Off-gas treatment structure of horizontal kiln

Abstract

According to the concept of the present invention, a horizontal kiln, which is for acquiring valuable metal through a calcination process for calcining a raw material, comprises: a chamber including a non-heating section, a preheating section, a high-temperature section, and a cooling section that are sequentially formed; a heater provided to heat the chamber; a transfer mechanism that transfers a sagger accommodating a raw material such that the sagger passes through the non-heating section, the preheating section, the high-temperature section, and the cooling section in sequence; and an exhaust port provided in the upper part of the chamber to discharge off-gas generated from the raw material in the sagger, wherein the sagger includes a sagger body that accommodates the raw material and has an upper surface that is opened, and a sagger cover that covers the opened upper surface of the sagger body, and the inside of the chamber is maintained at a positive pressure of 10 to 20 Kpa during the calcination process.

Description

Flue gas treatment structure of a horizontal kiln

[0001] The present invention relates to a horizontal kiln used in a high-temperature reduction process, and specifically, to a horizontal kiln having a structure capable of efficiently discharging exhaust gas generated from a material contained in a refractory case.

[0002] With the recent explosive increase in demand for electric vehicles (EVs), interest in recycling methods for spent EV batteries has also surged. EV batteries contain large quantities of valuable metals such as nickel, cobalt, manganese, and lithium, making their recycling value very high. While these metals are essential for the battery manufacturing process, their production can have harmful environmental impacts. In particular, environmental issues such as greenhouse gas emissions and ecosystem destruction arising from mining operations are serious. Therefore, the development of spent battery recycling technologies is essential for sustainable future development.

[0003] To recycle these waste batteries, black powder is first extracted through crushing, grinding, gravity separation, magnetic separation, etc. The black powder may contain oxides of the cathode materials nickel, cobalt, manganese, lithium, and aluminum, as well as graphite, the anode material, and impurities such as aluminum and copper.

[0004] Methods for recovering valuable metals from black powder can be broadly classified into two types: wet processes and high-temperature dry processes. The wet process is a method that produces NiSO4, CoSO4, MnSO4, and Li2CO3 through the steps of leaching, solvent extraction, and lithium production. The wet process has the disadvantage that the graphite contained in the black powder does not dissolve in strong acids, so the leaching process takes a long time, and the yield is low because carbon and metal are not perfectly separated.

[0005] The high-temperature dry process is a method that produces an alloy of nickel, cobalt, and manganese by reducing oxides of nickel, cobalt, manganese, lithium, and aluminum within black powder using carbon and oxygen blowing at high temperatures, and separates lithium and aluminum from the slag. The alloy of nickel, cobalt, and manganese undergoes the same leaching and solvent extraction processes, and the time required for the leaching process can be reduced to approximately 70% of that of the wet process.

[0006] However, during the high-temperature reduction of oxides of nickel, cobalt, manganese, lithium, and aluminum in the high-temperature dry process, exhaust gases such as carbon monoxide, hydrogen gas, methane gas, or carbon dioxide gas are generated.

[0007] Since these flue gases shorten the lifespan of internal cargo or heaters in kilns used in high-temperature reduction processes, it is necessary to treat them rapidly at the time of generation. Furthermore, if the flue gases diffuse throughout the entire kiln, the exhaust fans must be operated at high speed to expel them; however, this can cause heat within the kiln to escape along with the flue gases, thereby reducing the kiln's thermal efficiency. Therefore, it is essential to be able to rapidly treat the flue gases while preventing their diffusion.

[0008] The present invention discloses a horizontal kiln having a flue gas discharge structure that prevents flue gas generated from a material contained in a saggar / sagger from diffusing inside the furnace and efficiently discharges it within a short period of time.

[0009] The technical problems to be solved in this document are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this invention belongs from the description below.

[0010] According to one embodiment of the present invention, a horizontal furnace for obtaining a valuable metal through a firing process for firing a raw material comprises: a chamber including a sequentially formed non-heating section, a preheating section, a high-temperature section, and a cooling section; a heater provided to heat the chamber; a conveying mechanism for conveying a refractory box containing a raw material to pass through the non-heating section, the preheating section, the high-temperature section, and the cooling section in sequence; and an exhaust port provided at the top of the chamber to exhaust exhaust gas generated from the raw material of the refractory box; wherein the refractory box includes a refractory box body having an open top surface that contains the raw material and a refractory box cover that covers the open top surface of the refractory box body, and during the firing process, the interior of the chamber is maintained at a positive pressure of 10 to 20 kPa.

