MXPA99007262A - Metal recovery from salt cake and other compositions - Google Patents

Abstract

A method for recovering aluminum metal from varied size clumps of salt cake. The salt cake clumps have varied concentrations of aluminum metal. The method includes steps of segregating (14) the varied size clumps into smaller clumps and larger clumps, by size;separating (22), by aluminum metal concentration, the larger clumps into clumps of higher aluminum metal concentration and reject clumps of lower aluminum metal concentration;impacting (24) the reject clumps to size-reduce the clumps to smaller reject clumps;returning the smaller reject clumps after impacting to the previous step of segregating;segregating (20) the smaller clumps from the step of segregating into large clumps and small clumps, by size;separation (28), by aluminum metal concentration, the small clumps into clumps of higher aluminum metal concentration and second reject clumps of lower aluminum metal concentration;and separating (30) the second reject clumps into clumps of higher and lower aluminum concentration.

Description

RECOVERY OF METAL FROM SALT CAKE AND OTHER COMPOSITIONS BACKGROUND OF THE INVENTION The present invention relates to systems and methods for recovering metal from salt cake and similar compositions and, more particularly, relates to systems and methods employing graduated eddy current separators to recover product. which has significantly elevated metal concentrations, from salt cake or similar material. The salt cake is obtained when the metal scrap is remelted, such as aluminum scrap or slag. When the aluminum or the aluminum-bearing materials are remelted, a flow is employed which includes a mixture of salt, mainly potassium chloride and sodium chloride, and a fluoride compound, typically cryolite. The flow is used to remove the impurities from the remelted waste, to reduce the oxidation of the metal and to improve the separation of the metal from the non-metal constituents. When the remelting furnace is bled, after the remelting process, the pure (ie, refined) metal is obtained as a product. A secondary product of the process that is also obtained is the salt cake.

The salt cake includes the flow, impurities that were contained in the metal, metal oxides, and leftover metal residues that were not separated as a pure metal product through the remelting process. The metal residues remain in the salt cake because they do not melt into larger pieces of metal during the remelting process. The larger metal pieces are removed as a product, but the residues do not separate from the salt cake. In cases where aluminum is the metal that was recovered, the salt cake, including the aluminum residues trapped in the salt cake, is typically disposed of as waste, for example, by throwing it into an embankment. . The different techniques for separating the aluminum from the salt cake are conventional. One of these techniques employs crushing and screening to separate the aluminum from the ^ Non-aluminum particles of salt cake. Sometimes different crushing and screening stages have been used. In the case of the different stages, the screening in each successive stage removes smaller particles than those that were removed in the previous stage. A significant disadvantage of the technique is that it does not remove much of the aluminum in the salt cake and, instead of this, it is thrown into embankments with the salt cake. In another technique, the raw material is ground and then ground to smaller particles. The milling serves to flatten the aluminum particles of the raw material. The particles are then screened at different stages of sieves of different sizes, to remove the particles of the raw material in accordance with the size. The larger particles that were removed have a higher concentration of aluminum. A significant disadvantage of the technique, however, is that the process is expensive. In addition, the non-metallic material that results is so fine, that it is dusty and difficult to handle in other ways in an embankment. d ^ Another conventional technique for removing aluminum from The salt cake dissolves the cake salt, releasing aluminum and other non-soluble particles by the same. In this technique, first crush and grind the salt cake. Then water is added to dissolve the salt. The solution is sieved with moisture, to recover the aluminum and other particles not soluble. The disadvantages of the technique, however, include ^ P that the salt cake is moistened, causing the oxidation of some of the remaining aluminum, a non-metallic, wet by-product that must be removed by filtering, and the salt solution that must be discarded or from which it must be recovered the salts, for example, by an additional process such as evaporative crystallization. further, the process includes a significant consumption of energy and operation and capital costs are high. In this way, what is needed is a method for the recovery of aluminum from salt cake and a system for carrying out this method, which overcomes the disadvantages and problems of the previous techniques and systems. SUMMARY OF THE INVENTION The embodiments of the present invention, in accordance with the foregoing, provide methods and systems for the recovery of aluminum metal from salt cake. Processes and systems provide advantages of increased recoveries of aluminum metal, desirable economies, efficient operations or byproducts, and others. For this purpose, one embodiment of the invention is a method for recovering the aluminum metal from clods of various sizes of salt cake. Clods of varying size contain varying concentrations of aluminum metal. The method includes the steps of first segregating the clods of varying size into clods plus sticks and larger clods, by size, first separating the larger clods into first lumps of high concentrations of aluminum metal and first lumps of waste, by concentrating of aluminum metal, which impacts the first lumps of waste, returning the first lumps of waste from the impaction step to the first segregation step, secondly, segregating the smaller lumps into small lumps and the smaller lumps, by size, secondly, separating the lumps stick in second lumps of high concentration of aluminum metal and second lumps of waste, by concentrating the aluminum metal, and third, separating the second lumps of waste in third lumps of high concentration of aluminum metal and third lumps of after erdicio, by concentrating the aluminum metal. Another embodiment of the invention is a method for recovering the aluminum metal from clods of varying size of salt cake. Clods of varying size contain varying concentrations of aluminum metal. The method includes a step of separating clods into high concentration lumps of aluminum metal and lumps of low concentration of aluminum metal. Still another embodiment of the invention is a system for recovering aluminum metal from clods of varying size of salt cake. Clods of varying size contain varying concentrations of aluminum metal. The system includes means for first segregating the clods of varying size into smaller clods and larger clods, by size, means for first separating the