WO2020111848A1 - System and method for melting aluminum and recycling black dross - Google Patents

Abstract

The present invention pertains to a method for recycling black dross, the method comprising: (a) a step in which black dross, generated when aluminum scraps are flux-treated with a flux containing sodium chloride and potassium chloride while being melted in molten aluminum, is crushed and pulverized into aluminum particles and dross particulate powder; (b) a step in which the dross particulate powder is hydrolyzed with water to produce an aqueous solution in which soluble solids including sodium chloride and potassium chloride are dissolved; and (c) a step for precipitating the soluble solids from the aqueous solution by using a plurality of evaporation modules to evaporate the water contained in the aqueous solution, wherein the evaporation modules each induce the evaporation of the water under different environmental conditions so that the sodium chloride and the potassium chloride are precipitated in a different precipitation order and at a different precipitation time by each of the evaporation modules.

Description

Aluminum melting and black dross recycling system and method

The present invention relates to an aluminum melting and black dross recycling system and method for performing an aluminum scrap melting process and a black dross recycling process.

Many aluminum parts used in automobiles, home appliances, and construction materials are manufactured using aluminum casting devices. It is an aluminum melting furnace that supplies aluminum molten metal to such an aluminum casting apparatus. The aluminum melting furnace is a device that melts aluminum scrap molded to a certain size with high heat.

Conventional aluminum melting furnace, a heating chamber having a burner for heating the aluminum molten metal, a molten metal stirring chamber provided with a molten metal pump for pumping the aluminum molten metal discharged from the heating chamber, and aluminum compression to the aluminum molten metal discharged from the molten metal stirring chamber It includes a charging chamber for charging a chip mass.

Here, the aluminum compaction chip mass is also referred to as an aluminum mass, and is a compaction of a number of aluminum chips that are frequently generated during production or processing of aluminum products. However, the aluminum compaction chip mass contains a large number of voids in the process of compressing the aluminum chip. Therefore, in the conventional aluminum melting furnace, heat is not easily transferred to the center of the aluminum compressed chip mass inputted into the aluminum molten metal, so that the melting efficiency decreases, and the aluminum compression chamber mass is floated to the surface of the aluminum molten metal and is brought into contact with the atmosphere to produce aluminum oxide. There was a problem.

In order to solve the above-mentioned problems, a conventional aluminum melting furnace is pumped in a molten metal stirring chamber, and then the aluminum compressed chip mass is introduced into the aluminum molten metal transferred to the charging chamber, but in this case, aluminum is still used due to the low specific gravity of the aluminum compressed chip mass. Dissolution proceeds while the compressed chip mass is suspended in the aluminum melt. Therefore, the conventional aluminum melting furnace has a problem that the melting efficiency is low and the production rate of aluminum oxide is high, so that the real rate of pure aluminum is lowered.

Meanwhile, since aluminum is a highly oxidizing metal, aluminum oxide is generated in the process of dissolving aluminum in an aluminum melt. When the amount of aluminum oxide generated increases, the recovery rate of aluminum decreases. In addition, in general, a paint or other inclusion is interposed in the aluminum mass that is introduced into the aluminum melt. When this inclusion increases, the purity of the aluminum decreases.

In order to solve the problems caused by these aluminum oxides and inclusions, a flux (F) that prevents oxidation of aluminum and can also trap inclusions is introduced into the aluminum melt. The dross generated by the flux treatment of the molten aluminum is referred to as a black dross.

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

The present invention is to solve the above-mentioned problems, and an object thereof is to provide an aluminum melting and black dross recycling system having an improved structure so as to increase the melting efficiency of aluminum scrap.

Further, the present invention has an object to provide an aluminum dissolution and black dross recycling system with an improved structure to reduce the amount of aluminum oxide produced.

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

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

Furthermore, an object of the present invention is to provide an improved aluminum dissolving and black dross recycling system so that chloride salts contained in the flux for flux treatment of aluminum scrap can be smoothly recovered from the black dross.

Black dross recycling method according to a preferred embodiment of the present invention for solving the above problems, (a) when dissolving aluminum scrap in an aluminum melt, the aluminum scrap is flux treated with a flux containing sodium chloride and potassium chloride Crushing and grinding the generated black dross into aluminum particles 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 to deposit 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. And depositing the sodium chloride and the potassium chloride according to different precipitation order and precipitation time for each module.

Preferably, in the step (c), each of the evaporation modules, after heating the aqueous solution to a predetermined reference temperature using a reboiler, the evaporator adjusted so that the evaporation temperature of the water to the reference temperature using an evaporator The 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 precipitation order and the precipitation time of the sodium chloride and the potassium chloride to be implemented in the evaporation module among the evaporation modules.

Preferably, in step (c), at least one evaporation module among the evaporation modules uses a reboiler, solubility of the sodium chloride in the aqueous solution is greater than a predetermined first reference value compared to the solubility of the potassium chloride. After heating the aqueous solution to a first reference temperature that is lowered by as much as possible, the evaporator is used to induce evaporation of the water under the internal pressure of the evaporator adjusted so that the evaporation temperature of the water becomes the first reference temperature. Precipitation is preferred over the potassium chloride.

In step (c), at least one of the evaporation modules of the evaporation module, the difference between the solubility of the sodium chloride and the solubility of the potassium chloride in the aqueous solution using the reboiler is lower than a predetermined second reference value After heating the aqueous solution to a second reference temperature, the evaporator is used to induce evaporation of the water under the internal pressure of the evaporator adjusted so that the evaporation temperature of the water becomes the second reference temperature, so that the sodium chloride and the potassium chloride are Precipitate together.

Preferably, in step (c), at least one of the evaporation modules 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 the 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 adjusted so that the evaporation temperature of the water becomes the third reference temperature using the evaporator. Precipitate.

In step (c), at least one evaporation module among the evaporation modules may be vacuum pressure selectively applied from a pressure regulating member to induce reduced pressure evaporation of the water under a vacuum atmosphere according to the predetermined reference temperature. The internal pressure of the evaporator is thereby maintained in a vacuum.

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

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

Preferably, in step (c), at least one of the evaporation modules, the evaporation module heats the aqueous solution by exchanging the original steam and the aqueous solution supplied from an external steam source, and in the step (c) , At least one evaporation module among the evaporation modules is generated by evaporation of the water in the at least one evaporation module, or generated by evaporation of the water in another evaporation module among the evaporation modules. The aqueous solution is heated by exchanging the generated steam with the aqueous solution to heat 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, and in the step (c), using the evaporation modules, from the aqueous solution separated from the insoluble solids The soluble solid content is precipitated.

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

Black dross recycling apparatus according to another preferred embodiment of the present invention for solving the above-described problem, when the aluminum scrap is dissolved in an aluminum melt, the aluminum scrap is generated by flux treatment with a flux containing sodium chloride and potassium chloride In the black dross recycling apparatus for recycling dross, hydrolysis reaction of dross particulate powder, which is a crushed product of the black dross, with water, produces an aqueous solution in which soluble solids containing the sodium chloride and the potassium chloride are dissolved. Water decomposition unit; And evaporating the water contained in the aqueous solution to deposit the soluble solids from the aqueous solution, respectively, and inducing the evaporation of the water under different environmental conditions, thereby depositing the sodium chloride and the potassium chloride according to different precipitation sequences and precipitation times. Precipitation includes a precipitation unit having a plurality of evaporation modules.

Preferably, at least one evaporation module of the plurality of evaporation modules, the solubility of the potassium chloride in the aqueous solution induces the evaporation of the water under a temperature condition that is lower than the solubility of the sodium chloride by a predetermined reference value or more, The potassium chloride is preferentially precipitated over the sodium chloride.

Preferably, the at least one evaporation module uses the generated steam generated by evaporation of the water in at least one of the evaporation modules as the heat source for heating the aqueous solution in the evaporation module.

Preferably, the at least one evaporation module induces reduced pressure evaporation of the water under a vacuum atmosphere so that the water can be evaporated under the temperature condition.

Preferably, at least one evaporation module among the plurality of evaporation modules induces the evaporation of the water under a temperature condition in which the solubility of the sodium chloride in the aqueous solution is lower than a predetermined reference value compared to the solubility of the potassium chloride, The sodium chloride is preferentially precipitated over the potassium chloride.

Preferably, each of the evaporation modules, a reboiler for heating the aqueous solution to a predetermined reference temperature; And an evaporator that receives the aqueous solution heated to the reference temperature from the reboiler and induces the evaporation of the water under an internal pressure adjusted so that the evaporation temperature of the water becomes the predetermined reference temperature, thereby depositing the soluble solids. do.

Preferably, each of the evaporation modules further includes a circulation pump for circulating the aqueous solution in the predetermined order in the reboiler and the evaporator.

Preferably, the precipitation unit further includes a centrifugal separator for centrifuging the soluble solids precipitate and the aqueous solution, where the soluble solids are precipitated and crystallized.

Preferably, the precipitating unit stores the soluble solid content precipitate discharged in a slurry state mixed with the aqueous solution from the evaporator of at least one of the evaporation modules, and the soluble solid content precipitate in the slurry state is added to the centrifuge. It further comprises a deposit storage tank to transfer.

Preferably, the centrifuge redistributes the aqueous solution separated from the soluble solids precipitate to the evaporation modules.

Preferably, it further comprises a soluble solids storage unit for drying and storing the soluble solids precipitate separated from the aqueous solution by the winshim separator.

Preferably, the reboiler of at least one of the evaporation modules heats the aqueous solution using the original steam supplied from an external steam source as a heat source, and at least another evaporation module of the evaporation modules The reboiler of the steam generated by the evaporation of the water in the evaporator of the at least one evaporation module or the steam generated by the evaporation of the water in the evaporator of another evaporation module among the evaporation modules The aqueous solution is heated by using as a heat source.

Preferably, the reference temperature and the internal pressure for each of the evaporation modules are individually determined according to the type of chloride salt to be preferentially precipitated in the evaporation module among the sodium chloride and the potassium chloride.

Preferably, the reference temperature in the evaporation module to preferentially precipitate the potassium chloride among the evaporation modules is a temperature at which the solubility of the potassium chloride in the aqueous solution is lowered by a predetermined reference value or more than the solubility of the sodium chloride. Is set to be the evaporation temperature of the water, and the internal pressure in the evaporation module to preferentially precipitate the potassium chloride among the evaporation modules is adjusted such that the water contained in the aqueous solution is evaporated at the evaporation temperature.

Preferably, the reference temperature in the evaporation module to preferentially precipitate the sodium chloride among the evaporation modules is a temperature at which the solubility of the sodium chloride in the aqueous solution is lowered by a predetermined reference value or more than the solubility of the potassium chloride. Is set to be the evaporation temperature of the water, and the internal pressure in the evaporation module to preferentially precipitate the sodium chloride among the evaporation modules is adjusted such that the water contained in the aqueous solution is evaporated at the evaporation temperature.

Preferably, the precipitation unit, by adjusting the internal pressure of the evaporator of at least one of the evaporation module of the evaporation module, a pressure control member capable of inducing the reduced pressure evaporation of the water under a vacuum atmosphere according to the reference temperature in the evaporator It is further provided.

Preferably, the pressure regulating member includes: a vacuum tank in which a predetermined vacuum pressure is maintained; And at least one vacuum regulating valves that regulate the internal pressure by selectively applying the vacuum pressure to the evaporator of the at least one evaporation module.

Preferably, the precipitation unit further includes a raw water supply pump that supplies the aqueous solution generated in the water decomposition unit to the evaporator of at least one of the evaporation modules.

