KR102645717B1 - A Furnace for Burning a Secondary Dross of Aluminum and a Method for Treating the Same - Google Patents

Abstract

The present invention relates to a calciner for processing aluminum secondary dross and a processing method thereof. The calcining furnace for aluminum secondary dross processing includes a furnace body 41 with a combustion space formed inside; A burner 42 that initiates combustion inside the furnace body 41; A door 43 formed on the furnace body 41; and a supply means for supplying aluminum secondary dross dust into the interior of the furnace body 41, wherein the inner wall of the furnace body 41 is made of a refractory material that can withstand a temperature of at least 1800°C.

Description

Calcination furnace for secondary dross processing of aluminum and its processing method {A Furnace for Burning a Secondary Dross of Aluminum and a Method for Treating the Same}

The present invention relates to a calciner for processing aluminum secondary dross and a processing method thereof. Specifically, in the process of treating primary dross generated in the aluminum melting process, residual aluminum metal is first recovered and the remaining fine residual dust is secondary. To provide a calcining furnace for processing and a processing method thereof.

One of the biggest challenges for the industry producing aluminum products is properly handling secondary dross. There is a need to increase competitiveness by increasing the use of low-cost scrap to recycle resources and lower production costs.

To this end, it is necessary to first reprocess the dross corresponding to a large amount of aluminum oxide, which is generated at a level of 15 to 20% in the process of dissolving scrap, and properly dispose of the remaining residue/dust.

In addition, such dust may be generated at the bottom of the dust collection device, and since there are no laws and regulations for treating the dust remaining after the primary reprocessing of dross or the dust from the dust collection device, there is a problem in that there is no way to properly dispose of it.

For all alloy companies and billet producers that use large quantities of compressed chassis scrap, it is difficult to process the secondary dross remaining after recovering the primary residual metal from the oxidized dross generated during the production process. , there is no way to handle it according to the scope of current laws and regulations.

As a result, each company stores hundreds or thousands of tons of dross, and this accumulated dross combines with moisture and spontaneously ignites, causing fire and environmental problems such as air pollution, odor generation, and dust generation.

In the case of residual dross, recycling is possible if the aluminum metal content exceeds a certain percentage, but as the supply is greater than demand, a significant amount of dross is classified as waste and is not recycled but remains in inventory.

If the content of aluminum metal in the residual dross falls below a certain percentage, the residual dross becomes a complete waste and can be reprocessed and then landfilled. If it is not recycled, there is no way to dispose of it.

Regarding the processing of dross, Patent Publication No. 10-2019-0084437 discloses a method of processing aluminum dross. Additionally, Patent Registration No. 10-1393109 discloses a method and system for recycling aluminum dross.

However, prior art or known technology does not disclose technology for processing secondary dross generated after reprocessing primary dross.

The present invention is intended to solve the problems of the prior art and has the following purposes.

Prior Art 1: Patent Publication No. 10-2019-0084437 (Myeong-ae Kim, published on July 17, 2019) Processing method of aluminum dross Prior art 2: Patent registration number 10-1393109 (Korea Institute of Industrial Technology, announced on May 13, 2014) Recycling method and system for aluminum dross

The object of the present invention is to provide a calcining furnace and a processing method for treating secondary dross generated by reprocessing aluminum dross.

According to a preferred embodiment of the present invention, a calcining furnace for aluminum secondary dross processing includes a furnace body having a combustion space formed therein; A burner that initiates combustion inside the furnace body; A door formed on the furnace body 41; and a supply means for supplying aluminum secondary dross dust into the interior of the furnace body, wherein the inner wall of the furnace body is made of a refractory material that can withstand a temperature of at least 1800°C.

According to another suitable embodiment of the present invention, the door has a swing structure or an up-down structure, and the supply means includes an input chute flowing into the interior of the furnace body.

According to another suitable embodiment of the present invention, the supply means includes a hopper connected to a transfer screw for transferring aluminum secondary dross dust; an elevator extending vertically from the hopper; A storage tank for storing secondary dross dust transported along the elevator; and a supply induction unit that injects secondary dross dust stored in the storage tank into the interior of the furnace body.

According to another suitable embodiment of the present invention, a method for processing aluminum secondary dross includes the steps of cooling and pulverizing the remnants of the reprocessed dross while transporting them; Separating dross dust from pulverized secondary dross; Injecting dross dust into the interior of a calcining furnace in which combustion initiation means is installed; Inducing a spontaneous combustion reaction of dross dust inside the calciner; and generating a reactant by combustion of dross dust.

