KR102081310B1 - System and method for aluminium melting and black dross recycling - Google Patents

Abstract

The present invention relates to a method for recycling black dross which can increase aluminum scrap melting efficiency. The method comprises: (a) a step of crushing and grinding black dross, which is created by fluxing aluminum scrap by flux containing sodium chloride and potassium chloride when melting the aluminum scrap in molten aluminum, to divide the black dross into aluminum grains and dross particle powder; (b) a step of causing a hydrolysis reaction between the dross particle powder and water to create a water solution in which a soluble solid containing sodium chloride and potassium chloride is dissolved; and (c) a step of using each of a plurality of evaporation modules to evaporate the water included in the water solution to extract the soluble solid from the water solution, wherein evaporation of the water is induced under different environmental conditions for the evaporation modules to extract the sodium chloride and the potassium chloride in accordance with different extraction orders and extraction times for the evaporation modules.

Description

System and method for aluminum melting and black dross recycling}

The present invention relates to an aluminum melting and black dross recycling system and method for carrying out the aluminum scrap melting process and the black dross recycling process.

Many aluminum parts used in automobiles, home appliances, and building materials are manufactured using aluminum casting equipment. It is aluminum melting furnace to supply molten aluminum to such an aluminum casting apparatus. Aluminum melting furnace is a device that melts aluminum scrap formed into a certain size at high temperature.

Conventional aluminum melting furnaces include a heating chamber including a burner for heating aluminum molten metal, a molten metal stirring chamber including a molten metal pump for pumping the aluminum molten metal discharged from the heating chamber, and the aluminum molten metal discharged from the molten metal stirring chamber. A charging chamber for charging the chip chunks.

Here, the aluminum compressed chip agglomerate is also referred to as aluminum ingot, and is a compression of a large number of aluminum chips that are frequently generated during production or processing of aluminum products. However, the aluminum compressed chip agglomerates contain a plurality of pores in the process of compressing the aluminum chips. Therefore, in the conventional aluminum melting furnace, heat cannot be transferred well to the center of the aluminum compressed chip agglomerate put into the molten aluminum, so that the melting efficiency decreases, and the aluminum compressed chamber agglomerate floats on the surface of the aluminum molten metal and comes into contact with the atmosphere to produce aluminum oxide. There was a problem.

Conventional aluminum melting furnace, in order to solve the above problems, the aluminum compacted chip lump is put into the molten aluminum pumped in the molten metal stirring chamber and then transferred to the charging chamber, but in this case, the aluminum compacted chip mass is still alumina due to the low specific gravity of the aluminum compacted chip. Melting proceeds with the compressed chip lump suspended in the molten aluminum. Therefore, the conventional aluminum melting furnace has a problem that the melting efficiency is lowered, and the amount of aluminum oxide generated is large and the real rate of pure aluminum is lowered.

On the other hand, aluminum is a highly oxidizing metal, so aluminum oxide is generated in the process of dissolving aluminum in the molten aluminum. If the generation amount of such aluminum oxide increases, the recovery rate of aluminum falls. In addition, in general, the aluminum lump to be added to the molten aluminum is interposed with paint and other inclusions. As these inclusions increase, the purity of aluminum decreases.

In order to solve the problems caused by the aluminum oxide and inclusions, a flux (F) capable of preventing oxidation of aluminum and capturing the inclusions is added to the aluminum molten metal. The dross generated by flux treatment of the molten aluminum in this way is called black dross.

However, in the related art, a method for effectively recycling the black dross has not been proposed so that materials contained in the black dross such as aluminum, aluminum oxide, and flux may be recycled according to a purpose. Therefore, the black dross is disposed of and disposed of in the soil, which causes a problem of environmental pollution and resource waste.

The present invention has been made to solve the above problems, and an object thereof is to provide an aluminum dissolution and black dross recycling system having an improved structure to increase dissolution efficiency of aluminum scrap.

Furthermore, an object of the present invention is to provide an aluminum dissolution and black dross recycling system having an improved structure to reduce the amount of aluminum oxide produced.

Furthermore, an object of the present invention is to provide an aluminum dissolution and black dross recycling system having an improved structure to increase dissolution recovery rate of pure aluminum.

Furthermore, an object of the present invention is to provide an aluminum melting and black dross recycling system whose structure is improved to facilitate recycling of materials contained in the black dross.

Furthermore, an object of the present invention is to provide an aluminum dissolution and black dross recycling system, which is capable of smoothly recovering chloride salts contained in the flux for flux treating aluminum scrap from the black dross.

The black dross recycling method according to a preferred embodiment of the present invention for solving the above problems, (a) when dissolving aluminum scrap in the molten aluminum, the aluminum scrap is fluxed by a flux containing sodium chloride and potassium chloride Crushing and pulverizing the generated black dross into aluminum granules and dross particulate powder; (b) hydrolyzing the dross particulate powder with water to produce an aqueous solution in which soluble solids containing sodium chloride and potassium chloride are dissolved; And (c) evaporating the water contained in the aqueous solution using a plurality of evaporation modules, respectively, to precipitate the soluble solids from the aqueous solution, inducing the evaporation of the water under different environmental conditions for each of the evaporation modules, thereby evaporating the water. Precipitating the sodium chloride and the potassium chloride according to the different precipitation order and precipitation timing for each module.

Preferably, in the step (c), each of the evaporation module, after heating the aqueous solution to a predetermined reference temperature using a reboiler, the evaporator is adjusted so that the evaporation temperature of the water to the reference temperature using an evaporator Evaporation of the water is induced under the internal pressure of to precipitate the soluble solids.

Preferably, the reference temperature is individually determined for each of the evaporation modules according to the order of precipitation and the time of precipitation of the sodium chloride and potassium chloride to be implemented in the evaporation module among the evaporation modules.

Preferably, in step (c), the evaporation module of at least one of the evaporation modules, the solubility of the sodium chloride in the aqueous solution using the reboiler is more than a predetermined first reference value compared to the solubility of the potassium chloride. After heating the aqueous solution to a first reference temperature lowered by as much as possible, by using the evaporator to induce the evaporation of the water under the internal pressure of the evaporator is adjusted so that the evaporation temperature of the water to the first reference temperature, so that the sodium chloride It precipitates preferentially compared with the said potassium chloride.

In the step (c), the evaporation module of at least one of the evaporation module, the difference between the solubility of the sodium chloride and the solubility of the potassium chloride in the aqueous solution by using the reboiler is lower than a second predetermined reference value or less After heating the aqueous solution to a second reference temperature, the evaporator induces the evaporation of the water under an internal pressure of the evaporator, in which the evaporation temperature of the water is adjusted to the second reference temperature, thereby reducing the sodium chloride and the potassium chloride. Precipitate together.

Preferably, in step (c), the evaporation module of at least one of the evaporation modules, the solubility of the potassium chloride in the aqueous solution using the reboiler is less than a predetermined third reference value compared to the solubility of sodium chloride. After heating the aqueous solution to a third reference temperature lowered to, the potassium chloride is preferentially compared to the sodium chloride under the internal pressure of the evaporator wherein the evaporator temperature of the water is adjusted to the third reference temperature using the evaporator. Precipitate.

In step (c), the evaporation module of at least one of the evaporation modules is a vacuum pressure selectively applied from the pressure regulating member so as to induce a reduced pressure evaporation of the water in a vacuum atmosphere according to the predetermined reference temperature. This maintains the internal pressure of the evaporator in a vacuum.

Preferably, (d) further comprises the step of centrifuging the soluble solid precipitate precipitated from the aqueous solution and the aqueous solution mixed with the soluble solid precipitate, wherein in step (c), the evaporation modules are reused to obtain the In step), the soluble solids are reprecipitated from the aqueous solution separated from the soluble solids precipitate.

Preferably, (e) further comprising the step of drying and storing the soluble solid precipitate separated from the aqueous solution in step (d).

Preferably, in step (c), the evaporation module of at least one of the evaporation modules, heat the aqueous solution by heat-exchanging the original steam and the aqueous solution supplied from an external steam source, in the step (c) The evaporation module of at least another one of the evaporation modules may be generated by evaporation of the water generated by the evaporation of the water in the at least one evaporation module or by evaporation of the water by another evaporation module of the evaporation modules. The aqueous solution is heated by heat-exchanging the generated steam and the aqueous solution.

Preferably, (f) further comprising the step of centrifuging the insoluble solids and the aqueous solution dispersed or precipitated in the aqueous solution, in the step (c), using the evaporation modules, from the aqueous solution separated from the insoluble solids The soluble solids are precipitated.

Preferably, (g) the aqueous solution in step (f) using the condensed water produced by cooling the original steam or the generated steam by the aqueous solution or the condensed water produced by condensing the original steam or the generated steam by a condenser. It further comprises the step of washing the insoluble solids separated from.

The aluminum melting and black dross recycling system and method according to the present invention has the following effects.

First, the present invention is the aluminum metal contained in the black dross by forming a spherical black dross by forming a spherical black dross by splicing the black dross generated by the flux selectively trapping non-metallic inclusions (vortex) It can reduce the amount of can increase the recovery rate of the dissolution of pure aluminum.

Second, the present invention can improve economics by recycling the economically valuable materials contained in the spherical black dross.

Third, the present invention recycles the materials contained in the spherical black dross to aluminum granules, soluble solids, insoluble solids and hydrolyzed gases according to their characteristics, and discards them without recycling among the materials contained in the spherical black dross. Economics can be further improved by minimizing the materials to be added.

Fourth, the present invention, by using a plurality of evaporation modules individually to precipitate the chloride salts contained in the soluble solids in various ways from the aqueous solution produced by hydrolysis reaction of the black dross, the high value-added potassium chloride, other flux Chloride salts as components can be recycled more effectively.

1 is a block diagram schematically illustrating an aluminum melting and black dross recycling system according to a preferred embodiment of the present invention.
FIG. 2 is a schematic diagram schematically showing the aluminum melting furnace of FIG. 1. FIG.
3 is a cross-sectional view of the melting chamber and the flow force applying chamber of FIG. 2.
FIG. 4 is a schematic diagram showing a state in which a spherical black dross is formed in the dissolution chamber of FIG. 2. FIG.
5 is a photograph of a spherical black dross formed in the dissolution chamber of FIG. 2.
6 is a plan view of a melting chamber showing a state in which a spherical black dross is suspended on the surface of the molten aluminum contained in the melting chamber of FIG. 2.
7 is a schematic diagram schematically showing the black dross recycling apparatus of FIG.
8 is a photograph of atomized dross powder.
9 is a schematic diagram schematically showing the configuration of the precipitation unit of FIG.
10 is a solubility graph of an aqueous chloride salt solution.
11 is a photograph of soluble solids precipitated and dried.
12 is a SEM-EDS chart qualitatively analyzing the soluble solids shown in FIG. 11.
FIG. 13 is a table showing a composition ratio of soluble solids shown in FIG. 11. FIG.
14 is a photograph of insoluble solids dried.
15 is a photograph of insoluble solids subjected to calcining treatment
FIG. 16 is a SEM-EDS chart qualitatively analyzing the insoluble solids subjected to the calcination shown in FIG. 15.
FIG. 17 is a graph showing the composition ratio of insoluble solids subjected to calcining treatment shown in FIG. 15. FIG.
18 is a flow chart schematically showing a method for dissolving aluminum and recycling black dross according to another preferred embodiment of the present invention.
FIG. 19 is a flowchart for explaining details of the aluminum dissolving step and the step of crushing and crushing the spherical black dross described in FIG. 18. FIG.
20 is a flow chart for explaining the details of the dross powder water decomposition step and the water decomposition product recycling step described in FIG.

The terms or words used in this specification and claims are not to be construed as being limited to the common or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meanings and concepts corresponding to the technical idea of the present invention based on the principle that the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

In the drawings, the size of each component or a specific portion constituting the components is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. Thus, the size of each component does not entirely reflect its actual size. If it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, such description will be omitted.

1 is a block diagram schematically showing an aluminum melting and black dross recycling system according to a preferred embodiment of the present invention.

Referring to FIG. 1, an aluminum melting and black dross recycling system 1 according to a preferred embodiment of the present invention includes an aluminum melting furnace 2 for dissolving aluminum scrap in a fluxed aluminum molten metal; And a black dross recycling apparatus 3 for recycling the black dross formed by trapping inclusions contained in the aluminum molten metal in the flux when the aluminum scrap is dissolved in the aluminum molten metal. This aluminum melting and black dross recycling system (1) dissolves aluminum scrap in fluxed aluminum molten metal so as to secure aluminum molten metal for producing an aluminum casting, and recycles the components contained in the black dross. It's meant to handle black dross so you can.

Hereinafter, for convenience of description, the aluminum melting furnace 2 will be described first, and then the black dross recycling apparatus 3 will be described.

FIG. 2 is a schematic view schematically showing the aluminum melting furnace of FIG. 1.

Referring to FIG. 2, the aluminum melting furnace 2 includes a heating chamber 10 in which aluminum molten metal M is heated, and a melting chamber in which aluminum scraps A and flux F are introduced into aluminum molten metal M, respectively. 20 and a flow force imparting chamber 20 for imparting a flow force to the molten aluminum M.

As shown in FIG. 2, the aluminum melting furnace 2 has a plurality of spaces partitioned by walls having a refractory material. The heating chamber 10, the melting chamber 20, and the flow force imparting chamber 30 are each provided in a state independent of other spaces in any one of a plurality of spaces of the aluminum melting furnace 2.

The heating chamber 10 is a space for heating the molten aluminum M to a predetermined temperature.

The heating chamber 10 communicates with the 2nd flow path 29 of the melting chamber 20 mentioned later, and receives the aluminum molten metal M from the melting chamber 20. The heating chamber 10 is formed in a hermetically sealed structure that is separated from the outside except for a portion connected to the first flow passage 16 and the second flow passage 29 which will be described later to minimize heat loss.

As shown in FIG. 2, the heating chamber 10 includes a heating unit 12 for heating the aluminum molten metal M and a hot water outlet for discharging the aluminum molten metal M to the outside of the aluminum melting furnace 2. 14 and a first flow passage 16 for transferring the molten aluminum M accommodated in the heating chamber 10 to the flow force applying chamber 30.

The heating unit 12 is a device for heating the molten aluminum M to a predetermined temperature.

