Lead-containing flue ash pretreatment device and method

Abstract

A lead-containing flue ash pretreatment device and method, wherein an acid mixer is fixedly placed in the middle of a pretreatment device box, a sulfuric acid temporary storage tank, a flue ash temporary storage tank, and a viscosity agent temporary storage tank are fixedly placed on a top base of the pretreatment device box; the sulfuric acid temporary storage tank is connected to the upper end of the acid mixer through a sulfuric acid discharging pipe; the flue ash temporary storage tank is connected to the upper end of the acid mixer through a flue ash discharging pipe; the viscosity agent temporary storage tank is connected to the upper end of the acid mixer through a viscosity agent discharging pipe; the acid mixer comprises a box and a stirrer arranged inside the box, a flue ash acid mixing stirring motor is installed below the acid mixer, an output shaft of the flue ash acid mixing stirring motor is connected to the stirrer center shaft of the stirrer, an acid mixer discharge port is further arranged on one side of the acid mixer, a pneumatic discharge valve matching the acid mixer discharge port is arranged at the acid mixer discharge port, and the outer side of the pneumatic discharge valve is connected to the output end of an air pressure pump; the purpose of energy saving and consumption reduction is achieved, and the smoke dust rate of the subsequent smelting process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of smelting flue ash pretreatment devices, and in particular to a lead-containing flue ash pretreatment device and method. Background Art

[0002] At present, in the secondary lead smelting industry, during the smelting process of lead-containing materials, the flue ash collected by the flue dust collection system has a lead content of 65% according to the measurement, which mainly exists in the form of lead oxide, lead dioxide and lead sulfide. Other metals enter the flue ash in the form of sulfides, such as copper sulfide, tin sulfide, zinc sulfide, antimony sulfide, etc. At present, most of the same industry puts the collected flue ash and waste lead materials into the smelting furnace together with the flue dust collection system for re-smelting for secondary utilization. However, this method does not take into account the high melting point of lead sulfide and other sulfide metals in the flue ash during the melting process, which are not easy to be reduced and are easy to generate flue ash again. Even when the dust collection technology does not meet the requirements, lead dust and lead mist will be generated, causing secondary pollution to the environment. In addition, the recovery rate of lead and other precious metals is low, and the smoke dust rate is high. At present, the domestic recycled lead enterprises have an annual capacity of processing waste lead-acid batteries of more than 10 million tons, which will generate about 1 million tons of flue ash every year. In addition, the production capacity of the recycled lead industry is growing rapidly, so the above-mentioned problems need to be solved urgently. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a lead-containing flue ash pretreatment device, which reduces the melting point of the main components of the ash in the subsequent smelting process, achieves the purpose of energy saving and consumption reduction, and reduces the smoke rate in the subsequent smelting process.

[0004] The purpose of the present invention is also to provide a method for using the above-mentioned lead-containing flue ash pretreatment device - a flue ash pretreatment method.

[0005] A lead-containing flue ash pretreatment device, characterized in that: an acid mixing machine is fixedly placed in the middle of the pretreatment device box, and a sulfuric acid temporary storage tank, a flue ash temporary storage tank, and a thickener temporary storage tank are fixedly placed on the top base of the pretreatment device box; the sulfuric acid temporary storage tank is connected to the upper end of the acid mixing machine through a sulfuric acid discharge pipe, and a sulfuric acid discharge control valve is provided on the sulfuric acid discharge pipe; the flue ash temporary storage tank is connected to the upper end of the acid mixing machine through a flue ash discharge pipe; the thickener temporary storage tank is connected to the upper end of the acid mixing machine through a thickener discharge pipe, and a thickener discharge control valve is also provided on the thickener discharge pipe; the acid mixing machine includes a box and an agitator arranged inside the box, a sealing cover is provided at the upper end of the acid mixing machine, and a through hole matching the sulfuric acid discharge pipe, the flue ash discharge pipe, and the thickener discharge pipe is provided on the sealing cover, a flue ash mixed acid stirring motor is installed below the acid mixing machine, and the flue ash mixed acid The output shaft of the stirring motor is connected to the stirring center shaft of the stirrer, and a discharge port of the acid mixer is also provided on one side of the acid mixer, and a pneumatic discharge valve matching the discharge port of the acid mixer is provided at the discharge port of the acid mixer, and the outer side of the pneumatic discharge valve is connected to the output end of the air pressure pump; a central shaft sleeve is sleeved on the central shaft of the stirrer, and a plurality of stirring rods are evenly connected to the outer periphery of the central shaft sleeve, and the ends of the stirring rods are connected to the central shaft sleeve, and the tops of the stirring rods point to the outer casing of the acid mixer of the acid mixer; a first blade connecting shaft is vertically connected below the top of the stirring rod, and an outer ring inclined blade is connected to the bottom end of the first blade connecting shaft, and a second blade connecting shaft is vertically connected below the middle of the stirring rod, and an inner ring inclined blade is connected to the bottom end of the second blade connecting shaft, and the outer ring inclined blade and the inner ring inclined blade are inclinedly arranged with the stirring rod; the bottoms of the outer ring inclined blade and the inner ring inclined blade acid mixer are also inclined.