According to another suitable embodiment of the present invention, calcium oxide or solid fluorine is added for pollution-free treatment of the reaction product of dross dust.

The calciner for aluminum secondary dross processing according to the present invention processes secondary dross generated after reprocessing primary dross generated during the production of aluminum products so that it can be used as building materials, refractories, or water purification agents.

Accordingly, the remaining dross after aluminum treatment is processed in a calciner so that the dross can be completely processed without leaving any additional waste.

The method for treating secondary dross according to the present invention makes it possible to obtain raw materials that can be used as building materials, refractories, or water purification agents by, for example, burning them together with dust collected from a dust collection device.

The calcining furnace or processing method according to the present invention allows combustion to be initiated by a combustion initiating means such as a burner, and combustion is maintained through thermite reaction without the use of separate combustion raw materials, thereby avoiding separate combustion costs.

In addition, the calcining furnace or processing method according to the present invention allows secondary dross to be processed without deviating from current laws and regulations, and environmental problems caused by storage of secondary dross are solved.

The calcining furnace according to the present invention may have various structures. For example, the calcining furnace may be made of a rotary furnace structure.

The treatment method according to the present invention makes it possible, for example, to treat together the dust collection powder and residual dross collected at the bottom of the dust collection device.

Additionally, dross dust has the advantage of being able to be directly transported to the calciner through a transport means connected to the primary dross processing device. Accordingly, it has the advantage that E-ra melting/primary dross treatment/metal recovery/calcination treatment of residual dross can be processed by one system in the same space.

Figures 1 and 2 show an embodiment of a dross reprocessing device that is combined with a calcining furnace according to the present invention and allows secondary dross to be introduced into the calcining furnace.
Figure 3 shows an example of a structure in which coolant is introduced in the reprocessing device of Figure 1 or 2.
Figures 4, 5 and 6 show an example of a calcining furnace for aluminum secondary dross processing according to the present invention.
Figure 7 shows an embodiment of a method for processing aluminum secondary dross according to the present invention.

Below, the present invention will be described in detail with reference to the embodiments shown in the attached drawings, but the examples are for a clear understanding of the present invention and the present invention is not limited thereto.

In the description below, components having the same reference numerals in different drawings have similar functions, so unless necessary for understanding the invention, the description will not be repeated, and well-known components will be briefly described or omitted, but the present invention It should not be understood as being excluded from the embodiments.

Figures 1 and 2 show an embodiment of a dross reprocessing device that is combined with a calcining furnace according to the present invention and allows secondary dross to be introduced into the calcining furnace.

Referring to Figures 1 and 2, the calcining furnace for aluminum secondary dross processing includes a furnace body 41 with a combustion space formed therein; A burner 42 that initiates combustion inside the furnace body 41; A door 43 formed on the furnace body 41; and a supply means for supplying aluminum secondary dross dust into the interior of the furnace body 41, wherein the inner wall of the furnace body 41 is made of a refractory material that can withstand a temperature of at least 1,800°C.

For the processing of aluminum secondary dross, aluminum secondary dross can be made, and aluminum secondary dross can be produced from aluminum primary dross.

An aluminum recovery module 10 may be installed to reprocess aluminum dross, and residues after reprocessing may be transferred to the cooling grinding module 20 by the aluminum recovery module 10.

After the residue is cooled and pulverized in the cooling and grinding module 20, the residue may be sorted according to size. Specifically, the grinding residue can be sorted into dross dust in the form of dust or powder, dross particles in the form of granules, and dross lumps with a relatively large volume.

The dross granules can be input into the cold material of the aluminum recovery module 10 through the return module 30, and the dross lumps can be recycled into aluminum materials. And the dross dust can be automatically transferred to the calciner 40 and burned to make raw materials such as building materials, refractory materials, or water purification agents.

Below, this process is explained in detail.

The aluminum recovery module 10 includes a drive module 11 in which dross is reprocessed; A heating material input module 12 that is input during the process of reprocessing aluminum dross; A crucible (13) in which the introduced aluminum dross is melted; It includes an impeller (14) rotated inside the crucible (13) by an integrated drive shaft (15) connected to a drive module (11) including a motor, and a collection unit (16) in which aluminum recovered from the input dross is collected. can do.

The dross treated in the melting furnace is collected in the dross recovery port (POT) or crucible 13, and then mounted on the dross processing device 10 by a forklift, and then the dross is melted by the operation of the stirring impeller 14. The impeller 14 can be rotated and moved up and down during the melting process. If overheating occurs during the melting process, coolant is added through the coolant input unit 34 to adjust the temperature.

