FI77266C - FOERFARANDE FOER ATT AVSKILJA METALLFOERENINGAR FRAON VARANDRA. - Google Patents

Description

1 77266

Method for separating metal compounds

The invention relates to a method for separating metallic components made of 5 different shaped aluminum alloys, the method comprising, as a first step (a), obtaining a feedstock containing at least two component types containing different shaped aluminum alloys with different types. melting temperatures.

The packaging or can industry, such as used soft drink cans, which contain at least one or more components made of aluminum alloys, has received increasing interest and extensive research into methods for utilizing aluminum components. The importance of conservation resources and taking care of environmental problems has spurred interest. However, to date, the recycling of such materials has been greatly hampered by the lack of an economically attractive method. For example, attempts to recycle a beverage can with a body made of a single aluminum alloy and a top or lid constructed of a different aluminum alloy often result in an aluminum melt having a composition of neither of the 25 alloys. The value of such a melt is greatly reduced because it is not readily reusable in the can body or lid without large dilutions, cleanings and remixing or other modifications. In other words, it can be seen that there is a great need for a method for recycling cans of the type described, for example, in which their various components are recovered and separated according to the alloy or the type of alloy.

The problem of separating different alloys is found in U.S. Patent 3,736,896, which discloses separating tops or lids made of aluminum-35 alloy from steel-framed cans by melting a narrow strip of 2,726,66 aluminum strips around the perimeter of the can body to provide a separation base that allows the aluminum base to separate. This publication uses induction heating to melt the strip, with the surrounding inductor surrounding the strip and connected to a high frequency power supply. However, this approach seems to assume that the used soft drink can is not crushed and the bottom remains completely round. In addition, thawing the bottoms in this way would not appear to be economical, as the bottoms would have to be removed one by one.

In U.S. Patent No. 4,016,003, cans having bodies and lids made of aluminum alloy are shredded into particles ranging from 25.4 to 38.1 mm and then maintained at temperatures of about 371.1 ° C to remove paints and varnishes. In addition, U.S. Patent No. 4,269,632 shows that conventional alloys used in the manufacture of can bottoms, e.g., Aluminum Association (AA alloy) 5182, 5082, or 5052, and those used in the manufacture of can bodies, e.g., AA3004 or 20 AA3003, differ significantly in composition, and the factory finished can , the base and body are essentially inseparable and that an economical recycling system requires the use of a complete can. U.S. Patent No. 4,269,632 further states that the recycling of cans results in a melt composition that differs significantly from the compositions of both conventional alloys used in the manufacture of the can base and those used in the manufacture of the can body. This patent proposes that both the bottom and the body of the can be made of the same alloy to combat the recycling problem. For can bottoms and hulls made of AA5182 and 3004, it is shown that it is usually necessary to add pure aluminum regardless of the alloy being made.

In view of these problems, the recycling of metal cans, such as aluminum soft drink cans with components made of different alloys,

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3 77266, it would be useful to have a method which would allow the cans to be recovered by separating the components according to their alloys or their alloy type. Thus, by separating the components before thawing, the components can be thawed and reconstituted according to conventional methods, including without expensive dilutions or purification steps.

The present invention, which provides a method for separating metal components made of various aluminum alloys, is characterized in that it further comprises the steps of: (b) annealing the feedstock to a temperature high enough to initiate the onset of melting of the component having the lowest onset melting temperature, thereby increasing the fracture susceptibility of at least one of said ingredients to a level sufficient to cause fragmentation of at least one of said ingredients upon shaking of the annealed feedstock; (c) subjecting said heated feedstock to a shake sufficient to cause rupture of said component having the lowest onset melting temperature; and (d) separating said fragmented components from the remaining feedstock.

According to the present invention, the raw material is annealed to a temperature high enough to initiate the onset of melting of the component having the lowest onset melting temperature. While keeping the products at the lowest starting melting temperature of said aluminum alloy component, they are mixed so that mixing is sufficient to cause the aluminum alloy component having the lowest starting melting temperature to fragment and detach from the product. The fragmented and detached components are then separated from the products and recovered.

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In the accompanying drawings, Fig. 1 is a flow chart illustrating steps that may be used to sort cans, such as used soft drink cans, Fig. 2 is a bar graph showing the grain size distribution of the oven and the material leaving the oven at 571 ° C, Fig. 3 is a bar graph, shows a grain size distribution of the material entering and leaving the furnace at 582 ° C, Fig. 4 is a bar graph showing the grain size distribution of material entering and leaving the furnace at 593 ° C, Fig. 5 is a bar graph showing the grain size distribution of the material entering and leaving the furnace and the oven at 604 ° C, Fig. 6 is a flow chart illustrating steps that may be used to sort cans and remove incidental contaminants therefrom in accordance with the invention; and Fig. 7 is a flow chart illustrating steps that may be used to remove finely divided material from cans. ierrätysprosessissa.

