Electrolytic phosphating replenishing composition, electrolytic phosphating replenishing tablet prepared by using phosphating waste residue, method and application thereof

Abstract

The present application relates to the technical field of phosphating waste residue utilization, and particularly to an electrolytic phosphating replenishing composition prepared from phosphating waste residue, an electrolytic phosphating replenishing tablet, a method and application thereof. The present application discloses an electrolytic phosphating replenishing composition prepared from phosphating waste residue, which comprises the following components in percentage by weight: 1-2% of a binder, 5-10% of an organic acid, 15-30% of sodium bicarbonate, 2-8% of a lubricating release agent, and the balance of phosphating residue. The present application converts phosphating waste residue generated by traditional immersion phosphating into an electrolytic phosphating replenishing tablet, and realizes the resource utilization of hazardous waste, reduces environmental pollution and resource waste by using the electrolytic phosphating replenishing composition prepared from phosphating waste residue, the electrolytic phosphating replenishing tablet, the method and application thereof.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of utilization of phosphating waste residue, and in particular to an electrolytic phosphating replenishing composition prepared from phosphating waste residue, an electrolytic phosphating replenishing tablet and a method and application thereof. BACKGROUND

[0002] Phosphating treatment, as one of the important processes for metal surface treatment, is widely used in the automobile, household appliance, and machinery manufacturing industries. Traditional immersion phosphating technology forms a protective phosphating film on the metal material by immersing the metal material in a specific chemical solution, thereby improving the corrosion resistance, lubricity, and wear resistance of the metal material. However, a certain amount of phosphating residue is inevitably generated during the immersion phosphating process. These waste residues contain elements such as phosphorus, zinc, iron, and nickel, and are classified as hazardous waste, which is toxic and corrosive. If the phosphating residue is not properly treated, it will cause serious environmental pollution.

[0003] In recent years, electrolytic phosphating has gradually attracted attention as a new type of phosphating method. Compared with traditional immersion phosphating, electrolytic phosphating directly deposits phosphate crystals on the metal surface through an electrochemical reaction, which not only realizes residue-free phosphating, but also precisely controls the film formation process, resulting in a more uniform and dense phosphating film layer, significantly improving the protective performance and decorative effect of the metal material. For electrolytic phosphating, replenishing agents need to be added regularly to maintain the stability of the film-forming ion concentration in the bath. Due to the problems of easy moisture absorption, low solubility, and easy agglomeration of powder replenishing agents, the replenishing operation is inconvenient, so the existing replenishing agents are mostly in liquid form. However, liquid replenishing agents contain a large amount of acid agents and solvents, increasing the logistics cost and the risk of environmental pollution.

[0004] Currently, there is no relevant report on the use of phosphating residue as a replenishing agent in the electrolytic phosphating process. Therefore, the present application discloses an electrolytic phosphating replenishing composition prepared from phosphating waste residue, an electrolytic phosphating replenishing tablet and a method and application thereof by converting the phosphating waste residue generated from traditional immersion phosphating into an electrolytic phosphating replenishing tablet. SUMMARY

[0005] The present application discloses an electrolytic phosphating replenishing composition prepared from phosphating waste residue, an electrolytic phosphating replenishing tablet and a method and application thereof by converting the phosphating waste residue generated from traditional immersion phosphating into an electrolytic phosphating replenishing tablet, which realizes the resource utilization of hazardous waste and reduces environmental pollution and resource waste.

[0006] The object of the present application is achieved by the following technical solutions:

[0007] In a first aspect of the present application, an electrolytic phosphating replenishing composition prepared from phosphating waste residue is provided, which comprises the following components by weight percentage:

[0008] Binder 1-2%

[0009] Organic acid 5-10%

[0010] Sodium bicarbonate 15-30%

[0011] Lubricating release agent 2-8%

[0012] The balance is phosphating residue.

[0013] In some embodiments, the binder is any one or more of polyvinylpyrrolidone, hydroxypropyl methylcellulose, sodium carboxymethylcellulose.

[0014] In some embodiments, the organic acid is any one or more of citric acid, malic acid, tartaric acid, and succinic acid.

[0015] In some embodiments, the lubricating release agent is any one or more of polyethylene glycol 4000, polyethylene glycol 6000, polyoxyethylene ether.

[0016] In some embodiments, the phosphating residue is from an immersion phosphating process.

[0017] In a second aspect of the present application, there is provided a phosphating replenishment tablet, comprising the electrolytic phosphating replenishment composition of the first aspect.

[0018] In a third aspect of the present application, there is provided a method for preparing the electrolytic phosphating replenishment tablet of the second aspect, comprising the following steps:

[0019] 1) pretreating the phosphating residue;

[0020] 2) mixing the pretreated phosphating residue with a binder, an organic acid, sodium bicarbonate, and a lubricating release agent to obtain an electrolytic phosphating replenishment composition;

[0021] 3) compressing the electrolytic phosphating replenishment composition to obtain an electrolytic phosphating replenishment tablet;

[0022] In step 1), the pretreatment process is:

[0023] The phosphating residue is added to phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5 to obtain a phosphating residue solid-liquid mixture;

[0024] Zinc oxide is added to the phosphating residue solid-liquid mixture to adjust the pH value of the phosphating residue solid-liquid mixture to 7, and then filtered to obtain a phosphating residue wet residue;

[0025] The phosphating residue wet residue is dried to obtain a phosphating residue powder.

[0026] In some embodiments, in step 3), the pressure of the pressing is controlled at 5-15 MPa, and the thickness of the electrolytic phosphating replenishment tablet is 4-6 mm.

[0027] In a fourth aspect of the present application, the electrolytic phosphating replenishment tablet prepared by the method of the third aspect or the electrolytic phosphating replenishment tablet of the second aspect is applied to an electrolytic phosphating process.

[0028] In some embodiments, in the electrolytic phosphating process, the electrolytic phosphating replenishment tablet is added to the electrolyte, and the composition of the electrolyte is monitored.

