Spraying and soaking device and method for curing heavy metal in waste catalyst

Abstract

The invention relates to the technical field of landfill hazardous waste treatment, and provides a spraying and soaking device and method for curing waste catalyst heavy metal, which can solve the problem that large blocky and granular catalysts are difficult to cure by traditional cement through a process of spraying lime water and fully contacting and soaking waste in spiral stirring. According to the technology, for waste with toxic leaching (heavy metal and corrosive PH) exceeding the standard, especially for mercury and arsenic type heavy metal which is particularly difficult to treat, the use amount of a curing agent is reduced, the operation cost is reduced, and the treatment efficiency is greatly improved, the invention discloses a spraying and soaking device for curing heavy metal in a waste catalyst. The spraying and soaking device comprises a bearing frame body, a spiral rotating transmission shaft, a medicament box, a spraying and dosing system and a discharging assembly, by means of the technical scheme, the problems that in the prior art, for heavy metal which is particularly difficult to treat mercury and arsenic, the use amount of curing agents is large, the operation cost is high, and the treatment efficiency is low are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of landfill hazardous waste treatment, and in particular to a spray soaking device and method for solidifying heavy metals in waste catalysts. Background Art

[0002] At present, there are two main types of hazardous waste landfills, namely flexible and rigid landfills. Flexible landfills have been widely used due to their low cost, relatively mature technology and simple operation. However, the requirements for incoming waste are relatively strict. A large part of hazardous waste requires pretreatment measures such as stabilization or solidification before entering the landfill. The main form of disposal process for stabilized or solidified waste is cement and chelating agent solidification. For heavy metals such as mercury and arsenic that are particularly difficult to treat, the amount of solidifying agent used is high, the operating cost is also high, and the disposal efficiency is low. Therefore, we proposed a spray soaking device and method for solidifying heavy metals in waste catalysts. The process can replace the traditional cement solidification of large blocks and granular catalysts by spraying lime water to fully contact and soak the waste in spiral stirring. This process is aimed at wastes with excessive toxic leaching (heavy metals, corrosive pH), especially for heavy metals such as mercury and arsenic that are particularly difficult to treat. It not only reduces the amount of solidifying agent used and reduces operating costs, but also greatly improves disposal efficiency. Summary of the Invention

[0003] The present invention proposes a spray soaking device and method for solidifying heavy metals in waste catalysts, which solves the problems in the related art of heavy metals such as mercury and arsenic being particularly difficult to treat, requiring a high amount of solidifying agents, resulting in high operating costs and low disposal efficiency.

[0004] The technical solution of the present invention is as follows: a spray soaking device for solidifying heavy metals in spent catalysts, comprising a load-bearing frame, a feed hopper, a spiral rotating transmission shaft, a feed port, an inclined feed hopper, a reagent box, a water tank, a spray dosing system and a discharge assembly;

[0005] The conveying hopper is installed on the load-bearing frame, and a U-shaped groove is provided on the top of the conveying hopper;

[0006] The spiral rotating transmission shaft is rotatably installed in the feed hopper;

[0007] The feed port is connected to the top of the feed hopper;

[0008] The inclined feed hopper is connected to the top of the feed port;

[0009] The medicine box is located on one side of the load-bearing frame;

[0010] The water tank is installed on one side of the medicine box;

[0011] The spray dosing system is installed between the medicine box and the water tank;

[0012] The discharge assembly is installed on the lower side of the conveying bucket.

[0013] Furthermore, the spray dosing system includes:

[0014] A transverse main pipeline, the transverse main pipeline is located on the upper side of the feeding hopper, and the medicine box and the water tank are respectively connected to the transverse main pipeline via a dosing pipe and a water inlet pipe, and the dosing pipe and the water inlet pipe are respectively provided with a dosing pump and a control valve;

[0015] Diversion pipes, wherein the number of the diversion pipes is 23, and the 23 diversion pipes are connected in an array to the transverse main pipe;

[0016] A spray pipe, the spray pipe being connected to each of the diversion pipes;

[0017] The solid conical nozzles are provided in 10 pieces and are evenly distributed on the lower side of each of the spray pipes.

