A zinc powder passivation process for water-based paint

Abstract

The invention discloses a zinc powder passivation process for water-based paint, relates to the technical field of zinc powder passivation, and comprises the following steps: step 1: preparing zinc powder, step 2: cooling the zinc powder in a sedimentation cooling bin, step 3: three-phase mixing of gas, liquid and solid, step 4: heat preservation of the zinc powder, and step 5: fluidized cooling of the zinc powder, wherein a negative pressure pipe generates negative pressure, and the zinc powder in the hopper enters a venturi pipe under the extraction of the negative pressure; at this time, a pump pumps a passivation liquid storage barrel into the venturi pipe, thereby forming a three-phase mixture of gas, liquid and solid; after the mixing is completed, stirring and mixing are performed in a mixer to fully increase the contact area between the passivation liquid and the zinc powder, and the mixer is heated at a heating temperature of 60-80°C and continuously stirred for 1 hour to improve the passivation effect of the zinc powder; then, the passivated zinc powder is heat-insulated at a temperature of 40-60°C for 1.5-2.2 hours; and finally, the zinc powder is cooled by fluidized cooling.

Description

Technical Field

[0001] The invention specifically relates to the technical field of zinc powder passivation, in particular to a zinc powder passivation process for water-based paint. Background Art

[0002] Zinc-rich paints are categorized into organic and inorganic zinc-rich paints. Organic zinc-rich paints often use epoxy resins, chlorinated rubber, vinyl resins, and polyurethane resins as film-forming bases. However, the organic film-forming materials of organic zinc-rich paints have poor electrical conductivity. Inorganic zinc-rich paints are further categorized into solvent-based and water-based. Water-based inorganic zinc-rich paints are composed of water-based inorganic silicate (sodium, potassium, lithium) resins, zinc powder, and additives.

[0003] Especially water-based paint, the so-called water-based paint is: paint that uses water as a solvent or a dispersion medium; in order to ensure that the surface activity of the paint is reduced after coating, thereby avoiding oxidation, we need to passivate the zinc powder. The passivated zinc powder has a certain antioxidant effect when used in paint. Summary of the Invention

[0004] The object of the present invention is to provide a zinc powder passivation process for water-based coatings to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A zinc powder passivation process for water-based paint comprises the following steps:

[0007] Step 1: Preparation of zinc powder: Place zinc ingots into a smelting furnace for melting, and then spray the molten zinc solution through a siphon spraying method to form zinc powder particles;

[0008] Step 2: Cooling the zinc powder in a sedimentation cooling bin;

[0009] Step 3: Three-phase mixing of gas, liquid and solid, using a three-phase mixing device to mix compressed air, zinc powder and passivation liquid and / or passivating agent, and then heating the three-phase mixing device to achieve passivation of the zinc powder; the three-phase mixing device includes a pipeline, a negative pressure pipe, a hopper, a pump, a passivation liquid storage barrel and a venturi tube; one end of the pipeline is connected to the compressed air source, and the other end is connected to the negative pressure pipe; the other end of the negative pressure pipe is connected to the venturi tube; the liquid inlet end of the pump is connected to the passivation liquid storage barrel through a hose, and the liquid outlet end of the pump is connected to the venturi tube through a pipeline;

[0010] Step 4: Insulation of zinc powder: Insulate the passivated zinc powder at a temperature of 40-60°C for 2 hours to fully passivate the zinc powder;

[0011] Step 5: Fluidized cooling of zinc powder. Fluidized cooling is to cool the zinc powder in a flowing state. The flow of zinc powder can also improve the dryness of the zinc powder.

[0012] As a further technical solution of the present invention, in step 3, the zinc powder passivation solution is one or more of alcohol and hydrogen peroxide.

[0013] As a further technical solution of the present invention, the passivating agent is one or more of a film-forming agent, an oxidizing agent, and a complexing agent.

[0014] As a further technical solution of the present invention, the film-forming agent is a trivalent chromium compound, which is one of a halide, a sulfate, a nitrate or an acetate.

[0015] As a further technical solution of the present invention, the oxidant is nitrate or permanganate.

[0016] As a further technical solution of the present invention, the complexing agent can form a relatively stable complex with zinc ions, and includes ammonium salts, acetates, oxalates, and organic carboxylates.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] In the present invention, when in use, external compressed air enters the negative pressure pipe through a pipeline, and under the blowing of the compressed air, the negative pressure pipe generates negative pressure, and the zinc powder in the hopper enters the venturi tube under the extraction of the negative pressure; at this time, the pump pumps the passivation liquid storage barrel into the venturi tube, thereby forming a three-phase mixture of gas, liquid and solid; after the mixing is completed, stirring and mixing are carried out in the mixer to fully increase the contact area between the passivation liquid and the zinc powder, and the mixer is heated at a heating temperature of 60-80°C and continuously stirred for 1 hour to improve the passivation effect of the zinc powder; then the passivated zinc powder is subjected to an insulation treatment at a temperature of 40-60°C for 1.5-2.2 hours; finally, it is cooled by fluidized cooling; fluidized cooling is to cool the zinc powder in a flowing state, and the zinc powder can also increase the dryness of the zinc powder during the flowing process, thereby obtaining passivated zinc powder for mixed use in water-based paint. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a zinc powder processing flow chart of the present invention.

[0020] Figure 2 It is a schematic structural diagram of the three-phase mixing equipment of the present invention.

[0021] In the figure, 1-pipeline, 2-negative pressure pipe, 3-hopper, 4-pump, 5-passivation liquid storage tank, 6-Venturi tube. DETAILED DESCRIPTION

[0022] 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 creative efforts are within the scope of protection of the present invention.

