two reasons. First, it would be remarkable Require amounts of energy to grind the smear for extended periods of time, which is economically impractical. Second, if the smear is milled continuously for an extended period of time, the milling tends to cause a To crush part of the metal into dust which would combine with the oxides, thereby creating such crushed metal could not be used to load an oven.

Therefore, in view of the prior art, it is readily apparent that the present invention represents a major breakthrough in smear processing, such as shown below.

According to the invention, a new and significantly improved method is intended be created to recover a larger part of the swept aluminum from smear, which was previously because of the Difficulties in efficiently processing with lower efficiency occurred. Furthermore, according to the invention, a new and improved smear processing methods can be provided by which low percentage alumina dust of metal for use in various industrial applications. In principle, should fiction according to a method in which selected grade aluminum concentrates are mechanically recovered are made from partially prepared smear concentrates of poor quality. According to the invention, aluminum,

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which is carried away in the smear can be recovered with a high percentage than aluminum bars using conventional ones ovens and the subject matter of the invention. Furthermore, according to the invention Aluminum carried away in the smear can be recovered with lower recovery costs than with the now common ones Methods that require lowering of the quantities Licher deslagging or flux and by maximizing energy and working resources, which results from the Minimizing energy and labor costs per kg of aluminum produced in the furnace and reducing waste problems. Another object of the present invention is to provide a new smear processing method be created through which pellets or pieces of high purity aluminum for use in various industrial Areas of application can be obtained. According to the invention, the amount of waste produced is also intended to be reduced and reduce the air pollution problems created by previous recovery processes whereby the problems of environmental protection are remarkably reduced. According to the invention, lumps should also be metallic Smear material or similar material of irregular size with a predetermined size range, in metallic Pellets or converted into metallic powder, which consists of particles of a predetermined size range.

The invention relates to the recovery of free metal carried away in the scrap that is extracted Melting of aluminum and aluminum-based alloys, whereby the smear is partly after previous preparation procedure is being prepared. The invention is directed to cleaning and manipulating the smear through the more effective Removal of essential parts of the oxide coating on the smear, this leads to the recovery of a remarkably higher proportion of free metal contained in the smear than when using previous cleaning and recovery processes is won. The smear, which is partially processed according to previous methods, is selected in succession mechanical milling and grinding stages guided, with it aluminum oxide dust and aluminum concentrates are separated from each other.

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The aluminum concentrates can be "recovered" using conventional furnace recovery methods can be applied to produce aluminum ingots or they can be further processed through selected stages to produce high quality aluminum pellets.

In summary, raw smear can initially be sifted, ground, and sifted into three fractions and separated, for example as this is known per se. The particles of these fractions can be 6.35mm and larger, 6.35mm down to 2.54mm, and 2.54mm be down in size. This initial preparation and sizing is known per se and is not part of it of the present invention.

Smear concentrates or particles that are larger than, for example 2.5cm, which is $ 20 of a representative sample approaching the partially prepared smear concentrates, high-percentage metallic concentrates of high quality are already up to one Degree that is sufficient for finishing. the Size ranges of the order of magnitude of 2.5 cm and smaller are subdivided according to the method and device according to the invention and processed.

A subdivided size range of poor quality swab concentrate is sieved and conveyed to a first pair of rollers, wherein the rollers have a predetermined distance from one another. The rollers are preferably spring-loaded or otherwise resiliently mounted to allow the rollers to move apart as the swab passes between them. The rollers compress the swab particles or concentrates to a limited degree without substantially removing the particles to crush so that the bonds between the metallic and non-metallic substances in the smear are broken. The swab concentrates so compressed are sieved to remove the limited amount of oxides that result as a result the effect of the roles falling down. The sieved smear in the pressed state is then conveyed to a hammer mill, which loosens and removes the oxides from the aluminum in a highly effective manner because of the previous breakage of the bonds between the meta3JLi ^ cjheji_substances and the

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Oxides through the rollers. The oxides are then sieved out and aluminum concentrates result, which from Oxides are significantly free. These resulting concentrates can be added to a recovery furnace or to a second Pair of rollers are conveyed. The second pair of rollers essentially crushes the high quality aluminum concentrates into flattened ones High quality aluminum scales. A small percentage of the oxide material is removed by the action of the second rollers.

