System and method for separating fine metal particles from the top gas of a metallurgical furnace, and metallurgical furnace for producing pig iron and separating fine metal particles

Abstract

The present invention relates to a system for separating fine metal particles from the top gas of a metallurgical furnace (20), comprising: at least one gas transport pipe (10) configured to convey the top gas out of the metallurgical furnace (20); at least one coarse particle separator (11) for separating coarse particles from the top gas; at least one first collection tank (12) coupled downstream of the at least one coarse particle separator (11); at least one fine particle separator (13) for separating fine metal particles from the top gas; and at least one second collection tank (14) coupled downstream of the at least one fine particle separator (13), the at least one second collection tank (14) being configured to receive a slurry comprising the fine metal particles separated from the top gas; wherein the at least one gas transport pipe (10) forms a downstream connection between the metallurgical furnace (20), the at least one coarse particle separator (11) and the at least one fine particle separator (13). The invention also relates to a method for separating fine metal particles from the top gas of a metallurgical furnace (20), as well as to a metallurgical furnace (20) for producing pig iron and separating fine metal particles.

Description

SYSTEM AND METHOD FOR SEPARATING FINE METAL PARTICLES FROM A TOP GAS OF A STEEL FURNACE, AND STEEL FURNACE FOR MANUFACTURING PIG IRON AND SEPARATION OF FINE METAL PARTICLES TECHNICAL FIELD

[0001] The present invention relates to a system and method applied to steelmaking. Specifically, the present invention relates to a system and method for manufacturing pig iron and fine metal particles. FUNDAMENTALS

[0002] Fine metal particles, such as metal particles comprising essentially zinc particles, are particularly problematic for the operation of steel furnaces and blast furnaces in the production of pig iron. State-of-the-art steel furnaces generally have a load limiting control for these fine metal particles, so as to avoid a recirculation flow within the furnace between a vapor and condensate state that is detrimental to the operation of the steel furnace.

[0003] Some steel furnaces have operating temperatures that allow some of these particles to be volatilized. In these furnaces, these particles evaporate in hotter regions, but as soon as the vapors from these fine metal particles come into contact with cooler / higher regions, the fine metal particles begin to condense and settle on the cold surface. An example of a colder region of the furnace is its top; state-of-the-art steel furnaces generally have a top temperature of around 150 °C, which is too low to volatilize the fine metal particles. As a result, the maximum zinc content accepted in blast furnace operation is close to 150 g of zinc per ton of hot metal produced.

[0004] When fine metal particle vapors are not eliminated, the accumulation of this material on the walls of the furnace can begin to form thick layers (scab) of metal in the upper part of the furnace (where temperatures are lower).

[0005] This process means that the steel furnace has to be frequently interrupted, which is unfeasible for the reactor's productivity.

[0006] Among the known solutions for pig iron production, patent document BR 10 2013 033702 1 Bl describes a metallurgical furnace capable of operating with a wide range of raw materials and fuels, including those with high levels of impurities.To this end, the metallurgical furnace comprises (i) at least one upper tank, (ii) at least one lower tank, (iii) at least one fuel feeder positioned substantially between the at least one upper tank and the at least one lower tank, (iv) at least one row of tuyeres positioned in at least one of the at least one upper tank and the at least one lower tank, the at least one row of tuyeres fluidly communicating the interior of the furnace with the external environment, and (v) at least one burner positioned in at least one of the at least one upper tank and the at least one lower tank, the use of at least one burner in conjunction with the at least one row of tuyeres generates a very intense release of heat due to the exothermic reactions that occur through this combination.

[0007] Patent document BR 11 2017 012467 0 Bl describes a metallurgical furnace capable of operating with a wide range of raw materials and fuels, including those with high levels of impurities. To this end, the metallurgical furnace comprises (i) at least one upper tank, (ii) at least one lower tank, (iii) at least one fuel feeder positioned substantially between the at least one upper tank and the at least one lower tank, (iv) at least one row of tuyeres positioned in at least one of at least one upper tank and at least one lower tank, at least one row of tuyeres fluidly communicating the interior of the furnace with the external environment, (v) at least one hood called Curtain Wall located in the upper tank that extends longitudinally through the furnace, and (vi) at least one permeabilizing fuel loading system in the center of the upper tank called a booster loading system. The use of the booster loading system together with the Curtain Wall allows channeling of the gas generated in the combustion of the fuel in the lower tank with the air blown by the primary tuyeres and secondary tuyeres, controlling the gas distribution in the furnace more efficiently.