As shown in FIG. 2, the heating unit 12 may be a burner installed in the walls partitioning the heating chamber 10. The heating temperature of the aluminum molten metal M is not specifically limited. The temperature of the aluminum molten metal M may be measured by a temperature sensor (not shown) installed in the heating chamber 10, and the heating unit 12 receives the temperature of the aluminum molten metal M from the temperature sensor, thereby causing aluminum. The molten metal M can be heated to a predetermined heating temperature.

The hot water outlet 14 is an outlet for discharging the molten aluminum M heated in the heating chamber 10 to the outside of the aluminum melting furnace 2.

 The tap opening 14 may be connected with an aluminum casting apparatus for producing an aluminum casting or with a molten metal transfer container for transferring an aluminum molten metal M. FIG. In the tap opening 14, an opening and closing valve 18 for selectively opening and closing the tap opening 14 may be provided.

The first flow passage 16 is a passage for transferring the molten aluminum M accommodated in the heating chamber 10 to the flow force applying chamber 30.

As shown in FIG. 2, the first flow passage 16 is formed by penetrating a wall partitioning the heating chamber 10 and the flow force applying chamber 30, and the aluminum molten metal M is formed in the first flow passage ( 16) flows into the flow force providing chamber (30).

3 is a cross-sectional view of the dissolution chamber and the flow force imparting chamber illustrated in FIG. 2, illustrating a spherical black dross formed in the dissolution chamber of FIG. 2 illustrated in FIG. 4, and the dissolution of FIG. 2 illustrated in FIG. 5. Picture of spherical black dross formed from yarn.

The melting chamber 20 is a space for injecting the flux F and the aluminum scrap A into the molten aluminum M. As shown in FIG.

The melting chamber 20 communicates with the 3rd flow path 34 of the flow force provision chamber 30 mentioned later, and receives the molten aluminum M from the flow force provision chamber 30. The melting chamber 20 is formed in an open structure in which at least a portion of the upper surface is opened to inject the flux F and the aluminum scrap A into the molten aluminum M, and is smaller than the heating chamber 10. Has a volume. That is, the melting chamber 20 is formed in an open structure so that the aluminum scrap A may be injected into the melting chamber 20 to perform the dissolving operation, and the heating chamber 10 may be relatively smaller than the heating chamber 10 to reduce the heat loss. It has a small volume.

As shown in FIG. 2 and FIG. 3, the melting chamber 20 includes a vortex unit 21 for generating a swirl V descending in the molten aluminum M, and the flux F through the vortex V. The heating chamber 10 includes a flux supply unit 23 to be introduced into the raw material, a raw material supply unit 25 to inject aluminum scrap A into the vortex V, and an aluminum molten metal M contained in the melting chamber 20. And a second flow passage 29 for delivery therethrough.

The vortex unit 21 is a member for forming the vortex V which swings and descends on the molten aluminum M accommodated in the melting chamber 20.

The vortex unit 21 is installed in the melting chamber 20 so that at least a part thereof is immersed in the molten aluminum M. In the case where the flow of the vortex V generated by the vortex unit 21 and the flow of the aluminum molten metal M flowing into the melting chamber 20 through the third flow passage 34 directly face each other, the aluminum melt M ) Flow may be disturbed. In order to prevent this, as shown in FIG. 2, the vortex unit 21 is preferably installed on one side of the melting chamber 20 so as not to be in line with the third flow passage 34, but is limited thereto. It is not.

As shown in FIG. 3, the vortex unit 21 has a rotary shaft having a lower end immersed in the aluminum molten metal M and an upper end extended out of the aluminum molten metal M and axially coupled to a driving motor (not shown). 21a) and a stirring impeller 21b axially coupled to the lower end of the rotation shaft 21a. As shown in FIG. 3, when the driving motor is driven, the stirring impeller 21b is rotated about the rotation shaft 21a to pivot about the rotation shaft 21a in the aluminum molten metal M accommodated in the melting chamber 20. A descending vortex V is produced.

The flux supply unit 23 is a device for injecting the flux F supplied from an external flux supply source (not shown) into the molten aluminum M accommodated in the melting chamber 20.

Flux F is a mixed salt having a specific gravity smaller than that of aluminum, and is formed of a material having a high affinity for inclusions. As shown in FIG. 3, the flux supply unit 23 injects the flux F into the vortex V generated by the vortex unit 21. Then, the flux (F) is rapidly immersed in the molten aluminum (M) by the vortex (V) to dissolve and can be evenly spread in the dissolution chamber (20). However, the present invention is not limited thereto, and the flux supply unit 23 may inject the flux F into a portion other than the vortex V.

The flux (F) injection timing is not particularly limited. For example, the flux supply unit 23 can inject the flux F into the vortex V before the raw material supply unit 25 injects the aluminum scrap A into the vortex V. As shown in FIG. Then, the flux F is immersed and melt | dissolved in the molten aluminum M while turning down by vortex V. However, since the flux F has a specific gravity smaller than that of aluminum, the flux F dissolved in the aluminum molten metal M rises to the surface of the aluminum molten metal M, and the molten flux layer is formed on the surface of the aluminum molten metal M. That is, a salt bath layer is formed. Such a molten flux layer can block the aluminum molten metal M and the aluminum script A injected into the molten aluminum M from contacting oxygen in the air, thereby reducing the amount of aluminum oxide generated.

Such flux F has a composition capable of selectively trapping inclusions and forming a molten flux layer. Preferably, the flux (F) may include 93-97 parts by weight of a mixture of sodium chloride (NaCl) and potassium chloride (KCl) in the same parts by weight and 3-7 parts by weight of cryolite (Cryolite, Potassium Cryolite). More preferably, the flux (F) may include 47.5 parts by weight of sodium chloride (NaCl), 47.5 parts by weight of potassium chloride (KCl) and 5 parts by weight of potassium aluminum fluoride (KAlF ₄ ).

On the other hand, when the input of aluminum scrap A is started by the raw material supply unit 25 which will be described later, the flux supply unit 23 vortex flux F simultaneously or at the same time as the raw material supply unit 25. You can put it in That is, the flux F is continuously or intermittently supplied in accordance with the supply trend of the aluminum scrap A even after the introduction of the aluminum scrap A is started.

The flux (F) is preferably supplied with the same amount as the amount of inclusions to be captured using this, but is not limited thereto. Therefore, the supply amount of flux F can be adjusted according to the supply amount of aluminum scrap A and the kind of aluminum scrap A. FIG. That is, when aluminum scrap A containing a large amount of paint or other inclusions is supplied, the supply amount of flux F is increased, and when aluminum scrap A with high purity is supplied, the supply amount of flux F is supplied. Can be reduced.

The raw material supply unit 25 is an apparatus for injecting the aluminum scraps A supplied from an external raw material supply source (not shown) into the molten aluminum M accommodated in the melting chamber 20.

As shown in FIG. 3, the raw material supply unit 25 injects aluminum scrap A into the vortex V generated by the vortex unit 21. Then, the aluminum scrap (A) can be rapidly immersed in the molten aluminum (M) and dissolved while turning down by the vortex (V), the contact between the aluminum scrap (A) immersed in the aluminum molten metal (M) is further contacted. By effectively blocking, the amount of aluminum oxide generated can be further reduced.

The injection timing of aluminum scrap (A) is not specifically limited. For example, the raw material supply unit 25 may start to input aluminum scrap A after the molten flux layer is formed on the surface of the aluminum molten metal M. For example, as shown in FIG. Then, the aluminum scrap (A) may be immersed in the aluminum molten metal (M) in a state where a molten flux layer is formed on the surface of the aluminum molten metal (M). For this reason, since the contact between the aluminum scrap A immersed in the molten aluminum M and the atmosphere is more effectively blocked, the amount of aluminum oxide can be further reduced.

If the diameter of the aluminum scrap (A) is large, there is a problem that the heat transfer rate is lowered. Therefore, it is preferable that aluminum scrap (A) has a diameter of 5 cm or less. The kind of such aluminum scrap (A) is not specifically limited. For example, the aluminum scraps A may be aluminum waste can scraps (UBCs, A 3XXX series, A 5XXXX series) mainly comprising aluminum, magnesium and aluminum alloys. The chemical composition of this aluminum waste can scrap is shown in Table 1.

part Al alloy
line Chemical composition (%) Si Fe Cu Mn Zn Mg Body A 3004 <0.3 <0.70 <0.25 1.0-1.5 <0.25 0.8-1.3 Lid A 5052 <0.25 <0.40 <0.10 <0.10 <0.10 2.2-2.8 Tab A 5182 <0.2 <0.35 <0.15 0.2-0.5 <0.25 4.0-5.0

On the other hand, inclusions (inclusions) of the aluminum scrap (A), when the aluminum scrap (A) is charged and dissolved in the aluminum molten metal (M), has a property to aggregate with the molten aluminum. By the way, the molten flux layer, ie, flux F, weakens the cohesion between inclusions and molten aluminum to dissociate inclusions and molten aluminum, and selectively captures molten aluminum and dissociated inclusions to form black dross B ₁ . do. The black dross (B ₁ ) has a specific gravity lower than that of molten aluminum due to an increase in volume in the above-described forming process, thereby rising to the surface of the molten aluminum (M).

In addition, as shown in FIGS. 3 and 4, the black dross B ₁ is swung down by the vortex V and then is released from the vortex V when the lower end of the vortex V is reached. After rising to the surface of the aluminum molten metal (M) is joined to the vortex (V) by the suction force of the vortex (V) again. Thus, the black dross (B ₁₎ is coupled with the surface of the other black dross (B ₁₎ generated in the aluminum molten metal (M) through this process. As shown in FIG. 5, when this process is repeated, a spherical black dross B ₂ in which a plurality of black dross B ₁ is spherically collected is formed. That is, the vortex unit 21 repeatedly lowers and floats the black dross B ₁ through the vortex V to form a spherical black dross B in which a plurality of black dross B ₁ is spherically collected. ₂ ) to form. The chemical composition of such spherical black dross (B ₂ ) is not specifically limited. For example, as described above, aluminum scrap (A) is aluminum waste can scrap (UBCs scrap) and flux (F) is 47.5 parts by weight sodium chloride (NaCl), 47.5 parts by weight potassium chloride (KCl) and potassium aluminum fluoride ( KAlF ₄ ) 5 parts by weight. The chemical composition of the spherical black dross (B ₂ ) is shown in Table 2.

Chemical composition Chemical composition (%) Al 5-10 Al ₂ O ₃ 25-35 Mg 5-10 MgO 5-10 NaCl 20-30 KCl 20-30

Spherical black dross (B ₂ ) is a common black dross formed once without black dross (B ₁ ) gradually descending and floating the aluminum molten metal (M), without such a drop and injury process. Compared to the removal of inclusions is superior. Because of this, the case of forming the spherical black dross (B ₂₎ may be reduced with aluminum content in the dross in comparison with the case of forming the common black dross. That is, a general black dross, for example, a general black dross formed by fluxing white dross in a conventional aluminum waste can melting process has an aluminum content of about 50% or more, but a spherical black dross (B ₂ ) is about It has a content rate of aluminum of 10% or less. Therefore, by forming spherical black dross (B ₂ ), the dissolution recovery rate of pure aluminum can be improved. In addition, by forming the spherical black block dross (B2), it is possible to omit the dross reprocessing process for recovering the aluminum trapped in the dross by reprocessing the dross using a heating agent flux and a reprocessing indenter. The cost of reprocessing can be reduced.

The second flow passage 29 is a passage for transferring the molten aluminum M in which the aluminum scrap A is dissolved, to the heating chamber 10.

As shown in FIG. 2, the second flow passage 29 is formed by penetrating a wall partitioning the melting chamber 20 and the heating chamber 10, and the aluminum molten metal M is formed in the second flow passage 29. It is introduced into the heating chamber 10 through.

Next, the flow force provision chamber 30 is a space for applying flow force to the molten aluminum M so that the aluminum molten metal M can circulate between the heating chamber 10 and the melting chamber 20.

The flow force imparting chamber 30 communicates with the first flow passage 16 of the heating chamber 10 to receive the aluminum molten metal M from the heating chamber 10.

As shown in FIG. 2, the flow force applying chamber 30 is preferably provided between the first flow passage 16 and the dissolution chamber 20 of the heating chamber 10. However, the present invention is not limited thereto, and the flow force applying chamber 30 may be installed between the second flow passage 29 and the heating chamber 10 of the dissolution chamber 20.

As shown in FIG. 2 and FIG. 3, the flow force applying chamber 30 accelerates the aluminum molten metal M to impart a flow force to the aluminum molten metal M, and the flow force is imparted. And a third flow passage 34 for transferring the melted aluminum M to the dissolution chamber 20.

The acceleration unit 32 is provided in the flow force provision chamber 30 so that at least one part may be immersed in the molten aluminum M. FIG. For example, as shown in FIG. 3, the acceleration unit 32 receives a driving force from a driving motor (not dosing) provided outside of the flow force applying chamber 30, and supplies it to the flow force applying chamber 30. It may be a melt pump capable of circulating the received molten aluminum (M).

The third flow passage 34 is a passage for transferring the molten aluminum M applied with the flow force by the acceleration unit 32 to the flow force applying chamber 30.

As shown in FIGS. 2 and 3, the third flow passage 34 penetrates so that the lower part of the wall partitioning the flow force imparting chamber 30 and the dissolution chamber 20 faces the impeller of the acceleration unit 32. The molten aluminum M is introduced into the dissolution chamber 20 through the third flow passage 34.

In the present specification, the flow force applying chamber 30 having the acceleration unit 32 is provided between the heating chamber 10 and the melting chamber 20, but the present invention is not limited thereto. That is, the vortex unit 20 of the melting chamber 20 forms the vortex V to raise and lower the aluminum molten metal M, and at the same time, transmit the flow force for circulating the aluminum melting furnace 2 to the aluminum molten metal M. FIG. Since it can be provided, the flow force provision chamber 30 and the acceleration unit 32 provided in this can be abbreviate | omitted.

6 is a plan view of a melting chamber showing a state in which a spherical black dross is suspended on the surface of the molten aluminum contained in the melting chamber of FIG. 2.

When a large number of spherical black dross (B ₂ ) is concentrated in the vortex (V), the lowering and floating action of the spherical black dross (B ₂ ) by the vortex (V) is weakened and the spherical black dross (B ₂ ) There is a fear that the formation efficiency of the amine may be reduced. Therefore, it is preferable to adjust the density of the spherical black dross B ₂ located in the vortex V to an appropriate level by releasing the spherical black dross B ₂ grown by a predetermined reference diameter from the vortex V.