larger clods into first lumps of high concentration of aluminum metal and first lumps of waste, by concentration of the aluminum metal, means to impact the first lumps of waste, means to return the first lumps of waste from the means to impact the means to segregate first, means to segregate the lumps secondly into small lumps and secondly smaller lumps, by size, means for separating secondly the small lumps e-lumps of high concentration of aluminum metal and second lumps of waste, by the concentration of the aluminum metal, and means for separating the second lumps in third of waste in third-party clods of high concentration of Such aluminum and third lumps of waste, by concentrating the aluminum metal. Another embodiment of the invention is a system for recovering aluminum metal from lumps of various sizes of salt cake. Clods of varying size contain varying concentrations of aluminum metal. The system includes means for separating lumps into high concentration lumps of aluminum metal and lumps of low concentration of aluminum metal. Still another embodiment of the invention, is a system for magnetic separation. The system includes a drum that has a circumference, a circular band that is connected to the circumference of the drum, the circular band runs along the circumference of the drum and the drum is located within the circular band, a rotor is also connected of discharge to the circular band, the circular band runs along the circumference of the discharge rotor and the discharge rotor is located within the circular band, a distributor guide that is operatively connected to the discharge rotor, and a distributor that connects to the distributor guide to slide the coupling and select the assurance with the distributor guide. Another embodiment of the invention is a method for recovering a product which has a significant concentration of a metal from compositions in lumps of varying size of metal and other matter. Chipped compositions of varying size contain varying amounts of the metal. The method includes the steps of impacting the compositions in clods of varying size, to obtain lumps reduced in size and swirl current that separates the lumps reduced in size into lumps reduced in size of the significant concentration and lumps reduced in size of less than significant concentration. Yet another embodiment of the invention is a system for recovering a product having a significant concentration of a metal from compositions in clods of varying size of metal and other matter. Chipped compositions of varying size contain varying amounts of the metal. The system includes the steps of impacting the compositions in clods of varying size, to obtain lumps reduced in size and means, which are operatively connected to the means to impact, for the swirling current that separates the clods reduced in size into clods reduced in size of significant concentration and lumps reduced in size of less than significant concentration. A further embodiment of the invention is a system for recovering a product having a significant concentration of a metal from compositions in lumps of varying size of metal and other matter. Chipped compositions of varying size contain varying amounts of the metal. The system includes an impact primer to shred the compositions into clods of varying size, to obtain lumps reduced in size and a swirl current separator, which is operatively connected to the impact printer, to separate the clods reduced in size in lumps reduced in size by significant concentration and lumps reduced in size by less than significant concentration. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flowchart of a process for recovering aluminum metal from salt cake, in accordance with the embodiments of the present invention. Figure 2 is a simplified representation of a plant for the recovery of aluminum metal from salt cake, which performs the process shown in Figure 1, in accordance with the embodiments of the present invention. Figure 3 is a simplified, elevational side view of a discharge rotor of a swirl current separator, having a manifold that can be variably positioned with respect to the discharge rotor within a path region of the separator, in accordance with the embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Method for Recovering Aluminum Metal from Salt Cake: With reference to Figure 1, a method 10 for recovering aluminum metal from salt cake is initiated by a step 12. In step 12, the salt cake containing aluminum metal is hammered such as the salt cake that is recovered from the slag in a conventional oven heating operation, to break the lumps of salt cake containing the aluminum metal , in smaller pieces. A conventional pneumatic gun or any other hammering device may be used, for example, for step 12. After step 12, the pieces that were obtained from breaking the clods in a step 14 are selected to separate the metal pieces. of aluminum larger than the other pieces. Step 14 can be performed, for example, as a manual selection by a human, to remove pieces that are judged too large or problematic in any other way, for further crushing. Those larger aluminum metal pieces which were separated in that way in step 14, are retained as the aluminum metal of the product and are sent to an oven for the recovery of the metal.

In a step 16, all parts that are not retained in step 14, are impacted to crush the pieces into smaller shredded pieces. Step 16 is performed, for example, by shredding the pieces by impact using an impact printer, such as a conventional impact crusher. The shredded pieces from step 16 are magnetically separated into relatively high magnetic attracted pieces, such as those pieces having a high iron content, and other pieces broken into a step 17. Step 17 is performed by a device of magnet, for example, a magnetic head pulley. The relatively high magnetically attracted parts adhere to the magnet device and are removed by the same from the other crushed pieces, in view of the fact that the other crushed pieces do not adhere. Crushed pieces that do not adhere to the magnet device are separated by grate in a step 18. Step 18 is performed by shaking the shredded pieces from step 16, on a frame with slightly inclined iron bars, such as a frame. with iron bars that are formed of a series of equally spaced bars, which are longitudinal along the inclination. The larger crushed pieces remain on the frame with iron bars and pass along the inclination until they fall from above the frame with iron bars, and the other crushed pieces pass between the bars of the frame with iron bars. The larger crushed pieces that pass along the inclination and that fall from above the frame with iron bars, are selected manually in fractions of high concentration of aluminum metal and low concentration of aluminum metal. The determination of the high concentration against the low concentration of aluminum metal is made by the human revision of the pieces, to detect the approximate metal content. The pieces of high concentration of aluminum metal are lifted from the other pieces and returned to the conventional furnace for the recovery of the metal. The operation of the furnace