WO2025228796A1

WO2025228796A1 - Apparatus and method for treating and recovering ash from an incinerator or waste-to-energy plant

Info

Publication number: WO2025228796A1
Application number: PCT/EP2025/061270
Authority: WO
Inventors: Antonio GOFFI
Original assignee: RMB SpA
Current assignee: RMB SpA
Priority date: 2024-04-30
Filing date: 2025-04-24
Publication date: 2025-11-06
Anticipated expiration: 2026-10-30

Abstract

An apparatus (1) for treating and recovering ash which comprises a loading hopper (2) adapted to receive wet ash to be treated in order to feed it into a first screening device (3) configured to dimensionally separate the ash to send it to respective magnetic separation devices (4a, 4b, 4c, etc.) that are adapted to separate the ferrous fraction to send it to a ferrous residue containment vessel (11), at least one of the magnetic separation devices (4a, 4b) which act on smaller size ranges comprising, respectively, a first magnetic separation element (4a', 4b') and a second magnetic separation element (4a'', 4b'') between which a second screening device (5) is interposed; the magnetic separation elements (4a', 4b', etc.) being configured to send the nonmagnetic material to a second nonferrous metal separator (8) and the nonmetallic fraction, depending on the size range, to a first aeraulic device (21) or to a crusher/mill (22a).

Description

APPARATUS AND METHOD FOR TREATING AND RECOVERING ASH FROM AN INCINERATOR OR WASTE-TO-ENERGY PLANT

The present invention relates to an apparatus and a method for treating and recovering ash from an incinerator or waste-to-energy plant.

Ash, and in particular heavy ash, constitutes a heavy unburned residue of incineration of solid waste, and represents approximately a percentage of 15% - 25% by weight of waste converted to energy.

It is substantially a granular material, constituted mainly by a mineral fraction (85-90%), as well as by ferrous metals (7-15%) and nonferrous metals (1-2%).

Three types of methods are normally used.

Wet extraction and dry treatment: this is the most established method; it requires a maturation time for subsequent use in the construction sector. It is characterized by a poor efficiency in the recovery of metals with dimensions smaller than 2 mm.

Wet extraction and wet treatment : this method offers an improvement in the quality of the materials for use in the construction sector, as well as good efficiency in the recovery of metals, including of dimensions smaller than 2 mm. By contrast, this method entails a considerable consumption of water, high production costs, and the production of sludge which then needs to be disposed of.

Dry extraction and dry treatment: this method is characterized by a high efficiency in the recovery of metals, even of the smallest fractions. However, its principal drawback is a high generation of dust.

The aim of the present invention is to provide an apparatus and a method for treating and recovering ash from an incinerator or waste-to- energy plant that is capable of improving the known art in one or more of the abovementioned aspects.

Within this aim, an object of the invention is to make available an apparatus and a method for treating and recovering ash from an incinerator or waste-to-energy plant that can appreciably reduce the costs of disposal while ensuring, at the same time, that the separated material is of extremely high quality.

Another object of the invention is to provide an apparatus and a method for treating and recovering ash from an incinerator or waste-to- energy plant that is highly reliable, easy to implement and has low cost.

This aim and these and other objects which will become more apparent hereinafter are achieved by an apparatus and by a method for treating and recovering ash from an incinerator or waste-to-energy plant according to the independent claims, optionally provided with one or more of the characteristics of the dependent claims.

Further characteristics and advantages of the invention will become more apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the apparatus and of the method for treating and recovering ash from an incinerator or waste-to-energy plant according to the invention, which are illustrated, by way of non-limiting example, in the accompanying drawings wherein:

- Figure 1 is a diagram of the apparatus according to the invention.

With reference to the figure, the apparatus according to the invention, generally designated by the reference numeral 1 , comprises an apparatus for treating and recovering ash from an incinerator or waste-to-energy plant.

The apparatus 1 comprises at least one loading hopper 2, which is adapted to receive wet ash to be treated in order to feed it to a screening device 3 which is configured to dimensionally separate the ash arriving from the loading hopper 2 in order to send it, depending on its size range, to respective magnetic separation devices (4a, 4b, 4c, etc.).

Preferably, the loading hopper 2 is made of steel and is composed of a tub for containing the material, which is dropped and dosed by means of a metal catenary fitted with a motor and gear reducers.

