HU181419B - Process and apparatus for separating metal-content of slags in concentrated form - Google Patents

Description

Process and equipment for the recovery of metallic slag in a concentrated form

BACKGROUND OF THE INVENTION The present invention relates to a process and apparatus for recovering metal content in metallurgical slags in a concentrated form, in particular for the production of aluminum or aluminum alloys.

It is known that during melting of aluminum oxides, nitrides and other non-metallic impurities accumulate on the surface of the melt. Non-metallic impurities are usually removed from the surface of the molten metal prior to dripping. During removal, aluminum melt will inevitably be removed along with non-metallic impurities. A slag blend consisting of non-metallic materials, aluminum and an aluminum alloy is commonly referred to collectively as an aluminum slag. For the sake of simplicity, this mixture will hereinafter be referred to as slag.

As mentioned above, the slag removed from the surface of the molten metal will inevitably contain pure metal and / or alloys as a result of mixing the molten metal and removing the slag. During the removal of the slag on the surface of the molten metal, the material removed is a slightly compacted, paste-like mass. After removal from the furnace, this mass contains pieces of any size from relatively large lumps to small particles. They range in size from 25 mm to 30 cm. The amount of pure metal or alloy in the slag can vary from 30% to 95%. The actual composition depends on a number of factors, such as the composition of the molten alloy, the melting technology, and the diligence involved in removing the slag. If the slag removed from the melt is allowed to stand for a while, pure metal will accumulate at the bottom, but a significant amount of the pure metal will bind to the non-metallic elements in the form of particles or larger pieces. In addition, relatively high temperature slag reacts with oxygen in the air when it has not already begun in the furnace. If this process is not stopped, much of the metal in the slag will be lost.

Extraction of the metal content of various slags has long been a problem in metallurgy. Solving it is not an easy task, although many procedures and solutions have been tried over time.

According to one known method, the slag is cooled to room temperature as quickly as possible, screened and milled in a ball mill and passed through a sieve again. With this mechanical technology, coarse metal particles in the slag can be easily selected and recovered. However, pure metal in the slag present in the form of small particles cannot be recovered by this process.

In another known process, the slag is mixed by adding molten aluminum or aluminum alloy in a vessel. However, this is not effective enough, because essentially as much pure metal as is removed from the slag binds during mixing.

They also employ a process in which the slag is removed without any preparation to a slag treatment furnace and a fluid such as salt is added to recover the metal in the slag. However, this process is not efficient enough as the recovery efficiency is low enough, the weight of recovered metal per unit weight is relatively high and presents a problem

-1181419 also uses residual slag because of its high salinity it is harmful to the environment.

Most of these processes use common salts, i.e. sodium chloride, to reduce the cost of the process. However, other types of flow salt are also used to increase the efficiency of metal recovery. In this case, however, it is precisely the cost of the salt types used that offsets the increase in extraction efficiency. Indeed, the efficiency of treatment with salt is extremely low. The reason for this is that the salt does not react effectively enough with the oxide coating on the clean aluminum surface bonded to the slag. A further disadvantage of using sodium chloride is that it requires a significant amount of heat to melt, since it has a melting point of approx. 800 ° C. If the salt is to be properly melted, it must be heated well above this temperature in order to achieve adequate fluidity. This state of the salt must be maintained throughout its introduction into and treatment with the furnace. Thus, if the salt used has a melting point of 800 ° C, the dose should be heated to at least 850 ° C. At the same time, the optimum temperature for melting and handling the aluminum 20 is approx. 816 ° C. Above this temperature, the quality of the metal deteriorates and undesirable flue gases are produced.

In addition, heating the slag salt mixture to 850 ° C will very strongly dissolve all the metals present in the slag, which are contaminated with aluminum. The disadvantage of using salt in the oven is that it is very heavily stressed in the furnace lining.