can produce additional salt cake containing aluminum metal, which can be processed by method 10. The low concentration fraction of aluminum metal is returned to the impact primer. In one step 20The shredded pieces that pass between the bars of the iron bar frame are sifted on a double platform. The step 20 of double platform screening includes a first screening to separate the shredded pieces into larger pieces and smaller pieces. A first sifter is used, which, for example, is a conventional sifter that is placed at an incline, in the first screening step 20. The larger pieces remain on top of the first sifter, and the smaller pieces pass through the first sifter. The step 20 of double-platform screening also includes a second screening to segregate the largest and smallest of the pieces that pass through the first sifter. A second sifter is used, which, for example, is also a conventional sifter that is placed at an incline, in the second screening of step 20. The second sifter has a smaller aperture size than the first sifter. In the second screening, the larger pieces between the pieces that passed through the first sieve on the first screening, remain on top of the second sieve, and the smallest of those pieces pass through the second sieve. In a step 22, the larger pieces which do not pass through the first sifter in step 20 are removed by swirl current, in pieces having a significant concentration of aluminum metal and pieces having a lower concentration of the aluminum. It is intended that the term "significant" as used herein with respect to the concentration of aluminum metal, indicate a particular limit value of the aluminum metal concentration, which is sought as the aluminum metal of the product that was obtained from method 10. Of course, the significant concentration of aluminum metal desired for the product of method 10 in any case, may change in accordance with the desired results of method 10. In each case, the concentration value Significant aluminum metal should be within the range of concentration values that can be obtained, in fact, from method 10. Sometimes in the present, the term "aluminum concentration" can be used.; it is intended that this term refers to the concentration of aluminum metal only and not to other forms of aluminum. In the swirl current separation of step 22, a conventional eddy current separator creates magnetic forces. In the swirl current separator, the magnetic forces that are created in this manner, repel the parts that have the significant concentration of aluminum metal from the parts that have the lowest concentration of aluminum metal. Parts that have the lowest concentration of aluminum metal are repelled to a lesser degree than those that have significant metal concentration. When a manifold, such as a sheet of metal, is selectively placed within the path passage of the parts that were repelled by the eddy current separator, the pieces that repel most of the way pass over the distributor, while that the other parts do not pass over the distributor. The repellent force, by virtue of and in cooperation with the selective placement of the distributor, therefore, separates the parts that have the significant concentration of aluminum metal from the parts that have the lowest concentration of aluminum metal. The repelling pieces having the significant concentration of aluminum metal of step 22 of method 10 are retained in step 15. These pieces having the significant concentration of aluminum metal are also the aluminum metal of the product which was obtained at from the method 10. The pieces having the lowest concentration of aluminum metal, which were obtained from the swirl current separation of step 22, are further impacted in a step 24. Step 24 shreds the pieces that have the lowest concentration of aluminum metal, to reduce them in size. The shredded pieces of step 24 are returned to step 20 and again screened on double platform in step 20. Method 10 continues thereafter with respect to those pieces shredded from step 20 as just described. The return of the shredded pieces from step 24 to the double platform screening of step 20, performs a feedback to achieve a desired concentration of aluminum metal in the aluminum metal of the product that was obtained from method 10 and also recovers the metal of additional aluminum from the pieces that were rejected first in step 22. In a step 28, the pieces that pass through the first sieve in the first sieve are separated by swirl current, but not through the second sieve in the second screening of step 20. As with the swirl current separation of step 22, the parts having the significant concentration of aluminum metal are repelled and the parts having the lowest concentration of aluminum metal are not repelled in a manner so big. This separates the parts that have the significant concentration of aluminum metal from the parts that have the lowest concentration of aluminum metal. From step 28, the parts having the significant concentration of aluminum metal are retained from method 10 in step 15. These parts having the significant concentration of aluminum metal are also the aluminum metal of the product that is obtained from method 10. Parts that have the lowest concentration of ^^ aluminum metal in step 28 are further separated by swirl current in a step 30. In step 30, those parts of step 28 are further separated into pieces having the significant concentration of aluminum metal and parts that do not have the significant concentration of aluminum metal. The concentrations of aluminum metal that are significant in step 30, are less than the concentrations ^ P of aluminum metal which are significant in step 28. Step 30, therefore, makes a "deeper cut" of the pieces than step 28, producing a larger quantity of the pieces that has the significant concentration of aluminum metal that separate in step 30. These pieces having the significant concentration of aluminum metal are, however, of a lesser degree because they are of a lower aluminum metal concentration than the pieces that were retained from the swirl current separation. from step 28. The pieces that have the significant concentration of aluminum metal as separated in step 30, from method 10 in step 15. These pieces having the significant concentration of aluminum metal are also the aluminum metal of the product which was obtained from the Method 10. System for Recovering Aluminum Metal from Salt Cake: With reference to Figure 2, a system 100, such as a processing plant, for recovering the aluminum metal from salt cake in accordance with Method 10 of Figure 1 includes a first equalizer hopper 102. The first equalizer hopper 102 is a conventional hopper of the type that includes a storage tank portion and a portion of the exit feeder. The outlet feeder portion includes a regulator, such as an orifice of variable size, to selectively output the contents of the first equalizing hopper 102. The portion of the storage container serves to contain the salt cake containing the aluminum metal, which salt cake has been recovered, for example, from the heating of the slag in the conventional oven heating operation and is loaded