[0011] The cross-sectional area of ​​the above-mentioned non-heating section may be smaller than the cross-sectional area of ​​the above-mentioned preheating section.

[0012] The height of the above non-heating section may be smaller than the height of the above preheating section.

[0013] The above-mentioned refractory cover may include a cover penetration hole provided to allow exhaust gas generated from the raw material to be discharged toward the exhaust port.

[0014] The above cover penetration hole may coincide with or be adjacent to the line below the vertical direction of the exhaust port.

[0015] The above cover through-hole may have a shape of any one of a circle, a polygon, or an ellipse.

[0016] The above cover through-hole may include a plurality of micro-holes distributed among each other.

[0017] The above-mentioned refractory cover may include a protruding guide tube portion to guide exhaust gas exhausted through the cover penetration hole.

[0018] The above refractory boxes are arranged in at least two rows along the width direction of the chamber and transported along the length direction of the chamber, and the exhaust port may be arranged in at least two rows along the width direction of the chamber to correspond to the refractory boxes arranged in at least two rows.

[0019] The above refractory box includes a first row refractory box arranged in a first row and a second row refractory box arranged in a second row spaced apart from the first row along the width direction of the chamber, and the exhaust port may include a first row exhaust port located above the first row refractory box and a second row exhaust port located above the second row refractory box.

[0020] In the above preheating section, the temperature gradually rises to a predetermined temperature range, in the above high temperature section, the temperature is maintained at the above predetermined temperature range, and in the above cooling section, the temperature gradually decreases from the above predetermined temperature range, and the above predetermined temperature range may be in the range of 1000 degrees to 1300 degrees.

[0021] The above heater may be placed in sections other than the above non-heated section.

[0022] The above cooling section may include a slow cooling section, an air cooling section, and a water cooling section formed sequentially along the longitudinal direction of the chamber.

[0023] The above raw material may include crushed waste batteries.

[0024] According to one embodiment of the present invention, exhaust gas generated from a material contained in a refractory container is prevented from diffusing inside the furnace and is efficiently discharged within a short period of time, thereby increasing the efficiency of the reduction reaction and improving the overall equipment durability of the furnace.

[0025] According to one embodiment of the present invention, the indiscriminate diffusion of exhaust gas into the furnace is prevented by the refractory cover, and accelerated operation of the exhaust fan may be unnecessary. Accordingly, the positive pressure inside the furnace can be stably maintained.

[0026] According to one embodiment of the present invention, the non-heating section of the chamber is formed with a smaller cross-sectional area compared to the preheating section of the chamber, so that the air velocity decreases when entering the preheating section, allowing exhaust gas to be discharged intensively. Accordingly, pressure changes are minimized from the point where the preheating section ends, and the positive pressure inside the chamber can be stably maintained.

[0027] According to one embodiment of the present invention, an exhaust port provided at the top of the furnace body to exhaust exhaust gas generated from the refractory box can be positioned in a transfer line through which the refractory box is transported. If the refractory box is arranged in at least two rows along the width direction of the chamber, the exhaust port can also be arranged in at least two rows corresponding to this. Accordingly, the flow of exhaust gas can be concentrated upward, unnecessary diffusion can be suppressed, and pressure imbalance can be prevented.

[0028] As a result, according to one embodiment of the present invention, the positive pressure inside the furnace is stably maintained, thereby minimizing heat loss inside the furnace and maintaining a constant reducing atmosphere, which can increase the overall efficiency of the reduction reaction.

[0029] The effects according to the technical concept of the present invention are not limited to the effects mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0030] FIG. 1 is a schematic diagram illustrating a horizontal kiln according to one embodiment of the present invention.

[0031] FIG. 2 is a diagram illustrating the temperature profile of a horizontal kiln according to one embodiment of the present invention.