In another embodiment, the slag 30, which has been separated from the molten metal, or is already cooled and reheated, is placed in a tilting shaft rotary drum and rotated therein for a short period of time under the influence of air. If the dross inserted in the drum is not yet burning, flux is added to the drum for ignition. In this solution, finely dispersed metal particles in the slag react with air and provide sufficient heat to heat the entire mass during combustion. However, this also means that the efficiency of metal extraction cannot be high enough. The recovery obtained by the process can be optimally 65-70%, but in most cases it is below 60%. In addition, it is difficult to control the furnace temperature during the process, so that the temperature 5 is generally higher than 816 ° C, which has the disadvantages mentioned above.

As described above, the slag treated in the processes described generally consists of particles of varying sizes, oversized. The size composition of the portions of a typical aluminum mold after conventional pre-milling and sieving, the aluminum content of the slag, and the amount of aluminum that can be recovered by the methods described are described below. These data are summarized in Table 1.

Table 1

size range Slag- quantity Approximate metal content Approximate metal extraction relative to slag volume Hozzávető- metal extraction relative to the amount of metal in the slag 25 mm io% 90% 81% 90% 25mm - 15mm 12% 85% 68% 80% 13mm - 7mm 13% 80% 56% 70% 7mm - 2.5mm 15% 75% 38% 50% 2.5mm to 0.5mm 25% 70% - - 0.5 mm 25% 20% - -

Generally, particles smaller than 2.5 mm are burnt at the furnace temperature during treatment. Therefore, these particles are mostly screened out and sold as low alumina powder.

After screening of particles smaller than 2.5 mm, the results described in Table 2 can be obtained by the procedures described. Table 2 is based on the operating balance of the slag treatment furnace.

Table 2

size range Dose [Pound] color Metal The amount [Pound] metal Content [%] Quantity of spikes produced [pound] Metal extraction relative to slag volume to Extraction of metal relative to the amount fed 25 mm 20,000 18,000 90% 16.200 81% 90% 25mm - 13mm 24,000 20,400 85% 16.320 68% 80% 13mm to 7mm 26,000 20.800 80% 14.560 56% 70% 7mm - 2.5mm 30,000 22,500 75% 11,250 38% 50% 7mm - 2.5mm 30,000 22,500 75% 11,250 38% 50% 100,000 81.700 82% 58.330 58% 71%

From the foregoing it can be seen that small slags of aluminum or aluminum alloy are not recovered during slag treatment by known methods and are wasted during treatment. Therefore, only about 58% of the slag to be regenerated, and the metal contained in the slag to about 60%. 71% can be recovered. 60

A further disadvantage of the known solutions is that it takes quite a long time during the preparation, when grinding the slag, to increase the relative metal concentration of the slag. However, slag mining for a long time is not possible for several reasons. First, 65 long-term grinding is extremely energy-intensive and therefore uneconomical. On the other hand, if the slag is chopped continuously over a long period of time, some of the metal contained therein will precipitate in powder form and mix with the oxides, which means that it cannot be used in a regeneration furnace.

It is an object of the present invention to provide a process and apparatus which makes it possible to overcome the drawbacks described, to increase the efficiency of the process and to make the production of non-ferrous slag cheaper at higher rates.

The object of the present invention is to provide a method according to the invention

-2181419, during slag treatment, pass slags of a specified size range between rolls adjusted to the size range, and then press the slag pieces between the rolls without breaking so as to separate the metal and non-metallic part boundaries and then break finally, the metallic and non-metallic parts are separated.

The process of the present invention also provides for the regeneration of relatively low metal-containing alumina powder, whereby various aluminum-containing fractions can be separated from the slag.

The process provides extremely high yields and can be processed in the form of aluminum ingots obtained from the aluminum form.

It is also possible to process the aluminum-containing slag in the process of the invention by using the recovered aluminum in the form of pellets.

The process according to the invention can significantly reduce the amount of wasted material and at the same time, of course, reduce the amount of air pollution compared to conventional processes.

In the process, various irregularly sized slag pieces are minced to a certain size and processed in this way.

The slag used as starting material is first screened, then ground and then sieved again. The material was then separated into three fractions. The size ranges of the fractions may vary and are well known to those skilled in the art. The particles in the various fractions can be, for example, particles larger than 6.3 mm, 6.3 to 2.5 mm and smaller than 2.5 mm. It should be noted that such treatment and fractionation of slag is well known and is also used in conventional processes.