[0018] Furthermore, the diameter of the spiral body of the rotating transmission shaft is 600 mm, the U-shaped diameter of the feed hopper shell is 656 mm, the thickness of the spiral blade of the spiral rotating transmission shaft is 8 mm, and the feed hopper, the spiral rotating transmission shaft and the spiral blade are all made of corrosion-resistant steel.

[0019] Furthermore, the effective spraying length of the spray dosing system is 4.5m and 600mm wide, with an effective area of ​​2.4m 2 The effective residence time of waste is 10s, the inner diameter of the transverse main pipe is 25mm, the diameter of the diversion pipe is 15mm, and the diameter of the spray pipe is 15mm.

[0020] Furthermore, the discharge assembly includes:

[0021] An iron trough, the iron trough being located directly below the lower hopper of the feed hopper, and a discharge door being provided on one side of the iron trough;

[0022] A vibration separation frame, the vibration separation frame is located at the lower side of the discharge door;

[0023] A lower liquid rack, wherein two lower liquid racks are provided, and the two lower liquid racks are staggered and arranged on one side of the vibration separation rack;

[0024] The liquid receiving trough is provided in two pieces, and the two liquid receiving troughs are respectively located at the lower sides of the two lower liquid racks.

[0025] Furthermore, a driving motor is installed on the top of the load-bearing frame, and a reducer is fixedly connected to the output end of the driving motor to drive the spiral rotating transmission shaft to rotate.

[0026] A spray soaking method for solidifying heavy metals in spent catalysts uses a spray soaking device for solidifying heavy metals in spent catalysts in the above-mentioned scheme, comprising the following steps:

[0027] S1. According to the appearance properties of the materials, estimate how much lime water is needed to completely mix and react with the waste. Different process parameters are selected according to different waste materials. First, small pieces of catalyst, small pieces of sludge, small pieces of solid waste residue, etc. are of one order of magnitude, and 0.08-0.1 times of 10% concentration of lime water is required; second, zinc slag, granular catalyst, granular sludge and other wastes are of one order of magnitude, and about 0.1-0.12 times of 10% concentration of lime water is required; third, zinc ash, zinc dust, fine powder sludge, dust removal ash and other wastes are of one order of magnitude, and 0.15-0.20 times of 10% concentration of lime water is required. The amount of lime water added can also be further adjusted according to the appearance properties of the waste discharge so that the lime water can fully contact and react with the material;

[0028] S2. Wastes with a small amount of excessive toxic and corrosive properties, wastes with a small amount of excessive heavy metals, and wastes with a small amount of excessive inorganic fluorides are placed into the device respectively. During the spiral stirring process, the Ca2+ and OH- ions in the lime water can react with the H+, heavy metals, and inorganic fluorides in the waste as follows: H+ reacts with the OH- in the lime water (H++OH-=H2O) for a neutralization reaction; the hydroxide solubility product constant Ksp of heavy metals (Class I: cadmium, lead; Class II: nickel, zinc, etc.) is extremely small, and such heavy metals are very easy to combine with OH- to form a precipitate; F- fully reacts with the Ca2+ in the lime water (F-+Ca2+=CaF2↓) to form a CaF2 precipitate that is hardly soluble in water; the wastes with the above characteristics are placed in the device, and after the lime water and the wastes are fully contacted and reacted during the spray stirring process, the effects of neutralizing acidity, removing heavy metals, and removing inorganic fluorides can be achieved.

[0029] S3, stabilization and curing: the waste after reaction is collected in an iron trough and sent to the curing workshop for curing for 24 to 48 hours;

[0030] S4. Sample testing: After curing, samples are taken to the laboratory for waste toxicity leaching testing based on the indicators required for entering the landfill;

[0031] S5. Safe landfill: After testing all indicators of the waste and ensuring that they are fully qualified, safe landfill can be carried out.