Preferably, the evaporator of the at least one evaporation module, the at least one evaporation so that the aqueous solution supplied from the raw water supply pump can be delivered to the evaporator of at least one evaporation module of the evaporation modules. It is connected to the evaporator of the module.

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

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

Second, the present invention can improve economic efficiency by recycling materials of economic value included in the spherical black dross.

Third, the present invention recycles materials contained in the spherical black dross into aluminum particles, soluble solids, insoluble solids, and hydrolysis gas according to their characteristics, and discards them without being recycled among the materials included in the spherical black dross. It is possible to further improve the economic efficiency by minimizing the substances.

Fourth, the present invention, by using a plurality of evaporation modules individually, by precipitating the chloride salts contained in the soluble solids from the aqueous solution produced by the hydrolysis reaction of black dross in a variety of ways, by adding a high value of potassium chloride, other fluxes The constituent chloride salts can be recycled more effectively.

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

Figure 2 is a schematic diagram schematically showing the aluminum melting furnace of Figure 1;

3 is a cross-sectional view of the dissolution chamber and the flow force imparting chamber of FIG. 2;

4 is a schematic view showing an aspect in which spherical black dross is formed in the melting chamber of FIG. 2.

Figure 5 is a photograph of a spherical black dross formed in the melting chamber of Figure 2;

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

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

8 is a photograph of the atomized dross powder.

9 is a schematic view schematically showing the configuration of the precipitation unit of FIG. 7.

10 is a solubility graph of an aqueous chloride salt solution.

Figure 11 is a photograph of the soluble solids precipitated and dried.

12 is a SEM-EDS chart of qualitative analysis of the soluble solids shown in FIG. 11.

13 is a chart showing the composition ratio of soluble solids shown in FIG. 11;

14 is a photograph of insoluble solids that have been dried.

Fig. 15 is a photograph of insoluble solids subjected to calcination.

16 is a SEM-EDS chart of qualitative analysis of the insoluble solids subjected to the calcination treatment shown in FIG. 15.

Fig. 17 is a chart showing the composition ratio of the insoluble solid content subjected to the calcination treatment shown in Fig. 15;

18 is a flow chart schematically showing a method for recycling aluminum melting and black dross according to another preferred embodiment of the present invention.

19 is a flow chart for explaining the details of the aluminum dissolving step and the crushing and grinding of 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. 18.

The terms or words used in the present specification and claims should not be interpreted as being limited to ordinary or lexical meanings, and the inventor can appropriately define the concept of terms in order to best describe his or her invention. Based on the principle that it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention. Therefore, the embodiments shown in the embodiments and the drawings described in this specification are only the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that there may be equivalents and variations.

In the drawings, the size of each component or a specific part constituting the component is exaggerated, omitted, or schematically illustrated for convenience and clarity. Therefore, the size of each component does not entirely reflect the actual size. When it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the 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 flux-treated aluminum molten metal; And a black dross recycling apparatus 3 for recycling black dross formed by inclusions contained in the aluminum molten metal trapped in the flux when the aluminum scrap is dissolved in the aluminum molten metal. The aluminum melting and black dross recycling system 1 dissolves aluminum scrap in a flux-treated aluminum molten metal so as to secure an aluminum molten metal for manufacturing an aluminum casting, and recycles the components contained in the black dross. It is to handle the black dross so that it can be done.

Hereinafter, for convenience of description, the aluminum melting furnace 2 is first described, 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 the aluminum molten metal M is heated, and a melting chamber in which aluminum scrap A and flux F are respectively introduced into the aluminum molten metal M. (20) and a flow force imparting chamber (20) that provides a flow force to the aluminum molten metal (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 fluid force imparting chamber 30 are respectively provided in a state independent of the 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 aluminum molten metal M to a predetermined temperature.

The heating chamber 10 communicates with the second flow passage 29 of the melting chamber 20 to be described later, and receives the aluminum molten metal M from the melting chamber 20. The heating chamber 10 is formed of a closed structure blocked from the outside, except for portions connected to the first flow passage 16 and the second flow passage 29, which will be described later, so that heat loss can be minimized.

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 aluminum molten metal M accommodated in the heating chamber 10 to the flow force imparting chamber 30.

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

As shown in FIG. 2, the heating unit 12 may be a burner installed on walls partitioning the heating chamber 10. The heating temperature of the aluminum molten metal M is not particularly 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, and The molten metal M can be heated to a predetermined heating temperature.

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

The hot water outlet 14 may be connected to an aluminum casting apparatus for manufacturing an aluminum casting, or may be connected to a molten metal transport container for transferring the aluminum molten metal M. An opening/closing valve 18 for selectively opening and closing the outlet 14 may be installed in the outlet 14.

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

2, the first flow passage 16 is formed through a wall partitioning the heating chamber 10 and the flow force imparting chamber 30, and the aluminum molten metal M has a first flow passage ( 16) is introduced into the flow force imparting chamber (30).

3 is a cross-sectional view of the dissolution chamber and the flow force imparting chamber shown in FIG. 2, and is a view showing an aspect in which spherical black dross is formed in the dissolution chamber of FIG. 2 shown in FIG. 4, and the dissolution of FIG. 2 shown in FIG. This is a picture of a spherical black dross formed in a thread.

The melting chamber 20 is a space for introducing the flux F and the aluminum scrap A into the molten aluminum M.

The melting chamber 20 communicates with the third flow passage 34 of the flow force imparting chamber 30 to be described later, and receives the aluminum molten metal M from the flow force imparting chamber 30. The melting chamber 20 is formed of an open structure in which at least a portion of the upper surface is opened so that the flux (F) and the aluminum scrap (A) can be introduced into the aluminum molten metal (M), and is relatively smaller than the heating chamber (10). It has a volume. That is, the melting chamber 20 is formed of an open structure so that the aluminum scrap (A) can be dissolved into the melting chamber 20 to perform the melting operation, and the heating chamber 10 is relatively reduced to reduce heat loss. It has a small volume.

2 and 3, the melting chamber 20, the vortex unit 21 to generate a vortex (V) orbiting and descending to the molten aluminum (M), and the flux (F) vortex (V) Flux supply unit (23) to be put in, raw material supply unit (25) to put aluminum scrap (A) into vortex (V), and aluminum molten metal (M) accommodated in melting chamber (20) in heating chamber (10) It includes a second flow passage 29 for delivery to the.

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

The vortex unit 21 is installed in the melting chamber 20 such that at least a portion is immersed in the aluminum molten metal M. When the flow of the aluminum molten metal M flowing into the melting chamber 20 through the vortex V generated by the vortex unit 21 and the third flow passage 34 directly faces the aluminum molten metal M ) Flow may be hindered. In order to prevent this, as shown in Figure 2, the vortex unit 21 is preferably installed on one side of the melting chamber 20 so as not to be located in line with the third flow passage 34, but is limited to this It is not.

As shown in FIG. 3, the vortex unit 21 has a rotating shaft having a lower end immersed in the aluminum molten metal M and an upper end extending outward of the aluminum molten metal M and axially coupled with a drive motor (not shown) ( 21a), and a stirring impeller 21b axially coupled to the lower end of the rotating shaft 21a. As shown in FIG. 3, when the driving motor is driven, the stirring impeller 21b rotates around the rotating shaft 21a in the aluminum molten metal M accommodated in the melting chamber 20 by rotating about the rotating shaft 21a. A descending vortex (V) is produced.

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

The flux (F) is a mixed salt having a specific gravity smaller than that of aluminum, and is formed of a material having high affinity with inclusions. As shown in FIG. 3, the flux supply unit 23 injects this 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 then spread evenly over the melting chamber (20). However, the present invention is not limited thereto, and the flux supply unit 23 may also input the flux F into a portion other than the vortex V.

The timing for introducing the flux F is not particularly limited. For example, in the flux supply unit 23, the flux F may be pre-injected into the vortex V before the raw material supply unit 25 injects the aluminum scrap A into the vortex V. Then, the flux F is immersed and dissolved in the molten aluminum M while turning and descending by the vortex V. However, since the flux (F) has a smaller specific gravity than 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 on the surface of the aluminum molten metal (M), That is, a salt bath layer is formed. The molten flux layer can prevent the aluminum melt (M) and the aluminum script (A) introduced into the aluminum melt (M) from contacting oxygen in the atmosphere, thereby reducing the amount of aluminum oxide.

The 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 equal parts by weight, and 3-7 parts by weight of cryolite (Cryolite, Potassium Cryolite). More preferably, the flux (F) may include ₄ 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 the aluminum scrap (A) is started by the raw material supply unit 25 to be described later, the flux supply unit 23 simultaneously or simultaneously with the raw material supply unit 25 or at this time the flux (F) vortex (V) Can be put in. That is, even after the introduction of the aluminum scrap (A), the flux (F) is continuously or intermittently supplied in accordance with the supply trend of the aluminum scrap (A).

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

The raw material supply unit 25 is a device for introducing the aluminum scrap A supplied from an external raw material supply source (not shown) into the aluminum molten metal M accommodated in the melting chamber 20.

As illustrated 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 and dissolved in the aluminum molten metal (M) while turning and descending by the vortex (V), so that the contact between the aluminum scrap (A) immersed in the aluminum molten metal (M) and the atmosphere is more By effectively blocking, the amount of aluminum oxide generated can be further reduced.

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

When 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 the aluminum scrap (A) has a diameter of 5 cm or less. The type of the aluminum scrap (A) is not particularly limited. For example, the aluminum scrap (A) may be aluminum waste can scrap (UBCs, A 3XXX series, A 5XXXX series) mainly containing aluminum, magnesium, and aluminum alloy. Table 1 shows the chemical composition of the aluminum waste can scrap.

part	Al alloy	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 (介在物, Inclusions) of the aluminum scrap (A), when the aluminum scrap (A) is charged and dissolved in the molten aluminum (M), has a property of agglomeration with molten aluminum. However, the flux layer for the flux, that is, the flux (F), weakens the cohesive force of the inclusions and molten aluminum to dissociate the inclusions and molten aluminum, and selectively captures the molten aluminum and the dissociated inclusions to form black dross (B ₁ ). do. The black dross (B ₁ ), the volume is increased in the above-described formation process, has a specific gravity lower than that of molten aluminum, and thereby rises to the surface of the molten aluminum (M).

In addition, as shown in Figures 3 and 4, the black dross (B ₁ ), the vortex (V) is lowered by turning, and when it reaches the lower end of the vortex (V) is released from the vortex (V), and then After rising to the surface of the aluminum molten metal (M), it is again joined to the vortex (V) by the suction force of the vortex (V). Therefore, the black dross (B ₁ ) is combined with other black dross (B ₁ ) produced on the surface of the aluminum molten metal (M) through this process. As illustrated in FIG. 5, when this process is repeated, a spherical black dross B ₂ in which a plurality of black drosses B ₁ are aggregated into a spherical shape is formed. That is, the vortex unit 21 repeatedly descends and floats the black dross (B ₁ ) through the vortex (V), so that a plurality of black dross (B ₁ ) are spherically shaped black dross (B) ₂ ). The chemical composition of the spherical black dross (B ₂ ) is not particularly 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 of sodium chloride (NaCl), 47.5 parts by weight of potassium chloride (KCl) and potassium aluminum fluoride ( KAlF ₄ ) When it contains 5 parts by weight. The chemical composition of the spherical black dross (B ₂ ) is shown in Table 2.