[0029] The present application has the following beneficial effects:

[0030] 1. The electrolytic phosphating replenishment tablet of the present application realizes the resource utilization of hazardous waste by converting the phosphating waste slag generated by traditional immersion phosphating into the electrolytic phosphating replenishment tablet, thereby reducing environmental pollution and resource waste.

[0031] 2. The electrolytic phosphating replenishment tablet of the present application can effectively maintain the balance of film-forming ions in the electrolytic phosphating bath, thereby realizing the uniformity and compactness of the electrolytic phosphating film layer and improving the quality of the electrolytic phosphating film layer.

[0032] 3. The electrolytic phosphating replenishment tablet of the present application reduces the use of water and solvents, and is in solid form during transportation and storage, thereby reducing the volume and weight of the product compared to liquid preparations, and thereby reducing logistics costs and storage space.

[0033] 4. The electrolytic phosphating replenishment tablet of the present application avoids the problems of easy moisture absorption, low solubility, and easy agglomeration of powder preparations during the replenishment operation of the electrolytic phosphating bath, thereby improving the solubility and dispersibility of the replenishment agent in the electrolytic phosphating bath.

[0034] 5. The electrolytic phosphating replenishment tablet of the present application has the characteristics of accurate dosage, stable quality, and convenient storage and transportation of solid preparations, making the replenishment process of the electrolytic phosphating process more convenient, and improving the production efficiency and operational convenience of the electrolytic phosphating process. BRIEF DESCRIPTION OF DRAWINGS

[0035] The present application will be further described below in conjunction with the drawings and examples.

[0036] Figure 1 The metallographic microscope photograph of the phosphating film obtained in Example 3;

[0037] Figure 2 The metallographic microscope photograph of the phosphating film obtained in Comparative Example 1;

[0038] Figure 3 A metallographic microscope photograph of the phosphating film obtained in Comparative Example 6. DETAILED DESCRIPTION

[0039] For the convenience of those skilled in the art, the present application is further illustrated below with examples, and the content mentioned in the examples is not a limitation of the present application.

[0040] As used herein, "and / or" includes the term "and", "or" and any one or more associated listed terms. The terms used herein are only used to describe specific embodiments, and are not intended to limit the present application. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It is further understood that "comprising" as used in the specification, specifies the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0041] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0042] The exemplary applications described herein can suitably lack any one or more of the optional limitations described herein. Thus, the terms "comprise", "include", "contain", and the like, are to be construed in an open, inclusive and non-limiting sense. Furthermore, the use of "including" and "comprising" and variations thereof, does not limit the terms to the inclusion of only the recited items, but rather allow for the possibility of including additional items not expressly listed or inherent to such terms. Additionally, the terms of expression used herein are used as description, not limitation, and it is not intended that any equivalent characteristics be excluded by the use of these terms of expression, but only that part of the characteristics are described, but according to the right, various modifications are possible within the scope of the present application. Therefore, although the present application has been specifically disclosed by preferred embodiments and optional features, modifications to embody the present application disclosed herein can be recorded by those skilled in the art, and such modifications and changes will be considered within the scope of the present application.

[0043] The raw materials or reagents used in the examples and comparative examples of the present application are purchased from mainstream manufacturers in the market. If the manufacturer is not specified or the concentration is not specified, it is an analytical pure grade raw material or reagent that can be obtained conventionally, and there is no particular limitation as long as it can play the expected role. The instruments and equipment used in the examples are purchased from major manufacturers in the market, as long as they can play the expected role, and there is no particular limitation. If the specific technology or condition is not specified in the examples, it is carried out according to the technology or condition described in the literature in the art or according to the product instruction manual.

[0044] In the process practice of electrolytic phosphating, it is necessary to regularly add replenishers containing phosphorus, zinc, iron and other elements to the electrolytic phosphating tank solution to maintain normal use of the process. Because the powder preparation of film-forming cations has the disadvantages of easy moisture absorption, low solubility, easy agglomeration when added to the tank solution, etc., the electrolytic phosphating replenishers on the market generally adopt the form of liquid. Moreover, in order to maintain the sufficient dissolution of zinc, iron, manganese and other film-forming cations, a large amount of acid agent such as phosphoric acid and nitric acid needs to be additionally compounded, so that the electrolytic phosphating replenisher has high acidity. During the continuous replenishment and use process, the free acid of the electrolytic phosphating solution gradually increases, which further leads to ion imbalance of the electrolytic phosphating solution and poor application effect of the film layer. In addition, in order to maintain the non-precipitation of other effective components in the electrolytic phosphating liquid replenisher, the replenisher formula also contains a large amount of water and solvent, which do not participate in electrolytic phosphating but occupy a large amount of mass and volume, which also leads to high logistics cost. The main components of the current phosphating slag include phosphorus, zinc, iron, nickel and other elements, which are classified as HW17 surface treatment waste in the National Hazardous Waste List, and have toxicity and corrosivity, which will cause environmental pollution if directly discharged. At present, the common treatment methods include neutralization precipitation, adsorption method, ion exchange method, etc., and the resource utilization process is complex, and the harmless disposal cost is high. If these phosphating slags are simply treated as hazardous waste, not only the safety hidden danger will be increased, but also the resource will be greatly wasted.

[0045] Therefore, the electrolytic phosphating replenishing composition prepared by using the phosphating waste slag provided by the present application comprises the following components in weight percentage:

[0046] Binder 1-2%

[0047] Organic acid 5-10%

[0048] Sodium bicarbonate 15-30%

[0049] Lubricating release agent 2-8%

[0050] The balance is phosphating slag.

[0051] Specifically, the binder is any one or several of polyvinylpyrrolidone, hydroxypropyl methyl cellulose and sodium carboxymethyl cellulose.

[0052] In the present application, the role of the binder is to ensure that the phosphating waste slag powder can be effectively bonded to form tablets with certain strength and shape. The selection of the binder such as polyvinylpyrrolidone, hydroxypropyl methyl cellulose and sodium carboxymethyl cellulose can provide good bonding performance, so that the tablets can stably release effective components in the subsequent electrolytic phosphating process.