[0032] The working principle and beneficial effects of the present invention are:

[0033] In the present invention, through the coordination of a load-bearing frame, a feed hopper, a spiral rotating transmission shaft, a feed hopper, an inclined feed hopper, a reagent box, a water tank, a spraying and dosing system, and a discharge assembly, it is convenient to fully contact and soak the waste in the spiral stirring by spraying lime water, thereby replacing the problem of difficulty in solidifying large blocks and granular catalysts with traditional cement. This process is aimed at waste with excessive toxic leaching (heavy metals, corrosive pH), especially mercury and arsenic, a type of heavy metal that is particularly difficult to treat, and is convenient for reducing the use of solidification agents, so as to reduce operating costs and thus improve disposal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Figure 1 It is a schematic structural diagram of the present invention as a whole;

[0036] Figure 2 For the present invention Figure 1 Schematic diagram of the local enlarged structure at A in the middle;

[0037] Figure 3 This is a schematic diagram of the planar structure of the coordination of the transverse main pipeline, the branch pipeline and the spray pipeline of the present invention;

[0038] Figure 4 For the present invention Figure 3 Schematic diagram of the local enlarged structure at B in the middle;

[0039] Figure 5 It is a schematic structural diagram of the curing process of the present invention.

[0040] In the figure: 1. load-bearing frame; 2. feed hopper; 3. spiral rotating drive shaft; 4. feed port; 5. inclined feed hopper; 6. reagent box; 7. water tank; 8. transverse main pipeline; 9. diversion pipeline; 10. spray pipeline; 11. solid cone nozzle; 12. iron trough; 13. vibration separation frame; 14. lower liquid frame; 15. liquid receiving tank; 16. drive motor; 17. reducer; 18. dosing pipe; 19. water inlet pipe. DETAILED DESCRIPTION

[0041] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0042] Example 1

[0043] like Figures 1 to 5As shown, this embodiment proposes a spray soaking device for solidifying heavy metals in waste catalysts, including a load-bearing frame 1, a feed hopper 2, a spiral rotating transmission shaft 3, a feed port 4, an inclined feed hopper 5, a reagent box 6, a water tank 7, a spray dosing system and a discharge assembly. The feed hopper 2 is installed on the load-bearing frame 1, and a U-shaped groove is opened on the top of the feed hopper 2. The spiral rotating transmission shaft 3 is rotatably installed in the feed hopper 2. The diameter of the spiral rotating transmission shaft 3 is 600mm, and the diameter of the U-shaped shell of the feed hopper 2 is 656m. m, the thickness of the spiral blade of the spiral rotating transmission shaft 3 is 8mm, the feed hopper 2, the spiral rotating transmission shaft 3 and the spiral blade are all made of corrosion-resistant steel, the feed port 4 is connected to the top of the feed hopper 2, and the opening and closing can be controlled from the inside, the inclined feed hopper 5 is connected to the top of the feed port 4, and the opening and closing can be controlled from the inside, the medicine box 6 is located on one side of the load-bearing frame 1, the water tank 7 is installed on one side of the medicine box 6, the spray dosing system is installed between the medicine box 6 and the water tank 7, and the discharge assembly is installed on the lower side of the feed hopper 2.

[0044] refer to Figure 3 as well as Figure 4 , the spray dosing system includes a transverse main pipe 8, a branch pipe 9, a spray pipe 10 and a solid conical nozzle 11. The transverse main pipe 8 is located on the upper side of the feed hopper 2, and the medicine box 6 and the water tank 7 are connected to the transverse main pipe 8 with a dosing pipe 18 and a water inlet pipe 19 respectively. The dosing pipe 18 and the water inlet pipe 19 are respectively provided with a dosing pump and a control valve, which can control the amount of medicine and water added. The branch pipe 9 is set to 23, and the 23 branch pipes 9 are connected to the transverse main pipe 8 in an array. The spray pipe 10 is connected to each branch pipe 9, and the solid conical nozzle 11 is set to 10. The 10 solid conical nozzles 11 are evenly distributed on the lower side of each spray pipe 10. A dense solid conical nozzle 11 is provided at the bottom of the spray pipe 10 so that the spray agent efficiently covers the entire upper surface of the U-groove spiral device;

[0045] By starting the dosing pump and the control valve, the medicine and water in the medicine box 6 and the water tank 7 can be mixed in the horizontal main pipe through the dosing pipe 18 and the water inlet pipe 19 respectively. At the same time, the waste in the conveying bucket 2 can be evenly sprayed through the U-shaped groove through multiple branch pipes 9, multiple spray pipes 10 and multiple solid cone nozzles 11.