At this point the aluminum scales are further processed as follows:

(1) The scales can be fed into an oven for recovery of the contained metal as aluminum ingots, the recovery ratios being roughly the same as for partially prepared Smear concentrates larger than one inch.

(2) The aluminum scales can be milled by a series of hammer mills machined to make the scales in aluminum pellets of high purity, for example of the order of 2.54mm and smaller to convert. The larger fragments tend to aggregate into pellets of essentially pure aluminum. The smaller fragments also tend to aggregate into aluminum pellets, but with fewer ones Purity because they are mixed with tiny bits of oxide that the process does not remove.

(3) The essentially pure aluminum pellets can be placed in a furnace to recover the metal content than aluminum bars with recovery rates that are better than the recovery rates of partially prepared ones Swab concentrates larger than an inch in size referred to above.

The present invention also describes an apparatus for comminuting a metallic substance such as aluminum concentrates high quality or scrap metal particles. The device includes a mill with a number of cutting

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knives with leading edges which are shaped so that metallic Substances are cut through or shredded.

The foregoing and other objects, advantages and characteristic features of the invention will appear more clearly from the following detailed description and illustrative embodiment in conjunction with the accompanying drawings, in which like reference numerals indicate corresponding parts in the different figures.

1A and 1B schematically show an embodiment of a Apparatus as used to carry out the invention for the recovery of aluminum metal from smear, the Smear is fed to a conveyor on the left-hand side of FIG. 1A and the products obtained on the right-hand side from Fig. 1B;

Figs. 2A and 2B show a smear lumps, which was prepared according to previous methods previously ground and brought to a size of about 6.35 to 19 »Ø5mm and which Gew.?S about 65 and 75 wt. ° / o aluminum metal in combination with Non-aluminum materials such as ferrous substances and oxide substances j

Figures 3A and 3B are views corresponding to Figures 2A and 2B of the swab after it has passed through the first pair Rolling, whereby the bonds between the metal and the oxides are substantially broken;

4A and 4B show corresponding aluminum concentrates and non-aluminum dust substances separated therefrom, after the smear passed through the first pair of rollers and the associated hammer mill is;

Figure 5 illustrates aluminum concentrates after passing through the second pair of rollers, the concentrates essentially have been flattened;

Fig. 6 shows aluminum particles after they have been through the

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the hammer mill following pairs of rollers have passed, the concentrates have been further purified;

Pig. Figure 7 is an illustration of the cutting edge of a knife in conjunction with that of the Pig. 8 and 9 illustrated Mill;

Pig. Figure 8 is a side view of a mill, with portions thereof shown in section, for converting lumps of aluminum into Aluminum pellets with particles of a predetermined size range; and

Pig. Figure 9 is a transverse view in section on line 9-9 of Figure 8; which shows the hammer mill illustrated here.

Looking at a detailed description of an implementation ^ form of the method which includes the present invention in part and an embodiment of the methods in connection therewith standing device is to be understood that the spruce aluminum, Oxide dust in combination with varying degrees of aluminum dust, which is obtained from the smear has a significant market value, for example in the exothermic industry, as it relates to the manufacture of steel. The aluminum dust that is carried away in the spruce aluminum substances is subject to oxidation and is accordingly a source of considerable heat generated in steel making what is required is what is known to the person skilled in the art. As the energy becomes more expensive in general, it becomes in it is even more desirable for the steel industry to improve the quality of the steel produced with a view to avoiding it reworking steel products, which can be costly in terms of energy. This only represents one of the users for the aluminum / oxide dust caused by the present Invention is created and illustrates its importance in relation to current and potential future energy problems. Of course, the value of recovering aluminum concentrates from the smear is in selective degrees of purity readily apparent to those skilled in the art by a mechanical process.

