WO2023158294A1 - Aluminium recycling process - Google Patents

Abstract

Disclosed is a highly efficient process for recycling aluminium, capable of recovering a high percentage of high-purity aluminium from a variety of waste materials (scrap), which uses minimal energy and has very low carbon emissions, being environmentally friendly (sustainable).

Description

ALUMINUM RECYCLING PROCESS

BACKGROUND OF THE INVENTION

A. FIELD OF THE INVENTION

The present invention is related to processes for recycling aluminum, and more particularly with a highly efficient process for recycling aluminum that has the capacity to recover a high percentage of aluminum present in the raw material that has a great diversity of materials of waste (scrap), with a minimum possible energy consumption and with very low carbon emissions, being friendly to the environment (sustainable).

B, DESCRIPTION OF THE RELATED ART

The aluminum recycling industry is mainly based on two main processes:

1. Melting processes using Rotary Furnaces where the aluminum scrap is not previously treated, in said process a reduction between 5 and 10% greater than the most efficient process possible is generated, generating a greater amount of slag that will have to be confined, which it causes a lot of waste, on the other hand, during the melting process, volatile particles are generated that are mostly organic, which are not stabilized and are only diluted in the best of cases, resulting in unclean processes with high CO2 emissions and others. gases into the atmosphere.

The quality of the finished product that is obtained is not very good since many of the impurities present in the scrap that are not aluminum are incorporated into the aluminum alloy, so these alloys are used to produce products with low quality requirements.

2. Fusion processes using a previous aluminum scrap treatment process that removes a part of impurities, mainly magnetic elements. This allows a slightly higher recovery, but with losses of between 3 to 7% greater than the most efficient process possible. During the melting process, volatile particles are also generated, which are mostly organic, which are not stabilized and are only diluted in the best of cases, resulting in an unclean process with high CO2 emissions into the atmosphere. The quality of the finished product obtained is slightly better than that obtained with the rotary kiln process, without being extraordinary.

Therefore, there is a need for an aluminum recycling process that is highly efficient and environmentally friendly.

In view of the previously described need, the applicant developed a process for aluminum recycling starting from aluminum scrap which is capable of recovering the maximum percentage of aluminum possible (up to 96% aluminum in the raw material), with a minimum possible energy consumption and with very low carbon emissions, being friendly to the environment (sustainable).

The process for recycling aluminum of the present invention comprises the general steps of: submitting said waste material to a grinding and recovery process for aluminum scrap that can separate a high percentage of waste material from aluminum; subjecting the recovered aluminum to a delacquering and/or preheating process, where the generated (pyrolytic) gases are used as fuel; later they are fed to a fusion process with a Vortex system and finally to a continuous casting process.

Some of the benefits of the aluminum recycling process of the present invention include:

• Increases the aluminum recovery percentage by up to 10% by reducing metal losses.

• Minimizes the use of salts and fluxes because clean raw material without organic materials enters the melting process.

• Revalues scrap by increasing the percentage of its use in alloys, reducing the use of primary aluminum as a consequence of removing impurities.

• Reduces energy consumption by using the organic materials present in the scrap as fuel during the stripping stage.

SUMMARY OF THE INVENTION It is therefore a main objective of the present invention to provide a process for recycling aluminum starting from aluminum scrap which is capable of recovering the maximum percentage of aluminum possible, with the minimum possible energy consumption, with low slag generation ( materials to confine) and with very low carbon emissions, being friendly to the environment (sustainable).

It is still another main objective of the present invention, to provide a process for the recovery of aluminum of the nature described above, which comprises the general steps of: submitting said waste material to a process of grinding and valorization of aluminum scrap that can separate a high percentage of impurity material (waste) from the aluminum; subjecting the recovered aluminum to a stripping process, where the gases produced are used as fuel; later to a fusion process with a Vortex system and finally to a continuous casting process.