[0046] refer to Figure 1 、 Figure 2 as well as Figure 3 The effective spray length of the spray dosing system is 4.5m and the width is 600mm, with an effective area of ​​2.4m 2The effective residence time of waste is 10s. The inner diameter of the horizontal main pipe 8 is 25mm, the diameter of the branch pipe 9 is 15mm, and the diameter of the spray pipe 10 is 15mm. Each spray pipe 10 has 10 solid conical nozzles 11 evenly distributed at the bottom, totaling 230 nozzles. The spray hole diameter is 1.25mm and the spray angle is 43°. This ensures that each water outlet has a certain pressure, ensuring uniform water output from the spray system and an effective spraying area, so that the waste is better contacted with the lime water. The total flow rate of lime water can be adjusted to achieve the effect of controlling the amount of lime water added. The amount of lime milk sprayed per hour can reach 3.6 to 10.5 tons.

[0047] refer to Figure 1 The discharge assembly includes an iron trough 12, a vibrating separation frame 13, a lower liquid frame 14 and a liquid receiving trough 15. The iron trough 12 is located directly below the lower hopper of the feed hopper 2. A discharge door is provided on one side of the iron trough 12. The vibrating separation frame 13 is located below the discharge door for solid-liquid separation. Two lower liquid frames 14 are provided. The two lower liquid frames 14 are staggered on one side of the vibrating separation frame 13. Two liquid receiving troughs 15 are provided. The two liquid receiving troughs 15 are respectively located below the two lower liquid frames 14.

[0048] The waste liquid from the feed hopper 2 can enter the vibration separation frame 13 through the lower hopper. At the same time, through the vibration of the vibration separation frame 13, the waste liquid can be staggered through the two lower liquid frames 14 and enter the two liquid receiving tanks 15 respectively, thereby improving the collection and treatment effect of the waste liquid.

[0049] refer to Figure 1 , a driving motor 16 is installed on the top of the load-bearing frame 1, and a reducer 17 is fixedly connected to the output end of the driving motor 16 to drive the spiral rotating transmission shaft 3 to rotate;

[0050] By starting the drive motor 16, the drive motor 16 can drive the spiral rotating transmission shaft 3 to rotate through the reducer 17, so that the waste in the feed hopper 2 can be fully stirred and transported. At the same time, the power of the drive motor 16 is 22kw, and the reducer 17 is equipped to make the speed of the spiral rotating transmission shaft 3 15r / min, which greatly increases the torque and can also process waste with higher hardness such as slag, greatly reducing the occurrence of faults such as jamming, and can reach an output of 30 tons / hour.

[0051] A spray soaking method for solidifying heavy metals in spent catalysts uses a spray soaking device for solidifying heavy metals in spent catalysts in the above-mentioned scheme, comprising the following steps:

[0052] Step 1. According to the appearance properties of the materials, estimate how much lime water is needed to completely mix and react with the waste, and select different process parameters according to different waste materials. First, small pieces of catalyst, small pieces of sludge, small pieces of solid waste residue, etc. are of the same order of magnitude, and 0.08-0.1 times of 10% concentration of lime water is required; second, zinc slag, granular catalyst, granular sludge and other wastes are of the same order of magnitude, and about 0.1-0.12 times of 10% concentration of lime water is required; third, zinc ash, zinc dust, fine powder sludge, dust removal ash and other wastes are of the same order of magnitude, and 0.15-0.20 times of 10% concentration of lime water is required. The amount of lime water added can also be further adjusted according to the appearance properties of the waste discharge so that the lime water can fully contact and react with the materials;