Referring to the flow chart of Figure 1, the products used from which the aluminum alloy components will be recovered or separated may include cans such as food or soft drink cans. Cans for which the method is suitable are used soft drink cans consisting of two different aluminum alloys. It can be seen from the flow chart that the products to be recovered can be preliminarily sorted to remove materials that would contaminate the aluminum alloy to be recovered. For example, it would be desirable to remove glass bottles and steel cans, such as those used for food. In addition, it is desirable to remove other materials, such as

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5 77266 ka and sand, etc., for example to reduce the amount of silicon that may be present in the separated alloy. Removal of these materials may allow the alloy obtained in accordance with this invention to be used without further purification methods. Preliminary removal of steel, which may be in the form of tanks or cans or of other origins, helps to keep the iron in the recovered alloy at a level that does not adversely affect the properties of the recovered alloy.

When the materials to be recovered are food or soft drink cans, they are usually packed in bales for shipment and therefore the bales would normally be broken up before the sorting step to remove foreign materials.

After the sorting step, the cans can be varnished. This can be done by solvent or heat treatments. Varnishing removes coatings, such as decorative or protective coatings, which may contain elements such as titanium, the presence of which in high concentrations is not normally desirable in recoverable aluminum alloys. When using a solvent for varnishing, it is usually desirable to tear into strips or perforate the cans to allow the solvent to drain away. When the coatings are removed by heat treatment, the temperature used is usually in the range of 316 to 538 ° C.

In the next step of the process, especially when the cans are used soft drink cans with bodies made of, for example, Aluminum Association alloy (AA) 3004 and lids of AA5182, the cans are heated to a temperature at which the lid made of AA5182 becomes fracture sensitive. This temperature has been found to be in close correlation with the temperature of the onset of melting or grain boundary melting of the alloy.

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Thus, with reference to the soft drink cans used, this is the initial melting temperature of AA5182. By the onset of melting or grain boundary melting temperature is meant herein lower temperatures of the melting range or phase melting range and temperatures slightly below the point at which the fracture susceptibility of the alloy develops or significantly increases or where alloy fragmentation can occur without high force. In other words, under fracture-sensitive conditions, fragmentation can be made to occur by using a drum treatment or dropping, and the use of forces that would be produced by a hammer mill or jaw crushers is not necessary. The forces exerted by the hammer mill or jaw crusher are detrimental to the immediate process because, for example, they crunch the cans and thus trap the material to be separated. It should be noted that many alloys have different onset melting temperatures. For example, the initial melting temperature of AA3004 is about 630 ° C and the initial melting temperature of AA5182 is about 20,581 ° C and the phase melting range is about 581-637 ° C. However, it should be noted that this interval may vary to a large extent depending on the exact composition of the alloy used. The onset of melting or grain boundary melting of the alloy greatly reduces its strength and results in fracture-to-25 ratios. Thus, lids made of AA5182 can be removed or removed from frames made of AA3004 because the lids have been placed in a condition that makes them very susceptible to breakage and fragmentation. In this mode, energy, for example drum handling, can be used to remove or remove the lid from the can body. Detachment is primarily due to breakage or fragmentation of the lid, resulting in lid particles that are not only smaller than the can body, but are usually smaller than the lid.

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Thus, after the detachment step, a load or mass is formed consisting of can bodies and fragmented lids, the can bodies being formed of an alloy or material different from the lids, the fragmented lids having a substantially different grain size distribution than the can bodies. Thus, it can be seen that not only is it important to remove the lid from the can body, but the grain size of the lid pieces must be substantially different from the can body. To obtain a product or alloy that is not adversely contaminated with the alloy with which it is mixed, the load is treated to sort or separate the particles. When this aspect of the process is carried out, the result is pieces of lid or metal parts consisting essentially of the same alloys separated from the can bodies.

Although the method has been generally described for the utilization of used soft drink cans, it is to be understood that the feedstock of the method is not necessarily limited thereto. The method can thus sort aluminum alloys, in particular kneaded alloys, in which one of the alloys can be made fracture-sensitive or in a state where one of the alloys can be selectively broken into pieces, resulting in a reactive size distribution different from the grain sizes of the other alloys. In this way, the alloying can be performed. Thus, the feedstock to be fed for recovery may consist, for example, of used soft drink cans with bodies made of AA3004 and lids of AA5182. Other alloys that can be used in the covers include AA5082, 5052, and 5042 (Table X). However, other alloys that can be used in food or soft drink can bodies include alloys such as AA3003, 8 77266 AA3104, AA5042 and AA5052 (Table IX). For example, if such alloys have a high magnesium content, it is necessary that such can bodies be broken or broken into pieces sufficiently to allow them to be coated with lid alloys such as AA5182. Thus, it is to be understood that the method of the present invention is not only capable of removing and sorting lids from can bodies, as mentioned herein, but is also capable of sorting alloys of can bodies 10 with lids when the alloys are similar in composition and behave similarly. fracture or fragmentation properties will occur, as explained herein.