It is an additional main objective of the present invention, to provide a process for the recovery of aluminum of the nature described above, which has several benefits, some of which are: it increases the percentage of aluminum recovery by reducing metal losses ; it minimizes the use of salts and fluxes because clean raw material without organic materials enters the melting process; revalue scrap by increasing the percentage of its use in alloys, reducing the use of primary aluminum as a consequence of removing impurities; reduces energy consumption by using the organic materials present in the scrap as fuel during the stripping stage.

These and other objects and advantages of the present invention will become apparent to those of ordinary skill in the art from the following detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION.

The process for recycling aluminum of the present invention will now be described with reference to a preferred embodiment thereof, Raw material Before being processed, the raw material is weighed, stored. Some of the types of raw material that are accepted by the process of the present invention are summarized in the following table:

★Description of raw material in accordance with the classification for aluminum materials described in the “Scrap Specifications Circular”; January 21, 2016; Institute of Scrap Recycling Industries, Inc.

Each raw material has different characteristics that are associated with thickness, content of paints, fats or organic materials.

Raw materials are divided into two groups, thick materials with thicknesses greater than 2 mm (numbers 1, 2, 8 and 9 of the table) and thin materials with thicknesses less than 2 mm (numbers 3, 4, 5, 6, and 7 of the table).

However, the process can process feedstock comprising scrap or waste material with any amount of aluminum content.

It should be understood that these types of raw materials are not exclusive or limiting since it is possible to use other types of aluminum scrap or raw materials, since those listed are mentioned for reference only. a) Stage of grinding and removal of impurities

The first stage of the process for recycling aluminum of the present invention comprises the stage of grinding and removal of impurities, which is divided into the following substages:

I. Primary grinding: in the primary grinding substage, the raw material is fragmented into pieces of between 100mm and 300mm in a grinding equipped with cutting blades with scissor effect known in the art adjusted to produce pieces of between 100mm to 300mm, or by any other suitable grinding equipment or method;

II. Secondary grinding: in the secondary grinding substage, the pieces obtained in the primary grinding with sizes between 100mm and 300mm are fragmented into fragments smaller than 100mm in a grinding apparatus equipped with cutting blades with scissor effect known in the art, adjusted to produce fragments smaller than 100mm or by any other suitable grinding equipment or method.

III. Screening: in the screening substage, fines smaller than 10mm are removed from the raw material fragmented in the previous substage using a screen with a 10mm mesh size. Said fines mainly comprise impurities adhered to the different raw materials as well as small fragments of aluminum with a size of less than: 10mm. Thanks to the screening, a uniform fragment size between 10mm and 100mm is guaranteed. In a preferred modality, the grinding apparatus with cutting blades of the secondary grinding has a sieve integrated into the apparatus at each output of the fragments, so that in said modality, the screening stage is carried out in the same grinding apparatus. from secondary grinding;

IV. Remove iron fragments. In this substage, the iron fragments that remained after screening, with sizes between 10mm and 100mm, are removed from the fragmented raw material by means of a magnetic drum (known in the art) that attracts said iron fragments or any other method or device. adequate iron separator;

V. Remove fragments of inert material. In this stage, the fragments of inert material (everything that is not metallic) with sizes between 10mm to 10Omm, are removed from the aluminum fragments of the raw material by using a known “Eddy current” inert material separator equipment. in art, or by any other suitable equipment or method; SAW. Remove heavy metals. In this stage, heavy metal fragments with sizes between 10mm and 100mm are removed from the aluminum fragments of the raw material by means of a table equipment for densimetric separation in which the air flow is adjusted for aluminum, so that other elements with higher densities (heavy metals) they are separated and removed as impurities, or by other heavy metal separation equipment or method known in the art;

In an embodiment of the present invention, the thick materials and the thin materials are processed in the present stage a) separately or in different processing lines, in such a way that they enter stage b) to be processed separately or in different processing lines.