[0008] On the other hand, the production of metal alloys from fine metal particles, such as zinc particles, is commonly done using a Waelz furnace. The process that uses the Waelz furnace to concentrate zinc is a pyrometallurgical route to recover zinc from materials / co-products that contain zinc, mainly in the form of zincite (ZnO) and / or franklinite (ZnFeiC), such as electric steel mill dust. This process involves feeding the residue into a rotary kiln, where it is heated to temperatures close to 1200°C. The zinc present in the residue is reduced and reoxidized, being collected in a dust collection system.

[0009] Although the state of the art presents steel mills for the production of pig iron and the Waelz furnace as an alternative for concentrating zinc, the state of the art fails to reveal a steel mill for the production of pig iron and the separation of fine metal particles, such as zinc, simultaneously.

[0010] Furthermore, the prior art fails to disclose a system and method for separating fine metal particles from the overhead gas of a steel mill furnace that enables the recovery of fine metal particles, like zinc, from the top gas. OBJECTIVES

[0011] A first objective of the present invention is to solve this technical problem by providing a system and method for separating fine metal particles from the overhead gas of a steelmaking furnace.

[0012] A second object of the present invention is to solve this technical problem by providing a steelmaking furnace for manufacturing pig iron and separating fine metal particles.

[0013] A third object of the present invention is to provide a steelmaking furnace for manufacturing pig iron and separating fine metal particles as an alternative to the Waelz furnace.

[0014] A fourth objective of the present invention is to provide a steelmaking furnace for manufacturing pig iron and separating fine metal particles that can be fed with material rich in fine metal particles without compromising the operation of the steelmaking furnace. SUMMARY

[0015] The present invention relates to a system for separating fine metal particles from an overhead gas of a steelmaking furnace, comprising: at least one gas transport channel configured to transport the overhead gas out of the steelmaking furnace; at least one coarse particle separator element for separating coarse particles from the overhead gas; at least a first collection tank coupled downstream of the at least one coarse particle separator element; at least one fine particle separator element for separating fine metal particles from the overhead gas; and at least a second collection tank coupled downstream of the at least one fine particle separator element, wherein the at least one second collection tank is configured to receive a slurry comprising the fine metal particles separated from the overhead gas; wherein the at least one gas transport channel connects the at least one first collection tank to the at least one second collection tank. downstream of the steel furnace, at least one coarse particle separator element and at least one fine particle separator element.

[0016] The present invention further relates to a method of separating fine metal particles from an overhead gas of a steelmaking furnace, comprising: conveying the overhead gas out of the steelmaking furnace through at least one gas transport channel; separating coarse particles from the overhead gas through at least one coarse particle separator element; collecting the deposited coarse particles in at least a first collection tank coupled downstream of the at least one coarse particle separator element, separating the fine metal particles from the overhead gas through at least one fine particle separator element; and collecting a slurry comprising the fine metal particles separated from the overhead gas in at least a second collection tank coupled downstream of the at least one fine particle separator element.

[0017] The present invention is additionally related to a steelmaking furnace for manufacturing pig iron and separating fine metal particles, comprising: at least one upper tank; at least one lower tank; at least one fuel feeder positioned between the at least one upper tank and the at least one lower tank; and at least one row of tuyeres positioned in at least one of the at least one upper tank and the at least one lower tank, the at least one row of tuyeres fluidly communicating the interior of the furnace with the external environment; and at least one burner positioned in at least one of the at least one upper tank and the at least one lower tank; and a system for separating fine metal particles from a top gas of the steelmaking furnace of the present invention connected to a gas outlet of the steelmaking furnace; wherein the steelmaking furnace is fed with a plurality of solid agglomerates comprising fine metallic particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A more complete understanding of the present disclosure may be obtained by reference to the detailed description when considered in conjunction with the following illustrative Figures.

[0019] Figure 1 illustrates the system for separating fine metal particles from a steel furnace overhead gas according to an embodiment of the present invention.

[0020] Figure 2 illustrates the steelmaking furnace of the system for manufacturing pig iron and separating fine metal particles according to an embodiment of the present invention.

