Method and equipment for the treatment of metal scrap

Abstract

The invention relates to a method for the treatment of metal scrap comprising the following steps: - providing a device (100) comprising a friction chamber (102), the friction chamber (102) having an inlet (106) and an eccentric wheel (120) rotating in the friction chamber (102) about a horizontal axis (D), - supplying metal scrap to the inlet (106) of the friction chamber (102), - processing the metal scrap in the friction chamber (102), by rotation of the eccentric wheel (120), the rotating eccentric wheel (120) applying friction forces to the metal scrap, and - discharging the processed metal scrap. The invention further relates to an associated equipment.

Description

[0001] Method and equipment for the treatment of metal scrap

[0002] The present invention concerns a method for the treatment of metal scrap, in particular shredded steel scrap.

[0003] The invention further relates to an associated equipment.

[0004] Nowadays steel scrap is commonly used in steelmaking process for the production of liquid steel. Said scrap may be used at different stages along the steelmaking process and in different steelmaking tools. Converter, Basic Oxygen Furnace (BOF), Electric Arc Furnace (EAF) are some of the tools, which may notably be used for steelmaking production.

[0005] In order to reduce CO2 global footprint of the steelmaking process, there is a global trend to use more and more scrap into steel production. However, said scrap may be of different kind, depending notably on their origin, and thus have different qualities in terms notably of shape, density, chemistry and presence of impurities. This quality has an impact on the subsequent steel production steps. Steel scrap is classified in three main categories namely home scrap, new scrap, and old scrap depending on when it becomes scrap in its life cycle.

[0006] Home scrap is the internally generated scrap during the manufacturing of the new steel products in the steel plants. This form of scrap rarely leaves the steel plant production area. Instead, it is returned to the steelmaking furnace on site and melted again. This scrap has known physical properties and chemical composition.

[0007] New scrap (also called prime or industrial scrap) is generated from manufacturing units, which are involved in the fabricating and making of steel products. Scrap accumulates when steel is cut, drawn, extruded, or machined. The supply of new scrap is a function of industrial activity. When activity is high, more quantity of new scrap is generated. The chemical composition and physical characteristics of new scrap is well known. This scrap is typically clean, meaning that it is not mixed with other materials. In principle, new scrap does not need any major pre-treatment process before it is melted, although cutting to size may be necessary.

[0008] Old scrap is also known as post-consumer scrap or obsolete scrap. It is steel that has been discarded when industrial and consumer steel products (such as automobiles, appliances, machinery, buildings, bridges, ships, cans, and railway coaches and wagons etc.) have served their useful life. Old scrap is collected after a consumer cycle, either separately or mixed, and it is often contaminated to a certain degree, depending highly on its origin and the collection systems. Since the lifetime of many products can be more than ten years and sometimes even more than fifty years (for example products of building and construction), there is an accumulation of iron and steel products in use since the production of the steel has started on a large scale. Since the old scrap is often material that has been in use for years or decades, chemical composition and physical characteristics are not usually well known. It is also often mixed with other trash.

[0009] In order to reduce the global footprint of produced steel, those old or obsolete scrap must be recycled to be used into the steelmaking process. As mentioned above, those scrap have various qualities in terms of chemical composition or physical properties, and may then have detrimental impact on the steel to be produced. They may for example contain unwanted materials, such as contaminants, dirt, coatings, or non-metallic materials that interfere with the desired chemical composition or physical properties of the final product and must therefore be eliminated or separated from the metallic feedstock before processing.

[0010] There is thus a need for a method and a device allowing to use more and more obsolete scrap without impairing the quality of the steel to be produced.

[0011] To that end, the invention relates to a method for the treatment of metal scrap comprising the following steps:

[0012] - providing a device comprising a friction chamber, the friction chamber having an inlet and an eccentric wheel rotating in the friction chamber about a horizontal axis,

[0013] - supplying metal scrap to the inlet of the friction chamber,

[0014] - processing the metal scrap in the friction chamber, by rotation of the eccentric wheel, the rotating eccentric wheel applying friction forces to the metal scrap, and

[0015] - discharging the processed metal scrap.