Based on the diameter of the spherical black dross (B ₂₎ it is not particularly limited. For example, aluminum scrap (A) is aluminum waste can scrap (UBCs scrap) and flux (F) is 47.5 parts by weight of sodium chloride (NaCl), 47.5 parts by weight of potassium chloride (KCl) and 5 parts of potassium aluminum fluoride (KAlF ₄ ). In the case of including the part, the reference diameter of the spherical black dross B ₂ is 2 cm to 5 cm.

In order to separate the spherical black dross B ₂ grown by the reference diameter from the vortex V, the dissolution chamber 20 separates the spherical black dross B ₂ from the vortex V ( 27) may further include.

As shown in FIG. 3, the separation unit 27 has a separation plate having a shape capable of pulling a spherical black dross B ₂ suspended on the surface of the aluminum molten metal M away from the vortex V. 27a, and a connecting rod 27b connecting the driving device (not shown) and the separator 27a. Here, the drive device is preferably a work vehicle provided outside the melting chamber 20, but is not limited thereto.

As the separation unit 27 is provided in this way, the spherical black dross B ₂ having a predetermined reference diameter may be pulled away from the vortex V using the separation plate 27a to separate from the vortex V. Can be. Therefore, since the spherical black dross B ₂ is concentrated, the formation efficiency of the spherical black dross B ₂ can be prevented from falling. Here, the separation unit 27 may also perform a function of discharging the spherical black dross (B ₂ ) from the molten aluminum (M) to the outside.

On the other hand, as shown in FIG. 6, when the spherical black dross B ₂ is pulled away from the vortex V using the separation unit 27, the molten aluminum M accommodated in the dissolution chamber 20 is obtained. The surface of) is covered with a spherical black dross (B ₂ ) deviating from the vortex (V). Therefore, the aluminum molten metal M contained in the melting chamber 20 is blocked from the atmosphere by the spherical black dross B ₂ covering the molten aluminum 20, and the spherical black dross B ₂ is the aluminum molten metal contained in the melting chamber 20. It has a thermal effect on (M). Therefore, being a heat loss of the aluminum molten metal (M) minimized by the rectangular black dross (B _2), the molten aluminum compared with the case the aluminum molten metal (M) is not covered by the spherical black dross (B ₂₎ (M Temperature rises.

In the conventional aluminum melting furnace, the temperature of the aluminum molten metal M contained in the melting chamber is generally about 700 ° C. or less, whereas the temperature of the aluminum molten metal M contained in the melting chamber 20 is about 730 ° C. or more. Can be raised. For this reason, in the aluminum melting furnace 2, the melting efficiency of aluminum scrap (A) can be further improved compared with the conventional aluminum melting furnace.

7 is a schematic view schematically showing the black dross recycling apparatus of FIG. 1.

When the aluminum scrap (A) is dissolved using the aluminum melting furnace (2) described above, a spherical black dross (B ₂ ) in which the black dross (B ₁ ) is spherically aggregated is formed. Spherical black dross (B ₂ ) contains not only a certain percentage of aluminum but also economically valuable materials such as aluminum oxide, flux (F), etc. . Therefore, when the spherical black dross (B ₂ ) is disposed of as it is without reprocessing through landfilling or the like, materials contained in the spherical black dross (B ₂ ) cannot be recycled, thereby reducing economic efficiency. Spherical black dross (B ₂ ) may cause environmental pollution.

To solve this problem, an aluminum melting and black dross recycling system (1), spherical black dross (B ₂₎ a spherical black to recycle the materials contained in the dross (B ₂₎ a black to enable recycling process It includes a dross recycling device (3).

As shown in FIG. 7, the black dross recycling apparatus 3 breaks and crushes the spherical black dross B ₂ and breaks it into pieces of aluminum grains N and dross fine powder P ₂ . A water decomposition unit 50 which decomposes the pulverization unit 40 and the dross fine particle powder P ₂ with water by water decomposition reaction to decompose it into soluble solids (S), insoluble solids (I) and hydrolysis gas (G); , The precipitation unit 60 for concentrating the aqueous solution Q in which the soluble solids S are dissolved so that the soluble solids S is precipitated, and the soluble solids storage for drying and storing the precipitates S ₁ of the soluble solids S. The unit 70, an aluminum granule storage unit for storing the aluminum grains N, an insoluble solids storage unit 90 for drying and firing the insoluble solids I, and a hydrolyzed gas G It may include a gas storage unit 100 for storing.

First, the crushing / crushing unit 40 is an apparatus for crushing and crushing spherical black dross B ₂ .

Crushing / milling unit 40, the aluminum grains (N) and dross powder (P ₁₎ of the lysate of the crusher 41, and a rectangular black dross (B ₂₎ for crushing the spherical black dross (B ₂₎ the first separating member 42 and the dross powder, aluminum granules (N) and a grinder (43) of the pulverized product of the grinder 43, and a dross powder (P ₁₎ crushing (P ₁₎ to separate the It may include a second separation member 44 which is pulverized by the fine particles to separate the fine particles dross (P ₂ ).

The crusher 41 is an apparatus for crushing the spherical black dross B ₂ and dividing it into aluminum grains N and dross powder P ₁ .

Among the aluminum particles and aluminum alloy particles included in the spherical black dross (B ₂ ), the relatively large particle sizes and the aluminum alloy particles are agglomerated due to the heat generated when the spherical black dross (B ₂ ) is broken. Aluminum Granules and Aluminum Alloy Granules. In addition, among the aluminum particles and the aluminum alloy particles included in the spherical black dross (B ₂ ), the aluminum particles and the aluminum alloy particles having relatively small particle sizes are not aggregated to become aluminum powder and aluminum alloy powder. For convenience of explanation, hereinafter, aluminum grains N and aluminum alloy grains will be collectively referred to as aluminum grains N. FIG.

The crusher 41 breaks the spherical black dross B ₂ supplied from the aluminum melting furnace 2 by using the characteristics of the aluminum particles described above, and divides it into aluminum grains N and dross powder P ₁ . do. The dross powder P ₁ includes the remaining materials in the form of powder except for the relatively large particle size aluminum particles of the spherical black dross B ₂ .

The first separating member 42 is a member for separating the aluminum grains N and the dross powder P _{1 from} the crushed products of the spherical black dross B ₂ .

The structure of the first separating member 42 is not particularly limited. For example, the first separating member 42 may be composed of a vibrating screen having a predetermined first reference particle size. The first reference particle size is preferably about 10 mm, but is not limited thereto.

After the first separating member 42 separates the aluminum grains N and the dross powder P ₁ , the aluminum grains N are transferred to the aluminum storage unit and the dross powder P ₁ . Passes to the grinder 43.

The crusher 43 is an apparatus for crushing dross powder P ₁ and dividing it into aluminum grains N and dross fine particle powder P ₂ .

Among the materials included in the dross powder (P ₁ ), insoluble solids (I) such as aluminum oxide and magnesium oxide are preferably atomized in order to easily recycle them. Therefore, the grinder 43 for grinding and atomizing the dross powder P ₁ is provided.

However, some of the aluminum particles included in the dross powder P ₁ may be agglomerated while the dross powder P ₁ is pulverized using the grinder 43 to produce aluminum grains N. Therefore, the crusher 43 grinds the dross powder P ₁ received from the first separating member 42, and divides the dross powder P ₁ into aluminum grains N and the finely divided dross fine powder P ₂ .

The second separating member 44 is a member for separating the aluminum grains N and the dross fine particle powder P _{2 from} the pulverized product of the dross powder P ₁ .

The structure of the second separating member 44 is not particularly limited. For example, the second separating member 44 may be configured as a trommel screen having a predetermined second reference particle size. The second reference particle size is preferably 0.5 mm, but is not limited thereto.

The second separating member 44 separates the aluminum grains N and the dross fine powder P ₂ received from the grinder 43, and then transfers the aluminum grains N to the aluminum grain storage unit. In addition, the dross particulate powder P ₂ is transferred to the water decomposition unit 50.

8 is a photograph of dross particulate powder.

Next, the water decomposition unit 50 is an apparatus for water-decomposing the dross fine particle powder P ₂ received from the 2nd separating member 44.

As shown in FIG. 8, the dross particulate powder P ₂ is a dark gray powder including materials having various physicochemical properties such as flux (F), aluminum, aluminum-magnesium alloy, magnesium and oxide. Take form.

Since this dross particulate powder (P ₂₎ preferably the conversion and decomposition in order to recycle the materials to facilitate the recycling of the materials contained in the dross fine powder (P ₂₎ contained in the To this dross fine powder (P ₂ ) Is provided with a water decomposition unit 50 capable of water decomposition.

The water decomposition unit 50 includes dross fine powder P such that the dross fine particle powder P ₂ undergoes water decomposition reaction with water to be decomposed into soluble solids S, insoluble solids I, and hydrolysis gas G. ₂ ) a reactor 52 for stirring water and a gas collector 54 for collecting hydrolysis gas G, and a first centrifuge 56 for centrifuging an aqueous solution Q and an insoluble solid content I. It may include.

Reactor 52, the fine particles by stirring the dross powder (P ₂₎ and water, dross is a device for decomposing a particulate powder (P ₂₎ water.

Reactor 52 may be configured as a general reactor capable of stirring gas, liquid, and solid phase materials. The reactor 52 agitates the dross fine particle powder P ₂ and water mixed at a predetermined mixing ratio to decompose the dross fine particle powder P ₂ . The mixing ratio of the dross fine particle powder (P ₂ ) and water is preferably 1: 2, but is not limited thereto.

Hereinafter, the physicochemical phenomenon that occurs when the dross fine particle powder (P ₂ ) is stirred with water will be described by dividing the properties of the materials included in the dross fine particle powder (P ₂ ).

First, among the substances contained in the dross fine particle powder (P ₂ ), the soluble solids (S) having solubility in water are dissolved in water, thereby including the soluble solids (S) as a solute and also water is a solvent. An aqueous solution Q containing as is produced. Such soluble solids (S) mainly include chloride salts contained in flux (F) such as sodium chloride (NaCl) and potassium chloride (KCl). When the mixing ratio of the dross fine particle powder P ₂ and water is 1: 2, the concentration of the chloride salt in the aqueous solution Q is about 20%.

Next, insoluble solids (I) having insolubility insoluble in water among the materials contained in the dross fine particle powder (P ₂ ) are dispersed or precipitated in the aqueous solution (Q). Insoluble solids (I) mainly include aluminum, aluminum-magnesium alloy, magnesium, aluminum oxide (Al ₂ O ₃ ), magnesium oxide (MgO), and spinel oxide (MgAl ₂ O ₄ ).

Next, among the materials included in the dross fine particle powder P ₂ , a hydrolysis reactant having a property of hydrolyzing with water is hydrolyzed by water. By this hydrolysis reaction, water decomposition solids and hydrolysis gas (G) are generated, and reaction heat is generated with this. The hydrolysis reactant mainly contains metals and metal compounds contained in spherical black dross (B ₂ ) such as aluminum (Al), magnesium (Mg), and aluminum carbide (Al ₄ C ₃ ). Here, aluminum carbide (Al ₄ C ₃ ) is not the first material of the aluminum waste can, and is a by-product generated in the process of manufacturing aluminum waste can scrap by processing the aluminum waste can.

 Looking at the hydrolysis reaction between the hydrolyzate and water, as shown in the reaction schemes 1 to 3, aluminum oxide and hydrogen are produced as the hydrolysis reaction of aluminum and water, and magnesium oxide and hydrogen as the hydrolysis reaction of magnesium and water Is produced and aluminum oxide and methane are produced as the hydrolysis reaction of aluminum carbide and water. In particular, since the hydrolysis reaction occurs violently when aluminum and the aluminum alloy is in contact with water, the temperature of the water rises to about 90 ° C. or more, so that the aforementioned hydrolysis reaction can be further promoted by such a temperature rise.

<Scheme 1>

2Al + 3H ₂ O → Al ₂ O ₃ + 3H ₂ + Heat

<Scheme 2>

Mg + H ₂ O → MgO + H ₂ + Heat

<Scheme 3>

Al ₄ C ₃ + 6H ₂ O → 2Al ₂ O ₃ + 3CH ₄ + Heat

The water-decomposed solids produced by the above-described hydrolysis reaction mainly contain insoluble solids such as aluminum oxide, magnesium oxide, aluminum oxide alloy, and carbon components, and thus are dispersed or precipitated in the aqueous solution Q. Therefore, insoluble solution (I) already contained in spherical black dross (B ₂ ) and insoluble solids produced by the water decomposition reaction are dispersed or precipitated in aqueous solution Q, respectively. For convenience of explanation, hereinafter, the insoluble solids (I) already included in the spherical black dross (B ₂ ) and the insoluble solids produced by the water decomposition reaction will be collectively referred to as insoluble solids (I). .

On the other hand, in addition to the above-described aluminum, magnesium, aluminum carbide, a small amount of hydrolysis reactants contained in the dross fine particle powder (P ₂ ) is hydrolyzed to generate various hydrolysis gases (G). The composition ratio of this hydrolysis gas (G) is shown in Table 3 below.

division Gas component (%) Hydrogen methane ethane Eten Propane Propene Hydrogen sulfide Early capture
(much) 48.14 51.55 0.020 0.009 0.009 0.012 0.0047 Terminal collection
(handful) 92.13 7.58 0.003 0.001 0.001 0.001 0.0020

As shown in Table 3, the hydrolysis gas G mainly contains methane gas (CH ₄ ) and hydrogen gas (H ₂ ). Such methane gas and hydrogen gas account for about 99% of the amount of hydrolysis gas G generated. In the initial stage of the water decomposition process, water decomposition reactions of aluminum, aluminum alloys, and aluminum carbides mainly proceed to generate hydrogen gas and methane gas. At the end of the water decomposition process after a predetermined time has elapsed since the start of the water decomposition process, the water decomposition reaction of aluminum and aluminum alloy proceeds mainly to generate hydrogen gas. The component analysis of the hydrolysis gas (G) is preferably carried out using a gas chromatograph (GC) analysis method of ASTM D1945-03, but is not limited thereto.