into the storage tank portion. The portion of the outlet feeder serves to selectively output the salt cake that was loaded into the portion of the storage tank, in order to control the feed rate of the salt cake contained in the first hopper. equalizer 102, for processing by system 100. The first equalizer hopper 102 is, for example, a sixty-eight (68) tonne equalizing hopper. The salt cake is output by the first equalizing hopper 102, on a feeder 104. The feeder 104 is operatively connected to the first equalizing hopper 102, to receive the salt cake which was thus discharged. . The feeder 104 includes a conveyor and a measuring instrument. The conveyor 104 transports the salt cake, and the measuring instrument measures the weight of the salt cake that is transported in that way. The feeder 104 is, for example, a metering conveyor (i.e., a conveyor equipped to measure the materials being transported) or another transport and conventional measuring device or devices. In one example, the feeder 104 measures 50"x20" and can transport and measure at least 50 +/- tons per hour. A first impact crusher 106 is operatively connected to the feeder 104 to receive the salt cake from the feeder 104. The first impact crusher 106 can crush blocks that are from about 2 feet to about 3 square feet to particles reduced in size , which are about 3 square inches or less. The first impact crusher 106 is a conventional impact crusher, for example a 300 HP impact crusher. A first conveyor 108 transports the reduced particles from the first impact crusher 106. A second equalizing hopper 110 is operatively connected to the first conveyor 108., to receive the reduced particles from the first conveyor 108. The second equalizing hopper 110 contains the reduced particles. The second equalizing hopper 110 is substantially similar to the first equalizing hopper 102, both in design and function. The second equalizing hopper 110 is, for example, an equalizing hopper of twenty-five (25) tons. The second equalizing hopper 110 gives output selectively to the small particles contained therein. The particles reduced in this way by the second equalizing hopper 110 are output to a grid feeder 112 which is operatively connected to the second hopper. equalizer 110 to receive the reduced particles. He ^ P grid feeder 112 is a frame with generally flat iron bars having parallel bars spaced apart erectly through the frame with iron bars. The grate feeder 112 is positioned in an inclined manner, in a manner that the parallel bars extend longitudinally in the direction of inclination. An inclination angle α of the grill feeder 112 is sufficient to cause the size-reduced particles to progress along the inclination at a suitable speed. The bars are separated parallel of the grid feeder 112, for example, about 3 inches apart to prevent the reduced particles, which are larger than about 3 square inches, from passing through the frame with iron bars. The grill feeder 112, for example, measures 42"xl7" 5 and passes to at least about 28.21 tons per hour. Particles that do not pass through the grill feeder 1122 are held within a reservoir 114 that is operatively connected to the grill feeder 112, such as a conventional concrete tank or other reservoir. The content of the reservoir 114 are periodically discharged to the conventional oven heating operation. A second conveyor 116 that is operatively connected to the grid feeder 112 receives and transports the particles passing through the grid feeder 112. 15 A double sifter 118 is operatively connected ^ P platform to the second conveyor 116, to receive the particles from the conveyor 116. The double-platform sieve 118 includes a first sieve 118a and a second sieve 118b. The first sieve 118a and the second sieve 118b are placed parallel to each other and in an inclined manner. An angle ß of inclination of the first and second sifter 118a and 118b of the double platform sifter 118 is sufficient to cause the reduced particles to progress along the slope at a suitable speed. The first 118a sifter has a mesh size, eg, 1/2 inch square, to prevent particles that are larger than about 1/2 square inch from passing through the first sieve 118a. The second sifter 118b has a smaller mesh size than the first sifter 118a, for example, the second sifter 118b is a # 10 mesh sifter. The first and second finders 118a and 118b each measure approximately 4'xl2"in one example The first and second finders 118a and 118b are operatively connected, so that the particles passing through the first sieve 118a are deposited directly the first sifter 118a above the second sifter 118b The double platform sifter 118 also includes a collector 118c, such as a generally funnel-shaped tank with an outlet orifice, which is operatively connected to the second sifter 118b, for collecting and pouring the particles passing through the second sifter 118b A first swirl current separator 120 is operatively connected to the first sifter 118a to receive the particles that do not pass through the first sifter 118a. Swirl current can make swirl current separations of the particles in amounts of up to at least about 9.32 tons per hour. The first eddy current separator 120 is available for example, with Hurin Valley Steel of Belleville, Michigan, Model Mark IV-48. A third conveyor 122 is operatively connected to the first swirl current separator 120, to receive the particles having less than the significant concentration of aluminum metal from the operation of the first swirl current separator 120. A second impact crusher 126 is operatively connected to the third conveyor 122, to receive the particles from the third conveyor 122. The second impact crusher 126 is, for example, a Stedman Model GS3030 impact crusher, available from Stedman Machine Co . , from Aurora, Indiana. The second impact crusher 126 can reduce the sizes of the particles, such as to less than about 1/2 square inch. The second impact crusher 126 is also operatively connected to the second conveyor 116, so that the second conveyor 116 receives the crushed particles from the second impact crusher 126 and transports them to the double platform sieve 118. A second swirl current separator 127 is operatively connected to the double platform skimmer 118 to receive particles passing through the first skimmer 118a, but not through the second skimmer 118b. The second eddy current separator 127 is substantially identical to the first eddy current separator 120, for example, the second eddy current separator 127 is available from Huron Valley Steel of Belleville, Michigan, Model Mark IV-48. A fourth conveyor 128 is operatively connected to the second eddy current separator 127 to receive the particles having less than the significant concentration of aluminum metal from the operation of the second eddy current separator 127. A third eddy current separator 130 is operatively connected to the fourth conveyor 128 to receive the particles that are transported therethrough. The third eddy current separator 130 is substantially identical to the first and second eddy current separators 120 and 127, for example, the third eddy current separator 130 is available from Huron Valley Steel of Belleville, Michigan, Model Mark. IV-48. A fifth conveyor 132 is operatively connected to the collector 118c of the double-deck sieve 118 to receive the collected particles that were collected by the collector 118c. A sixth conveyor 134 is operatively connected to each of the first, second and third eddy current separators 120, 127 and 130 to receive the particles having the significant concentration of aluminum metal that was obtained from the respective eddy current separation operations. The sixth conveyor 134 serves to transport the particles having the significant concentration of aluminum metal to the storage 136. A seventh conveyor 138 is operatively connected to the fifth conveyor 132 to receive the particles that were transported by the fifth conveyor 132 and the third separator. 