Particles larger than 2.5 mm, which make up about 20% of the slag, have a relatively high metal content and are generally suitable for direct processing.

Particles smaller than 2.5 mm may be advantageously processed by the process of the invention.

According to the invention, after reclassifying from this small fraction, the first is passed between rollers which are set apart from one another. Preferably, the rollers are held by a spring or other resilient member in the desired position to allow the rollers to be released when required. The cylinders thus adjusted compress the pieces passing between them only enough to separate the metallic and non-metallic particles along the boundaries in the particle.

The granules thus fractured are then screened to remove a certain amount of oxide material. The screened residue is then passed to a hammer mill where the oxide moieties are completely separated from the metal moieties. Separation is extremely effective as the pre-treatment has already broken the bond between the metallic parts and the non-metallic parts.

The material coming out of the hammer mill is then screened again to obtain an oxide-free aluminum concentrate. The resulting concentrate is fed to a regeneration furnace or passed again between rollers. The passage between the rollers has the advantage that the aluminum concentrate can be further processed in the form of flat flakes. In addition, most of the remaining oxide material is removed during rolling.

According to the invention, further processing of the aluminum flake can be carried out. Methods for doing this include:

1. the aluminum flakes are introduced into a regeneration furnace and there the aluminum billets are prepared. The recovery rate of this operation is substantially the same as the efficiency obtained when regenerating slag pieces larger than 25 mm in diameter.

2. Aluminum flakes can be fed to hammer mills where high purity aluminum pellets are obtained. They have a size of about 2.5 mm or less. Larger pieces split and turn into small balls15 made of virtually pure aluminum. The smaller particles also cleave into balls, but their purity is lower as they mix with the oxides not removed during the process.

3. Pellets consisting of substantially pure aluminum may be introduced into a rege20 furnace and casted from the molten metal from the furnace. The extraction efficiency of the aluminum spikes so produced is better than that of the blocks produced from particles larger than 25 mm.

The hammer mill used in carrying out the process of the present invention consists of a housing, a hub connected to the rotating shaft of the housing and cutting knives attached to the hub. The cutting blades are hinged along the periphery of the hub and have a cutting edge on both sides.

In the hammer mill of the present invention, the slag particles can be dispersed into metallic and non-metallic parts.

Further details of the invention will be illustrated by way of example in the drawings. In the drawing it is

Figures 1A and 1B illustrate together a schematic diagram of an apparatus for carrying out the process of the invention.

Figure 2A shows a slag grain having a size of about 6 to 19 mm and an aluminum content of 65 to 75% by weight;

Fig. 2B shows a slag grain similar to that of Fig. 2A, in which the metal particles are larger,

Figure 3A shows a slag-like particle as shown in Figure 2A after the material has passed through the rollers,

Figure 3B also shows slag particles passing through the cylinders, where the metallic particles are of the size shown in Figure 2B,

Fig. 4A shows a particle of aluminum concentrate coming out of the beating mill, a

Figure 4B also shows a particle size of aluminum concentrate coming out of the smelter, where the aluminum particles are larger than those of Figure 4A.

Figure 5 shows a piece of aluminum concentrate that has passed through the second pair of rolls and is already in flattened form,

Figure 6 shows aluminum particles that have already been removed from the beating mill and have undergone further purification,

Fig. 7 is a sectional view of a cutting blade 60 used in a hammer mill according to the invention,

Fig. 8 is a cross-sectional view of the hammer according to the invention and a

Figure 9 is an axial sectional view of a beating mill according to the invention.

It will be noted first that the process of the present invention

A mixture of various oxides obtained with slit -3181419 and aluminum powder, which can be used well in, for example, heat-generating reactions, preferably in the steel industry, are also commercially available. The aluminum powder embedded in the non-aluminum particles is oxidized during the process and accordingly generates significant heat during steel production. Metallurgists are well aware of this fact, and as energy becomes more expensive, it is increasingly important for the steel industry to improve the quality of the steel without significantly increasing its energy input. This is, of course, just one of the uses of the blend of aluminum and various oxides, which we have mentioned in the light of the energy issue. Otherwise, the skilled artisan will recognize the fundamental importance of recovering the metal content of various slags, such as aluminum forms, and the general steps of this process are well known.

