CN106861581B - Device for recovering nitrogen from aluminum ash - Google Patents

Abstract

The application discloses device for recovering nitrogen elements in aluminum ash, which comprises a reaction kettle and an absorption tower, wherein the reaction kettle is communicated with the absorption tower through a pipeline for collecting ammonia.

Description

Device for recovering nitrogen from aluminum ash

technical field

The present disclosure generally relates to a device for recovering nitrogen, and more particularly, to a device for recovering nitrogen from aluminum ash slag.

Background technique

Aluminum ash slag (aluminum ash/aluminum slag) is a common waste in the aluminum industry with huge output. Its main sources are infusible inclusions, oxides, additives and Reaction products produced by physical and chemical reactions with additives, etc., are produced in all production processes in which aluminum is melted.

In the process of aluminum smelting, nitrogen is usually charged into the furnace to accelerate purification and purification. Part of the nitrogen is absorbed by the aluminum slag floating on the surface of the aluminum water during evaporation, so the aluminum slag contains nitrogen; and aluminum nitride is formed when it encounters water. Ammonia gas is volatile when heated, so the aluminum ash slag will have a strong irritating ammonia smell when wet, which has brought great trouble to environmental stability and personnel health for a long time.

At present, there are many utilization methods for nitrogen in aluminum ash slag, which basically stay at the theoretical level, and there are very few recycling devices for nitrogen in aluminum ash slag. It is urgent to provide a method for recovering nitrogen in aluminum ash slag device.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a device for recovering nitrogen elements in aluminum ash slag, so as to maximize the recovery of nitrogen elements in aluminum ash slag and avoid post-processing of aluminum ash slag (aluminum slag). The process of pollution to the environment, to achieve harmless, resourceful and efficient aluminum ash slag treatment.

A device for recovering nitrogen in aluminum ash slag provided by the present invention comprises a reaction kettle and an absorption tower, and the reaction kettle and the absorption tower are communicated through a pipeline for collecting ammonia gas.

Compared with the prior art, the device for recovering nitrogen in aluminum ash slag provided by the present application is used for mixing aluminum ash slag with water to form slurry, performing hydrolysis reaction, generating ammonia gas and transferring it to an absorption tower through a pipeline, Then extract nitrogen. The device provided by the invention can efficiently and quickly recover the nitrogen in the aluminum ash slag, make full use of the neglected nitrogen element in the aluminum ash slag for a long time, and at the same time can effectively solve the irritating smell that occurs in the recycling and utilization of the aluminum ash slag problems, greatly improving the working environment and ensuring the life and health of operators.

Description of drawings

Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 is the structural representation of the device for reclaiming nitrogen element in aluminium ash slag provided by the present invention;

2 is a schematic structural diagram of a first housing in the device for recovering nitrogen in aluminum ash slag provided by the present invention;

3 is a perspective view of the first shell in the device for recovering nitrogen in aluminum ash slag provided by the present invention;

4 is a schematic diagram of the connection structure of the stirring shaft and the motor in the device for recovering nitrogen in aluminum ash slag provided by the present invention;

FIG. 5 is a schematic structural diagram of a filtering device in the device for recovering nitrogen in aluminum ash slag provided by the present invention.

Detailed ways

The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the related invention, but not to limit the invention. In addition, it should be noted that, for the convenience of description, only the parts related to the invention are shown in the drawings.

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

As shown in Figures 1 to 5, a device for recovering nitrogen elements in aluminum ash slag provided by the present application includes: a reaction kettle 1 and an absorption tower 2, and the passage between the reaction kettle 1 and the absorption tower 2 is used for collecting The pipeline 3 of ammonia gas is connected.

Further, the reaction kettle 1 includes a reaction kettle shell, a stirring shaft 5 is installed horizontally in the reaction kettle shell, and the stirring shaft 5 is connected with the motor 4 located outside the reactor shell, and a stirring blade 6 is installed outside the stirring shaft 5 .

As shown in FIG. 4 , the stirring shaft 5 and the reactor shell are connected by ball bearings 10 . The stirring shaft 5 is rotatably connected with the reactor shell, and aluminum ash can be poured into the chamber of the reactor through the first through hole 111 and water is added to form a slurry; due to the rotating connection between the reactor shell and the stirring shaft , after the reaction of the slurry in the reactor is complete, rotate the shell of the reactor so that the first through hole is located below, and the first through hole can be used as a discharge port to pour out the mixture. In the present application, the first through hole on the shell of the reactor integrates the functions of the material inlet, the water inlet and the material outlet, which greatly simplifies the structure of the device.