Composition chemicals	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 ), because the black dross (B ₁ ) is gradually formed while repeatedly descending and floating the aluminum molten metal (M), the general black dross formed once without such a descent and injury process Compared to this, the inclusion removal performance is excellent. For this reason, when forming a spherical black dross (B ₂ ), the aluminum content in the dross can be reduced compared to the case of forming a normal black dross. That is, a general black dross, for example, a conventional black dross formed by fluxing a white dross in a conventional aluminum can dissolution process has an aluminum content of about 50% or more, while a spherical black dross (B ₂ ) is about It has an aluminum content of 10% or less. Therefore, by forming the spherical black dross (B ₂ ), the recovery rate of dissolution of pure aluminum can be improved. In addition, by forming the spherical black block dross (B2), the dross reprocessing process to recover the aluminum trapped in the dross by reprocessing the dross using the exothermic flux and the reprocessing indenter can be omitted, so such dross The cost of reprocessing can be reduced.

The second flow passage 29 is a passage for transferring the aluminum molten metal 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 through a wall partitioning the melting chamber 20 and the heating chamber 10, and the aluminum molten metal M is the second flow passage 29. It flows into the heating chamber 10 through.

Next, the flow force imparting chamber 30 is a space for applying a flow force to the aluminum molten metal 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 and receives the aluminum molten metal M from the heating chamber 10.

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

2 and 3, the fluid force imparting chamber 30 accelerates the aluminum molten metal M, and the acceleration unit 32 that provides the fluid force to the aluminum molten metal M, and the fluid force is applied It includes a third flow passage 34 for transferring the molten aluminum (M) to the melting chamber (20).

The acceleration unit 32 is installed in the flow force imparting chamber 30 so that at least a portion is immersed in the aluminum molten metal M. For example, as shown in FIG. 3, the acceleration unit 32 receives the driving force from a driving motor (undocing) provided outside the fluid force imparting chamber 30, to the fluid force imparting chamber 30. It may be a molten metal pump capable of circulating the accommodated aluminum molten metal (M).

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

2 and 3, the third flow passage 34 penetrates through the lower portion of the wall partitioning the flow force imparting chamber 30 and the melting chamber 20 so as to face the impeller of the acceleration unit 32. Is formed, the aluminum molten metal (M) flows into the melting chamber 20 through the third flow passage 34.

On the other hand, in the present specification, it has been described that the flow force imparting chamber 30 provided with the acceleration unit 32 between the heating chamber 10 and the melting chamber 20 is not limited thereto. That is, the vortex unit 20 of the melting chamber 20 forms a vortex (V) to raise and lower the aluminum molten metal (M), and at the same time, the flow force for circulating the aluminum melting furnace (2) to the aluminum molten metal (M). Since it can be applied, the flow force imparting chamber 30 and the acceleration unit 32 provided therein can be omitted.

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

When a large number of spherical black dross (B ₂ ) is concentrated in the vortex (V), the descending 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. 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 separating the spherical black dross (B ₂ ) grown by a predetermined reference diameter from the vortex (V).

The reference diameter of the spherical black dross (B ₂ ) 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 by weight of potassium aluminum fluoride (KAlF ₄ ) In the case of containing a part, the reference diameter of the spherical black dross (B ₂ ) is 2 cm to 5 cm.

In order to detach 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 be further included.

As shown in FIG. 3, the separating unit 27 has a shape capable of pulling the spherical black dross B ₂ floating 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 separation plate 27a. Here, the driving 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 is pulled away from the vortex V using the separation plate 27a to be separated from the vortex V. Can be. Thus, a spherical black dross (B ₂₎ can be prevented from dropping because of the formation efficiency of the dense doemeuro spherical black dross (B _2). Here, the separation unit 27 may also perform the function of discharging the spherical black dross B ₂ from the aluminum molten metal M and discharging it to the outside.

Meanwhile, 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 aluminum molten metal M accommodated in the melting chamber 20 ) Is covered with a spherical black dross (B ₂ ) deviating from the vortex (V). Therefore, the aluminum molten metal (M) accommodated in the melting chamber 20 is blocked from the atmosphere by the spherical black dross (B ₂ ) covering it, and the spherical black dross (B ₂ ) is the aluminum molten metal accommodated in the melting chamber (20). It has a warming 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 accommodated in the melting chamber is generally about 700° C. or less, but in the aluminum melting furnace 2, the temperature of the aluminum molten metal M accommodated in the melting chamber 20 is about 730° C. or more. Can be elevated. For this reason, the aluminum melting furnace 2 can further improve the melting efficiency of the aluminum scrap A compared to the conventional aluminum melting furnace.

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

When the aluminum scrap (A) is melted using the above-described aluminum melting furnace 2, a spherical black dross B _{2 in which} black dross B ₁ is aggregated into a spherical shape is formed. Although the spherical black dross (B ₂ ) is relatively low compared to the normal black dross, it contains not only a certain proportion of aluminum, but also a certain proportion of materials of economic value such as aluminum oxide and flux (F). . Therefore, when such a spherical black dross (B ₂ ) is disposed of through a method such as landfill without reprocessing, materials contained in the spherical black dross (B ₂ ) cannot be recycled, and economical efficiency is reduced. There is a possibility that environmental pollution is caused by the spherical black dross (B ₂ ).

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 crushes and crushes the spherical black dross (B ₂ ) into aluminum grains (N) and dross particulate powder (P ₂ )/ The pulverization unit 40 and the water decomposition unit 50 that decomposes the dross particulate powder (P ₂ ) into water and decomposes it into soluble solid content (S), insoluble solid content (I), and hydrolysis gas (G). , The precipitation unit 60 for concentrating the aqueous solution (Q) in which the soluble solid content (S) is dissolved so that the soluble solid content (S) precipitates, and storing the soluble solid content for drying and storing the precipitate (S ₁ ) of the soluble solid content (S) The unit 70, an aluminum granule storage unit 80 for storing aluminum granules N, an insoluble solid content storage unit 90 for drying and storing insoluble solids I, and hydrolysis gas G It may include a gas storage unit 100 for storing.

First, the crushing/crushing unit 40 is a device 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 separating member 44 for separating the pulverized by pulverized dross particulate powder (P ₂ ).

The crusher 41 is a device for crushing a spherical black dross (B ₂ ) and dividing it into aluminum particles (N) and dross powder (P ₁ ).

Among the aluminum particles and the aluminum alloy particles included in the spherical black dross (B ₂ ), aluminum particles and aluminum alloy particles having a relatively large particle size are aggregated due to heat generated when crushing the spherical black dross (B ₂ ). It becomes an aluminum granule (Aluminum Granule) and an aluminum alloy granule (Aluminum Alloy Granule). Further, among the aluminum particles and the aluminum alloy particles included in the spherical black dross (B ₂ ), aluminum particles and aluminum alloy particles having a relatively small particle size become aluminum powder and aluminum alloy powder without being aggregated. Hereinafter, for convenience of description, the aluminum grains N and the aluminum alloy grains will be collectively referred to as aluminum grains N.

The crusher 41, using the properties of the above-described aluminum particles, crushes the spherical black dross (B ₂ ) supplied from the aluminum melting furnace 2 and divides it into aluminum particles (N) and dross powder (P ₁ ). do. The dross powder (P ₁ ), among the materials of the spherical black dross (B ₂ ), includes the remaining materials, except for the aluminum particles having a relatively large particle size, in powder form.

The first separating member 42 is a member for separating the aluminum grains N and the dross powder P ₁ among 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 configured as 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 separation member 42 separates the aluminum particles N and the dross powder P ₁ , the aluminum particles N are transferred to the aluminum storage unit 80 and also the dross powder P ₁ ) Is transferred to the grinder 43.

The pulverizer 43 is a _device for pulverizing dross powder P ₁ and dividing it into aluminum granules N and dross particulate powder P ₂ .

Among the materials contained in the dross powder (P ₁ ), insoluble solids (I), such as aluminum oxide and magnesium oxide, are preferably atomized to facilitate recycling. Therefore, the pulverizer 43 for pulverizing the dross powder P ₁ is provided.

However, while crushing the dross powder (P ₁ ) using the grinder 43, some aluminum particles contained in the dross powder (P ₁ ) are aggregated to generate aluminum particles (N). Therefore, the pulverizer 43 is pulverized dross powder P ₁ received from the first separating member 42 and is divided into aluminum particles N and pulverized into fine-grained dross particulate powder P ₂ .

The second separating member 44 is a member for separating the aluminum granules N and the dross particulate 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 separation 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, after separating the aluminum granules (N) and dross particulate powder (P ₂ ) received from the grinder 43, the aluminum granules (N) is transferred to the aluminum granule storage unit 80 And also the dross particulate powder (P ₂ ) is delivered to the water decomposition unit 50.

8 is a photograph of dross particulate powder.

Next, the water decomposition unit 50 is a device for decomposing water of the dross particulate powder P ₂ received from the second separation member 44.

As shown in FIG. 8, the dross particulate powder (P ₂ ) is a dark gray powder, including substances having various physicochemical properties such as flux (F), aluminum, aluminum-magnesium alloy, magnesium, and oxide. It has a 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 a water decomposition unit 50 capable of decomposing water.

The water decomposition unit 50, the dross particulate powder (P ₂ ) is decomposed into water and water to decompose into soluble solids (S), insoluble solids (I) and hydrolysis gas (G), dross particulate powder (P) ₂ ) a reactor 52 for stirring with water, a gas collector 54 for collecting hydrolysis gas (G), and a first centrifuge 56 for centrifuging the aqueous solution (Q) and insoluble solids (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.

The reactor 52 may be configured as a general reactor capable of stirring substances in a gas, liquid, or solid phase. The reactor 52 is stirred in the dross particulate powder (P ₂ ) and water mixed at a predetermined mixing ratio to decompose the dross particulate powder (P ₂ ) into water. The mixing ratio of the dross particulate powder (P ₂ ) and water is preferably 1:2, but is not limited thereto.

Hereinafter, the physicochemical phenomenon that occurs when the dross particulate powder (P ₂ ) is stirred with water will be described by dividing the properties of the substances contained in the dross particulate powder (P ₂ ) by properties.

First, among the substances contained in the dross particulate powder (P ₂ ), the soluble solid component (S) having solubility in water is soluble in water, and thus contains the soluble solid component (S) as a solute and also water An aqueous solution (Q) containing as is produced. The soluble solid content (S) mainly includes chloride salts contained in flux (F), such as sodium chloride (NaCl) and potassium chloride (KCl). When the mixing ratio of the dross particulate powder (P ₂ ) and water is 1:1, the concentration of the chloride salt in the aqueous solution (Q) is about 20%.

Next, among the substances contained in the dross particulate powder (P ₂ ), an insoluble solid (I) having an insolubility that does not dissolve in water is dispersed or precipitated in an aqueous solution (Q). The insoluble solid content (I) mainly includes aluminum, aluminum-magnesium alloy, magnesium, aluminum oxide (Al ₂ O ₃ ), magnesium oxide (MgO), and spinel oxide (MgAl ₂ O ₄ ).

Next, among the substances contained in the dross particulate powder (P ₂ ), a hydrolysis reaction product having a property of hydrolyzing with water is hydrolyzed by water. The hydrolysis reaction generates water decomposition solids and hydrolysis gas (G), and consequently, heat of reaction is generated. The hydrolysis reaction product mainly includes 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 cans, and is a by-product produced in the process of manufacturing the aluminum waste can scrap by processing the aluminum waste cans.

