Corrosion-resistant coating for carbon thermal method arsenic reduction tank and preparation method of corrosion-resistant coating

Abstract

The invention relates to the technical field of corrosion-resistant coatings, in particular to a corrosion-resistant coating for a carbon thermal method arsenic reduction tank and a preparation method thereof.The corrosion-resistant coating adopts austenitic stainless steel 310S as the material of the arsenic reduction tank, the inner surface of the tank comprises a corrosion-resistant aluminum coating, and the corrosion-resistant aluminum coating and a metal material of the tank are provided with diffusion layers. The thickness of the diffusion layer is 2-10 [mu] m, and the aluminum element content of the diffusion layer is 2-5 wt%; a pure aluminum layer is arranged outside the diffusion layer, the thickness of the pure aluminum layer is 50-150 microns, and a compact aluminum oxide film is arranged outside the pure aluminum layer, and the thickness of the compact aluminum oxide film is 1-2 microns; the coating can react with high-temperature oxygen in the using process to form a compact oxidation film, and arsenic corrosion, chloride ion corrosion and sulfide corrosion in the high-temperature and high-oxygen environment can be hindered; meanwhile, the coating can form good bonding strength with a metal material of the tank body, and the service life of the coating is prolonged; and the clamping and rotating assembly is adopted, so that the machined part can be clamped and rotated.

Description

Technical Field

[0001] The invention relates to the technical field of corrosion-resistant coatings, and in particular to a corrosion-resistant coating for a carbothermal arsenic reduction tank and a preparation method thereof. Background Art

[0002] High-purity arsenic is widely used in medical equipment, aerospace and semiconductor materials. Carbothermal reduction is a common process for preparing high-purity arsenic. In this process, arsenic oxide powder and charcoal are heated to 700-800°C in a metal tank to react and produce metallic arsenic, carbon monoxide and carbon dioxide.

[0003] Arsenic oxide is mainly collected from the smelting flue gas of copper ore or lead ore by quenching; therefore, arsenic trioxide powder usually contains impurities such as sulfide, chloride, and fluoride. The decomposition products of these impurities will strongly corrode the arsenic reduction tank at high temperature, causing the tank to leak and lead to safety accidents;

[0004] Conventional arsenic carbon thermal reduction tanks are made of austenitic stainless steel and industrial pure titanium. However, under high temperature and high oxygen environment, the activated oxidation effect will aggravate the corrosion of the above materials. Therefore, the arsenic reduction tank needs to be replaced with a new tank after 4-8 days of service, which significantly reduces production efficiency and increases production costs. Summary of the invention

[0005] The problem solved by the present invention is to provide a corrosion-resistant coating for a carbothermal arsenic reduction tank and a preparation method thereof. During use, the coating reacts with high-temperature oxygen to form a dense oxide film, which can hinder arsenic corrosion, chloride ion corrosion and sulfide corrosion in a high-temperature and high-oxygen environment; at the same time, the coating can form a good bonding strength with the metal material of the tank body, thereby extending the service life of the coating.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a corrosion-resistant coating for a carbothermal arsenic reduction tank, the corrosion-resistant coating uses austenitic stainless steel 310S as the arsenic reduction tank body material, the inner surface of the tank body comprises a corrosion-resistant aluminum coating, the corrosion-resistant aluminum coating and the tank body metal material have a diffusion layer, the diffusion layer thickness is 2μm to 10μm, and the aluminum content of the diffusion layer is 2wt%-5wt%.

[0007] The outer part of the diffusion layer is a pure aluminum layer with a thickness of 50-150 μm, and the outer part of the pure aluminum layer is a dense aluminum oxide film with a thickness of 1-2 μm.

[0008] Preferably, a method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank comprises the following steps: step 1, preparation of a diffusion layer; step 2, preparation of a pure aluminum layer; step 3, testing of the corrosion-resistant coating;

[0009] In step 1, the diffusion layer is preferably prepared by physical vapor deposition;

[0010] In step 2, when preparing the pure aluminum outer layer, hot-dip aluminum and thermal diffusion methods are used for processing, and then the can body is placed in a heating furnace, and aluminum powder is evenly sprinkled on the can body, and aluminum is dipped at a temperature of 750-780°C for 40-50 minutes, and then kept in a diffusion furnace at 800±10°C for 5-10 hours, and then cooled to room temperature with the furnace; after being taken out of the furnace, a dense oxide film will naturally form on the outer side of the pure aluminum layer;

[0011] In step three, the stainless steel 310S / aluminum coating including the diffusion layer and the stainless steel 310S / aluminum coating not including the diffusion layer are placed into two detection chambers respectively, and arsenic oxide and charcoal materials are placed into the detection chambers, and then heated to 760°C for corrosion, and the corrosion time is 10 hours.