Conveniently, the loading hopper 2 is operationally associated with a weighing device, which comprises for example load cells (extraction weight station) and is configured to weigh the incoming material and the outgoing material to/from the loading hopper 2.

The flow of ash output by the loading hopper 2 is regulated, advantageously, by way of the use of an oscillating partition that optimizes the flow output onto a belt arranged downstream of the loading hopper 2 and adapted to send the ash to be treated to the respective magnetic separation devices (4a, 4b, etc.).

A cover is fixed to the upper part of the loading hopper 2 and serves to capture any dust during loading; this cover is connected to an aspiration duct.

The magnetic separation devices (4a, 4b, 4c, etc.) are adapted to separate the magnetic fraction (ferrous and nonferrous) in order to send it to at least one ferrous residue containment vessel 11.

At least one of the magnetic separation devices (4a, 4b) acting on size ranges smaller than the size ranges treated by the remaining magnetic separation devices (4d, 4e) comprises, respectively, a first magnetic separation element (4a', 4b') and a second magnetic separation element (4a", 4b"), between which a second screening device 5 or vibrating screen is interposed.

In particular, the material of smaller size range is treated by the respective first magnetic separation element (4a', 4b', etc.) and therefore the material not intercepted as magnetic by the first magnetic separation elements (4a', 4b', etc.) is sent to the second screening device 5.

The second screening device 5 is configured to send the larger size ranges to the respective second magnetic separation elements (4a", 4b"), and the smaller size ranges to a ballistic separator 6.

The ballistic separator 6 is configured to send the light fraction to a fine fraction containment vessel 12, and the heavy fraction to a first nonferrous metal separator assembly 7. Preferably, arranged between the ballistic separator 6 and the first nonferrous metal separator assembly 7 are, in sequence, a magnetic separator 51a, which is configured to send the ferrous fraction arriving from the ballistic separator 6 to at least one ferrous residue containment vessel 11, and the nonferrous fraction to the first nonferrous metal separator assembly 7.

The first nonferrous metal separator assembly 7 comprises, in a cascade arrangement, a first upstream induction separator 7a and a first downstream induction separator 7b.

Conveniently, a screen 51b, and in particular a vibrating screen, is arranged between the first magnetic separator 51a and the first nonferrous metal separator assembly 7.

In this case, the screen 51b separates the accepted screened fraction, which is sent to the first upstream induction separator 7a, while the rejected oversize fraction is sent to a second upstream induction separator 7a’, followed by a second downstream induction separator 7b’.

There is no reason why the screen 51b cannot be arranged upstream of the first magnetic separator 51a.

The first nonferrous metal separator assembly 7 is configured to separate the (nonferrous) metals from the (mineral) nonmetallic residues.

The nonmetallic residues, containing a light fraction (for example volatile paper fragments, are in turn conveyed to a nonmetallic residue containment vessel 13, while the nonferrous metal residues are sent to a nonferrous metal residue containment vessel 14.

Furthermore, upstream of the separator assembly 7 an aeraulic separation is performed of the volatile light fraction, which is also sent to the nonmetallic residue containment vessel 13.

The magnetic separation devices (4a, 4b, etc.) can comprise conveyor belts with a magnetic head pulleys, which are used to separate iron from the material before it reaches the nonferrous metal separators: such conveyor belts have substantially the same characteristics as traditional conveyor belts, except for the traction roller which contains a ferrite and/or neodymium magnet.

With reference to the first nonferrous fraction separator 51a, it is also possible to use magnetic separator belts, commonly called overbelts, which perform the same function but are arranged transversely or longitudinally above the conveyor belts. The iron that is attracted upward, i.e. toward the magnetic plate placed inside the magnetic separator, remains stuck to the rubber belt of the separator, which, circulating continuously, unloads the separated material into special collection channels or containers.

The magnetic separation devices (4a, 4b), and in particular the second magnetic separation elements (4a”, 4b”, etc.), are configured to send the nonmagnetic material to a second nonferrous metal separator 8, typically an induction separator, which is configured to send the nonferrous metallic materials to a nonferrous metal containment vessel 14 and the nonmetallic fraction, depending on the size range, to:

- a first aeraulic device 21 configured to treat the incoming nonmetallic fraction of smaller size range, to separate the heavy fraction to be sent to a nonmetallic residue containment vessel 13 from the light fraction to be sent to a light fraction containment vessel 15;

- a crusher/mill 22a configured to treat the incoming nonmetallic fraction of intermediate and larger size range, said crusher/mill 22a having, downstream, a third screening device 22b designed to send the rejected oversize fraction to a second aeraulic device 22 and the accepted screened fraction to an induction separator 23.