Looking at the hydrolysis reaction of the hydrolysis reaction product and water, as shown in Reaction Schemes 1 to 3, aluminum oxide and hydrogen are generated as the aluminum and water are hydrolyzed, and magnesium oxide and hydrogen as the magnesium and water are hydrolyzed. Is produced, and aluminum oxide and methane are generated as the aluminum carbide and water are hydrolyzed. In particular, when the aluminum or aluminum alloy is in contact with water, the hydrolysis reaction occurs violently and the temperature of the water rises to about 90° C. or higher, so the above-described hydrolysis reaction can be further promoted by this temperature increase.

<Scheme 1>

2Al + 3H ₂ O → Al ₂ O ₃ + 3H ₂ + Heat

<Reaction 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 solid content produced by the hydrolysis reaction described above mainly contains insoluble solid content such as aluminum oxide, magnesium oxide, aluminum oxide alloy, and carbon components, and thus is dispersed or precipitated in an aqueous solution (Q). Therefore, the insoluble solid content (I) already contained in the spherical black dross (B ₂ ) and the insoluble solid content generated by the water decomposition reaction are dispersed or precipitated in the aqueous solution Q, respectively. For convenience of description, hereinafter, the insoluble solid content (I) already included in the spherical black dross (B ₂ ) and the insoluble solid content generated by the water decomposition reaction will be collectively referred to as an insoluble solid content (I). .

Meanwhile, in addition to the above-described aluminum, magnesium, and aluminum carbide, a small amount of hydrolysis reactants contained in the dross particulate powder (P ₂ ) is hydrolyzed, thereby generating various hydrolysis gases (G). The composition ratio of the hydrolysis gas (G) is shown in Table 3 below.

division	Gas composition (%)
	Hydrogen	methane	ethane	Ethen	Propane	Propene	Hydrogen sulfide
Initial capture (large)	48.14	51.55	0.020	0.009	0.009	0.012	0.0047
Terminal capture (small amount)	92.13	7.58	0.003	0.001	0.001	0.001	0.0020

As shown in Table 3, the hydrolysis gas (G) mainly includes methane gas (CH ₄ ) and hydrogen gas (H ₂ ). The methane gas and the hydrogen gas account for about 99% of the generated amount of the hydrolysis gas (G). In the early stage of the water decomposition process, the water decomposition reaction of aluminum, aluminum alloy, and aluminum carbide mainly proceeds, and hydrogen gas and methane gas are mainly generated. At the end of the water decomposition process, a predetermined time has elapsed since the start of the water decomposition process, the water decomposition reaction of aluminum and aluminum alloy mainly proceeds, and hydrogen gas is mainly generated. The component analysis of the hydrolysis gas (G) is preferably carried out using the GC (Gas Chromatography) analysis method of ASTM D1945-03, but is not limited thereto.

Meanwhile, the method for measuring the amount of hydrolysis gas (G) generated is not particularly limited. For example, the generation amount of hydrolysis 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 ground. Next, a 0.5 cm (500 μm) passage in the pulverized product of the spherical black dross (B ₂ ) is obtained as a reaction sample. Thereafter, 100 g of the reaction sample and 1 L of distilled water are introduced into a sealed glass-made flask having a 2 L capacity. Next, the reaction sample and distilled water are stirred at 100 rpm to 200 rpm using a reactor installed in a glass flask to decompose the reaction sample by water. Subsequently, the hydrolysis gas (G) generated by water decomposition of the reaction sample is collected by distillation of water from distilled water using a graduated cylinder. Water decomposition of 100 g of the reaction sample through such a test process can capture 8L to 12L of hydrolysis gas (G).

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 particularly limited, and the gas collector 54 may be configured as a general gas collector capable of collecting gas from an aqueous solution. The gas collector 54 collects the 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 can increase the purity of the gas that is actually recyclable among the gases contained in the hydrolysis gas G, or separate a specific gas suitable for the purpose of recycling from other gases. Thus, a 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 the gas contained in the hydrolysis gas G through a pressure swing adsorption method. In addition, the gas separation purifier 54a may convert methane gas purified from the hydrolysis gas G through hydrogen methane reforming to convert it to hydrogen gas.

On the other hand, since the hydrolysis gas (G) is generated by violent hydrolysis reaction, it may contain a trace amount of moisture. To solve this, the gas collector 54 may further include at least one of a moisture trap 54b, a moisture eliminator (not shown) and a desulfurizer (not shown). As shown in FIG. 7, such a water trap 54b, a water remover, and a 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 an aqueous solution (Q) and an insoluble solid content (I).

The first centrifuge 56 is preferably composed of a B.S.P centrifuge, but is not limited thereto. The first centrifugal separator 56 may include a first filter having a predetermined third reference particle size to separate the aqueous solution (Q) and insoluble solids (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, after centrifuging the aqueous solution (Q) and the insoluble solid content (I) using a first filter, the aqueous solution (Q) is transferred to the precipitation unit 60 and the insoluble solid content (I) is Transfer to the insoluble solids storage unit 90.

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

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

9 is a schematic diagram 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 a device 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 Evaporated water contained in the aqueous solution (Q) so that the aqueous solution (Q) supplied from the feed pump (610) is concentrated to precipitate soluble solids (S) from the aqueous solution (Q), respectively, but contained in the aqueous solution under different environmental conditions A plurality of evaporation modules (620, 630, 640) and evaporation modules (620, 630,) for inducing evaporation of water to precipitate sodium chloride (NaCl) and potassium chloride (KCl) according to different deposition order and precipitation timing, respectively A condenser 650 for condensing steam generated in at least one of 640, a condensate storage tank 660 in which condensate D generated in the evaporation modules 620, 630, 640 or condenser 650 is stored, A pressure regulating member 670 for selectively applying vacuum pressure to at least one of the evaporation modules 620, 630, and 640, and a precipitate storage tank in which soluble solids precipitate S _{1 from} which soluble solids S are deposited is stored. (6) and a second centrifuge 690 for centrifuging the soluble solid precipitate (S ₁ ) and the aqueous solution (Q).

The precipitation unit 60 includes a plurality of evaporation modules 620, 630, and 640, which are respectively provided so that chloride salts contained in the soluble solid component S can be precipitated according to different precipitation orders and precipitation times. The number of evaporation modules installed is not particularly limited. For convenience of description, hereinafter, the first to third evaporation modules 620 and 630 allow the chloride salts contained in the soluble solids (S) to be precipitated according to three different precipitation methods and precipitation times, respectively. , 640) The precipitation unit 60 will be described as an example in which a total of three evaporation modules are installed.

The raw water supply pump 610 pumps an aqueous solution (Q) delivered in a separated state from the insoluble solids (I) from the first centrifugal separator (56) to at least one of the evaporation modules (620, 630, 640) It is provided to supply to the evaporation modules (620, 630, 640). For example, as shown in FIG. 9, the raw water supply pump 610 is supplied to the third evaporation module 640 located in the last step of the energy transfer step, which will be described later, among the evaporation modules 620, 630, and 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 be connected to the first evaporation module through the flow path 644a ( 620).

Meanwhile, as illustrated 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 connected to the third evaporation module 640 and the second evaporation module 630 ), 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, and 640 are interconnected to receive the aqueous solution Q along the opposite direction of the energy transfer direction. In this case, to each of the evaporation modules 620, 630, and 640, the aqueous solution Q is supplied to a predetermined water level before the precipitation operation of the soluble solids S through heating of the aqueous solution Q begins. Preferably, but not limited to.

Each of these evaporation modules 620, 630, and 640 may be provided to be directly connected to the raw water supply pump 610. In this case, the aqueous solution supplied from the raw water supply pump 610 can be directly charged to each evaporation module 620, 630, 640 without going through other evaporation modules 620, 630, 640. For convenience of explanation, the evaporation modules 620, 630 such that the aqueous solution Q supplied from the raw water supply pump 610 is sequentially delivered to the evaporation modules 620, 630, 640 in a direction opposite to the energy transfer direction. , 640) The precipitation unit 60 will be described on the basis of the interconnection.

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

Aqueous solution temperature	Solubility in aqueous solution (Q) (%)		Solubility in aqueous 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 an aqueous solution (Q) in which the soluble solids (S) are dissolved are, respectively, the solubility of sodium chloride and only potassium chloride in a single chloride salt aqueous solution in which only sodium chloride is dissolved. Solubility of potassium chloride in aqueous single chloride salt solution is relatively low. This change in solubility is due to the common ionic effect caused by chlorine ions (Cl ^-) commonly contained in sodium chloride and potassium chloride, solubility of sodium chloride in aqueous solution (Q) and solubility of potassium chloride are respectively the single chloride salt solution described above. It is due to the decrease compared to the field.

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) of the aqueous solution (Q) The temperature increases gradually. Therefore, as the temperature of the aqueous solution Q increases, sodium chloride preferentially precipitates compared to potassium chloride, and as the temperature of the aqueous solution Q decreases, potassium chloride precipitates preferentially compared to sodium chloride.

In general, the precipitation process of chloride salt is concentrated in a single evaporation module, using high temperature steam (hereinafter referred to as'primary vapor') of about 100° C. or higher supplied from an external steam source as a heat source for heating the aqueous solution. To proceed. In such a single evaporation module, when the precipitation process of a soluble solid content is performed on an aqueous solution heated to a high temperature of about 100° C. or higher by using the original steam as a heat source, sodium chloride is preferentially precipitated, and then potassium chloride is subsequently precipitated. Due to this, a significant amount of water contained in the aqueous solution is evaporated, and the potassium chloride starts to precipitate as a ratio only after 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 has a viscous slurry, strongly adheres to the inner surface of the evaporation module and adheres, or interferes with 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 added value compared to sodium chloride through precipitation.

However, the precipitation unit 60 is provided with a plurality of evaporation modules (620, 630, 640) having different environmental conditions from each other. Here, as the environmental conditions, 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), such as the precipitation of soluble solids (S) Refers to conditions related to regulation.

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

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

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

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

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

On the other hand, when heating the aqueous solution (Q) using the original steam (E), when the water contained in the aqueous solution (Q) evaporates and releases the steam (hereinafter referred to as'generated steam') to the atmosphere, the generated steam The energy efficiency of the precipitation process is reduced due to the significant heat loss in the waste heat. To solve this, the evaporation modules 620, 630, 640 generate steam (E ₁ , E ₂ , E ₃ ) generated by the evaporation modules 620, 630, 640 located in a specific step of a predetermined energy transfer step. It is preferable that the evaporation modules (620, 630, 640) located at a later stage of a predetermined energy transfer stage are used as a heat source for heating the aqueous solution (Q) compared to the specific stage.