[0016] The processing of the metal scrap in the friction chamber allows separating different materials that are, for example, entangled in the metal scrap. Thus, the different materials may be sorted, such as to be reused according to their nature. Further, the resulting scrap is of better quality and densified. The method according to the invention thus allow to separate metal from unwanted materials in an efficient way through friction.

[0017] According to specific embodiments of the invention, the method also has one or more of the following features, considered alone or according to any technically possible combination(s): the metal scrap is shredded steel scrap; at least 95% of the elements composing the metal scrap have dimensions, in any direction, inferior or equal to 0.20 m, the rest of the elements having preferably dimensions, in any direction, inferior or equal to 1.0 m; the metal scrap has a material density ranging from 0.6 to 0.9 ton / m3; the friction chamber comprises a bottom, the eccentric wheel comprises an edge, such that, during rotation of the eccentric wheel, a shortest distance measured between the edge of the eccentric wheel and the bottom vary between a minimal distance and a maximal distance; during rotation of the eccentric wheel, the minimal distance between the edge of the eccentric wheel and the bottom is at least 0.2 m; during the processing in the friction chamber, metallic components of the metal scrap are separated from unwanted materials, said unwanted materials comprising at least one of dirt, coatings or non metallic materials; the friction chamber comprises an outlet, the discharging of the processed scrap from the friction chamber being performed through the outlet; the friction chamber comprises a bottom, the outlet being provided at the bottom of the friction chamber; the outlet is movable between a closed configuration, where it prevents the processed scrap from leaving the friction chamber, and an open configuration, where it allows discharging the processed scrap from the friction chamber; the device comprises a dust collection system, the friction chamber being provided with a dust outlet in an upper portion of the friction chamber, the dust collection system being connected to the dust outlet; the supplied metal scrap is previously sorted using a vibratory screener feeder, the vibratory screener feeder elements that are smaller than a screening dimension, from the elements that are bigger than said screening dimension, such that the smaller elements are not supplied to the inlet; the method comprises the further step of magnetic sorting of the processed scrap; and / or the method further comprises sorting the magnetic processed scrap using a densiometric screen, and / or sorting the non-magnetic processed scrap using an Eddy current separator; during the processing the metal scrap in the friction chamber, the elements of the metal scrap are not subjected to any substantial size reduction.

[0018] The invention further relates to an equipment for treating metal scrap, comprising a device comprising a friction chamber, the friction chamber having an inlet for metal scrap, the device comprising an eccentric wheel adapted to rotate in the friction chamber about a horizontal axis, such as to process the metal scrap in the friction chamber. The equipment allows separating metal scrap from unwanted materials, such as dirt, non-metallic materials, paint residues, etc. Other features and advantages of the invention will appear upon reading the following description, provided solely as an example and done in reference to the appended drawings, in which:

[0019] Figure 1 is a schematic view of steps of a method according to an example of the invention,

[0020] Figure 2 is a schematic view of an equipment according to an example of the invention,

[0021] Figure 3 is a schematic view of steps of method according to an example of the invention, and

[0022] Figure 4 is a representation with photos of steel scrap before and after applying a treatment method according to the invention.

[0023] The invention relates, in regards to figure 1 , to a method 10 for the treatment of metal scrap, comprising the following steps:

[0024] - providing a device 12,

[0025] - supplying metal scrap 14,

[0026] - processing the metal scrap 16, and

[0027] - discharging the processed metal scrap 18.

[0028] The metal scrap is, for example, shredded steel scrap.

[0029] The shredded steel scrap is for example obtained from steel scrap that has already undergone a mechanical size-reduction process, such as shredding, crushing, or fragmenting, so as to produce smaller pieces.

[0030] At least 95% of the elements composing the metal scrap have dimensions, in any direction, inferior or equal to 0.20 m. The rest of the elements, if so, have dimensions, in any direction, inferior or equal to 1 .0 m.

[0031] The metal scrap is, for example, E40 and / or E46 shredded ferrous steel scrap according to Ell-27 steel scrap specification, last update of May 2007.