[0032] FIG. 3 is a drawing illustrating a cross-section of a non-heated section of a horizontal kiln according to an embodiment of the present invention, as an example of a cross-section along line I-I of FIG. 1.

[0033] FIG. 4 is a drawing illustrating a cross-section of a preheating section of a horizontal kiln according to an embodiment of the present invention, as an example of a cross-section along line II-II of FIG. 1.

[0034] FIG. 5 is a drawing illustrating a refractory box according to one embodiment of the present invention.

[0035] FIG. 6 is a drawing showing the refractory body and the refractory cover separated according to one embodiment of the present invention.

[0036] FIG. 7 is a drawing illustrating a refractory box according to another embodiment of the present invention.

[0037] FIG. 8 is a drawing illustrating a refractory box according to another embodiment of the present invention.

[0038] FIG. 9 is a drawing illustrating a refractory box according to another embodiment of the present invention.

[0039] The embodiments described in this specification and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and various modifications that may replace the embodiments and drawings of this specification may exist at the time of filing this application.

[0040] Additionally, the same reference numerals or symbols presented in each drawing of this specification represent parts or components that perform substantially the same function.

[0041] Furthermore, the terms used in this specification are for describing embodiments and are not intended to limit or / or restrict the disclosed invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0042] Additionally, terms including ordinal numbers, such as "first," "second," etc., used herein may be used to describe various components, but said components are not limited by said terms, and said terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any one of a plurality of related described items.

[0043] Furthermore, in this disclosure, the meaning of "identical" includes items that are similar in attributes or similar within a certain range. Additionally, "identical" means "substantially identical." The meaning of "substantially identical" should be understood as including within the scope of "identical" numerical values ​​that fall within the margin of error in manufacturing or values ​​that correspond to differences within a range that do not hold significance relative to a reference value.

[0044] Additionally, when it is said that a component is "connected," "combined," "supported," or "in contact" with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0045] Hereinafter, a horizontal kiln according to the present invention will be described in detail together with the attached drawings.

[0046] FIG. 1 is a schematic diagram illustrating a horizontal kiln according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a temperature profile of a horizontal kiln according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a cross-section of a non-heated section of a horizontal kiln according to an embodiment of the present invention, as an example of a cross-section along line I-I of FIG. 1. FIG. 4 is a diagram illustrating a cross-section of a preheated section of a horizontal kiln according to an embodiment of the present invention, as an example of a cross-section along line II-II of FIG. 1.

[0047] Referring to FIGS. 1 to 4, a horizontal kiln (1) according to one embodiment of the present invention can heat and fire raw materials contained in a refractory container (500).

[0048] The raw material may include crushed and ground waste batteries. The crushed and ground waste batteries may include oxides of nickel, cobalt, manganese, lithium, and aluminum as cathode materials, graphite as a negative electrode material, and impurities such as aluminum and copper.

[0049] A horizontal furnace (1) may include a furnace body (100) having a chamber (200), a transfer mechanism (300) provided to transfer a refractory box (500) to the chamber (200), and a heater (400) provided to heat the chamber (200).

[0050] The chamber (200) is a space formed inside the furnace body (100) so that raw materials are placed in a refractory container (500) and moved to be heat-treated. The chamber (200) may be a tunnel-shaped space surrounded by insulating walls. That is, the chamber (200) may be a space surrounded by a ceiling wall (110), a floor wall (120), a left wall (130), and a right wall (140).

[0051] The chamber (200) can allow a refractory container (500) containing raw material to be fired while moving continuously. The chamber (200) may have a length direction (X), a width direction (Y), and a height direction (Z). The length direction (X) of the chamber (200) may be a horizontal direction.

[0052] The refractory casing (500) can be moved inside the chamber (200) along the longitudinal direction (X) of the chamber (200). The refractory casing (500) can be arranged in at least two rows along the width direction (Y) of the chamber (200) and transported along the longitudinal direction (X) of the chamber (200). The refractory casings (500) of each row can be stacked in multiple layers along the height direction (Y) of the chamber (200).

[0053] A horizontal kiln (1) according to one embodiment of the present invention may include an inlet shutter (210) provided to open and close the inlet of a chamber (200) and an outlet shutter (220) provided to open and close the outlet of a chamber (200).