[0006] Six stirring rods are evenly connected to the outer periphery of the central shaft sleeve, the outer ring inclined blades have the same inclination angle as the inner ring inclined blades, and the inclination angle between the outer ring inclined blades, the inner ring inclined blades and the stirring rods is α; the angle between the outer ring inclined blades, the inner ring inclined blades and the bottom of the acid mixer is θ; the outer ring inclined blades and the inner ring inclined blades have the same length.

[0007] The inclination angle α between the outer ring inclined blades, the inner ring inclined blades and the stirring rod is 10-20°; the angle θ between the outer ring inclined blades, the inner ring inclined blades and the bottom of the acid mixer is 25-35°; the second blade connecting shaft is arranged at the stirring rod The outer ring inclined blades and the inner ring inclined blades have the same blade length; the outer ring inclined blades and the inner ring inclined blades have a blade length of 13-17cm.

[0008] The inclination angle α between the outer ring inclined blades, the inner ring inclined blades and the stirring rod is 13-17°; the angle θ between the outer ring inclined blades, the inner ring inclined blades and the bottom of the acid mixer is 28-32°.

[0009] The inclination angle α between the outer ring inclined blades, the inner ring inclined blades and the stirring rod is 15°; the angle θ between the outer ring inclined blades, the inner ring inclined blades and the bottom of the acid mixer is 30°; the length of the outer ring inclined blades and the inner ring inclined blades is 15 cm.

[0010] The sulfuric acid temporary storage tank, flue ash temporary storage tank, and thickener temporary storage tank are all cylindrical tanks, and are all made of PE plastic material. The bottom of the flue ash temporary storage tank is a trapezoid, and the upper base of the trapezoid is larger than the lower base of the trapezoid.

[0011] The acid mixer is a stainless steel cylindrical box, the acid mixer discharge port is arc-shaped, and the inner side of the pneumatic discharge valve is an arc-shaped that matches the acid mixer discharge port; a through hole matching the central axis of the agitator is also provided in the center of the sealing cover, the top of the central axis of the agitator passes through the through hole in the center of the sealing cover and is fixed at the upper end by a nut, the lower end of the central axis of the agitator is fixedly connected to the output shaft of the flue ash acid mixing stirring motor, and a bottom supporting foot is also provided at the four corners of the bottom of the pretreatment device box.

[0012] It also includes a mixing acid machine control cabinet for controlling a sulfuric acid discharge control valve, a viscous agent discharge control valve, and a flue ash mixed acid stirring motor. The sulfuric acid discharge control valve, the viscous agent discharge control valve, and the flue ash mixed acid stirring motor are electrically connected to the mixing acid machine control cabinet. The sulfuric acid discharge control valve and the viscous agent discharge control valve are both electric flow regulating valves.