[0032] The metal scrap, for example, has a material density from 0.6 to 0.9 ton / m3.

[0033] An example of the provided device 100 is represented in figure 2.

[0034] The device 100 comprises a friction chamber 102.

[0035] The friction chamber 102 delimits an inner volume 104.

[0036] The friction chamber 102 is provided with an inlet 106, and optionally with an outlet 108.

[0037] The friction chamber 102 is, for example, further provided with a dust outlet 110.

[0038] The inner volume 104 is closed apart from the inlet 106, and if so the outlet 108 and / or the dust outlet 110. The friction chamber 102 comprises a bottom 112.

[0039] The friction chamber 102 is, for example, a rectangular cuboid apart from the bottom

[0040] 112.

[0041] The bottom 112 is, for example, arched, such that the friction chamber 102 is convex at the bottom 112.

[0042] The inlet 106 is, for example, provided at the top of the friction chamber 102.

[0043] In particular, the inlet 106 is, for example, provided in an upper surface of the friction chamber 102, more particularly centered in the upper surface.

[0044] The inlet 106 is fed from a feeding chamber 114 of the device.

[0045] The feeding chamber 114 is arranged above the friction chamber 102 according to a direction of elevation Z, in particular on the friction chamber 102.

[0046] The inlet 106 is controllable between a closed configuration, where it prevents the metal scrap from entering the friction chamber 102, and an open configuration, where it allows the passage of the metal scrap into the friction chamber 102.

[0047] The outlet 108 is provided at the bottom of the friction chamber 102, in particular at the lowest point of the friction chamber according to the direction of elevation Z.

[0048] The outlet 108 is arranged opposite the inlet 106 along the direction of elevation Z.

[0049] The outlet 108 is movable between a closed configuration, where it prevents the processed scrap from leaving the friction chamber 102, and an open configuration, where it allows discharging the processed scrap from the friction chamber 102.

[0050] The outlet 108 is here provided with a hatch 116 movable between the closed configuration (in solid lines in figure 2) and the open configuration (in dotted lines in figure 2).

[0051] The outlet 108 is adapted to discharge the processed scrap from the friction chamber 102 to a discharge container 118.

[0052] The discharge container 118 is arranged below the outlet 108 along the direction of elevation Z.

[0053] Thus, the scrap processed in the friction chamber, as described below, and discharged through the outlet 108 is received in the discharge container 118.

[0054] The dust outlet 110 is arranged in an upper portion of the friction chamber 102, in particular in the upper half of the friction chamber along the direction of elevation Z.

[0055] The dust outlet 110 is here arranged in a lateral surface of the friction chamber, more particularly adjacent to the upper edge of the lateral surface.

[0056] Thus, the scrap processed in the friction chamber 102, apart from volatile material, such as dust, does not leave the inner volume 104 through the dust outlet 110.

[0057] The device 100 comprises an eccentric wheel 120. The eccentric wheel 120 is adapted to rotate in the friction chamber 102 about an axis of rotation D.

[0058] The axis of rotation D is fixed in the friction chamber 102.

[0059] The axis of rotation D is horizontal, i.e. perpendicular to the direction of elevation Z.

[0060] In particular, the eccentric wheel 120 is driven by a motor 124.

[0061] The eccentric wheel 120, in particular a shaft at the axis of rotation D, is here linked to a rotor of the motor by a belt 126.

[0062] The eccentric wheel 120 is here a cam.

[0063] The eccentric wheel 120 has for example a constant thickness measured parallel to the axis of rotation D.

[0064] The thickness of the wheel 120 is such as to ensure mechanical robustness of the assembly by guaranteeing the continuous circumferential flow of the material around the wheel once it fills the friction chamber 102.

[0065] The eccentric wheel 120 has the shape of a right cylinder with an eccentric base.

[0066] The eccentric wheel comprises an edge 122.

[0067] The edge 122 is parallel to the axis of rotation D.

[0068] The edge 122 is for example the lateral surface of the cylinder.