[0054] A horizontal kiln (1) according to one embodiment of the present invention may include a supply replacement chamber (10) provided outside the inlet side of the chamber (200) to supply a refractory plate (500) to the chamber (200), and a discharge replacement chamber (20) provided outside the outlet side of the chamber (200) to discharge the refractory plate (500) from the chamber (200).

[0055] The supply replacement chamber (10) can be connected to the chamber (200) when the inlet shutter (210) is opened. The discharge replacement chamber (20) can be connected to the chamber (200) when the outlet shutter (220) is opened.

[0056] The supply replacement chamber (10) and the discharge replacement chamber (20) can prevent external air from entering the chamber (200) and changing the atmosphere when the inlet shutter (210) and the outlet shutter (220) are opened.

[0057] Meanwhile, if air is introduced into the chamber (200) from the outside, there may be a risk of an explosion reaction during the reduction process. Therefore, it is desirable to maintain the pressure inside the chamber (200) at a positive pressure. In addition, by maintaining the inside of the furnace at a positive pressure, heat loss inside the furnace is minimized and the reduction atmosphere is maintained at a constant level, which can increase the overall efficiency of the reduction reaction.

[0058] According to one embodiment of the present invention, it may be preferable for the pressure inside the chamber (200) to be maintained in the range of 10 to 20 kPa during the litigation process.

[0059] The transfer mechanism (300) can transfer a refractory case (500) containing raw material within the chamber (200).

[0060] The transfer mechanism (300) may include a support plate (310) that supports the refractory box (500), a rail (320) that extends in the longitudinal direction (X) of the chamber (200) to guide the movement of the support plate (310), and a pusher (not shown) that pushes and moves the refractory box (500). The pusher may stop for a certain period of time after pushing the refractory box (500) and then repeat the action of pushing the refractory box (500) again, thereby allowing the refractory box (500) to be heated according to the temperature profile inside the chamber (200).

[0061] However, the structure of the transfer mechanism (300) is not limited to this pusher method and may be composed of a conveyor belt structure or a roller structure.

[0062] The chamber (200) may include a plurality of sections partitioned according to the temperature profile shown in FIG. 2. Specifically, the chamber (200) may include a non-heating section (A), a preheating section (B), a high-temperature section (C), and cooling sections (D, E, F) arranged sequentially along the longitudinal direction (X) of the chamber (200).

[0063] The preheating section (B) is a section where the temperature gradually rises to a predetermined temperature range. In the preheating section (B), the shredded waste battery is preheated, and the electrolyte and separator can be removed.

[0064] The high temperature section (C) is a section where the temperature is maintained within a predetermined temperature range. The high temperature section (C) is the section with the highest temperature within the chamber (200), and heat treatment of raw materials can be performed in the range of 1000 degrees to 1300 degrees. In the high temperature section (C), nickel, cobalt, and manganese alloys containing valuable metals and Li oxides can be produced.

[0065] The cooling section (D, E, F) is a section where the temperature gradually decreases within a predetermined temperature range. The cooling section (D, E, F) can stabilize the reduction reaction product generated through the high temperature section (C) by cooling it. The cooling section (D, E, F) can be divided into a slow cooling section (D), an air cooling section (E), and a water cooling section (F).

[0066] The slow cooling section (D) is a section where the temperature gradually decreases to prevent cracking and deformation of the reactants. The air cooling section (E) is a section where the reactants are cooled by flowing air through a fan or blower. The water cooling section (F) is a section where the reactants are rapidly cooled using cooling water.

[0067] The non-heating section (A) is provided between the entrance of the chamber (200) and the preheating section (B) and is a section where heating does not occur. That is, a heater (400) may not be placed in the non-heating section (A).

[0068] The cross-sectional area of ​​this non-heating section (A) can be made smaller than the cross-sectional area of ​​the preheating section (B).

[0069] Specifically, as illustrated in FIGS. 3 and 4, the height (h1) of the non-heating section (A) may be smaller than the height (h2) of the preheating section (B). The height (h1) of the non-heating section (A) may be the distance between the floor wall (120) and the ceiling wall (110) of the non-heating section (A). The height (h2) of the preheating section (B) may be the distance between the floor wall (120) and the ceiling wall (110) of the preheating section (B). The width of the non-heating section (A) and the width of the preheating section (B) may be the same.