In addition, when the cans have bodies and lids made of the same alloy, this can also be recovered by sorting in accordance with the present invention. For example, if the can body and lids are made of a sheet having a composition of 0.1 to 1.0 wt% Si, 0.01 to 0.9 wt% Fe, 0.05 to 0.4 wt% Cu, 0 .4 to 1.0% by weight of Mn, 1.3 to 2.5% by weight of Mg and 0 to 0.2% by weight of Ti, the residue being aluminum and incidental impurities, this would be sorted according to the invention. Thus, if the feedstock to be recovered comprises spent cans made from mixed alloys such as rail 3004, 5182, 5042, as well as the can of the can body and lid above, this alloy would presumably be sorted into AA3004 body lid. because no onset of melting would occur when the temperature was high enough to cause AA5182 or AA5042 to rupture.

Similarly, if the feedstock contains steel cans to which a lid made of 5182 is attached, the lids could be sorted in accordance with the invention and the steel bodies would be recovered with can bodies made of 3004. The steel can bodies can be separated from the aluminum alloys with which they can be sorted, for example by magnetic separation after the lids 9 77266 have been removed. If the steel-framed cans had lids that would break at temperatures between the onset of melting of AA3004, then it would be necessary to heat the cans to a higher temperature compared to 5 AA5182 to cause the lid to detach from the steel body, after which the steel bodies could be removed by magnetic separation.

It can be seen from the above that the method according to the present invention is not very sensitive to the aluminum raw material to be recovered. In other words, the process is capable of handling most types of aluminum alloy and is particularly suitable for the recovery and sorting of hard alloy products such as used cans. If the scrap metal consisted of automotive aluminum alloys, for example AA6009 and AA6010, as described in U.S. Patent 4,082,578, in which the material used may be hoods and doors, etc., it may be desirable to tear such products to obtain a fluid throughout. mass. Or o-20 when recovering AA2036 and AA5182 from used cars, it may be desirable to rip such products and then effect separation, as mentioned herein.

With respect to the grain boundary melting or onset melting of a single aluminum alloy component that causes fracture sensitivity or fragmentation, it is to be understood that this is an important step in the process and must be performed with some care. Again, using the soft drink cans used as an example, it should be noted that temperature control is important at this stage. In other words, if the temperature is allowed to rise too high, substantial melting of the cover made of AA5182 may occur, which may result in aluminum and magnesium losses due to oxidation. In addition, temperatures that cause substantial melting of the metal should generally be avoided because coagulation of the granules with molten aluminum may result in the formation of a mass that is not easily flowable compared to finer discrete granules. In addition, molten aluminum can stick to the furnace and begin to grow a layer of metal and granules there, which, of course, interferes with the efficiency of the entire work phase. Sorting of solidified pulp also becomes much more difficult, if not impossible. Finally, in smelting, a finely divided material such as sand, glass, dirt and pigments or impurities such as silica, titanium oxide and iron oxide tend to sink into the molten metal, making the separation even more difficult. Thus, in view of the above, it can be seen why temperatures leading to a substantial melting of one aluminum alloy component should be avoided.

Similarly, when temperatures that are too low are used, the fracture sensitivity of the lids decreases sharply and the resistance to fragmentation increases substantially, with the result that separation becomes very difficult and often separation cannot be achieved. Thus, it is seen that it is important that the temperature is high enough to remove the lid from the can body. For lids formed of AA5182, this temperature is approximately proportional to the onset melting temperature of about 581 ° C. The melting range of AA5182 is about 581-637 ° C. Thus, if used soft drink cans are heated to 25,593 ° C, this is well below the melting range of AA3004, about 630 to 654 ° C, and the lids can be removed or removed; without breaking the frames of the can.

With respect to grain boundary or incipient melting, it is to be understood that since the sheet from which the lids are made is rolled thin, the granules are not precisely bounded. However, it is believed that recrystallization occurs when used soft drink cans are heated, for example, to remove varnish, which can occur at, for example, 454 ° C. Thus, grain boundary melting may occur.

