Secondary aluminum dross treatment process

Abstract

The application discloses a secondary aluminum ash treatment process using a secondary aluminum ash treatment device, and relates to the technical field of solid waste treatment. The device comprises a first reactor and a second reactor connected with each other, the first reactor and the second reactor are both connected with a medicament tank and a spraying tower, the first reactor is connected with a gas storage tank through a first spraying tower, the second reactor is connected to a chimney through a second spraying tower, the first spraying tower is connected with a liquid storage tank through a conveying pump, and the second reactor is connected with a crusher through a closed conveying belt or a tunnel type dryer. The application can solve the technical problems in the prior art, such as simple and extensive secondary aluminum ash treatment method, water consumption, low efficiency, high energy consumption, waste gas and waste residue generation, and inability to be resourcefully utilized, and has the advantages of harmless aluminum ash, adaptation to different types of aluminum ash, and higher process added value.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, specifically to secondary aluminum ash treatment and resource recovery production processes and equipment. Background Technology

[0002] Secondary aluminum ash includes secondary aluminum ash collected by bag filters and aluminum ash slag. Secondary aluminum ash is the residue produced after primary aluminum ash undergoes aluminum resource extraction and recovery, and aluminum smelting with salt. It mainly consists of aluminum, aluminum oxides, nitrides, molten salts, and other substances. Secondary aluminum ash varies depending on the region and source; its aluminum content, aluminum nitride content, and the content of other compounds all differ. The aluminum content of secondary aluminum ash is typically between 10% and 20%.

[0003] Aluminum ash possesses the dual characteristics of resource waste and environmental harm. The harmful components in aluminum ash are mainly fluorides, chlorides, and nitrides. The large amount of aluminum nitride in aluminum ash exhibits typical high permeability and high reactivity, reacting with water at room temperature to generate toxic, harmful, and strongly irritating gases, which not only affect human health but also cause air pollution. Chlorides, fluorides, and heavy metals in aluminum ash have a certain degree of leaching toxicity; these harmful elements entering the soil can easily cause soil salinization and groundwater pollution. The extremely fine particle size of aluminum ash easily generates dust during storage, transportation, and processing, causing dust pollution.

[0004] Landfilling is the traditional method for treating aluminum ash. Statistics show that over 90% of secondary aluminum ash is directly stockpiled or landfilled without further treatment. Some is treated using methods such as washing and melting. Landfilling is a low-cost, technically demanding, and traditional extensive method that fails to address the root cause of the problem. Washing is inefficient, requiring significant time for a single process, and the amount of secondary aluminum ash that can be processed is limited. Furthermore, washing consumes a large amount of water, and the treatment of the wastewater after washing typically consumes substantial energy. Melting requires coking coal, which is scarce in some countries and regions, and the coking process generates significant pollution. Even using clean energy sources results in relatively high production costs. Current technologies do not achieve effective treatment and reuse of secondary aluminum ash, failing to form a complete process and ecological chain. The treatment process still generates large amounts of waste gas and residue, which have low resource utilization rates and do not generate added value. Summary of the Invention

[0005] To address the technical problems of existing secondary aluminum ash treatment methods, such as being simple and crude, water-intensive and inefficient, energy-intensive, generating waste gas and slag, and not being able to be utilized as resources, this invention provides a secondary aluminum ash treatment and resource utilization production process and equipment, which can achieve the harmless treatment of aluminum ash, collect gas and ammonia water for reuse, and has a higher added value.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: a secondary aluminum ash treatment equipment, including a first reactor and a second reactor connected to each other. Both the first reactor and the second reactor are connected to a reagent tank and a spray tower. The first reactor is connected to a gas storage tank through a first spray tower. The second reactor is connected to a chimney through a second spray tower. The first spray tower is connected to a liquid storage tank through a conveying pump. The second reactor is connected to a crusher through a closed conveyor belt or a tunnel dryer.

[0007] Optionally, the first reactor and the second reactor are connected by a closed conveyor belt, and there is at least one gas storage tank.

[0008] Optionally, both the first reactor and the second reactor are provided with cooling water channels, the closed conveyor belt is provided with heat dissipation pipes communicating with the cooling water channels, and there is at least one liquid storage tank.

