Waste acid recovery process

Abstract

The invention relates to a waste acid recovery process, and relates to the technical field of waste acid recovery treatment.The waste acid recovery process comprises the following steps that S1, an air outlet and a discharging opening are closed, a heating piece operates, and the temperature in a furnace body is monitored till the temperature in the furnace body rises to a set value; s2, an air outlet is opened, waste acid is atomized and sprayed into the furnace body through a spray gun, a baffle plate is driven to rotate through a driving part, and the quantity of fixed products in the furnace body is monitored; s3, when the amount of the solid product reaches a set value, a discharge port is opened; and S4, after the fixed product is discharged, closing the discharge port. The method has the effect that the situation that the recovery rate of waste acid is affected due to the fact that the waste acid which is not completely reacted and is carried in the fixed product is discharged is avoided.

Description

Technical Field

[0001] The present application relates to the field of waste acid recovery and treatment technology, and in particular to a waste acid recovery process. Background Art

[0002] Hydrochloric acid is often used in industry to clean materials or equipment such as steel. In this process, a large amount of waste hydrochloric acid with a high iron content is produced. These hydrochloric acids have high iron content and low concentration, lacking industrial application value, and directly discharged as wastewater will cause serious pollution. However, through simple treatment procedures, these waste acids can be treated under relatively mild conditions to obtain industrial-grade concentrated hydrochloric acid with greater commercial value, which can be recycled and reused.

[0003] Existing waste acid recovery processes generally include spray roasting and fluidized bed roasting. When waste hydrochloric acid is regenerated by spray roasting, the waste hydrochloric acid needs to be sprayed into a roasting furnace through a spray gun for heating reaction. The heating reaction generates solid product iron powder and gaseous product concentrated hydrochloric acid. The solid product falls to the bottom of the roasting furnace for recovery, and the gaseous product passes through the top of the roasting furnace to subsequent processing steps. After a series of processing, it can be used to regenerate industrial-grade concentrated hydrochloric acid, thereby completing the recovery and reuse of waste hydrochloric acid.

[0004] In actual operation, during the process of recovering waste acid by the above method, after the waste acid is atomized and sprayed into the furnace body through a spray gun, the gaseous product rises and is directly discharged through the outlet. Part of the waste acid will be directly carried out by the gaseous product and cannot be heated and reacted in the roasting furnace, resulting in unsatisfactory waste acid recovery effect, and the recovered concentrated hydrochloric acid will carry more impurities. Summary of the invention

[0005] In order to improve the problem that the waste acid recovery effect in the prior art is not ideal and the recovered concentrated hydrochloric acid carries a lot of impurities, the present application provides a waste acid recovery process.

[0006] A waste acid recovery process provided in this application adopts the following technical solution: A waste acid recovery process, using a waste acid roasting furnace to treat the waste acid, the waste acid roasting furnace comprising a furnace body, the furnace body is provided with a gas outlet and a material outlet, the furnace body is provided with a heating element, the furnace body is provided with a spray gun, a shielding plate is rotatably provided at the gas outlet, the furnace body is provided with a driving part for driving the shielding plate to rotate, and the shielding plate rotates to intermittently shield the gas outlet; The waste acid recovery process comprises the following steps: S1: The gas outlet and the material outlet are closed, the heating element is in operation, and the temperature inside the furnace is monitored until the temperature inside the furnace rises to the set value; S2: The gas outlet is opened, and the waste acid is sprayed into the furnace body by a spray gun, and the shielding plate is driven to rotate by the driving unit to monitor the amount of fixed products in the furnace body; S3: When the amount of solid product reaches the set value, the discharge port is opened; S4: After the fixed product is discharged, the discharge port is closed.

[0007] By adopting the above technical scheme, before the waste acid is introduced into the furnace body for roasting, the heating element is operated first, and the heating element operates to increase the temperature in the furnace body. When the temperature in the furnace body rises to the set value, the air outlet is opened, and the driving part is operated at this time. The operation of the driving part drives the shielding plate to rotate, and the shielding plate rotates to intermittently shield the air outlet. The spray gun atomizes the waste acid and sprays it into the furnace body. The waste acid is heated and reacted in the furnace body to produce solid product iron powder and high-temperature gas product hydrochloric acid vapor. The iron powder falls to the bottom of the furnace body, and the hydrochloric acid vapor is discharged through the air outlet to be reused. In this process, the fixed product in the furnace body is monitored in real time. When the amount of fixed product in the furnace body reaches the set value, the discharge port is opened and the fixed product is discharged through the discharge port.