The product of the grinding and removal of impurities stage comprises fragmented aluminum scrap in a uniform size in a range between 10mm to 100mm, up to 99% free of impurities such as iron, lead, copper, zinc, wood, plastic, paper etc

The shredded aluminum scrap is transferred to the next stage of the process by any known means, such as conveyor belts, ideally continuously or until the next stage can process it.

The size of raw material that enters substage I depends on the capacity of the grinding apparatus used (that is, it can have any size), as long as said grinding apparatus used in substage I can produce pieces between 100mm at 300mm. b) Deslacquering stage

Much of the aluminum scrap contains 3% to 4% organic waste (paint, lacquer, etc.) such as beverage containers, construction profiles or sheets used for transport, so the aluminum scrap obtained in The stage of grinding and removal of impurities is subjected to a removal process called stripping, which consists of heating the fragmented aluminum scrap (subjecting it to a thermal process) in an oven until these materials are detached. organics in the form of gases, typically at a temperature between 400 ^s C to 550 ^s C.

In a preferred modality, the delacquering process is carried out using a system called IDEX® which is designed to subject aluminum scrap to a thermal process to eliminate volatile organic (paint, lacquer, oils) and inorganic (water) contaminants from a wide range of aluminum scrap through a continuous thermal process.

According to what is described in step a), the thick materials and the thin materials that come out separately from step a) are also processed separately in the present step b) and can be processed in two separate processing lines.

In accordance with the above, using the IDEX® stripping system, the temperature is adjusted between 500°C and 550°C at 30 rpm in the rotating kiln for the group of thick raw materials and for the group of thin raw materials the temperature it is set between 400°C and 500°C at 20 rpm on the rotating kiln. The material leaves the thermal process at a temperature between 400 ^s C to 550 ^s C. The reason for this is that the thickness of the raw material does not change after the primary and secondary grinding sub-stages.

However, stripping can be carried out in any other oven or suitable stripping equipment that has a heating zone where the thermal process can be carried out at temperatures suitable for any type of raw material.

Because the next stage involves melting, there is no longer a need to separate the thick and thin materials, although in other embodiments of the invention they may still be processed separately on different processing lines.

The product of the stripping stage comprises aluminum scrap without any organic residue content (0%) which is transferred to the next stage of the process by any known means such as conveyor belts, ideally continuously or until the next stage stage is ready to process the aluminum scrap. c) Fusion stage The aluminum scrap obtained in the stripping stage is subjected to a continuous melting process in the absence of air. The melting process is carried out in a melting furnace that has a Vortex-type system that forms a whirlpool of molten aluminum (vortex well) at a temperature between 700°C and 750°C, where the aluminum scrap is immersed in the aluminum bath so that it melts, avoiding contact with the air, minimizing the oxidation of the metal. In a preferred embodiment, the Vortex-type melting furnace has a capacity of 125 tons and is maintained at a temperature between 720 ^s C and 750 ^s C. During the smelting process, aluminum by-products are generated, which are mostly oxides in the surface of the liquid aluminum, said by-product is removed from the furnace for surface cleaning. The molten material in a liquid state is transferred by means of a graphite pump to the next stage of the process of the present invention by any known means, for example, by means of channels with flow control, maintaining a continuous flow of material, until the tank is filled. next stage holding furnace; d) Stage of adjustment of composition and refining.

The molten aluminum produced in the melting stage is transferred, for example, by means of channels with flow control, maintaining a continuous flow of material to one or more aluminum holding furnaces where the aluminum is maintained at a temperature between 700 ^s C to ^760s C.

In these maintainer furnaces, the process of adjusting the chemical composition (alloy) is carried out according to any specification required by an end customer, which is achieved by adding addition elements to the molten aluminum. Additionally, aluminum refining is carried out.

Composition and refinement adjustment is done as follows:

I. transfer the molten aluminum to one or more holding furnaces; and for each holding furnace:

II. One or more samples of aluminum are taken from the one or more holding furnaces using any suitable means, such as by means of a spoon;

III. Said one or more samples are analyzed for metal content using any known method to specifically determine which are the metals present in the one or more samples and the amount of addition elements to be added, which are selected from the group that includes, but is not limited to: silicon, copper, magnesium, manganese, zinc, titanium. Obviously during an initial taking of one or more samples, the aluminum content will be predominant:

IV. The addition elements that are required according to the results of the analysis are added to the molten aluminum to comply with the product specification requested by the client.