The second aeraulic device 22 is configured to send the light fraction to a light fraction containment vessel 15 and the heavy fraction to an induction separator 24 in turn configured to send the metal fraction to a nonferrous metal residue containment vessel 14 and the nonmetallic fraction to an optical selector 25; the optical selector 25 is configured to convey the nonmetallic residues to a mineral residue containment vessel 16 and the nonferrous metal residues, for example steel or other metals, to a nonferrous metal residue containment vessel 15.

The induction separator 23 is by contrast configured to convey the metallic fraction to a nonferrous metal containment vessel 14 and the nonmetallic fraction to a mineral residue containment vessel 16.

A third aeraulic device 26 is configured to treat the incoming nonmetallic fraction of larger size range and is provided, upstream, with a manual separation station 26a, the third aeraulic device 26 being configured to separate the light fraction, to be sent to a light fraction containment vessel 15, from the heavy fraction, to be sent to a nonmetallic residue containment vessel 13.

According to a particularly important aspect of the present invention, between the first magnetic separation elements (4a’, 4b’, etc.) and the second magnetic separation elements (4a", 4b", etc.) and the ferrous residue containment vessel 11, there is an additional extraction-type magnetic separator 41 to which the magnetic fractions separated at the first magnetic separation elements (4a’, 4b’, etc.) and at the second magnetic separation elements (4a”, 4b”, etc.) are conveyed.

In particular, the additional magnetic separator 41 is configured to send any ferrous material refined by the magnetic separation devices (4a, 4b, 4c, etc.) deployed upstream to a ferrous residue containment vessel 11 and the nonferrous material to a third screening device 41a.

The third screening device 41a is configured to send the accepted screened fraction to a leachate containment vessel 17 and the rejected oversize fraction to a second crusher/mill 41b, which is adapted to crush/shred the larger partially magnetic material to send the shredded material back to the ribbon for loading the hopper.

Conveniently, the ballistic separator 6 comprises at least two rotating drums, each one provided with a plurality of beating vanes arranged around the respective lateral surface to intercept the particles fed to the ballistic separator 6 during their free fall toward the respective rotating drum.

Advantageously, the shredders comprise respective hammer mills which have a base body made of metal covered with wear-protection plates, a rotor comprising a central shaft made of tempered steel, and steel wearprotection discs housing hammer supporting shafts.

The rotor rotates on command on a horizontal axis, and the hammers, being coupled by means of the shafts, exit by centrifugal force from their respective seats to determine the crushing of the material passing between an anvil and grates below.

Advantageously, the non-ferrous material separating devices comprise respective eddy current separators ECS comprising a conveyor belt associated, at one end thereof, with a magnetic rotor induction roller configured to generate a magnetic field so that the nonferrous material arriving proximate to the magnetic field is lifted from the conveyor belt and removed, while the inert materials are conveyed separately to a mineral residue containment vessel 16.

Preferably, the aeraulic devices comprise a zigzag aeraulic separator configured to remove the light fraction of heterogeneous materials by means of a countercurrent air flow inside a zigzag duct: the heavy fraction, in bouncing off the "steps" of the duct, separates from the light fraction, which is aspirated, while the heavy fraction falls directly into the lower part of the duct.

With regard to the ferrous residue containment vessel 11 , there can be different vessels Ila, 11b, etc. which are designed to receive, for example, ferrous residues of different size ranges. For example, there can be a first ferrous residue containment vessel Ila to which the ferrous residues arriving from the magnetic separation devices (4d, 4e, etc.) which operate on material in larger size ranges are conveyed, and a second ferrous residue containment vessel 11b to which the ferrous residues arriving from the additional extraction-type magnetic separator 41 are conveyed.

With regard to the nonmetallic residue containment vessels 13, there can be a first nonmetallic residue containment vessel 13a, for receiving the material arriving from the ballistic separator 6, a second nonmetallic residue containment vessel 13b, for receiving the material arriving from the first aeraulic device 21, and a third nonmetallic residue containment vessel 13 c, for receiving the material arriving from the third aeraulic device 26.

With regard to the nonferrous metal residue containment vessels 14, the apparatus can have a first nonferrous metal residue containment vessel 14a for receiving the material arriving from the second nonferrous metal separator 8, and a second nonferrous metal residue containment vessel 14b for receiving the material arriving from the third nonferrous metal separator device 24.