[0070] In this way, by making the cross-sectional area of ​​the non-heating section (A) smaller than the cross-sectional area of ​​the preheating section (B), the structure of the supply replacement chamber (10), the non-heating section (A), and the preheating section (B) can be a Venturi structure. Accordingly, when the inlet shutter (210) is opened, the air flowing into the interior of the chamber (200) flows rapidly in the non-heating section (A) and then the flow velocity can be reduced in the preheating section (B).

[0071] As a result, the speed of the air and exhaust gas flow in the preheating section (B) is slowed down, and the exhaust gas is stagnated at the top of the preheating section (B), thereby enabling the exhaust gas to be discharged quickly and effectively through the exhaust port (900).

[0072] In addition, as the exhaust gas is rapidly and intensively discharged in the preheating section (B) in this manner, pressure changes in the sections after the preheating section (B) can be minimized and positive pressure can be effectively maintained. Accordingly, external air is prevented from entering the furnace in the high-temperature section (C), thereby maintaining a stable reducing atmosphere and minimizing heat loss. As a result, the overall efficiency of the high-temperature reduction reaction can be increased.

[0073] A heater (400) may be provided to heat the interior of the chamber (200). The heater (400) may include a resistive electric heater that includes a resistor and utilizes the resistive heat generated when current flows. Alternatively, the heater (400) may include a gas burner type heater that utilizes the combustion heat of natural gas or LPG.

[0074] According to one embodiment of the present invention, the heater (400) may be in a form that extends in a vertical direction (Z direction) from the chamber (200). The heater (400) may be positioned on both sides of a plurality of refractory boxes (500) and between a plurality of refractory boxes (500). The heater (400) may be positioned spaced apart from each other along the longitudinal direction of the chamber (200). The heater (400) may be positioned spaced apart at regular intervals along the longitudinal direction of the chamber (200).

[0075] The heater (400) may be placed in the front of the preheating section (B), the high temperature section (C), and the cooling sections (D, E, F), and may not be placed in the non-heating section (A). Each heater (400) may be controlled independently to adjust the temperature of each section according to the temperature profile of the chamber (200).

[0076] A horizontal kiln (1) according to one embodiment of the present invention may include an inlet (not shown) for supplying a supply gas containing an inert gas such as argon and nitrogen and oxygen into the interior of a chamber (200).

[0077] A horizontal kiln (1) according to one embodiment of the present invention may include an exhaust port (900) to exhaust exhaust gas generated inside a chamber (200).

[0078] The flue gas may contain carbon monoxide, hydrogen gas, methane gas, or carbon dioxide gas generated during the high-temperature reduction of oxides of nickel, cobalt, manganese, lithium, and aluminum.

[0079] The exhaust port (900) may be provided on the upper part of the main body (100).

[0080] According to one embodiment of the present invention, the refractory box (500) may be arranged in at least two rows along the width direction (Y) of the chamber (200) and transported along the length direction (X) of the chamber (200), and the exhaust port (900) may be arranged in at least two rows along the width direction (Y) of the chamber (200) to correspond to the arrangement of the refractory box (500).

[0081] That is, as illustrated in FIG. 4, the refractory box (500) includes a first row refractory box (510) arranged in a first row and a second row refractory box (520) arranged in a second row spaced apart from the first row along the width direction (Y) of the chamber (200), and the exhaust port (900) may include a first row exhaust port (910) located above the first row refractory box (510) and a second row exhaust port (920) located above the second row refractory box (520).

[0082] Specifically, the first heat exhaust port (910) may be located above the transfer line through which the first heat refractory plate (510) is transferred in the longitudinal direction (X) of the chamber (200), and the second heat exhaust port (920) may be located above the transfer line through which the second heat refractory plate (520) is transferred in the longitudinal direction (X) of the chamber (200).

[0083] However, the refractory box (500) and the exhaust port (900) are not required to be arranged in only two rows, and the refractory box (500) and the exhaust port (900) may be arranged in one row or in more rows.