[0053] In some embodiments, the weight percentage of the binder is 1-2%, for example, the weight percentage of the binder is any value of 1%, 1.2%, 1.5%, 1.8%, 2%, and can be within 1-2% (including the end values). The weight percentage of the binder is 1-2%, which can ensure that the tablet has sufficient mechanical strength without being too hard or too brittle. If the weight percentage of the binder is less than 1%, it may not provide sufficient bonding force, resulting in a fragile tablet; if the weight percentage of the binder exceeds 2%, it may cause the tablet to be too hard, affecting its disintegration rate.

[0054] Specifically, the organic acid is any one or any combination of citric acid, malic acid, tartaric acid, and succinic acid.

[0055] In this application, the role of the organic acid is to effectively buffer the free acid in the phosphating solution, realize precise control of the electrolytic phosphating tank solution acidity, and ensure that the electrochemical state in the electrolytic phosphating process is optimal. Acidity control is a key factor affecting the uniformity and quality of the film layer. Through the combination of multiple organic acids such as citric acid, malic acid, tartaric acid, and succinic acid, the microstructure of the electrolytic phosphating film layer can be optimized, the electrolytic phosphating effect can be enhanced, the porosity and crack phenomenon can be reduced, and thus the appearance quality of the electrolytic phosphating film layer can be improved.

[0056] In some embodiments, the weight percentage of the organic acid is 5-10%, for example, the weight percentage of the organic acid is any value of 5%, 6%, 7%, 8%, 9%, 10%, and can be within 5-10% (including the end values). The weight percentage of the organic acid is 5-10%, which can maintain appropriate acidity, promote film formation reaction, and improve film layer quality. If the weight percentage of the organic acid is less than 5%, it may not be enough to adjust the acidity, affecting the uniformity and density of the film layer; if the weight percentage of the organic acid exceeds 10%, it may cause excessive acidification, damaging the film layer structure.

[0057] Specifically, the lubricating release agent is any one or any combination of polyethylene glycol 4000, polyethylene glycol 6000, and polyoxyethylene ether.

[0058] In this application, the role of the lubricating release agent is to reduce the friction between the tablet and the mold, facilitate the molding and demolding of the tablet, smoothly discharge and tablet during the tabletting process, and reduce the sticking. Reasonable use of lubricating release agents such as polyethylene glycol 4000, polyethylene glycol 6000, and polyoxyethylene ether can ensure that the tablet has good fluidity and formability during production, effectively reduce the friction between the tablet and the mold, ensure the smoothness of the tablet during molding and demolding, and thus improve the production efficiency and product quality.

[0059] In some embodiments, the lubricating release agent has a weight percentage of 2-8%, for example, the lubricating release agent has a weight percentage of any value of 2%, 3%, 4%, 5%, 6%, 7%, 8%, and the weight percentage of the lubricating release agent can be within 2-8% (including the end value). The weight percentage of the lubricating release agent is 2-8% to ensure good fluidity and formability. If the weight percentage of the lubricating release agent is less than 2%, the release is difficult and easy to stick; if the weight percentage of the lubricating release agent is more than 8%, it may cause the tablet surface to be too smooth, affecting the subsequent processing.

[0060] Specifically, the phosphating residue is from the immersion phosphating process.

[0061] In this application, the phosphating residue powder is derived from the waste residue generated in the traditional immersion phosphating process. After treatment, the effective ingredients in the phosphating residue powder are preserved, realizing the resource utilization of waste residue, reducing environmental pollution, and at the same time, this recycling strategy provides necessary replenishing agent for the electrolytic phosphating process, further enhancing the practical value and environmental protection significance of the application.

[0062] Specifically, sodium bicarbonate acts as a disintegrating agent, and its mechanism of action is to react with organic acid and free acid in the electrolytic phosphating tank solution to generate carbon dioxide gas. This reaction occurs rapidly when the tablet contacts the electrolytic phosphating tank solution, allowing the tablet to rapidly disintegrate. The electrolytic phosphating replenishing tablet itself is dry and contains no water. When the tablet is put into the electrolytic phosphating tank solution, sodium bicarbonate and organic acid ionize under the combined action of water and free acid in the electrolytic phosphating tank solution, react, and produce a large amount of carbon dioxide, causing the tablet to rapidly disintegrate and melt. The gas bubbles generated by disintegration also make the tablet roll up and down in the electrolytic phosphating tank solution, accelerating its disintegration and melting, thereby rapidly releasing the effective ingredients in the tablet, improving the solubility and dispersibility of the replenishing tablet.

[0063] In some embodiments, the weight percentage of sodium bicarbonate is 15-30%, for example, the weight percentage of sodium bicarbonate is any value of 15%, 16%, 17%, 18%, 19%, 20%, and the weight percentage of sodium bicarbonate can be within 15-30% (including the end value). The weight percentage of sodium bicarbonate is 15-30% to ensure rapid disintegration. If the weight percentage of sodium bicarbonate is less than 15%, the disintegration speed may not be fast enough, affecting the replenishing efficiency; if the weight percentage of sodium bicarbonate is more than 30%, it may cause unnecessary bubble generation, interfering with the electrolysis process.

[0064] In a second aspect of the present application, a dephosphorization replenishing tablet is provided, comprising the electrolytic phosphating replenishing composition of the first aspect.

[0065] In a third aspect of the present application, a method for preparing the electrolytic phosphating replenishing tablet of the second aspect is provided, comprising the following steps:

[0066] 1) pretreating phosphating residues;

[0067] 2) mixing the pretreated phosphating residues with a binder, an organic acid, sodium bicarbonate and a lubricating release agent to obtain an electrolytic phosphating replenishing composition;

[0068] 3) pressing the electrolytic phosphating replenishing composition to obtain an electrolytic phosphating replenishing tablet;

[0069] In step 1), the pretreatment process is as follows:

[0070] The phosphating residues are put into phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5 to obtain a phosphating residue solid-liquid mixture;

[0071] Zinc oxide is added to the phosphating residue solid-liquid mixture to adjust the pH value of the phosphating residue solid-liquid mixture to 7, and then the mixture is filtered to obtain phosphating residue wet residue;

[0072] The phosphating residue wet residue is dried to obtain phosphating residue powder.