130 of swirl current, to receive the particles having less than the significant concentration of aluminum metal from the operation of the third swirl current separator 130. The seventh conveyor 138 is also operatively connected to an eighth conveyor 140 for receiving the particles from the seventh conveyor ^^ 138. A construction 142 of storage to the eighth conveyor 140 for receiving the particles from the eighth conveyor 140. A ninth conveyor 144 is operatively connected to the storage construction 142 for receiving the particles from the storage construction 142. The ninth transporter 144 is connected to the equipment of load 146, which serves to receive the particles from the ^ P ninth transporter 144. The loading equipment 146 allows loading the vehicles that transport the particles to be disposed of in embankments. The conveyors 108, 116, 122, 128, 132, 134, 138, 140 and 144, the storage construction 142, and the loading equipment 146 are conventional types known to those skilled in the art. With reference to Figure 3, the third eddy current separator 130 is eguipated with a distributor 150. The eddy current separator 130 also includes a drum 154 and a band 156, as is conventional. The distributor 150 can be positioned in a variable manner with respect to the discharge rotor 152 of the third eddy current separator 130. The distributor 150 is attached to a guide (not shown) for movement of the distributor along the guide, to vary the position of the distributor 150 with respect to the discharge rotor 152. The distributor 150 can be secured to the guide when it is located as desired, for example, by means of bolts. The positioning of the distributor 150 with respect to the discharge rotor 152 serves to desirably segregate the particles 158 leaving the band 156 in the discharge rotor 152. The particles leaving the distributor 150 are discharged onto a path zone x. , because the particles 158 of any particular aluminum metal composition are repelled, more or less, by the magnetic effects of the discharge rotor 152 than the particles 158 of different aluminum metal composition. As described above, the particles 158 having higher concentrations of the aluminum metal are repelled more than the particles 158 having lower concentrations of the aluminum metal. The repellent force causes the dispersion of the particles 158 through the entire path area x, in accordance with the concentration of aluminum metal of the particles 158 with respect to other of the particles 158. The dispersion is in the nature of a gradient of concentrations of the particles 158, so that the particles 158 having the highest concentration of aluminum metal are dispersed to a first region a of the path zone furthest away from the discharge rotor 152, the particles 158 are dispersed having the lowest concentration of aluminum metal to a second region b of the path zone x closest to the discharge rotor 152, and dispersion of the particles 158 occurs between the first region a and the second region b, in accordance with the highest and lowest aluminum metal concentrations. As will be understood by those skilled in the art, by varying the position of the distributor 150 a z-path zone is formed for the particles 158 having the significant concentration of aluminum metal, and a path zone and for the particles 158 having less than the significant concentration of aluminum metal. In this way, a desired "cut" of the particles 158 is achieved to segregate the particles 158 which have the significant concentration of aluminum metal from the other of the particles 158. With reference to Figures 1, 2, and 3, in FIG. set, in the operation of the system 100, is hammered with a pneumatic gun, the salt cake is selected and charged, including the aluminum metal that has been recovered from the heating of the slag in the heating operation by a conventional oven, within the first equalizer hopper 102. The first equalizing hopper 102 is controlled to deposit adequate amounts of salt cake on the feeder 104., for example, approximately 50 tons per hour of salt cake. The feeder 104 passes the salt cake, after the salt cake was cooled, to the first impact crusher 106. The first impact crusher 106 has a 1 ° separation assembly, of 6-8 inches, 2 ° , of -4 inches. In this way, the first impact crusher 106 crushes the salt cake to produce pieces of approximately 3 square inches. The first impact crusher 106 passes the pieces of the salt cake to the first conveyor 108. The first conveyor 108 transports the pieces of the salt cake to pass under a magnet 109, for example, a magnetic head pulley. The pieces of the salt cake which have the highest concentrations of the magnetically attractive metals are attracted to and retained by the magnet 109. The pieces of the salt cake which are not retained in the magnet 109, after passing under the magnet 109, they are released by the first conveyor 108 to the second equalizing hopper 110. The pieces of the salt cake which are released in this manner are loaded into the second equalizing hopper 110. The second equalizing hopper 110 is controlled. for depositing the right quantities of pieces of the salt cake on the grill feeder 112, for example, approximately 28.31 tons per hour. Pieces of the salt cake that are no larger than about 3 square inches pass through the grill feeder 112, for example, at a rate of approximately 28.21 tons per hour. The larger pieces of the salt cake remain on top of the grill feeder 112. The larger pieces above the grill feeder 112 slide downward from the grill feeder 112 within the concrete tank 114. The larger pieces of concrete tank 114 are removed and returned to the kiln operation. The pieces of the salt cake that were passed through the grill feeder 112 are placed on the conveyor A 116. The conveyor 116 transports the pieces of the salt cake to the double platform sieve 118. The pieces of the salt cake are placed on top of the first sieve 118a. Pieces of the salt cake that are no larger than about 1/2"square, pass through the first sieve 118a. the largest salt cake, remain on top of the first ^ P sieve 118a. The pieces above the first sieve 118a slide down the first sieve on the first swirl current separator 120, for example, at a speed of approximately 9.32 tons per hour. The assemblies of the first swirl current separator 120 are, for example: syntron