With regard to the light fraction containment vessels 15, the apparatus 1 can have a first light fraction containment vessel 15a for receiving the material arriving from the first aeraulic device 21, and a second light fraction containment vessel 15b for receiving the material arriving from the third aeraulic device 26.

According to a further aspect, the present invention relates to a method for treating and recovering ash from an incinerator or waste-to- energy plant.

The method comprises:

- a step of loading the ash into at least one loading hopper 2 adapted to receive wet ash to be treated;

- a step of feeding the ash contained in the loading hopper 2 into a first screening device 3 configured to dimensionally separate the ash;

- a step of sending the ash arriving from the loading hopper 2, depending on its size range, to respective magnetic separation devices (4a, 4b, 4c, etc.).

The sending step comprises sending the smaller size ranges to at least one first magnetic separation element (4a', 4b') downstream of which there are, in sequence, a respective second screening device 5 for the material not intercepted as magnetic by the first magnetic separation element (4a', 4b').

The second screening device 5 is configured to send the larger (i.e. rejected) size ranges to the respective second magnetic separation elements (4a", 4b"), and the smaller (i.e. accepted) size ranges to a ballistic separator 6.

Subsequently, there is a step of ballistic separation of the smaller size ranges sent to the ballistic separator 6, which comprises a step of sending the light fraction to a fine fraction containment vessel 12 and a step of sending the heavy fraction to a magnetic separation device 51a, and then to the first nonferrous metal separator 7 configured to separate nonferrous metals from nonmetallic residues.

Then comes a step of conveying the nonmetallic residues arriving from the first nonferrous metal separator 7 to a nonmetallic residue containment vessel 13, and a step of conveying the nonferrous metal residues arriving from the first nonferrous metal separator 7 to a nonferrous metal residue containment vessel 14.

Subsequently, there is a step of sending the nonmagnetic material arriving from the magnetic separation devices (4a, 4b, etc.) to a second nonferrous metal separator 8, and a step of sending the nonferrous metals arriving from the second nonferrous materials separator 8 to a nonferrous metal containment vessel 14.

Finally, there is a step of sending the nonmetallic fraction arriving from the second nonferrous materials separator 8, depending on the size range, to:

- a first aeraulic device 21 configured to treat the incoming nonmetallic fraction of smaller size range, to separate the heavy fraction to be sent to a nonmetallic residue containment vessel 13 from the light fraction to be sent to a light fraction containment vessel 15; - a crusher/mill 22a configured to treat the incoming nonmetallic fraction of intermediate and larger size range, said crusher/mill 22a having, downstream, a third screening device 22b designed to send the rejected oversize fraction to a second aeraulic device 22 and the accepted screened fraction to an induction separator 23.

The second aeraulic device 22 is configured to send the light fraction to a light fraction containment vessel 15 and the heavy fraction to an induction separator 24 in turn configured to send the metal fraction to a nonferrous metal residue containment vessel 14 and the nonmetallic fraction to an optical selector 25; the optical selector 25 is configured to convey the nonmetallic residues to a mineral residue containment vessel 16 and the nonferrous metal residues, for example steel, to a nonferrous metal residue containment vessel 15.

Preferably, the method comprises a step of sending the material not intercepted by the second magnetic separation elements (4a", 4b", etc.) to an additional extraction-type magnetic separator 41 configured to send the ferrous material not intercepted by the magnetic separation devices (4a, 4b, 4c, etc.) to a ferrous residue containment vessel 11 and the nonferrous material to a third screening device 41a.

Then comes a step of sending the smaller fraction of the material arriving from the third screening device 41a to a leachate or sludge containment vessel 17, and a step of sending the larger fraction of the material arriving from the third screening device 41a to a second crusher/mill 41b adapted to shred the larger nonferrous material in order to send the shredded material back to the first screening device 2.

In practice it has been found that the invention fully achieves the intended aim and objects by providing an apparatus and a method that are extremely efficient from the point of view of the end result, in terms both of the recovery percentages obtained, and of quality of the separation of the various materials.