In addition, the measuring method of generation amount of hydrolysis gas G is not specifically limited. For example, the amount of hydrolyzed gas G can be measured by the following method. First, spherical black dross (B ₂ ) having a diameter of 2 cm to 5 cm is crushed and pulverized. Next, 0.5 cm (500 µm) passage of the crushed product of spherical black dross (B ₂ ) is obtained as a reaction sample. Thereafter, 100 g of the reaction sample and 1 L of distilled water were added to a closed glass flask having a 2 L capacity. Next, the reaction sample and distilled water are stirred at 100 rpm to 200 rpm using a reactor provided in a glass flask to decompose the reaction sample. Thereafter, the hydrolyzed gas G generated by the water decomposition of the reaction sample is collected by substituting aqueous phase from distilled water using a graduated cylinder. When 100 g of the reaction sample is water-decomposed through this test process, 8 L to 12 L of hydrolysis gas (G) can be collected.

The gas collector 54 is a device for collecting the hydrolysis gas G generated in the reactor 52.

The structure of the gas collector 54 is not specifically limited, The gas collector 54 may be comprised with the general gas collector which can collect gas from aqueous solution. The gas collector 54 collects hydrolysis gas G from the aqueous solution Q accommodated in the reactor 52 and delivers it to the gas storage unit 100.

As shown in FIG. 7, the gas collector 54 may increase the purity of a gas that is actually recyclable among the gases included in the hydrolysis gas G or separate a specific gas suitable for recycling purposes from other gases. The gas separation purifier 54a capable of separating and purifying gases contained in the hydrolysis gas G may be provided. The method for separating and purifying the gas separation purifier 54a is not particularly limited. For example, the gas separation purifier 54a may separate and purify gases included in the hydrolysis gas G through a pressure swing adsorption method. In addition, the gas separation purifier 54a may convert the methane gas separated and purified from the hydrolysis gas G to hydrogen gas by reforming it through steam methane reforming.

On the other hand, since the hydrolysis gas G is generated by a violent hydrolysis reaction, it may contain a trace amount of water. In order to solve this problem, the gas collector 54 may further include at least one of a moisture trap 54b, a moisture remover (not shown), and a desulfurizer (not shown). As illustrated in FIG. 7, the water trap 54b, the water remover, and the desulfurizer are preferably installed upstream of the gas separation purifier 54a, but are not limited thereto.

The first centrifugal separator 56 is a device for centrifuging the aqueous solution Q and the insoluble solid content I.

The first centrifuge 56 is preferably configured as a B.S.P centrifuge, but is not limited thereto. The first centrifuge 56 may include a first filter having a third reference particle size predetermined to separate the aqueous solution Q and the insoluble solid content I. The first filter is a nonwoven filter, and the third reference particle size is preferably 7 μm to 15 μm, but is not limited thereto.

The first centrifugal separator 56 centrifugally separates the aqueous solution (Q) and the insoluble solid (I) using the first filter, and then the aqueous solution (Q) is transferred to the precipitation unit (60), and the insoluble solid (I) is Deliver to insoluble solids storage unit 90.

On the other hand, the insoluble solids (I) and the aqueous solution (Q) are separated by the first centrifugal separator 56, but some of the aqueous solutions (Q) can not be separated and can be adsorbed on the surface of the insoluble solids (I). By the way, since the aqueous solution (Q) contains the soluble solids (S), there is a fear that the product prepared by recycling the insoluble solids (I) may be corroded by the chlorides contained in the soluble solids (S). In addition, when the insoluble solid (I) is dried or calcined, sodium oxide (Na ₂ O) and potassium oxide (K ₂ 0) are generated from chlorides contained in the soluble solid (S). There exists a possibility that the durability of the manufacture manufactured by recycling insoluble solid content (I) by potassium may fall.

In order to prevent this, the first centrifuge 56 washes the insoluble solids (I) in which the aqueous solution (Q) is adsorbed using distilled water so that the chlorine concentration of the insoluble solids (I) is less than or equal to a predetermined reference chlorine concentration. Distilled water used for washing solid (I) and insoluble solid (I) can be centrifuged. The washing process of insoluble solids (I) using such distilled water may be repeatedly performed until the chlorine concentration of the insoluble solids (I) is below the reference chlorine concentration. The reference chlorine concentration is preferably 300 ppm, but is not limited thereto. Here, the first centrifugal separator 56 washes the insoluble solids I by using the condensed water D transferred from the condensed water storage tank 660 of the precipitation unit 60, which will be described later, as distilled water. It is not limited.

9 is a schematic view schematically showing the configuration of the precipitation unit of FIG. 7, and FIG. 10 is a solubility graph of an aqueous chloride salt solution.

Next, the precipitation unit 60 is an apparatus for concentrating the aqueous solution Q so that the soluble solid content S is precipitated from the aqueous solution Q.

As shown in FIG. 9, the precipitation unit 60 includes a raw water supply pump 610 for pumping and supplying an aqueous solution Q delivered from the first centrifugal separator 56 of the water decomposition unit 50, and raw water. The water contained in the aqueous solution (Q) is evaporated to concentrate the aqueous solution (Q) supplied from the feed pump (610) to precipitate the soluble solids (S) from the aqueous solution (Q), respectively. A plurality of evaporation modules (620, 630, 640) and evaporation modules (620, 630,) for inducing evaporation of water, respectively, to precipitate sodium chloride (NaCl) and potassium chloride (KCl) according to different precipitation orders and precipitation times. A condenser 650 for condensing steam generated in at least one of the 640, a condensate storage tank 660 in which condensate D generated in the evaporation modules 620, 630, and 640 or the condenser 650 is stored; Selectively apply vacuum pressure to at least one of the evaporation modules 620, 630, 640. A pressure control member 670, and a soluble solid content (S) is precipitated soluble solids precipitate and the precipitate storage tank 6, which is (S ₁₎ this storage, soluble solids precipitate (S ₁₎ and separating the aqueous solution (Q) distal to A second centrifugal separator 690 may be provided.

The precipitation unit 60 includes a plurality of evaporation modules 620, 630, and 640 which are respectively provided to precipitate chloride salts included in the soluble solids S according to different precipitation orders and precipitation times. The number of installation of the evaporation module is not particularly limited. For convenience of explanation, hereinafter, the first to third evaporation modules 620 and 630 may be used to precipitate the chloride salts included in the soluble solids S according to three different deposition orders and precipitation times. For example, a case where a total of three evaporation modules are installed, such as 640, will be described for the precipitation unit 60.

The raw water supply pump 610 pumps the aqueous solution Q delivered in a state separated from the insoluble solids I from the first centrifuge 56 so as to at least one of the evaporation modules 620, 630, 640. It is provided to supply the evaporation modules 620, 630, 640. For example, as shown in FIG. 9, the raw water supply pump 610 may be supplied to the third evaporation module 640 located at the end of the energy transfer step described later among the evaporation modules 620, 630, 640. Can be prepared. To this end, the suction portion of the raw water supply pump 610 may be connected to the first centrifugal separator 56 through the flow path 611a, and the discharge portion of the raw water supply pump 610 may pass through the first evaporation module through the flow path 644a. 620 may be connected.

Meanwhile, as shown in FIG. 9, a part of the aqueous solution Q supplied to the third evaporation module 640 by the raw water supply pump 610 is the second evaporation module 630 connected to the third evaporation module 640. ) And a part of the aqueous solution Q delivered to the second evaporation module 630 may be delivered to the first evaporation module 620 connected to the second evaporation module 630. That is, the evaporation modules 620, 630, 640 are interconnected to receive the aqueous solution Q along the direction opposite to the energy transfer direction. In this case, each of the evaporation modules 620, 630, 640 is supplied with an aqueous solution Q to a predetermined level before the precipitation of the soluble solids S by heating the aqueous solution Q is started. Preferred but not limited thereto.

These evaporation modules 620, 630, 640 may be provided to be directly connected to the raw water supply pump 610, respectively. In this case, the aqueous solution supplied from the raw water supply pump 610 may be filled directly into each evaporation module 620, 630, 640 without passing through the other evaporation modules 620, 630, 640. For convenience of explanation, the evaporation modules 620 and 630 are sequentially supplied such that the aqueous solution Q supplied from the raw water supply pump 610 is sequentially delivered to the evaporation modules 620, 630 and 640 in a direction opposite to the energy transfer direction. It will be described with respect to the precipitation unit 60 on the basis of the case, 640 are interconnected.

The evaporation modules 620, 630, 640 are arranged step by step for each step of the predetermined energy transfer step. For example, if the energy transfer step is composed of a total of three steps, the first evaporation module 620 may be disposed in the first step, and the second evaporation module 630 may be disposed in the second step. In the third step, the third evaporation module 640 may be disposed.

Aqueous solution temperature In aqueous solution (Q)
Solubility (%) Solubility in Single Chloride Salt Solution (%) NaCl KCl NaCl KCl 100 ℃ 28 35 38 57 75 ℃ 29 28 38 50 50 ℃ 30 22 35 42

10 and Table 4, the solubility of sodium chloride and the solubility of potassium chloride in the aqueous solution (Q) in which soluble solids (S) is dissolved, respectively, the solubility of sodium chloride and potassium chloride in a single chloride salt solution in which only sodium chloride is dissolved, respectively. Relative to the solubility of potassium chloride in a single aqueous chloride salt solution. This change in solubility is due to the common ionic effect caused by chlorine ions (Cl ⁻⁾ which are commonly included in sodium chloride and potassium chloride, so that the solubility of sodium chloride and the solubility of potassium chloride in the aqueous solution Q are the same as described above. This is due to the reduction compared to the

10 and Table 4, the solubility of sodium chloride in the aqueous solution (Q) gradually increases as the temperature of the aqueous solution (Q) decreases, and the solubility of potassium chloride in the aqueous solution (Q) increases. It gradually increases with increasing temperature. Therefore, as the temperature of the aqueous solution Q is increased, sodium chloride is preferentially precipitated compared to potassium chloride, and as the temperature of the aqueous solution Q is lowered, potassium chloride is preferentially precipitated compared to sodium chloride.

In general, the precipitation process of the chloride salt concentrates the aqueous solution in a single evaporation module by using a high temperature steam (hereinafter referred to as 'original steam') of about 100 ° C. or more supplied from an external steam source as a heat source for heating the aqueous solution. Proceed by In this single evaporation module, when the precipitation process of soluble solids is carried out in an aqueous solution heated to a high temperature of about 100 ° C. or more using raw steam as a heat source, sodium chloride is first precipitated and then potassium chloride is subsequently precipitated. For this reason, potassium chloride begins to precipitate as a ratio only after a considerable amount of water contained in the aqueous solution is evaporated and the concentration of the chloride salt in the aqueous solution is raised to a high concentration. Then, the sodium chloride precipitate, which is mixed with the aqueous solution and is in the form of a viscous slurry, strongly adheres to the inner surface of the evaporation module and coalesces or prevents the precipitation of potassium chloride. Therefore, according to the conventional chloride salt precipitation process using a single evaporation module, there is a problem that it is difficult to smoothly recover potassium chloride having a high value compared to sodium chloride through precipitation.

However, the precipitation unit 60 includes a plurality of evaporation modules 620, 630, and 640 having different environmental conditions from each other. Here, the environmental conditions, such as the evaporation temperature of the aqueous solution (Q), the internal pressure of the evaporation modules (620, 630, 640), the solubility of each of the chloride salts in the aqueous solution (Q), the precipitation aspect of the soluble solids (S) Refers to conditions related to regulation.

According to the precipitation unit 60, through the adjustment of the environmental conditions of each of the evaporation modules (620, 630, 640), the evaporation module (620, 630) the order of precipitation, the timing of precipitation, and the precipitation pattern of other sodium chloride and potassium chloride , 640 may be individually determined.

For example, any one of the evaporation modules 620, 630, 640 may determine the environmental conditions of the evaporation modules 620, 630, 640 such that sodium chloride preferentially precipitates from a significantly earlier point than potassium chloride.

For example, the other of the evaporation modules 620, 630, 640 may determine the environmental conditions of the evaporation modules 620, 630, 640 such that sodium chloride and potassium chloride are precipitated together from about the same time.

For example, another one of the evaporation modules 620, 630, 640 may determine the environmental conditions of the evaporation modules 620, 630, 640 such that potassium chloride preferentially precipitates from a significantly earlier point than sodium chloride.

Since the precipitation unit 60 can smoothly recover high-value potassium chloride through a preferential precipitation process of potassium chloride, it is possible to minimize the amount of potassium chloride discarded without being recovered from the aqueous solution Q, and precipitation The time required for the process can be reduced.

On the other hand, when heating the aqueous solution (Q) by using the original steam (E), if the water contained in the aqueous solution (Q) is evaporated, the steam generated (hereinafter referred to as 'generating steam') is released to the atmosphere as it is, the generated steam Due to the significant heat loss in the waste heat, the energy efficiency of the precipitation process is reduced. To solve this, the evaporation modules 620, 630, 640 generate steam (E ₁ , E ₂ , E ₃ ) generated in the evaporation modules 620, 630, 640 located at specific stages of the predetermined energy transfer stage. Is preferably provided to be used as a heat source for heating the aqueous solution (Q) in the evaporation module (620, 630, 640) located after the predetermined energy transfer step compared to the specific step.

For example, the first evaporation module 620 in which the precipitation process is performed in the atmosphere having the highest temperature of the aqueous solution Q may be provided to use the original steam E as a heat source. For example, the second evaporation module 630 in which the precipitation process is performed in a lower temperature atmosphere than the first evaporation module 620 may use the generated steam E ₁ generated in the first evaporation module 620 as a heat source. Can be arranged. For example, the third evaporation module 640 in which the precipitation process is performed under a lower temperature atmosphere than the second evaporation module 630 may use the generated steam E ₂ generated in the second evaporation module 630 as a heat source. Can be arranged. Through this, the precipitation unit 60 can minimize the waste heat of the generated steam (E ₁ , E ₂ ) radiated to the outside without being recovered, it is possible to improve the energy efficiency of the precipitation process.

Hereinafter, the evaporation modules 620, 630, and 640 are provided on the basis of the case where the evaporation modules 620, 630, and 640 are provided to proceed with the precipitation process of the soluble solids S according to the aforementioned aqueous solution Q and the energy transfer method. The structure will be described.