[0021] Figure 3 illustrates the steel furnace coupled to the system for separating fine metal particles from a top gas of a steel furnace according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention relates to a system for separating fine metal particles from an overhead gas of a steelmaking furnace 20, comprising: at least one gas transport channel 10 configured to transport the overhead gas out of the steelmaking furnace 20; at least one coarse particle separator element 11 for separating coarse particles from the overhead gas; at least a first collection tank 12 coupled downstream of the at least one coarse particle separator element 11; at least one fine particle separator element 13 for separating fine metal particles from the overhead gas; and at least a second collection tank 14 coupled downstream of the at least one fine particle separator element 13, wherein the at least one second collection tank 14 is configured to receive a slurry comprising the fine metal particles separated from the overhead gas;wherein the at least one gas transport channel 10 connects downstream the steelmaking furnace 20, the at least; a coarse particle separator element 11 and the at least one fine particle separator element 13.

[0023] The detailed description of exemplary embodiments herein refers to the accompanying drawings which show embodiments of the present invention. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosures, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein. Accordingly, the detailed description herein is presented for purposes of illustration only and not of limitation.

[0024] Figure 1 illustrates the fine metal particle separation system of the present invention. In particular, Figure 1 illustrates the at least one coarse particle separator element 11 for separating coarse particles from overhead gas, at least a first collection tank 12 coupled downstream of the at least one coarse particle separator element 11, at least one fine particle separator element 13 for separating fine metal particles from overhead gas, and at least a second collection tank 14 coupled downstream of the at least one fine particle separator element 13.

[0025] Preferably, the at least one gas transport channel 10 is coupled to the top of the steel furnace 20 to capture the gases expelled by the furnace 20 and transport them to the at least one coarse particle separator element 11.

[0026] Preferably, the at least one coarse particle separator element 11 is a cyclone. In particular, in the at least one coarse particle separator element 11, there is separation of coarse particles from the overhead gas pool and fine metal particles by vortex separation using rotational and gravitational effects. Coarse solid particles tend to hit the inner walls of the at least one coarse particle separator element and lose speed, falling to the bottom of the underflow element, where they settle in at least a first collection tank 12. The at least one first collection tank 12 is coupled downstream of the at least one coarse particle separator element 11 and is where the collection of coarse particles occurs.

[0027] On the other hand, the fine metal particles and the lighter top gas are forced upwards, by means of the formation of a negative pressure in the center of the vortex, and expelled in the upper region of the at least one coarse particle separator element 11, where they are transported by at least one gas transport channel 10 to the at least one fine particle separator element 13. It is noted that the coarse particles deposited in the at least one first collection tank 12 have a low concentration of fine metal particles, so that the gas that goes to the at least one fine particle separator element 13 remains with a high concentration of fine metal particles.

[0028] Preferably, the at least one fine particle separator element 13 is a venturi scrubber. In particular, a washing liquid is atomized inside the at least one fine particle separator element 13, wherein the washing liquid is injected to separate the fine metal particles from the overhead gas inserted into this element. Specifically, this washing liquid is responsible for capturing the fine metal particles from the overhead gas. Optionally, the washing liquid is water. The fine metal particles are separated from the overhead gas due to the phenomenon of difference in exit velocity of the gas particles and the washing liquid from inside the at least one fine particle separator element 13.

[0029] This phenomenon causes fine metal particles to be separated from the top gas in the form of sludge or mud that settles to the bottom. of at least one second collection tank 14. The at least one second collection tank 14 is coupled downstream of the at least one fine particle separator element 13. Furthermore, the at least one second collection tank 14 has a preferably prismatic and inclined bottom to allow the flow of the fine metal particle slurry and facilitate its collection.

[0030] The overhead gas is ejected from the at least one fine particle separator element 13 and falls into the at least one second collection tank 14. While the fine metal particle slurry settles at the bottom of the at least one second collection tank 14, the less dense overhead gas remains in the at least one second collection tank 14, with a phase separation occurring inside the at least one second collection tank 14 until this overhead gas is preferably forwarded to at least one demister dehumidifier 15 or for burning.

[0031] Preferably, the system of the present invention further comprises at least one demister dehumidifier 15 connected downstream of the at least one second collection tank 14 for collecting overhead gas hovering at the top of the at least one second collection tank 14 and for dehumidifying the remaining overhead gas.

[0032] Furthermore, each of the at least one dehumidifier 15 preferably comprises a metal mesh for intercepting liquid droplets in the gas and drying it. It is noted that it is possible that some of these liquid droplets comprise fine metal particles, which are captured by the metal mesh so that the dry top gas exits the at least one dehumidifier 15 and the liquid droplets comprising fine metal particles intercepted in the metal mesh fall into the at least one second collection tank 14.