[0012] Preferably, in step 2, the heating furnace includes a furnace body, a clamping and rotating assembly, an aluminum powder sprinkling assembly and an observation window, the clamping and rotating assemblies are installed on the inner walls of both sides of the furnace body, the aluminum powder sprinkling assembly is installed in the furnace body, and an observation window is installed on one side of the furnace body.

[0013] Preferably, the clamping and rotating assembly includes a motor, a gear, a slide rail, a rotating ring, an inner gear ring, a support plate, a threaded hole, a clamping arc plate, a screw and a rotating handle. Slide rails are welded on the inner walls of both sides of the furnace body, and one side of the two slide rails is slidably connected to a rotating ring, an inner gear ring is fixedly connected to the rotating ring, and a gear is meshingly installed on the inner wall of the bottom end of the inner gear ring. Motors are inlaid and installed on the inner walls of both sides of the furnace body, and one end of the output shaft of the motor is fixedly connected to the outer wall of the gear. The rotating ring is symmetrically fixedly connected with a support plate, a threaded hole is provided on the support plate, a screw is installed in the threaded hole, a clamping arc plate is fixedly connected to the outer wall of one end of the screw, and a rotating handle is fixedly connected to the outer wall of the other end of the screw.

[0014] Preferably, the aluminum powder sprinkling assembly includes an extruded arc plate, a telescopic rod, a slider, a spring, a vibration box, a discharge hole and a slide groove. A vibration box is installed in the furnace body, and discharge holes are distributed at the bottom end of the vibration box. Slide grooves are opened on both sides of the vibration box, and sliders are slidably connected in the slide grooves. Telescopic rods are inlaid and connected on the inner walls of both sides of the furnace body, and the other end of the telescopic rod is fixedly connected to the outer wall of the slider. A spring is fixedly connected to the outer wall of one side of the slider, and the other end of the spring is fixedly connected to the inner wall of the furnace body. An extruded arc plate is fixedly connected to the rotating ring, and one side of the extruded arc plate is in contact with the outer wall of the vibration box.

[0015] Preferably, a display screen is inlaid on one side of the furnace body, and buttons are distributed and inlaid on one side of the furnace body.

[0016] Preferably, a placement opening is opened at the top of the furnace body, and a sealing cover plate is sealed in the placement opening.

[0017] Preferably, the spring is internally sleeved on the outer wall of the telescopic rod.

[0018] The beneficial effects of the present invention are as follows: the coating reacts with high-temperature oxygen to form a dense oxide film during use, which can prevent arsenic corrosion, chloride ion corrosion and sulfide corrosion in a high-temperature and high-oxygen environment; at the same time, the coating can form a good bonding strength with the metal material of the tank body, thereby extending the service life of the coating;

[0019] The clamping and rotating assembly is used to clamp and rotate the workpiece, which can easily sprinkle aluminum powder evenly on the workpiece, avoiding uneven aluminum powder scattering and improving the processing effect;

[0020] The aluminum powder sprinkling component is used to automatically and evenly sprinkle aluminum powder on the workpiece without manual assistance, thereby simplifying the sprinkling process and improving the use effect of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a corrosion morphology diagram of stainless steel containing a diffusion layer, wherein (a) is the microscopic morphology of the corrosion-resistant coating; (b) is the energy spectrum analysis result of the pure aluminum outer layer; (c) is the energy spectrum analysis result of the diffusion layer; (d) is the energy spectrum analysis result diagram of the substrate;

[0022] Figure 2 The present invention is a corrosion morphology diagram of stainless steel that does not contain a diffusion layer;

[0023] Figure 3 This is a corrosion comparison diagram of conventional stainless steel of the present invention;

[0024] Figure 4 This is a corrosion comparison diagram of the coated stainless steel of the present invention;

[0025] Figure 5 It is the overall three-dimensional structural diagram of the heating furnace of the present invention;

[0026] Figure 6 It is a front view cutaway structural diagram of the heating furnace of the present invention;

[0027] Figure 7 It is a top view cutaway structural diagram of the heating furnace of the present invention;

[0028] Figure 8 It is a three-dimensional internal structure diagram of the heating furnace of the present invention.