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

Hereinafter, based on the case where the evaporation modules 620, 630, and 640 are provided to enable the precipitation process of the soluble solid content (S) according to the above-described aqueous solution (Q) and energy delivery 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), after heating the aqueous solution (Q) to a predetermined reference temperature, the evaporation of water under a pressure atmosphere controlled so that the evaporation temperature of the water contained in the aqueous solution (Q) becomes the reference temperature Induction, it is provided to precipitate the soluble solid (S). Here, the reference temperature may be individually determined for each of the evaporation modules (620, 630, 640) according to the precipitation order and the precipitation time 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 includes a first reboiler 621 that heats the aqueous solution Q to a first predetermined reference temperature, and an aqueous solution Q heated to a first predetermined reference temperature. It is delivered from the first reboiler 621 and induces the evaporation of water under an internal pressure controlled so that the evaporation temperature of the water contained in the aqueous solution (Q) becomes a predetermined first reference temperature, thereby precipitating soluble solids (S) 1 may have an evaporator 622 and a first circulation pump 623 for circulating 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 where the solubility of sodium chloride in aqueous solution (Q) is lower than the solubility of potassium chloride by a predetermined first reference value or higher, so that sodium chloride can 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 precipitation of potassium chloride can be started as a ratio only after a considerable time has elapsed from the start time of the precipitation of sodium chloride is the first evaporator 622 It is preferably set to be the evaporation temperature of water in ). For example, the first reference temperature in the first reboiler 621 may be 100°C to 110°C in which the solubility of sodium chloride in 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 which heats the aqueous solution Q to a predetermined second reference temperature, and an aqueous solution Q heated to a predetermined second reference temperature. The agent which is delivered from the second reboiler 631 and induces the evaporation of water under an internal pressure controlled so that the evaporation temperature of the water contained in the aqueous solution Q becomes a predetermined second reference temperature, thereby precipitating soluble solids (S) 2 may have an evaporator 632 and a second circulation pump 633 for circulating 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 so that the difference between the solubility of sodium chloride and the solubility of potassium chloride in the aqueous solution (Q) is less than a predetermined second reference value to induce evaporation of water and precipitate sodium chloride and potassium chloride together. Do. The second reference value is not particularly limited, and the difference between the start time of the precipitation of sodium chloride and the start time of the potassium chloride is small, so that the temperature of the aqueous solution (Q) having solubility characteristics that sodium chloride and potassium chloride can be precipitated together is the second evaporator It is preferred to be set to be the evaporation temperature of water at (632). For example, the second reference temperature may be from about 70° C. to about ℃ solubility of sodium chloride in aqueous solution (Q) is about 29% and solubility of potassium chloride is about 28%.

For example, the third evaporation module 640 includes a third reboiler 641 for heating the aqueous solution Q to a predetermined third reference temperature, and an aqueous solution Q heated to a predetermined third reference temperature. The agent which is delivered from the third reboiler 641 and induces evaporation of water under an internal pressure controlled so that the evaporation temperature of the water contained in the aqueous solution Q becomes a predetermined third reference temperature, thereby precipitating soluble solids (S) 3 may have an evaporator 642, a first circulation pump 643 for circulating the aqueous solution Q to the third reboiler 641 and the third evaporator 642 in a predetermined order.

The third reference temperature is determined so that the solubility of potassium chloride in aqueous solution (Q) is lower than the solubility of sodium chloride by an evaporation of water under environmental conditions that is lower than the predetermined third reference value, so that potassium chloride can be preferentially precipitated over 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 precipitation of sodium chloride can be started as a ratio only after a considerable time has elapsed from the start time of the precipitation of potassium chloride is the third evaporator 642 It is preferably set to be the evaporation temperature of water in ). For example, the third reference temperature may be about 50° C. to 60° C., in which the solubility of sodium chloride in aqueous solution (Q) is about 30% and the solubility of potassium chloride is about 22%.

Hereinafter, the first evaporation module 620 will be described with focus on the content of the aqueous solution Q and precipitation of the soluble solid content S.

The first evaporation module 620 is an evaporation module that is located in the first step of a predetermined energy transfer step and proceeds with a precipitation process of soluble solids (S) using an aqueous solution (Q) and high temperature original steam (E). .

The first reboiler 621 may have a shell and tube structure capable of heating the aqueous solution Q to a first reference temperature by exchanging heat between the aqueous solution Q and the original steam E. To this end, an aqueous solution duct (not shown) through which the aqueous solution Q is passed may be formed in the center of the first reboiler 621, and the original vapor (E) may be provided in the outer circumference surrounding the center of the first reboiler 621. ) May be formed through a steam duct (not shown). As shown in FIG. 9, the first reboiler 621 includes a first inlet 621a through which an aqueous solution Q is introduced, a first outlet 621b through which an aqueous solution Q is discharged, and external The second inlet 621c through which the original steam E supplied from the steam source flows in, the second outlet 621d through which the condensate D generated by condensing the original steam E is discharged, and the second outlet ( It may have a first condensate trap (621e) and the like is collected from the condensate (D) discharged from 621d.

The first evaporator 622 may have a hollow structure in which a space for evaporating water contained in the aqueous solution Q transferred from the first reboiler 621 is formed. As illustrated in FIG. 9, the first evaporator 622 includes first and second inlets 622a and 622b into which the aqueous solution Q is introduced, and a first outlet 622c from which the aqueous solution Q is discharged. ), a second outlet (622d) through which the generated vapor (E ₁ ) generated by evaporation of water is discharged, and a precipitate (S ₁ ) of soluble solids (S) precipitated from an aqueous solution (Q) (hereinafter,'soluble solids precipitates) (Referred to as (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 first evaporator 622 is supplied with an aqueous solution Q via the second evaporator 632 through the second circulation pump 633.

An 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 portion of the first circulation pump 623 is supplied to the 1 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 steam E supplied to the first reboiler 621 is cooled by the aqueous solution Q And condensed to phase change into condensed water (D).

In the second inlet 622b of the first evaporator 622, an aqueous solution Q discharged from the first outlet 621b of the first reboiler 621 in a state heated by the original steam E is the flow path 624e ). In addition, the 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 vapor E Accordingly, the temperature of the aqueous solution Q is raised to the first reference temperature. By the way, when the first reference temperature is about 100 ℃ to 110 ℃, the evaporator temperature of the water contained in the aqueous solution (Q) supplied to the first evaporator 622 is about 100 ℃ to 110 ℃ first evaporator ( It is preferred that the internal pressure of 622) is maintained at about +20 kPa. Since the internal pressure of about +20 ㎪ can be achieved by 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. The installation of the adjustment member is not essential.

Water contained in the aqueous solution (Q) supplied to the first evaporator 622 may be evaporated under an atmosphere of about 100 ℃ to 110 ℃ and about +20 ㎪. Then, the aqueous solution (Q) may be concentrated by evaporation of water, and sodium chloride may be preferentially precipitated among chloride salts contained in the soluble solid (S). Therefore, in the first evaporator 622, sodium chloride is mainly precipitated at the beginning of the precipitation process, and the amount of potassium chloride increases as the end of the precipitation process progresses. The soluble solids 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 with reference to the contents of concentration of the aqueous solution Q and precipitation of the soluble solid content 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 an aqueous solution (Q) and generated steam (E1) , 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 evaporator 632 is supplied with an aqueous solution Q via the third evaporator 642 through the third circulation pump 643.

The inlet of the second circulation pump 633 is supplied with an aqueous solution Q discharged from the first outlet 632c of the second evaporator 632 through the flow path 634b, and the second reboiler 631 The aqueous solution Q discharged from the discharge portion of the second circulation pump 633 is supplied to the 1 inlet 631a through the flow path 634c. In addition, the generated vapor 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. As described above, the aqueous solution Q supplied to the second reboiler 631 and the generated steam E ₁ 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) Cooling and condensation by the phase change to condensed water (D).

The second inlet 632b of the second evaporator 632 has an aqueous solution Q discharged from the first outlet 631b of the second reboiler 631 in a state heated by the generated steam E ₁ . 634e). In addition, condensate D discharged from the second outlet 631d of the second reboiler 631 is collected and collected in the second condensate trap 631e of the second reboiler 631 through the flow path 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 increases to the second reference temperature. By the way, when the second reference temperature is about 70 ℃ to ℃, the evaporation temperature of the water contained in the aqueous solution (Q) supplied to the second evaporator 632 is about 70 ℃ to 80 ℃ second evaporator (632 ) The internal pressure of the vacuum should be reduced to about -60 ㎪.

To this end, the flow passage 644f connected to the second outlet 641d of the third reboiler 641 is connected to the condenser 650 by the flow passage 644i at the front end of the third condensate trap 641e, and the flow passage ( 644i) is provided with a vacuum control valve 644j. Then, among the generated steam E ₂ supplied from the second evaporator 632 to the third reboiler 641, the remaining generated steam E _{2 that} is not condensed in the steam duct is condenser 650 through the flow path 644i. Can be passed on. 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 It 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, thereby maintaining the vacuum state. Can be.

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

Hereinafter, the third evaporation module 640 will be described with focus on the content of the aqueous solution Q and precipitation of the soluble solid content 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) 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 passage 644a. That is, the third evaporator 642 is supplied with an aqueous solution Q directly from the raw water supply pump 610.

An 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 passage 644b, and the third reboiler 641 The aqueous solution Q discharged from the discharge portion of the third circulation pump 643 is supplied to the 1 inlet 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 described above, the aqueous solution Q supplied to the third reboiler 641 and the generated steam E ₂ 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) Cooling and condensation by the phase change to condensed water (D).

In the second inlet 642b of the third evaporator 642, an aqueous solution Q discharged from the first outlet 641b of the third reboiler 641 in a state heated by the generated steam E ₂ is a flow path ( 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 and is collected through the flow passage 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 increases to a third reference temperature. By the way, when the third reference temperature is about 50 ℃ to 60 ℃, the evaporation temperature of the water contained in the aqueous solution (Q) supplied to the third evaporator 642 to be about 50 ℃ to 60 ℃ third evaporator ( 642) the internal pressure 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 generated by condensation of the vapors E ₂ and E ₃ in the condenser 650, It can be kept in a vacuum.

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

The condenser 650 is the generated vapor transmission from the third evaporator (642) (E ₃₎ and the third the generated vapor (E ₂₎ transmitted from the reboiler a second evaporator 632 via 641, respectively, cooled and It is prepared to condense. 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 includes an inlet 651 connected to the third evaporator 642 and the third reboiler 641 through flow paths 644h and 644i, respectively. The generated condensate (D) is discharged outlet (653), the condensate (D) discharged from the outlet (653) is transferred through the flow path (659) and trapped condensate trap (655), and the pressure regulating member (670) It may have a vent hole 657 and the like.

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

The pressure regulating member 670 is provided to selectively apply vacuum pressure to each of the second evaporator 632 and the third evaporator 642. For example, the pressure regulating member 670 includes a vacuum tank 672 where the internal pressure is kept constant in a vacuum state, and a vacuum regulating valve that selectively applies the vacuum pressure of the vacuum tank 672 to the condenser 650. (674).

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 installed in the flow path 676 to selectively apply the vacuum pressure of the vacuum tank 672 to the condenser 650. Then, the vacuum pressure of the vacuum tank 672 can be selectively applied to the second evaporator 632 via the vacuum control valves 644j, 674, the condenser 650, and the third reboiler 641, , It may be selectively applied to the third evaporator 642 via the vacuum control valve 674 and the condenser 650. Through this, the pressure regulating member 670, the internal pressure of the second evaporator 632 and the internal pressure of the third evaporator 642, respectively, are included in the aqueous solution (Q) can be kept constant so that reduced pressure evaporation of water is induced. have.

The precipitate storage tank 680 is connected to the third outlets 622e, 632e, and 642e of each of the first to third evaporators 622, 632, and 642 through the flow paths 624g, 634g, 644g, and 682. . Further, a flow path 682 in which the flow paths 624g, 634g, and 644g are joined may be provided with a precipitate recovery pump 684 capable of pumping the soluble solids precipitate S ₁ toward the precipitate storage tank 680. Thus, the soluble solids 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, the soluble solids precipitate (S ₁ ) is dispersed and precipitated in the aqueous solution (Q) and is accommodated in each of the first to third evaporators 622, 632, and 642, so that it is available when the precipitate recovery pump 684 is operated. The solid content 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.