[0008] When the waste acid is recovered and treated by the above process, with the cooperation of the baffle plate and the driving part, the residence time of the hydrochloric acid vapor in the furnace body is increased, thereby avoiding the direct discharge of the gas product through the gas outlet, so that part of the waste acid does not have time to undergo heating reaction and is taken out, thereby improving the waste acid recovery effect and recovery purity; in addition, before the waste acid is introduced into the furnace body, the heating element is first operated to make the temperature in the furnace body reach a set value, thereby avoiding the waste acid sprayed through the spray gun from failing to undergo rapid heating reaction due to insufficient temperature, so that the rising hydrochloric acid vapor directly takes out this part of the waste acid; and the fixed product in the furnace body is not discharged in real time, but when the set value is reached, the discharge port is opened regularly to discharge the fixed product, thereby increasing the residence time of the fixed product in the furnace body, avoiding the fixed product carrying unreacted waste acid and being discharged, thereby affecting the recovery rate of the waste acid.

[0009] Optionally, the heating element includes a heating plate arranged in the furnace body, the heating plate is provided with a filter hole, the discharge port, the heating plate, the spray gun and the air outlet are arranged in sequence from low to high; a driving shaft is fixed on the rotating shaft of the baffle plate, a cleaning rod is provided on the driving shaft, the cleaning rod is provided with bristles, and the bristles are inserted into the filter hole.

[0010] By adopting the above technical scheme, the iron powder generated by the contact reaction between the waste acid and the heating plate will fall onto the heating plate under the action of gravity, and then fall to the discharge port through the filter hole, and then be discharged through the discharge port, while the hydrochloric acid vapor moves upward due to the heat and is discharged through the air outlet, thereby facilitating the separation of the iron powder and the hydrochloric acid vapor; and in the process of the waste acid being introduced into the furnace body for heating reaction, the driving unit drives the baffle plate to rotate, and the rotation of the baffle plate drives the driving shaft to rotate, thereby the cleaning rod rotates, and the bristles rotate together with the cleaning rod, and the filter holes are cleaned by the bristles to avoid clogging of the filter holes and making it difficult for the fixed product to be discharged through the discharge port.

[0011] Optionally, the heating plate includes a plurality of heating rods, which are staggered to form a mesh structure, and the grids of the mesh structure form the filter holes; an electric heating wire is arranged in each of the heating rods, and a power supply component for supplying power to the electric heating wire is provided on the furnace body.

[0012] By adopting the above technical solution, a plurality of heating rods are staggered to form a mesh structure, and the grids of the mesh structure form filter holes for the iron powder to fall through. Since a heating wire is provided in each heating rod, the power supply supplies power to the heating wire to operate the heating wire, thereby making the heating rod have a high temperature, and the iron powder can be fully heated when passing through the filter hole, thereby preventing the iron powder from carrying unreacted waste acid and falling to the discharge port, which affects the recovery rate of the waste acid.

[0013] Optionally, a rotating ring is rotatably provided on the driving shaft, and a scraping rod is provided on the rotating ring for scraping off particles adhering to the lower surface of the baffle.

[0014] By adopting the above technical solution, when the driving shaft rotates, it is affected by the waste acid and gas products in the furnace body, and the rotating ring and the driving shaft rotate asynchronously. The rotation of the rotating ring drives the scraper rod to rotate, and the scraper rod will clean the lower surface of the baffle plate to prevent the solid product particles produced by the heating reaction of the waste acid from adhering to the baffle plate, which will cause the gas product to be discharged through the outlet, and these solid product particles will be brought out, causing the purity of the recovered gas product to be affected.

[0015] Optionally, a limiting groove is provided on the driving shaft along the circumferential direction, the rotating ring is located in the limiting groove, and a ball in contact with the limiting groove is provided on the inner wall of the rotating ring.