[0069] During rotation of the eccentric wheel 120, metal scrap is processed within the friction chamber 102, so that the eccentric wheel 120 causes friction, compression and expansion of the metal scrap, so that the materials of different ductility are separated and the bonds between different materials are broken.

[0070] In this way, the different materials constituting the metal scrap elements are disentangled by the action of the rotation of the eccentric wheel. The rotation of the eccentric wheel induces friction both between the scrap elements themselves and between the scrap and the inner surface of the friction chamber, thereby facilitating the detachment of dirt, coatings, or non-metallic materials. As a result, the metallic fractions are progressively separated from unwanted materials.

[0071] The rotation of the eccentric wheel 120 also leads to a densification of the elements forming the metal scrap.

[0072] During rotation of the eccentric wheel 120, the edge 122 of the eccentric wheel and the bottom 112 are at a minimal distance at a given moment, the minimal distance allowing material to flow between the edge 122 of the eccentric wheel and the bottom 112. For example, the minimal distance is superior to 0.2 m.

[0073] During rotation of the eccentric wheel, the edge 122 of the eccentric wheel and the bottom 112 are at a maximal distance at a given moment. The maximal distance is, for example, such that it allows having sufficient capacity in the friction chamber 102. For example, the maximal distance is such that the friction chamber 102 may process from 5000 to 10000 kg of material in the friction chamber in one batch.

[0074] Thus, during rotation of the eccentric wheel, the distance between the edge 122 of the eccentric wheel and the bottom 112 varies between the above minimal distance and the above maximal distance.

[0075] Due to the narrow space between the edge 122 of the eccentric wheel and the bottom 112 of the friction chamber 102 and the fact that the material is forced to go through that narrow space in a continuous material flow; the material is becoming increasingly dense, up to a certain density due to the compression forces applied in that narrow space.

[0076] This densification is here obtained mainly because of the rounding of the material.

[0077] During this process, the metal scrap elements are not subjected to any substantial size reduction, for example by cutting. By “substantial”, we mean that the elements are subjected to a size reduction of at most 10%, preferably at most 5%.

[0078] The action of the rotating wheel primarily serves to disentangle and separate the materials rather than to fragment the scrap.

[0079] In a particular embodiment, the eccentric wheel 120 is removable, such as to allow its replacement by another eccentric wheel.

[0080] This allows changing the eccentric wheel, in particular to be able to process metal scrap with different properties.

[0081] In a particular embodiment, the pitch of the eccentric wheel is adjustable. The pitch of the eccentric wheel may for example be modified to adapt to the material dimensions, to ensure efficiency.

[0082] The friction chamber 102 and the eccentric wheel 120 are preferably made of a material that resists to abrasion, such as AR500 steel, ceramic material or zirconia alumina.

[0083] Advantageously, the device 100 comprises deflectors (not shown) arranged within the friction chamber 102, on walls of the chamber, in order to deflect scrap from said walls and limit the wear of the friction chamber 102 by the scrap. Preferably, the deflectors are arranged in the friction chamber 102 in such a manner that the material flow movement inside the friction chamber 102 is optimized.

[0084] The deflectors are for example made of a consumable material, for example steel or ceramic plates. The deflectors are for example destined to be replaced regularly.

[0085] The device 100 here further comprises a vibratory screener feeder 130. The vibratory screener feeder 130 is adapted to separate elements that are smaller than a screening dimension, called fines, from the elements that are bigger than said screening dimension.

[0086] Said screening dimension is, for example, comprised from 10 mm to 20mm, for example equal to 10mm.

[0087] The bigger elements are provided to a discharge 132 of the feeder 130.

[0088] In one embodiment, the device 100 further comprises a system downstream the vibratory screener feeder 130 and upstream the inlet 106, in particular at the discharge 132, to discard elements that are bigger than a maximum dimension, for example 0.30 m. Thus, the scrap elements provided by the vibratory screener feeder have dimensions between the screening dimension and the maximum dimension.

[0089] The scrap elements are provided to the inlet 106 of the friction chamber 102.

[0090] More particularly, the discharge 132 is connected to the inlet chamber 114 by a conveyor belt 134.