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Smear, as such, which here aluminum, aluminum alloys and other similar metals can be obtained from a metal manufacturer through a smear processor, wherein the smear has particles or lumps of very small size, up to lumps, their size for example is on the order of about 50cm · For example, a 45360kg load of raw aluminum swab can be on the order of Containing from 75 to 80% by weight of metallic aluminum, combined with non-aluminum substances · The relatively larger lumps of the smear generally contain higher weight percentages of aluminum metal than the smaller lumps and For the purposes of the description, aluminum should be understood here to mean both pure aluminum and aluminum alloy will. Smear lumps of the order of 5 cm and larger can therefore be processed for metal recovery are made using previously known procedures and the invention is of lesser concern with abstrial lumps of this size than those of the order of 5 cm and smaller. In other words, the relatively smaller one Amount of oxide, on the larger swab lumps with higher metal content * creates a minor problem in the recovery of metal from this · However, as discussed and further discussed, it becomes progressive with the decrease in the size of the smear lump more difficult to process in an oven for recovery. The smaller the smear lump gets, it has a relatively larger surface area. The relatively larger surface area subjects the smaller concentrates to this Degradation in the heat of the; Furnace. The smaller the smear lump the more its relatively non-metallic oxide coating increases the carry-over of a relatively smaller percentage Metal within the concentrate. In this regard, the oxides have an insulating effect on the entrained aluminum and salt flux are less effective in attacking the oxide coatings and consequently less entrained metal is released. Also because of their lower diohte, a good part of the metal released from the smaller smear is now subject to it clump burning in the heat of the stove. As stated above

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are, accordingly, previous methods for recovering Metal from smear lumps, especially in the size range of 5cm and smaller, not effective, for example on the order of magnitude 90% of the metal carried over with dimensions in the Approximately 5cm, if processed correctly, can be recovered to less than half of the amount that is carried over Metals with dimensions close to 2.54mm. Therefore, the method to be described is particularly applicable to aluminum scrap lumps or particles of smaller size, although it is also generally applicable to metallic smears.

In Pig. 1A is a smear that was previously ground and from the total smear has been screened off in particle sizes in the range of, for example, 2.54 mm to 6.35 mm, brought into the funnel 10 and conveyed upward to a two-day screen 14 by means of a cup conveyor 12. It is to be understood that the present Method is more effective when the smear that is placed in the funnel is appropriate in selected size ranges has been divided. With regard to the swab particles of a dimension of 5 cm and smaller, the size ranges from smear to hopper loading include: 0.635mm to 1.27mm, 1.27mm to 2.54mm, 2.54mm to 6.35mm, 6.35mm to 12.7mm, 12.7mm to 25.4mm, 25.4mm to 38.1mm and 38.1mm to 50.8mm. Of course, these ranges can be varied. As in the Pig. 2A and 2B, comprises a typical swab particle or clumps, particles 20 and other foreign substances 23.

Figures 2B, 3B and 4B illustrate the higher percentage of metal in the larger Abstriohpartikel compared to the Pig. 2A, 3A and 4A. For example, Pig. 2A one Metal content on the order of $ 65 for a 6.35mm particle pose while Pig. Figure 2B may represent a metal content on the order of $ 75 for a 19.05mm particle.

Oxide and aluminum dust with particle sizes of less than, for example, 1.27mm, go down through the two-tier sieve 14 through into the funnel 22 and are used as the end product

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collected for purposes as set out above. As for the separation of non-metallic substances from metallic substance / Concentrate is concerned, it is to be understood that tiny metal particles, essentially in the form of dust, with which non-metallic substances are mixed, which are also tiny Own particle size. Necessarily, the dust collected in hopper 22 has a varying percentage of aluminum dust mixed with it. The container 22a can simply be a removable barrel for receiving the alumina dust from the Funnel 22. The swab material which does not fall through the two-tier sieve 14 passes over a magnetic one Separator 24, which removes loose ferrous substances such as 16, after which the swab is conveyed to funnel 26 will. The swab in funnel 26 is in turn directed onto a conveyor 28 which feeds the swab a shaker feeder 30 which conveys the swab material to a first pair of spaced apart rollers feeds.

The rollers 32 are preferably resiliently mounted with respect to one another, for example by means of springs 33. The rollers 32 have a predetermined distance less than the selected size range of the swab particles passing therethrough, whereby the rollers 32 can be resiliently separated from one another as the smear is passed. For smear of 2.54mm to 6.35mm, which is fed to the rollers 32, the roller spacing could be in the order of magnitude of, for example 1.27mm! lie. The spacing would be the same for other swab size ranges increased or decreased so that the distance is less than the smallest size that passes through Particles. The rollers 32 are adjusted to compress the swab passing therethrough to a limited degree, without essentially crushing the smear, so that the bonds between the metallic and non-metallic Substances are essentially broken down. The spring pressure of the rollers, which is set independently of the distance should be increased or decreased by the above for the larger or smaller particle sizes

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To exert an effect on the smear.