[0033] Preferably, for collecting the fine metal particle sludge, at least a second collection tank 14 comprises at least one sludge drain 17, responsible for draining the sludge of fine metallic particles out of the system. This drain is facilitated by the preferably prismatic and inclined shape of the at least one second collection tank 14.

[0034] Optionally, collection may be done from an upper portion of at least a second collection tank 14, without using the sludge drain 17.

[0035] Optionally, the at least one second collection tank 14 further comprises at least one water insertion channel 16 for inserting water into the at least one second collection tank 14 for cleaning and eventual maintenance of the at least one second collection tank 14.

[0036] Preferably, due to the high outlet temperatures of the top gas from the steelmaking furnace 20, the at least one gas transport channel 10, the at least one coarse particle separator element 11, the at least one fine particle separator element 13 and the at least one demister dehumidifier 15 are internally lined with a refractory material.

[0037] Preferably, the fine metal particles are zinc particles.

[0038] The present invention further relates to a method of separating fine metal particles from an overhead gas of a steelmaking furnace 20, comprising: conveying the overhead gas out of the steelmaking furnace 20 through at least one gas transport channel 10; separating coarse particles from the overhead gas through at least one coarse particle separator element 11; collecting the deposited coarse particles in at least a first collection tank 12 coupled downstream of the at least one coarse particle separator element 11, separating the fine metal particles from the overhead gas through at least one fine particle separator element 13; and collecting a slurry comprising the fine metal particles separated from the overhead gas in at least a second collection tank 14, coupled downstream of the at least one fine particle separator element 13.

[0039] Preferably, after separating coarse particles from the overhead gas, the method of the present invention further comprises collecting the deposited coarse particles in at least one first collection tank 12 coupled downstream of the at least one coarse particle separator element 11, wherein the at least one coarse particle separator element 11 consists of a cyclone. The coarse particles are separated from the overhead gas and fine metal particles by rotational and gravitational effects from within the at least one coarse particle separator element 11. The coarse particles are deposited at the bottom of the at least one first collection tank 12, where they are collected.

[0040] Preferably, separating the fine metal particles from the overhead gas through at least one fine particle separator element 13 comprises injecting a washing liquid into the at least one fine particle separator element 13, wherein the at least one fine particle separator element 13 consists of a venturi scrubber. Optionally, the washing liquid is water. The washing liquid is responsible for capturing the fine metal particles from the overhead gas that are separated by the phenomenon of difference in exit velocity of the washing liquid, and in the size of its droplets (atomization), and from the overhead gas that occurs inside the at least one fine particle separator element 13. The fine metal particles are then deposited at the bottom of at least one second collection tank 14 in the form of slurry or mud. Preferably, the at least one second collection tank 14 being coupled downstream of the at least one fine particle separator element 13.

[0041] Preferably, the method of the present invention further comprises intercepting liquid droplets which may comprise particles fine metal particles remaining in the overhead gas through a metal mesh of at least one demister 15, wherein the at least one demister 15 is connected downstream of the at least one second collection tank 14. In addition to increasing the capture of fine metal particles, the metal mesh in this step also operates to dehumidify the overhead gas by capturing liquid droplets present in the gas. These liquid droplets comprising fine metal particles intercepted in the metal mesh fall into the at least one second collection tank 14, while the dry overhead gas is eliminated from the at least one demister 15.

[0042] Preferably, collecting a slurry comprising the fine metal particles separated from the overhead gas in at least one second collection tank 14 comprises collecting the fine metal particles through a slurry drain 17 of the at least one second collection tank 14.

[0043] Optionally, collecting a slurry comprising the fine metal particles separated from the overhead gas in at least one second collection tank 14 comprises collecting the slurry through an upper opening of the at least one second collection tank 14.

[0044] The present invention also relates to a steel furnace 20 for manufacturing pig iron and separating fine metal particles, comprising: at least one upper tank 1; at least one lower tank 2; at least one fuel feeder positioned between the at least one upper tank 1 and the at least one lower tank 2; and at least one row of tuyeres 3, 4 positioned in at least one of the at least one upper tank 1 and the at least one lower tank 2, the at least one row of tuyeres 3, 4 fluidly communicating the interior of the furnace 20 with the external environment; and at least one burner positioned in at least one of the at least one tank upper 1 and at least one lower tank 2; and a system for separating fine metal particles from a top gas of the steelmaking furnace 20 of the present invention connected to a gas outlet of the steelmaking furnace 20; wherein the steelmaking furnace 20 is fed with a plurality of solid agglomerates comprising fine metal particles.