[0091] The conveyor belt 134 is adapted to convey the scrap elements from the discharge 132 to the feeding chamber 114.

[0092] Here, the device 100 further comprises a dust collection system 136.

[0093] The dust collection system 136 is connected to the dust outlet 110.

[0094] The dust collection system 136 comprises an air suction system, adapted to suck the air at the dust outlet 110, to assist the collection of dust, produced by the processing of the metal scrap inside the friction chamber 102.

[0095] Here, the device 100 further comprises a control unit 138.

[0096] The control unit 138 is adapted to control the configuration of the inlet 106 and the configuration of the outlet 108.

[0097] The control unit 138 is further adapted to control the rotation of the eccentric wheel 120, in particular to control the motor 124.

[0098] In the method of the invention of figure 1 , the metal scrap is supplied to the inlet 106 of the friction chamber 102.

[0099] Advantageously, the metal scrap is shredded steel scrap, and the method comprises a preliminary step of shredding steel scrap.

[0100] The metal scrap is, for example, previously sorted using the vibratory screener feeder 130 and conveyed to the feeding chamber 114, here via the conveyor belt 134.

[0101] The inlet 106 is moved into the open configuration, to allow the introduction of metal scrap inside the inner volume 104.

[0102] The outlet 108 is in the closed configuration. The metal scrap introduced inside the inner volume 104 has a density of at least 0.6 ton per cubic meter, for example ranging from 0.6 to 0.9 ton per cubic meter.

[0103] After the introduction of the metal scrap, the inlet 106 is moved into the closed configuration.

[0104] The metal scrap is then processed in the friction chamber 102, by rotation of the eccentric wheel 120.

[0105] The rotating eccentric wheel 120 provides friction forces within the metal scrap.

[0106] As described previously, the different materials forming the elements of the metal scrap are disentangled by the action of the rotation of the eccentric wheel.

[0107] During this operation, the elements of the metal scrap remain essentially intact in size.

[0108] Further, the elements of the metal scrap are densified.

[0109] Then, the processed scrap is discharged from the friction chamber 102 through the outlet 108.

[0110] More precisely, the outlet 108 is moved into the open configuration. Here, the hatch 116 is opened.

[0111] The processed scrap is, for example, discharged in the discharge container 118.

[0112] Another cycle of processing of metal scrap may then be started, using new metal scrap from the feeding chamber 114.

[0113] A method 200 of treatment, with additional steps, is described in relation to figure 3 according to an example of the invention.

[0114] The method 200, for example, comprises a preliminary step 202 of sorting the metal scrap according to the dimensions of the elements, for example using a vibratory screener feeder, as described previously.

[0115] At the end of step 202, some elements of the metal scrap are selected, based on the previous sorting.

[0116] The selected sorted elements have dimensions superior to a screening dimension.

[0117] In one embodiment, the selected sorted elements have dimensions inferior to a maximum dimension.

[0118] The selected sorted elements of the metal scrap are then fed to a friction chamber, as described previously.

[0119] The selected sorted elements of the metal scrap are then processed 204 according to the steps described in relation with figure 1 .

[0120] The method then comprises a step of magnetic sorting 206 of the processed scrap.

[0121] Magnetic sorting separates magnetic from nonmagnetic elements. More particularly, the processed scrap collected from the outlet 108, in particular in the discharge container 118, is sorted using magnetic properties of the element, for example using permanent magnet(s) and / or electro-magnet(s) and / or a magnetic overband.

[0122] For example, iron Fe is firstly separated from the rest of the scrap, and then the stainless steel is separated from the remaining material.

[0123] The method then comprises sorting the magnetic processed scrap using a densiometric screen 208, and / or (here and) sorting the non-magnetic processed scrap using an Eddy current separator 210.

[0124] Thanks to the processing, the elements are no longer entangled and are thus effectively sorted.

[0125] The densiometric screen is here adapted to separate the magnetic processed scrap in a plurality of categories depending on the size and density of the elements.

[0126] For example, the densiometric screen is adapted to separate the magnetic processed scrap in three size categories: scrap having a dimension superior or equal to a given dimension, e.g. 40 mm, scrap having a dimension inferior to the given dimension, and fines.