The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. 102024000009700 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, such reference signs have been inserted for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. An apparatus (1) for treating and recovering ash from an incinerator or waste-to-energy plant, characterized in that it comprises at least one loading hopper (2) adapted to receive wet ash to be treated in order to feed it to a first screening device (3) configured to dimensionally separate the ash arriving from said loading hopper (2) to send it, depending on its size range, to respective magnetic separation devices (4a, 4b, 4c, etc.) that are adapted to separate the ferrous fraction to send it to a ferrous residue containment vessel (11), at least one of said magnetic separation devices (4a, 4b) acting on size ranges smaller than the size ranges treated by the remaining magnetic separation devices (4d, 4e), and which comprise, respectively, a first magnetic separation element (4a', 4b') and a second magnetic separation element (4a", 4b") between which a second screening device (5) is interposed which is configured to screen the material not intercepted as magnetic by said first magnetic separation elements (4a', 4b', etc.), said second screening device (5) being configured to send the larger size ranges to the respective second magnetic separation elements (4a", 4b") and the smaller size ranges to a ballistic separator (6) configured to send the light fraction to a fine fraction containment vessel (12) and the heavy fraction to a first nonferrous metal separator (7) configured to separate the nonferrous metals from the nonmetallic residues, said nonmetallic residues being conveyed to a nonmetallic residue containment vessel (13) and the nonferrous metal residues being conveyed to a nonferrous metal residue containment vessel (14), said magnetic separation devices (4a, 4b, etc.) being configured to send the nonmagnetic material to a second nonferrous metal separator (8) configured to send the nonferrous metals to a nonferrous metal containment vessel (14) and the nonmetallic fraction, depending on the size range, to:

- a first aeraulic device (21) configured to treat the incoming nonmetallic fraction of smaller size range, to separate the heavy fraction to be sent to a nonmetallic residue containment vessel (13) from the light fraction to be sent to a light fraction containment vessel (15);

- a crusher/mill (22a) configured to treat the incoming nonmetallic fraction of intermediate and larger size range, said crusher/mill (22a) having, downstream, a third screening device (22b) designed to send the rejected oversize fraction to a second aeraulic device (22) and the accepted screened fraction to an induction separator (23); said second aeraulic device (22) being configured to send the light fraction to a light fraction containment vessel (15) and the heavy fraction to an induction separator (24) in turn configured to send the metal fraction to a nonferrous metal residue containment vessel (14) and the nonmetallic fraction to an optical selector (25) configured to convey the nonmetallic residues to a mineral residue containment vessel (16) and the nonferrous metal residues to a nonferrous metal residue containment vessel (15), a third aeraulic device (26) being provided which is configured to treat the incoming nonmetallic fraction of larger size range and is provided, upstream, with a manual separation station (26a), said third aeraulic device (26) being configured to separate the light fraction, to be sent to a light fraction containment vessel (15), from the heavy fraction, to be sent to a nonmetallic residue containment vessel (13).

2. The apparatus (1) according to claim 1, characterized in that it comprises, between said first magnetic separation elements (4a', 4b', etc.) and said second magnetic separation elements (4a', 4b', etc.) and said ferrous residue containment vessel (11), an additional extraction-type magnetic separator (41) to which the magnetic fractions separated at said first magnetic separation elements (4a', 4b', etc.) and at said second magnetic separation elements (4a", 4b", etc.) are conveyed, said additional magnetic separator (41) being configured to send any ferrous material refined by said magnetic separation devices (4a, 4b, 4c, etc.) deployed upstream to a ferrous residue containment vessel (11) and the nonferrous material to a third screening device (41a).

3. The apparatus (1) according to one or more of the preceding claims, characterized in that said third screening device (41a) is configured to send the accepted screened fraction to a leachate containment vessel (17) and the rejected oversize fraction to a second crusher/mill (41b) adapted to crush/shred the larger partially magnetic material to send the shredded material back to said ribbon for loading the hopper (2).

4. The apparatus (1) according to one or more of the preceding claims, characterized in that said ballistic separator (6) comprises at least two rotating drums, each one provided with a plurality of beating vanes arranged around the respective lateral surface to intercept the particles fed to said ballistic separator (6) during their free fall toward the respective rotating drum.

5. The apparatus (1) according to one or more of the preceding claims, characterized in that said shredders comprise respective hammer mills which have a base body made of metal covered with wear-protection plates, a rotor comprising a central shaft made of tempered steel, and steel wearprotection discs housing hammer supporting shafts, said rotor rotating on command on a horizontal axis, said hammers, being coupled by means of said shafts, exiting by centrifugal force from their respective seats to determine the crushing of material passing between an anvil and grates below.