Gear transmission between the stirring shaft 5 and the motor 4, one end of the stirring shaft 5 extends out of the reactor shell and the end is equipped with a first gear; one end of the stirring shaft 5 is connected to a connecting end and extends out of the reactor shell, and is connected A first gear is installed at the end. As shown in FIG. 4 , a second gear 41 is installed on one end of the motor shaft of the first motor 4, the first gear 51 and the second gear 41 are meshed with each other, the stirring shaft rotates under the driving of the motor, and the rotation speed of the stirring shaft is preferably 5r/min～30r/min, easy to stir the slurry evenly and volatilize ammonia gas efficiently.

Further, the reactor shell includes a first shell 11 and a second shell 12 connected by flanges. The flange connection surface between the first shell 11 and the second shell 12 is a first plane, and the first shell 11 and the second shell 12 are connected by flanges. The planes are distributed along the vertical direction, the first through hole 111 and the air outlet 112 are arranged above the first housing, and the air outlet 112 is connected with the pipe 3 .

Further, the first shell 11 and the second shell 12 are both hemispherical structures; the inner wall of the first shell and the inner wall of the second shell are provided with a plurality of raised baffles 7, and the baffles 7 Deviating from the plane passed by the horizontal axis of the reactor shell. In the present application, the shell of the reactor is of spherical structure, and the stirring shaft is located on the horizontal axis of the shell of the reactor; by setting the baffle, the slurry formed by mixing the aluminum ash slag and water is partially stirred during the stirring process. It falls into the baffle and slides along the baffle under the action of gravity. Compared with the case where only the blades rotate, the casting stroke and the external residence time of the material body are increased to a certain extent, so that the reaction of the slurry is more sufficient, and the material The liquid is mixed more uniformly, and the stirring efficiency is higher; at the same time, the process of gas release is accelerated, so that the ammonia gas generated by the reaction can be taken out more quickly.

Further, the baffles on the inner wall of the first casing and the baffles on the inner wall of the second casing are symmetrically distributed with respect to the first plane; the baffles on the inner wall of the first casing are evenly distributed.

Further, on the inner wall of the first housing, the baffle plate extends from the side away from the first plane to the side where the first plane is located, and the baffle plate and the first plane are at an angle of 30°˜60°. As shown in FIG. 3 , taking a baffle 7a as an example, the angle α between the first plane I and the plane II where the baffle is located is 30°˜60°. This setting ensures that the slurry can stay on the baffle for a period of time while the stirring shaft is stirring the slurry.

Further, the device for recovering nitrogen in the aluminum ash slag also includes a bracket 20, and the reactor shell is arranged on the bracket; under the reactor shell and in the direction of the first plane, the bracket is provided with a groove portion. , the flange connecting part of the first shell and the second shell is fitted with the groove part; in the direction perpendicular to the first plane, the flange connecting part is provided with a first circular hole, and the groove part is provided with a first circular hole. There is a second round hole, and the first round hole and the second round hole are connected by a plug 21 . The bracket includes two support ears, and the two support ears are respectively provided with round holes. The stirring shaft and the round holes are connected by rolling bearings. When the aluminum ash slag in the reaction kettle reacts with water, the plug 21 is inserted, and the first through hole 111 is inserted. It is located above the first shell; after the reaction, the plug 21 is pulled out, the reactor shell is turned over 180°, and the slurry is poured out through the first through hole 111 . In the width direction perpendicular to the first plane, the positions of the first through holes 111 and the air outlet holes 112 are staggered from the positions of the grooves. When the reactor shell is turned over by 180°, the first through holes 111 and the air outlet holes 112 and the The grooves do not affect each other. The motor parts are supported by corresponding supports, not shown in the figures.

Further, a filter device is also provided on the pipeline, the filter device includes a first filter device for filtering aluminum ash particles, and the filter device further includes a second filter device for filtering water vapor.

In the present application, the first filter device 8 and the second filter device 9 are arranged on the pipeline 3 in sequence.

Further, the first filter device 8 includes a cylindrical first filter element 81 and a first hard filter screen 82 located on both sides of the first filter element. The first filter element includes a filter body structure formed by winding filter cotton. Evenly distributed activated carbon particles;

The pipe is provided with a first protruding portion 31 , the two first hard filter meshes 82 are engaged with both ends of the inner wall of the first protruding portion 31 , and the first filter element 81 is in seamless contact with the inner wall of the first protruding portion 31 . and is supported in the middle of the two first rigid filter screens 82 .

Further, the second filter device 9 includes a second filter element 91 with a cylindrical structure and a second hard filter screen 92 located on both sides of the second filter element. The composition of the second filter element includes at least one of the following: quicklime, sodium hydroxide and Silica gel;

The pipe is provided with a second protruding portion 32 , the two second hard filter meshes 92 are engaged with both ends of the inner wall of the second protruding portion 32 , and the second filter element 91 is in seamless contact with the inner wall of the second protruding portion 32 . And it is supported in the middle of the two second hard filter screens 92 .