V. Carry out the refining and cleaning of metal by any known method, which generally includes removing any by-product present on the surface of the liquid aluminum (which includes undesirable material) and removing it from the holding furnace using any suitable instrument for that purpose, such as a spoon.

SAW. Repeat substages II to VI until obtaining the requested specification. Vile. Release the molten material to the next stage of the method.

VIII. Repeat steps i to VIII

In these holding furnaces, metal refining and cleaning processes are also carried out, removing any by-product present on the surface of the liquid aluminum and removing it from the furnace through the door.

The product of the composition adjustment step comprises refined liquid molten aluminum with its chemical composition adjusted according to specifications predefined by a customer.

In a preferred embodiment of the process of the present invention, there are four holding furnaces with a capacity of 25 tons each.

Likewise, in said preferred modality, there are at least two holding furnaces to optimize the emptying of the furnaces for the following stages of the process, which includes filtering and continuous casting, since while one holding furnace is emptying, another is in the process of refining and alloy setting. Therefore, in other modalities preferably, there must be a number of holding furnaces such that it allows in all time to have a holding furnace ready to be emptied to the next stage of the process in such a way that it has the capacity to continuously provide refined molten aluminum with its adjusted chemical composition.

Molten aluminum in a liquid state is transferred to the next filtering stage by tilting the furnace (tilting it) or by any known means, such as flow-controlled channels. e) Filter stage

The molten aluminum that comes out of the composition adjustment and refining stage is led to a filter box where filtering is carried out by means of a ceramic filter with between 20 to 50 PPI (pores per square inch), where said filtering retains either inclusion, intermetallic particles, or any additional material that was present in the molten aluminum.

The filtered aluminum exiting the lauter box is led to the next stage of continuous casting by any known means, such as flow-controlled channels, ideally continuously or until the next stage is ready to process the molten aluminum. . f) Continuous casting stage

The filtered aluminum that leaves the previous stage is led and deposited continuously by any known method or means (for example, through channels with flow control), in a continuous ingot casting machine, which forms aluminum ingots of regular shape, preferably with a flat upper and lower surface, and cools them by means of pressurized water jets. Any known or available casting method or machine can be used.

In a preferred embodiment, the liquid metal is solidified using pressurized water. Once the aluminum has solidified, a bar is formed, which passes to a section where it is identified and cut with a guillotine-type system to obtain an ingot of approximately 10 kg each, once the ingots are cut at a temperature between 350°C and 450°C is transported to a cooling tunnel where the ingots are cooled to 60°C The product of the continuous casting stage comprises refined aluminum ingots, with tight composition, free of oxides, of a regular size and shape that makes them easy to stow, ready for shipment.

During the substages of I. primary grinding and II. Secondary grinding of the stage of a) grinding and removal of impurities, a series of by-products are generated that are removed in substages II and III and which are described below:

In the preferred embodiment, the apparatus used in the substages of I. primary grinding and II. Secondary milling have dust collection systems with thirteen commercially available collection points to avoid dust emissions into the atmosphere.

In said preferred embodiment, said dust collection equipment comprises: a Pule Jef Type filter bag collector. ; the collector will have a configuration of 3 to 4 hoppers, with an air lock rotary valve for the discharge of material in each hopper; there are 2 cyclones for the separation of garbage and larger materials (that are not powders), this system has a nominal capacity of 870 bags, it has a direct coupling extractor, arrangement 8 with type C anti-spark construction, which is installed on the clean side of a manifold with BAU discharge, to connect a self-supported chimney on the floor.

In other embodiments, any other commercially available dust collection method or system may be used.