[0127] The scrap having a dimension superior or equal to the given dimension is a high quality scrap, the scrap having a dimension inferior to the given dimension being a reduced size scrap.

[0128] Both scraps are, for example, reused to produce steel using an electric arc furnace.

[0129] Each category is identified, such that the producing method may be adapted depending on the properties of the corresponding scrap.

[0130] The densiometric screen is further adapted to separate the magnetic processed scrap in different density categories, for example, so-called heavy metals (such as Cu, Zn, Inox, Pb, Ti ...), so-called light metals (Al and Zn), so-called heavy No-metals (such as glass, stones ...) and so-called might No-metals, such as polymeric materials.

[0131] The method further comprises a step of briquetting the fines.

[0132] In this step, the fines are compacted under pressure, optionally with the addition of a binder, to form briquettes or agglomerates of predetermined size and density.

[0133] The briquetting step allows a beneficiation of the fines by transforming said fines into a usable raw material. Said raw material can be stored, transported, and charged into metallurgical furnaces, thereby reducing material losses and improving overall process efficiency

[0134] The Eddy current separator is here adapted to separate the non-magnetic processed scrap into different categories depending on the nature of the material of each element.

[0135] The different categories, for example, include the following categories: non magnetic metal (such as copper, aluminum and chromium), rubber and plastics, and steriles. The non magnetic metal are, for example, sold for further use. They can, for example, be used as raw material in secondary metallurgy process.

[0136] The rubber and plastics are, for example, processed in the electric arc furnace, for example as a substitute of carbon.

[0137] The method, for example, further comprises a step 212 of magnetic sorting of the elements having dimensions inferior to the screening dimension in step 202.

[0138] The magnetic elements obtained in step 212 are, for example, briquetted.

[0139] The method further comprises sorting the non-magnetic elements obtained in step 212 using an Eddy current separator.

[0140] In the depicted embodiment, the non-magnetic elements obtained in step 212 are, for example, sorted with the non-magnetic elements obtained after step 206.

[0141] In another embodiment, they are sorted separately, for example using different Eddy current separators and / or at different moments.

[0142] The invention also relates to the equipment for treating metal scrap.

[0143] The equipment comprises a device as described previously.

[0144] The equipment, for example, further comprises means for magnetic sorting as described regarding steps 206, 212, an Eddy current separator as described in regard to step 210 and / or a densiometric screen as described in regard to step 208.

[0145] Figure 4 shows a picture of a first batch of shredded steel scrap (Batch 1) before treatment on the left and the resulting sorted categories on the right.

[0146] Batch 1 was treated according to the steps 202, 204, 206, 208, and 212 of the method described in regard to figure 3.

[0147] Batch 1 provided 44% of treated shredded scrap, 3% of magnetic fraction with a dimension inferior to 40 mm that are not fines, 32% of magnetic fines and 5% of nonmagnetic fraction.

[0148] The non-magnetic fraction may then be sorted using an Eddy current separator, as described in regard to step 210.

[0149] Each category may then be valued as most appropriate. In particular, the treated shredded scrap and the magnetic fraction are for example used in an electric arc furnace for the production of steel (separately or together depending on the specifications wanted for the production of steel), and the magnetic fines are revalued by briquetting.

[0150] Furthermore, the chemical composition of Batch 1 was analyzed before treatment, as well as the chemical composition of the composition of the treated shredded scrap obtained, and the following results were obtained:

[0151] There is a clear improvement in the chemical composition, in particular in regard to Fe and Cu, but also in material metallic yield. A second batch of different scrap (Batch 2) was also treated according to the steps

[0152] 202, 204, 206, 208, and 212 of the method described in regard to figure 3

[0153] Batch 2 provided 88% of treated shredded scrap, 2% of magnetic fraction with a dimension inferior to 40 mm that are not fines, 2% of magnetic fines and 4% of non-magnetic fraction. The non-magnetic fraction may then be sorted using an Eddy current separator, as described in regard to step 210.

[0154] Each category may then be valued as most appropriate, as described previously.