Meanwhile, as illustrated in FIG. 9, the discharge portions of the first to third circulation pumps 623, 633, and 643 may be connected to the flow path 682 by each of the flow paths 624h, 634h, and 644k. Each of the flow paths 624h, 634h, and 644k may be provided with an on-off valve that can selectively open and close 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 the flow paths 624h, 634h, and 644k, respectively. Through this, each of the first to third circulation pumps 623, 633, and 643 discharges the aqueous solution Q from each of the evaporation modules 620, 630, and 640 according to the precipitation pattern 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 solid (S).

The second centrifugal separator 690 receives the soluble solid content precipitate (S ₁ ) in a slurry state mixed with the aqueous solution (Q) from the precipitate storage tank 680 to obtain a soluble solid content precipitate (S ₁ ) and an aqueous solution (Q). It is provided to enable centrifugation.

The second centrifuge 690 is preferably composed of a ContaVex centrifuge, but is not limited thereto. The second centrifugal separator 690 may have a second filter having a predetermined fourth reference particle size 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 centrifugal separator 690 may include residual soluble solids S that have not yet been precipitated by the evaporation modules 620, 630, and 640. have. Therefore, the second centrifugal separator 690 can deliver the soluble solids precipitate S ₁ to the soluble solids storage unit 70 and suction the aqueous solution Q through the flow path 692 through the raw water supply pump 610 You can redistribute it to wealth. The aqueous solution (Q) re-delivered to the raw water supply pump (610) is mixed with the aqueous solution (Q) supplied from the first centrifugal separator (56) to be re-supplied to the evaporation modules (620, 630, 640). have. Through this, the second centrifugal separator 690 can further increase the recovery rate of the soluble solid content (S) through the precipitation process.

FIG. 11 is a photograph of soluble solids precipitated and dried, FIG. 12 is a SEM-EDS chart that qualitatively analyzes the soluble solids shown in FIG. 11, and FIG. 13 is a chart showing the composition ratio of 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 solid content storage unit 70 is not particularly limited. For example, the soluble solid content storage unit 70 includes a soluble solid content dryer (72) for drying the soluble solid content precipitate (S ₁ ) and a dried product of the soluble solid content (S) dried by the soluble solid content dryer (72). , It may include a soluble solid content storage chamber 74 for storing the'soluble solids (S ₂ )'.

The soluble solids dryer 72 is a device for drying the soluble solids precipitate S ₁ separated from the aqueous solution Q1 by the second centrifugal separator 66.

The soluble solids precipitate (S ₁ ) and the aqueous solution (Q ₁ ) are separated by the second centrifugal separator 66, but some of the aqueous solutions (Q1) are not separated from the soluble solids precipitate (S ₁ ) and the soluble solids precipitate (S) It can be adsorbed on the surface of ₁ ). For this reason, the soluble solid precipitate (S ₁ ) separated from the aqueous solution (Q1) by the second centrifugal separator (66) is present in a slurry state by the aqueous solution (Q1) adsorbed on the surface. However, since the soluble solids precipitate S ₁ is not easily recycled when present in a slurry state, a soluble solids dryer 72 is provided to solve this.

The soluble solid content dryer 72 dries the soluble solid content precipitate S ₁ discharged from the second centrifugal separator 66 so that the soluble solid content S contains moisture below a predetermined reference moisture. The reference moisture is preferably about 0.3%, but is not limited thereto.

11 and 12, the soluble solid content dried product (S ₂ ) dried by the soluble solid content dryer 72 has a white powder form, and chlorides such as sodium chloride (NaCl) and potassium chloride (KCl). It mainly contains salt. The soluble solid content dryer 72 delivers the soluble solid content dried product S ₂ to the soluble solid content storage chamber 74 as described above.

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

The soluble solid content storage chamber 74 may be configured as a general storage chamber capable of storing a storage object. The soluble solid content storage chamber 74 receives the soluble solid content dried product S ₂ from the soluble solid content dryer 72 and stores it in an isolated state from the outside. As shown in FIGS. 12 and 13, the soluble solids dry matter S ₂ stored in the soluble solids storage chamber 74 mainly contains chloride salts contained in the flux F, and thus is recycled as the flux F It is preferred. However, the present invention is not limited thereto, and the soluble solid content dried product S ₂ may be recycled in various fields requiring mixed salt.

Next, the aluminum granule storage unit 80 is a device for storing the aluminum granules N discharged from the crushing/grinding unit 40.

The structure of the aluminum grain storage unit 80 is not particularly limited. For example, as illustrated in FIG. 7, the aluminum particle storage unit 80 is capable of storing aluminum particles N separated and discharged from the first separation member 42 and the second separation member 44. A grain storage chamber 82 may be included.

Next, the insoluble solid content storage unit 90 is a device for drying and storing the insoluble solid content (I) received from the first centrifugal separator (56).

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

14 is a photograph of insoluble solids that have been dried.

The insoluble solid content dryer 92 is a device for drying the insoluble solid content I separated from the aqueous solution Q by the first centrifugal separator 56.

The insoluble solid (I) is separated by distilled water and the first centrifugal separator (56), but some of the distilled water can be adsorbed on the surface of the insoluble solid (I) without being separated from the insoluble solid (I). For this reason, the insoluble solid content (I) discharged from the first centrifugal separator 56 is present in a slurry state, containing about 30 to 40% moisture. However, when the insoluble solid content (I) is present in a slurry state, since the transport and recycling of the insoluble solid content (I) is not easy, an insoluble solid content dryer 92 is provided to solve this.

The insoluble solid content dryer 92 dries the insoluble solid content I discharged from the first centrifugal separator 56 so that the insoluble solid content I contains moisture below a predetermined reference moisture.

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

As shown in FIG. 14, the insoluble solid content (I) dried by the insoluble solid content dryer 92 (hereinafter referred to as'insoluble solid content dried product I ₁ ') is dark gray due to the carbon component adsorbed on the surface. It has a powder form. The insoluble solid content dried product I ₁ is transferred to the insoluble solid content kiln 94.

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

The insoluble solid content kiln 94 is a device for firing the insoluble solid content dried product I ₁ .

When the finely divided aluminum, magnesium, and aluminum alloys contained in the dross particulate powder (P ₂ ) are decomposed by water, aluminum hydroxide, magnesium hydroxide, and aluminum alloy hydrates (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 centrifugal separator 56 and transferred to the insoluble solids dryer 92. However, since hydrates are materials that are unstable compared to aluminum oxide, magnesium oxide, and aluminum alloy oxides (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 solid content kiln 94.

The insoluble solid content kiln 94 heats the insoluble solid content dried product I ₁ to about 800° C. or higher to cause the hydrates to fire. Then, the hydrates are calcined and transferred to oxides, and at the same time, the carbon component adsorbed on the surface of the insoluble solid content I ₁ is burned. Therefore, as shown in FIG. 15, the insoluble solid content dried product I ₁ (hereinafter referred to as'insoluble solid content calcined product I ₂ )'calcined by the insoluble solid content calcination furnace 94 is light yellow powder. Becomes. The insoluble solid content calcination furnace 94 delivers the insoluble solid content calcined product I ₂ to the insoluble solid content storage chamber 96.

On the other hand, when the insoluble solid content kiln 94 has a structure capable of continuously performing a drying process and a firing process, such as a microwave kiln, the insoluble solid content dryer 92 may be omitted.

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

The insoluble solid content storage chamber 96 may be configured as a general storage chamber capable of storing a storage object. The insoluble solid content storage chamber 96 receives the insoluble solid content calcined product I ₂ from the insoluble solid content calcination furnace 94 and stores it in an isolated state from the outside. 16 and 17, the insoluble solid content calcined product I ₂ mainly includes aluminum oxide, magnesium oxide, and aluminum oxide alloy, and thus, after additional rehabilitation, ceramic material, refractory material, and cement material It is preferably recycled. The additional recycling process of the insoluble solid content calcined product (I ₂ ) is not particularly limited. For example, an additional recycling process of the insoluble solid content fired material (I ₂ ) may include a spinel manufacturing process in which aluminum oxide and magnesium oxide are fired at a temperature of about 2000° C. and transferred to spinel (MgAl ₂ 0 ₄ ).

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

The gas storage unit 100 may be configured as a gas storage chamber generally used to store 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) regenerates the normal black dross by injecting an exothermic flux such as cornerstone (NaNO ₃ ) into the normal black dross. When the retreated general black dross is decomposed by water, ammonia gas (NH ₃ ) and silane gas (SiH ₄ ) toxic to the human body are generated from aluminum nitride and aluminum silicide contained in the general black dross. Therefore, it is difficult to recycle the gas generated by water decomposition of the retreated ordinary black dross.

By the way, the spherical black dross (B ₂ ) is a hydrolysis gas (G) generated by treatment by the black dross recycling apparatus 3, hydrogen, methane, ethane, ethane, includes gas such as propane, propene, etc. do. Since these gases are not usable as the ammonia gas and silane gas described above as gases usable as an energy source, recycling is easy. In addition, since hydrogen and methane having excellent properties as an energy source occupy most of the hydrolysis gas (G), the hydrolysis gas (G) has a very good recycling value.

The 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 transported to the outside by a gas transfer facility, and may be 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 processed to be recyclable for the above-described spherical black dross (B ₂ ), 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 old black dross B ₂ to be recyclable.

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

Referring to Figure 18, aluminum dissolution and black dross recycling method according to a preferred embodiment of the present invention, the step of dissolving aluminum (S 100), and the spherical black dross generated when dissolving aluminum (B ₂ ) The step of crushing and crushing (S 200), and the step of decomposing water of the dross particulate powder (P ₂ ) formed by crushing and crushing the spherical black dross (B ₂ ) (S 300), and the dross particulate powder (P) _And treating at least one of the water decomposition products of ₂ ) to be recyclable (S400).

First, as shown in Figure 19, the step of dissolving aluminum (S 100), the step of forming a vortex (V) in the aluminum melt (M) (S 110), and melted on the surface of the aluminum melt (M) Injecting the flux (F) into the vortex (V) so that the flux layer is formed (S 120), and injecting the aluminum scrap (A) into the vortex (V) to pass through the molten flux layer (S 130), When the aluminum scrap (A) is dissolved in the molten aluminum (M), the aluminum scrap (A) is a step (S 140) of recovering the spherical black dross (B ₂ ) generated by the flux treatment by the molten flux layer.

In the step (S 110) of forming a vortex (V) in the aluminum molten metal (M), the aluminum molten metal (M) is stirred using the aforementioned vortex unit (21) that can be rotationally driven, and the aluminum molten metal (M) is turned to descend. Vortex V can be formed.

In the step S 120 of introducing the flux F into the vortex V, the flux F may be introduced into the vortex V of the aluminum molten metal M formed in 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 equal parts by weight, and 3-7 parts by weight of cryolite (Cryolite, Potassium Cryolite). More preferably, the flux (F) may include ₄ 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), that is, a salt bath layer is formed on the surface of the aluminum molten metal (M).

In the step of injecting the aluminum scrap (A) into the vortex (V) (S 130), the predetermined aluminum scrap (A) to the vortex (V) of the molten aluminum (M) to pass through the molten flux layer formed in step S 120. Can be injected. Preferably, the aluminum scrap (A) may be aluminum scrap 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) is dissolved in the aluminum molten metal (M). At the same time, the inclusions contained in the aluminum molten metal (M) are captured in the molten flux layer, that is, the flux (F) to form a black dross (B ₁ ), the black dross (B ₁ ) is in the vortex (V) By repeatedly descending and floating in the aluminum molten metal (M), a spherical black dross (B ₂ ) in which black dross (B ₁ ) is aggregated into a spherical shape is formed.