The structure of the evaporation modules 620, 630, 640 is not particularly limited.

Each of the evaporation modules 620, 630, 640 heats the aqueous solution Q to a predetermined reference temperature, and then evaporates the water under a pressure atmosphere in which the evaporation temperature of the water contained in the aqueous solution Q is a reference temperature. It is prepared to induce precipitation of soluble solids (S). Here, the reference temperature may be individually determined for each evaporation module 620, 630, 640 according to the order of precipitation and the time of precipitation of sodium chloride and potassium chloride to be implemented using the evaporation module among the evaporation modules 620, 630, 640. have.

For example, the first evaporation module 620 may include a first reboiler 621 that heats the aqueous solution Q to a predetermined first reference temperature, and an aqueous solution Q heated to the predetermined first reference temperature. Received from the first reboiler 621, inducing the evaporation of water under an internal pressure adjusted to the evaporation temperature of the water contained in the aqueous solution (Q) to a predetermined first reference temperature, to precipitate the soluble solids (S) The first evaporator 622 and the first circulation pump 623 may be provided to circulate the aqueous solution Q to the first reboiler 621 and the first evaporator 622 in a predetermined order.

The first reference temperature is determined to induce evaporation of water under environmental conditions in which the solubility of sodium chloride in the aqueous solution (Q) is lower than the solubility of potassium chloride by a predetermined first reference value or higher, so that sodium chloride may be preferentially precipitated compared to potassium chloride. It is desirable to lose. The first reference value is not particularly limited, and the temperature of the aqueous solution Q having a solubility characteristic such that the precipitation of potassium chloride can begin as a ratio only after a considerable time has elapsed from the start of the precipitation of sodium chloride is determined by the first evaporator 622. It is preferable to set so that the evaporation temperature of the water in For example, the first reference temperature in the first reboiler 621 may be between 100 ° C. and 110 ° C., in which the solubility of sodium chloride in the aqueous solution Q is about 28% and the solubility of potassium chloride is about 35%.

For example, the second evaporation module 630 includes a second reboiler 631 for heating the aqueous solution Q to a second predetermined reference temperature, and the aqueous solution Q heated to a second predetermined reference temperature. Received from the second reboiler 631, inducing the evaporation of water under an internal pressure adjusted to the evaporation temperature of the water contained in the aqueous solution (Q) to a predetermined second reference temperature, to precipitate the soluble solids (S) The second evaporator 632 and the second circulation pump 633 may be provided to circulate the aqueous solution Q to the second reboiler 631 and the second evaporator 632 in a predetermined order.

The second reference temperature is preferably determined to induce the evaporation of water under an environmental condition in which the difference between the solubility of sodium chloride and the potassium chloride in the aqueous solution Q is equal to or less than a second predetermined reference value, so that the sodium chloride and potassium chloride can be precipitated together. Do. The second reference value is not particularly limited, and the temperature of the aqueous solution Q having a solubility characteristic in which sodium chloride and potassium chloride can be precipitated together is small because the difference between the start time of precipitation of sodium chloride and the start time of precipitation of potassium chloride is small. It is preferably set to be the evaporation temperature of the water at 632. For example, the second reference temperature may be from about 70 ° C. to about ° C. with a solubility of sodium chloride in aqueous solution Q of about 29% and potassium chloride about 28%.

For example, the third evaporation module 640 may include a third reboiler 641 for heating the aqueous solution Q to a predetermined third reference temperature, and an aqueous solution Q heated to the third predetermined reference temperature. Received from the third reboiler 641, inducing the evaporation of water under an internal pressure adjusted to the evaporation temperature of the water contained in the aqueous solution (Q) to a predetermined third reference temperature, to precipitate the soluble solids (S) The third evaporator 642 and the first circulation pump 643 for circulating the aqueous solution Q to the third reboiler 641 and the third evaporator 642 in a predetermined order may be provided.

The third reference temperature is determined to induce evaporation of water under environmental conditions in which the solubility of potassium chloride in the aqueous solution Q is lower than the solubility of sodium chloride by a predetermined third reference value or higher, so that potassium chloride can be preferentially precipitated compared to sodium chloride. It is desirable to lose. The third reference value is not particularly limited, and the temperature of the aqueous solution Q having a solubility characteristic such that the precipitation of sodium chloride can begin as a ratio only after a considerable time has elapsed from the start of the precipitation of potassium chloride is caused by the third evaporator 642. It is preferable to set so that the evaporation temperature of the water in For example, the third reference temperature may be from about 50 ° C. to 60 ° C. with a solubility of sodium chloride in the aqueous solution Q of about 30% and a solubility of potassium chloride about 22%.

Hereinafter, the first evaporation module 620 will be described based on the contents of the concentration of the aqueous solution Q and the precipitation of the soluble solids S.

The first evaporation module 620 is an evaporation module which is located in the first step of the predetermined energy transfer step and performs the precipitation process of the soluble solids S using the aqueous solution Q and the high temperature original steam E. .

The first reboiler 621 may have a shell and tube structure in which the aqueous solution Q may be heated to the first reference temperature by heat-exchanging the aqueous solution Q and the original steam E. To this end, an aqueous solution duct (not shown) may be formed at the center of the first reboiler 621, and an original steam E may be formed at an outer circumferential portion surrounding the center of the first reboiler 621. A steam duct (not shown) may be formed. As shown in FIG. 9, the first reboiler 621 may include a first inlet 621a through which the aqueous solution Q is introduced, a first outlet 621b through which the aqueous solution Q is discharged, and an external A second inlet 621c into which the original steam E supplied from the steam supply is introduced, a second outlet 621d through which the condensed water D generated by condensing the original steam E, and a second outlet 621 The condensate D discharged from 621d may have a first condensate trap 621e and the like.

The first evaporator 622 may have a hollow structure in which a space for inducing evaporation of water contained in the aqueous solution Q transferred from the first reboiler 621 is formed therein. As illustrated in FIG. 9, the first evaporator 622 includes first and second inlets 622a and 622b through which the aqueous solution Q is introduced, and a first outlet 622c through which the aqueous solution Q is discharged. ), The second outlet 622d through which the generated steam (E ₁ ) generated by evaporation of water is discharged, and the precipitate (S ₁ ) of the soluble solids (S) precipitated from the aqueous solution (Q) (hereinafter referred to as 'soluble solids precipitates'). (S ₁ ) ') may have a third discharge port 622e or the like.

The aqueous solution Q discharged from the discharge portion of the second circulation pump 633 is supplied to the first inlet 622a of the first evaporator 622 through the flow path 624a. That is, the aqueous solution Q via the second evaporator 632 is supplied to the first evaporator 622 through the second circulation pump 633.

The aqueous solution Q discharged from the first outlet 622c of the first evaporator 622 is supplied to the suction part of the first circulation pump 623 through the flow path 624b, and the first reboiler 621 The aqueous solution Q discharged from the discharge part of the first circulation pump 623 is supplied to the first inlet 621a through the flow path 624c. In addition, the original steam E is supplied to the second inlet 621c of the first reboiler 621 through the flow path 624d. Then, the aqueous solution Q supplied to the first reboiler 621 is heated by the original steam E, and the original vapor E supplied to the first reboiler 621 is cooled by the aqueous solution Q. And condensed into phase condensate (D).

In the second inlet 622b of the first evaporator 622, the aqueous solution Q discharged from the first outlet 621b of the first reboiler 621 is heated by the original steam E, and the flow path 624e. It is supplied through In addition, condensate D discharged from the second outlet 621d of the first reboiler 621 is transferred to the first condensate trap 621e of the first reboiler 621 through the flow path 624f and collected. .

When the aqueous solution Q is repeatedly circulated between the first reboiler 621 and the first evaporator 622 by the first circulation pump 623, the aqueous solution Q is heated by the original steam E. Accordingly, the temperature of the aqueous solution Q is raised to the first reference temperature. However, when the first reference temperature is about 100 ° C to 110 ° C, the first evaporator (for example, the evaporation temperature of water included in the aqueous solution Q supplied to the first evaporator 622 is about 100 ° C to 110 ° C). Preferably, the internal pressure of 622 is maintained at about +20 kPa. Since the internal pressure of about +20 kPa can be achieved using the vapor pressure of the generated steam E ₁ generated in the first evaporator 622, the first evaporator 622 has a separate pressure for adjusting the internal pressure. Installation of the adjusting member is not necessarily required.

The water contained in the aqueous solution Q supplied to the first evaporator 622 may be evaporated under an atmosphere of about 100 ° C. to 110 ° C. and about +20 Pa. Then, the aqueous solution Q may be concentrated by evaporation of water, and sodium chloride may be preferentially precipitated among the chloride salts included in the soluble solids S. Therefore, in the first evaporator 622, sodium chloride is mainly precipitated at the beginning of the precipitation process, and the precipitation amount of potassium chloride increases toward the end of the precipitation process. The soluble solid precipitate S ₁ discharged from the third outlet 622e of the first evaporator 622 may be stored in the precipitate storage tank 6 through the flow path 624g.

Hereinafter, the second evaporation module 630 will be described based on the contents of the concentration of the aqueous solution Q and the precipitation of the soluble solids S.

The second evaporation module 630 is located in the second step of the predetermined energy transfer step, except that the precipitation process of the soluble solids S is performed using the aqueous solution Q and the generated steam E1. It has a structure similar to the first evaporation module 620 described above.

The aqueous solution Q discharged from the discharge portion of the third circulation pump 643 is supplied to the first inlet 632a of the second evaporator 632 through the flow path 634a. That is, the second aqueous evaporator 632 is supplied with the aqueous solution Q via the third evaporator 642 through the third circulation pump 643.

The aqueous solution Q discharged from the first outlet 632c of the second evaporator 632 is supplied to the suction part of the second circulation pump 633 through the flow path 634b, and the second reboiler 631 of the second reboiler 631 is provided. The aqueous solution Q discharged from the discharge portion of the second circulation pump 633 is supplied to the first inlet 631a through the flow path 634c. In addition, the generated steam E ₁ generated in the first evaporator 622 is supplied to the second inlet 631c of the second reboiler 631 through the flow path 634d. In this way, the aqueous solution Q and the generated steam E ₁ supplied to the second reboiler 631 are heat-exchanged. Then, in the second reboiler 631 of an aqueous solution (Q) is generated vapor (E ₁₎ generated vapor (E ₁₎ supplying the heated, second reboiler 631 by the feed in an aqueous solution (Q) By cooling and condensing to phase change into condensate (D).

In the second inlet 632b of the second evaporator 632, the aqueous solution Q discharged from the first outlet 631b of the second reboiler 631 is heated by the generated steam E ₁ . 634e). In addition, condensate D discharged from the second outlet 631d of the second reboiler 631 is transferred to the second condensate trap 631e of the second reboiler 631 through the oil passage 634f. .

When the aqueous solution Q is repeatedly circulated between the second reboiler 631 and the second evaporator 632 by the second circulation pump 633, the generated steam E ₁ supplied from the first evaporator 622. As the aqueous solution Q is heated by), the temperature of the aqueous solution Q is raised to the second reference temperature. By the way, when the second reference temperature is about 70 ℃ to ℃, the second evaporator 632 in order for the evaporation temperature of the water contained in the aqueous solution (Q) supplied to the second evaporator 632 to be about 70 ℃ to 80 ℃ The internal pressure of) should be reduced to about -60 인 in vacuum.

To this end, the flow path 644f connected to the second outlet 641d of the third reboiler 641 is connected to the condenser 650 by the flow path 644i at the front end of the third condensate trap 641e, 644i is provided with a vacuum control valve 644j. Then, the remaining generated steam E ₂ not condensed in the steam duct among the generated steam E ₂ supplied from the second evaporator 632 to the third reboiler 641 passes through the condenser 650 through the flow path 644i. Can be delivered to. However, since the second evaporator 632 is connected by the third reboiler 641 and the flow path 644d, the internal pressure of the second evaporator 632 and the internal pressure of the steam duct of the third reboiler 641 are Can be interlocked with each other. Therefore, the internal pressure of the second evaporator 632 is selectively reduced by receiving the vacuum pressure of the pressure regulating member 670 and the negative pressure of the condenser 650 through the vacuum regulating valve 674 to be maintained in a vacuum state. Can be.

Water included in the aqueous solution Q supplied to the second evaporator 632 may be evaporated under reduced pressure in an atmosphere of about 70 ° C. to 80 ° C. and about −60 Pa. Then, the aqueous solution Q can be concentrated by evaporation under reduced pressure of water, and sodium chloride and potassium chloride contained in the soluble solids S can be precipitated together from about the same point in time. The soluble solid precipitate S ₁ discharged from the third outlet 632e of the second evaporator 632 may be stored in the precipitate storage tank 680 through the flow path 634g.

Hereinafter, the third evaporation module 640 will be described based on the contents of the concentration of the aqueous solution Q and the precipitation of the soluble solids S.

The third evaporation module 640 is located in the third step of the predetermined energy transfer step, except that the precipitation process of the soluble solids S is performed using the aqueous solution Q and the generated steam E2. It has a structure similar to the first evaporation module 620 described above.

The aqueous solution Q discharged from the discharge portion of the raw water supply pump 610 is supplied to the first inlet 642a of the third evaporator 642 through the flow path 644a. That is, the aqueous solution Q is directly supplied to the third evaporator 642 from the raw water supply pump 610.

The aqueous solution Q discharged from the first outlet 642c of the third evaporator 642 is supplied to the suction part of the third circulation pump 643 through the flow path 644b, and the third reboiler 641 The aqueous solution Q discharged from the discharge part of the 3rd circulation pump 643 is supplied to the 1 inlet port 621a through the flow path 644c. In addition, the generated steam E ₂ generated in the second evaporator 632 is supplied to the second inlet 641c of the third reboiler 641 through the flow path 644d. As such, the aqueous solution Q and the generated steam E ₂ supplied to the third reboiler 641 are heat-exchanged. Then, in the third reboiler 641 of an aqueous solution (Q) are generated steam is heated by the (E _2), the generated vapor (E ₂₎ fed to the third reboiler 641 is supplied to an aqueous solution (Q) By cooling and condensing to phase change into condensate (D).

The aqueous solution Q discharged from the first outlet 641b of the third reboiler 641 is heated in the second inlet 642b of the third evaporator 642 while being heated by the generated steam E ₂ . 644e). In addition, condensed water D discharged from the second outlet 641d of the third reboiler 641 is transferred to the fourth condensate trap 641e of the third reboiler 641 through the flow path 644f. .