[0155] The chemical composition of the batch 2 was analyzed before treatment, as well as the chemical composition of the treated shredded crap and the magnetic fines obtained after treatment, and the following results were obtained: There is a clear improvement in the chemical composition of the shredded scrap, in particular in regard to Fe and Cu, but also in material metallic yield.

[0156] Thus, the method of the invention allows improving the quality of the scrap grades, in addition to allowing the valorization of each category of material as most appropriate.

Claims

CLAIMS1.- A method for the treatment of metal scrap comprising the following steps:- providing (12) a device (100) comprising a friction chamber (102), the friction chamber (102) having an inlet (106) and an eccentric wheel (120) rotating in the friction chamber (102) about a horizontal axis (D),- supplying (14) metal scrap to the inlet (106) of the friction chamber (102),- processing (16) the metal scrap in the friction chamber (102), by rotation of the eccentric wheel (120), the rotating eccentric wheel (120) applying friction forces to the metal scrap, and- discharging the processed metal scrap.2.- Method according to claim 1 , wherein the metal scrap is shredded steel scrap.3.- Method according to claim 2, wherein at least 95% of the elements composing the metal scrap have dimensions, in any direction, inferior or equal to 0.20 m, the rest of the elements having preferably dimensions, in any direction, inferior or equal to 1 .0 m.4.- Method according to any one of claims 1 to 3, wherein the metal scrap has a material density ranging from 0.6 to 0.9 ton / m3.5.- Method according to any one of claims 1 to 4, wherein, during the processing (16) in the friction chamber (102), metallic components of the metal scrap are separated from unwanted materials, said unwanted materials comprising at least one of dirt, coatings or non metallic materials.6.- Method according to any one of claims 1 to 5, wherein the friction chamber (102) comprises a bottom (112), the eccentric wheel (120) comprises an edge (122), such that, during rotation of the eccentric wheel (120), a shortest distance measured between the edge (122) of the eccentric wheel (120) and the bottom (112) vary between a minimal distance and a maximal distance.7.- Method according to claim 6, wherein, during rotation of the eccentric wheel (120), the minimal distance between the edge (122) of the eccentric wheel (120) and the bottom (112) is at least 0.2 m.8.- Method according to any one of claims 1 to 7, wherein the friction chamber (102) comprises an outlet (108), the discharging of the processed scrap from the friction chamber (102) being performed through the outlet (108).9.- Method according to claim 8, wherein the friction chamber (102) comprises a bottom (112), the outlet (108) being provided at the bottom (112) of the friction chamber (102).10.- Method according to claim 9, wherein the outlet (108) is movable between a closed configuration, where it prevents the processed scrap from leaving the friction chamber (102), and an open configuration, where it allows discharging the processed scrap from the friction chamber (102).11.- Method according to any one of claims 1 to 10, wherein the device (100) comprises a dust collection system (136), the friction chamber (102) being provided with a dust outlet (110) in an upper portion of the friction chamber (102), the dust collection system (136) being connected to the dust outlet (110).12.- Method according to any one of claims 1 to 11 , wherein the supplied metal scrap is previously sorted using a vibratory screener feeder (130), the vibratory screener feeder (130) elements that are smaller than a screening dimension, from the elements that are bigger than said screening dimension, such that the smaller elements are not supplied to the inlet.13.- Method according to any one of claims 1 to 12, comprising the further step of magnetic sorting of the processed scrap.14.- Method according to claim 13, further comprising sorting the magnetic processed scrap using a densiometric screen (206), and / or sorting the non-magnetic processed scrap using an Eddy current separator (210).15.- Method according to any one of claims 1 to 14, wherein during the processing (16) the metal scrap in the friction chamber (102), the elements of the metal scrap are not subjected to any substantial size reduction.16.- Equipment for treating metal scrap, comprising a device (100) comprising a friction chamber (102), the friction chamber (102) having an inlet (106) for metal scrap, the device (100) comprising an eccentric wheel (120) adapted to rotate in the friction chamber (102) about a horizontal axis (D), such as to process the metal scrap in the friction chamber (102).

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