[0084] In this way, the exhaust port (900) is positioned to correspond to the rows of refractory casings (500) along the width direction (Y) of the chamber (200), thereby shortening the exhaust path of the exhaust gas and allowing the exhaust gas generated from each row of refractory casings (500) to flow upward toward the corresponding exhaust port (900) located directly above, so that it can be discharged quickly and efficiently. Accordingly, the flow of exhaust gas can naturally flow upward, and unnecessary retention or diffusion is suppressed, which helps maintain positive pressure inside the furnace.

[0085] In addition, since the exhaust gas generated from the refractory casing (500) of each row is dispersed and discharged through the exhaust port (900) placed in each row, a large amount of exhaust gas can be discharged at once while maintaining positive pressure inside the furnace, and the load on each exhaust port (900) can be reduced.

[0086] FIG. 5 is a drawing illustrating a refractory box according to one embodiment of the present invention. FIG. 6 is a drawing illustrating a refractory box body and a refractory box cover separated according to one embodiment of the present invention. FIG. 7 is a drawing illustrating a refractory box according to another embodiment of the present invention. FIG. 8 is a drawing illustrating a refractory box according to another embodiment of the present invention. FIG. 9 is a drawing illustrating a refractory box according to another embodiment of the present invention.

[0087] A refractory box (500) according to one embodiment of the present invention may include a refractory box body (600) and a refractory box cover (700). The refractory box body (600) and the refractory box cover (700) may be formed of a material such as silicon carbide that can withstand high temperatures.

[0088] The refractory body (600) may include a receiving space (660) capable of receiving raw materials, a bottom surface (610) and side surfaces (620, 630, 640, 650) forming the receiving space (660). The top surface of the refractory body (600) may be open to allow the raw materials to flow in and out.

[0089] An exhaust gas outlet (670) may be formed on the side (620, 630, 640, 650) of the refractory body (600) to discharge exhaust gas generated as the raw material contained in the refractory body (600) is fired. The exhaust gas outlet (670) may be formed in a notch shape on the upper side (620, 630, 640, 650) of the refractory body (600).

[0090] The refractory cover (700) may be provided to cover the open upper surface of the refractory body (600). By the refractory cover (700) covering the open upper surface of the refractory body (600), exhaust gas generated from the raw material may be prevented from being indiscriminately discharged all at once and spreading throughout the entire furnace.

[0091] That is, if the upper surface of the refractory body (600) is not covered by the refractory cover (700), the exhaust gas can spread throughout the entire furnace as it diffuses. At this time, if an exhaust device such as an exhaust fan is operated strongly to discharge the diffused exhaust gas, a problem may occur in which not only the exhaust gas but also the heat inside the furnace escapes together.

[0092] According to one embodiment of the present invention, this problem can be resolved by a refractory cover (700) that covers the open upper surface of a refractory body (600).

[0093] According to one embodiment of the present invention, when the refractory cover (700) covers the open upper surface of the refractory body (600), the exhaust gas generated from the raw material can be discharged through the exhaust gas discharge port (670) formed on the side of the refractory body (600).

[0094] The location and size of the exhaust gas discharge port (670) can be appropriately designed considering the amount of exhaust gas generated and the discharge speed. Additionally, the exhaust gas discharge port (670) may not be formed on all four sides of the refractory body (600), but may be formed on only some of the sides.

[0095] The refractory cover (700) may include a cover through-hole (710) formed to allow exhaust gas to be discharged.

[0096] The cover through hole (710) may be positioned to coincide with or adjacent to the vertical lower line of the exhaust port (900). In this case, the flow distance between the cover through hole (710) and the upper exhaust port (900) becomes the shortest distance, so that the exhaust gas discharged through the cover through hole (710) does not flow in a different direction but flows upward and can be quickly discharged through the exhaust port (900).

[0097] However, it is most efficient for the cover penetration hole (710) to align with the vertical lower line of the exhaust port (900), but it is not limited to this as there is no problem with discharge even if it does not align.

[0098] The cover penetration hole (710) may be positioned in the center of the refractory cover (700). However, the location of the cover penetration hole (710) is not limited to this and may be formed in the periphery rather than the center of the refractory cover (700).

[0099] The shape of the cover through-hole (710) can be circular. However, the shape of the cover through-hole (710) is not limited to this, and can be formed in various polygonal shapes such as triangles, squares, pentagons, or elliptical shapes.