[0016] By adopting the above technical solution, the limit groove is used to ensure the position of the swivel, thereby improving the stability of the swivel during rotation. During the rotation of the swivel, the ball contacts and rolls with the groove wall of the limit groove, thereby improving the flexibility of the swivel during rotation.

[0017] Optionally, the spray gun is arranged to be inclined downward in a direction toward the heating plate.

[0018] By adopting the above technical solution, since the spray gun is tilted toward the heating disk, the waste acid is sprayed directly onto the heating disk through the spray gun, and the waste acid can contact the heating disk in a timely and rapid manner to undergo a heating reaction, thereby improving the efficiency of waste acid recovery.

[0019] Optionally, there are multiple spray guns, and each spray gun tube is provided with an air pressure sensor and a control valve; in step S2, the air pressure in the spray gun tube of the spray gun is monitored by the air pressure sensor, and when the air pressure in the spray gun tube of the spray gun shows an abnormal value, the spray gun tube of the spray gun is controlled to be closed by the control valve.

[0020] By adopting the above technical scheme, waste acid is synchronously transported into the furnace body through multiple spray guns, thereby increasing the amount of waste acid introduced in the same period, and further improving the efficiency of the waste acid recovery operation; and in the whole process of waste acid being sprayed into the furnace body through the spray gun, the air pressure in the spray gun pipe of the corresponding spray gun is monitored by the air pressure sensor. When the air pressure in the spray gun pipe of the spray gun shows an abnormal value, the spray gun pipe of the spray gun is controlled to be closed by the control valve. At this time, other spray guns can still operate normally to avoid reducing the efficiency of the waste acid recovery operation. This setting can prevent fixed product particles from adhering to the nozzle of the spray gun, causing the waste acid to be blocked and accumulated in the spray gun pipe of the spray gun and difficult to discharge, so that the spray gun pipe of the spray gun is continuously fed with waste acid, causing the spray gun pipe of the spray gun to be over-pressurized and damaged.

[0021] Optionally, in step S1, the waste acid is preheated.

[0022] By adopting the above technical solution, the waste acid is preheated during the process of the heating element operating to raise the temperature in the furnace body to the set value, so that the waste acid has a certain temperature. At this time, the waste acid has a certain temperature but has not reached the temperature for generating a heating reaction. Subsequently, the spray gun atomizes the preheated waste acid and sprays it into the furnace body. The waste acid can be quickly heated to the set temperature to generate a heating reaction, thereby improving the efficiency of the waste acid recovery operation.

[0023] Optionally, the waste acid may be subjected to a precipitation treatment before being preheated.

[0024] By adopting the above technical scheme, before the waste acid is preheated so that the waste acid enters the furnace body for heating reaction, the waste acid is first precipitated to remove large particle impurities carried in the waste acid, thereby improving the efficiency of subsequent waste acid recovery operations and avoiding clogging of the spray gun caused by impurities carried in the waste acid.

[0025] Optionally, a sedimentation tank is used to precipitate the waste acid, the sedimentation tank is connected to the spray gun through a pipeline, a filtrate plate is arranged in the sedimentation tank, a liquid inlet is opened on the sedimentation tank, the liquid inlet is located below the filtrate plate, and a liquid outlet is opened on the sedimentation tank, the liquid outlet is located above the filtrate plate.

[0026] By adopting the above technical solution, the waste acid enters the sedimentation tank through the liquid inlet of the sedimentation tank, and the waste acid enters the space above the filtrate plate through the filtrate plate, and then can be transported through the liquid outlet for subsequent processes. However, large particle impurities carried in the waste acid are difficult to pass through the filtrate plate and are located in the space below the filtrate plate, thereby facilitating the removal of large particle impurities carried in the waste acid and preventing the impurities from being transported to the subsequent processes through the liquid outlet, which would affect the precipitation effect of the sedimentation tank on the waste acid.