6. The apparatus (1) according to one or more of the preceding claims, characterized in that said non-ferrous material separating devices comprise respective eddy current separators ECS comprising a conveyor belt associated, at one end thereof, with a magnetic rotor induction roller configured to generate a magnetic field so that the nonferrous material arriving proximately to said magnetic field is lifted from said conveyor belt and removed, while the inert materials are conveyed separately to a mineral residue containment vessel (16).

7. The apparatus (1) according to one or more of the preceding claims, characterized in that said aeraulic devices comprise a zigzag aeraulic separator configured to remove the light fraction of heterogeneous materials by means of a countercurrent air flow inside a zigzag duct, the heavy fraction, in bouncing off the "steps" of the duct, separating from the light fraction, which is aspirated, while the heavy fraction falls directly into the lower part of the duct.

8. A method for treating and recovering ash from an incinerator or waste-to-energy plant, comprising:

- a step of loading said ash into at least one loading hopper (2) adapted to receive wet ash to be treated;

- a step of feeding the ash contained in said loading hopper (2) into a first screening device (3) configured to dimensionally separate said ash;

- a step of sending said ash arriving from said loading hopper (2), depending on the size range, to respective magnetic separation devices (4a, 4b, 4c, etc.);

- said sending step comprising sending the smaller fractions to at least one first magnetic separation element (4a', 4b') downstream of which there are, in sequence, a respective second screening device (5) for the material not intercepted as magnetic by said first magnetic separation element (4a', 4b'), said second screening device (5) being configured to send the larger size ranges to the respective second magnetic separation elements (4a", 4b") and the smaller size ranges to a ballistic separator (6);

- a step of ballistic separation of the smaller size ranges sent to said ballistic separator (6), comprising a step of sending the light fraction to a fine fraction containment vessel (12) and the heavy fraction to a first nonferrous metal separator (7) configured to separate nonferrous metals from nonmetallic residues;

- a step of conveying said nonmetallic residues arriving from said first nonferrous metal separator (7) to a nonmetallic residue containment vessel (13);

- a step of conveying the nonferrous metal residues arriving from said first nonferrous metal separator (7) to a nonferrous metal residue containment vessel (14);

- a step of sending the nonmagnetic material arriving from said magnetic separation devices (4a, 4b, etc.) to a second nonferrous metal separator (8);

- a step of sending said nonferrous metals arriving from said second nonferrous materials separator (8) to a nonferrous metal containment vessel (14);

- a step of sending the nonmetallic fraction arriving from said second nonferrous materials separator (8), depending on the size range, to:

- a crusher/mill (22a) configured to treat the incoming nonmetallic fraction of intermediate and larger size range, said crusher/mill (22a) having, downstream, a third screening device (22b) designed to send the rejected oversize fraction to a second aeraulic device (22) and the accepted screened fraction to an induction separator (23); said second aeraulic device (22) being configured to send the light fraction to a light fraction containment vessel (15) and the heavy fraction to an induction separator (24) in turn configured to send the metal fraction to a nonferrous metal residue containment vessel (14) and the nonmetallic fraction to an optical selector (25) configured to convey the nonmetallic residues to a mineral residue containment vessel (16) and the nonferrous metal residues to a nonferrous metal residue containment vessel (15), said induction separator (23) instead being configured to convey the metal fraction to a nonferrous metal containment vessel (14) and the nonmetallic fraction to a mineral residue containment vessel (16), a third aeraulic device (26) being configured to treat the incoming nonmetallic fraction of larger size range and having, upstream, a manual separation station (26a), said third aeraulic device (26) being configured to separate the light fraction, to be sent to a light fraction containment vessel (15), from the heavy fraction, to be sent to a nonmetallic residue containment vessel (13).

9. The method according to claim 8, characterized in that it comprises a step of sending the material not intercepted by said second magnetic separation elements (4a", 4b", etc.) to an additional magnetic separator (41) configured to send the ferrous material not intercepted by said magnetic separation devices (4a, 4b, 4c, etc.) to a ferrous residue containment vessel (11) and the nonferrous material to a third screening device (41a);

- a step of sending the smaller fraction of the material arriving from said third screening device (41a) to a sludge containment vessel (17); - a step of sending the larger fraction of the material arriving from said third screening device (41a) to a second crusher/mill (41b) adapted to shred said larger nonferrous material in order to send the shredded material to said first screening device (3).