When the aqueous solution Q is repeatedly circulated between the third reboiler 641 and the third evaporator 642 by the third circulation pump 643, the generated steam E ₂ supplied from the second evaporator 632. As the aqueous solution Q is heated by), the temperature of the aqueous solution Q is raised to the third reference temperature. However, when the third reference temperature is about 50 ° C to 60 ° C, the evaporator temperature of the water contained in the aqueous solution Q supplied to the third evaporator 642 is about 50 ° C to 60 ° C. The internal pressure of 642) should be reduced to about -80 kPa in vacuum.

To this end, the second outlet 642d of the third evaporator 642 is connected to the condenser 650 through the flow path 644h, and the condenser 650 is connected to the pressure regulating member 670. Through this, the internal pressure of the third evaporator 642 is reduced by the vacuum pressure applied from the pressure regulating member 670 and the negative pressure formed by condensation of the generated vapors E ₂ and E ₃ in the condenser 650. Can be maintained in a vacuum state.

Water contained in the aqueous solution Q supplied to the third evaporator 642 may be evaporated under reduced pressure in an atmosphere of about 50 ° C. to 60 ° C. and about −80 Pa. Then, the aqueous solution (Q) can be concentrated by evaporation under reduced pressure, and potassium chloride among the chloride salts contained in the soluble solids (S) can be preferentially precipitated from the aqueous solution (Q). Therefore, in the third evaporator 642, potassium chloride mainly precipitates at the beginning of the precipitation process, and the precipitation amount of sodium chloride increases toward the end of the precipitation process. The soluble solid precipitate S ₁ discharged from the third outlet 642e of the third evaporator 642 may be stored in the precipitate storage tank 680 through the flow path 644g.

The condenser 650 cools the generated steam E ₃ delivered from the third evaporator 642 and the generated steam E ₂ delivered from the second evaporator 632 via the third reboiler 641. It is prepared for condensation. The cooling source for cooling the generated steam E ₂ , E ₃ is preferably cooling water supplied from an external cooling water supply source (not shown), but is not limited thereto. As shown in FIG. 9, the condenser 650 has an inlet 651 connected to the third evaporator 642 and the third reboiler 641, respectively, through the flow paths 644h and 644i. A discharge port 653 through which the generated condensate D is discharged, a condensate trap 655 through which the condensate D discharged from the discharge port 653 is transferred and collected through the flow path 659, and a pressure regulating member 670. It may have a vent port 657 and the like connected to.

The condensate storage tank 660 is connected to the condensate traps 621e, 631e, 641e, and 655 through the flow paths 624f, 634f, 644f, 659, and 662, respectively, and the condensate traps 621e, 631e, 641e, Condensate D delivered from 655 is stored, respectively. The condensate storage tank 660 preferably supplies condensate D as distilled water for washing insoluble solids I through the flow path 664 to the first centrifuge 56, but is not limited thereto. .

The pressure regulating member 670 is provided to selectively apply a vacuum pressure to each of the second evaporator 632 and the third evaporator 642. For example, the pressure regulating member 670 may include a vacuum tank 672 in which the internal pressure is kept constant in a vacuum state, and a vacuum control valve for selectively applying the vacuum pressure of the vacuum tank 672 to the condenser 650. 674 and the like.

The vacuum tank 672 is provided to maintain a constant internal pressure in a vacuum state by a vacuum pump (not shown). The internal pressure of the vacuum tank 672 is not particularly limited. For example, the internal pressure of the vacuum tank 672 may be kept constant at about -95 kPa in a vacuum state. The vacuum tank 672 may be connected to the vent port 658 of the condenser 650 through the flow path 676.

The vacuum control valve 674 is provided in the flow path 676 so that the vacuum pressure of the vacuum tank 672 can be selectively applied to the condenser 650. Then, the vacuum pressure of the vacuum tank 672 may be selectively applied to the second evaporator 632 via the vacuum control valves 644j and 674, the condenser 650 and the third reboiler 641. The vacuum control valve 674 and the condenser 650 may be selectively applied to the third evaporator 642. Through this, the pressure regulating member 670 may maintain the internal pressure of the second evaporator 632 and the internal pressure of the third evaporator 642 so as to induce a reduced pressure evaporation of water contained in the aqueous solution Q, respectively. have.

The precipitate storage tank 680 is connected to third outlets 622e, 632e, 642e of each of the first to third evaporators 622, 632, 642 through flow paths 624g, 634g, 644g, 682. . In addition, in the flow path 682 into which the flow paths 624g, 634g, and 644g are joined, a precipitate recovery pump 684 may be installed to pump the soluble solid precipitate S ₁ toward the precipitate storage tank 680. Thus, the soluble solid precipitate S ₁ discharged from each of the first to third evaporators 622, 632, and 642 may be stored in the precipitate storage tank 680.

However, since the soluble solid precipitate (S ₁ ) is accommodated in each of the first to third evaporators 622, 632, 642 in a dispersed and precipitated state in the aqueous solution (Q), solubility in the operation of the precipitate recovery pump 684 The solid precipitate S ₁ may be discharged from each of the first to third evaporators 622, 632, and 642 in a slurry state mixed with the aqueous solution Q and stored in the precipitate storage tank 680.

On the other hand, as shown in Figure 9, the discharge portion of each of the first to third circulation pump (623, 633, 643) may be connected to the flow path 682 by each of the flow path (624h, 634h, 644k). Each of the flow paths 624h, 634h and 644k may be provided with an on / off valve for selectively opening and closing each of the flow paths 624h, 634h and 644k. Accordingly, each of the first to third circulation pumps 623, 633, and 643 may selectively deliver the aqueous solution Q to the precipitate storage tank 680 through each of the flow paths 624h, 634h, and 644k. Through this, each of the first to third circulation pumps 623, 633, 643 discharges the aqueous solution Q from each of the evaporation modules 620, 630, 640 according to the precipitation aspect of the soluble solids S, The chloride salt concentration of the aqueous solution (Q) can be maintained at a level suitable for precipitation of the soluble solids (S).

The second centrifugal separator 690 receives the soluble solid precipitate (S ₁ ) in the slurry state mixed with the aqueous solution (Q) from the precipitate storage tank 680, and receives the soluble solid precipitate (S ₁ ) and the aqueous solution (Q). It is made possible to centrifuge.

The second centrifuge 690 is preferably configured as a Contavex centrifuge, but is not limited thereto. The second centrifugal separator 690 may have a second filter having a fourth reference particle size predetermined to separate the soluble solid precipitate (S ₁ ) and the aqueous solution (Q). The second filter is a wire mesh filter, and the fourth reference particle size is preferably 0.05 mm to 0.3 mm, but is not limited thereto.

The aqueous solution Q separated from the soluble solids precipitate S ₁ by the second centrifuge 690 may include residual soluble solids S which have not yet been precipitated by the evaporation modules 620, 630, 640. have. Accordingly, the second centrifugal separator 690 may deliver the soluble solids precipitate S ₁ to the soluble solids storage unit 70, and suck the aqueous solution Q through the flow path 692 to the raw water supply pump 610. Can be passed on to wealth. The aqueous solution Q re-delivered to the raw water supply pump 610 may be mixed with the aqueous solution Q supplied from the first centrifugal separator 56 and resupplied to the evaporation modules 620, 630, and 640. have. Through this, the second centrifugal separator 690 may further increase the recovery rate of the soluble solids S through the precipitation process.

FIG. 11 is a photograph of soluble solids precipitated and dried, FIG. 12 is a SEM-EDS chart qualitatively analyzing the soluble solids shown in FIG. 11, and FIG. 13 is a chart showing the composition ratio of the soluble solids shown in FIG. 11. .

Next, the soluble solids storage unit 70 is a device for drying and storing the soluble solids precipitate (S ₁ ) received from the second centrifuge (66).

The structure of the soluble solids storage unit 70 is not particularly limited. For example, the soluble solids storage unit 70 is a soluble solids dryer 72 for drying the soluble solids precipitate S ₁ , and a dry matter of the soluble solids S dried by the soluble solids dryer 72 (hereinafter, It may include a soluble solids storage chamber 74 for storing the 'soluble solids dry (S ₂ )'.

The soluble solids dryer 72 is an apparatus for drying the soluble solids precipitate S ₁ separated from the aqueous solution Q1 by the second centrifuge 66.

The soluble solids precipitate (S ₁ ) and the aqueous solution (Q ₁ ) are separated by the second centrifuge (66), but some of the aqueous solutions (Q1) are not separated from the soluble solids precipitate (S ₁ ) and the soluble solids precipitate (S). ₁ ) can be adsorbed on the surface. For this reason, the soluble solid precipitate S ₁ separated from the aqueous solution Q1 by the second centrifuge 66 is in the slurry state by the aqueous solution Q1 adsorbed on the surface. By the way, when the soluble solids precipitate (S ₁ ) is present in the slurry state is not easy to recycle, so that the soluble solids dryer 72 is provided to solve this.

The soluble solids dryer 72 dries the soluble solids precipitate S ₁ discharged from the second centrifugal separator 66 such that the soluble solids S contain moisture of less than or equal to a predetermined reference moisture. The reference moisture is preferably about 0.3%, but is not limited thereto.

As shown in FIGS. 11 and 12, the soluble solids S ₂ dried by the soluble solids dryer 72 has a white powder form, and chlorides such as sodium chloride (NaCl) and potassium chloride (KCl). Mainly salts. The soluble solids dryer 72 thus delivers the soluble solids dry S ₂ to the soluble solids storage chamber 74.

The soluble solids storage chamber 74 is a device for storing the soluble solids dry S ₂ from which moisture has been removed by the soluble solids dryer 72.

The soluble solids storage chamber 74 may be configured as a general storage chamber capable of storing a storage object. The soluble solids storage chamber 74 receives the soluble solids dry S ₂ from the soluble solids dryer 72 and stores the soluble solids dry S ₂ in an isolated state. 12 and 13, the soluble solids dry S ₂ stored in the soluble solids storage chamber 74 mainly contains the chloride salts contained in the flux F, and thus is recycled as the flux F. It is preferable. However, the present invention is not limited thereto, and the soluble solid component (S ₂ ) may be recycled in various fields requiring mixed salts.

Next, the aluminum grain storage unit 80 is a device for storing the aluminum grains N discharged from the crushing / crushing unit 40.

The structure of the aluminum grain storage unit 80 is not specifically limited. For example, as illustrated in FIG. 7, the aluminum grain storage unit 80 may store aluminum grains N separated and discharged from the first separating member 42 and the second separating member 44. It may include a grain storage chamber 82.

Next, the insoluble solids storage unit 90 is an apparatus for drying, baking, and storing the insoluble solids I received from the first centrifuge 56.

The structure of the insoluble solids storage unit 90 is not particularly limited. For example, the insoluble solids storage unit 90 includes an insoluble solids dryer 92 for drying the insoluble solids I and an insoluble solids kiln for firing the insoluble solids I dried by the insoluble solids dryer 92. And an insoluble solids storage chamber 96 for storing the insoluble solids I fired by the insoluble solids firing furnace 94.

It is a photograph of the insoluble solid content dried.

The insoluble solids dryer 92 is a device for drying the insoluble solids I separated from the aqueous solution Q by the first centrifuge 56.

Insoluble solids (I) are separated by distilled water and the first centrifuge 56, but some of the distilled water can be adsorbed onto the surface of insoluble solids (I) without being separated from insoluble solids (I). For this reason, the insoluble solid content I discharged | emitted from the 1st centrifugal separator 56 exists in the slurry state containing about 30 to 40% of water. By the way, when the insoluble solid (I) is present in the slurry state is not easy to transport and recycle the insoluble solid (I), insoluble solids dryer 92 is provided to solve this.

The insoluble solids dryer 92 dries the insoluble solids I discharged from the first centrifugal separator 56 so that the insoluble solids I contain moisture equal to or less than a predetermined reference moisture.

The reference moisture is not particularly limited and is preferably set differently according to the purpose of recycling the insoluble solid content (I). For example, when the insoluble solid (I) is recycled to the cement raw material, the reference moisture is about 40%. For example, when the insoluble solid (I) is recycled into a brick refractory or ceramic material, the reference moisture is about 0.5%. For reference, when insoluble solids (I) are recycled to brick refractory or ceramic materials, a material calcined at about 1,200 ° C is required, and thus a relatively low standard compared to recycling insoluble solids (I) to cement raw materials. Moisture is required.

The insoluble solids drying the insoluble solids (I) drying by 92 (hereinafter referred to as "water-insoluble solid dry product (I _1)") as shown in Figure 14, dark due to the carbon components adsorbed to the surface gray Has a powder form. This insoluble solid dry matter (I ₁ ) is delivered to the insoluble solid baking (94).

15 is a photograph of the calcined insoluble solids, FIG. 16 is a SEM-EDS chart qualitatively analyzing the calcined insoluble solids shown in FIG. 15, and FIG. 17 is a composition ratio of the calcined insoluble solids shown in FIG. 15. This is a chart showing.

The insoluble solids baking furnace 94 is an apparatus for baking the insoluble solids dry matter (I ₁ ).

When the finely divided aluminum, magnesium and aluminum alloy contained in the dross fine particle powder P ₂ are water-decomposed, aluminum hydroxide, magnesium hydroxide and aluminum alloy hydrate (hereinafter, referred to as 'hydrates') may be formed. Since these hydrates are insoluble solids (I), they are separated from the aqueous solution (Q) by the first centrifuge (56) and transferred to the insoluble solids dryer (92). However, since hydrates are unstable compared to aluminum oxide, magnesium oxide and aluminum alloy oxide (hereinafter referred to as 'oxides'), insoluble solids (I) containing such hydrates are not suitable for recycling.

To solve this problem, as shown in Figure 7, the insoluble solids storage unit 90, the insoluble solid dry product (I ₁₎ to the firing process of transition to the oxide of the hydrate included in the water-insoluble solid dry product (I ₁₎ It includes an insoluble solids firing furnace (94).