[0073] In some embodiments, in step 3), the pressing pressure is controlled at 5-15 MPa, and the thickness of the electrolytic phosphating replenishing tablet is 4-6 mm.

[0074] Specifically, the preparation method of the electrolytic phosphating replenishing tablet comprises the following steps:

[0075] S101. The phosphating residues are put into dilute phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5, the temperature is raised to 40-60°C, and stirring is continued for 2 h to obtain a phosphating residue solid-liquid mixture.

[0076] S102. Zinc oxide is added to the phosphating residue solid-liquid mixture in small amounts and multiple times, the pH value of the phosphating residue solid-liquid mixture is adjusted to 7, the temperature is raised to 60-80°C, and stirring is continued for 4 h. The mixture is filtered while hot to obtain phosphating residue wet residue;

[0077] S103. The phosphating residue wet residue is put into a drying machine for drying at a temperature of 120°C for 6 h to obtain phosphating residue powder;

[0078] S104. The raw materials are prepared according to the weight of the corresponding raw materials in the weight percentage, and are respectively stored in a dryer to obtain raw material dry powder, and the moisture content of the raw material dry powder is within 1%;

[0079] S105. The dried binder, organic acid, sodium bicarbonate, lubricating release agent and phosphating residue powder are added to a flour mill, and the grinding fineness is 80-100 mesh. The mixture is thoroughly ground and mixed, sieved through a sieve with a mesh size of 80-120 mesh to obtain an electrolytic phosphating replenishing powder;

[0080] S106. The electrolytic phosphating replenishing powder is put into a tablet press, and tablets are pressed with a pressure controlled at 5-15 MPa and a thickness of 4-6 mm, to obtain electrolytic phosphating replenishing tablets.

[0081] In the present application, the phosphating waste residue is put into dilute phosphoric acid to obtain a phosphating residue solid-liquid mixture. The purpose of this step is to make the impurities in the phosphating waste residue fully react with the dilute phosphoric acid to form a uniform solid-liquid mixture, providing a stable reaction matrix for subsequent processing.

[0082] In the present application, a small amount of zinc oxide is added to the phosphating residue solid-liquid mixture multiple times to adjust the pH of the phosphating residue solid-liquid mixture. The purpose of this step is to adjust the pH value by gradually adding zinc oxide to promote the consumption of free acid in the solid-liquid mixture, improve the purity and performance of the product, and add a small amount of zinc oxide each time to ensure that the reaction proceeds fully while the pH value is accurately controlled.

[0083] In the present application, the phosphating residue wet residue is put into a dryer for drying to obtain phosphating residue powder. The purpose of this step is to remove the moisture in the phosphating residue wet residue to obtain dry powder, facilitating subsequent mixing and processing.

[0084] In the present application, the raw materials are prepared according to the weight of the corresponding raw materials in the weight percentage, and are stored in dryers respectively to obtain raw material dry powder. The purpose of this step is to ensure that each raw material remains dry to prevent moisture absorption and avoid tablet disintegration before use, affecting product quality.

[0085] In the present application, the raw material dry powder pre-drying treatment is carried out at a temperature not exceeding 60°C, and the raw material dry powder stored in the dryer needs to be turned over regularly. The purpose of this step is to avoid thermal decomposition of the raw materials, prevent caking, and ensure uniform drying.

[0086] In the present application, the dry binder, organic acid, sodium bicarbonate, lubricating release agent, and phosphating residue powder are added to a pulverizer, thoroughly ground and mixed uniformly, and sieved to obtain electrolytic phosphating replenishing powder. The purpose of this step is to prepare powder with uniform particle size and consistent composition, providing qualified raw materials for the tablet pressing process.

[0087] In the present application, the electrolytic phosphating replenishing powder is put into a tablet press to obtain electrolytic phosphating replenishing tablets. The purpose of this step is to solidify the powder into tablets with certain strength and dispersion performance through the tablet pressing process, facilitating storage, transportation, and use.

[0088] In the third aspect of the present application, the electrolytic phosphating replenishing tablets are applied to the electrolytic phosphating process.

[0089] In some embodiments, the electrolytic phosphating process, during the electrolytic phosphating process, electrolytic phosphating replenishment tablets are added to the electrolyte, and the composition of the electrolyte is monitored.

[0090] In particular, the electrolytic phosphating process includes the following steps:

[0091] S201. Mounting the anode plate in the electrolytic phosphating tank, connecting the positive electrode of the electrolysis power supply, and connecting the conductive pressure roller to the negative electrode of the electrolysis power supply;

[0092] S202. Injecting the electrolytic phosphating solution into the electrolytic phosphating tank, heating, and stirring;

[0093] S203. Connecting the raw material coiled wire to the straightening machine, the abrasive belt machine, the conductive pressure roller, the water washing tank, the electrolytic phosphating tank, the post-water washing tank, the hot air dryer, and the inverted wire collecting machine in sequence;

[0094] S204. Setting the current density and the wire running speed, turning on the electrolytic phosphating power supply and the inverted wire collecting, and performing electrolytic phosphating treatment on the raw material wire.

[0095] S205. During the electrolytic phosphating process, electrolytic phosphating replenishment tablets are regularly and timely supplemented, and the composition change of the electrolyte is monitored.

[0096] More specifically, the electrolytic phosphating process includes the following steps:

[0097] S201. Mounting the anode plate in the electrolytic phosphating tank, connecting the positive electrode of the electrolysis power supply, and connecting the conductive pressure roller to the negative electrode of the electrolysis power supply;

[0098] S202. Injecting the electrolytic phosphating solution into the electrolytic phosphating tank, heating, and stirring, and the heating temperature is 40-60°C, and the stirring speed is maintained at 100-200 r / min;

[0099] S203. Connecting the raw material coiled wire to the straightening machine, the abrasive belt machine, the conductive pressure roller, the water washing tank, the electrolytic phosphating tank, the post-water washing tank, the hot air dryer, and the inverted wire collecting machine in sequence;

[0100] S204. Setting the current density and the wire running speed, turning on the electrolytic phosphating power supply and the inverted wire collecting, and the current density is set to 5-25 A / dm 2 , and the wire running speed is maintained at 0.6-1.6 m / s, and performing electrolytic phosphating treatment on the raw material wire.

