CN113943868A

CN113943868A - Method for separating metal aluminum from aluminum ash in supergravity enhanced manner

Info

Publication number: CN113943868A
Application number: CN202111208409.9A
Authority: CN
Inventors: 高金涛; 郭占成; 汪增武; 兰茜; 钟怡玮; 郭磊; 王哲
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2021-10-18
Filing date: 2021-10-18
Publication date: 2022-01-18

Abstract

The invention discloses a method for separating metal aluminum in aluminum ash by supergravity reinforcement, which relates to the technical field of aluminum ash harmlessness and resource recovery, and comprises the following steps: step 1, heating aluminum ash to 660-800 ℃ until metal aluminum particles in the aluminum ash are melted into metal aluminum droplets; and 2, carrying out supergravity separation on the product obtained in the step 1, wherein the method can utilize a supergravity field to generate huge shearing force to strip the metal aluminum liquid drops from the oxide shell, so as to realize efficient and rapid separation of metal aluminum in the aluminum ash.

Description

Method for separating metal aluminum from aluminum ash in supergravity enhanced manner

Technical Field

The invention relates to the technical field of aluminum ash harmlessness and resource recovery, in particular to a method for separating metal aluminum in aluminum ash in a supergravity reinforced manner.

Background

Aluminum ash is the waste slag from the aluminum or aluminum alloy smelting process, in which a large number of fine metallic aluminum particles are entrained. 30-50 kg of aluminum ash is generated when one ton of raw aluminum is smelted. The aluminum ash is generally divided into primary aluminum ash and secondary aluminum ash according to the generation and treatment process of the aluminum ash. Wherein, the primary aluminum ash refers to dross directly taken out of an aluminum smelting furnace, and the content of metallic aluminum is about 15-70%. At present, the processes of ash frying and the like are mainly adopted in China to recover part of metal aluminum in primary aluminum ash, and the residual waste residue after treatment is called secondary aluminum ash which still contains 12 to 18 percent of metal aluminum. The secondary aluminum ash is generally subjected to wet processes such as acid leaching or alkali dissolution to further recover residual metallic aluminum and compounds, and the residual waste residues after wet treatment are piled up or buried. At present, a large-scale treatment process of aluminum ash is not formed, so that a large amount of aluminum ash is accumulated, and great threats are caused to environmental ecology and human health.

The aluminum ash contains various harmful components such as salts, heavy metals, carbides, nitrides, cyanides and the like. Wherein, the aluminum carbide, the aluminum nitride, the aluminum oxide, the aluminum arsenide, the aluminum sulfide and the like are easy to generate CH in a humid environment or in a contact process with a water body₄、NH₃、H₂、AsH₃And H₂S and other flammable and toxic gases cause serious harm to human bodies, animals, plants, water bodies, environment and the like. In the published national hazardous waste record updated in 2021, waste residues generated by the maintenance and abandonment of an electrolytic cell in the aluminum electrolysis process, primary smelting slag generated in the aluminum pyrometallurgical process, salt slag and scum generated in the aluminum electrolysis process, and inflammable skimming slag generated in the aluminum pyrometallurgical process are definitely determined as HW48 type nonferrous metal smelting wastes (waste codes 321-026-48).

At present, the treatment process of the aluminum ash mainly comprises a fire method and a wet method. The pyrogenic process mainly aims at primary aluminum ash with high metal aluminum content, the temperature of the aluminum ash is higher than the aluminum melting point through the heat contained in the aluminum ash and an external heating source, and the metal aluminum liquid is promoted to be dripped, gathered and separated by adopting stirring and other modes. At present, the pyrogenic process mainly adopts a ash frying mode, and the method can cause oxidation of a large amount of metal aluminum, so that the recovery rate of aluminum is reduced, and a large amount of secondary aluminum ash is generated; in addition, a large amount of fine dust and irritant gas are generated in the ash frying process, and harm is caused to the atmosphere and human health. The wet process is usually used for treating secondary aluminum ash, metal aluminum and compounds in the aluminum ash are leached by methods such as acid leaching, alkali dissolving, organic solvent extraction and the like, and the content of the metal aluminum in the waste residue after the wet process treatment can be reduced to 3-5%.