When the used beverage cans were heated to a temperature of about 593 ° C or slightly above, it was usually found that the bottoms made of AA5182 sank or settled into the body of the can made of AA3004. However, when the cans were shaken at approximately this temperature, for example by letting them fall off the belt conveyor, the lids were found to detach from the can bodies and disintegrate or fragment into small granules while the can bodies were relatively unchanged. Vibration sufficient to remove the bottoms can also be achieved in the blast furnace while the cans used are heated to a temperature between 581 and 624 ° C, with a preferred range of 581 to 610 ° C and typically no more than 604 ° C. The vibration sufficient to remove the bottoms in the blast furnace may be that which occurs at these temperatures as the cans roll inside the furnace. As noted above, forces such as those obtained by hammering or using jaw crushers should not be used because they flatten the cans or otherwise trap fragmented bottoms with the can bodies. As previously noted, operating at high temperatures in the melting range can lead to too much molten metal and consequent problems. The melting problem becomes particularly acute if the soft drink cans used are kept for a relatively long time at the high temperatures of the melting interval. At temperatures between 581 and 25,610 ° C, the time corresponding to the temperature can range from 30 seconds to less than 10 minutes.

At the sorting stage, the AA5182 pieces can be separated from whole can bodies or can bodies that have been torn by screening. However, it is to be understood that other separation methods may be used, all of which are considered to be within the scope of the present invention.

Looking at the invention from yet another aspect, as illustrated in Figure 6, it has been found that dirt such as clay, sand and glass used in connection with the soft drink cans used can be effectively removed in accordance with the present invention. On the other hand, for the recycling of soot 2 77266, it must be taken into account that dirt such as clay and sand, etc., can lead to concentrations of constituents such as recovered metal silicon that are higher than allowed in the composition ranges of the 5 alloy. Thus, in order to obtain alloy compositions that meet the quality requirement, purification, substantial dilutions, or some kind of remixing are required, all of which greatly reduce the economic feasibility of recycling. Thus, not only should the alloys of different components, such as soft drink cans, be distinguished according to the alloy, but it is essential that the presence of adventitious impurities such as silicon is prevented, as this can also lead to an alloy that does not meet quality requirements.

Although reference has been made primarily to clay and dirt, it is to be understood that these materials can lead to fouling in the form of calcium, sodium and silicon. Silicon often occurs in the form of silica. Other impurities si-20 include oxides of iron, lead, and aluminum, magnesium, and titanium, which are often formed as a result of oxidation during furnace processing. One source of TiCl 2 is can coatings. In the present invention, these impurities are considered to be adventitious impurities because they are impurities that have entered during or after use of the cans and are not usually due to the mixing of the alloys with each other. However, adventitious impurities are not necessarily limited to said impurities.

It should be noted that the addition of high purity aluminum to dilute impurities such as silicon is also detrimental to the economic viability of recycling. This problem is solved in the present invention by enriching contaminants, such as silicon, in a manner that allows them to be removed from the system.

In the recycling of cans, such as

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13 77266 soft drink and food cans, as previously mentioned, it is common to remove coatings, such as decorative and protective coatings, by heating. Thus, the cans can be maintained at temperatures between 316 and 538 ° C, as previously mentioned, to remove these coatings. However, while this treatment is suitable for removing coatings, it causes the clay and dirt in the can to dry. Thus, remelting of scrap metal from which varnish has been removed, dried sa-10 vi or dirt would melt, thus increasing the problems of obtaining a useful alloy. In the present invention, it has been found that rupture of the base promotes the formation of smaller particles which remove dried materials, such as clay and dirt, from the surface of the cans. It is believed that the removal of such material from the surface is accomplished, for example, by abrasion caused by fine lid particles on the surface of the can body. If the heating to the fracture-sensitive space is carried out in a blast furnace, the abrasion outside the larger bodies caused by the smaller particles is caused by the rotation of the furnace. If a conveyor-type oven is used, grinding or rubbing can be accomplished when the cans are shaken to break the fracture-sensitive material.

It should be noted that it is important not only to remove dried clay or dirt materials from cans, but to obtain dried materials in a form that allows them to be separated from the feed materials. Thus, this is preferably accomplished by grinding the dried clay or dirt to a fine particle size. That is, the dried clay or dirt pi-30 should be ground to a grain size smaller than the minimum grain size of any recyclable component. Thus, for example, when the recyclable feedstock is mainly cans with aluminum alloy bodies and aluminum alloy lids or bases, for example bodies 35 made of AA3004 and lids made of AA5182, it is usually preferred that the contaminants due to dried clay or dirt 14 77266 separated from the can bodies by broken components. The ground clay or dirt can then be separated from the broken components, for example the lids. That is, heating and vibrating 5 reduces the grain size of the dried clay or dirt that can be separated from the broken lids. This separation can be achieved by screening. Thus, in a preferred embodiment, the fine granules resulting from the dried clay can be effectively separated from the lids using, for example, a 20 mesh screen (US standard series), depending on the amount of random impurities to be removed and balanced by the amount of fine metal particles. It will be appreciated that other means of separation, for example air scraping or flotation techniques, may be used, and any such or similar separation is considered to be within the scope of the invention.