The heated pressure exerted by the rollers 32 can be recognized from a comparison of FIGS. 2 and 3 # which smear on the input side or »the output side of the Represent roles 32. As illustrated in Fig. 3, the breaking of the bonds between the metallic and non-metallic Substances can be represented in a schematic sense by the break lines 21. Of course there are also oxide bonds broken open on the surface of the aluminum particles. The limited one Pressure that is exerted by the rollers 32: is in contrast to previous roller breakers, which for good Part of the continuous smear is pulverized or crushed. The oxide substances, such as 18, are converted into metallic ones Ground substances so that they are not easily separated from it during subsequent grinding, as is the case with the oxides Case is which are subject to the limited pressure of the present method. In this regard, the springs 32 act so that Avoid applying excessive pressure to the smear passing through the rollers. However, it is within the framework the invention that the rollers 32 can be fixedly mounted with respect to one another and are therefore not resiliently separable. With this arrangement, the oversize of the smear that goes through the rollers would be limited to a narrower area, to ensure that only an adequate amount of pressure and shock is applied to the smear.

The crushed smear flows from the rollers 32 up an inclined conveyor 34 to the hopper 36 * which feeds a cup conveyor38. The Beehertransporter 38 gives the smear on a one-level shaker screen 40 which removes non-aluminum and aluminum dusts in a manner sifts, which is similar to the collection of such substances in the funnel 22 described above. which do not fall through sieve 40 into funnel 42 and container 42a below go to a hammer mill 44 (Figure 1B). The hammer mill 44 of a type known per se pushes the smear, which was previously broken up to a limited extent,

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so that loose oxide materials are knocked off. In this regard, the previous pressing of the smear through the Bollen 32 meaningful so that the mill 44 is able to strip the oxides from the metal after the rollers 32 die Have broken ties between them. However, the hammer mill 44 does not necessarily deform the aluminum particles and clumps, as can be seen in Figure 4, but yields smear particles with a significantly higher percentage of metal (concentrates), with oxides actually from quite a few surface areas of the metal are completely removed.

An air separator or separator 45 is in fluid communication with the lower housing of the mill 44 and pulls out a certain amount of non-metallic and metallic dust the housing, for example to a remote bearing housing.

The smear processed by the hammer mill 44 (Fig. 4) » • falls on the underlying conveyor 46, which is the smear to the funnel 48 and the associated cup conveyor 50. The cup conveyor 50 is transported the lumps of aluminum concentrates and split off oxide materials which were not removed by the air separator 45, upward onto a one-tier shaker 52. The resulting relatively high metal concentrates can be over Another (not shown) magnetic separator go on a shaker feeder 54. The ground non-metallic Substances as well as tiny aluminum particles which may be present fall through the sieve 52 as the end product funnel 56 in a manner similar to that described with reference to screens 40 and 14. In practice it was found that the limited pressure exerted by rollers 32 is on the order of about 7 to 8 $ that originally present oxides are removed and in the further grinding stage, such as at 44, a significant additional Amount of non-metallic substances (oxides) on the order of $ 11 to $ 12 of the original non-metallic substances removed.

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The smear or the aluminum concentrates, which are added to the shaker feeder 54 are a marketable product without the need for further processing according to the present invention Invention. Further processing, which is within the scope of the invention, increases the purity of the concentrates, but of course with costs for further processing. The concentrates that are created at the feeder 54 are from Oxides have been purified to such a degree that they can, for example, be placed in a residue furnace for the recovery of metal in ingot form, as is known per se. That Loading a residue oven with relatively pure concentrates as provided by the present invention is in contrast to previous methods of charging rotary kilns with considerably less pure concentrates for the extraction of metal, which includes all the disadvantages, which is referred to above.

Instead of being removed as the end product, however, the concentrates on the feeder 54 can also be at a distance from one another located rollers 58 go, which deform the aluminum concentrates into flattened, scale-like pieces, as shown in 5 are illustrated.

The rollers 58 preferably include stationary attachments, whereby the concentrates from the feeder 54 are compressed into flakes are illustrated as in Fig. 5, wherein the flakes can be on the order of, for example, 1.59 m thick with respect to a swab of 2.54mm to 6.35mm coming from the funnel 10. The distance between the rollers 58 is on one corresponding degree and can be increased or decreased, depending on the larger or smaller sizes of the the smear originating from the funnel 10. The scales stand out the sieve 59 underneath, which some additional aluminum and oxide dust in the funnel 61 and in connection with it can pass standing container 61a.