[0023] Please refer to the attached manual Figure 1-2 In an embodiment of the present invention, a zinc powder passivation process for water-based coatings comprises the following steps:

[0024] Step 1: Preparation of zinc powder: Place zinc ingots into a smelting furnace for melting, and then spray the molten zinc solution through a siphon spraying method to form zinc powder particles;

[0025] Step 2: Cooling the zinc powder in a sedimentation cooling bin;

[0026] Step 3: Three-phase mixing of gas, liquid and solid, using a three-phase mixing device to mix compressed air, zinc powder and passivation liquid and / or passivating agent, and then heating the three-phase mixing device to achieve passivation of the zinc powder; the three-phase mixing device includes a pipeline 1, a negative pressure pipe 2, a hopper 3, a pump 4, a passivation liquid storage barrel 5 and a venturi tube 6; one end of the pipeline 1 is connected to the compressed air source, and the other end is connected to the negative pressure pipe 2; the other end of the negative pressure pipe 2 is connected to the venturi tube 6; the liquid inlet end of the pump 4 is connected to the passivation liquid storage barrel 5 through a hose, and the liquid outlet end of the pump 4 is connected to the venturi tube 6 through a pipeline;

[0027] Step 4: Insulation of zinc powder: Insulate the passivated zinc powder at a temperature of 40-60°C for 2 hours to fully passivate the zinc powder;

[0028] Step 5: Fluidized cooling of zinc powder. Fluidized cooling is to cool the zinc powder in a flowing state. The flow of zinc powder can also improve the dryness of the zinc powder.

[0029] As a further technical solution of the present invention, in step 3, the zinc powder passivation solution is one or more of alcohol and hydrogen peroxide.

[0030] As a further technical solution of the present invention, the passivating agent is one or more of a film-forming agent, an oxidizing agent, and a complexing agent.

[0031] As a further technical solution of the present invention, the film-forming agent is a trivalent chromium compound, which is one of a halide, a sulfate, a nitrate or an acetate.

[0032] As a further technical solution of the present invention, the oxidant is nitrate or permanganate.

[0033] As a further technical solution of the present invention, the complexing agent can form a relatively stable complex with zinc ions, and includes ammonium salts, acetates, oxalates, and organic carboxylates.

[0034] How it works

[0035] During use, external compressed air enters the negative pressure pipe 2 through the pipe 1. Under the blowing of compressed air, the negative pressure pipe 2 generates negative pressure, and the zinc powder in the hopper 3 enters the venturi tube 6 under the extraction of negative pressure; at this time, the pump 4 pumps the passivation liquid storage barrel 5 into the venturi tube 6, thereby forming a three-phase mixture of gas, liquid and solid; after mixing, the mixture is stirred and mixed in the mixer to fully increase the contact area between the passivation liquid and the zinc powder, and the mixer is heated at a temperature of 60-80°C and stirred continuously for 1 hour to improve the passivation effect of the zinc powder; the passivated zinc powder is then kept warm at a temperature of 40-60°C for 1.5-2.2 hours; finally, it is cooled by fluidized cooling; fluidized cooling is to cool the zinc powder in a flowing state, and the zinc powder can also increase the dryness of the zinc powder during the flow process, thereby obtaining passivated zinc powder for mixed use in water-based paint.

[0036] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0037] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A zinc powder passivation process for water-based coatings, characterized in that: The following steps are involved: Step 1: Preparation of zinc powder: Place zinc ingots into a smelting furnace for melting, and then spray the molten zinc solution through a siphon spraying method to form zinc powder particles; Step 2: Cooling the zinc powder in a sedimentation cooling bin; Step 3: three-phase mixing of gas, liquid and solid, using a three-phase mixing device to mix compressed air, zinc powder and passivation liquid and / or passivating agent, and then heating the three-phase mixing device to achieve passivation treatment of the zinc powder; the three-phase mixing device includes a pipeline (1), a negative pressure pipe (2), a hopper (3), a pump (4), a passivation liquid storage barrel (5) and a venturi tube (6); one end of the pipeline (1) is connected to the compressed air source, and the other end is connected to the negative pressure pipe (2); the other end of the negative pressure pipe (2) is connected to the venturi tube (6); the liquid inlet end of the pump (4) is connected to the passivation liquid storage barrel (5) through a hose, and the liquid outlet end of the pump (4) is connected to the venturi tube (6) through a pipeline; Step 4: Insulation of zinc powder: Insulate the passivated zinc powder at a temperature of 40-60°C for 2 hours to fully passivate the zinc powder; Step 5: Fluidized cooling of zinc powder. Fluidized cooling is to cool the zinc powder in a flowing state. The flow of zinc powder can also improve the dryness of the zinc powder.

2. The zinc powder passivation process for water-based paint according to claim 1, wherein: The zinc powder passivation solution in step 3 is one or more of alcohol and hydrogen peroxide.

3. The zinc powder passivation process for water-based paint according to claim 1, wherein: Said step 3: the passivating agent is one or more of a film-forming agent, an oxidizing agent and a complexing agent.

4. The zinc powder passivation process for water-based paint according to claim 3, characterized in that: The film-forming agent is a trivalent chromium compound, which is one of halides, sulfates, nitrates or acetates.

5. The zinc powder passivation process for water-based paint according to claim 3, characterized in that: The oxidant is nitrate or permanganate.

6. The zinc powder passivation process for water-based paint according to claim 3, characterized in that: The complexing agent can form a relatively stable complex with zinc ions, and includes ammonium salt, acetate, oxalate, and organic carboxylate.

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