[0101] S205. During the electrolytic phosphating process, every 1 m 2 of the surface area of the wire is electrolytic phosphated, 2-3 g of electrolytic phosphating replenishment tablets are supplemented, and the composition change of the electrolyte is monitored.

[0102] In this application, the electrolytic phosphating solution is heated and stirred. The purpose of this step is to promote the mass transfer of the electrolytic phosphating solution and ensure uniform distribution of the film-forming ions.

[0103] In this application, the raw disc round wire is sequentially connected to the straightening machine, the abrasive belt machine, the conductive pressure roller, the water washing tank, the electrolytic phosphating tank, the post-washing tank, the hot air dryer, and the inverted wire collecting machine. The purpose of this step is to ensure the cleanliness of the wire surface through the pretreatment steps (straightening, removing the oxide layer, water washing, etc.), to ensure that the wire surface is free of impurities, to prepare for electrolytic phosphating, and to improve the adhesion and uniformity of the phosphating film.

[0104] In this application, the current density and the wire speed are set, the electrolytic phosphating power is turned on, and the inverted wire collecting is performed. The purpose of this step is to control the parameters of the electrolytic phosphating process, to ensure the formation speed and quality of the phosphating film on the wire surface, and to maintain the production efficiency.

[0105] The electrolytic phosphating replenishing composition and the electrolytic phosphating replenishing tablet of the present application will be further described in conjunction with specific examples and comparative examples:

[0106] In the following examples and comparative examples, the specifications and sources of some raw materials are as follows:

[0107] Polyvinylpyrrolidone, CAS No.: 9003-39-8.

[0108] Polyoxyethylene ether, CAS No.: 9004-95-9.

[0109] Example 1

[0110] The electrolytic phosphating replenishing composition prepared from phosphating waste residue includes the following raw materials in weight percentage:

[0111] Polyvinylpyrrolidone 1%, hydroxypropyl methylcellulose 1%, citric acid 5%, malic acid 2.5%, tartaric acid 1.5%, succinic acid 1%, sodium bicarbonate 30%, polyethylene glycol 4000 4%, polyethylene glycol 6000 2%, polyoxyethylene ether 2%, and the balance is phosphating residue powder;

[0112] The electrolytic phosphating replenishing tablet includes the electrolytic phosphating replenishing composition described above; the preparation process of the electrolytic phosphating replenishing tablet includes the following steps:

[0113] S101. The phosphating residue is added to dilute phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5. The temperature is raised to 60°C, and continuous stirring is performed at a stirring speed of 160 r / min for 2 h to obtain a phosphating residue solid-liquid mixture.

[0114] S102. Multiple times zinc oxide is added to the phosphating residue solid-liquid mixture, 10 grams each time, the pH value of the phosphating residue solid-liquid mixture is adjusted to 7, the temperature is raised, the temperature is kept at 80℃, the stirring is continued for 4h, the stirring speed is 200r / min, hot filtration is carried out, the filtration temperature is kept at 70℃, the phosphating residue wet residue is obtained;

[0115] S103. The phosphating residue wet residue is put into a drying machine for drying, the temperature is 120℃, the drying time is 6h, the rotating speed of the drying machine is controlled at 60r / min, the phosphating residue powder is obtained.

[0116] S104. The raw materials are prepared according to the weight of the corresponding raw materials in the weight percentage, and are respectively stored in a dryer below 60℃ to obtain the dry powder of the raw materials, the moisture content of the raw materials is within 1%;

[0117] S105. The dry binder, organic acid, sodium bicarbonate, lubricating release agent and phosphating residue powder are added to a grinding machine, the grinding fineness is 100 meshes, the mixture is fully ground and uniformly mixed, sieved, the screen mesh aperture is 120 meshes, the electrolytic phosphating replenishing powder is obtained.

[0118] S106. The electrolytic phosphating replenishing powder is put into a tablet press, the tablet is pressed under the pressure of 15MPa, the tablet thickness is 6mm, the electrolytic phosphating replenishing tablet is obtained.

[0119] An electrolytic phosphating process using the electrolytic phosphating replenishing tablet described above, comprising the following steps:

[0120] S201. The anode plate is installed in the electrolytic phosphating tank, connected to the positive electrode of the electrolysis power supply, and the conductive pressure wheel is connected to the negative electrode of the electrolysis power supply.

[0121] S202. The electrolytic phosphating solution is injected into the electrolytic phosphating tank, heated, the heating temperature is 60℃, and stirred, the stirring speed is kept at 200r / min.

[0122] S203. The raw material coil is sequentially connected to the straightening machine, the abrasive belt machine, the conductive pressure wheel, the water washing tank, the electrolytic phosphating tank, the post-water washing tank, the hot air dryer and the inverted wire collecting machine.

[0123] S204. The current density and the wire running speed are set, the electrolytic phosphating power supply and the inverted wire collecting are turned on, the current density is set to 25A / dm 2 , the wire running speed is kept at 1.6m / s, and the raw material wire is subjected to electrolytic phosphating treatment.

[0124] S205. During the electrolytic phosphating process, 3g of electrolytic phosphating replenishing tablet is supplemented for every 1m 2 of the wire with surface area, and the composition change of the electrolyte is monitored.

[0125] Example 2

[0126] The electrolytic phosphating replenishing composition prepared by using phosphating waste residue comprises the following raw materials in percentage by weight:

[0127] Polyvinylpyrrolidone 1%, citric acid 2%, malic acid 2%, tartaric acid 1%, sodium bicarbonate 15%, polyethylene glycol 6000 1%, polyoxyethylene ether 1%, and the rest is phosphating residue powder;

[0128] The electrolytic phosphating replenishing tablet comprises the electrolytic phosphating replenishing composition described above; and a preparation process of the electrolytic phosphating replenishing tablet comprises the following steps:

[0129] S101. The phosphating residue is put into dilute phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5, the temperature is kept at 40℃, and the stirring is continuously carried out at a speed of 100 r / min for 2 h to obtain a phosphating residue solid-liquid mixture.