feeder speed of approximately 20.3 tons per hour; band speed of approximately 400 feet per minute; and rotor speed of approximately 565 rpm. Based on the example assemblies and the speed of passage of the salt cake to the first swirl current separator 120 from above the first sifter 118a, the product particles having the significant concentration of aluminum metal are obtained (to the which is referred to as "concentrated"). The other particles which do not have the significant concentration of aluminum metal (referred to as "waste"), are accommodated in the third conveyor 122. The third conveyor 122 transports the waste to the second impact crusher 126. The Second Impact Crusher 122 has a 1 °, 2.5 inch, 2 °, 0.5 inch separation assembly. The second impact crusher 106, thereby shreds the debris from the first swirl current separator 120 into pieces approximately 1/2 inch square and smaller. The second impact shredder 122 passes the shredded waste to the second conveyor 116, where the shredded waste is combined with the pieces of the salt cake from the grill feeder 112. In this way, the third conveyor 122 and the second impact crusher 126 form a feedback loop for debris from the first eddy current separator 120. The pieces of the salt cake that pass through the first sieve 118a are placed on top of the second sieve 118b, for example, a # 10 mesh sieve. Pieces of the salt cake that do not pass through the second sieve 118b remain on top of the second sieve 118b. The pieces on the second sieve 118b slide down from the second sieve 118b to the second swirl current separator 127. Mounts of the second eddy current separator 127 are, for example, web speed of approximately 400 feet per minute and rotor speed of approximately 550 rpm. The concentrate is obtained from the second eddy current separator 127 and passed to the sixth conveyor 134. The waste from the second eddy current separator 127 is placed in the fourth conveyor 128. The fourth conveyor passes said waste to the third separator 130. of swirling current. The assemblies of the third eddy current separator 130 are, for example: web speed of approximately 400 feet per minute and rotor speed of approximately 575 rpm. The concentrate and debris are available from the third eddy current separator 130. The concentrate is passed to the sixth conveyor 134, and the waste is passed to the seventh conveyor 138. The concentrate obtained from each of the first, second, and third separators 120, 127, and 130 of eddy current is placed in the container. sixth conveyor 134. The sixth conveyor 134 transports the concentrate to storage 136. The particles of the salt cake which pass through the second sieve 118b of the double-deck sieve 118 as waste are treated and placed on the fifth conveyor 132. fifth conveyor 132 transports the waste to the seventh conveyor 138. The waste of the third eddy current separator 130 is also accommodated in the seventh conveyor 138. The seventh conveyor 138 passes the waste to the eighth conveyor 140. The eighth conveyor 140 deposits the waste at the storage construction. Waste is removed, from time to time, of the storage construction 142. When removed in this manner, the waste is placed on the ninth conveyor 144 and transported to the loading equipment 146. The loading equipment 146 loads the waste into the transport vehicles. The transport vehicles drag the waste to be disposed of, for example, in an embankment. Below are different examples of the modalities: EXAMPLE 1 - Run 93 First, the salt cake was manually selected in the amount of 632,140 pounds, to remove large pieces of metal or other components resistant to crushing. The remaining salt cake was then passed through an impact crusher which is adjusted to crush the salt cake to approximately 3 inches or less in the maximum dimension. The resulting material was passed over a grate to remove larger pieces of 3 inches in maximum size. The material that passed through the grill was passed over a sieve with 1/2 inch openings. The material that did not pass through the sieve was sent to the swirl current separator (ECS) Number 1, which had its distributor, band speed, and rotor speed, adjusted to recover the pieces that contained a high content of aluminum metal. The speed of the band was 333 feet per minute, the rotor speed was 565 rpm. The total processing speed was 26.9 tph. For example, the interval between the bottom side of the concentrate path (high degree) and the top of the path of the waste material (lower grade) was about 1 inch or more. In total, the eddy current separator receives a material flow and divides it into 2 products, one called concentrate, and the other waste. The concentrate results mainly from the magnetic forces created by the eddy current separator and contains a higher metal content than either the material or the waste. The waste is what remains of the material, after the concentrate was extracted. The attempt with the ECS Number 1 was to recover those larger pieces that were mostly made of aluminum metal and to reject those that were either too low in aluminum metal or had a significant non-aluminum metal content.

The waste of the ECS Number 1 was sent to a secondary impact crusher, with the aim of reducing the particle size to less than 1/2 inch. The shredded material was then sent to the 1/2 inch sifter that was previously cited. In this way, a recycling circuit was established to facilitate the reduction of waste size of the ECS Number 1, with the aim of releasing more aluminum particles that are in combination stacked with the material without metal. The material that passed through the sieve was passed 1/2 inch over a sieve with mesh openings 10. The material that passed through the sieve was sent to an embankment. The material that did not pass through the 10 mesh screen was sent to the ECS Number 2. The band speed was 436 feet per minute and the rotor speed was 552 rpm. In this case, the interval between the lower side of the concentrate path (high degree) and the upper part of the waste material path (lower degree) was about 1/2 inch or more. As with ECS Number 1, the attempt was to recover a high grade concentrate, preferably instead of extracting the maximum amount of aluminum metal from the ECS material. Waste from ECS Number 2 was sent to ECS Number 3, which had a belt speed of 365 feet per minute and a rotor speed of 575 rpm. The concentrate that resulted from ECS Number 3 was a lower grade concentrate than that from ECS Number 1 and ECS Number 2. Specifically, '^ _ with the distributor position and rotor speed that were held constant, was adjusted the speed of the band in the ECS Number 3 at the speed of 575 rpm, so as to cause the distributor to be slightly above the upper edge of the range of the trajectories of the waste. In this way, relatively rich material in aluminum metal was poured from the leading edge of the waste trajectories. The waste from ECS Number 3 was sent to the embankment. The concentrate of all the ECS units was combined and processed in a rotary kiln to recover the aluminum metal. A total of 632,140 pounds of salt cake was processed, resulting in 39,200 pounds of concentrate. The