[0009] Optionally, a cooling heat exchanger is provided on the pipe connecting the first reactor and the first spray tower, and the cooling heat exchanger is connected to the heat dissipation pipe of the closed conveyor belt.

[0010] Optionally, both the first reactor and the second reactor are twin-helix reactors. The twin-helix reactor is equipped with a horizontally installed screw or impeller shaft, which is driven by a motor. The upper part of the twin-helix reactor is provided with an air outlet, which is connected to the first spray tower. The first reactor is connected to a feeder.

[0011] Optionally, both the first reactor and the second reactor are vertical stirred reactors with frame-type stirring paddles inside, the cooling water channel is a jacket, and the first reactor is connected to a feeder.

[0012] Optionally, the gas storage tank is connected to a gas generator set or a gas treatment device, the first spray tower includes spray tower one and spray tower two connected in series, and the second spray tower includes spray tower three and spray tower four connected in series.

[0013] The present invention also provides a secondary aluminum ash treatment process, using the aforementioned secondary aluminum ash treatment equipment, including opening the cooling water channel of the first reactor for cooling water supply, simultaneously supplying secondary aluminum ash and liquid alkali agent into the first reactor, opening the first spray tower and the second spray tower, the gas generated from the first reactor entering the first spray tower, the gas entering the gas storage tank after being purified by the first spray tower, the material discharged from the first reactor after reacting for a certain period of time being conveyed into the second reactor by a closed conveyor belt, and a catalyst being added to the second reactor at the same time, the gas generated from the second reactor entering the second spray tower, and the material discharged from the second reactor being conveyed to the crusher by a closed conveyor belt for crushing.

[0014] Optionally, the method also includes sending the liquid in the first spray tower to a liquid storage tank.

[0015] Optionally, the material discharged from the second reactor may be heated and dried in a closed conveyor belt or tunnel dryer, and the cooling water passing through the first and second reactors may be sent to the heat dissipation pipes of the closed conveyor belt.

[0016] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0017] (1) Liquid alkali agent can effectively consume aluminum nitride in secondary aluminum ash. The aluminum nitride in the treated secondary aluminum ash is greatly reduced. The secondary aluminum ash no longer has high activity and presents a stable state. It no longer reacts when it comes into contact with water and can meet the national building material environmental protection standards.

[0018] (2) Effectively reduces the content of chloride and chloride ions in secondary aluminum ash. The treated secondary aluminum ash contains a certain amount of sodium aluminate. Therefore, the treated secondary aluminum ash has high strength and is a good aggregate that can be used to make wall panels and non-fired bricks and other building materials.

[0019] (3) A large amount of combustible gases are generated during the secondary aluminum ash treatment process: ammonia, hydrogen and methane. Ammonia is absorbed by the spray tower to form ammonia water. The ammonia water produced can be used for desulfurization and denitrification, and can also be used for alkali production. Then hydrogen and methane are collected and then utilized for resource utilization. It can be output as industrial fuel.

[0020] (4) A reactor suitable for slurry material reaction is adopted, which has higher processing efficiency and is suitable for different types of aluminum ash or secondary aluminum ash. The secondary aluminum ash after processing is transported by a closed conveyor belt, with no gas leakage. The process is safe, environmentally friendly and pollution-free.

[0021] To make the above-mentioned objects, features and advantages of the present invention easier to understand, some preferred embodiments are provided and described in detail below. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the secondary aluminum ash treatment equipment proposed in an embodiment of the present invention.

[0023] Attached reference numerals: 1. No. 1 reagent tank; 2. First reactor; 3. No. 2 reagent tank; 4. Second reactor; 5. Crusher; 6. Aluminum ash slag storage silo; 7. No. 1 liquid storage tank; 8. No. 2 liquid storage tank; 9. Spray tower one; 10. Spray tower two; 11. Gas storage tank; 12. Spray tower three; 13. Spray tower four; 14. Chimney; 15. Gas generator set; 16. Gas treatment equipment. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection, or a connection between the internal components of two elements; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the terms can be understood according to the specific circumstances.