[0130] S102. Zinc oxide is added into the phosphating residue solid-liquid mixture for multiple times, 5 g each time, the pH value of the phosphating residue solid-liquid mixture is adjusted to 7, the temperature is raised and kept at 60℃, and the stirring is continuously carried out at a speed of 160 r / min for 4 h, and then the phosphating residue wet residue is obtained by filtering while hot at a filtering temperature of 60℃.

[0131] S103. The phosphating residue wet residue is put into a drying machine for drying at a temperature of 120℃ for 6 h, and the rotating speed of the drying machine is controlled at 30 r / min to obtain phosphating residue powder.

[0132] S104. The raw materials are prepared according to the weight of the corresponding raw materials in percentage by weight, and are respectively stored in a drier below 60℃ to obtain raw material dry powder, and the moisture content of the raw materials is within 1%.

[0133] S105. The dry binder, organic acid, sodium bicarbonate, lubricating release agent and phosphating residue powder are added into a grinding machine, and are ground to a fineness of 80 mesh, and are fully ground, mixed and sieved to obtain electrolytic phosphating replenishing powder, and the mesh size of the sieve is 80 mesh.

[0134] S106. The electrolytic phosphating replenishing powder is put into a tablet press, and is pressed into tablets under a pressure of 5 MPa, and the thickness of the tablets is 4 mm to obtain electrolytic phosphating replenishing tablets.

[0135] An electrolytic phosphating process using the electrolytic phosphating replenishing tablet described above comprises the following steps:

[0136] S201. An anode plate is installed in an electrolytic phosphating tank, and is connected to a positive electrode of an electrolysis power supply, and a conductive pressure wheel is connected to a negative electrode of the electrolysis power supply.

[0137] S202. The electrolytic phosphating solution is injected into the electrolytic phosphating tank, heated, the heating temperature is 40℃, stirred, and the stirring speed is maintained at 100 r / min;

[0138] S203. The raw material coil is sequentially connected to the straightening machine, the abrasive belt machine, the conductive pressure roller, the water washing tank, the electrolytic phosphating tank, the post-water washing tank, the hot air dryer, and the inverted wire collecting machine.

[0139] S204. The current density and the wire running speed are set, the electrolytic phosphating power supply and the inverted wire collecting are turned on, the current density is set to 5 A / dm 2 , the wire running speed is maintained at 0.6 m / s, and the raw material wire is subjected to electrolytic phosphating treatment.

[0140] S205. During the electrolytic phosphating process, every 1 m 2 of the surface area of the wire, 2 g of the electrolytic phosphating replenishing tablet is supplemented, and the composition change of the electrolyte is monitored.

[0141] Example 3

[0142] The electrolytic phosphating replenishing composition prepared by using the phosphating waste residue comprises the following raw materials in percentage by weight:

[0143] 0.5% of polyvinylpyrrolidone, 0.5% of hydroxypropyl methylcellulose, 0.5% of sodium carboxymethylcellulose, 2.5% of citric acid, 2.5% of tartaric acid, 2.5% of succinic acid, 22.5% of sodium bicarbonate, 2.5% of polyethylene glycol 4000, 2.5% of polyoxyethylene ether, and the balance of phosphating residue powder;

[0144] The electrolytic phosphating replenishing tablet comprises the electrolytic phosphating replenishing composition described above; and a preparation process of the electrolytic phosphating replenishing tablet comprises the following steps:

[0145] S101. The phosphating residue is put into dilute phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5, the temperature is raised and maintained at 50℃, and stirring is continuously performed at a stirring speed of 130 r / min for 2 h to obtain a phosphating residue solid-liquid mixture.

[0146] S102. Zinc oxide is added to the phosphating residue solid-liquid mixture multiple times, 7.5 g each time, the pH value of the phosphating residue solid-liquid mixture is adjusted to 7, the temperature is raised and maintained at 70℃, and stirring is continuously performed at a stirring speed of 180 r / min for 4 h, and then the phosphating residue wet residue is obtained by hot filtration at a filtration temperature of 65℃.

[0147] S103. The phosphating residue wet residue is put into a drying machine for drying at a temperature of 120℃ for 6 h, and the rotation speed of the drying machine is controlled at 45 r / min to obtain phosphating residue powder.

[0148] S104. The raw materials are prepared according to the weight of the corresponding raw material in weight percentage, and are respectively stored in a dryer below 60°C to obtain dry powder of the raw materials, and the moisture content of the raw materials is within 1%;

[0149] S105. The dry binder, organic acid, sodium bicarbonate, lubricating release agent, and phosphating residue powder are added to a grinding machine, and are ground to a fineness of 90 mesh, mixed uniformly, sieved through a sieve with a mesh size of 100 mesh, to obtain an electrolytic phosphating replenishing powder;

[0150] S106. The electrolytic phosphating replenishing powder is put into a tablet press, and tablets are pressed under a pressure of 10 MPa, and the thickness of the tablets is 5 mm, to obtain electrolytic phosphating replenishing tablets.

[0151] An electrolytic phosphating process using the electrolytic phosphating replenishing tablets described above, comprising the following steps:

[0152] S201. The anode plate is installed in the electrolytic phosphating tank and connected to the positive electrode of the electrolysis power supply, and the conductive pressure wheel is connected to the negative electrode of the electrolysis power supply;

[0153] S202. The electrolytic phosphating solution is injected into the electrolytic phosphating tank, heated to a temperature of 50°C, and stirred at a speed of 150 r / min;

[0154] S203. The raw material coil is sequentially connected to the straightening machine, the abrasive belt machine, the conductive pressure wheel, the water washing tank, the electrolytic phosphating tank, the post-water washing tank, the hot air dryer, and the inverted wire collecting machine;

[0155] S204. The current density and wire speed are set, the electrolytic phosphating power supply and the inverted wire collecting are turned on, the current density is set to 15 A / dm 2 , and the wire speed is kept at 1.1 m / s, and the raw wire is subjected to electrolytic phosphating treatment.