[0045] Figure 2 illustrates the steel furnace 20 for manufacturing pig iron and separating fine metal particles, the steel furnace 20 comprising at least one upper tank 1, at least one lower tank 2 and at least one row of tuyeres 3, 4. The metallurgical furnace 20 of the present invention is essentially constituted by an upper tank 1 where the charge (raw material) is loaded into the furnace 20.

[0046] In the upper tank 1 there is a set of at least one row of secondary tuyeres 4, which are preferably holes that allow the insufflation of hot or cold atmospheric air for burning CO and other combustible gases present in the ascending gas. The insufflated air may, eventually, include O2 enrichment. In addition, gaseous, liquid or solid fuel may be injected through the tuyeres 4 together with the insufflated air.

[0047] The furnace 20 of the present invention further comprises a lower tank 2, preferably circular or rectangular in cross-section, with a diameter or dimensions sufficient for feeding solid fuel. The diameter or width of the cross-section of tank 2 is greater than that of tank 1, sufficient for positioning fuel feeders.

[0048] In the feeders, located around the junction of the upper tank 1 with the lower tank 2, fuel supply pipes 5 can be coupled to ensure the fuel load to the furnace bed, avoiding load carryover when using fine materials. As the load descends into the feeder, preheating, pre-drying and distillation of the volatile fractions present in the solid fuels occur and combustible carbonaceous waste.

[0049] Preferably, the lower tank 2 has one or more rows of primary tuyeres 3 which, like the secondary tuyeres described above, serve to blow hot or cold air, which may or may not be enriched with O2. Solid powder, liquid or gaseous fuels may also be injected for partial combustion of the fuel, producing gas and providing the thermal energy necessary for the reduction and / or fusion of the charge.

[0050] In addition, at least part of the primary or secondary tuyeres 3, 4 preferably comprise gas burners. These burners positioned in the tuyeres 4 preferably comprise a coaxial tube, i.e. a small central tube, through which the fuel is injected, and an outer tube surrounding it, through which the air blown by the tuyeres 3, 4 or any other oxidizer passes.

[0051] Thus, blown air passes through the outer tube of the burner, while fuel passes through the central tube 12. The air is then mixed with the fuel so that the mixture is burned in the region downstream of the burner, a region located inside the furnace. This ensures greater safety for the burning process, since the mixing of the fuel with the oxidizer and subsequent burning only occur inside the furnace.

[0052] The combination of air blown into tuyeres 3, 4 with the injected fuel (gas, liquid or solid) and burned in the burners generates a very intense release of heat due to the exothermic reactions that occur through this combination.

[0053] It should be noted that the steel furnace 20 of the present invention is preferably the steel furnace of patent BR102013033702-1, of the same owner, the contents of which are fully incorporated into the present description for ready reference.

[0054] Figure 3 illustrates the coupling of the separation system. fine metal particles from an overhead gas of the present invention to the steelmaking furnace 20. In addition to the steelmaking furnace 20, the at least one gas transport channel 10 connecting the furnace 20 to the at least one coarse particle separator element 11, the at least one coarse particle separator element 11 connected downstream to the at least one first collection tank 12, the at least one gas transport channel 10 further connecting the at least one coarse particle separator element 11 to the at least one fine particle separator element 13, and the at least one second collection tank 14 connected downstream to the at least one fine particle separator element 13.

[0055] The red arrows SI inside the at least one gas transport channel 10 indicate the direction of flow of gas that is expelled by the steel furnace 20. Furthermore, the red arrow S2 on the at least one coarse particle separator element 11 indicates the direction of flow of gas comprising fine particles and the arrow S3 indicates the direction of the coarse particles towards the at least one first collection tank 12. It is also possible to note the sludge drain 17 for collecting the sludge comprising fine metal particles from the at least one second collection tank 14. Finally, the clean gas, with no or little presence of fine metal particles, is eliminated from the at least one collection tank 14 for dehumidification. This clean gas is represented by the arrow S4.