Disclosure of Invention

The invention develops a method for separating metal aluminum in aluminum ash by supergravity reinforcement based on harmlessness and resource recovery of the aluminum ash.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a method for separating metal aluminum in aluminum ash by supergravity reinforcement, which comprises the following steps:

step 1, heating aluminum ash to 660-800 ℃ until metal aluminum particles in the aluminum ash are melted into metal aluminum droplets;

and 2, carrying out supergravity separation on the product obtained in the step 1. And (2) stripping the metallic aluminum liquid drops in the step (1) from the oxide shell by utilizing a huge shearing force generated by a supergravity field, driving the metallic aluminum liquid drops to pass through the porous filtering plate, intercepting residues inside the porous filtering plate, enabling the metallic aluminum liquid to flow into a liquid collecting tank from a liquid outlet, and enabling the residues to flow into a slag collecting tank from a slag outlet, thereby realizing the full separation of the metallic aluminum in the aluminum ash.

Further, the aluminum ash comprises primary aluminum ash generated in the aluminum or aluminum alloy smelting process and secondary aluminum ash generated by treatment processes such as ash frying and the like.

Furthermore, the gravity coefficient G in the hypergravity separation process is 300-1500.

Further, the separation time of the metallic aluminum droplets in the supergravity separation process is 1-5 min.

Further, the high-gravity separation uses a high-gravity field to generate a large shearing force to strip the metallic aluminum liquid drops in the step 1 from the oxide shell and drive the metallic aluminum liquid drops to pass through the porous filter plate.

Furthermore, the aperture of the porous filter plate is 0.01-0.1 mm.

Further, the step 2 also comprises adding 1 wt% -3 wt% of chloride (based on the mass of the aluminum ash added in the step 1) to accelerate the decomposition of the metal aluminum oxide shell. The chloride salt comprises NaCl or KCl.

The invention also provides equipment applied to the method for separating the metal aluminum in the aluminum ash by the supergravity reinforcement, which comprises the following steps:

the supergravity high-temperature reactor is used for carrying out supergravity reinforced separation on aluminum ash, and a side plate of the supergravity high-temperature reactor is a porous filter plate; the top of the hypergravity high-temperature reactor is provided with a feed inlet, and the bottom of the hypergravity high-temperature reactor is provided with a slag outlet;

the motor and the transmission system are fixed on the supporting platform and used for driving the high-gravity high-temperature reactor to rotate;

the heat preservation system is arranged on the outer surface of the supergravity high-temperature reactor; a heating system is arranged between the heat preservation system and the high-gravity high-temperature reactor; the heating system and the hypergravity high-temperature reactor are cavities, and liquid outlets for flowing out metal aluminum liquid drops are formed in the bottoms of the cavities.

Further, the slag collecting device also comprises a slag collecting groove and a liquid collecting groove, wherein the slag collecting groove is used for collecting the slag flowing out of the slag outlet; the liquid collecting tank is used for collecting the metal aluminum liquid drops flowing out of the liquid outlet.

Furthermore, a temperature thermocouple is arranged in the heating system.

During the equipment uses, the aluminium ash is packed into aluminium ash and is poured the package into, gets into in the hypergravity high temperature reactor through the feed inlet, through heating system, temperature thermocouple, the heating and the accuse temperature of thermal insulation system control hypergravity high temperature reactor, through motor and transmission system drive hypergravity high temperature reactor centrifugation rotation on supporting platform, drive metallic aluminum liquid drop flows into by the liquid outlet through porous filter and receives the cistern, detains the residue inside and flows into by the slag notch and receive the sediment groove at porous filter to realize the abundant separation of metallic aluminum in the aluminium ash.