The insoluble solids kiln 94 heats the insoluble solids (I ₁ ) to about 800 ° C. or more to calcinate the hydrates. The hydrates are then calcined and transferred to oxides, while at the same time the carbon component adsorbed on the surface of the insoluble solid dry matter (I ₁ ) is combusted. Accordingly, as shown in FIG. 15, the insoluble solid dry matter (I ₁ ) (hereinafter, referred to as 'insoluble solid calcined product (I ₂ )') fired by the insoluble solid firing furnace 94 is in the form of a pale yellow powder. Becomes The insoluble solids baking furnace 94 delivers such insoluble solids fired product I ₂ to the insoluble solids storage chamber 96.

On the other hand, when the insoluble solids firing furnace 94 has a structure capable of continuously performing the drying process and the firing process like the microwave firing furnace, the insoluble solids dryer 92 described above may be omitted.

Insoluble solids storage chamber 96 is a device for storing insoluble solids fired product I ₂ .

Insoluble solids storage chamber 96 may be configured as a general storage chamber capable of storing a storage object. The insoluble solids storage chamber 96 receives the insoluble solids I ₂ from the insoluble solids firing furnace 94 and stores the insoluble solids I ₂ in an isolated state from the outside. As shown in FIGS. 16 and 17, the insoluble solid calcined product (I ₂ ) mainly comprises aluminum oxide, magnesium oxide and aluminum oxide alloy, and thus, after further reactivation process, the ceramic material, the refractory material, and the cement material It is preferred to be recycled as. The further recycling step of the insoluble solid content calcined product (I ₂ ) is not particularly limited. For example, an additional recycling process of the insoluble solids (I ₂ ) may comprise a spinel manufacturing process in which aluminum oxide and magnesium oxide are calcined at about 2000 ° C. at high temperature to be transferred to spinel (MgAl ₂ O ₄ ).

Next, the gas storage unit 100 is a device for storing the hydrolyzed gas G collected by the gas collector 54.

The gas storage unit 100 may be composed of a gas storage chamber which is generally used for storing gas. As shown in FIG. 7, the gas storage unit 100 receives and stores the hydrolysis gas G from the gas collector 54.

The general dross reprocessing machine (indenter) re-processes the general black dross by injecting a heating agent flux such as saltpeter (NaNO ₃ ) into the general black dross. Water recombination of the reprocessed general black dross generates ammonia gas (NH ₃ ) and silane gas (SiH ₄ ), which are toxic to the human body, from aluminum nitride and aluminum silicide contained in the general black dross. Therefore, the gas generated by water decomposition of the reprocessed general black dross is difficult to recycle.

By the way, the hydrolysis gas G generated by processing the spherical black dross B ₂ by the black dross recycling apparatus 3 includes gases such as hydrogen, methane, ethane, ethene, propane and propene. do. These gases are easy to recycle because they do not have the same toxicity as the ammonia gas and silane gas described above as gases that can be used as energy sources. In addition, since hydrogen and methane having excellent properties as energy sources occupy most of the hydrolysis gas G, the hydrolysis gas G is very excellent in recycling value.

Such hydrolysis gas G is preferably recycled as an energy source for driving the aluminum melting and black dross recycling system 1 according to the present invention. However, the present invention is not limited thereto, and the hydrolysis gas G may be transferred to the outside by a gas transfer facility and recycled as an energy source in various industrial fields such as heating and power generation.

On the other hand, the black dross recycling apparatus 3 is preferably to process the above-described spherical black dross (B ₂ ) to be recyclable, but is not limited thereto. That is, the black dross recycling apparatus 3 may process the normal black dross formed in a different manner from the spherical black dross B ₂ so as to be recyclable.

FIG. 18 is a flowchart schematically showing a method for dissolving aluminum and recycling black dross according to another preferred embodiment of the present invention, and FIG. 19 is a detail of the step for crushing and crushing the aluminum dissolving step and spherical black dross described in FIG. 18. FIG. 20 is a flowchart for describing details of the dross powder water decomposition step and the water decomposition product recycling step described in FIG. 18.

18, the aluminum melting and black dross recycling method according to a preferred embodiment of the present invention, the step of dissolving aluminum (S 100), and spherical black dross (B ₂ ) generated when dissolving aluminum Crushing and pulverizing (S 200), spherical black dross (B ₂ ) is crushed and pulverized dross fine particle powder (P ₂ ) formed by water decomposition (S 300), dross fine particle powder (P _And treating at least one of the water degradants of ₂ ) to be recyclable (S 400).

First, as shown in FIG. 19, dissolving aluminum (S 100) may include forming a vortex (V) in the aluminum molten metal (M) (S 110) and melting the surface of the aluminum molten metal (M). Injecting the flux (F) into the vortex (V) to form a flux layer (S 120), Injecting aluminum scrap (A) into the vortex (V) to pass through the molten flux layer (S 130), Recovering the spherical black dross (B ₂ ) generated by the aluminum scrap (A) is flux-treated by the molten flux layer when the aluminum scrap (A) in the molten aluminum (M) is dissolved (S 140).

In the step (S 110) of forming the vortex V in the aluminum molten metal M, the aluminum molten metal M is agitated using the above-described vortex unit 21 that can be rotated and rotated to the aluminum molten metal M. Vortex V can be formed.

In the step S 120 of injecting the flux F into the vortex V, the flux F may be introduced into the vortex V of the molten aluminum M formed in the step S 110. Preferably, the flux (F) may include 93-97 parts by weight of a mixture of sodium chloride (NaCl) and potassium chloride (KCl) in the same parts by weight and 3-7 parts by weight of cryolite (Cryolite, Potassium Cryolite). More preferably, the flux (F) may include 47.5 parts by weight of sodium chloride (NaCl), 47.5 parts by weight of potassium chloride (KCl) and 5 parts by weight of potassium aluminum fluoride (KAlF ₄ ). When the flux F is introduced into the vortex V, a molten flux layer formed by dissolving the flux F is formed on the surface of the aluminum molten metal M, that is, a salt bath layer.

In the step of introducing the aluminum scrap (A) into the vortex (V) (S 130), the predetermined aluminum scrap (A) to the vortex (V) of the aluminum molten metal (M) to pass through the melt flux layer formed in step S 120 You can put in. Preferably, the aluminum scrap (A) may be aluminum waste can scrap (UBCs, A 3XXX series, A 5XXXX series) mainly containing aluminum, magnesium and aluminum alloy. The aluminum scrap A injected into the vortex V melt | dissolves in the aluminum molten metal M. As shown to FIG. The same time, the aluminum molten metal that is inclusion molten flux layer containing the (M), the flux (F) are trapped in the formed black dross (B _1), these black dross (B ₁₎ a vortex (V) By repeatedly lowering and floating in the molten aluminum (M) to form a spherical black dross (B ₂ ) in which the black dross (B ₁ ) is spherical.

In the step (S 140) of recovering the aluminum molten metal M and the spherical black dross B ₂ , the aluminum molten metal M in which the aluminum scrap A is dissolved is passed through the hot water outlet of the aluminum melting furnace 2 described above. Along with the discharge box, the spherical black dross B ₂ suspended on the surface of the aluminum molten metal M can be discharged from the molten aluminum M using the separation unit 27 described above.

Next, the spherical black dross (B ₂₎ the step of grinding and crushing (S 200), the method comprising crushing the spherical black dross (B ₂₎ recovered from the aluminum molten metal (M) (S 210), and aluminum Separating the granules (N) and the dross powder (P ₁ ) (S 220), pulverizing the dross powder (P ₁ ) (S 230), aluminum granules (N) and dross particulate powder ( P ₂ ) is separated (S 240).

In the step (S 210) for crushing the spherical black dross (B _2), it can be crushed using the aforementioned spherical black dross (B ₂₎ a number of times in step S 140 crusher 41

In the step of separating the aluminum grains (N) and the dross powder (P ₁ ) (S 220), the aluminum grains (N) and the dross powder (P) among the crushed products of the spherical black dross (B ₂ ) formed in step S 210. ₁ ) can be separated using the above-mentioned first separating member 42. For example, the first separating member 42 may be composed of a vibrating screen having a particle size of about 10 mm.

Pulverizing the dross powder (P ₁₎ (S 230) in, the dross powder (P ₁₎ separate from the aluminum grains (N) in step S 220 may be pulverized using a grinder (43).

In the step of separating the aluminum grains (N) and the dross particulate powder (P ₂ ) (S 240), the aluminum grains (N) and the dross particulate powder in the pulverized product of the dross powder (P ₁ ) formed in step S230. (P ₂ ) can be separated using the above-mentioned second separation member 44. For example, the second separating member 44 may be composed of a Trommel Screen having a particle size of about 0.5 mm.

On the other hand, the step of crushing and crushing the spherical black dross (B ₂ ) (200), aluminum granules separated from the dross powder (P ₁ ) and dross fine powder (P ₂ ) in step S 220 and S 240 step. (N) may further include the step (S 250). For example, in the recycling step S 250 of the aluminum grains N, the aluminum grains N may be introduced into the vortex V of the molten aluminum M described above.

Next, in the step of water-decomposing the dross fine particle powder (P ₂ ) (S 300), the dross fine particle powder (P ₂ ) re-separated from aluminum grains (N) in step S 240 using the reactor 52. It can be carried out by water decomposition. Preferably, the reactor 52 is 1: it is possible to stir the dross powder particles (P ₂₎ and water mixed in a ratio of 2, dross particles to decompose the powder (P ₂₎ water. In this way dross particles if the degradation of powder (P ₂₎ water, de los particulate powder (P ₂₎ is the water decomposition products including a hydrolysis gas (G), soluble solids content (S) and insoluble solids (I) Decompose to

Next, as shown in Figure 20, the step (S 400) of treating at least one of the water decomposition products of the dross particulate powder (P ₂ ) to be recyclable, the soluble solids (S) is produced by dissolving in water Collecting and separating the hydrolysis gas (G) from the aqueous solution (Q) thus obtained (S 410), separating the insoluble solid (I) and the aqueous solution (Q) from each other (S 420), and the hydrolysis gas (G). ) (S 430), a process of making the soluble solids (S) recyclable (S 440), and a process of making the insoluble solids (I) recyclable (S 450). do.

In the step (S 410) of collecting and separating the hydrolysis gas (G) from the aqueous solution (Q), the hydrolysis gas (G) from the aqueous solution (Q) accommodated in the reactor (52) described above using a gas collector (54). Can be captured.

As shown in FIG. 20, the step of separating the insoluble solids (I) and the aqueous solution (Q) from each other (S 420) may include centrifuging the aqueous solution (Q) and the insoluble solids (I) (S 421); The step of washing the insoluble solid (I) with distilled water (S 422), and the step of centrifuging the insoluble solid (I) and distilled water (S 423).

In the step (S 421) of centrifuging the insoluble solid (I) and the aqueous solution (Q), the first centrifugation of the insoluble solid (I) and the aqueous solution (Q) separated from the hydrolysis gas (G) in step S 410 is performed. The separator 56 can be used for centrifugation.

In the step of washing the insoluble solid (I) with distilled water (S 422), the insoluble solid (I) is washed with distilled water so that the chlorine adsorbed to the insoluble solid (I) in step S 421 is separated from the insoluble solid (I). Can be. Although the insoluble solids (I) and the aqueous solution (Q) are centrifuged in step S 421, some of the aqueous solutions (Q) may remain adsorbed on the insoluble solids (I), and such aqueous solutions (Q) may include chloride salts. Soluble solids (S) are dissolved. Therefore, insoluble solids (I) are washed with distilled water so as to remove the chloride salt adsorbed on the insoluble solids (I). In the step (S 422) of washing the insoluble solid (I) with distilled water, it is preferable to use the condensed water (D) generated in step S445 to be described later as distilled water, but is not limited thereto.

In the step (S 423) of centrifuging the insoluble solid (I) and distilled water, after step S422, the insoluble solid (I) and distilled water may be centrifuged using the first centrifuge 56 described above.

Additionally, steps S 422 and S 423 may be repeatedly performed until the concentration of the chloride salt adsorbed on the insoluble solids (I) is equal to or less than a predetermined reference concentration. The reference concentration is preferably about 300 ppm, but is not limited thereto.

As shown in FIG. 20, the treating of the hydrolyzed gas G to be recyclable (S 430) may include removing the water included in the hydrolyzed gas G (S 431), and removing moisture. Separating and purifying the hydrolyzed gas G thus obtained (S 432), and storing the separated and purified hydrolyzed gas G (S 433).

In step S431 of removing water contained in the hydrolysis gas G, the water trapr may include the water contained in the hydrolysis gas G collected by the gas collector 54 in step S 410. 54b), and may be removed using a water remover (not shown) and a desulfurizer (not shown).

In the step of separating and purifying the hydrolysis gas (G) (S 432), the purity of the gas that is actually recyclable among the hydrolysis gas (G) from which water is removed in step S 431 may be increased or the purpose of recycling in the gas decomposition gas (G) may be used. The hydrolysis gas G may be separated and purified using the gas separation purifier 54a described above so that a specific gas suitable for the separation may be separated from other gases.

In the storing of the hydrolysis gas G (S 433), the hydrolysis gas G separated and purified in step S 432 may be stored in the gas storage unit 100 described above.

As shown in FIG. 20, the step of treating the soluble solids S to be recyclable (S 440) may include water included in the aqueous solution Q using a plurality of evaporation modules 620, 630, and 640. Evaporating to precipitate the soluble solids (S) from the aqueous solution (Q) (S 441), centrifuging the soluble solids precipitate (S ₁ ) and the aqueous solution (Q) (S 442), and the soluble solids precipitate (S). ₁ ) drying the step (S 443), and storing the soluble solid dry matter (S ₂ ) (S 444) and the like.

In the step of depositing the soluble solids (S) (S 441), using the evaporation modules (620,630, 640) to evaporate the water contained in the insoluble solids (I) and the centrifuged aqueous solution (Q) in step S 421 Precipitating the soluble solids (S) from the aqueous solution (Q), but induces evaporation of water under different environmental conditions for each of the evaporation modules (620, 630, 640), different precipitation for each of the evaporation modules (620, 630, 640) Depending on the order and timing of precipitation, sodium chloride and potassium chloride contained in the soluble solids (S) may be precipitated.