Slags containing aluminum, aluminum alloys and similar metals are available from metallurgical plants. Of course, these slags consist of particles of different sizes and pieces. The size of the pieces can reach up to 30 cm. A portion of 45,000 kg of aluminum formwork can have a metal aluminum content of 75-80% by weight. However, this aluminum content is present in the slag along with other non-aluminum contaminants. As mentioned earlier, larger pieces usually contain a higher percentage of aluminum than smaller pieces. By aluminum we mean not only pure aluminum, but also aluminum in the form of an alloy. Slag pieces larger than 50 mm in size can be processed well in regeneration furnaces using conventional techniques. The use of the method of the invention for pieces of this size is less significant than for pieces of smaller size. In other words, relatively small amounts of oxides and higher metal contents in relatively large pieces cause less problems during regeneration. However, as the slag size decreases, the difficulty of recovering the metal increases. The smaller the slag pieces, the larger their relative surface area. However, the introduction of material with a relatively large surface area into the regeneration furnace impairs the thermal balance of the furnace. Thus, the smaller the slag pieces, the higher the proportion of the oxide layer surrounding the metallic core. The oxides thus isolate the aluminum in the slag particles and thus the fluxes can be less effective in removing the oxide coating from the metal particles. Because of their lower density, a significant part of the released metal particles are sufficient at the furnace temperature. Accordingly, as discussed above, conventional methods can essentially only effectively extract metal from slag pieces larger than 50 mm, with an efficiency of about 90%, while smaller pieces, such as 2-3 mm particles, can rapidly recover the metal content. decreases and up to half of the metal content can be recovered. Accordingly, the process of the present invention is particularly useful for treating slags with a relatively small particle size.

Figures 1A and 1B show a production line for carrying out the process according to the invention. Figure 1B is a continuation of Figure 1A in a horizontal direction. After the slag has been ground and screened for smaller particles, such as the 2.5-6 mm fraction, it is introduced into the addition funnel 10 and fed to the double screen 14 by means of an elevator 12. It is to be emphasized that the efficiency of the process can be greatly enhanced by adding well-selected, uniform particle size pieces to the addition funnel 10. The particle size of the fractions introduced into the addition funnel 10 may conveniently be divided into the following ranges:

0.6mm to 1.3mm

From 1.3 mm to 2.5 mm

2.5mm to 6mm 6mm to 13mm 13mm to 25mm 25mm to 38mm and 38mm to 50mm.

Of course, the ranges given are for the purpose of selecting the desired particle size only and are not mandatory for the practice of the invention.

Figures 2A and 2B show typical slag particles, where metal particles 20 and other inclusions 23 are contained in the oxidized material 18.

The pieces shown in Figures 2B, 3B and 4B are identical in quality to those shown in Figures 2A, 3A and 4A, but differ in size. For example, the metal in Figure 2A has a metal content of 65% and a size of about 12 mm. However, the slag shown in Figure 2B is approximately 20 mm in size and has a metal content of about 75%.

From the material passed through the double screen 14 shown in Fig. 1, the oxide and aluminum powder having particles smaller than 1.3 mm pass through the openings of the double screen 14 and enter the funnel 22. These particles are collected as a final product in the container 22a located below the funnel 22. Of course, the powder product collected in the container 22a is a mixture of metallic and non-metallic particles, mostly oxides. Thus, within this range, the metallic and non-metallic particles are not separated but transported in a suitably movable container 22a.

The slag pieces that do not pass through the openings of the double screen 14 are led to the magnetic separator 24, in which the iron-containing inclusions (see the inclusions 16 in Figure 2A). The material passing from the magnetic separator 24 is introduced into the hopper 26. From the hopper 26, the material is conveyed by means of a conveyor belt 28 to a vibrator feeder 30, from which the slag pieces fall between the rollers 32.