A vortex may be generated by the rotation of the impeller 14, and aluminum, which has a relatively large specific gravity in the molten aluminum dross, may be separated downward and collected in the collection unit 16.

In this way, the aluminum is separated from the primary aluminum dross, and the remaining secondary dross can be transferred to the cooling grinding module 20 by the input hopper unit 18 of the inversion device 21.

The secondary dross can be inverted with the inversion device 21 and fed into the kiln 22. Inside the kiln 22, the secondary dross can be pulverized as it cools during the movement process, and the pulverized secondary dross can be sorted in the sorting module 23.

The sorting module 23 may have a screen structure with a mesh of a predetermined size on the circumferential surface of a cylindrical rotating body.

The sorting module 23 includes a dust separation unit 24 that separates dust or powder from the pulverized secondary dross; A granule separation unit 25 that separates granules; and a lump collection unit (28).

The dust separation unit 24 can separate dust or powder with a diameter of, for example, 0.5 mm or less, and the grain separation unit 25 can separate grains with a diameter ranging from 0.5 mm to 3 mm. .

The dust separated by the dust separation unit 24 contains a trace amount of aluminum, and the grains separated by the grain separation unit 25 contain aluminum at a level that can be used as a cold material.

Then, the lumps separated by the lump separation unit are collected and discharged into the lump collection unit 28. The lumps collected in the lump collection unit 28 are transported by the lump transport unit 26, stored in the storage tank 27, and then re-melted in an aluminum melting furnace and recycled.

The grains separated by the grain separation unit (25) are stored in the grain discharge device (31). It can be transferred to the aluminum recovery module 10 through the return module 30 and used as cold material. Specifically, the separated grains may be moved by the screw conveyor 31 and moved along the conveyor belt conveyor 32.

The grains transported by the conveyor belt conveyor 32 may be input into the grain input hopper 33 and then vertically transported by a vertical transport device unit 17 such as a bucket elevator and then stored in the storage tank 35, Thereafter, the coolant can be input into the crucible of the aluminum recovery module 10 through the cold material input module 34.

The dross dust or powder may be transferred to the calciner 40. Specifically, dross dust can be input into the hopper 47 that collects dust by the dust transfer device screw conveyor 48, and the dross dust input into the hopper 47 is vertically transferred to the bucket elevator 49 and stored. It can be transported and stored in the tank 46.

Thereafter, the dross dust may be introduced into the interior of the furnace body 41 through the supply induction unit 45.

The inner peripheral wall of the furnace body 41 may be made of a refractory material, for example, a material that can withstand temperatures above 1,800°C. Additionally, the furnace body 41 may have a rotary furnace structure.

The dross dust can be naturally combusted by combustion initiation inside the furnace body 41. Optionally, dust generated from the lower part of the dust collection device may be added to the furnace body 41 together. There are no treatment regulations for the dust collected at the bottom of the dust collection device, so it is difficult to treat, and it can be treated together with secondary dross dust in the calciner.

When ignition of the secondary dross dust introduced into the interior of the furnace body 41 begins, the secondary dross dust itself becomes fuel and can naturally combust without the need for additional raw materials. A burner 42 may be installed to initiate ignition for such natural combustion, and the burner 42 may have an ignition initiation function.

A door 43 may be installed on the furnace body 41, and the door 43 may be a swing door or an up-down door, but is not limited thereto.

A supply means for introducing secondary dross dust may be installed into the furnace body 41. Specifically, the dross dust separated by the dust separation unit 24 may be transferred to the input hopper 47 after the dust is discharged by the dust discharge device 48.

The dross dust introduced into the hopper 47 may be stored in the storage tank 46.

The dross dust stored in the storage tank 46 may be introduced into the furnace body 41 via the supply induction unit 45.

The input chute 44 may be connected to the supply guide unit 45, and one end of the input chute 44 may be connected to the end of the supply guide unit 45 through a rotary joint structure.

When the door 43 is opened, the input chute 44 rotates based on the rotary joint so that the end of the input chute 44 can be located inside the furnace body 41, and dross dust is discharged from the storage tank 46. It can be transferred and put into the furnace body 41 through the putting chute 44.

When the input of the predetermined amount of dross dust is completed, the input chute 44 can be rotated and positioned outside the door 43, and in this state, the door 43 can be closed.

The door 43 may have various structures capable of sealing the furnace body 41, such as a double door, and the present invention is not limited thereto.

Figure 3 shows an example of a structure in which coolant is introduced in the reprocessing device of Figure 1 or 2.

Referring to FIG. 3, the dross particles separated from the secondary dross may be discharged from the particle discharge device 31 and transferred to the input hopper 33 by the transfer belt conveyor 32.