The invention discloses the following technical effects:

the invention develops a method for strengthening and separating fine metallic aluminum liquid drops in aluminum ash. The invention can utilize the super-gravity field to generate huge shearing force to strip the metal aluminum liquid drops from the oxide shell, thereby realizing the high-efficiency and quick separation of the metal aluminum in the aluminum ash. The method can fully recover the fine metallic aluminum particles carried in the primary aluminum ash and the secondary aluminum ash, remarkably improve the separation efficiency and the recovery rate of the metallic aluminum, and avoid the aluminum resource waste and the environmental pollution caused by the traditional processes of ash frying and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a schematic view of an apparatus for separating metallic aluminum from aluminum ash by supergravity enhanced separation, wherein 1-aluminum ash dumping bag, 2-feeding port, 3-temperature thermocouple, 4-supergravity high-temperature reactor, 5-porous filter plate, 6-slag outlet, 7-slag collecting tank, 8-motor and transmission system, 9-supporting platform, 10-liquid collecting tank, 11-liquid outlet, 12-heating system and 13-heat preservation system;

FIG. 2 is a macro-topography and SEM image of example 1 separating metallic aluminum from residue;

FIG. 3 is an EDS diagram of example 1 for separating metallic aluminum from residues;

FIG. 4 is a macro-topography and SEM image of example 2 separating metallic aluminum from residue;

FIG. 5 is an EDS diagram of example 2 for separating aluminum metal from residue;

FIG. 6 is a macro-topography and SEM image of example 3 separating metallic aluminum from residue;

FIG. 7 is an EDS diagram of example 3 for separating aluminum metal from the residue.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The equipment for separating the metal aluminum in the aluminum ash by the supergravity enhancement is shown in a schematic diagram 1, wherein 1-the aluminum ash is poured into a ladle, 2-a feed inlet, 3-a temperature thermocouple, 4-a supergravity high-temperature reactor, 5-a porous filter plate, 6-a slag outlet, 7-a slag collecting groove, 8-a motor and transmission system, 9-a supporting platform, 10-a liquid collecting groove, 11-a liquid outlet, 12-a heating system and 13-a heat preservation system.

The process for separating the metal aluminum in the aluminum ash by using the supergravity of the equipment comprises the following steps: the aluminum ash is filled into the aluminum ash pouring bag 1, the aluminum ash enters the hypergravity high-temperature reactor 4 through the feeding hole 2, the heating system 12 is used, the temperature thermocouple 3 is used for measuring the temperature, the heat preservation system 13 controls the heating and temperature control of the hypergravity high-temperature reactor 4, the hypergravity high-temperature reactor 4 is driven to rotate centrifugally on the supporting platform 9 through the motor and the transmission system 8, metal aluminum liquid drops are driven to flow into the liquid receiving tank 10 through the porous filter plate 5 from the liquid outlet 11, residues are intercepted inside the porous filter plate 5 and flow into the slag receiving tank 7 from the slag outlet 6, and therefore the sufficient separation of the metal aluminum in the aluminum ash is achieved.

Example 1

Step 1, 300kg of primary aluminum ash (main technical indexes are Al 41.4 percent and Al) of Shanxi aluminum factory₂O₃ 29.4％，SiO₂ 1.41％，MgO 4.64％，K₂O 5.41％，Na₂O3.72 percent, Cl 3.02 percent and F1.24 percent) are filled into an aluminum ash pouring ladle 1, and the aluminum ash is fed into a high-gravity high-temperature reactor 4 through a feeding hole 2, the internal temperature of the high-temperature reactor 4 is controlled to be 660 ℃, until metal aluminum particles in the aluminum ash are melted into metal aluminum droplets.