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 outlet of the aluminum melting furnace (2). 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 aluminum molten metal 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 The step of separating the granules (N) and the dross powder (P ₁ ) (S 220), the step of crushing the dross powder (P ₁ ) (S 230), and the aluminum granules (N) and the dross particulate powder ( And separating P ₂ ) (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 (S 220) of separating the aluminum granules (N) and the dross powder (P ₁ ), the aluminum granules (N) and the dross powder (P) among the crushed products of the spherical black dross (B ₂ ) formed in the step S 210. ₁ ) can be separated using the first separation member 42 described above. For example, the first separating member 42 may be configured as 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 (S 240) of separating the aluminum granules (N) and the dross particulate powder (P ₂ ), the aluminum granules (N) and the dross particulate powder among the pulverized powder of the dross powder (P ₁ ) formed in step S 230 (P ₂ ) can be separated using the second separation member 44 described above. 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 (200) of crushing and crushing the spherical black dross (B ₂ ), aluminum particles separated from the dross powder (P ₁ ) and the dross particulate powder (P ₂ ) in steps S 220 and S 240 (N) recycling step (S 250) may be further included. 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 aluminum molten metal M described above.

Next, in the step (S 300) of decomposing the dross particulate powder (P ₂ ) by water, the reactor 52 uses the dross particulate powder (P ₂ ) re-separated from the aluminum particles (N) in step S 240. It can be performed by decomposing water. Preferably, the reactor 52 may stir the dross particulate powder (P ₂ ) and water mixed in a ratio of 1: 2 to decompose the dross particulate powder (P ₂ ) into 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) Decomposes into

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

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

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

In the step of centrifuging the insoluble solid (I) and the aqueous solution (Q) (S 421), the first centrifugation of the insoluble solid (I) and the aqueous solution (Q) separated from the hydrolysis gas (G) in step S 410 Centrifugation may be performed using a separator 56.

In the step of washing the insoluble solid (I) with distilled water (S 422), in step S 421, the insoluble solid (I) is washed with distilled water so that chlorine adsorbed to the insoluble solid (I) is separated from the insoluble solid (I). Can be. Even if the insoluble solid content (I) and the aqueous solution (Q) are centrifuged in step S 421, some of the aqueous solution (Q) may remain adsorbed to the insoluble solid content (I), and the aqueous solution (Q) contains a chloride salt. Soluble solid content (S) is dissolved. Accordingly, the insoluble solid (I) is washed with distilled water to remove the chloride salt adsorbed on the insoluble solid (I). In the step of washing the insoluble solid (I) with distilled water (S 422), it is preferable to use the condensed water (D) produced in step S 445 to be described later as distilled water, but is not limited thereto.

In the step of centrifuging the insoluble solid content (I) and distilled water (S 423), after step S 422, the insoluble solid content (I) and distilled water may be centrifuged using the above-described first centrifugal separator (56).

Additionally, steps S 422 and S 423 may be repeatedly performed until the concentration of the chloride salt adsorbed on the insoluble solid content (I) becomes below a predetermined reference concentration. The reference concentration is preferably about 300 ppm, but is not limited thereto.

As shown in Figure 20, the step of treating the hydrolysis gas (G) to be recyclable (S 430), the step of removing the moisture contained in the hydrolysis gas (G) (S 431), the moisture is removed It includes the step of separating and purifying the hydrolyzed gas (G) (S 432), and the step of storing the separated and purified hydrolyzed gas (G) (S 433).

In the step (S 431) of removing the moisture contained in the hydrolysis gas (G), the moisture trap included in the moisture contained in the hydrolysis gas (G) collected by the gas collector 54 in step S 410 ( 54b), can be removed using a water remover (not shown) and a desulfurizer (not shown).

In the step (S 432) of separating and purifying the hydrolysis gas (G), the purity of the gas that is actually recyclable among the hydrolysis gases (G) from which moisture is removed in step S431 is increased, or the purpose of recycling in the gas separation gas (G) The hydrolysis gas (G) can be separated and purified using the above-described gas separation and purification (54a) so that a specific gas suitable for separation from other gases.

In the step (S 433) of storing the hydrolysis gas (G), the hydrolysis gas (G) separated and purified in step S432 may be stored in the gas storage unit 100 described above.

As shown in Figure 20, the step of treating the soluble solid (S) to be recyclable (S 440), using a plurality of evaporation modules (620, 630, 640), respectively, the water contained in the aqueous solution (Q) Evaporating 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 soluble solids precipitate (S) ₁ ) drying (S 443 ), and storing the soluble solid content (S ₂ ) (S 444 ).

In the step (S 441) of precipitating the soluble solid (S), by evaporating the water contained in the insoluble solid (I) and the centrifuged aqueous solution (Q) in step S 421 using each of the evaporation modules (620,630, 640) The soluble solid content (S) is precipitated from the aqueous solution (Q), but evaporation of water is induced under different environmental conditions for each of the evaporation modules (620, 630, 640), and thus different precipitation for each evaporation modules (620, 630, 640) Depending on the order and the timing of precipitation, sodium chloride and potassium chloride contained in the soluble solid (S) may be precipitated.

In addition, in the step (S 441) of precipitating the soluble solids (S), the evaporation modules (620, 630, 640) is separated from the insoluble solids (I) and the aqueous solution pumped by the raw water supply pump (610) (Q ) Is supplied. For example, the insoluble solids (I) and the separated aqueous solution (Q) can be supplied to the third evaporator 642 of the third evaporation module 640 by the raw water supply pump 610, the third evaporator 642 Part 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, and 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 the second circulation pump 633.

In addition, in the step (S 441) of precipitating the soluble solids (S), the evaporation modules (620, 630, 640) is used directly or indirectly as a heat source using the high temperature source steam (E) supplied from an external steam source Soluble solids (S) can be precipitated by heating the aqueous solution (Q) to evaporate the water. Here, the supply of the original steam (E) is preferably started in a state in which the aqueous solution (Q) is charged to a predetermined water level in the evaporator (622, 632, 642) of each of the evaporation modules (620, 630, 640).

For example, the first reboiler 621 of the first evaporation module 620 may heat the aqueous solution by 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 vapor (E ₁ ) generated by the evaporation of water in the first evaporator 622 with the aqueous solution (Q), and thus the aqueous solution (Q) Can be heated.

For example, the third reboiler 641 of the third evaporation module 640 heats the generated vapor (E ₂ ) generated by the evaporation of water from the second evaporator 632 with the aqueous solution (Q), and thus the aqueous solution (Q) Can be heated.

In the step (S 441) of precipitating these soluble solids (S), each of the evaporation modules (620, 630, 640), using the reboiler (621, 631, 641) the aqueous solution (Q) at a predetermined reference temperature After heating, the evaporator 622, 632, 642 is used to induce evaporation of water under the internal pressure of the evaporator 622, 632, 642 controlled so that the evaporation temperature of the water becomes a reference temperature to precipitate soluble solids (S). Can be. The reference temperature is the evaporation modules (620, 630, 640) of the evaporation modules (620, 630, 640) according to the deposition order and precipitation time of sodium chloride and potassium chloride to be implemented in the evaporation modules (620, 630, 640) Each can be set individually.

For example, the first evaporation module 620 uses the first reboiler 621 to reduce the solubility of sodium chloride in the aqueous solution Q by at least a predetermined first reference value compared to the solubility of potassium chloride. After heating the aqueous solution (Q) to a temperature, the first evaporator is induced by evaporating water under the internal pressure of the first evaporator 622, which is adjusted so that the evaporation temperature of water is the first reference temperature using the first evaporator 622, In (622), sodium chloride can be preferentially precipitated from a significantly earlier time 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 about 100° C. to 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%, and the internal pressure of the first evaporator (622). May be about 20 kPa which is an evaporation pressure of water of about 100°C to 110°C.

For example, the second evaporation module 630 uses a second reboiler 631, a second reference temperature at which the solubility of sodium chloride in the aqueous solution Q and the solubility of potassium chloride are lowered below a predetermined second reference value. After heating the furnace aqueous solution (Q), the evaporation of water is induced using the second evaporator 632 so that the evaporation temperature of the water is adjusted to the second reference temperature, thereby inducing evaporation of water to reduce sodium chloride and potassium chloride. It can be precipitated together from almost the same time point.

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

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

For example, the third reference temperature may be about 50° C. to 60° C., in which the solubility of sodium chloride in aqueous solution (Q) is about 30% and the solubility of potassium chloride is about 22%, and the internal pressure of the second evaporator (642). May be about -80 kPa, which is an 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 should be maintained in a vacuum state lower than atmospheric pressure. To this end, the second evaporation module 630 and the third evaporation module 640, respectively, the pressure control member 670 to induce reduced pressure evaporation of water under a vacuum atmosphere according to the second reference temperature or the third reference temperature The internal pressure may be kept constant by a vacuum pressure selectively applied from.

In addition, in the step (S 441) of precipitating the soluble solid (S), the original steam (E) or the generated steam (E ₁ , E ₂ ) in the process of exchanging heat with the aqueous solution (Q), the original steam (E) or generated steam (E ₁ , E ₂ ) The condensate (D) generated by cooling by the aqueous solution (Q) and the generated vapor (E ₂ , E ₃ ) discharged from the second evaporator 632 or the third evaporator 642 The condensate D generated by condensation in the condenser 650 may be stored in the condensate storage tank 660. As such, the condensate D stored in the condensate storage tank 660 may be transferred to the first centrifugal separator 56 (S 445). Then, in step S 422, the insoluble solids (I) separated from the aqueous solution (Q) by the first centrifugal separator (56) can be washed using the condensate (D) transferred from the condensate storage tank (660) as distilled water. .

In the step (S 442) of centrifuging the soluble solids precipitate (S ₁ ) and the aqueous solution (Q), the soluble solids precipitate (S ₁ ) and the soluble solids precipitate (S ₁ ) precipitated from the aqueous solution (Q) in step S 441 are The remaining aqueous solution Q precipitated may be centrifuged using the second centrifuge 690 described above. The aqueous solution (Q) separated from the soluble solids precipitate (S ₁ ) is evaporated so that the soluble solids (S) remaining dissolved in the aqueous solution (S) without precipitation can be precipitated from the aqueous solution (Q). It may be re-delivered to the modules (620, 630, 640) (S 446). Then, in step S 441, the evaporation modules 620, 630, and 640 are used to reprecipitate the soluble solids (S) from the aqueous solution (Q) separated from the soluble solids precipitate (S ₁ ) in step S 442. .

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 this soluble solid precipitate (S ₁₎ (S 443), the soluble solid precipitate (S ₁₎ one or desirable to perform up to and including a moisture of not more than 0.3%, and the like.

Storing the soluble solid dry product (S ₂₎ (S 444) In, can be stored in a soluble solid the reservoir chamber 74 above the soluble solid dry product (S ₂₎ and dried at S 443 step.

As shown in FIG. 20, the step of treating the insoluble solid content (I) to be recyclable (S 450) includes: drying the insoluble solid content (I) (S 451) and firing the insoluble solid content (I ₁ ). It includes a step (S 452) and a step (S 453) of storing the insoluble solid content fired material (I ₂ ).