[0013] A method for pretreating lead-containing flue ash, characterized in that it comprises the following steps:

[0014] Step 1): 100 parts by weight of leaded flue ash, 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18%, and 1 part by weight of a thickener are respectively placed in the flue ash temporary storage tank, sulfuric acid temporary storage tank, and thickener temporary storage tank of the leaded flue ash pretreatment device;

[0015] Step 2): 100 parts by weight of leaded flue ash are added to the acid mixer through the flue ash discharge pipe, and then the sulfuric acid discharge control valve on the sulfuric acid discharge pipe is opened, and 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18% are added to the acid mixer, and at the same time, the flue ash mixed acid stirring motor is turned on, the frequency is adjusted to 10 Hz, and the stirrer inside the acid mixer is driven to stir for 2 minutes, and 100 parts by weight of leaded flue ash and 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18% are evenly stirred to form a primary mixture;

[0016] Step 3): Open the viscous agent discharge control valve on the viscous agent discharge pipe, add 1 part by weight of the viscous agent into the acid mixer, and drive the agitator inside the acid mixer to continue stirring for 1 minute when the frequency of the flue ash acid mixing motor is 10 Hz, and stir and mix the primary mixture prepared in step 2) and 1 part by weight of the viscous agent to form a mixture;

[0017] Step 4): The mixture prepared in step 3) is stirred for 30 minutes by the agitator inside the acid mixer under the condition that the frequency of the flue ash acid mixing motor is 30 Hz, and a viscous paste-like flue ash is obtained after sufficient reaction.

[0018] The thickener is sodium humate, and its concentration is 20%-30%.

[0019] The beneficial effects of the present invention are:

[0020] 1. According to the difference in the content of lead sulfide, tin sulfide, etc. in the flue ash, the unit dosage of sulfuric acid is adjusted. During the flue ash stirring process, sulfuric acid and thickener are added to the flue ash at a certain ratio and flow rate. Through sufficient reaction, a viscous paste is formed, and then it is transported to the granulator through the discharge port for granulation; the process of converting the flue ash from powder to large particles is realized, and the smoke dust rate of the subsequent smelting process is reduced.

[0021] 2. The mixing of flue ash and sulfuric acid is realized, and the transformation from sulfide to sulfate is completed in the mixer, which reduces the melting point of the main components of the flue ash in the subsequent smelting process and achieves the purpose of energy saving and consumption reduction.

[0022] 3. The temporary storage tanks used are all equipped with scales. The sulfuric acid discharge control valve and the viscosity agent discharge control valve both use electric flow regulating valves with flow meters, which can control the feed flow in real time and ensure accurate batching during the experimental mixing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 This is a top view of the interior of the acid mixing machine of the present invention;

[0025] Figure 3 It is a partial structural schematic diagram of the agitator of the present invention;

[0026] Figure 4 It is a side view of the connection between the first blade connecting shaft and the outer ring inclined blade;

[0027] In the figure: 1. pretreatment device housing, 2. discharge port of acid mixing machine, 3. acid mixing machine, 3-1. agitator, 3-2. outer ring inclined blades, 3-3. acid mixing machine housing, 3-4. inner ring inclined blades, 3-5. central shaft sleeve, 3-6. air pressure pump, 3-7. pneumatic discharge valve, 3-8. second blade connecting shaft, 3-9. first blade connecting shaft, 3-10. nut, 4. sulfuric acid discharge control valve, 5. sulfuric acid discharge pipeline, 6. flue ash discharge pipeline, 7. sulfuric acid temporary storage tank, 8. flue ash temporary storage tank, 9. thickener temporary storage tank, 10. thickener discharge pipeline, 11. top base, 12. thickener discharge control valve, 13. acid mixing machine control cabinet, 14. flue ash mixed acid stirring motor, 14-1. agitator central shaft, 15. bottom support foot, 16. sealing cover. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will now be described clearly and completely in conjunction with the accompanying drawings. The accompanying drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner.

