Resource extraction system for returning aluminum ash to aluminum smelting production process

Abstract

The utility model provides a resource extraction system for returning aluminum ash to an aluminum smelting production process, and relates to the technical field of waste resource utilization. Comprising a wet byproduct carbon alkali storage tank, an aluminum electrolysis waste heat exchanger, a dry byproduct carbon alkali storage tank, an aluminum ash storage bin, a calcium additive storage bin, a mixing and stirring bin, a dry pelletizer, a rotary kiln, a dissolution device, a solid-liquid separator, a sodium aluminate storage tank and a tailing solid material storage bin. The system disclosed by the utility model can solve the problem that deep denitrification is difficult in the conventional aluminum ash wet process, and the removal rate of aluminum nitride is improved; the problem that wastewater generated in a current wet treatment process is difficult to treat is solved. The solid regenerated aluminum oxide raw material is directly prepared and returned to the aluminum oxide production process, the problem that the byproduct carbon alkali in the existing Bayer process production evaporation process cannot be economically utilized is solved, the byproduct carbon alkali serves as the raw material to be subjected to synergistic reaction with the aluminum ash, organic matter in the byproduct carbon alkali is eliminated, aluminum and sodium resources are efficiently extracted, and green cyclic utilization of the resources is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to waste resource utilization technical field, especially point to a kind of resource extraction system of aluminium dross returns aluminium smelting production process. BACKGROUND

[0002] Aluminium dross is solid waste generated in the production process of aluminium smelting industry, which contains toxic and harmful components such as aluminium nitride and fluoride salt, and will release irritating ammonia when exposed to the open air. On the other hand, aluminium dross also contains a large amount of alumina (60-70%), which is a valuable resource. Therefore, it is urgent to develop green and clean safe disposal and resource utilization technology to remove toxic substances and extract valuable alumina resources.

[0003] By-product carbon alkali is a by-product produced in the evaporation process of alumina production process, and the main components are sodium carbonate, sodium hydroxide, alumina and organic matter. The reason for the production of by-product carbon alkali is that: carbon dioxide in the air or insufficiently calcined lime will introduce carbonate into the Bayer process of alumina production, causing the sodium carbonate content of the system to increase, which is not conducive to the normal production and index control of the Bayer process. Therefore, it is necessary to evaporate and crystallize the sodium carbonate enriched to a certain concentration in the evaporation process to reduce the carbon alkali concentration in the circulating system. At present, by-product carbon alkali is difficult to be directly returned to the alumina production process for reuse due to its complex composition and the presence of organic matter, resulting in waste of alkali resources.

[0004] The prior art scheme mostly uses wet process to treat industrial waste containing alumina, although ammonia gas can be absorbed and treated, but due to the slow hydrolysis rate of aluminium nitride and the need for additional heat source, the ammonia water concentration produced is low and cannot be directly used as a product for sale. Or the process flow is complex, and the process products are difficult to recycle. UTILITY MODEL CONTENT

[0005] At present, the process technology for extracting alumina from aluminium dross mostly has the problems of low alumina extraction rate, complex process flow and high economic cost. In view of the defects and deficiencies of the prior art, the utility model provides a resource extraction system for aluminium dross returning to aluminium smelting production process, which uses by-product carbon alkali discharged by Bayer process as the main reaction aid, and generates regenerated alumina raw material which is easily soluble in alkali liquor under the action of calcium additive through precise proportioning and directional reaction. Specifically:

[0006] A resource extraction system for aluminium dross returning to aluminium smelting production process, comprising:

[0007] Wet by-product carbon alkali storage tank, aluminium electrolysis waste heat exchanger, dry by-product carbon alkali storage tank, aluminium dross storage bin, calcium additive storage bin, mixing and stirring bin, dry balling machine, rotary kiln, leaching device, solid-liquid separator, sodium aluminate storage tank and tailings solid material storage bin;

[0008] The wet by-product carbon alkali storage tank, the aluminum electrolysis waste heat exchanger, and the dry by-product carbon alkali storage tank are sequentially connected in order; the dry by-product carbon alkali storage tank, the aluminum ash storage bin, and the calcium additive storage bin are connected with the feeding port of the mixing and stirring bin; the feeding port of the mixing and stirring bin is connected with the dry balling machine, the rotary kiln, the dissolver, and the solid-liquid separator in order; the liquid phase outlet of the solid-liquid separator is connected with the sodium aluminate storage tank, and the solid phase outlet is connected with the tailing solid material storage bin.

[0009] Preferably, the by-product carbon alkali comes from by-products generated in the evaporation process of the Bayer process for producing alumina.

[0010] Preferably, the dry by-product carbon alkali, the aluminum ash, and the calcium additive are mixed in the mixing and stirring bin.

[0011] Preferably, the sodium aluminate in the sodium aluminate storage tank is used for producing alumina.

[0012] Preferably, the tailing in the tailing solid material storage bin is used for producing building materials.

[0013] The technical scheme provided by the embodiment of the utility model has at least the following beneficial effects:

[0014] The utility model discloses a process for recycling aluminum ash, which comprises the following steps: dissolving aluminum ash to obtain a solution; removing harmful substances in the solution; mixing the solution with by-product carbon alkali to obtain a mixture; mixing the mixture with calcium additive to obtain a mixture; and sintering the mixture to obtain a sintered product. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating labor.