It should be noted that in the recovery of alloys, the tolerance to elements such as silicon may vary depending on the alloy. For example, in alloy-20 rings with a high silicon content, silicon cannot be considered an impurity. Thus, the use of silicon in the present invention is intended to be an example and not a limitation. Thus, in the following illustrative representation, silicon is referred to by way of example only.

Looking at the invention from yet another aspect, as illustrated in Figure 7, it has been found important to remove finely divided metal from the process. That is, when it has been found desirable to tear aluminum products, e.g., used aluminum materials such as used cans, it has been found that tearing results in a substantial amount of finely divided metal, referred to herein as a finely divided material. Normally, the emergence of such a finely divided material would not be considered a significant problem. However, when vir-35 soft drink cans are treated to separate the lids from the can bodies, the lids are broken into pieces as described herein and are substantially smaller in size than the bodies, allowing for separation. However, if the materials used, for example the used soft drink cans, are torn before the separation treatment, the tearing can lead to the formation of such a fine material over the entire range comprising the pieces of the lid. In fact, the finely divided material formed by tearing can be said to contaminate the fragmented portion. For example, if a soft drink can comprises 75% by weight of AA3004 and 25% by weight of 10 AA5182, the finely divided material formed by tearing the feedstock consisting of such cans may contain 93% by weight of AA3004. and only 7% by weight of AA5182. Thus, it is seen that it is very necessary to prevent this type of fouling in the present method. Failure to take into account the removal of finely divided material will result in contamination of the fragmented portion of AA5182 with fine-grained AA3004 from the can bodies. Thus, it has been found that the removal of finely divided material over a size range corresponding to the size range of the fragmented portion separated from the portion of the can bodies results in substantially fragmented portions that are substantially free of finely divided material. The finely divided material should be removed after the tearing step and before the shredding step. One way to remove finely divided material may be to use screens, although other methods, such as air separation and the like, are considered to be within the scope of the invention.

When the feedstock to be used consists of soft drink cans having, for example, bodies made of AA3004 and lids made of AA5182, after tearing, the finely divided material may contain 1-15% by weight or more of torn feedstock.

The following is an example of fouling that can be caused by finely divided material generated during tearing. From Table X, the composition range for AA5182 manganese is 77266 is 0.20 to 0.50% by weight. Typically, AA5182 manufacturers keep the manganese composition close to the center of this range. For the following examples, it is to be assumed that a manganese content of 0.38% is desirable.

5 If the tearing process and the subsequent fragmentation are carried out on 100 units of used soft drink cans, it has been found in one case that the manganese content of the five units of hay-forming material generated during the tearing step was 1.10%. Thus, these consist almost exclusively of the yk-10 synonym of AA3004. The expansion step yielded 20 units of AA5182 with a manganese content of 0.38%. If these 25 units are not separated but collected together, the resulting manganese content can then be calculated to be 0.52%. This requires considerable dilution to produce a metal with a manganese content of 0.38%.

In yet another example, if the process produces a shredded product or raw material containing about 9% by weight of finely divided material, the manganese content of this material is 1.05% by weight. If these 9 units were collected in 20 fragmented portions together with 20 units of AA5182, the manganese content of the combined 29 units would be 0.59% by weight. Again, this requires significant dilution with pure aluminum to produce AA5182 with a manganese content of 0.38% by weight. Thus, it can be seen that it is important to remove the finely divided material before it mixes with the fragmented portion.

The bales formed from food or soft drink cans referred to above can be broken up by a tear-like procedure. The raw material fed after tearing should be screened to remove fine metal for the purposes detailed below. As shown in Figure 7, the finely divided material can be de-varnished and then recombined with a miscible portion of the feedstock in accordance with the invention and optionally melted.

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As a further example of the invention, used soft drink cans with bodies made of AA3004 and lids made of AA5182 were treated by passing them through a rotary type oven. Material entering and leaving the blast furnace was sampled at four different furnace set temperatures as follows: 571 °, 582 °, 593 ° and 604 ° C. Samples taken from the incoming material weighed approximately 15 kg (35 Ib). About 6 minutes later, representing the residence time of the soft drink cans used in the oven, a sample of about 45 kg (100 lb) was taken from the exiting material.