[0029] like Figure 1As shown, the present invention comprises a pretreatment device housing 1, wherein a mixed acid machine 3 is fixed in the middle layer of the pretreatment device housing 1, and a sulfuric acid temporary storage tank 7, a flue ash temporary storage tank 8 and a viscous agent temporary storage tank 9 are fixed in the upper layer, which are respectively connected to the mixed acid machine 3 through a sulfuric acid discharge pipe 5, a flue ash discharge pipe 6 and a viscous agent discharge pipe 10, wherein a sulfuric acid discharge control valve 4 is arranged on the sulfuric acid discharge pipe 5, and a viscous agent discharge control valve 12 is also arranged on the viscous agent discharge pipe 10, and the mixed acid machine 3 comprises a The box body and the stirrer 3-1 arranged inside the box body, the upper end of the acid mixer 3 is provided with a sealing cover 16, and the sealing cover 16 is provided with through holes matching the sulfuric acid discharge pipe 5, the flue ash discharge pipe 6, and the viscous agent discharge pipe 10, and the flue ash mixed acid stirring motor 14 is installed below the acid mixer 3, and the output shaft of the flue ash mixed acid stirring motor 14 is connected to the stirrer central shaft 14-1 of the stirrer 3-1, and the acid mixer 3 is also provided with a mixing outlet 2. The discharge port 2 is provided with a pneumatic discharge valve 3-7 matching the discharge port 2 of the acid mixer. The outer side of the pneumatic discharge valve 3-7 is connected to the output end of the air pressure pump 3-6. The flue ash after the mixed acid mixing is discharged through the discharge port 2 of the acid mixer to the conveyor belt below the outer side of the discharge port 2 of the acid mixer, and is transported to the granulator by the conveyor belt. The acid mixer 3 is fully enclosed, and the material of the acid mixer 3 is stainless steel, which is resistant to acid corrosion. The sulfuric acid temporary storage tank 7, the flue ash temporary storage tank 8, and the thickener temporary storage tank 9 They are all PE plastic cylindrical tanks, and the bottom cross-section of the flue ash temporary storage tank 8 is a trapezoid, and the upper bottom side of the trapezoid is larger than the lower bottom side of the trapezoid. The sulfuric acid temporary storage tank 7 and the viscosity agent temporary storage tank 9 are both scaled on the outside; a through hole matching the central axis 14-1 of the agitator is also provided in the center of the sealing cover 16. The central axis 14-1 of the agitator passes through the through hole in the center of the sealing cover 16 and is fixed at the upper end by a nut 3-7, and the lower end is fixedly connected to the output shaft of the flue ash mixed acid stirring motor 14.

[0030] It also includes a mixing acid machine control cabinet 13 for controlling the sulfuric acid discharge control valve 4, the viscous agent discharge control valve 12, and the flue ash mixed acid stirring motor 14. The sulfuric acid discharge control valve 4, the viscous agent discharge control valve 12, and the flue ash mixed acid stirring motor 14 are electrically connected to the mixing acid machine control cabinet 13; the sulfuric acid discharge control valve 4 and the viscous agent discharge control valve 12 are both electric flow regulating valves.

[0031] like Figure 2-3As shown, in the present invention, a central shaft sleeve 3-5 is sleeved on the central shaft 14-1 of the stirrer, and 6 stirring rods are evenly connected to the outer periphery of the central shaft sleeve 3-5, and the ends of the stirring rods are connected to the central shaft sleeve 3-5, and the tops of the stirring rods point to the mixing machine housing 3-3 of the acid mixer 3; a first blade connecting shaft 3-9 is vertically connected below the top of the stirring rod, and an outer ring inclined blade 3-2 is connected to the bottom end of the first blade connecting shaft 3-9, and a second blade connecting shaft 3-8 is vertically connected below the middle of the stirring rod, and an inner ring inclined blade 3-4 is connected to the bottom end of the second blade connecting shaft 3-8, and the outer ring inclined blade 3-2 and the inner ring inclined blade 3-3 are connected. -4 is inclined with the stirring stick, and the outer ring inclined blade 3-2 has the same inclination angle as the inner ring inclined blade 3-4, and the inclination angle of the outer ring inclined blade 3-2, the inner ring inclined blade 3-4 and the stirring stick is α; the inclination angle α of the outer ring inclined blade 3-2, the inner ring inclined blade 3-4 and the stirring stick is 10-20°, further, the inclination angle α of the outer ring inclined blade, the inner ring inclined blade and the stirring stick is 13-17°; further, the inclination angle α is 15°, and the inclination angle α of 15° can make the material mixing more uniform and increase the material viscosity by more than 30%; the second blade connecting shaft 3-8 is arranged at the stirring stick The outer ring inclined blades 3-2 and the inner ring inclined blades 3-4 have the same blade length, and the outer ring inclined blades 3-2 and the inner ring inclined blades 3-4 have a blade length of 13-17cm. Further, the outer ring inclined blades 3-2 and the inner ring inclined blades 3-4 have a blade length of 15cm.