In addition, in the step (S 441) of precipitation of the soluble solids (S), the evaporation modules (620, 630, 640) is separated from the insoluble solids (I) and then pumped by an aqueous water supply pump (610) (Q) ) Is supplied. For example, an aqueous solution Q separated from an insoluble solid component I may be supplied to the third evaporator 642 of the third evaporation module 640 by the raw water supply pump 610, and the third evaporator 642. A portion of the aqueous solution (Q) supplied to) may be supplied to the second evaporator 632 of the second evaporation module 630 by the third circulation pump (643), the aqueous solution supplied to the second evaporator 632 A portion of Q may be supplied to the first evaporator 622 of the first evaporation module 620 by a second circulation pump 633.

In addition, in the step (S 441) of precipitation of the soluble solids (S), the evaporation modules 620, 630, 640 directly or indirectly use the high temperature raw steam (E) supplied from an external steam source as a heat source. Soluble solid S can be precipitated by heating aqueous solution Q and evaporating water. Here, the supply of the raw steam (E) is preferably started with the evaporator (622, 632, 642) of each of the evaporation modules (620, 630, 640) the aqueous solution (Q) is filled by a predetermined level.

For example, the first reboiler 621 of the first evaporation module 620 may heat the aqueous solution by heat-exchanging the original steam E and the aqueous solution.

For example, the second reboiler 631 of the second evaporation module 630 heat-exchanges the generated steam E ₁ generated by evaporation of water in the first evaporator 622 with the aqueous solution Q to form an aqueous solution Q. Can be heated.

For example, the third reboiler 641 of the third evaporation module 640 heat-exchanges the generated steam E ₂ generated by evaporating water in the second evaporator 632 with the aqueous solution Q to form an aqueous solution Q. Can be heated.

In the step (S 441) of depositing such soluble solids (S), each of the evaporation modules 620, 630, and 640 uses the reboilers 621, 631, and 641 to form the aqueous solution Q at a predetermined reference temperature. After heating, the evaporators 622, 632 and 642 are used to induce the evaporation of water under the internal pressure of the evaporators 622, 632 and 642, which are adjusted so that the evaporation temperature of the water becomes the reference temperature, thereby precipitating the soluble solids S. Can be. The reference temperature is determined by the evaporation modules 620, 630, 640 according to the precipitation order and the timing of precipitation of sodium chloride and potassium chloride to be implemented in the evaporation modules 620, 630, 640 among the evaporation modules 620, 630, 640. Each can be individually determined.

For example, the first evaporation module 620 may use a first reboiler 621 in which the solubility of sodium chloride in the aqueous solution Q is lower than the solubility of potassium chloride by a predetermined first reference value or more. After heating the aqueous solution Q to a temperature, the first evaporator is used to induce the evaporation of water under the internal pressure of the first evaporator 622, which is adjusted so that the evaporation temperature of the water becomes the first reference temperature. At 622, sodium chloride can be preferentially precipitated from a significantly earlier point than potassium chloride.

The first reference temperature and the internal pressure of the first evaporator 622 are not particularly solved. For example, the first reference temperature may be between about 100 ° C. and 110 ° C. with a solubility of sodium chloride in aqueous solution Q of about 28% and a potassium chloride solubility of about 35%, and an internal pressure of first evaporator 622. May be about 20 kPa, which is the evaporation pressure of water from about 100 ° C to 110 ° C.

For example, the second evaporation module 630 uses the second reboiler 631 to obtain a second reference temperature at which the solubility of sodium chloride and the potassium chloride in the aqueous solution Q are lowered below a predetermined second reference value. After heating the aqueous solution Q, the second evaporator 632 is used to induce the evaporation of water under the internal pressure of the second evaporator 632, which is adjusted so that the evaporation temperature of the water becomes the second reference temperature. It can be precipitated together from about the same point of time.

For example, the second reference temperature may be about 70 ° C. to 80 ° C., with a solubility of sodium chloride in aqueous solution Q of about 29% and a potassium chloride solubility of about 28%, and an internal pressure of second evaporator 632. May be about -60 kPa, which is the evaporation pressure of water of about 70 ° C to 80 ° C.

For example, the third evaporation module 640 may use a third reboiler 641 in which the solubility of potassium chloride in the aqueous solution Q is lower than the solubility of sodium chloride by a predetermined third reference value or more. After heating the aqueous solution Q to a temperature, the third evaporator is induced by evaporating the water under the internal pressure of the third evaporator 642, which is adjusted so that the evaporation temperature of the water becomes the third reference temperature using the third evaporator 642. At (642) potassium chloride can be preferentially precipitated from a very early point in time compared to sodium chloride.

For example, the third reference temperature may be from about 50 ° C. to 60 ° C. with a solubility of sodium chloride in the aqueous solution Q of about 30% and a potassium chloride solubility of about 22%, and an internal pressure of the second evaporator 642. May be about -80 kPa which is the evaporation pressure of water of about 50 ° C to 60 ° C.

As described above, when the second reference temperature is about 70 ° C to 80 ° C and the third reference temperature is about 50 ° C to 60 ° C, in order to evaporate water in the second evaporator 632 and the third evaporator 642. The internal pressure of the second evaporator 632 and the internal pressure of the third evaporator 642 must be maintained at a lower vacuum than the atmospheric pressure. To this end, the second evaporation module 630 and the third evaporation module 640, respectively, to induce a reduced pressure evaporation of the water in a vacuum atmosphere according to the second reference temperature or the third reference temperature, the pressure regulating member 670 The internal pressure can be kept constant by the vacuum pressure selectively applied from the.

In addition, in the step (S 441) of depositing the soluble solids (S), the original steam (E) or the generated steam in the process of heat exchange with the aqueous solution (Q) of the original steam (E) or the generated steam (E ₁ , E ₂ ) Condensate D generated by cooling (E ₁ , E ₂ ) by an aqueous solution Q, and generated steam E ₂ , E ₃ discharged from the second evaporator 632 or the third evaporator 642 Condensate D generated by condensation in the condenser 650 may be stored in the condensate storage tank 660. As such, the condensed water D stored in the condensed water storage tank 660 may be delivered to the first centrifuge 56 (S 445). Then, in step S422, the insoluble solids I separated from the aqueous solution Q by the first centrifugal separator 56 may be washed using the condensed water D transferred from the condensed water storage tank 660 as distilled water. .

In the step (S 442) of centrifuging the soluble solid precipitate (S ₁ ) and the aqueous solution (Q), the soluble solid precipitate (S ₁ ) and the soluble solid precipitate (S ₁ ) precipitated from the aqueous solution (Q) in step S 441 The precipitated aqueous solution Q may be centrifuged using the second centrifuge 690 described above. The aqueous solution (Q) separated from the soluble solids precipitate (S ₁ ) as described above is evaporated so that the soluble solids (S) which remain undissolved in the aqueous solution (S) without being precipitated can be precipitated from the aqueous solution (Q). The modules 620, 630, and 640 may be retransmitted (S446). Then, in step S 441, the soluble solids S may be reprecipitated from the aqueous solution Q separated from the soluble solids precipitate S ₁ using the evaporation modules 620, 630, and 640. .

In the step (S 443) for drying the soluble solid precipitate (S _1), it can be dried using an aqueous solution of the aforementioned soluble solid content of the soluble solid precipitate (S ₁₎ separated from the (Q) dryer 72 at S 442 step . Drying the soluble solids precipitate S ₁ (S 443) is preferably performed until the soluble solids precipitate S ₁ contains 0.3% or less of water, but is not limited thereto.

In the step of storing the soluble solid dry matter S ₂ (S 444), the soluble solid dry matter S ₂ dried in step S 443 may be stored in the above-described soluble solid storage chamber 74.

As shown in Figure 20, the step of treating the insoluble solid (I) to be recyclable (S 450), the step of drying the insoluble solid (I) (S 451), and the insoluble solid dry matter (I ₁ ) And a step (S 453) of storing an insoluble solid content (I ₂ ).

In step (S 451) of drying the insoluble solid (I), the water adsorbed to the insoluble solid (I) without being separated from the insoluble solid (I) in step S420 is dried using the above-described insoluble solid dryer (92). can do. Drying the insoluble solid (I) (S 451), when recycling the insoluble solid (I) to the cement raw material is preferably performed until the insoluble solid (I ₁ ) contains 40% or less moisture. Do. In addition, the step (S 451) of drying the insoluble solid dry matter (I ₁ ), when the insoluble solid (I) is recycled to a brick refractory or ceramic material, the insoluble solid dry matter (I ₁ ) contains water of 0.5% or less. It is preferable to carry out until, but not limited to.

In the step (S 452) of calcining the insoluble solid dry product (I _1), it may be fired using an insoluble solid dry product (I ₁₎ of the above water-insoluble solid content of the baking furnace 94, dried at S 451 step. Insoluble solids (I ₁ ) may include hydroxides such as aluminum hydroxide, magnesium hydroxide and aluminum alloy hydrates having unstable properties such that these hydroxides are transferred to aluminum oxide, magnesium oxide, aluminum alloy oxides having relatively stable properties. The insoluble solid content (I ₁ ) is fired.

Storing a water-insoluble solid matter fired product (I ₂₎ (S 453) In, can be stored in a water insoluble solid content storage chamber 96 above the water-insoluble solids fired product (I ₂₎ in the firing step S 452.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art and the technical spirit of the present invention. Of course, various modifications and variations are possible within the scope of the claims.

1: aluminum melting and black dross recycling system
2: aluminum melting furnace
3: black dross recycling unit
10: heating chamber
20: melting chamber
30: flow force giving room
40: shredding / crushing unit
50: water decomposition unit
60: precipitation unit
70: soluble solids storage unit
80: Aluminum Granules Storage Unit
90: insoluble solids storage unit
100: gas storage unit
M: molten aluminum
V: Vortex
A: Aluminum Scrap
F: flux
B ₁ : Black Dross
B ₂ : spherical black dross
P ₁ : dross powder
P ₂ : dross particulate powder
N: Aluminum Grain
S: Soluble Solids
I: insoluble solids
Q: Aqueous Solution
G: hydrolysis gas
E: original steam
E ₁ , E _2, E ₃ : Generated Steam
D: condensate

Claims (12)

(a) crushing and pulverizing black dross generated by dissolving the aluminum scrap in the molten aluminum by fluxing the aluminum scrap by a flux containing sodium chloride and potassium chloride, and dividing it into aluminum grains and dross particulate powder;
(b) hydrolyzing the dross particulate powder with water to produce an aqueous solution in which soluble solids containing sodium chloride and potassium chloride are dissolved; And
(c) evaporating the water contained in the aqueous solution using a plurality of evaporation modules, respectively, to precipitate the soluble solids from the aqueous solution, inducing the evaporation of the water under different environmental conditions for each of the evaporation modules; And depositing the sodium chloride and the potassium chloride according to different precipitation order and precipitation timing for each. The method of claim 1,
In the step (c), each of the evaporation module, after heating the aqueous solution to a predetermined reference temperature using a reboiler, the internal pressure of the evaporator is adjusted so that the evaporation temperature of the water to the reference temperature using an evaporator Black dross recycling method, characterized in that the evaporation of the water under induction to precipitate the soluble solids. The method of claim 2,
The reference temperature is black dross recycling method, characterized in that for each of the evaporation module of the evaporation module, the evaporation module, the evaporation module, the evaporation module, the evaporation module according to the deposition order and the timing of deposition of each of the evaporation module. The method of claim 3,
In the step (c), the evaporation module of at least one of the evaporation module, the solubility of the sodium chloride in the aqueous solution using the reboiler is lowered by a predetermined first reference value or more compared to the solubility of the potassium chloride. After heating the aqueous solution to a first reference temperature, the evaporator is used to induce the evaporation of the water under an internal pressure of the evaporator which is adjusted such that the evaporation temperature of the water becomes the first reference temperature, thereby bringing the sodium chloride into the potassium chloride. Black dross recycling method, characterized in that to precipitate preferentially. The method of claim 3,
In the step (c), the evaporation module of at least one of the evaporation module, the difference between the solubility of the sodium chloride and the solubility of the potassium chloride in the aqueous solution by using the reboiler is lower than a second predetermined reference value or less After heating the aqueous solution to a second reference temperature, the evaporator induces the evaporation of the water under an internal pressure of the evaporator, in which the evaporation temperature of the water is adjusted to the second reference temperature, thereby reducing the sodium chloride and the potassium chloride. Black dross recycling method characterized in that to precipitate together. The method of claim 3,
In the step (c), the evaporation module of at least one of the evaporation module, so that the solubility of the potassium chloride in the aqueous solution is lowered below a predetermined third reference value compared to the solubility of the sodium chloride using the reboiler. Heating the aqueous solution to a third reference temperature, and then using the evaporator to preferentially precipitate the potassium chloride over the sodium chloride under an internal pressure of the evaporator adjusted such that the evaporation temperature of the water becomes the third reference temperature. A black dross recycling method characterized by the above-mentioned. The method of claim 2,
In step (c), the evaporation module of at least one of the evaporation modules is a vacuum pressure selectively applied from the pressure regulating member so as to induce a reduced pressure evaporation of the water in a vacuum atmosphere according to the predetermined reference temperature. The internal pressure of the evaporator is maintained in a vacuum state by the black dross recycling method. The method of claim 1,
(d) further centrifuging the soluble solid precipitate precipitated from the aqueous solution and the aqueous solution mixed with the soluble solid precipitate;
In the step (c), reusing the evaporation modules to re-precipitate the soluble solids from the aqueous solution separated from the soluble solids precipitate in the step (d). The method of claim 8,
(e) drying the soluble solids precipitate separated from the aqueous solution in step (d) and storing the black dross. The method of claim 1,
In the step (c), the evaporation module of at least one of the evaporation module, heat the aqueous solution by heat-exchanging the aqueous solution and the original steam supplied from an external steam source,
In the step (c), at least another one of the evaporation module, the evaporation module generated by the water evaporated in the at least one evaporation module or any other evaporation module of the evaporation module And recycling the generated steam and the aqueous solution by heating the aqueous solution to heat the aqueous solution. The method of claim 10,
(f) further comprising centrifuging the insoluble solids dispersed and precipitated in the aqueous solution and the aqueous solution,
In the step (c), using the evaporation module, the black dross recycling method characterized in that to precipitate the soluble solids from the aqueous solution separated from the insoluble solids. The method of claim 11,
(g) separated from the aqueous solution in step (f) by using the condensed water produced by cooling the original steam or the generated steam by the aqueous solution or the condensed water produced by condensing the original steam or the generated steam by a condenser. The black dross recycling method further comprises the step of washing the insoluble solids.

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