When the input of cold material is required in the aluminum recovery module, the dross grains input into the input hopper 33 are transferred to the input hopper 33, which has the function of a bucket that moves along a vertical transport device unit 17 such as a bucket elevator. The granules can be pumped, fed and stored in storage tanks.

Additionally, the dross particles are delivered to the cold material input unit for the injection of the cold material, so that the cold material can be automatically added to the crucible where the primary dross is processed whenever cold material dross grains are needed.

Injection of dross granules can be accomplished in a variety of ways and is not limited to the presented embodiment.

Figures 4, 5, and 6 show an embodiment of the calcining furnace 40 for aluminum secondary dross processing according to the present invention.

Referring to Figures 4, 5 and 6, the supply means includes a hopper 47 connected to a transfer screw for transferring aluminum secondary dross dust; an elevator 49 extending vertically from the hopper 47; a storage tank 46 for storing secondary dross dust transported along the elevator 49; and a supply induction unit 45 that introduces secondary dross dust stored in the storage tank 46 into the interior of the furnace body 41.

A circular door 43 may be installed in front of the furnace body 41, and the door 43 may have a swing structure or an up-down structure.

The peripheral wall of the furnace body 41, the inner part of the door 43, or the ceiling surface of the furnace body 41 may be made of a refractory material.

The burner 42 is installed in the furnace body 41 to perform an ignition initiation function, and dross dust can be transferred to the dust input hopper 47 by the dust transfer feeder 48.

The dross dust introduced into the dust input hopper 47 can be moved upward by the bucket elevator 49.

Specifically, the dross dust can be transferred to the dust storage tank 46 by transporting the dust using a bucket elevator 49 coupled with a dust transport basket.

If it is necessary to inject dross dust into the interior of the furnace body 41 to operate the calcining furnace 40, the door 43 may be opened.

When the door 43 is opened, the input chute 44 located outside the furnace body 43 is rotated so that the end of the input chute 44 is located inside the furnace body 41.

The input chute 44 may have an overall L shape, and one end of the input chute 44 may be connected to the supply guidance unit 45 through a rotary joint structure.

Specifically, a rotation tab 51 having an overall fallopian tube shape is formed at one end of the input chute 44, and a rotation induction ball 52 may be coupled to one end of the supply induction unit 45.

A portion of the rotation inducing ball 52 may be accommodated inside the rotation tab 51, and the input chute 44 may be rotated with respect to the supply inducing unit 45 by rotation of the rotation tab 51.

When the input chute 44 is rotated and its end is located inside the furnace body 41, the dross dust stored in the dust storage tank 46 moves along the supply guidance unit 45, and then the input chute 44 is moved. It can be moved along and put into the interior of the furnace body 41.

When a predetermined amount of dross dust is filled in the furnace body 41, the input chute 44 can be rotated to be positioned outside the furnace body 41, and the door 43 can be closed.

When the door 43 is closed and the combustion reaction is ready to start, the burner 42 is activated to initiate ignition, and then the dross dust or dust collected below in the dust collection device is ignited according to the start of ignition and separate Natural combustion can occur without the need for input of raw materials.

This process is explained in detail below.

Figure 7 shows an example of a method for processing aluminum secondary dross according to the present invention.

Referring to FIG. 7, the method of processing aluminum secondary dross includes the steps of cooling and pulverizing the reprocessed dross while transporting it (P71); Separating dross dust from pulverized secondary dross (P72); Injecting dross dust into the interior of a calciner equipped with combustion initiation means (P73); Inducing a spontaneous combustion reaction of dross dust inside the calciner (P74); and a step (P75) in which a reactant is generated by combustion of dross dust.

Additionally, calcium oxide or solid fluorine may be added for pollution-free treatment of the reaction product of dross dust.

Iron is removed from aluminum secondary dross, which is the residue of reprocessed aluminum dross, and dross dust can be separated from pulverized aluminum secondary dross through a cooling and grinding process (P72).

Dross dust has an aluminum content close to zero, and can become combustible when activated.

Dross dust in this state can be introduced into the calciner along with the dust collection powder or dust collector collected at the bottom of the dust collection device (P73).

For example, the weight ratio of dross dust: dust collector = 100: 100 to 10 may be introduced into the interior of the calciner, and the dross dust may be introduced into the interior of the calciner through an automatic transportation means as described above. It can be.

When dross dust is introduced into the calciner (P73), combustion can be started using a combustion start means such as a burner.

When dross dust naturally combusts inside the calciner, aluminum nitride is generated and a large amount of heat is released, and this heat can cause natural combustion of dross dust and dust collectors.