[0026] This invention discloses a secondary aluminum ash treatment device, such as... Figure 1 As shown, the system includes a first reactor and a second reactor connected to each other. Both reactors are connected to reagent tanks and spray towers. The reagent tanks are designated as Reagent Tank No. 1 and Reagent Tank No. 2, each containing different reagents. The first reactor is connected to a gas storage tank (a domed vertical tank) via a first spray tower; there is at least one gas storage tank. The second reactor is connected to a chimney via a second spray tower. The first spray tower is connected to two liquid storage tanks via a transfer pump: Liquid Storage Tank No. 1 and Liquid Storage Tank No. 2. The second reactor is connected to a crusher via a closed conveyor belt or a tunnel dryer. The crusher is connected to an aluminum ash slag storage silo via a conveyor belt, where the aluminum ash slag is packaged and ready for use. The first and second reactors are connected by a closed conveyor belt. A gas pipeline connecting the first reactor and the first spray tower passes through this closed conveyor belt and is equipped with heat dissipation fins. Since the secondary aluminum ash releases heat during its reaction with liquid alkali, and the gas temperature in the gas pipeline is relatively high, this heat can be used to heat the material being conveyed in the closed conveyor belt, achieving the effects of energy saving and drying the material.

[0027] Both the first and second reactors are equipped with cooling water channels, and the enclosed conveyor belt is equipped with heat dissipation pipes that communicate with the cooling water channels. A cooling heat exchanger is installed on the pipe connecting the first reactor and the first spray tower, and the cooling heat exchanger is connected to the heat dissipation pipes of the enclosed conveyor belt.

[0028] In one embodiment, both the first reactor and the second reactor are vertical stirred reactors, each equipped with a frame-type stirring paddle driven by a motor. The cooling water channels on the first reactor and the second reactor are jacketed. The first reactor is connected to a feeder, and both the first reactor and the second reactor are equipped with pressure relief valves.

[0029] In another embodiment, both the first reactor and the second reactor are double-helix reactors. The double-helix reactor is equipped with a horizontally installed screw or blade shaft, which is driven by an explosion-proof motor. The upper part of the double-helix reactor is equipped with an air outlet, and a pressure relief valve is also provided on the air outlet. The air outlet is connected to the first spray tower, and the first reactor is connected to a feeding machine.

[0030] The gas storage tank is connected to a gas generator set or gas treatment equipment. The first spray tower includes spray tower one and spray tower two connected in series. Both spray tower one and spray tower two are equipped with pressure relief valves. Ammonia concentration detectors are installed at the bottom of both spray tower one and spray tower two. When the ammonia concentration reaches the threshold, a branch line is opened to send ammonia to the liquid storage tank. The spray tower's delivery pump is connected to the liquid inlet at the top of the spray tower and is also connected to the liquid storage tank. When the liquid level in the spray tower drops to the preset level, industrial water is added to the spray tower. The second spray tower includes spray tower three and spray tower four connected in series. The exhaust port of spray tower four is equipped with a gas concentration detector to monitor the composition of the emitted gas in real time to ensure compliance with emission standards. If the standard is exceeded, an alarm is sent to the equipment operation control panel.

[0031] This invention also provides a secondary aluminum ash treatment process using the aforementioned secondary aluminum ash treatment equipment. This includes opening the cooling water channel of the first reactor to supply cooling water, simultaneously supplying secondary aluminum ash and liquid alkali agent into the first reactor. The main components of the liquid alkali agent are sodium hydroxide solution or caustic soda solution. The liquid agent can be piped into the reactor. The first and second spray towers are activated. Gas generated from the first reactor enters the first spray tower, and after purification treatment, it enters a gas storage tank. After reacting in the first reactor for a certain period, the discharged material is conveyed to the second reactor by a closed conveyor belt. Simultaneously, a catalyst is added to the second reactor; the catalyst is one or more of sulfuric acid, calcium carbonate, or sodium carbonate. Gas generated in the second reactor enters the second spray tower, and the discharged material from the second reactor is conveyed to a crusher by a closed conveyor belt for crushing. When the liquid concentration in the first spray tower reaches a threshold, the liquid in the first spray tower is automatically sent to the liquid storage tank. When the gas concentration at the exhaust port of the second spray tower exceeds the standard, the gas generated in the second reactor is sent to an emergency water tank, and the feeding operation of the first reactor is suspended.