And 2, starting centrifugal rotation, controlling the internal gravity coefficient of the high-temperature reactor 4 to be 1500, separating for 1min, stripping the metallic aluminum droplets from the oxide shell by using a huge shearing force generated by a supergravity field, driving the metallic aluminum droplets to pass through a porous filter plate 5 (the pore diameter is 0.01mm), and intercepting residues inside the porous filter plate 5.

And 3, flowing the molten metal aluminum into a liquid collecting tank 10 from a liquid outlet 11, and flowing the residues into a residue collecting tank 7 from a residue outlet 6.

The metallic aluminum flowing into the liquid collecting tank 10 and the residue flowing into the residue collecting tank 7 are sampled and analyzed, and the macro-morphology, SEM and EDS diagrams of the metallic aluminum and the residue obtained by separation are respectively shown in FIGS. 2 and 3. As can be seen from FIGS. 2 and 3, the metal aluminum and the residue are separated efficiently, the purity of the separated metal aluminum and the purity of the residue are both very high, the separated metal aluminum does not contain any impurities, and the main component of the separated residue is Al₂O₃Without clips thereinAny metallic aluminum particles are mixed.

In the embodiment, a huge shearing force is generated by using a supergravity field, so that metallic aluminum liquid drops in primary aluminum ash in Shanxi aluminum factories are peeled from an oxide shell, the metallic aluminum liquid is driven to flow into the liquid collecting tank 10 from the liquid outlet 11, and residues flow into the slag collecting tank 7 from the slag outlet 6, so that the efficient and rapid separation of the metallic aluminum in the primary aluminum ash is realized. In the embodiment, the content of metal Al in the separated aluminum liquid reaches 99.40 percent, the content of metal Al in the residues is as low as 0.10 percent, and the recovery rate of metal Al in the aluminum liquid reaches as high as 99.60 percent.

Example 2

Step 1, 400kg of secondary aluminum ash (the main technical indexes are 18.2 percent of Al and 18.2 percent of Al) from Shanxi aluminum factories₂O₃ 28.3％，SiO₂ 8.49％，MgO 12.2％，K₂O 5.41％，Na₂O2.83 percent, Cl 8.08 percent and F1.62 percent) are filled into the aluminum ash pouring ladle 1, and the aluminum ash is fed into the supergravity high-temperature reactor 4 through the feeding hole 2, the internal temperature of the supergravity high-temperature reactor 4 is controlled to be 800 ℃, until the metal aluminum particles in the aluminum ash are melted into metal aluminum droplets.

And 2, starting centrifugal rotation, controlling the internal gravity coefficient of the high-gravity high-temperature reactor 4 to be 300, separating for 5min, stripping the metallic aluminum droplets from the oxide shell by using a huge shearing force generated by a high-gravity field, driving the metallic aluminum droplets to pass through a porous filter plate 5 (the pore diameter is 0.1mm), and trapping residues inside the porous filter plate 5.

The metallic aluminum flowing into the liquid collecting tank 10 and the residue flowing into the residue collecting tank 7 are sampled and analyzed, and the macro-morphology, SEM and EDS diagrams of the metallic aluminum and the residue obtained by separation are respectively shown in FIGS. 4 and 5. As can be seen from FIGS. 4 and 5, the high-efficiency separation of the metallic aluminum from the residue is realized, the purity of the separated metallic aluminum and the purity of the residue are both very high, the separated metallic aluminum is free from any impurities, and the main component of the separated residue is Al₂O₃Without any metallic aluminum particles being entrapped therein.

In the embodiment, a huge shearing force is generated by using a supergravity field, so that metallic aluminum liquid drops in secondary aluminum ash in Shanxi aluminum factories are peeled from an oxide shell, the metallic aluminum liquid is driven to flow into the liquid collecting tank 10 from the liquid outlet 11, and residues flow into the slag collecting tank 7 from the slag outlet 6, so that the efficient and rapid separation of the metallic aluminum in the secondary aluminum ash is realized. In the embodiment, the content of metal Al in the separated aluminum liquid reaches 99.20%, the content of metal Al in the residues is as low as 0.08%, and the recovery rate of metal Al in the aluminum liquid reaches as high as 99.10%.