Aluminum nitride is a product made when aluminum powder is heated and reacted with nitrogen gas to a temperature of 820 to 1,000 ° C. It can become a gray amorphous solid.

Such aluminum nitride can be partially decomposed at a temperature of about 1,900°C and sublimated into a solid, forming a colorless hexagonal crystal.

In such a high temperature state, the aluminum nitride contained in the dross dust is burned to remove nitrogen, and along with this, the reactivity of secondary aluminum such as thermite reaction and combustibility such as spontaneous combustion and explosiveness can be removed.

Optionally, depending on the composition of the dross dust, calcium oxide or solid fluorine may be added for pollution-free treatment.

Calcium oxide is expressed as CaO and is called quicklime, white ash, or steel ash. It is a white, corrosive crystalline solid produced by thermal decomposition at a temperature of 900°C.

Quicklime reacts rapidly with water, releasing a large amount of heat and becoming calcium hydroxide or slaked lime.

The above process can be expressed in the reaction equation below.

CaCO ₃ -> CaO + CO ₂

CaO +H ₂ O -> Ca(OH) ₂

Solid fluorine is a light yellow gas with a unique odor that belongs to the halogen group and has the characteristic of combining with all gases except nitrogen.

If the calciner is filled with dross dust and dust collectors, the calciner can be made to a high temperature state, and when ignition is initiated by the burner, aluminum nitride is generated and a large amount of heat is released, which causes the temperature inside the sewer furnace to rise. For example, as the temperature rises to 1,900°C or higher, a spontaneous combustion reaction of dross dust can be induced.

And aluminum nitride may be sublimated by high heat to produce aluminum oxide (Al ₂ O ₃ ).

This reaction continues until the dross dust and dust collector are completely burned, and thus a reaction product whose main component is aluminum oxide (Al ₂ O ₃ ) can be created from the input dross dust and dust collector (P75).

Such reaction products can be used as industrial raw materials, for example, as building materials, refractories, or water purification materials (P76). Optionally, the reaction product may comprise a dusting powder that is collected downward in a dust collection device.

Various types of reactions may occur within the calciner, and the present invention is not limited thereby.

Although the present invention has been described in detail above with reference to the presented embodiments, those skilled in the art will be able to make various variations and modifications without departing from the technical spirit of the present invention by referring to the presented embodiments. . The present invention is not limited by such variations and modifications, but is limited by the claims appended below.

41: Noche 42: Burner
43: Door 44: Insertion Shooter
45: supply induction unit 46: storage tank
47: Hopper 48: Screw Conveyor
49: elevator

Claims (5)

A furnace body (41) with a combustion space formed therein;
A burner 42 that initiates combustion inside the furnace body 41;
A door 43 formed on the furnace body 41; and
It includes a supply means for supplying aluminum secondary dross dust into the interior of the furnace body 41,
The inner wall of the furnace body 41 is made of a refractory material that can withstand a temperature of at least 1800 ° C,
It further includes a dust separation unit 24 that separates aluminum secondary dross dust of a predetermined diameter or less from the secondary dross remaining after the aluminum is separated from the primary aluminum dross,
A calciner for aluminum secondary dross processing, characterized in that aluminum secondary dross dust is spontaneously combusted by the start of ignition of the burner 42 within the furnace body 41 to generate a reaction product containing aluminum oxide as a main component. The method of claim 1, wherein the door 43 has a swing structure or an up-down structure, and the supply means is an aluminum secondary dross treatment including an input chute 44 flowing into the interior of the furnace body 41. Yong calcining furnace. The method according to claim 1, wherein the supply means includes a hopper (47) connected to a transfer screw for transferring aluminum secondary dross dust; an elevator 49 extending vertically from the hopper 47; a storage tank 46 for storing secondary dross dust transported along the elevator 49; And a calciner for aluminum secondary dross processing, including a supply induction unit (45) that injects the secondary dross dust stored in the storage tank (46) into the interior of the furnace body (41). In the method of processing aluminum secondary dross,
Cooling and pulverizing the reprocessed dross residue while transporting it;
Separating dross dust of a predetermined diameter or less from the pulverized secondary dross;
Injecting dross dust into the interior of a calcining furnace in which combustion initiation means is installed;
Inducing a spontaneous combustion reaction of dross dust by initiating ignition of a burner inside the calcining furnace; and
A method of treating secondary dross comprising the step of generating a reactant containing aluminum oxide as a main component by combustion of dross dust. The method of treating secondary dross according to claim 4, wherein calcium oxide or solid fluorine is added for pollution-free treatment of the reaction product of dross dust.