Preferably, the rollers 32 are elastically embedded rollers spaced apart from one another. The rollers 32 are adjusted by means of springs 33. Thus, as the slag passes, the rollers 32 may deflect if too large or hard slag is inserted between them. For example, when a fraction of 2.5 to 6 mm is introduced between the rollers 32, they are adjusted to have a spacing of about 1.3 mm. The distance will, of course, vary with the size of the fraction introduced, but is always smaller than the smallest particle size for that fraction. The rollers 32 are adjusted so that the slag pieces passing between them are slightly pressed together. This ensures that the slag pieces do not essentially fall apart, only the boundaries between the metallic and non-metallic parts are broken. The spring force acting on the rollers 32 is adjustable, so that the force exerted by the rollers 32 can be varied depending on the size of the slag pieces.

The effect of the rollers 32 can be clearly seen from the comparison of Figures 2 and 3. Figures 2A and 2B show slag pieces prior to introduction between rollers 32, and Figures 3A and 3B show slags emerging from rollers 32. In Figure 3, it can be seen that the fractures between the metallic and non-metallic portions are broken and fractures 21 appear. Of course, the tiny inclusions on the surface of the piece break during rolling.

With the 32 cylinders 4181419 used in the apparatus of the present invention, the slag pieces are treated in a substantially different manner than in conventional cylindrical dowels, where the slag pieces are substantially completely crushed and most of them become powdery. In doing so, the oxide inclusions 18 are about rolled into the metal particles 20, which subsequently makes it difficult to separate them. However, according to the invention, the parts are only loosened by the limited pressure of the rollers 32, thereby facilitating the subsequent separation of oxides and metallic parts. For this reason, the pressure of the rollers 32 must be controlled by springs 33 so that the larger pieces do not crush or suffer the necessary deformation. However, it is noted that the rollers 32 may also be formed with fixed bearings and the springs 33 missing from the apparatus. Of course, the structure is still functional, but in this case, it is advisable to adhere very closely to the fractional boundaries to prevent larger particles from passing through and breaking.

The slag pieces coming out of the rollers 32 are placed on the conveyor belt 34, which feeds them into the hopper 36. From a metering hopper 36, a bucket 38 conveys the slag pieces to the shaker screen 40. Here, the small particle size aluminum and non-aluminum particles pass through the openings of the shaker screen 40 and similarly to the solution described in the first unit, through the hopper 42 into the container 42a. In the container 42a, a powder mixture essentially similar to that in the container 22a is collected.

From the shaker screen 40, the slag pieces are fed to 44 hammer mills. The hammer mill 44 is a device well known to those of ordinary skill in the art in which previously shredded slag pieces disintegrate into metallic or non-metallic particles. In preparation for this operation, the passage between the rollers 32 is extremely important, during which the boundaries between the metallic and non-metallic parts are broken, so that the separation can be perfectly accomplished. The material coming out of the hammer mill 44 shown in Figures 4A and 4B is, of course, not a pure metal, but a concentrate with a very high metal content. Most of the surface of the metal particles 20 has already been completely detached from the oxide material 18.

The hammer mill 44 is coupled to a separator 45 which draws air and metal or non-metallic dust particles suspended therein from the air space of the hammer mill 44. These particles are introduced by the separator 45 into the dust container 47.

The particles coming out of the lower part of the hammer mill 44, shown in Figures 4A and 4B, fall on the conveyor belt 46, which conveys them to the feed funnel 48. From here the 50 bucket elevator carries the particles. The bucket 50 feeds the aluminum particles together with the oxide portions not separated by the separator 45 and adhered to the metal surface onto a shaker screen 52. From there, the relatively high metal concentrate can be fed to a magnetic separator (not shown) and then to a vibrator feeder 54. The smaller non-metallic inclusions and the small aluminum particles again pass through the openings of the shaker screen 52 and enter the funnel 56. The metallic and non-metallic particles are collected in the vessel 56a, similar to the previous phases.

In practice, it has been found that during passage between rollers 32, the original oxide content of the slag pieces

It is reduced by 7-8%, and further mechanical stress, such as treatment in a hammer mill 44, removes an additional 11-12% of the non-metallic material.

The material per 54 vibrator feeder is actually a marketable product and can be used without further processing. However, according to the invention, the concentrate can be further treated and the metal content in the material can be further increased. Of course, this requires additional operations, which also increases production costs.