[0156] S205. During the electrolytic phosphating process, 2.5 g of electrolytic phosphating replenishing tablets are supplemented for every 1 m 2 of surface area of the wire, and the composition change of the electrolyte is monitored.

[0157] Example 4

[0158] The electrolytic phosphating replenishing composition prepared from phosphating waste residue includes the following raw materials in weight percentage:

[0159] Polyvinylpyrrolidone 1%, hydroxypropyl methylcellulose 1%, citric acid 5%, malic acid 2.5%, tartaric acid 1.5%, succinic acid 1%, sodium bicarbonate 30%, polyethylene glycol 4000 4%, polyethylene glycol 6000 2%, polyoxyethylene ether 2%, and the balance is phosphating residue powder;

[0160] An electrolytic phosphating replenishment tablet comprising the electrolytic phosphating replenishment composition described above; a preparation process of the electrolytic phosphating replenishment tablet comprising the following steps:

[0161] S101. The phosphating residue is put into dilute phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5, the temperature is kept at 40°C, and stirring is continued for 2h at a stirring speed of 100r / min, to obtain a phosphating residue solid-liquid mixture.

[0162] S102. Zinc oxide is added to the phosphating residue solid-liquid mixture multiple times, 5g each time, the pH value of the phosphating residue solid-liquid mixture is adjusted to 7, the temperature is raised and kept at 60°C, and stirring is continued for 4h at a stirring speed of 160r / min, and then the phosphating residue wet residue is obtained by filtering while hot at a filtering temperature of 60°C.

[0163] S103. The phosphating residue wet residue is put into a drying machine for drying at a temperature of 120°C for 6h, and the rotation speed of the drying machine is controlled at 30r / min, to obtain phosphating residue powder.

[0164] S104. The raw materials are prepared according to the weight of the corresponding raw materials in the weight percentage, and are respectively stored in a dryer below 60°C to obtain raw material dry powder, and the water content of the raw materials is within 1%.

[0165] S105. The dry binder, organic acid, sodium bicarbonate, lubricating release agent, and phosphating residue powder are added to a grinding machine, and are ground to a fineness of 80 meshes, and are fully ground and mixed uniformly, and are sieved through a sieve with a mesh size of 80 meshes, to obtain electrolytic phosphating replenishment powder.

[0166] S106. The electrolytic phosphating replenishment powder is put into a tablet press, and is pressed into tablets under a pressure of 5MPa, and the thickness of the tablets is 4mm, to obtain electrolytic phosphating replenishment tablets.

[0167] An electrolytic phosphating process using the electrolytic phosphating replenishment tablets described above, comprising the following steps:

[0168] S201. An anode plate is installed in an electrolytic phosphating tank, and is connected to the positive pole of an electrolysis power supply, and a conductive pressure wheel is connected to the negative pole of the electrolysis power supply.

[0169] S202. The electrolytic phosphating liquid is injected into the electrolytic phosphating tank, and is heated to a temperature of 40°C, and is stirred at a stirring speed of 100r / min.

[0170] S203. The raw material disc-shaped wire is sequentially connected to a straightening machine, a sand belt machine, a conductive pressure wheel, a water washing tank, an electrolytic phosphating tank, a post-water washing tank, a hot air drying machine, and an inverted wire collecting machine.

[0171] S204. The current density and the wire running speed are set, the electrolytic phosphating power supply and the inverted wire collecting are turned on, the current density is set to 5A / dm2 The wire speed is kept at 0.6 m / s, and the raw wire is subjected to electrolytic phosphating treatment.

[0172] S205. In the electrolytic phosphating process, 1 m 2 The surface area wire is supplemented with 2 g of electrolytic phosphating replenishing tablets, and the composition change of the electrolyte is monitored.

[0173] Example 5

[0174] The electrolytic phosphating replenishing composition prepared by using phosphating waste residue includes the following raw materials in percentage by weight:

[0175] Polyvinylpyrrolidone 1%, citric acid 2%, malic acid 2%, tartaric acid 1%, sodium bicarbonate 15%, polyethylene glycol 6000 1%, polyoxyethylene ether 1%, and the rest is phosphating residue powder;

[0176] The electrolytic phosphating replenishing tablet includes the electrolytic phosphating replenishing composition described above; and a preparation process of the electrolytic phosphating replenishing tablet includes the following steps:

[0177] S101. The phosphating residue is put into dilute phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5, the temperature is kept at 60°C, and the stirring is continuously performed at a speed of 160 r / min for 2 h to obtain a phosphating residue solid-liquid mixture.

[0178] S102. Zinc oxide is added to the phosphating residue solid-liquid mixture multiple times, 10 g each time, the pH value of the phosphating residue solid-liquid mixture is adjusted to 7, the temperature is increased and kept at 80°C, the stirring is continuously performed at a speed of 200 r / min for 4 h, and the wet residue is obtained by filtering while hot at a filtering temperature of 70°C.

[0179] S103. The phosphating residue wet residue is put into a drying machine for drying at a temperature of 120°C for 6 h, and the rotation speed of the drying machine is controlled at 60 r / min to obtain phosphating residue powder.

[0180] S104. The raw materials are prepared according to the weight of the corresponding raw materials in percentage by weight, and are respectively stored in a dryer below 60°C to obtain dry raw powder, and the water content of the raw materials is within 1%.

[0181] S105. The dry binder, organic acid, sodium bicarbonate, lubricating release agent, and phosphating residue powder are added to a grinding machine, and are ground to a fineness of 100 meshes, are fully ground and mixed uniformly, are sieved through a sieve with a mesh size of 120 meshes to obtain electrolytic phosphating replenishing powder.