Example 3

Step 1, filling 400kg of secondary aluminum ash from Shanxi aluminum factories into an aluminum ash dumping bag 1, feeding the aluminum ash into a supergravity high-temperature reactor 4 through a feeding hole 2, controlling the internal temperature of the supergravity high-temperature reactor 4 to be 800 ℃ until metal aluminum particles in the aluminum ash are melted into metal aluminum droplets.

And 2, adding 4kg of KCl, starting centrifugal rotation, controlling the internal gravity coefficient G of the high-gravity high-temperature reactor 4 to be 1200, separating for 1min, stripping the metallic aluminum droplets from the oxide shell by using huge shearing force generated by a high-gravity field, driving the metallic aluminum droplets to pass through a porous filter plate 5 (the pore diameter is 0.01mm), and intercepting residues inside the porous filter plate 5.

The metallic aluminum flowing into the liquid collecting tank 10 and the residue flowing into the residue collecting tank 7 are sampled and analyzed, and the macro-morphology, SEM and EDS diagrams of the metallic aluminum and the residue obtained by separation are respectively shown in FIGS. 6 and 7. As can be seen from FIGS. 6 and 7, the metal aluminum and the residue are separated efficiently, the purity of the separated metal aluminum and the purity of the residue are both very high, the separated metal aluminum does not contain any impurities, and the main component of the separated residue is Al₂O₃Without any metallic aluminum particles being entrapped therein.

In the embodiment, a huge shearing force is generated by using a supergravity field, so that metallic aluminum liquid drops in secondary aluminum ash in Shanxi aluminum factories are peeled from an oxide shell, the metallic aluminum liquid is driven to flow into the liquid collecting tank 10 from the liquid outlet 11, and residues flow into the slag collecting tank 7 from the slag outlet 6, so that the efficient and rapid separation of the metallic aluminum in the secondary aluminum ash is realized. In the embodiment, the content of metal Al in the separated aluminum liquid reaches 99.25%, the content of metal Al in the residues is as low as 0.05%, and the recovery rate of metal Al in the aluminum liquid reaches as high as 99.45%.

Example 4

The difference from example 3 is only that the gravity coefficient G is 300 and the separation time is 3 min.

In the embodiment, the content of metal Al in the separated aluminum liquid reaches 99.18%, the content of metal Al in the residues is as low as 0.12%, and the recovery rate of metal Al in the aluminum liquid reaches as high as 99.37%.

Comparative example 1

The difference from example 1 is only that the gravity coefficient G is 100.

In the embodiment, the content of the metal Al in the separated aluminum liquid is 99.03%, the content of the metal Al in the residue is 23.78%, and the recovery rate of the metal Al in the aluminum liquid is 42.36%.

Comparative example 2

The difference from example 1 is only that the gravity coefficient G is 200.

In the embodiment, the content of metal Al in the separated aluminum liquid is 99.09%, the content of metal Al in the residue is 21.19%, and the recovery rate of metal Al in the aluminum liquid is 51.17%.

As can be seen from example 1 and comparative examples 1 and 2, the gravity coefficient significantly affects the content of metallic Al in the slag and the recovery rate of metallic Al in the molten aluminum.

Comparative example 3

The only difference from example 1 is that the separation time t is 0.5 min.

In the embodiment, the content of metal Al in the separated aluminum liquid is 99.03%, the content of metal Al in the residue is 17.15%, and the recovery rate of metal Al in the aluminum liquid is 58.22%.

As can be seen from example 1 and comparative example 3, the separation time also significantly affects the content of metallic Al in the slag and the recovery rate of metallic Al in the molten aluminum.

Comparative example 4

The only difference from example 1 is that the separation temperature T is 900 ℃.