If the material is not further processed after reaching the vibrator feeder 54, it can be processed in a chip furnace and placed on the market in the form of metal stumps. The concentrate at this stage is already in a state free from the vast majority of oxides and can be processed very well in regeneration furnaces. Since their purity is substantially higher than that obtained by conventional processes, their use is obviously significantly more advantageous than conventional processes having the disadvantages mentioned above.

To further purify the material coming to the vibrator dispenser 54, it is again passed between rollers 58 to bring the aluminum particles of the concentrate into a fluffy fluffy form. An example of such an aluminum flake is shown

Figure 5.

Preferably, the rollers 58 are provided with fixed bearings such that particles falling between them from the vibrator feeder 54 are strongly deformed to obtain their shape as shown in Figure 5. The aluminum flakes generally have a thickness of about 1.6 mm, as opposed to 2.5 to 6 mm for the pieces fed into the funnel 10. Of course, the spacing between the rollers can be varied to produce flakes of any thickness. The distance of the rollers 58 may also be adjusted depending on the size of the particles added.

The material passing between the rollers 58 drops to a perforated slide located below, through which small metallic or non-metallic particles pass through. These particles are collected by the funnel 61 and delivered to the container 61a, which contains the same mixture as the containers 22a, 42a or 56a previously described.

The metal content of the flakes falling on the perforated slide 59 is slightly increased relative to the material arriving on the vibrator feeder 54. This also means that at this point in the technology, we are getting a marketable product that can be taken out without further processing. The concentrate in the form of a flake is extremely suitable for the production of metal stumps since their density is higher than that of simple granules and thus can move down the chip furnace relatively quickly. This is important because it avoids the risk of burning in the air.

If the product arriving at the perforated slide 59 is to be further purified, the flakes are again fed to the 60 beating mills. Embodiments of the hammer 60 will be described in more detail below in Figures 7-9. Figures.

The flakes treated in the beating mill 60 are fed through a conduit 80 into the separation cyclone 81. The separation cycle 81 is configured in the well-known manner and the flakes are routed tangentially into the separation space in the usual manner. Here, a low pressure zone is formed in the middle of the separation cyclone 81. The low pressure zone draws in the aluminum and the oxide powder into the central portion and from there the powder is transported through the pipe 83 to the dust bag 92. Below the dust bag 92 is a container 92a. This is similar to the 22a, 42a etc. shown earlier. containers. Heavier metallic particles fall down in the separation cyclone 81 and enter a second beating mill 78. The hammer 78 is positioned just below the separation cyclone 81 and through the connecting pipeline 84 the material coming out of it is placed in another separation cyclone 85. The isolation cyclone 85 works in exactly the same way as the isolation cyclone 81 and the central low pressure zone5.

From -5181419, the powder also enters the conduit 83 and from there through the reels 92 'to the container 92a.

From the separation cyclone 85, the product comes out in the pellet form shown in Figure 6. The pellets fall into the sieve 88 and the powdered portions are introduced through the hopper 96 into the known container 96a. The aluminum pellets obtained here are substantially cleaner than the flakes shown in Figure 5 which were treated in the hammer 60 during the process. Namely, in the separation cyclones 81 and 85, the oxides are substantially removed from the surface of the metal particles together with the aluminum powder. All of these pass through the apertures of the 88 screens. The pellets coming from the sieve 88 enter the funnel 98, from which the finished product is placed in the container 98a below.

The final product collected in the container 98a is, of course, substantially more pure than the materials obtained in the process. It is also obvious that the production of the final product collected in the container 98a is more expensive than the production of the intermediate products mentioned above. However, they have a lower metal content than the final product. Based on all of this, the user of the process may choose to produce an intermediate of relatively lower purity but less expensive or a higher purity and cost. The decision can be influenced by many factors, such as the market situation or technical parameters.

The beating mills 60 and 78 shown in Figure 1 produce the pellets shown in Figure 6 using conventional and generally blunt beating knives.

However, according to the present invention, the hammer mills 60 and 78 may be formed in a special manner so that the final product collected in the container 98a also appears in a flat fluffy form.