[0032] The material discharged from the second reactor is heated and dried in a closed conveyor belt or tunnel dryer. The cooling water from the first and second reactors is sent to the heat dissipation pipes of the closed conveyor belt. This reduces the moisture content of the treated secondary aluminum ash before it enters the crusher. Simultaneously, the heat of reaction generated during the secondary aluminum ash treatment is utilized. The gas produced in the first reactor is cooled before entering the spray tower, improving the absorption effect of the gas in the spray tower.

[0033] The present invention and its embodiments have been described above illustratively, and this description is not restrictive. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A secondary aluminum ash treatment process, characterized in that, It is carried out using secondary aluminum ash treatment equipment. The secondary aluminum ash treatment equipment includes a first reactor and a second reactor connected to each other. Both the first reactor and the second reactor are connected to a reagent tank and a spray tower. The first reactor is connected to a gas storage tank through the first spray tower. The second reactor is connected to a chimney through the second spray tower. The first spray tower is connected to a liquid storage tank through a delivery pump. The second reactor is connected to a crusher through a second closed conveyor belt. The first reactor and the second reactor are connected by a first closed conveyor belt, and there is at least one gas storage tank; The first and second reactors are equipped with cooling water channels, the second closed conveyor belt is equipped with heat dissipation pipes connected to the cooling water channels, and there is at least one liquid storage tank. A cooling heat exchanger is provided on the pipe connecting the first reactor and the first spray tower, and the cooling heat exchanger is connected to the heat dissipation pipe of the second closed conveyor belt. Both the first reactor and the second reactor are double-helix reactors. The double-helix reactor is equipped with a horizontally installed screw or blade shaft, which is driven by a motor. The upper part of the double-helix reactor is equipped with an air outlet. The air outlet of the first reactor is connected to the first spray tower, and the air outlet of the second reactor is connected to the second spray tower. The first reactor is connected to a feeder. The gas storage tank is connected to a gas generator set or gas treatment equipment. The first spray tower includes a spray tower one and a spray tower two connected in series. Both spray tower one and spray tower two are equipped with ammonia concentration detection at the bottom. When the ammonia concentration reaches the threshold, the branch line is opened to send ammonia to the liquid storage tank. The delivery pump of the spray tower is connected to the liquid inlet at the top of the spray tower. The process includes opening the cooling water channel of the first reactor for cooling water supply, simultaneously supplying secondary aluminum ash and liquid alkali agent into the first reactor, opening the first and second spray towers, allowing gas generated from the first reactor to enter the first spray tower, and after purification treatment in the first spray tower, the gas enters the gas storage tank. After reacting in the first reactor for a certain period of time, the discharged material is sent to the second reactor by the first closed conveyor belt, while a catalyst is added to the second reactor. The gas generated in the second reactor enters the second spray tower, and the material discharged from the second reactor is sent to the crusher for crushing by the second closed conveyor belt.

2. The secondary aluminum ash treatment process according to claim 1, characterized in that, The delivery pump is connected to the liquid storage tank.

3. The secondary aluminum ash treatment process according to claim 1, characterized in that, The second spray tower includes spray tower three and spray tower four connected in series.

4. The secondary aluminum ash treatment process according to claim 1, characterized in that, The exhaust port of spray tower four is equipped with a gas concentration detector to monitor the composition of the emitted gas.

5. The secondary aluminum ash treatment process according to claim 1, characterized in that, The motor is an explosion-proof motor.

6. The secondary aluminum ash treatment process according to claim 1, characterized in that, It also includes heating and drying the material discharged from the second reactor in a second closed conveyor belt, and sending the cooling water from the first and second reactors to the heat dissipation pipes of the second closed conveyor belt.

7. The secondary aluminum ash treatment process according to claim 1, characterized in that, Both the first and second reactors are equipped with pressure relief valves.

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