In the embodiment, the content of metal Al in the separated aluminum liquid is 99.01%, the content of metal Al in the residue is 33.91%, and the recovery rate of metal Al in the aluminum liquid is 17.43%.

As can be seen from example 1 and comparative example 4, the separation temperature significantly affects the content of metallic Al in the slag and the recovery rate of metallic Al in the molten aluminum.

Comparative example 5

The difference from example 1 is only that the pore size of the filter plate is 0.2 mm.

In the embodiment, the content of metal Al in the separated aluminum liquid is 60.37%, the content of metal Al in the residue is 0.21%, and the recovery rate of metal Al in the aluminum liquid is 97.91%.

From example 1 and comparative example 5, it can be seen that the pore size of the filter plate significantly affects the purity of separated Al, and does not affect the separation efficiency (content and recovery).

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, are merely for convenience of description of the present invention, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims

1. A method for separating metal aluminum from aluminum ash in a supergravity reinforced manner is characterized by comprising the following steps:

step 1, heating the aluminum ash to 660-800 ℃ until metal aluminum particles in the aluminum ash are melted into metal aluminum droplets;

and 2, carrying out supergravity separation on the product obtained in the step 1.

2. The method for separating the metallic aluminum in the aluminum ash by the supergravity enhanced separation as claimed in claim 1, wherein the aluminum ash comprises primary aluminum ash produced in the aluminum or aluminum alloy smelting process and secondary aluminum ash produced in the ash frying treatment process.

3. The method for separating the metallic aluminum in the aluminum ash by the enhanced supergravity according to claim 1, wherein a gravity coefficient G in the supergravity separation process is 300-1500.

4. The method for separating the metallic aluminum in the aluminum ash by the supergravity enhanced separation according to claim 1, wherein the separation time of the metallic aluminum droplets in the supergravity separation process is 1-5 min.

5. The method of claim 1, wherein the step 1 of separating the metallic aluminum droplets from the oxide shell by using the huge shearing force generated by the supergravity field and driving the metallic aluminum droplets to pass through the porous filter plate.

6. The method for separating aluminum metal from aluminum ash by supergravity enhanced separation according to claim 5, wherein the pore size of the porous filter plate is 0.01-0.1 mm.

7. The method for separating the metallic aluminum in the aluminum ash by the supergravity enhanced method as claimed in claim 1, wherein the step 2 further comprises adding 1 wt% to 3 wt% of chloride salt.

8. The equipment applied to the supergravity-enhanced method for separating the metallic aluminum from the aluminum ash as claimed in any one of claims 1 to 7 is characterized by comprising the following steps:

the hypergravity high-temperature reactor (4) is used for performing hypergravity reinforced separation on aluminum ash, and a side plate of the hypergravity high-temperature reactor (4) is a porous filter plate (5); the top of the hypergravity high-temperature reactor (4) is provided with a feed inlet (2), and the bottom of the hypergravity high-temperature reactor (4) is provided with a slag outlet (6);

the motor and transmission system (8) is fixed on the supporting platform (9) and used for driving the super-gravity high-temperature reactor (4) to rotate;

the heat preservation system (13) is arranged on the outer surface of the supergravity high-temperature reactor (4); a heating system (12) is arranged between the heat preservation system (13) and the high-gravity high-temperature reactor (4); the heating system (12) and the hypergravity high-temperature reactor (4) are cavities, and the bottom of the cavity is provided with a liquid outlet (11) for flowing out metal aluminum liquid drops.

9. The plant according to claim 8, characterized by further comprising a slag collection tank (7) and a liquid collection tank (9), the slag collection tank (7) being used for collecting the slag flowing out of the slag outlet (6); the liquid collecting tank (9) is used for collecting the metal aluminum liquid drops flowing out of the liquid outlet (11).

10. The apparatus according to claim 8, characterized in that a thermo thermocouple (3) is arranged in the heating system (12).