The bales of soft drink cans used before entering the ovens were treated with a shredder. In the process where most cans are partially shredded, the tear-15 mixer produces some fine material from the soft drink cans used. The figures compare the screening analyzes of incoming and outgoing material at each set temperature of the furnace to determine the extent to which bottom fragmentation e-20 occurs within the furnace. This is observed as a decrease in the weight of the coarser fractions and an increase in the weight of the finer fractions.

The U.S. standard screen sizes used to fractionate the samples are listed in Table I, along with the corresponding Taylor mesh sizes.

Samples of each size fraction were thawed and analyzed to monitor the alloy concentration and also to measure the amount of random impurity involved.

The chemical composition of the sample makes it possible to calculate the relative amount of AA3004 and AA5182 present. This is done assuming that AA3004 contains 1.10% manganese and that AA5182 contains 0.38% manganese. It can be shown that the melt formed from the soft drink cans used, with a manganese content of 0.92%, contains 75% AA3004 material and 25% AA5182 material. This calculation was performed for each exiting fraction at the four oven temperatures of the experiment. The calculated amount of AA5182 present is shown in the bar graphs of Figures 2-5 as a fully shaded portion.

Figure 2 shows the grain size distribution of the incoming and outgoing material 5 at an oven set temperature of 571 ° C.

The distribution of AA5182 in the starting material is also shown. The temperature recorded during the sampling step ranged from 554 to 571 ° C. The most important feature in the figure is that very little difference is seen in the grain size distribution 10 of the incoming and outgoing material. It is also seen that the mixture of AA5182 and AA3004 in the coarser leaving fractions is about 25% and 75%, respectively, indicating that no lid fragmentation appeared to occur at this temperature.

Table II shows the spectrographic analysis of the detected metal in each size fraction for both incoming and outgoing material. Again, the inbound and outbound material appear to be very similar for a given size fraction, with the exception of magnesium.

However, there appears to be a size fraction-dependent variation in composition, suggesting that in the crushing step, prior to de-varnishing, more fine material from the body is generated than fine material from the bottom. The manganese contents of the finer fractions appear to have increased and the magnesium-25 siium contents decreased compared to the coarser fractions. Thus, the AA3004 content of these finer fractions appears to be higher than that of the coarser fractions.

Because the body of the can is thinner than the bottom and because it covers a larger portion of the surface of the can than the bottom, it can be expected that the body of the soft drink cans used when tearing would produce more fine material than the bottom. The decreasing magnesium content in connection with a finer grain size may also reflect the increased oxidation of magnesium caused by the melting of smaller material for analysis. -10 mesh material, both inbound and outbound, was not sufficiently contained in the metal

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19 77266 list of material to be melted and to produce a sample for spectrographic analysis.

Data from samples taken at an oven setting temperature of 582 ° C and 593 ° C are shown in Figures 3 and 5 and Tables III and IV, respectively. These samples show fragmentation of the AA5182 lids inside the rotary kiln. In particular, the amount of finer mesh fractions in the outgoing material increases compared to the incoming material; and the composition of this fine material shows the enrichment of AA5182. This trend is stronger at 593 ° C than at 582 ° C.

Samples taken at 604 ° C provide the strongest conclusive evidence for AA5182 kiln fragmentation. The weight of the two coarsest fractions has dropped significantly after passing through the furnace, and the weight of all four finer fractions shows a significant increase (Figure 5). The compositions of the fractions (Table V) show that the coarser fractions are close to the commercial grade composition of AA3004 and that the finer material 20 is close to the commercial quality composition of AA5182. A comparison of the data from the 571 ° C and 604 ° C experiments shows the migration of AA5182 from the coarse fractions to the fine fractions.

Table V shows that the metal of the -10 mesh fraction of the 604 ° C sample contains 0.50% silicon. This is significant because this fraction represents about 30% of the AA5182 of the system. This material was further screened to determine the possibility that random silicon purities could be screened out. The results are shown in Table VI. The random silicon apparently travels to -20 mesh1 in fractions. The -25 mesh fraction contained such a large amount of non-metallic material that it could not be melted to prepare a sample for spectrographic analysis. Visual inspection revealed significant amounts of glass and sand. The chemical analysis of the -25 material is shown in Table VII. 35 This fraction contains only about 56% metallic aluminum. The content of sand and glass is about 23% by weight, and the content of iron of about 20,772 6 6 hours is about 1.7% by weight. Discarding all -20 mesh material to minimize the adventitious presence of silicon and iron contributes to a 2.2% system loss. However, this material contributes o-5 to the formation of slag and should therefore be removed before smelting.