At this point the scales have a slightly higher percentage of metal than the concentrates which are the feeder

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54 are promoted. In accordance with one embodiment of the invention, the scales resting on the sieve 59 can withdrawn as a marketable product without the need for further processing. Regarding the conversion in bar form, the flakes may be considered more desirable than the concentrates conveyed to conveyor 54 because the scales, for example, have a higher density and consequently more quickly below the surface of a residue oven sink, of course it is important that the Batch to the residue oven (concentrates / pellets) sinks below the oven surface, so that a possible burn on the Atmosphere is avoided.

Should it be desired to convert the scales on the sieve 59 into an even purer form, the scales can be removed from the sieve 59 are conveyed to a hammer mill 60, an embodiment of which forms part of the invention and shown in Figs 7 through 9 is illustrated.

The scales of FIG. 5 are processed by the mill 60 and flow through the passage 80 into an air separator 81 from Cyclone type. The cyclone 81 is a known device in which the milled scales under a tangential Enter angles into the cyclone so that a low pressure area is created in the central part of the cyclone. The low one Pressure pulls aluminum and oxide dust into the central part, from where it in turn passes through line 83 to a distant one Bearing housing 92 goes. The bearing housing 92 empties in an underlying removable container 92a which is similar to containers 61a, 56a, and so on. The Schwerera.iL Metal particles in the cyclone separator 81 fall onto a second mill 78 below the cyclone 81. The output from the mill 78 is conveyed through passage 84 to a second cyclone 85 which is similar to cyclone 81 in all respects and which carries aluminum and oxide dust to line 83 and bearing housing 92.

Metallic concentrates, which are in the form of pellets

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can, as shown in Fig. 6, fall from the cyclone 85 onto the sieve 88 below Sieve 88 fall have a higher purity than the flakes according to FIG. 5, which are fed to the mill 60, namely because of the oxides removed by the cyclones 81 and 85, and also because of the oxide and aluminum dust, which by the Sieve 88 goes to the funnel 96 below and to the container 96a. The pellets which remain on the sieve 88 will be in turn conveyed to the hopper 98 and the container 98a located below as the end product.

The pellets or concentrates that are collected in the container 98a are the most desirable of the various products that which are produced according to the invention because they have the relatively greatest purity. Of course they require Pellets in the container 98a more processing than the other concentrates created according to the invention, which because of their degree of processing have lower purity. Accordingly, the user of this invention will be able to use metallic concentrates selectively process up to different degrees of purity, depending on processing costs, market conditions, etc.

The mills 60 and 78 can be conventional mills with generally blunt blades which are used to form bead-like pellets as illustrated in FIG are.

In addition, mills 60 and 78 can be of such type as they is described below and forms part of this invention, resulting in concentrates collected in hopper 98 of shredded, scale-like shape leads.

The hammer mill 60 in fig. 8 and 9 includes a housing 62 and a rotatable hub 64 adapted for rotation within the Housing is mounted on the shaft 66. The shaft 66 can be driven in a clockwise direction, for example by an electric motor as shown in FIG. A number of cutting blades 68 are hinged around the circumference of the hub 64 attached by fasteners 70.

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7 illustrates a transverse view of a cutting knife 68, the knife having a chipping blade shape along both of its widthwise edges. In this regard, the Cutting knife interchangeable leading and trailing edges, which can be used to extend the life of the cutting knife to lengthen, as will be described in more detail below. In addition, the cutting blades 68 have mounting holes 72 at both ends by using the mounting holes 72 each end of a cutting knife can be replaceably attached to the hub 64 so that the useful life of the Cutting knife can be expanded. In addition, an opening 74 is provided in the upper part of the housing 60 through which aluminum concentrates fed to the mill. In addition, a substantial amount of air is drawn into the mill through opening 74 drawn. The lower part of the housing 62 has a number of openings 76 of predetermined dimensions, which act as a sieve function to ensure that the aluminum material is chipped or ground to a certain size before it goes to the subsequent mill 78 (Fig. 1B).