[0027] In summary, the present application includes at least one of the following beneficial technical effects: 1. With the cooperation of the shielding plate and the driving part, the residence time of the hydrochloric acid vapor in the furnace body is increased, thereby preventing the gas product from being directly discharged through the gas outlet, so that part of the waste acid is not able to undergo heating reaction in time and is taken out, thereby improving the waste acid recovery effect and recovery purity; in addition, before the waste acid is introduced into the furnace body, the heating element is operated first to make the temperature in the furnace body reach the set value, thereby preventing the waste acid sprayed through the spray gun from failing to undergo heating reaction quickly due to insufficient temperature, so that the rising hydrochloric acid vapor directly takes out this part of the waste acid; and the fixed product in the furnace body is not discharged in real time, but when the set value is reached, the discharge port is opened regularly to discharge the fixed product, thereby increasing the residence time of the fixed product in the furnace body, preventing the fixed product from carrying unreacted waste acid and being discharged, thereby affecting the recovery rate of the waste acid; 2. The iron powder generated by the contact reaction between the waste acid and the heating plate will fall onto the heating plate under the action of gravity, then fall to the discharge port through the filter hole, and then be discharged through the discharge port, while the hydrochloric acid vapor moves upward due to the heat and is discharged through the gas outlet, which is beneficial to the separation of the iron powder and the hydrochloric acid vapor; while the waste acid is introduced into the furnace body for heating reaction, the driving unit drives the shielding plate to rotate, and the rotation of the shielding plate drives the driving shaft to rotate, thereby the cleaning rod rotates, and the bristles rotate together with the cleaning rod, and the filter holes are cleaned by the bristles to avoid clogging of the filter holes and making it difficult for the fixed products to be discharged through the discharge port; 3. Waste acid is synchronously transported into the furnace body through multiple spray guns, thereby increasing the amount of waste acid introduced in the same period, and further improving the efficiency of the waste acid recovery operation; and in the whole process of the waste acid being sprayed into the furnace body through the spray gun, the air pressure in the spray gun pipe of the corresponding spray gun is monitored by the air pressure sensor. When the air pressure in the spray gun pipe of the spray gun shows an abnormal value, the spray gun pipe of the spray gun is closed by the control valve. At this time, other spray guns can still operate normally to avoid reducing the efficiency of the waste acid recovery operation. This setting can prevent fixed product particles from adhering to the nozzle of the spray gun, causing the waste acid to be blocked and accumulated in the spray gun pipe of the spray gun and difficult to discharge, so that the spray gun pipe of the spray gun is continuously fed with waste acid, causing the spray gun pipe of the spray gun to be over-pressurized and damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the cooperation between a waste acid roasting furnace, a precipitation tank and a preheating tank used in a waste acid recovery process in an embodiment of the present application; Figure 2 yes Figure 1 A cross-sectional view of Figure 3 is a cross-sectional view of a waste acid roasting furnace used in a waste acid recovery process in an embodiment of the present application; Figure 4 It is a schematic diagram of the cooperation between a shielding plate, a driving shaft, a cleaning rod and a heating plate used in a waste acid recovery process in an embodiment of the present application; Figure 5 yes Figure 3 Enlarged view of part A.

[0029] Explanation of the reference numerals in the accompanying drawings: 1. furnace body; 2. air outlet; 3. discharge port; 4. heating element; 41. heating rod; 42. battery; 5. spray gun; 6. baffle plate; 7. driving unit; 71. driving motor; 8. filter hole; 9. driving shaft; 10. cleaning rod; 11. reinforcing rod; 12. bristles; 13. swivel; 14. scraper rod; 15. limiting groove; 16. ball bearing; 17. main pipe; 18. preheating tank; 19. spiral heating tube; 20. sedimentation tank; 21. filtrate plate; 22. liquid inlet; 23. liquid outlet. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1-5 This application is described in further detail.

[0031] The present application discloses a waste acid recovery process. Figure 1 and Figure 2The waste acid recovery process uses a waste acid roasting furnace to treat the waste acid. The waste acid roasting furnace includes a furnace body 1, which is provided with a gas outlet 2 and a material outlet 3. A heating element 4 is arranged in the furnace body 1, and a spray gun 5 is arranged on the furnace body 1. A baffle plate 6 is rotatably arranged at the gas outlet 2. A driving part 7 for driving the baffle plate 6 to rotate is arranged on the furnace body 1. The baffle plate 6 rotates to intermittently block the gas outlet 2.