[0032] like Figure 4 As shown, the outer ring inclined blades 3-2, the inner ring inclined blades 3-4 and the bottom of the acid mixer 3 are also inclined, and the angle between the outer ring inclined blades 3-2, the inner ring inclined blades 3-4 and the bottom of the acid mixer 3 is θ; the angle between the outer ring inclined blades 3-2, the inner ring inclined blades 3-4 and the bottom of the acid mixer 3 is 25-35°, and further, the angle between the outer ring inclined blades 3-2, the inner ring inclined blades and the bottom of the acid mixer 3 is 28-32°

[0033] ; Further, the angle θ is 30°; the setting of the angle θ of 30°, when the agitator is working, can make the material flow to the discharge port 2, accelerate the discharge speed of the material, thereby reducing the production time, and can improve the production efficiency by 20%.

[0034] Steps:

[0035] Step 1): 100 parts by weight of leaded flue ash, 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18%, and 1 part by weight of a thickener are respectively placed in the flue ash temporary storage tank 8, the sulfuric acid temporary storage tank 7, and the thickener temporary storage tank 9 of the leaded flue ash pretreatment device;

[0036] Step 2): 100 parts by weight of leaded flue ash are added to the acid mixer 3 through the flue ash discharge pipe 6, and then the sulfuric acid discharge control valve 4 on the sulfuric acid discharge pipe 5 is opened, and 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18% are added to the acid mixer 3, and at the same time, the flue ash mixed acid stirring motor 14 is turned on, and the frequency is adjusted to 10 Hz, driving the stirrer 3-1 inside the acid mixer 3 to stir for 2 minutes, and 100 parts by weight of leaded flue ash and 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18% are evenly stirred to form a primary mixture;

[0037] Step 3): Open the viscous agent discharge control valve 12 on the viscous agent discharge pipe 10, add 1 part by weight of the viscous agent into the acid mixer 3, and drive the agitator 3-1 inside the acid mixer 3 to continue stirring for 1 minute when the frequency of the flue ash acid mixing stirring motor 14 is 10 Hz, and stir and mix the primary mixed material prepared in step 2) and 1 part by weight of the viscous agent to form a mixed material;

[0038] Step 4): The mixture prepared in step 3) is stirred for 30 minutes by the agitator 3-1 inside the acid mixer 3 under the condition that the frequency of the flue ash mixed acid stirring motor 14 is 30Hz, and a viscous paste flue ash is obtained after sufficient reaction; further, the viscous agent is sodium humate with a concentration of 20%-30%, and the sodium humate solution has good bonding properties; the dilute sulfuric acid with a sulfuric acid content of 18% can be obtained by acid pouring from waste and rich liquid batteries;

[0039] Finally, the air pressure pump 3-6 is turned on, and then the air pressure pump 3-6 drives the pneumatic discharge valve 3-7 to retreat, and the discharge port 2 of the acid mixer is opened. The viscous paste flue ash obtained in step 4) is continuously stirred by the stirrer 3-1 to be discharged through the discharge port 2 of the acid mixer to the belt below the discharge port 2 of the acid mixer, and then transported to the granulator to complete the granulation work.

[0040] Embodiment 1:

[0041] After 100 parts by mass of flue ash, 25 parts by mass of dilute sulfuric acid with a sulfuric acid content of 18%, and 1 part by mass of a thickener are uniformly mixed through the above steps, the obtained viscous paste flue ash is in a viscous muddy state and has a moisture content of 16.4%.

[0042] Embodiment 2:

[0043] After 100 parts by mass of flue ash, 20 parts by mass of dilute sulfuric acid with a sulfuric acid content of 18%, and 1 part by mass of a thickening agent are uniformly mixed through the above steps, the obtained viscous paste flue ash is in a viscous wet paste state, and the moisture content reaches 13.6%.

[0044] Embodiment 3:

[0045] After 100 parts by mass of flue ash, 16 parts by mass of dilute sulfuric acid with a sulfuric acid content of 18%, and 1 part by mass of a thickener are uniformly mixed through the above steps, the obtained viscous paste flue ash is in a viscous paste state and naturally agglomerates, obtaining a new type of large-particle spherical ash with a moisture content of 11.3%.