[0029] Legend:

[0030] 1. Furnace body; 2. Clamping and rotating assembly; 3. Aluminum powder sprinkling assembly; 4. Observation window; 5. Display screen; 6. Button; 7. Placement port; 8. Sealing cover plate; 201. Motor; 202. Gear; 203. Slide rail; 204. Rotating ring; 205. Internal gear ring; 206. Support plate; 207. Threaded hole; 208. Clamping arc plate; 209. Screw rod; 2010. Rotating handle; 301. Extrusion arc plate; 302. Telescopic rod; 303. Sliding block; 304. Spring; 305. Vibration box; 306. Discharge hole; 307. Slide groove. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0032] Embodiment 1

[0033] See also Figure 3-4 A corrosion-resistant coating for a carbothermal arsenic reduction tank. The corrosion-resistant coating uses austenitic stainless steel 310S as the arsenic reduction tank body material. The inner surface of the tank body includes a corrosion-resistant aluminum coating. The corrosion-resistant aluminum coating and the tank body metal material have a diffusion layer. The diffusion layer has a thickness of 2μm to 10μm, and the aluminum content of the diffusion layer is 2wt%-5wt%.

[0034] The outside of the diffusion layer is a pure aluminum layer with a thickness of 50-150 μm, and the outside of the pure aluminum layer is a dense aluminum oxide film with a thickness of 1-2 μm.

[0035] Hanging plate experimental data: conventional S310 stainless steel plate and S310 stainless steel plate with the coating of the present invention are respectively made into open cans with a diameter of 660mm and a height of 1360mm, and the thickness of the steel plate is uniformly 8mm; then As2O3 powder is piled in the can, and the pile height is 60% of the total height of the can; then a grid is placed on the can, and charcoal is piled on the grid; and the can is placed in a large crucible wound with a resistance wire, and the heating temperature is about 700-750℃; reference Figure 3 and Figure 4 The morphologies of the inner surfaces of the steel plates after heating for 8 hours are shown respectively; it can be seen that severe uniform corrosion occurs on the surface of the conventional S310 stainless steel plate, while no obvious corrosion is found on the coating of the present invention.

[0036] Embodiment 2

[0037] See also Figure 1-2, a method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank, comprising the following steps: step one, preparation of a diffusion layer; step two, preparation of a pure aluminum layer; step three, detection of the corrosion-resistant coating;

[0038] In step 1, the diffusion layer is preferably prepared by physical vapor deposition;

[0039] In step 2, when preparing the pure aluminum outer layer, hot-dip aluminum and thermal diffusion methods are used for processing, and then the can body is placed in a heating furnace, and aluminum powder is evenly sprinkled on the can body, and aluminum is dipped at a temperature of 750-780°C for 40-50 minutes, and then kept in a diffusion furnace at 800±10°C for 5-10 hours, and then cooled to room temperature with the furnace; after being taken out of the furnace, a dense oxide film will naturally form on the outer side of the pure aluminum layer;

[0040] In step three, the stainless steel 310S / aluminum coating including the diffusion layer and the stainless steel 310S / aluminum coating not including the diffusion layer are placed into two detection chambers respectively, and arsenic oxide and charcoal materials are placed into the detection chambers, and then heated to 760°C for corrosion, and the corrosion time is 10 hours.

[0041] Embodiment 3

[0042] See also Figures 5 to 8 In step 2, the heating furnace includes a furnace body 1, a clamping and rotating assembly 2 and an aluminum powder sprinkling assembly 3. The clamping and rotating assemblies 2 are installed on the inner walls of both sides of the furnace body 1, the aluminum powder sprinkling assembly 3 is installed in the furnace body 1, and an observation window 4 is installed on one side of the furnace body 1; a display screen 5 is inlaid on one side of the furnace body 1, and buttons 6 are distributed and inlaid on one side of the furnace body 1. The furnace body 1 is operated by the buttons 6, and then the data in the furnace body 1 is displayed; a placement opening 7 is opened at the top of the furnace body 1, and a sealing cover plate 8 is sealed and connected in the placement opening 7. The workpiece is placed into the furnace body 1 through the placement opening 7. After the workpiece is placed, the sealing cover plate 8 is used to seal and fix the placement opening 7;