[0032] Reference Figure 1 and Figure 3 The heating element 4 includes a heating plate arranged in the furnace body 1, the discharge port 3, the heating plate, the spray gun 5 and the air outlet 2 are arranged in sequence from low to high, the spray gun 5 is arranged downwardly inclined toward the heating plate, the heating plate includes a plurality of heating rods 41, the heating rods 41 are staggered to form a mesh structure, and the grids of the mesh structure form filter holes 8; each heating rod 41 is provided with an electric heating wire, and the furnace body 1 is provided with a power supply component for supplying power to the electric heating wire.

[0033] The spray gun 5 is tilted toward the heating disk, and the waste acid is sprayed directly onto the heating disk through the spray gun 5. The waste acid can contact the heating disk in a timely and rapid manner to undergo a heating reaction. The iron powder generated by the contact reaction between the waste acid and the heating disk will fall onto the heating disk under the action of gravity, and then fall to the discharge port 3 through the filter hole 8, and then be discharged through the discharge port 3, while the hydrochloric acid vapor moves upward due to the heat and is discharged through the air outlet 2, thereby facilitating the separation of the iron powder and the hydrochloric acid vapor; and a plurality of heating rods 41 are staggered to form a mesh structure, and the grids of the mesh structure form the filter hole 8 for the iron powder to fall. Since a heating wire is provided in each heating rod 41, the power supply supplies power to the heating wire to operate the heating wire, thereby making the heating rod 41 have a high temperature, and the iron powder can be fully heated when passing through the filter hole 8.

[0034] In the embodiment of the present application, the power supply is a battery 42 electrically connected to the heating wire.

[0035] Reference Figure 3 and Figure 4 The driving part 7 is selected as a driving motor 71, and the driving motor 71 is installed on the furnace body 1. The output shaft of the driving motor 71 is coaxially fixedly connected with the rotating shaft of the baffle plate 6. A driving shaft 9 is fixed on the rotating shaft of the baffle plate 6. A plurality of cleaning rods 10 are fixed on the driving shaft 9 along the circumferential direction. A reinforcing rod 11 is also fixedly connected between each cleaning rod 10 and the driving shaft 9. Bristles 12 are fixed on each cleaning rod 10, and the bristles 12 are inserted into the filter holes 8.

[0036] During the process of waste acid being introduced into the furnace body 1 for heating reaction, the driving unit 7 drives the baffle plate 6 to rotate, and the rotation of the baffle plate 6 drives the driving shaft 9 to rotate, so that the cleaning rod 10 rotates, and the bristles 12 rotate along with the cleaning rod 10, and the filter holes 8 are cleaned by the bristles 12 to prevent the filter holes 8 from being blocked, which makes it difficult for the fixed product to be discharged through the discharge port 3.

[0037] Reference Figure 4 and Figure 5 A swivel 13 is rotatably provided on the driving shaft 9, and a limiting groove 15 is circumferentially provided on the driving shaft 9. The swivel 13 is located in the limiting groove 15. A ball 16 in contact with the limiting groove 15 is provided on the inner wall of the swivel 13. A scraper rod 14 is fixed to the outer wall of the swivel 13 for scraping off particles adhered to the lower surface of the baffle plate 6.

[0038] When the driving shaft 9 rotates, affected by the waste acid and gas products in the furnace body 1, the rotating ring 13 and the driving shaft 9 rotate asynchronously. During the rotation of the rotating ring 13, the ball 16 contacts and rolls with the groove wall of the limiting groove 15, thereby improving the flexibility of the rotating ring 13 during rotation; the rotation of the rotating ring 13 drives the scraper rod 14 to rotate, and the scraper rod 14 will clean the lower surface of the baffle plate 6 to prevent the solid product particles produced by the heating reaction of the waste acid from adhering to the baffle plate 6, thereby causing the gas product to be discharged through the outlet 2, and these solid product particles will be taken out.

[0039] Reference Figure 1 and Figure 2 There are multiple spray guns 5, and a pressure sensor and a control valve are provided on the spray gun pipe of each spray gun 5. The spray gun pipes of each spray gun 5 are interconnected through a main pipe 17. A preheating tank 18 is provided on one side of the waste acid roasting furnace, and a sedimentation tank 20 is provided on one side of the preheating tank 18.