The mill 78 is functionally equivalent to the mill 60. The size of their openings 76 can be smaller than that in FIG Mill 60 so that the aluminum concentrates or chips are further reduced in size. The one ground by the mill 60 Product (Pig. 1B and 8) goes through openings 76 in the base of the housing 60 and further into a tubular passage 80 which communicates with the cyclone 81. The mill 60 tends to draw a substantial amount of outside air through the opening 74, which in turn results in an air flow through the base of the housing of the mill 60 and through the passage 80 to the cyclone 81, so that for the ground Aluminum creates a driving force. The cyclone 81 supplies the aluminum in the process to the mill 78, which in turn, the further processed aluminum leads to passage 84. The second mill 78 provides another stream of air through the Cyclones and passage 84.

In summary, it should be understood that metallic concentrates 135/1 809847/0957

different degrees of purity by the above method and the protruding gate direction selectively smeared. which the latter has so far had a significantly lower value, for example with regard to the recovery of aluminum metal. The admixed Qtxyd and aluminum dust, which are collected at different points in the present process, although they are different percentages Contain aluminum dust, quite marketable, such as in the manufacture of steel

The combination of the procedural steps, which by the first Roller pair 32 and the mill 4 are created, are fundamental in the present method for the soaking of the metallic Concentrates in progressively greater degrees of purity selected stages. As noted, it is preferred that the rollers 32 be spring loaded to facilitate it on Limited pressure was applied to the swab passing therethrough for the reasons set out above. The following, through the mill 44 completed grinding, again completing the limited pressure exerted by the rollers 32, around the abstriel to clean effectively to a significant degree. As described, the concentrates are deposited on the sieve 52 after the grinder 44 are available, a valuable product which, for example. directly into a furnace for metal recovery in ingot form can be given, of course, the concentrates on the Sieve 52 can be further cleaned to a higher degree of purity by being processed further by the rollers 58. Again, the shell-like particles which go from rollers 58 to screen 59 can be considered an end product of the present Process can be viewed, or the flakes on the sieve 59 can be subjected to further grinding and separation stages, in order to produce concentrates or pellets of an even higher purity.

It is also within the scope of the invention that metallic scrap material such as aluminum turnings, can be fed directly to the rollers 58 for conversion into aluminum chips, by going through the in the pig. 7 to 9 described

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Cave to be edited · In this regard, the in the FIGS. 7 to 9 describe hammer mills in their mode of operation unique in terms of cutting knives 68 which tend to cut the metallic material being processed in the mill to cut through.

From the foregoing it can be seen that the objectives of the present Invention have been fully achieved · As a result of the invention, there has been a vastly improved method for Recovery of metallic substances created from smear material Furthermore, the method can be used to break irregularly sized lumps of metallic scrap into ground To convert shavings similar to chips. IKLe method is mechanical in nature and can be used on a production basis also became a novel and unique Mill designed for converting lumps of aluminum or compressed flakes into aluminum chips Dimension.

The invention is not limited to those reproduced here by way of example Embodiments turned off alone. Rather, various modifications are within the scope of the invention for the person skilled in the art given without further ado

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Claims (47)