Thanks to the use of grinding devices equipped with cutting blades in substages I and II, the generation of dust and therefore the loss of material is reduced, compared to other grinding systems, such as hammer mills. In stage b) delacquering, it is very important that the process used (IDEX®) does not enter oxygen to avoid combustion inside the equipment where the process is carried out.

During the delacquering process, gases are obtained that are released from the organics present in the raw material which, in a preferred modality of the process of the present invention, are conducted to equipment called "after burner" where these gases are used as fuel to heat the gases necessary for the heating system of the equipment where the stripping is carried out. It should be noted that the gas recovery system includes commercially available equipment.

In this way, the gases produced in the stripping stage are used as fuel in the stripping equipment itself, which helps to have a self-sufficient process where natural gas consumption is reduced. Ideally, the stripping equipment used in stage b) should have a high-temperature incinerator to ensure that no polluting or harmful elements will be emitted to the environment.

During stage b) lacquering, the following by-products are generated:

Since the scrap that comes out of stage b) of stripping is at a temperature between 350 ^s C to 500 ^s C, less energy is consumed in stage c) of melting by feeding preheated material to the melting furnace. For this reason, it is important that the stripping equipment and the melting furnace are close to each other, so that the preheated scrap can be cooled considerably (for example, to less than 300 ^s C).

During stage c) of melting, aluminum by-products are generated in the melting furnace, which are mostly oxides on the surface of the liquid aluminum. Said by-product is removed from the furnace for surface cleaning using known techniques and means. This practice is done to ensure the quality of the finished product. During the c) fusion process, the following by-products are specifically generated:

In stage d) composition and refining, the following by-products are generated:

In the preferred embodiment of the invention, stages b), c) and d) additionally comprise sub-stages for collecting and filtering fumes and dust using known or commercially available methods and systems, since the stripping equipment, melting furnace and holding furnaces each one has anti-pollution systems for the collection and filtering of smoke. Additionally, the anti-pollution systems have filters that have additives (lime and activated carbon) to avoid any type of emission into the atmosphere.

In said preferred modality, the melting furnace has an equipment for controlling emissions into the atmosphere that includes: a heat-insulated sleeve filter box with a cassette-type filter with flat bags and a low-pressure reverse flow cleaning system for suction and treatment of 100% of the gases generated, having 6 suction points during the fusion process. The filtering surface is 3,360/3,172 m ² , with 2,240 filter bags, with an extraction fan that has a total flow of 165,000 Am3/hr and a 2 x 132 kW motor at 1,800 rpm and 440 V. It has a dosing system with storage silo, dosing and pneumatic transport of t mix additives of Ca (OH)2 and Activated Carbon from 7 to 14 l/h.

All the by-products (1 to 10) that are generated by the process of the present invention can be subjected to a recovery stage in a recovery line using rotary kilns, by means of already known processes. Through these processes, between 30% and 40% of aluminum will be recovered from all by-products. Ideally, the flow of material between one stage to another of the process for the recovery of aluminum of the present invention occurs continuously, however, the flow of material can be interrupted from one stage to another depending on the amount of material and the processing capacity of the equipment used in each stage, as long as the last stage f) of casting is carried out continuously. Experts in the field can suggest adjustments in each stage of the process of the present invention so that the last stage f) of casting is carried out continuously.

In the smelting stage, another smelting method could be used, however, said smelting method must be prepared to melt and provide molten aluminum continuously, have anti-pollution equipment and guarantee maximum use of aluminum: less waste of 5%, that is, obtain 95% aluminum.

Finally, the entire method can be performed simultaneously on two or more parallel processing lines.

Specific advantages of the method of the present invention over known aluminum recycling methods.

• The use of aluminum is increased by up to 10%.

• The consumption of natural gas is reduced.

• The overall carbon footprint is reduced.

• Lower emission and pollutant control standards are maintained.

• The emission of dioxins and furans is avoided thanks to the systems and equipment that are incorporated during the process.

• The consumption of salts and fluxes that later become waste is reduced.