[0046] Embodiment 4:

[0047] After 100 parts by mass of flue ash, 13 parts by mass of dilute sulfuric acid with a sulfuric acid content of 18%, and 1 part by mass of a thickener are uniformly mixed through the above steps, the resulting viscous paste flue ash is loose, non-agglomerated, has no large particles of spherical ash, and has a moisture content of 9.4%.

Claims

1. A method for pretreating lead-containing flue ash, characterized in that: The invention comprises a pretreatment device, wherein the pretreatment device comprises a pretreatment device housing (1), an acid mixer (3) is fixedly placed in the middle of the pretreatment device housing (1), and a sulfuric acid temporary storage tank (7), a flue ash temporary storage tank (8), and a thickener temporary storage tank (9) are fixedly placed on a top base (11) of the pretreatment device housing (1); the sulfuric acid temporary storage tank (7) is connected to the upper end of the acid mixer (3) through a sulfuric acid discharge pipe (5), and a sulfuric acid discharge control valve (4) is provided on the sulfuric acid discharge pipe (5); the flue ash temporary storage tank (8) is connected to the upper end of the acid mixer (3) through a flue ash discharge pipe (6); the thickener The temporary storage tank (9) is connected to the upper end of the acid mixer (3) through a viscous agent discharge pipe (10), and the viscous agent discharge pipe (10) is also provided with a viscous agent discharge control valve (12); the acid mixer (3) comprises a box body and an agitator (3-1) arranged inside the box body, a sealing cover (16) is provided at the upper end of the acid mixer (3), and the sealing cover (16) is provided with through holes matching the sulfuric acid discharge pipe (5), the flue ash discharge pipe (6), and the viscous agent discharge pipe (10), and a flue ash mixed acid stirring motor (14) is installed below the acid mixer (3), and the flue ash mixed acid stirring motor (14) The output shaft is connected to the stirrer central axis (14-1) of the stirrer (3-1); an acid mixer outlet (2) is also provided on one side of the acid mixer (3); a pneumatic discharge valve (3-7) matching the acid mixer outlet (2) is provided at the acid mixer outlet (2); the outer side of the pneumatic discharge valve (3-7) is connected to the output end of the air pressure pump (3-6); a central shaft sleeve (3-5) is sleeved on the stirrer central axis (14-1); a plurality of stirring rods are evenly connected on the outer periphery of the central shaft sleeve (3-5); the ends of the stirring rods are connected to the central shaft sleeve (3-5), and the top ends of the stirring rods point to the acid mixer (3). A housing (3-3) of an acid mixer; a first blade connecting shaft (3-9) is vertically connected below the top of the stirring rod, an outer ring inclined blade (3-2) is connected to the bottom of the first blade connecting shaft (3-9), a second blade connecting shaft (3-8) is vertically connected below the middle of the stirring rod, an inner ring inclined blade (3-4) is connected to the bottom of the second blade connecting shaft (3-8), the outer ring inclined blade (3-2) and the inner ring inclined blade (3-4) are arranged in an inclined manner with the stirring rod, and the outer ring inclined blade (3-2) and the inner ring inclined blade (3-4) are also arranged in an inclined manner with the bottom of the acid mixer (3); Six stirring rods are evenly connected to the outer periphery of the central shaft sleeve (3-5); the outer ring inclined blades (3-2) and the inner ring inclined blades (3-4) have the same inclination angle; the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the stirring rods have an inclination angle of α; the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the bottom of the acid mixer (3) have an included angle of θ; the outer ring inclined blades (3-2) and the inner ring inclined blades (3-4) have the same blade length; the second blade connecting shaft (3-8) is arranged at the stirring rod Department; The pretreatment method includes the following steps: Step 1): 100 parts by weight of leaded flue ash, 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18%, and 1 part by weight of a thickener are respectively placed in the flue ash temporary storage tank (8), the sulfuric acid temporary storage tank (7), and the thickener temporary storage tank (9) of the above-mentioned pretreatment device; Step 2): 100 parts by weight of leaded flue ash are added to the acid mixer (3) through the flue ash discharge pipe (6), and then the sulfuric acid discharge control valve (4) on the sulfuric acid discharge pipe (5) is opened, and 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18% are added to the acid mixer (3). At the same time, the flue ash acid mixing stirring motor (14) is turned on and the frequency is adjusted to 10 Hz to drive the stirrer (3-1) inside the acid mixer (3) to stir for 2 minutes, and 100 parts by weight of leaded flue ash and 13-25 parts by weight of dilute sulfuric acid with a sulfuric acid content of 18% are evenly stirred to form a primary mixture; Step 3): Open the viscous agent discharge control valve (12) on the viscous agent discharge pipe (10), add 1 part by weight of the viscous agent into the acid mixer (3), and drive the agitator (3-1) inside the acid mixer (3) to continue stirring for 1 minute when the frequency of the flue ash acid mixing agitator motor (14) is 10 Hz, and stir and mix the primary mixed material prepared in step 2) and 1 part by weight of the viscous agent to form a mixed material; Step 4): The mixture prepared in step 3) is stirred for 30 minutes by the agitator (3-1) inside the acid mixer (3) under the condition that the frequency of the flue ash acid mixing motor (14) is 30 Hz, and a viscous paste-like flue ash is obtained after sufficient reaction.