In the step of drying the insoluble solid (I) (S 451), in step S 420, the water adsorbed on the insoluble solid (I) without being separated from the insoluble solid (I) is dried using the above-described insoluble solid content dryer (92). can do. In the step (S 451) of drying the insoluble solid content (I), when recycling the insoluble solid content (I) as a cement raw material, it is preferable to perform it until the insoluble solid content dry matter (I ₁ ) contains 40% or less of moisture. Do. In addition, the step of drying the insoluble solid content (I ₁ ) (S 451), when recycling the insoluble solid content (I) as a brick refractory material or ceramic material, the insoluble solid content (I ₁ ) contains less than 0.5% moisture It is preferable to perform until, but is 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. The insoluble solid content (I ₁ ) may include hydroxides such as aluminum hydroxide, magnesium hydroxide, and aluminum alloy hydrates having unstable properties, so that these hydroxides are converted to aluminum oxide, magnesium oxide, and aluminum alloy oxides having relatively stable properties. It is to fire insoluble solids (I ₁ ).

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 way of limited examples and drawings, the present invention is not limited by this, and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the equal scope of the claims.

Claims (31)

1. (A) when dissolving an aluminum scrap in an aluminum molten metal, the aluminum scrap is crushed and pulverized by a flux treatment by a flux containing sodium chloride and potassium chloride, and crushed and pulverized to divide into aluminum particles 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 to deposit the soluble solids from the aqueous solution, but inducing the evaporation of the water under different environmental conditions for each of the evaporation modules, so that the evaporation module Black dross recycling method comprising the step of precipitating the sodium chloride and the potassium chloride according to a different precipitation order and precipitation timing for each.
2. According to claim 1,

   In step (c), each of the evaporation modules, after heating the aqueous solution to a predetermined reference temperature using a reboiler, the internal pressure of the evaporator adjusted so that the evaporation temperature of the water is the reference temperature using an evaporator Black dross recycling method, characterized in that to induce evaporation of the water under, to precipitate the soluble solids.
3. According to claim 2,

   The reference temperature, black dross recycling method, characterized in that determined separately for each of the evaporation modules according to the precipitation order and the precipitation order of the sodium chloride and the potassium chloride to be implemented in the evaporation module among the evaporation modules.
4. According to claim 3,

   In step (c), at least one evaporation module among the evaporation modules, the solubility of the sodium chloride in the aqueous solution is lowered by a predetermined first reference value or more than the solubility of the potassium chloride using the reboiler. After heating the aqueous solution to a first reference temperature, the evaporator is used to induce evaporation of the water under the internal pressure of the evaporator adjusted so that the evaporation temperature of the water becomes the first reference temperature, so that the sodium chloride is added to the potassium chloride. Compared to the black dross recycling method characterized in that the precipitation preferentially.
5. According to claim 3,

   In step (c), at least one of the evaporation modules of the evaporation module, the difference between the solubility of the sodium chloride and the solubility of the potassium chloride in the aqueous solution using the reboiler is lower than a predetermined second reference value After heating the aqueous solution to a second reference temperature, the evaporator is used to induce evaporation of the water under the internal pressure of the evaporator adjusted so that the evaporation temperature of the water becomes the second reference temperature, so that the sodium chloride and the potassium chloride are Black dross recycling method characterized in that the precipitation together.
6. According to claim 3,

   In step (c), at least one of the evaporation modules of the evaporation module, the solubility of the potassium chloride in the aqueous solution using the reboiler is lowered below a predetermined third reference value compared to the solubility of the sodium chloride After heating the aqueous solution to a third reference temperature, the potassium chloride is preferentially precipitated in comparison with the sodium chloride under the internal pressure of the evaporator adjusted so that the evaporation temperature of the water is the third reference temperature using the evaporator. Characterized by the black dross recycling method.
7. According to claim 2,

   In step (c), at least one evaporation module among the evaporation modules may be vacuum pressure selectively applied from a pressure regulating member to induce reduced pressure evaporation of the water under a vacuum atmosphere according to the predetermined reference temperature. Black dross recycling method characterized in that the internal pressure of the evaporator is maintained in a vacuum.
8. According to claim 1,

   (d) further comprising the step of centrifuging the soluble solids precipitate precipitated from the aqueous solution and the aqueous solution mixed with the soluble solids precipitate,

   In the step (c), the method for recycling black dross, characterized in that by reusing the evaporation modules, the soluble solid content is re-precipitated from the aqueous solution separated from the soluble solid content precipitate in the step (d).
9. The method of claim 8,

   (E) black dross recycling method further comprising the step of drying and storing the soluble solid precipitate separated from the aqueous solution in the step (d).
10. According to claim 1,

    In step (c), at least one of the evaporation modules, the evaporation module heats the aqueous solution by exchanging the aqueous solution with the original steam supplied from an external steam source,

    In step (c), at least one evaporation module among the evaporation modules is generated from the evaporation module generated by the water being evaporated in the at least one evaporation module or another evaporation module among the evaporation modules. Black dross recycling method, characterized in that for heating the aqueous solution by heat-exchanging the aqueous vapor generated by the evaporation of the water.
11. The method of claim 10,

    (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, black dross recycling method characterized in that to precipitate the soluble solids from the aqueous solution separated from the insoluble solids.
12. The method of claim 11,

    (g) using the condensed water generated by cooling the original steam or the generated steam by the aqueous solution or condensed water generated by condensing the original steam or the generated steam by the condenser, and separated from the aqueous solution in step (f). Black dross recycling method further comprising the step of washing the insoluble solids.
13. When dissolving aluminum scrap in an aluminum molten metal, in the black dross recycling apparatus for recycling the black dross generated by the aluminum scrap is fluxed by a flux containing sodium chloride and potassium chloride,

    A water decomposition unit that hydrolyzes the dross particulate powder, which is a pulverized product of the black dross, with water to generate an aqueous solution in which a soluble solid containing the sodium chloride and the potassium chloride is dissolved; And

    Evaporating the water contained in the aqueous solution to precipitate the soluble solids from the aqueous solution, respectively, and inducing the evaporation of the water under different environmental conditions to precipitate the sodium chloride and the potassium chloride according to different precipitation order and precipitation time. Black dross recycling apparatus comprising a precipitation unit having a plurality of evaporation modules.
14. The method of claim 13,

    At least one of the evaporation modules, the evaporation module, induces the evaporation of the water under a temperature condition at which the solubility of the potassium chloride in the aqueous solution is lower than or equal to a predetermined reference value than the solubility of the sodium chloride, so that the potassium chloride is the sodium chloride. Compared to the black dross recycling apparatus characterized in that the precipitation preferentially.
15. The method of claim 14,

    The at least one evaporation module is characterized in that at least one of the evaporation modules, the evaporation module generated by the evaporation of the water is used as a heat source for heating the aqueous solution in the evaporation module characterized in that the black Dross recycling device.
16. The method of claim 14,

    The at least one evaporation module, so that the water can be evaporated under the temperature condition, the black dross recycling apparatus characterized in that to induce reduced pressure evaporation of the water under a vacuum atmosphere.
17. The method of claim 14,

    At least one other evaporation module among the evaporation modules induces the evaporation of the water under temperature conditions such that the solubility of the sodium chloride in the aqueous solution is lower than or equal to a predetermined reference value compared to the solubility of the potassium chloride, so that the sodium chloride is the potassium chloride. Compared to the black dross recycling apparatus characterized in that the precipitation preferentially.
18. The method of claim 13,

    Each of the evaporation modules,

    A reboiler for heating the aqueous solution to a predetermined reference temperature; And

    The evaporator for receiving the aqueous solution heated to the reference temperature from the reboiler and inducing the evaporation of the water under an internal pressure regulated such that the evaporation temperature of the water becomes the predetermined reference temperature, thereby depositing the soluble solid content. Black dross recycling device, characterized in that.
19. The method of claim 18,

    Each of the evaporation modules,

    Black dross recycling apparatus further comprising a circulation pump for circulating the aqueous solution to the reboiler and the evaporator in a predetermined order.
20. The method of claim 18,

    The precipitation unit,

    A black dross recycling apparatus further comprising a centrifugal separator for centrifuging the soluble solid content precipitates and the aqueous solution in which the soluble solid content is deposited.
21. The method of claim 20,

    The precipitation unit,

    The soluble solid content precipitate discharged from the evaporator of at least one of the evaporation modules in a slurry state mixed with the aqueous solution is stored, and a precipitate storage tank for delivering the soluble solid content precipitate in the slurry state to the centrifugal separator is further provided. Black dross recycling device, characterized in that provided.
22. The method of claim 20,

    The centrifuge is a black dross recycling apparatus characterized in that the redistribution of the aqueous solution separated from the soluble solids precipitate to the evaporation modules.
23. The method of claim 22,

    And a soluble solids storage unit for drying and storing the soluble solids precipitate separated from the aqueous solution by the winshim separator.
24. The method of claim 18,

    The reboiler of at least one of the evaporation modules heats the aqueous solution using the original steam supplied from an external steam source as a heat source,

    The reboiler of at least one evaporation module among the evaporation modules may be generated by evaporation of the water in the evaporator of the at least one evaporation module or another evaporation module among the evaporation modules. Black dross recycling apparatus, characterized in that the aqueous solution is heated by using the steam generated by the evaporation of water in the evaporator as a heat source.
25. The method of claim 18,

    The reference temperature and the internal pressure for each of the evaporation modules, black dross recycling apparatus characterized in that it is individually determined according to the type of chloride salt to be preferentially precipitated in the evaporation module of the sodium chloride and the potassium chloride. .
26. The method of claim 25,

    The reference temperature in the evaporation module to preferentially precipitate the potassium chloride among the evaporation modules, the temperature at which the solubility of the potassium chloride in the aqueous solution is lowered by a predetermined reference value or more compared to the solubility of the sodium chloride is the water Is set to be the evaporation temperature,

    The internal pressure in the evaporation module to preferentially precipitate the potassium chloride among the evaporation modules, the black dross recycling apparatus characterized in that the water contained in the aqueous solution is adjusted to evaporate at the evaporation temperature.
27. The method of claim 25,

    The reference temperature in the evaporation module to preferentially precipitate the sodium chloride among the evaporation modules, the temperature at which the solubility of the sodium chloride in the aqueous solution is lowered by a predetermined reference value or more compared to the solubility of the potassium chloride is the water Is set to be the evaporation temperature,

    The internal pressure in the evaporation module to preferentially precipitate the sodium chloride among the evaporation modules, the black dross recycling apparatus characterized in that the water contained in the aqueous solution is adjusted to evaporate at the evaporation temperature.
28. The method of claim 25,

    The precipitation unit,

    It characterized in that it further comprises a pressure control member capable of inducing reduced pressure evaporation of the water under a vacuum atmosphere according to the reference temperature in the evaporator by adjusting the internal pressure of the evaporator of at least one of the evaporation modules. Black dross recycling device.
29. The method of claim 28,

    The pressure adjusting member,

    A vacuum tank in which a predetermined vacuum pressure is maintained; And

    Black dross recycling apparatus, characterized in that it has at least one vacuum control valve for controlling the internal pressure by selectively applying the vacuum pressure to the evaporator of the at least one evaporation module.
30. The method of claim 18,

    The precipitation unit,

    And a raw water supply pump for supplying the aqueous solution generated in the water decomposition unit to the evaporator of at least one of the evaporation modules.
31. The method of claim 30,

    The evaporator of the at least one evaporation module may transmit the aqueous solution supplied from the raw water supply pump to the evaporator of at least one evaporation module among the evaporation modules, so that the Black dross recycling device, characterized in that connected to the evaporator.

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