The working principle of the device for collecting nitrogen in aluminum ash slag provided by this application is:

The aluminum ash slag is poured into the chamber of the reaction kettle from the first through hole 111, and through the first through hole 111, a Hot water is used to form slurry, wherein the mass ratio of aluminum ash slag to water is 1:1 to 1:3, then the feeding port is closed, and the motor 4 is turned on to drive the stirring blade 6 on the stirring shaft 5 to rotate, and the stirring blade 6 drives the slurry When the material moves, part of the slurry falls on the baffle and slides along the baffle under the action of gravity, increasing the casting stroke and the external residence time of the material to fully stir the slurry. Nitrogen in aluminum slag usually exists in the form of AlN, and the following reaction occurs when it encounters water: AlN+3H ₂ O=Al(OH) ₃ +NH ₃ , that is, after NH ₃ is generated, it is separated from the slurry and reaches the filter device through the pipeline for The solid particles and water vapor are filtered to obtain purer gas, which is finally absorbed into ammonium salt by strong acid in the absorption tower, and then the shell of the reactor is rotated to pour out the reacted slurry from the first through hole 111 .

The above description is only a preferred embodiment of the present application and an illustration of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solution formed by the specific combination of the above-mentioned technical features, and should also cover the above-mentioned technical features without departing from the inventive concept. Other technical solutions formed by any combination of its equivalent features. For example, a technical solution is formed by replacing the above-mentioned features with the technical features disclosed in this application (but not limited to) with similar functions.

Claims (8)

1. a device for reclaiming nitrogen in the aluminum ash slag, is characterized in that, comprises: reaction kettle and absorption tower, between described reaction kettle and described absorption tower, is communicated by the pipeline for collecting ammonia, so The above-mentioned pipeline is also provided with a filter device; The filter device includes a first filter device for filtering aluminum ash particles, the first filter device includes a cylindrical first filter element and a first hard filter screen located on both sides of the first filter element. A filter element includes a filter body structure composed of filter cotton wound, and activated carbon particles are evenly distributed in the filter body structure; The pipe is provided with a first protruding part, the two first hard filter meshes are clamped at both ends of the inner wall of the first protruding part, and the first filter element and the first protruding part are separated from each other. The inner wall is in seamless contact with and supported in the middle of the two first rigid filter screens. 2. The device for recovering nitrogen in aluminum ash slag according to claim 1, wherein the reactor comprises a reactor shell, and a stirring shaft is installed horizontally in the reactor shell and the stirring The shaft is connected with a motor located outside the reactor shell, and a stirring blade is installed on the outside of the stirring shaft. 3. The device for recovering nitrogen in aluminum ash slag according to claim 2, wherein the reactor shell comprises a first shell and a second shell connected by flanges, and the first shell and the second shell are connected by flanges. The flange connection surface between a casing and the second casing is a first plane, the first plane is distributed along the vertical direction, and a first through hole and an air outlet hole are arranged above the first casing , the air outlet is connected with the pipeline. 4. The device for recovering nitrogen in aluminum ash slag according to claim 3, wherein the first shell and the second shell are hemispherical structures; the first shell The inner wall of the reactor and the inner wall of the second shell are provided with a plurality of raised baffles, and the baffles deviate from the plane passed by the horizontal axis of the reactor shell. 5. The device for recovering nitrogen in aluminum ash slag according to claim 4, wherein the baffles on the inner wall of the first shell and the baffles on the inner wall of the second shell The flow plates are symmetrically distributed with respect to the first plane; the baffle plates on the inner wall of the first shell are evenly distributed. 6 . The device for recovering nitrogen in aluminum ash slag according to claim 5 , wherein, on the inner wall of the first shell, the baffle plate is separated from the end away from the first plane. 7 . Extending to the side where the first plane is located, the baffle plate and the first plane are at a distance of 30°˜60°. 7. The device for recovering nitrogen in aluminum ash slag according to claim 3, characterized in that, further comprising a support, and the reactor shell is arranged on the support; Below the reactor shell and in the direction of the first plane, the bracket is provided with a groove portion, and the flange connection portion of the first shell and the second shell is connected to the The grooves are fitted together; In the direction perpendicular to the first plane, the flange connecting part is provided with a first circular hole, the groove part is provided with a second circular hole, the first circular hole and the second circular hole are The holes are connected by pins. 8. The device for recovering nitrogen in aluminum ash residue according to any one of claims 1-7, wherein the filtering device comprises a second filtering device for filtering water vapor, the second filtering The device comprises a cylindrical second filter element and a second hard filter screen located on both sides of the second filter element, and the second filter element comprises at least one of the following components: quicklime, sodium hydroxide and silica gel; The pipe is provided with a second protruding part, the two second hard filter meshes are clamped at both ends of the inner wall of the second protruding part, and the second filter element and the second protruding part are separated from each other. The inner wall is in seamless contact with and supported in the middle of the two second rigid filter screens.

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