[0056] Furthermore, the steelmaking furnace is fed with a metal charge (raw material) and fuel. Preferably, the metal charge is the plurality of solid agglomerates comprising fine metal particles.

[0057] Preferably, the plurality of solid agglomerates comprising fine metal particles consists of a plurality of solid agglomerates comprising electric steel mill powder. More preferably, the plurality of solid agglomerates comprising electric steel mill powder The electric steel mill consists of a plurality of briquettes comprising electric steel mill dust. Preferably, the fine metallic particles are zinc particles. It should be noted that the source of zinc in the solid agglomerate used by the present invention is not limited to electric steel mill dust; it is possible to use other sources of zinc, such as, for example, one or more of oxygen steel mill dust, willemite residues (zinc mine), steel by-products comprising zinc, or processed scrap comprising zinc. This characteristic provides the invention with the advantage of better treatment and reuse of these steel mill residues for the production of zinc.

[0058] In view of this, optionally, the plurality of solid agglomerates comprising fine metal particles of the present invention consists of a plurality of solid agglomerates comprising one or more of oxygen steelmaking dust, willemite residues, steelmaking co-products comprising zinc, or processed scrap comprising zinc.

[0059] Preferably, the steel furnace 20 is fed with a metal charge comprising self-reducing briquettes, in which the metal percentage is composed of any steel co-product that meets the minimum iron contents required for the production of pig iron according to this route. Preferably, this metal charge is reduced for the production of pig iron.

[0060] Preferably, the steel furnace 20 has a top temperature between 600 °C and 700 °C. This temperature associated with the blow flow rate of the furnace 20 allows the zinc to be eliminated from the furnace 20 in its top gas before solidifying on the internal walls of the furnace 20. It is emphasized that the blow flow rate of the furnace of the present invention is driven by the presence of at least one row of tuyeres (3, 4) and at least one burner.

[0061] Thus, the steel furnace 20 for ironmaking The system and method for separating fine metal particles from the top gas of a steelmaking furnace 20 according to the present invention are attractive because they provide a means for the simultaneous production of pig iron and zinc, being an alternative to the traditional pyrometallurgical process, which is the Waelz furnace. It is also worth noting that the Waelz furnace has as its only product the most concentrated zinc. The system, method and steelmaking furnace 20 proposed in the present invention have as their products pig iron and concentrated zinc. In addition, the steelmaking furnace 20 used by the present invention can be fed with materials with a high concentration of zinc, such as electric steelmaking dust, without the accumulation of condensed zinc on the internal walls of the furnace.This also eliminates the need for strict control of the zinc concentration of the material fed into the furnace, which is required by state-of-the-art steel furnaces to prevent the deposit of this material on their internal walls. The absence of zinc accumulation on the furnace walls 20 means that it does not require as many maintenance stops, thus not compromising its productivity.

[0062] Numerous variations affecting the scope of protection of this application are permitted. This reinforces the fact that the present invention is not limited to the particular configurations / embodiments described above.

Claims

CLAIMS 1. A system for separating fine metal particles from an overhead gas of a steelmaking furnace (20), comprising: at least one gas transport channel (10) configured to transport the overhead gas out of the steelmaking furnace (20); at least one coarse particle separator element (11) for separating coarse particles from the overhead gas; at least a first collection tank (12) coupled downstream of the at least one coarse particle separator element (11); at least one fine particle separator element (13) for separating fine metal particles from the overhead gas; and at least a second collection tank (14) coupled downstream of the at least one fine particle separator element (13), wherein the at least one second collection tank (14) is configured to receive a slurry comprising the fine metal particles separated from the overhead gas;wherein the at least one gas transport channel (10) connects downstream the steel furnace (20), the at least one coarse particle separator element (11) and the at least one fine particle separator element (13).; 2. System according to claim 1, characterized in that the at least one coarse particle separator element (11) consists of a cyclone.

3. System according to claim 1 or 2, characterized in that the at least one fine particle separator element (13) consists of a venturi washer.

4. System according to any one of claims 1 to 3, characterized in that it further comprises at least one demister dehumidifier (15) for dehumidifying the remaining overhead gas, wherein the demister dehumidifier (15) is connected downstream of the at least one second collection tank (14).

5. System, according to claim 4, characterized by the fact that each of the at least one dehumidifier (15) comprises a metal mesh to intercept liquid droplets comprising remaining fine metal particles.

6. System according to any one of claims 1 to 5, characterized in that the at least one second collection tank (14) comprises at least one sludge drain (17) and at least one water insertion channel (16).