[0100] Additionally, as shown in FIG. 7, the cover through hole (710) may not be formed as a single hole, but may be composed of a plurality of micro-holes (720) distributed among each other.

[0101] As illustrated in FIG. 8, the refractory cover (700) may include a guide tube (730) for guiding exhaust gas exhausted through the cover penetration hole (710).

[0102] The guide tube (730) may protrude from the upper surface of the refractory box cover (700). The guide tube (730) can guide the exhaust gas generated inside the refractory box (500) toward the exhaust port (900) to more effectively prevent the exhaust gas from spreading.

[0103] As shown in FIG. 9, the cover through hole (710) in the refractory cover (700) is not necessarily required, and depending on the embodiment, the cover through hole (710) may be omitted.

[0104] Specific embodiments have been illustrated and described above. However, the invention is not limited to the embodiments described above, and those skilled in the art may make various modifications without departing from the essence of the technical concept of the invention as described in the following claims.

Claims

1. In a horizontal kiln for obtaining valuable metals through a calcination process for calcining raw materials, A chamber comprising a sequentially formed non-heating section, a preheating section, a high-temperature section, and a cooling section; A heater provided to heat the above chamber; A conveying mechanism for conveying a refractory container containing raw materials to pass through the non-heating section, preheating section, high temperature section, and cooling section in sequence; and It includes an exhaust port provided at the top of the chamber to exhaust exhaust gas generated from the raw material of the refractory case; and The above refractory box includes a refractory box body having an open upper surface that accommodates raw materials, and a refractory box cover that covers the open upper surface of the refractory box body. A horizontal kiln in which the interior of the chamber is maintained at a positive pressure of 10 to 20 kPa during the above firing process.

2. In Paragraph 1, A horizontal kiln in which the cross-sectional area of ​​the above-mentioned non-heating section is smaller than the cross-sectional area of ​​the above-mentioned preheating section.

3. In Paragraph 2, A horizontal kiln in which the height of the above-mentioned non-heating section is smaller than the height of the above-mentioned preheating section.

4. In Paragraph 1, The above-described refractory cover is a horizontal kiln comprising a cover penetration hole provided to allow exhaust gas generated from the raw material to be discharged toward the exhaust port.

5. In Paragraph 4, The above cover penetration hole is aligned with or adjacent to the horizontal kiln in the vertical direction below the exhaust port.

6. In Paragraph 4, The above cover through-hole is a horizontal kiln having a shape among a circle, a polygon, or an ellipse.

7. In Paragraph 4, The above cover through-hole is a horizontal firing furnace comprising a plurality of micro-holes distributed among each other.

8. In Paragraph 4, The above refractory cover is a horizontal kiln that includes a guide tube portion protruding to guide exhaust gas exhausted through the cover penetration hole.

9. In Paragraph 1, The above refractory casings are arranged in at least two rows along the width direction of the chamber and transported along the length direction of the chamber, The above exhaust port is a horizontal kiln arranged in at least two rows along the width direction of the chamber to correspond to the above at least two rows of refractory boxes.

10. In Paragraph 9, The above refractory box includes a first row refractory box disposed in a first row and a second row refractory box disposed in a second row spaced apart from the first row along the width direction of the chamber. The above exhaust port is a horizontal furnace comprising a first heat exhaust port located above the first heat refractory box and a second heat exhaust port located above the second heat refractory box.

11. In Paragraph 1, In the above preheating section, the temperature gradually rises to a predetermined temperature range, and In the above high-temperature section, the temperature is maintained within the above predetermined temperature range, and In the above cooling section, the temperature gradually decreases within the above predetermined temperature range, and A horizontal kiln in which the above-mentioned predetermined temperature range is 1,000 degrees to 1,300 degrees.

12. In Paragraph 1, The heater is a horizontal kiln placed in sections other than the non-heating section.

13. In Paragraph 1, The above cooling section is a horizontal kiln comprising a slow cooling section, an air cooling section, and a water cooling section formed sequentially along the longitudinal direction of the chamber.

14. In Paragraph 1, The above raw material is a horizontal kiln containing crushed waste batteries.

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