[0040] Reference Figure 1 and Figure 2 The sedimentation tank 20 is connected with the preheating tank 18 through a pipeline, and the preheating tank 18 is connected with the main pipe 17 through a pipeline. A liquid inlet 22 is opened on the sedimentation tank 20, and the liquid inlet 22 is located below the filtrate plate 21. A liquid outlet 23 is opened on the sedimentation tank 20, and the liquid outlet 23 is located above the filtrate plate 21. A spiral heating tube 19 is arranged in the preheating tank 18 for preheating the waste acid.

[0041] The waste acid recovery process includes the following steps: S1: Waste acid precipitation: The waste acid enters the precipitation tank 20 through the liquid inlet 22 of the precipitation tank 20, and the waste acid enters the space above the filtrate plate 21 through the filtrate plate 21, and the precipitated waste acid is passed into the preheating tank 18 through the liquid outlet 23, and the precipitation tank 20 removes large particle impurities carried in the waste acid; Preheating of waste acid: waste acid enters the preheating tank 18, and the spiral heating tube 19 operates to preheat the waste acid; The furnace body 1 is pre-operated: the gas outlet 2 and the material outlet 3 are closed, the heating element 4 is operated, and the temperature in the furnace body 1 is monitored until the temperature in the furnace body 1 rises to the set value; S2: The gas outlet 2 is opened, and the waste acid is sprayed into the furnace body 1 through the spray gun 5, and the shielding plate 6 is driven to rotate by the driving unit 7 to monitor the amount of fixed products in the furnace body 1; S3: When the amount of solid product reaches the set value, the discharge port 3 is opened; S4: After the fixed product is discharged, the discharge port 3 is closed.

[0042] In the embodiment of the present application, when step S2 is performed, the air pressure in the spray gun tube of the spray gun 5 is monitored by an air pressure sensor. When the air pressure in the spray gun tube of the spray gun 5 reaches an abnormal value, the spray gun tube of the corresponding spray gun 5 is controlled to be closed by a control valve to prevent fixed product particles from adhering to the nozzle of the spray gun 5, causing waste acid to be blocked and accumulated in the spray gun tube of the spray gun 5 and difficult to discharge, so that the spray gun tube of the spray gun 5 is continuously fed with waste acid, causing the spray gun tube of the spray gun 5 to be over-pressurized and damaged.

[0043] The implementation principle of a waste acid recovery process in an embodiment of the present application is as follows: before the waste acid is introduced into the furnace body 1 for roasting, the heating element 4 is operated first, and the heating element 4 is operated to increase the temperature in the furnace body 1. When the temperature in the furnace body 1 rises to a set value, the gas outlet 2 is opened, and the driving unit 7 is operated at this time. The operation of the driving unit 7 drives the baffle plate 6 to rotate, and the baffle plate 6 rotates to intermittently block the gas outlet 2. The spray gun 5 atomizes the waste acid and sprays it into the furnace body 1. The waste acid is heated and reacted in the furnace body 1 to produce a solid product iron powder and a high-temperature gas product hydrochloric acid vapor. The iron powder falls to the bottom of the furnace body 1, and the hydrochloric acid vapor is discharged through the gas outlet 2 for reuse. In this process, the fixed product in the furnace body 1 is monitored in real time. When the amount of the fixed product in the furnace body 1 reaches the set value, the discharge port 3 is opened and the fixed product is discharged through the discharge port 3.

[0044] When the waste acid is recovered by the above process, with the cooperation of the shielding plate 6 and the driving part 7, the residence time of the hydrochloric acid vapor in the furnace body 1 is increased, thereby avoiding the direct discharge of the gas product through the gas outlet 2, so that part of the waste acid is not able to undergo heating reaction in time and is taken out, thereby improving the waste acid recovery effect and recovery purity; in addition, before the waste acid is introduced into the furnace body 1, the heating element 4 is operated first to make the temperature in the furnace body 1 reach the set value, thereby avoiding the waste acid sprayed through the spray gun 5 from failing to undergo heating reaction quickly due to insufficient temperature, so that the rising hydrochloric acid vapor directly takes out this part of the waste acid; and the fixed product in the furnace body 1 is not discharged in real time, but when the set value is reached, the discharge port 3 is opened regularly to discharge the fixed product, thereby increasing the residence time of the fixed product in the furnace body 1, avoiding the fixed product carrying unreacted waste acid and being discharged, thereby affecting the recovery rate of the waste acid.