[0043] The clamping rotating assembly 2 includes a motor 201, a gear 202, a slide rail 203, a rotating ring 204, an inner gear ring 205, a support plate 206, a threaded hole 207, a clamping arc plate 208, a screw rod 209 and a rotating handle 2010. The slide rails 203 are welded on the inner walls of both sides of the furnace body 1. The rotating ring 204 is slidably connected to one side of the two slide rails 203. The inner gear ring 205 is fixedly connected to the rotating ring 204. The inner wall of the bottom end of the inner gear ring 205 is meshed with a Gear 202, motors 201 are embedded and installed on the inner walls on both sides of the furnace body 1, and one end of the output shaft of the motor 201 is fixedly connected to the outer wall of the gear 202, and a support plate 206 is symmetrically fixedly connected to the rotating ring 204, and a threaded hole 207 is opened on the support plate 206. A screw rod 209 is installed in the threaded hole 207, and a clamping arc plate 208 is fixedly connected to the outer wall of one end of the screw rod 209, and a rotating handle 2010 is fixedly connected to the outer wall of the other end of the screw rod 209.

[0044] Working principle: first, place the workpiece into the furnace body 1 through the placement port 7, then turn the rotating handle 2010 to rotate the screw rod 209 on the clamping arc plate 208, and then, under the action of the threaded hole 207 on the support plate 206, the clamping arc plate 208 clamps and fixes the workpiece, and then the sealing cover plate 8 seals and fixes the placement port 7, then start the motor 201 to rotate the gear 202, and then, under the action of the inner gear ring 205, the rotating ring 204 slowly rotates along the slide rail 203, so that the aluminum powder is evenly sprinkled on the tank body, the workpiece can be clamped, and the workpiece can be rotated, so that the aluminum powder can be evenly sprinkled on the workpiece, avoiding uneven aluminum powder spillage and improving the processing effect.

[0045] Embodiment 4

[0046] See also Figure 6 and Figure 8The aluminum powder sprinkling assembly 3 includes an extruded arc plate 301, a telescopic rod 302, a slider 303, a spring 304, a vibration box 305, a discharge hole 306 and a slide groove 307. The vibration box 305 is installed in the furnace body 1. The discharge hole 306 is distributed at the bottom of the vibration box 305. The slide grooves 307 are opened on both sides of the vibration box 305. The slider 303 is slidably connected in the slide groove 307. The inner walls of both sides of the furnace body 1 are inlaid with telescopic rods 302, and the other end of the telescopic rods 302 is fixed to the outer wall of the slider 303. One end of the slider 303 A spring 304 is fixedly connected to the side outer wall, and the other end of the spring 304 is fixedly connected to the inner wall of the furnace body 1. An extrusion arc plate 301 is fixedly connected to the rotating ring 204, and one side of the extrusion arc plate 301 is in contact with the outer wall of the vibration box 305; the spring 304 is internally sleeved on the outer wall of the telescopic rod 302. When the extrusion arc plate 301 is separated from the vibration box 305, the vibration box 305 is reciprocated along the telescopic rod 302 under the action of the spring 304, and then the aluminum powder is evenly sprinkled on the workpiece through the discharge hole 306.

[0047] When aluminum powder needs to be sprinkled on the workpiece, the slide groove 307 on the vibration box 305 is engaged with the slider 303 on the telescopic rod 302, and then the motor 201 is started to rotate the gear 202. Then, under the action of the inner gear ring 205, the rotating ring 204 is slowly rotated along the slide rail 203. Then, the vibration box 305 is squeezed by the extrusion arc plate 301, so that the extrusion arc plate 301 moves along the telescopic rod 302. When the extrusion arc plate 301 is separated from the vibration box 305, the vibration box 305 is reciprocated along the telescopic rod 302 under the action of the spring 304. Then, the aluminum powder is evenly sprinkled on the workpiece through the discharge hole 306. The aluminum powder can be automatically and evenly sprinkled on the workpiece without manual assistance, thereby simplifying the sprinkling process and improving the use effect of the equipment.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A corrosion-resistant coating for a carbothermal arsenic reduction tank, characterized in that: The corrosion-resistant coating uses austenitic stainless steel 310S as the arsenic reduction tank material. The inner surface of the tank body includes a corrosion-resistant aluminum coating. The corrosion-resistant aluminum coating and the tank body metal material have a diffusion layer with a thickness of 2μm to 10μm. The aluminum content of the diffusion layer is 2wt%-5wt%.