Figures 8 and 9 show details of the hammer 60. The apparatus is housed in a housing 62 and comprises a hub 64 mounted on a shaft 66. The shaft 66 is preferably driven by an electric motor, clockwise in the embodiment shown in FIG. The hub 64 mounted on the shaft 66 is provided with cutting blades 68. The cutting blades 68 are pivotally mounted along the periphery of the hub 64 by means of the retaining members 70.

Figure 7 is a cross-sectional view of the cutting blades 68. The figure clearly shows that the cutting blades 68 are provided in both directions for slicing the concentrate pieces. Of course, during operation, the cutting blades 68 only cut in one direction, but the bidirectional design of the edges allows the cutting blades 68 to be turned in reverse after being worn on one side. This significantly increases the service life of the cutting blades 68. The cutting blades 68 are provided with holes 72. The holes 72 are formed at both ends of the cutting blades 68. This allows the cutting blades 68 to be fastened in different ways.

The upper part of the apparatus is provided with 74 inlet stubs. This passes the material to be treated into the hammer 60. At the same time, the inlet nozzle 74 also draws in a significant amount of air.

The lower part of the housing 62 has apertures 76. Their size is chosen so that the material in the hammer cannot escape before being cut into slices of suitable thickness. Only after the appropriate size has been reached can the particles pass into the hammer 78 shown in Figure 1B.

The construction of the hammer 78 is identical to that of the hammer 60. However, the apertures 76 in this apparatus are smaller in size, i.e. the aluminum concentrate flakes will be smaller in size out of the hammer 78 than in the previous case. 1B and FIG

Figure 8 shows that the aluminum flakes coming out of the hammer 60 through the apertures 76 fall into the lower part of the housing 62, from which they exit through the conduit 80. Pipeline 80 feeds the material to the separation cyclone 81.

The hammer 60 draws a large amount of air through the inlet nozzle 74, as we have said. As a result, flow occurs inside the hammer mill 60 and within the pipeline, causing the material to pass through the pipeline 80 into the separation cyclone without any additional equipment.

From the release cyclone 81, the aluminum flakes enter the beat mill 78, from where the further shredded concentrate passes through pipe 84 similar to pipe 80.

In summary, the process and apparatus of the present invention can be used to produce metal concentrates of various purities from metal-containing slag particles which had no practical value in conventional methods. In addition, the powder mixture collected during the various stages of the process, comprising partly metal particles and partly oxide particles, can also be sold as it can be used in various applications, such as steel production.

An essential step of the process of the invention is the passage of the slag pieces between the rollers and their breaking in the hammer mill, which results in the removal of most of the oxide material from the metal concentrate. It is also important that the rollers are as flexible as possible in the bearings so as to achieve a perfect crushing pre-press, as discussed in detail above.

In the hammer mill, the metallic and non-metallic parts of the pre-pressed pieces are effectively separated, that is to say by a high degree of cleaning. Thus, the material obtained after the treatment in the hammer mill is practically already usable, for example, ingots can be cast from the metal concentrate after melting in a regeneration furnace.

However, the concentrate, as said, can be further purified if it is again passed through similar cylinders. The metal flake shown in Figure 5 is considered to be a very high quality finished product, but it can still be refined. Thus, the pellets shown in Figure 6 can be obtained at the end of the process.

Various metal shavings can also be used in the process. For example, aluminum chips from a turning operation can be fed directly between the second pair of rolls to obtain a piece of metal chips or metal flakes. The introduced material passes through the stages shown in Fig. 1B, and the beating mills produce a final product of appropriate quality and shape.

The solution described above has been implemented in practice and it has actually been found that the processing of metallic slags can be carried out much more efficiently than before. In addition to the advantages mentioned above, another advantage of the process of the invention is that it can also be used to convert various metal shavings into a highly manageable product.

The process itself is quite simple and the equipment used to implement it can be easily connected to a machine line. The production line used to carry out the process further comprises a completely new unit, namely the beating mill shown in Figures 8 and 9, by means of which the pieces can be cut into regular sheets or flakes.