[0053] Step 2: respectively put waste with a small amount of excessive poisonous corrosiveness, waste with a small amount of excessive heavy metals, and waste with a small amount of excessive inorganic fluoride into the device. During the spiral stirring process, the Ca2+ and OH- ions in the lime water can react with the H+, heavy metals, and inorganic fluorides in the waste as follows: H+ and OH- in the lime water undergo a neutralization reaction (H++OH-=H2O); the hydroxide solubility product constant Ksp of heavy metals (class one: cadmium, lead; class two: nickel, zinc, etc.) is extremely small, and such heavy metals are very easy to combine with OH- to form a precipitate; F- fully reacts with the Ca2+ in the lime water (F-+Ca2+=CaF2↓) to form a CaF2 precipitate that is insoluble in water; waste with the above characteristics is put into this device, and after the lime water is fully contacted and reacted with the waste in the spray stirring process, the effects of neutralizing acidity, removing heavy metals, and removing inorganic fluorides can be achieved.

[0054] Step 3: Stabilization and curing: The waste after reaction is collected in an iron trough 12 and sent to a curing workshop for curing for 24 to 48 hours.

[0055] Step 4: Sample testing: After curing, take samples to the laboratory for waste toxicity leaching testing for the indicators required for entering the landfill;

[0056] Step 5. Safe landfill: Test all indicators of the waste and landfill it safely after it is fully qualified.

[0057] Example 2

[0058] This solidification process can remove heavy metals such as cadmium, lead, nickel, and zinc in toxic leaching, but it is not limited to such heavy metals, such as copper and chromium, because the Ksp of hydroxides of copper, chromium, etc. is much smaller than the Ksp of zinc, and they are more likely to form precipitation with hydroxide than zinc. Among them, copper is a relatively precious heavy metal and is inactive. Wastes containing copper with excessive toxicity are rare and are, in principle, suitable for the spray solidification process of the present invention. Wastes with only excessive chromium can be removed by this process, while wastes with excessive hexavalent chromium need to be solidified by adding ferrous water.

[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A spray soaking device for solidifying heavy metals in waste catalysts, characterized in that: include: load-bearing frame (1); A feeding hopper (2), the feeding hopper (2) being mounted on the load-bearing frame (1), and a U-shaped groove being provided at the top end of the feeding hopper (2); A spiral rotating transmission shaft (3), wherein the spiral rotating transmission shaft (3) is rotatably mounted in the feed hopper (2); A feed port (4), the feed port (4) being connected to the top end of the feed hopper (2); An inclined feed hopper (5), the inclined feed hopper (5) being connected to the top end of the feed port (4); A medicine box (6), the medicine box (6) is located on one side of the load-bearing frame (1); A water tank (7), the water tank (7) being installed on one side of the medicine box (6); A spraying and dosing system, wherein the spraying and dosing system is installed between the medicine box (6) and the water tank (7); A discharge assembly is installed on the lower side of the conveying bucket.

2. The spray soaking device for solidifying heavy metals in waste catalysts according to claim 1, characterized in that: The spray dosing system comprises: A transverse main pipe (8), the transverse main pipe (8) is located on the upper side of the feed hopper (2), and the medicine box (6) and the water tank (7) are respectively connected to the transverse main pipe (8) via a dosing pipe (18) and a water inlet pipe (19), and the dosing pipe (18) and the water inlet pipe (19) are respectively provided with a dosing pump and a control valve; Diversion pipes (9), the number of the diversion pipes (9) is 23, and the 23 diversion pipes (9) are connected in an array to the transverse main pipe (8); A spray pipe (10), wherein the spray pipe (10) is connected to each of the branch pipes (9); Solid conical nozzles (11), the solid conical nozzles (11) are arranged in 10 pieces, and the 10 solid conical nozzles (11) are evenly distributed on the lower side of each of the spray pipes (10).