2. The corrosion-resistant coating for a carbothermal arsenic reduction tank according to claim 1, characterized in that: The outer part of the diffusion layer is a pure aluminum layer with a thickness of 50-150 μm, and the outer part of the pure aluminum layer is a dense aluminum oxide film with a thickness of 1-2 μm.

3. A method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank, characterized in that: The method comprises the following steps: step 1, preparation of a diffusion layer; step 2, preparation of a pure aluminum layer; step 3, detection of a corrosion-resistant coating; In step 1, the diffusion layer is preferably prepared by physical vapor deposition; In step 2, when preparing the pure aluminum outer layer, hot-dip aluminum and thermal diffusion methods are used for processing, and then the can body is placed in a heating furnace, and aluminum powder is evenly sprinkled on the can body, and aluminum is dipped at a temperature of 750-780°C for 40-50 minutes, and then kept in a diffusion furnace at 800±10°C for 5-10 hours, and then cooled to room temperature with the furnace; after being taken out of the furnace, a dense oxide film will naturally form on the outer side of the pure aluminum layer; In step three, the stainless steel 310S / aluminum coating including the diffusion layer and the stainless steel 310S / aluminum coating not including the diffusion layer are placed into two detection chambers respectively, and arsenic oxide and charcoal materials are placed into the detection chambers, and then heated to 760°C for corrosion, and the corrosion time is 10 hours.

4. The method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank according to claim 3, characterized in that: In the step 2, the heating furnace comprises a furnace body (1), a clamping and rotating assembly (2), an aluminum powder sprinkling assembly (3) and an observation window (4); the clamping and rotating assemblies (2) are installed on the inner walls of both sides of the furnace body (1); the aluminum powder sprinkling assembly (3) is installed in the furnace body (1); and the observation window (4) is installed on one side of the furnace body (1).

5. The method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank according to claim 4, characterized in that: The clamping rotating assembly (2) comprises a motor (201), a gear (202), a slide rail (203), a rotating ring (204), an inner gear ring (205), a support plate (206), a threaded hole (207), a clamping arc plate (208), a screw rod (209) and a rotating handle (2010). The slide rails (203) are welded on the inner walls of both sides of the furnace body (1), one side of the two slide rails (203) is slidably connected to the rotating ring (204), the inner gear ring (205) is fixedly connected inside the rotating ring (204), and a meshing mounting is provided on the inner wall of the bottom end of the inner gear ring (205). A gear (202) is installed, and motors (201) are embedded and installed on the inner walls of both sides of the furnace body (1), and one end of the output shaft of the motor (201) is fixedly connected to the outer wall of the gear (202). A support plate (206) is symmetrically fixedly connected to the rotating ring (204), and a threaded hole (207) is opened on the support plate (206). A screw rod (209) is installed in the threaded hole (207), and a clamping arc plate (208) is fixedly connected to the outer wall of one end of the screw rod (209), and a rotating handle (2010) is fixedly connected to the outer wall of the other end of the screw rod (209).

6. The method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank according to claim 5, characterized in that: The aluminum powder sprinkling assembly (3) comprises an extruded arc plate (301), a telescopic rod (302), a slider (303), a spring (304), a vibration box (305), a discharge hole (306) and a slide groove (307). The furnace body (1) is provided with a vibration box (305). The bottom end of the vibration box (305) is provided with a discharge hole (306). Both sides of the vibration box (305) are provided with a slide groove (307). The slide groove (307) is slidably connected with the slider (303). ), telescopic rods (302) are embedded and connected on both sides of the inner wall of the furnace body (1), and the other end of the telescopic rods (302) is fixedly connected to the outer wall of the slider (303), a spring (304) is fixedly connected to one side of the outer wall of the slider (303), and the other end of the spring (304) is fixedly connected to the inner wall of the furnace body (1), and the rotating ring (204) is fixedly connected to an extrusion arc plate (301), and one side of the extrusion arc plate (301) is in contact with the outer wall of the vibration box (305).

7. The method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank according to claim 4, characterized in that: A display screen (5) is inlaid and installed on one side of the furnace body (1), and buttons (6) are distributed and inlaid and installed on one side of the furnace body (1).

8. The method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank according to claim 4, characterized in that: A placement opening (7) is provided at the top of the furnace body (1), and a sealing cover plate (8) is sealedly connected inside the placement opening (7).

9. The method for preparing a corrosion-resistant coating for a carbothermal arsenic reduction tank according to claim 5, characterized in that: The spring (304) is sleeved on the outer wall of the telescopic rod (302).

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