• The generation of waste that is sent to confinement centers is reduced.

Finally, it should be understood that the aluminum recycling process of the present invention is not limited to the modality described above and that experts in the field will be enabled, by the teachings established herein, to make changes in the recycling process. aluminum stock the present invention, the scope of which will be established exclusively by the following claims.

Claims

CLAIMS A process for recycling aluminum from waste raw material with aluminum content, characterized by comprising the following stages: a) Stage of grinding and removal of impurities to obtain aluminum fragments in a uniform size in a range between 10mm to 100mm, up to 99% free of impurities, where said stage of grinding and removal of impurities comprises the following sub-stages: I. primary grinding, which comprises fragmenting the raw material into pieces of between 100mm to 300mm by means of a grinding apparatus; II. secondary grinding, which comprises fragmenting the pieces obtained in the primary grinding into fragments smaller than 100mm by means of a grinding apparatus; III. screening, which comprises removing fines smaller than 10mm from the raw material fragmented in the previous substage by means of a sieve with a 10mm mesh size, thus obtaining a raw material with fragments of a size between 10mm and 100mm; IV. remove iron fragments that remained after screening the raw material, with sizes between 10mm and 100mm, by means of an iron separator device; V. Remove fragments of inert material with sizes between 10mm to 100mm, from the aluminum fragments of the raw material by using an inert material separator equipment; b) delacquering stage, which comprises subjecting the aluminum fragments obtained in the previous stage to a thermal process in the absence of oxygen to eliminate volatile organic contaminants in the form of gases using equipment that has a heating zone to carry out said thermal process In absence of oxygen in order to obtain aluminum fragments without any content of organic residues (0%); c) melting stage, which comprises subjecting the aluminum fragments obtained in the previous stage to a melting process in the absence of air in a melting furnace with a Vortex-type system to obtain fluid molten aluminum; d) composition and refining adjustment stage, the purpose of which is to obtain refined liquid cast aluminum with its chemical composition adjusted in accordance with predefined specifications, wherein the composition and refining adjustment stage comprises the following sub-stages: I. transfer the molten aluminum to one or more holding furnaces; for each holding furnace: II. take one or more samples of aluminum from the one or more holding furnaces using any suitable means; III. analyze the metal content of the one or more samples using any known method to specifically determine which are the metals present in the one or more samples and the amount of addition elements to add, which are selected from the group that includes but is not limited to a: silicon, copper, magnesium, manganese, zinc, titanium; IV. add to the molten aluminum the addition elements that are required according to the results of the analysis for compliance with the predefined specification; V. carry out the refining and cleaning of the metal, which includes removing any undesirable by-product present on the surface of the liquid aluminum and removing it from the holding furnace using any suitable instrument for this purpose, such as a spoon; SAW. repeating sub-steps II to VI until the predefined chemical composition specification is obtained; Vile. Release the molten material to the next stage; VIII. Repeat substeps I to VI; e) filtering stage, which comprises conducting the molten aluminum obtained in stage d) to a filter with between 20 to 50 PPI (pores per square inch), where a filtering is carried out to retain either inclusion, inter-metallic particles or any additional material that was present in the cast aluminum; f) casting stage, in this stage the filtered aluminum that comes out of the previous stage is conducted and deposited continuously in a continuous ingot casting machine, which forms aluminum ingots, in such a way that the casting stage produces Refined aluminum ingots, with adjusted chemical composition, free of rust. 2. A process for recycling aluminum in accordance with claim 1, wherein in substage I of stage a) the primary grinding is carried out in a grinding apparatus equipped with cutting blades with a scissor effect. 3. A process for recycling aluminum in accordance with claim 1, wherein in substage II of stage a) the secondary grinding is carried out in a grinding apparatus equipped with cutting blades with a scissor effect. 