[0016] Figure 1 The flow chart of the utility model;

[0017] 1-wet by-product carbon alkali storage tank; 2-aluminum electrolysis waste heat exchanger; 3-dry by-product carbon alkali storage tank; 4-aluminum ash storage bin; 5-calcium additive storage bin; 6-mixing and stirring bin; 7-dry balling machine; 8-rotary kiln; 9-dissolver; 10-solid-liquid separator; 11-sodium aluminate storage tank; 12-tailing solid material storage bin. DETAILED DESCRIPTION

[0018] The technical solutions in the utility model will be described below with reference to the drawings.

[0019] In the embodiments of the utility model, the words such as "for example", "for example" are used to represent an example, illustration or description. Any embodiment or design scheme described as "example" in the utility model should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the utility model, the meaning expressed by "and / or" can be both, or can be either of the two.

[0020] In the embodiments of the utility model, "image" and "picture" can be used interchangeably sometimes. It should be pointed out that when the distinction is not emphasized, the meanings expressed are consistent. "The", "corresponding" and "corresponding" can be used interchangeably sometimes. It should be pointed out that when the distinction is not emphasized, the meanings expressed are consistent.

[0021] In the embodiments of the utility model, sometimes the subscript such as W1 may be mistakenly used in the form of non-subscript such as W1. When the distinction is not emphasized, the meanings expressed are consistent.

[0022] In order to make the technical problems, technical schemes and advantages to be solved by the utility model more clear, the following will be described in detail with reference to the drawings and specific embodiments.

[0023] As shown in Figure 1 The system comprises a wet by-product carbon alkali storage tank 1, an aluminum electrolysis waste heat exchanger 2, a dry by-product carbon alkali storage tank 3, an aluminum ash storage bin 4, a calcareous additive storage bin 5, a mixing and stirring bin 6, a dry balling machine 7, a rotary kiln 8, a leaching device 9, a solid-liquid separator 10, a sodium aluminate storage tank 11, and a tailing solid material storage bin 12.

[0024] The wet by-product carbon alkali generated by the Bayer process is sent from a wet by-product carbon alkali storage tank 1 to an aluminum electrolysis waste heat exchanger 2 for drying treatment, and the dried dry by-product carbon alkali is sent to a dry by-product carbon alkali storage tank 3 for storage. The aluminum ash in an aluminum ash storage bin 4, the dry by-product carbon alkali in the dry by-product carbon alkali storage tank 3, and the calcium additive in a calcium additive storage bin 5 are precisely proportioned according to Al2O3, Fe2O3, SiO2, MgO, and F in the aluminum ash, and are added to a mixing and stirring bin 6 in a certain proportion. The mixing and stirring bin 6 sends the uniformly mixed material to a dry balling machine 7. The formed material is sent to a rotary kiln 8 for calcination. The main reactions in the rotary kiln 8 are as follows: the aluminum-containing components in the aluminum ash react with sodium oxide in the by-product carbon alkali to generate sodium aluminate, the harmful substance F in the aluminum ash reacts with the calcium additive to generate harmless and inert calcium fluoride, the harmful substance aluminum nitride reacts to generate sodium aluminate and nitrogen, and the impurities iron, silicon, magnesium, and other oxides in the aluminum ash react with the calcium additive and the by-product carbon alkali to generate insoluble substances.

[0025] The calcination product of the rotary kiln 8 enters a leaching device 9 for leaching. The leaching slurry is subjected to solid-liquid separation in a solid-liquid separator 10, the obtained sodium aluminate solution enters a sodium aluminate storage tank 11, and is subsequently used for seed decomposition to prepare various types of alumina products, and the filter residue enters a tailing solid storage bin 12 and can be used as a raw material for preparing building materials.

[0026] The above is only a specific implementation manner of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A resource extraction system for returning aluminum dross to an aluminum smelting production flow, characterized by, The application relates to a production system of a dry-process method for producing alumina and building materials from bauxite, which comprises the following: a wet by-product carbon alkali storage tank, an aluminum electrolysis waste heat exchanger, a dry by-product carbon alkali storage tank, an aluminum ash storage bin, a calcium additive storage bin, a mixing and stirring bin, a dry balling machine, a rotary kiln, a dissolver, a solid-liquid separator, a sodium aluminate storage tank and a tailing solid material storage bin; the wet by-product carbon alkali storage tank, the aluminum electrolysis waste heat exchanger and the dry by-product carbon alkali storage tank are sequentially connected; the discharge outlets of the dry by-product carbon alkali storage tank, the aluminum ash storage bin and the calcium additive storage bin are connected with the feeding inlet of the mixing and stirring bin; the discharge outlet of the mixing and stirring bin is sequentially connected with the dry balling machine, the rotary kiln, the dissolver and the solid-liquid separator; the liquid phase outlet of the solid-liquid separator is connected with the sodium aluminate storage tank, and the solid phase outlet is connected with the tailing solid material storage bin.

2. The resource extraction system for returning aluminum dross to an aluminum smelting production flow according to claim 1, characterized in that, The by-product carbon alkali comes from by-products generated in an evaporation process of a bayer process production system for producing alumina.

3. The resource extraction system for returning aluminum dross to an aluminum smelting production flow according to claim 1, characterized in that, The sodium aluminate in the sodium aluminate storage tank is used for producing alumina.

4. The resource extraction system for returning aluminum dross to an aluminum smelting production flow according to claim 1, characterized in that, The tailings in the tailing solid material storage bin are used for producing building materials.

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