3. The spray soaking device for solidifying heavy metals in waste catalysts according to claim 2, characterized in that: The diameter of the spiral rotating transmission shaft (3) is 600 mm, the U-shaped diameter of the outer shell of the feed hopper (2) is 656 mm, the thickness of the spiral blade of the spiral rotating transmission shaft (3) is 8 mm, and the feed hopper (2), the spiral rotating transmission shaft (3) and the spiral blade are all made of corrosion-resistant steel.

4. The spray soaking device for solidifying heavy metals in waste catalysts according to claim 3, characterized in that: The effective spraying length of the spray dosing system is 4.5m and the width is 600mm, and the effective area is 2.4m 2 The effective residence time of the waste is 10s, the inner diameter of the transverse main pipe (8) is 25mm, the diameter of the diversion pipe (9) is 15mm, and the diameter of the spray pipe (10) is 15mm.

5. The spray soaking device for solidifying heavy metals in waste catalysts according to claim 4, characterized in that: The discharge assembly comprises: An iron trough (12), the iron trough (12) is located directly below the lower hopper of the feed hopper (2), and a discharge door is provided on one side of the iron trough (12); a vibration separation frame (13), the vibration separation frame (13) being located on the lower side of the discharge door; A lower liquid rack (14), wherein two lower liquid racks (14) are provided, and the two lower liquid racks (14) are staggeredly provided on one side of the vibration separation rack (13); The liquid receiving trough (15) is provided in two pieces, and the two liquid receiving troughs (15) are respectively located at the lower sides of the two lower liquid racks (14).

6. The spray soaking device for solidifying heavy metals in waste catalysts according to claim 5, characterized in that: A driving motor (16) is installed at the top of the load-bearing frame (1), and a speed reducer (17) is fixedly connected to the output end of the driving motor (16) for driving the spiral rotating transmission shaft (3) to rotate.

7. A spray soaking method for solidifying heavy metals in spent catalysts, using the spray soaking device for solidifying heavy metals in spent catalysts as described in claims 1 to 6, characterized in that: The following steps are involved: S1. According to the appearance properties of the materials, estimate how much lime water is needed to completely mix and react with the waste. Different process parameters are selected according to different waste materials. First, small pieces of catalyst, small pieces of sludge, small pieces of solid waste residue, etc. are of one order of magnitude, and 0.08-0.1 times of 10% concentration of lime water is required; second, zinc slag, granular catalyst, granular sludge and other wastes are of one order of magnitude, and about 0.1-0.12 times of 10% concentration of lime water is required; third, zinc ash, zinc dust, fine powder sludge, dust removal ash and other wastes are of one order of magnitude, and 0.15-0.20 times of 10% concentration of lime water is required. The amount of lime water added can also be further adjusted according to the appearance properties of the waste discharge so that the lime water can fully contact and react with the material; S2. Wastes with a small amount of excessive toxic and corrosive properties, wastes with a small amount of excessive heavy metals, and wastes with a small amount of excessive inorganic fluorides are placed into the device respectively. During the spiral stirring process, the Ca2+ and OH- ions in the lime water can react with the H+, heavy metals, and inorganic fluorides in the waste as follows: H+ reacts with the OH- in the lime water (H++OH-=H2O) for a neutralization reaction; the hydroxide solubility product constant Ksp of heavy metals (Class I: cadmium, lead; Class II: nickel, zinc, etc.) is extremely small, and such heavy metals are very easy to combine with OH- to form a precipitate; F- fully reacts with the Ca2+ in the lime water (F-+Ca2+=CaF2↓) to form a CaF2 precipitate that is hardly soluble in water; the wastes with the above characteristics are placed in the device, and after the lime water and the wastes are fully contacted and reacted during the spray stirring process, the effects of neutralizing acidity, removing heavy metals, and removing inorganic fluorides can be achieved. S3, stabilization and curing: the waste after the reaction is collected in an iron trough (12) and sent to a curing and curing workshop for 24 to 48 hours; S4. Sample testing: After curing, samples are taken to the laboratory for waste toxicity leaching testing based on the indicators required for entering the landfill; S5. Safe landfill: After testing all indicators of the waste and ensuring that they are fully qualified, safe landfill can be carried out.

Images