concentrate, when further processed in the rotary kiln, produced 15,200 pounds of aluminum metal. In this run, the weight of the concentrate that was collected was 6.20 percent of the initial salt cake and the final metal that was collected was 2.4 percent of the initial salt cake. Furnace recovery, which is defined as the percentage of metal recovered from the concentrate in an oven, was 38.78 percent. The salt cake that was produced by oven operations in the concentrate was returned to the salt cake treatment plant for further recovery. EXAMPLE 2 - Run 217 In this run, all assemblies were adjusted to increase the amount of concentrate in relation to the amount of waste. The processing speed was 46.0 tph. The belt and rotor speeds for the ECS units were as follows: Rotor Speed Band Speed (rpm) (fpm) ECS # 1 568 339-340 ECS # 2 553 448 ECS # 3 576 357-359 As a result, the distributor cut deeper the range of the trajectories of the waste, segregating by the same a larger amount of particles of the lowest concentration of aluminum metal in the concentrate. A total of 5,286,760 pounds of salt cake was processed, which resulted in 538,360 pounds of concentrate. The concentrate, when further processed in a rotary kiln, produced 170,874 pounds of aluminum metal. In this run, the weight of the concentrate that was collected was 10.2 weight percent of the initial salt cake and the aluminum metal of the product that was collected was 3.23 weight percent of the initial salt cake. The recovery of the furnace was 31.74 percent. It is evident that having taken a larger percentage of the weight of the concentrate in this run, resulted in a lower furnace recovery. This indicates the recovery of a lesser degree of the concentrate. However, a higher metal recovery percentage was obtained than that obtained in Run 93. The lower degree of the concentrate was more than compensated by the larger amount of concentrate that was collected. EXAMPLE 3 - Run 223 In this run, all the assemblies were adjusted in order to increase the amount of concentrate in relation to the amount of waste. The processing speed was 39.6 tph. The belt and rotor speeds for the ECS units were as follows:y.

Rotor Speed Band Speed (rpm) (fpm) ECS # 1 565 333 ECS # 2 552 436 ECS # 3 575 365 In total, 4,735,860 pounds of salt cake were processed, which resulted in 670,440 pounds of concentrate. The concentrate, when further processed in a rotary kiln, produced 170,383 pounds of aluminum metal. In this run, the weight of the concentrate that was collected was 14.16 percent of the initial salt cake and the weight of the metal was collected was 3.60 percent of the initial salt cake. The recovery of the furnace was 25.41 percent. Again, it is evident that having taken a larger weight percentage of the concentrate in this run, further decreased the recovery of the furnace. This indicates that a lower degree, ie, reduced concentration of aluminum metal, was obtained from the concentrate in this run, but the run produced higher total recoveries of the aluminum metal than Runs 93 and 217. The lowest degree of the concentrate was more than compensated for the larger amount of concentrate that was collected. Different variations in the previous modalities are possible. For example, the distributors of each of the first swirl current separators 120, 127 and 130 may be positioned to obtain optimum or otherwise desirable concentrate results. Also, more or less eddy current separation steps could be used, for example, system 100 may include four or more stages. Additionally, the concentrate that was collected from the different steps could be handled separately, for example, the concentrate obtained from a particular whirlpool current separator could be heated in the furnace, under temperatures different from the of the furnace heating of the concentrate of another of the eddy current separators, in order to optimize the metal qualities of the product or other reasons. Of course, other variations are possible in the treatment of the concentrate that was recovered. Additional crushing steps and other operations are also possible. Numerous variations can be made in the equipment, for example, material feeds, screenings, and impactions could be performed by other equipment, such as contraction bags with valves, air tables, or U separators and gravity presses, respectively. Additionally, system 100 could be fully or up to a certain automatic degree by, for example, instrumentation and process controls, such as electrical, computerized, non-static hardware or other controls and instruments. Of course, the number of transporters could also be reduced or increased. res, storage units, hoppers, loaders, sieves, racks with iron bars, and impactors, for particular applications. In addition, in other variations, the method and system are used to recover other metals that have similar crushing, grading, filtering, and separation characteristics. swirl current, for example, magnesium metal. From In addition, the system and method for recovering aluminum metal from other metals other than slag can be employed. The slag can be any of a variety of wing substances that is generally referred to as slag. The scum can be white scoria or black scoria. As those skilled in the art will know and appreciate, white slag is the oxide film on top of the furnace process product, which film consists of metal particles and metal oxides, and the black slag is essentially slag. white that contains the salt that was added in the oven processing, with the objective of minimizing the oxidation of the process. Although the illustrative embodiments of the invention have been shown and described, a broad range of modifications, changes, and substitutions are contemplated in the foregoing description and, in some cases, some features of the present invention may be employed, without any use. corresponding to the other characteristics. In accordance with the foregoing, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.

Claims (21)

1. CLAIMS 1. A method to recover metallic aluminum from terrors of varied sizes of salt cake, the clods of varied sizes containing varied concentrations of metallic aluminum, which comprises the steps of: first segregation of clods of varying sizes in clods more smaller and larger clods, by size; first separation of the largest lumps in first lumps of high concentration of metallic aluminum and first rejected lumps, by concentration of metallic aluminum; impact the first rejected clods; return the first clods rejected from the impact step to the first segregate step; second segregation of the smaller clods into small clods and smaller clods, by size; second separation of the small lumps in second lumps of high concentration of metallic aluminum and second lumps rejected, by concentration of metallic aluminum; third separation of the second lumps rejected in third lumps of high concentration of metallic aluminum and third lumps rejected, by concentration of metallic aluminum.
2. 2. The method of claim 1, wherein the steps of first separation, second separation and third separation are each carried out by means of magnetic repulsion forces.