"28-399 Claims Ι.) Method of recovering entrained in smear metallic substances, in 3? orm relatively highly metallic concentrates, characterized in that the swab is conveyed to a pair of rollers, the rollers being a predetermined distance apart each other and the smear comprises particles of a predetermined range of dimensions; that one. smear to a limited extent, without essentially crushing it, between the pair of rollers by pressing the. Smear between the pair of rollers can pass through, so that the bonds between the metallic and non-metallic substances in the smear are essentially broken up; that one grinds the smear after its passage through the pair of rollers, so that metallic and non-metallic substances are split off from one another; and that the non-metallic substances are separated from the metallic ones Separates substances, so that relatively highly metallic concentrates remain. 2.) The method according to claim 1, characterized in that the metallic substances consist of or contain aluminum. 3.) Method according to claim 2, characterized in that the Pair of rollers is resiliently mounted in relation to each other and has a predetermined distance which is less than that before A certain range of dimensions of the smear particles, which makes the rollers resilient when the smear passes between them can separate from each other. 4 ·)) Method according to claim 3 »characterized in that one separating the non-metallic substances from the metallic substances by passing both substances over a sieve leaves. 5.) The method according to claim 3 »characterized in that one Particles that are smaller than a predetermined size and that are mixed into the smear are removed prior to ^155/1 809847/0967 2821199 Let smear pass between the pair of rollers. 6.) The method according to claim 3, characterized in that substances with magnetic properties which are in the smear are mixed in, removed from the smear before the smear is allowed to pass through the pair of rollers, r'.by one lets the smear go over a magnetic separator. 7.) The method according to claim 3 »characterized in that the smear, which is conveyed to the pair of rollers, consists of particles exists, which are larger than 1.27mm, but less than 2.54-mm in their largest dimension. 8.) The method according to claim 3 »characterized in that the smear, which is conveyed to the pair of rollers, consists of particles exists, which are larger than 2.54mm, but less than 6.35mm in their largest dimension. 9.) The method according to claim 3, characterized in that the smear, which is conveyed to the pair of rollers, consists of particles exists, which are larger than 6.35mm, but less than 12.7mm in their largest dimension. 10.) The method according to claim 3 »characterized in that the smear, which is conveyed to the pair of rollers, consists of particles exists, which are larger than 12.7mm, but less than 25.4mm in their largest dimension. 11.) The method according to claim 3, characterized in that the Smear, which is conveyed to the roller pair, consists of particles which are larger than 25.4mm, but smaller are 38.1mm in their largest dimension. 12.) The method according to claim 3, characterized in that the smear, which is conveyed to the pair of rollers, consists of particles exists, which are larger than 38.1mm, but less than 50.8mm in their largest dimension. 13.) The method according to claim 1, characterized in that the pair of rollers is resiliently mounted with respect to each other and the Rolls have a predetermined distance, which is less 809847/0967 is than the predetermined size range of the smear particles, whereby the roles can resiliently separate from each other when the smear passes between them. 14.) The method according to claim 1, characterized in that the Pair of rollers is essentially rigidly mounted and the rollers have a fixed, predetermined space between them, where the roller spacing is less than the predetermined size range of the swab particles 15.) The method according to claim 14, characterized in that the metallic substances made of aluminum exist respectively. Contains aluminum. 16.); The method of claim 1, further characterized by conveying the relatively highly metallic concentrates to a second pair of rollers which are a predetermined distance apart possess, and that one compresses the metallic concentrates between the second pair of rollers by the Lets concentrates pass between them to form relatively thin, scale-like bodies from these metallic concentrates. 17.) The method according to claim 16, characterized in that the metallic concentrates consist of aluminum or contain aluminum. 18.) The method of claim 17, further characterized in that that one pushes the scale-like bodies through a number of grinding surfaces so that the metallic concentrates and non-metallic substances split from one another, and that one removes the non-metallic substances from the metallic concentrates separates, so that the latter remain as relatively higher metallic concentrates. 19 ·) Method according to claim 18, characterized in that the grinding surfaces have knife-like surfaces. 20.) The method according to claim 18, characterized in that the relatively higher metallic concentrates and the non-metallic Substances can be separated from each other by making them ■ 8098 k 7/09 57 can pass through an air separator. 21.) Method naoh claim 3, characterized in that the Smear, which is conveyed to the roller pair, consists of particles which are larger than 0.635 mm, but smaller are as 1.27mm in their largest dimension. 22.) Method naoh claim 17, characterized in that the first pair of rollers is resiliently mounted with respect to each other and there is a predetermined distance between the rollers which is less than the predetermined size range of the Abstriohpartikel, causing this first pair of roles in the Durohgang the smear between them, sioh resiliently separate from each other. 23) The method according to claim 22, further characterized by that the scale-like bodies are held or pushed by means of a number of grinding surfaces, so that the metallic ones Concentrates and the non-metallic substances split from one another, and that the non-metallic substances of separates the metallic concentrates, so that the latter remain as relatively higher metallic concentrates. 24.) The method according to claim 23, characterized in that the grinding surfaces have knife-like surfaces. 