Of course, both the disclosed method and the embodiment of the device for its implementation are only one example

-6181419 and the invention provides a way to apply these principles in a variety of embodiments.

Claims (26)

Patent claims A method for recovering metal content in metallurgical slags in a concentrated form, comprising: - introducing slags of a certain size range into rolls adjusted to a size range, - compressing the slag pieces between the rolls so that the metallic and non-metallic parts are - chopping the slag pieces in a beating mill and finally - separating the metallic and non-metallic parts. 2. A method according to claim 1, wherein the metallic and non-metallic parts are separated by sieving. 3. A process according to claim 2, wherein the further separation of the metallic and non-metallic parts is carried out in separation cyclones. 4. The process according to claim 2 or 3, wherein the metal powder particles are removed from the metal concentration 25 together with the non-metal parts. 5. A method as claimed in any one of claims 1 to 4, characterized in that particles that are below a certain size are removed from the material before being introduced into the rolls. 6. A method according to any one of claims 1 to 4, characterized in that, prior to introduction into the rollers, the material is passed through a magnetic separator, where magnetic particles are removed. 35 7. A method according to any one of claims 1 to 3, characterized in that between 0.6 mm and 1.3 mm particles are introduced between the rollers. 8. Figures 1-6. A method according to any one of claims 1 to 4, characterized in that particles between 1.3 and 2.5 mm are introduced between the rollers. 9. A method according to any one of claims 1 to 3, characterized in that it is between the rollers The particles are 2.5 to 6 mm in size. 10. A method according to any one of claims 1 to 4, characterized in that pieces between 6 and 13 mm are inserted between the rollers. 11. A method according to any one of the preceding claims, characterized in that pieces of 13 to 25 mm are inserted between the rollers. . 12. A method according to any one of claims 1 to 4, characterized in that pieces of 25 to 38 mm are inserted between the rollers. 13. Figures 1-6. A method according to any one of claims 1 to 3, characterized in that pieces of between 55 and 38 mm are inserted between the rollers. 14. A method according to any one of claims 1 to 3, characterized in that the metal concentrate is introduced between further rolls and the rolls are also arranged at a certain distance to each other and With their help, the particles are turned into thin fluffy pieces. 15. The process of claim 14, wherein the metal flakes are introduced into an impact mill and further non-metallic particles of the metal concentrate are 10 parts are separated. 16. A process according to claim 15, wherein the separation is carried out by means of separation cyclones. 17. Process for the preparation of a process according to any one of claims 1 to 3, characterized in that an aluminum concentrate is prepared. 18. A method for processing irregularly shaped metal particles of a specified size into a metal concentrate of a specified size, characterized in that the particulate blue is introduced between cylinders at a defined distance, the particles between the rolls are formed into thin metal flakes and the metal flakes are milled to form a metal concentrate. 19. The method of claim 18, wherein said metallic particles are aluminum-containing pieces. 20. A 19. ' A process according to claim 1, characterized in that the non-metallic material is separated from the aluminum-containing particles by means of a separation cyclone. 21. A method according to claim 19 or 20, characterized in that the powdered aluminum particles separated from the aluminum-containing particles are transported from the impactor by air flow. 22. A method according to any one of claims 1 to 6, characterized in that, when the slag pieces are introduced between the first pair of rolls, the rolls are set at a distance less than 40 pieces of slag. 23. The method of claim 22, wherein said rollers are displaceably mounted against a spring force. 24. A grinding mill for cutting metal media into slices of a given size, with a housing, an axis rotating in the housing and a hub with cutting blades mounted on the shaft, characterized in that the cutting blades (68) are hinged along the periphery of the hub (64) and provided with cutting edges and an inlet port 50 (74) is provided on the upper portion of the housing (62). 25. An embodiment of a hammer mill according to claim 24, characterized in that the cutting blades (68) are provided with a cutting edge on both sides. 26. An embodiment of a hammer mill according to claim 25, characterized in that both ends of the cutting blades are fixed to the hub (64). 3 drawings, 9 figures Director of Economic and Legal Publishing House 84.5132.66-4 Alföldi Nyomda, Debrecen - Chief Executive Officer: István Benkö Director