7. System according to any one of claims 1 to 6, characterized in that the at least one second collection tank (14) has a prismatic and inclined bottom.

8. System according to any one of claims 4 to 7, characterized in that the at least one gas transport channel (10), the at least one coarse particle separator element (11), the at least one fine particle separator element (13) and the at least one demister dehumidifier (15) are internally coated with a refractory material.

9. System according to any one of claims 1 to 8, characterized in that the fine metal particles are zinc particles.

10. A method for separating fine metal particles from an overhead gas of a steelmaking furnace (20), comprising: transporting the overhead gas out of the steelmaking furnace (20) through at least one gas transport channel (10); separating coarse particles from the overhead gas through at least one at least one coarse particle separator element (11); collecting the deposited coarse particles in at least a first collection tank (12) coupled downstream of the at least one coarse particle separator element (11), separating the fine metal particles from the overhead gas through at least one fine particle separator element (13); and collecting a slurry comprising the fine metal particles separated from the overhead gas in at least a second collection tank (14) coupled downstream of the at least one fine particle separator element (13).

11. Method according to claim 10, characterized in that separating coarse particles from the overhead gas through at least one coarse particle separator element (11) comprises using rotational and gravitational effects for separating the coarse particles, wherein the at least one coarse particle separator element (11) consists of a cyclone.

12. Method according to claim 10 or 11, characterized in that separating the fine metal particles from the overhead gas through at least one fine particle separator element (13) comprises injecting a washing liquid into the at least one fine particle separator element (13), wherein the at least one fine particle separator element (13) consists of a venturi scrubber.

13. Method according to any one of claims 10 to 12, characterized in that it further comprises: intercepting liquid droplets comprising the remaining fine metallic particles in the overhead gas through a metallic mesh of at least one demister dehumidifier (15), wherein the at least one demister dehumidifier (15) is connected downstream of the at least one second collection tank (14).

14. Method according to any one of claims 10 to 13, characterized in that collecting a slurry comprising the fine metal particles separated from the overhead gas in at least one second collection tank (14) comprises collecting the fine metal particles through a slurry drain (17) of the at least one second collection tank (14), wherein the fine metal particles are zinc particles.

15. Method according to any one of claims 10 to 13, characterized in that collecting a slurry comprising the fine metal particles separated from the overhead gas in at least one second collection tank (14) comprises collecting the slurry through an upper opening of the at least one second collection tank (14), wherein the fine metal particles are zinc particles.

16. Steelmaking furnace (20) for manufacturing pig iron and separating fine metal particles, characterized in that it comprises: at least one upper tank (1); at least one lower tank (2); at least one fuel feeder positioned between the at least one upper tank (1) and the at least one lower tank (2); and at least one row of tuyeres (3, 4) positioned in at least one of the at least one upper tank (1) and the at least one lower tank (2), the at least one row of tuyeres (3, 4) fluidly communicating the interior of the furnace (20) with the external environment; and at least one burner positioned in at least one of the at least one upper tank (1) and the at least one lower tank (2); wherein the steelmaking furnace (20) is fed with a plurality of solid agglomerates comprising fine metal particles;and a system for separating fine metal particles from a steel furnace top gas (20) as defined in claim 1; connected to a gas outlet from the steel furnace (20) to separate the fine metal particles coming from the solid agglomerates and which are a by-product of the production of pig iron in the steel furnace (20).

17. Steel furnace (20), according to claim 16, characterized by the fact that the plurality of solid agglomerates comprising fine metallic particles consists of a plurality of solid agglomerates comprising electric steel mill dust, in which the plurality of solid agglomerates are a plurality of briquettes and in which the fine metallic particles are zinc particles.

18. The steel mill (20) of claim 16, wherein the plurality of solid agglomerates comprising fine metallic particles consists of a plurality of solid agglomerates comprising one or more of oxygen steel mill dust, willemite residues, steel mill co-products comprising zinc, or processed scrap comprising zinc.

19. Steel furnace (20) according to any one of claims 16 to 18, characterized in that the top temperature of the steel furnace (20) is between 600 °C and 700 °C.

20. Steel furnace according to any one of claims 16 to 19, characterized in that it is fed with a metallic charge comprising self-reducing briquettes, in which the metallic percentage is composed of any steel co-product that meets the minimum iron contents required for the production of pig iron.

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