25.) Method naoh claim 23, characterized in that The non-metallic substances can be separated from the metallic concentrates by passing both over a sieve leaves. 26.) Method naoh claim 23, characterized in that the relatively higher metallic concentrates and the non-metallic Substances are separated from one another by letting them go through an air separator. 27.) Method according to claim 22, characterized in that the smear, which is conveyed to the first pair of rollers, consists of particles which are larger than 0.635mm, jjedooh are less than 1.27mm in their largest dimension. ⁿ 155/1 809847/0957 "~". "" "~ 282ί399 28.) The method according to claim 22, characterized in that the smear, which is conveyed to the first pair of rollers, consists of particles which are larger than 1.27mm, but smaller than 2.54mm in their largest dimension. 29 ·) Method according to claim 22, characterized in that the smear which is conveyed to the first pair of rollers consists of particles which are larger than 2.54mm, but smaller than 6.35mm in their largest dimension, 30.) The method according to claim 22, characterized in that the Abstrioh, which is conveyed to the first pair of rollers, consists of particles which are larger than 6.35mm, but smaller than 12.7mm in their largest dimension. 31.) The method according to claim 22, characterized in that the smear, which is conveyed to the first pair of rollers, consists of particles larger than 12.7mm, however less than 25 »4mm in their largest dimension. 32.) The method according to claim 22, characterized in that the smear, which is conveyed to the first pair of rollers, consists of particles which are larger than 25.4mm, but smaller than 38.1mm in their largest dimension. 33 ·) Method according to claim 22, characterized in that the smear which is conveyed to the first pair of rollers consists of particles which are larger than 38.1mm, but smaller than 50.8mm in their largest dimension. 34.) Method according to one of the preceding claims for Converting clumps of metallic matter having irregular dimensions and a predetermined range of dimensions into metallic ones Concentrates of a predetermined size range, characterized in that the lumps of metallic substance conveyed to a pair of rollers spaced a predetermined distance apart; that you get the clumps of metallic matter between the pair of rolls by letting the lumps pass between them to form relatively thin, scale-like bodies from the lump; and that one 809847/0957 2821393 converts so-like bodies into metallic concentrates, by cutting the scale-like body with a knife-like one Surface hits or pushes around the shell-like bodies to cut or chipped metallic particles to shred. 35.) The method according to claim 34 »characterized in that the metallic substance which passes through the pair of rollers, successively by a number of knife-like Surfaces is beaten and passed accordingly over a sieve is used to separate chipped metallic particles of a predetermined size or smaller. 36.) Method according to claim 34 »characterized in that the metallic substance consists of aluminum or aluminum contains. 37.) Method according to claim 36, characterized in that the non-metallic substances are removed from the metal particles splits off, whereby the metallic particles and the non-metallic substances are split from each other by lets this go through an air separator. 38.) Method according to claim 36, characterized in that aluminum dust-like substances are used during the strike or pushing is split off from the aluminum-metallic particles by means of the knife-like surface, whereby the aluminum removes dew-like substances in a stream of air. 39 ·) Device for carrying out the method according to one of claims 1 to 38 and 43 to 48 with a mill for comminuting a metallic substance into metallic particles of a predetermined size range, the mill being the following Features include: a housing; a rotating hub arranged for rotation within the housing; one Number of sons oath knives, which are arranged around the circumference of the hub and terminate in the vicinity of the housing, the knives being hingedly connected to the hub and leading edges or have leading edges which are shaped to carve through the metallic substance; and the • ^135/1 809847/0857 housing has a feed device for feeding the metallic Substance to the knives, as well as a sieve device through which the metallic substance passes after their conversion into metallic particles by the working of the knives. 40.) Device according to claim 39 »characterized in that the knives can be attached to the hub at each of their ends. 4-1.) Device according to claim 39 »characterized in that the knives have front and rear edges which> can be reversed with respect to each other so that the useful life of each knife is extended. 42.) Device according to one of claims 39 to 41, characterized in that the knives at each of their ends to the hub can be affiliated. 43.) Method according to claim 4, characterized in that one removes the non-metallic substances from the metallic substances through the additional step of seeing the same separated by an air separator 44 ·) Method according to claim 4, characterized in that aluminum dust-like particles are split off from the metallic substances in such a way that they come with the non-metallic substances remain mixed after the latter are separated from the concentrates. 45.) The method according to claim 20, characterized in that aluminum dust-like particles of the metallic substances split off so that they remain mixed with the non-metallic substances after the latter from the concentrates are separated. 46.) The method according to claim 25, characterized in that the aluminum dust-like particles from the metallic substances are split off so that they are with the non-metallic substances after separating the latter from the concentrates remain mixed. τ 135/1 809847/0957 47.) Method according to claim 26, characterized in that aluminum dust-like particles from the metallic substances be split off in such a way that they are with the non-metallic Substances after separating the latter from the concentrates remain mixed. 4-8.) Method according to claim 43, characterized in that aluminiumstaubähnliohe particles are split off from the metallic substances so that they are with the non-metallic substances remain mixed after they have been separated from the concentrates. 809847/0957