It should be noted that certain alloys tolerate occasional contaminants, such as silicon, better than others. Referring to, for example, AA3004 and AA5182, it is noted that the content is 0.30% by weight maximum for AA3004 and 0.20% by weight maximum for AA5182. In addition, it can be seen from Table V and Figure 5 that, as a result of adventitious impurities, silicon can exceed these concentrations. By considering the weight% and silicon content of each fraction, the amount of silicon in the fragmented component can be calculated. For example, in the illustrative example, the amount of silicon in AA5182, Table V, (without removal of adventitious impurities) is 0.30% by weight of silicon, well above the 0.20% by weight limit set for AA5182. However, the removal of adventitious impurities in accordance with the invention, for example, by removing from the AA5182 fraction the material that pierces the screen of U.S. Pat. No. 20 (Table IV), produces AA5182 with a silicon content of only 0.17% by weight. It is to be understood that 50% more silicon-free material would be required to reduce the silicon-25 content from 0.30% to 0.20% by weight. Furthermore, it is to be understood that the fractions used and referenced in the tables are only examples and are not intended to limit the scope of the invention, as different alloys may tolerate different concentrations of impurities.

In the experiment using whole cans, the soft drink cans used were treated in a test apparatus at about 599 ° C. Fragmented base pieces accounted for 25.3% of the weight of a can that had been varnished. 35 The share of hull parts was 74.7%. This suggests that the alloy separation efficiency was close to 100%. The two o-21 7 72 6 6 ores were thawed and analyzed. The results of the spectrographic analysis, which can be compared with AA5182 and AA3004 (see Tables IX and X), are shown in Table VII. These analyzes further support that a 5% separation of the two alloys is possible when the starting material is whole cans.

Table I

Sieves used to fractionate the samples 10 U.S. Standard Sieve (US) - Equivalent screen opening (mm) Tyler mesh value 2 inches 50.8 2 inches 1 inch 25.4 1 inch ^ 5 0.5 inches 12.7 0.5 inches 0.265 inches 6.73 3 mesh No. 4 4.76 4 mesh No. 7 2.83 7 mesh No. 10 2.00 9 mesh 2q No. 14 1/41 12 mesh No. 18 1, 00 16 mesh no. 20 0.84 20 mesh no. 25 0.71 24 mesh 22 7 7 2 6 6

Table II

Chemical analyzes of incoming (IN) and outgoing (OUT) material for each size fraction. Oven set temperature: 571 ° C 5 U.S.

Screen Si Fe Cu Mn Mg + 2 "IN, 17, 41, 11, 90 1.19 OUT, 17, 41, 11, 91 1.23 10 - 2" +1 * 'IN, 17, 41, 11, 92 1.22 OUT, 18, 40, 10, 86 1.20 -1 "+1 / 2" IN, 16, 38, 10, 85 1.72 OUT, 16, 39, 11, 86 1.02 15 -1 / 2 ”+0.265" IN, 17, 41, 11, 91 1.19 OUT, 17, 40, 11, 92, 78 -0.265 "+4 IN, 21, 41, 12 1.00, 73 OUT, 24, 42, 12 1.01, 78 -4 + 7 20 IN, 37, 45, 14 1.06, 35 OUT, 26, 45, 13 1.05, 68 -7 + 10 IN, 24, 44, 13 1, 06, 26 OUT, 24, 48, 13 1.03, 54 -1 o1 oc IN - OUT -

Contained insufficient metal content for dosimeter analysis.

23 7? 266

Table III

Chemical analyzes of whole fractions leaving the oven at set temperature: 582 ° C

5 U.S.

Seoul Si Fe Cu Mn Mg +2 ", 17, 39, 11, 95, 96 -2" +1 ", 18, 39, 10, 91 1.05 -1" +1/2 ", 17, 39, 11 .90 1.10 10 -1/2 "+ 0.265", 17, 39, 10, 87 1.03 -0.265 "+4, 22, 38, 10, 83 1.63 -4 + 7, 18, 36, 09, 73 2.08 -7 + 10, 17, 32, 07, 60 2.70 -10, 23, 32, 11, 55 1.54 1 5

Table IV

Chemical analyzes of the whole fractions leaving the oven at the set temperature: 593 ° C

20 U.S.

Seoul Si Fe Cu Mn Mg +2 ", 17, 41, 12, 94, 48 -2" +1 ", 18, 42, 12, 97, 66 -1" +1/2 ", 19, 42, 12, 98, 64 25 -1/2 "+0.265", 18, 41, 12, 94, 56 -0.265 "+4, 17, 35, 09, 73 1.36 -4 + 7, 15, 30, 19, 56 2.57 -7 + 10, 15, 29, 06, 46 2.15 -10X _____ 24 772 6 6