3. The method of claim 1, further comprising the steps of: hammering blocks to obtain unsorted pieces of salt cake; classify unclassified chunk heads into larger chunk heads and smaller chunk heads, by ^^ size; e 10 impact the smallest piece heads to obtain lumps of varying sizes of salt cake; Segregate the smaller lumps into clods of varying sizes and lumps of furnace.
4. 4. The method of claim 3, wherein the steps of first separation, second separation and third separation ^ P are each carried out by magnetic repulsion forces.
5. 5. A method for recovering metallic aluminum from clods of varying sizes of salt cake, the lumps of 20 varied sizes containing varying concentrations of metallic aluminum, comprising the step of separating the clods into high concentration lumps of metallic aluminum and lumps of low concentration of metallic aluminum.
6. 6. The method of claim 5, wherein the separation step is carried out by a parasitic current separator equipped with a divider.
7. The method of claim 6, further comprising the step of placing the divider in a path zone between the lumps of high concentration of metallic aluminum and the lumps of low concentration of metallic aluminum.
8. 8. A system for recovering metallic aluminum from clods of varying sizes of salt cake, the lumps of various sizes containing varying concentrations of metallic aluminum, comprising: means for the first segregation of lumps of varying sizes into smaller lumps and larger lumps, by size; means for the first separation of the largest lumps in first lumps of high concentration of metallic aluminum and rejected first lumps, by concentration of metallic aluminum; means to impact the first rejected clods; means to return the first clods rejected from the media to impact the media for the first segregation; means for the second segregation of the smaller clods into small clods and smaller clods, by size; means for the second separation of the small clods into second clods of high concentration of aluminum and second clods rejected, by concentration of metallic aluminum; and means for the third separation of the second lumps rejected in third lumps of high concentration of metallic aluminum and third lumps rejected, by concentration of metallic aluminum.
9. The system of claim 8, wherein the means for the first separation, the means for the second separation and the means for the third separation are each separate from parasitic current.
10. The system of claim 8, further comprising: means for hammering blocks to obtain unsorted lumps; means for classifying unsorted lumps into large lumps of high concentration of metallic aluminum and lumps of other size, by size; means to impact the lumps of another size to obtain lumps of smaller size; and means to segregate the smaller lumps into clods of varying sizes and lumps of furnace.
11. The system of claim 10, wherein the means for the first separation, the means for the second separation and the means for the third separation are each eddy current separators.
12. 12. A system for recovering metallic aluminum from lumps of various sizes of salt cake, the lumps of various sizes containing varying concentrations of metallic aluminum, comprising means for separating the 5 lumps in lumps of high concentration of metallic aluminum and lumps of low concentration of metallic aluminum.
13. The system of claim 12, wherein the means for separating is a parasitic current separator ^^ equipped with a divider.
14. 14. The system of claim 13, further comprising means for placing the divider in a path zone between the lumps of high concentration of metallic aluminum and lumps of low concentration of metallic aluminum.
15. 15. A system for magnetic separation, comprising: P a drum having a circumference; a circular band connected to the circumference of the drum, the circular band traveling along the circumference of the drum and the drum being located within the circular band 20; a discharge rotor also connected to the circular band, the circular band traveling along the circumference of the discharge rotor and the discharge rotor being located within the circular band; 25 a divider guide operatively connected to the discharge rotor; and a divider connected to the divider guide to slide the link and select the clamp with the divider guide.
16. 16. A method for recovering a product having a significant concentration of a metal from lump compositions of various sizes of metal and other matter, lump compositions of various sizes containing varying amounts of the metal, comprising the steps of: ^^ Impact compositions of lumps of sizes 10 varied to obtain lumps of reduced size; and to separate by means of parasitic current the lumps of reduced size in lumps of reduced size of significant concentration and lumps of reduced size of concentration less than significant.
17. 17. The method of claim 16, containing ^ P in addition to at least one additional step of impacting and at least one additional step of separating by means of eddy current.
18. 18. A system for recovering a product having a significant concentration of a metal from compositions of 20 lumps of various sizes of metal and other matter, the lump compositions of various sizes containing varying amounts of the metal, comprising: means for impacting the lump compositions of various sizes to obtain lumps of reduced size; and means, operatively connected to the means for impacting, to separate by parasitic current the lumps of reduced size into lumps of reduced size of significant concentration and lumps of reduced size of less than significant concentration.
19. 19. The system of claim 18, further comprising: at least additional means for impacting clumps of reduced size of less than significant concentration to obtain lumps plus small pegs, the at least additional means for impact being operatively connected to the means to separate by parasitic current; and at least additional means, operatively connected to the at least additional means for impact, to separate by parasitic current the smaller clumps of smaller size into smaller clumps of reduced size of significant concentration and smaller clumps of reduced size of concentration less than significant.
20. 20. A system for recovering a product having a significant concentration of a metal from clod compositions of various sizes of metal and other matter, the compositions of clods of various sizes containing varying amounts of the metal, comprising: impact device to shred the clod compositions of various sizes to obtain lumps reduced in size; and a parasitic current separator, operatively connected to the means for impacting, to separate the lumps reduced in size into lumps reduced in size of the significant concentration and the lumps reduced in concentration size less than the significant. The system of claim 20, further comprising: at least one additional impact device for shredding the reduced lumps in less than significant concentration size to obtain reduced lumps in smaller size, the at least one additional impact device being connected operatively to the parasitic current separator; and at least one additional parasitic current separator, operatively connected to at least one additional impact device, to separate the smaller lumps reduced in size into smaller lumps in smaller size of significant concentration and smaller lumps in smaller size of less concentration meaningful