4. A process for recycling aluminum in accordance with claim 1, wherein the secondary grinding of substage II of stage a) and the screening of substage III of stage a) are carried out in a single stage, using a grinding apparatus that has an integrated screen with a mesh size of 10mm in each output of fragmented material. 5. A process for recycling aluminum according to claim 1, wherein in substage IV of stage a) the iron fragments are removed by means of a magnetic drum that attracts said iron fragments. 6. A process for recycling aluminum in accordance with claim 1, wherein substage V of stage a) is carried out using an "Eddy current" equipment. 7. A process for recycling aluminum in accordance with claim 1, wherein stage b), the thermal process is carried out in an oven at a temperature between 400 ^s C to 550 ^s C. 8. A process for recycling aluminum in accordance with claim 1, wherein stage b) of delacquering is carried out in a system called IDEX®. 9. A process for recycling aluminum in accordance with claim 1, wherein: an initial stage is included that comprises dividing the raw material into the following groups: thick materials with thicknesses greater than 2 mm and thin materials with thicknesses less than 2mm, in step a) thick materials and thin materials are processed separately and come out separately; in stage b) the thick materials and the thin materials that come out separately from stage a) are processed separately using a system called IDEX®, where the temperature is adjusted between 500°C and 550°C at 30 rpm in the rotating kiln for thick materials and for the group of thin materials the temperature is adjusted between 400°C and 500°C at 20 rpm in the rotating kiln. 10. A process for recycling aluminum in accordance with claim 1, wherein in step c) the melting process is carried out at a temperature between 700°C and 750°C. 1 1. A process for recycling aluminum in accordance with claim 1, wherein in step d) the aluminum is maintained at a temperature between 700 ^s C to 760 ^s C in the maintainer furnaces. 12. A process for recycling aluminum in accordance with claim 1, wherein stage d) is carried out in a number of holding furnaces such that it allows at all times to have a holding furnace ready to be emptied to the next stage of the process. in such a way that it has the ability to continuously provide refined molten aluminum with its adjusted chemical composition. 13. A process for recycling aluminum in accordance with claim 1, wherein step f) produces aluminum ingots of regular shape, preferably with a flat upper and lower surface. 14. A process for recycling aluminum in accordance with claim 1, wherein substages I and II of stage a) additionally comprise dust collection using commercially available dust collection equipment, preferably dust collection equipment that They comprise: a Pule Jef Type filter bag collector. with a configuration of 3 to 4 hoppers, with an air lock type rotary valve for the discharge of material in each hopper; two cyclones for the separation of materials that are not powders; a direct coupled exhaust fan, arrangement 8 with non-spark type C construction, installed on the clean side of a manifold with BAU discharge, to connect a self-supported floor chimney. 15. A process for the recycling of aluminum in accordance with claim 1, wherein in stage b) the stripping equipment has a gas recovery system, preferably an equipment called "after burner" where the gases are used. that are released from organic compounds during stripping, as fuel for the heating system of the equipment where stripping is carried out. A process for recycling aluminum in accordance with claim 1, wherein steps b), c) and d) further comprise the collection and filtering of fumes and dust using known anti-pollution systems. A process for recycling aluminum in accordance with claim 1, wherein in stage c) the melting furnace has equipment to control emissions into the atmosphere that comprises: a heat-insulated sleeve filter box with a cassette-type filter with flat bags and low pressure reverse flow cleaning system for aspiration and treatment of 100% of the gases generated, having 6 suction points during the melting process; where the filtering surface is 3360/3172 m ² ; 2,240 filter bags, with an extraction fan that has a total flow of 165,000 Am3/hr and a 2 x 132 kW motor at 1,800 rpm and 440 V; and a dosing system with storage silo, dosing and pneumatic transport of mix additives of Ca (OH)2 and activated carbon from 7 to 14 l/h. A process for recycling aluminum in accordance with claim 1, further comprising subjecting the by-products of: substages I and II of stage a); of stage b); from stage c) and stage d) to a recovery stage in a recovery line using rotary kilns, by known processes in order to recover between 30% to 40% of the aluminum present in the by-products.