[0045] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A waste acid recovery process, using a waste acid roasting furnace to treat waste acid, characterized in that: The waste acid roasting furnace comprises a furnace body (1), the furnace body (1) is provided with a gas outlet (2) and a material outlet (3), a heating element (4) is arranged inside the furnace body (1), a spray gun (5) is arranged on the furnace body (1), a shielding plate (6) is rotatably arranged at the gas outlet (2), a driving part (7) is arranged on the furnace body (1) for driving the shielding plate (6) to rotate, and the shielding plate (6) rotates to intermittently shield the gas outlet (2); The waste acid recovery process The following steps are involved: S1: the gas outlet (2) and the material outlet (3) are closed, the heating element (4) is operated, and the temperature inside the furnace body (1) is monitored until the temperature inside the furnace body (1) rises to a set value; S2: the gas outlet (2) is opened, the waste acid is atomized and sprayed into the furnace body (1) through the spray gun (5), the shielding plate (6) is driven to rotate through the driving unit (7), and the amount of fixed products in the furnace body (1) is monitored; S3: When the amount of solid product reaches the set value, the discharge port (3) is opened; S4: After the fixed product is discharged, the discharge port (3) is closed.

2. A waste acid recovery process according to claim 1, characterized in that: The heating element (4) comprises a heating plate arranged in the furnace body (1), a filter hole (8) is provided on the heating plate, the discharge port (3), the heating plate, the spray gun (5) and the air outlet (2) are arranged in sequence from low to high; a driving shaft (9) is fixed on the rotating shaft of the baffle plate (6), a cleaning rod (10) is provided on the driving shaft (9), and bristles (12) are provided on the cleaning rod (10), and the bristles (12) are inserted into the filter hole (8).

3. A waste acid recovery process according to claim 2, characterized in that: The heating plate comprises a plurality of heating rods (41), the heating rods (41) being arranged in a staggered manner to form a mesh structure, the meshes of the mesh structure forming the filter holes (8); an electric heating wire is arranged in each of the heating rods (41), and a power supply component for supplying power to the electric heating wire is arranged on the furnace body (1).

4. A waste acid recovery process according to claim 2, characterized in that: A rotating ring (13) is rotatably arranged on the driving shaft (9), and a scraping rod (14) is arranged on the rotating ring (13) for scraping off particles adhering to the lower surface of the shielding plate (6).

5. A waste acid recovery process according to claim 4, characterized in that: A limiting groove (15) is provided on the driving shaft (9) along the circumferential direction, the rotating ring (13) is located in the limiting groove (15), and a ball (16) in contact with the limiting groove (15) is provided on the inner wall of the rotating ring (13).

6. A waste acid recovery process according to claim 2, characterized in that: The spray gun (5) is arranged to be inclined downward in a direction toward the heating plate.

7. A waste acid recovery process according to claim 1, characterized in that: There are multiple spray guns (5), and each spray gun tube of the spray gun (5) is provided with an air pressure sensor and a control valve; in step S2, the air pressure in the spray gun tube of the spray gun (5) is monitored by the air pressure sensor, and when the air pressure in the spray gun tube of the spray gun (5) reaches an abnormal value, the spray gun tube of the spray gun (5) is controlled to be closed by the control valve.

8. A waste acid recovery process according to claim 1, characterized in that: In step S1, the waste acid is preheated.

9. A waste acid recovery process according to claim 8, characterized in that: Before preheating the waste acid, the waste acid is first subjected to precipitation treatment.

10. A waste acid recovery process according to claim 9, characterized in that: A precipitation tank (20) is used to perform precipitation treatment on waste acid. A filtrate plate (21) is arranged in the precipitation tank (20). A liquid inlet (22) is provided on the precipitation tank (20), and the liquid inlet (22) is located below the filtrate plate (21). A liquid outlet (23) is provided on the precipitation tank (20), and the liquid outlet (23) is located above the filtrate plate (21).

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