2. A method for pretreating lead-containing flue ash according to claim 1, characterized in that: The inclination angle α between the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the stirring rod is 10-20°; the angle θ between the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the bottom of the acid mixer (3) is 25-35°; the second blade connecting shaft (3-8) is arranged at the stirring rod. The outer ring inclined blades (3-2) and the inner ring inclined blades (3-4) have a blade length of 13-17 cm.

3. A method for pretreating lead-containing flue ash according to claim 1, characterized in that: The inclination angle α between the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the stirring rod is 13-17°; the angle θ between the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the bottom of the acid mixer (3) is 28-32°.

4. A method for pretreating lead-containing flue ash according to claim 1, characterized in that: The inclination angle α between the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the stirring rod is 15°; the angle θ between the outer ring inclined blades (3-2), the inner ring inclined blades (3-4) and the bottom of the acid mixer (3) is 30°; and the blade lengths of the outer ring inclined blades (3-2) and the inner ring inclined blades (3-4) are 15 cm.

5. The method for pretreating lead-containing flue ash according to claim 1, characterized in that: The sulfuric acid temporary storage tank (7), the flue ash temporary storage tank (8), and the thickener temporary storage tank (9) are all cylindrical tanks, and the sulfuric acid temporary storage tank (7), the flue ash temporary storage tank (8), and the thickener temporary storage tank (9) are all made of PE plastic material; the bottom of the flue ash temporary storage tank (8) is a trapezoidal cross-section, and the upper bottom side of the trapezoid is larger than the lower bottom side of the trapezoid.

6. A method for pretreating lead-containing flue ash according to claim 1, characterized in that: The acid mixer (3) is a stainless steel cylindrical box, the acid mixer discharge port (2) is arc-shaped, and the inner side surface of the pneumatic discharge valve (3-7) is an arc-shaped that matches the acid mixer discharge port (2); the sealing cover (16) is also provided with a through hole matching the central axis (14-1) of the agitator at the center, the top of the central axis (14-1) of the agitator passes through the through hole in the center of the sealing cover (16) and is fixed by a nut (3-10), the lower end of the central axis (14-1) of the agitator is fixedly connected to the output shaft of the flue ash acid mixing motor (14), and the four corners of the bottom of the pretreatment device box (1) are respectively provided with a bottom support foot (15).

7. A method for pretreating lead-containing flue ash according to claim 1, characterized in that: The invention also comprises an acid mixing machine control electric cabinet (13) for controlling a sulfuric acid discharge control valve (4), a viscous agent discharge control valve (12), and a flue ash mixed acid stirring motor (14); the sulfuric acid discharge control valve (4), the viscous agent discharge control valve (12), and the flue ash mixed acid stirring motor (14) are electrically connected to the acid mixing machine control electric cabinet (13); and the sulfuric acid discharge control valve (4) and the viscous agent discharge control valve (12) are both electric flow regulating valves.

8. The method for pretreating lead-containing flue ash according to claim 1, characterized in that: The thickener is sodium humate, and its concentration is 20%-30%.

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