Table V

Chemical analyzes of the whole fractions leaving the oven at the set temperature: 604 ° C

5 U.S.

Seoul Si Fe Cu Mn Mg + 2 ", 19, 44, 13 1.05, 58 -2" +1 ", 18, 43, 12 1.02, 66 -1" +1/2 ", 18, 44, 12 1.03, 67 10 -1/2 "+0.265", 18, 43, 12 1.02, 57 -0.265 "+4, 21, 37, 10, 82 1.61 -4 + 7, 17, 30 .7, 52 2.97 -7 + 10, 18, 25, 05, 36 3.43 -10X, 50, 29, 07, 36 3.35 15

Table VI

Chemical analyzes of fractions resulting from further fractionation of minus 10 material leaving the furnace at a set temperature of 604 ° C 20 U.S. Pat.

Screen weight% Si Fe Cu Mn Mg -10 + 14 2.6, 15, 27, 04, 38 3.67 -14 + 18 1.9, 16, 28, 04, 38 3.82 -18 + 20 0 , 5, 21, 26, 04, 35 3.64 25 -20 + 25 0.4, 35, 21, 05, 33 3.74 -25X 1.8 x Contained insufficient metal content for dosimeter-20 analysis.

Il 25 7 7 2 6 6

Table VII

Analysis of minus 25 material leaving the oven at set temperature: 604 ° C

5% aluminum through the development of hydrogen 56.2%

Chemical analysis: AI 56.7%

Fe 1.74% 1Q Si 10.8%

Calculated SiC> 2 23.1%% magnetic material 1.87% X-ray diffraction: aluminum> 10% 15 quartz> 10%

MgO <10%

Unidentified <10%

20 Table VIII

Chemical analyzes of a whole canned experiment with hulls made of 3004 and bottoms of 5182 25

Base pieces Body parts

Si 0.10 0.19

Fe, 25, 40

Cu, 03, 14 30 Mn, 36 1.09

Mg 3.69, 7

Cr, 02, 01

Ni, 00, 00

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Although the invention has been described in terms of preferred embodiments, the appended claims are intended to encompass other embodiments that fall within the scope of the invention.

Claims (10)

A method of securing such metallic components made of various types of plastic-lined aluminum alloys, the method comprising, as a first step, the acquisition of a charge containing at least two component types containing various types of plastic shaped aluminum alloys having different fusing melt temperatures, the process characterized in that it further comprises the following steps: (b) annealing the coating to a temperature sufficient to initiate an initial melting of the component which has the lowest initial melt temperature by thus increasing the fracture sensitivity of the at least one of said components to a level sufficient to cause decay in fragments of at least one of said components upon stirring of the annealed charge; (c) subjecting said heated charge to stirring sufficient to cause decomposition of said component having the lowest initial melt temperature; and (d) separating said fragmented components from the residual charge. 2. A method according to claim 1, characterized in that the charge provided in step (a) contains aluminum container bases and aluminum container bases, wherein the bottoms and bases are made of various kinds of plastic-shaped aluminum alloys, wherein said ends are defeated and recovered from the said frames. 3. A method according to claim 1 or 2, characterized in that a batch consisting of used food and beverage containers is used, the method preferably including the sorting of the batch before the heating to remove contaminated material. such as glass and shelf jars, and that it preferably also includes processing the dispatch for removal of varnish, decorative and protective coatings. 4. A method according to any of the preceding claims, characterized in that the charge is subjected to a drumming effect to cause the component, which has the lowest initial melting temperature, to disintegrate into fragments. Method according to any of the preceding claims, characterized in that the batch contains one or more types of containers which have a body part of the aluminum alloy AA3003, AA5042, AA3004, AA3104 or AA5052, and bottoms made of the aluminum alloy AA5182, AA5082, AA5052 or AA5042, and that the loading, if desired, also includes containers with frames and lids made of plaque having the composition 0.1-1.0 weight percent. % Si, 0.01-0.9 wt% Fe, 0.05-0.4 wt% Cu, 0.4-1.0 wt% Mn, 1.3-2.5 wt% Mg and 0-0.2% by weight of Ti, the residue being aluminum and temporary impurities. Process according to any of the preceding claims, characterized in that annealing gas is controlled in step (b) to prevent substantial melting of the component with the lowest initial melting temperature. Process according to any of the preceding claims, characterized in that the batch is annealed to a temperature in the range of either (i) 482-624 ° C; (ii) 538-624 ° C, preferably for a time from 15 seconds to several minutes; (iii) 581-624 ° C; (iv) 581-604 ° C, preferably for a time of about 30 seconds to 15 minutes; or (v) 581-649 ° C.