[0182] S106. The electrolytic phosphating replenishing powder is put into a tablet press, and is pressed into tablets under a pressure of 15 MPa, and the thickness of the tablets is 6 mm to obtain electrolytic phosphating replenishing tablets.

[0183] An electrolytic phosphating process using the above-mentioned electrolytic phosphating replenishing tablet, comprising the following steps:

[0184] S201. Mounting the anode plate in the electrolytic phosphating tank, connecting the positive electrode of the electrolytic power supply, and connecting the conductive pressure roller with the negative electrode of the electrolytic power supply;

[0185] S202. Injecting the electrolytic phosphating solution into the electrolytic phosphating tank, heating, heating temperature is 60℃, stirring, stirring speed is kept at 200r / min;

[0186] S203. Connecting the raw material coil in sequence to the straightening machine, the abrasive belt machine, the conductive pressure roller, the water washing tank, the electrolytic phosphating tank, the post-washing tank, the hot air dryer, and the inverted take-up machine;

[0187] S204. Setting the current density and the wire speed, turning on the electrolytic phosphating power supply and the inverted take-up, setting the current density to 25A / dm 2 , and keeping the wire speed at 1.6m / s, and performing electrolytic phosphating treatment on the raw material wire.

[0188] S205. During the electrolytic phosphating process, supplementing 3g of the electrolytic phosphating replenishing tablet for every 1m 2 of the wire with a surface area, and monitoring the composition change of the electrolyte.

[0189] Comparative Example 1

[0190] No sodium bicarbonate is added in the raw material of the electrolytic phosphating replenishing tablet, and the rest of the conditions are consistent with Example 3.

[0191] Comparative Example 2

[0192] No organic acid is added in the raw material of the electrolytic phosphating replenishing tablet, and the rest of the conditions are consistent with Example 3.

[0193] Comparative Example 3

[0194] No binder is added in the raw material of the electrolytic phosphating replenishing tablet, and the rest of the conditions are consistent with Example 3.

[0195] Comparative Example 4

[0196] No step S105 of grinding and sieving is performed during the preparation of the electrolytic phosphating replenishing tablet, and the rest of the conditions are consistent with Example 3.

[0197] Comparative Example 5

[0198] During the preparation of the electrolytic phosphating replenishing tablet, the tabletting pressure in step S106 is set to 50MPa, and the tablet thickness is 2mm, and the rest of the conditions are consistent with Example 3.

[0199] Comparative Example 6

[0200] Electrolytic phosphating using the process (electrolytic phosphating process of the electrolytic phosphating replenishing tablets described above), step S205 every electrolytic phosphating 1 m 2 Surface area wire, supplement 0.03 g electrolytic phosphating replenishing tablets, the rest of the conditions and example 3 are consistent.

[0201] The technical index of the electrolytic phosphating replenishing tablets prepared in the above examples and comparative examples, and the phosphating film of the wire rod after electrolytic phosphating are detected, and the results are as follows:

[0202] 1. The electrolytic phosphating replenishing tablets prepared in examples 1-5 and comparative examples 1-6 are tested for dispersibility:

[0203] 100 g of the electrolytic phosphating replenishing tablets prepared in the above examples and comparative examples are respectively dissolved in 1 kg of YX-702# type electrolytic phosphating tank liquid with free acidity of 16 pt and temperature of 45 ℃, and after standing for 1 h, the state of the electrolytic phosphating tank liquid is observed, filtered to obtain filter residue, and dried.

[0204] The dispersibility is expressed by the percentage of the part of the tablet dissolved in the tank liquid in the total weight of the tablet, that is, by

(total weight of electrolytic phosphating replenishing tablets-filter residue weight) / total weight of electrolytic phosphating replenishing tablets × 100%

[0205] Table 1

[0206] Sample State of appearance of the bath Dispersibility (%) Example 1 Clear 98.4 Example 2 Clear 96.9 Example 3 Clear 97.3 Example 4 Clear 99.2 Example 5 Clear 96.2 Comparative Example 1 Large amount of precipitate at the bottom of the bath 22.5 Comparative Example 2 Precipitate at the bottom of the bath and agglomerates floating in the bath 73.4 Comparative Example 3 Slightly turbid 86.5 Comparative Example 4 Slightly turbid 87.1 Comparative Example 5 Precipitate at the bottom of the bath and agglomerates floating in the bath 72.4

[0207] As shown in the results in Table 1, the dispersibility of the electrolytic phosphating replenishing tablets in the tank liquid in the comparative examples is significantly lower than that of the samples in the examples.

[0208] In comparative example 1, since sodium bicarbonate is not added, the electrolytic phosphating replenishing tablets cannot be effectively disintegrated in the electrolytic phosphating tank liquid. As a disintegrating agent, sodium bicarbonate reacts with organic acid and free acid in the electrolytic phosphating tank liquid to generate carbon dioxide gas, which is the key to the rapid disintegration of the tablets. Without sodium bicarbonate, the tablets cannot be rapidly disintegrated, resulting in a large amount of precipitation at the bottom of the tank liquid, and the effective components in the tablets cannot be effectively released, so the dispersibility is significantly lower than that of the examples.

[0209] In comparative example 2, since no organic acid is added, sodium bicarbonate can only react with free acid in the electrolytic phosphating tank liquid, so it can only gradually disintegrate the tablets from the outside. This disintegration process from the outside to the inside is not as good as the simultaneous disintegration from the inside and outside, so the dispersibility is poor. This affects the stability and dispersibility of the tablets in the tank liquid, resulting in precipitation at the bottom of the tank liquid, agglomerates floating in the tank liquid, and although the tablets are partially dissolved, the overall dispersibility is not good.

[0210] In Comparative Example 3, the lack of binder resulted in the phosphating waste powder not being able to bind effectively. Although this did not directly affect the disintegration of the tablets, it did affect the tablet formability. The tablets may partially disintegrate in the electrolytic phosphating bath, causing slight turbidity, which was worse than the example with added binder.

[0211] In Comparative Example 4, the omission of the grinding and sieving steps resulted in uneven particle size and inconsistent component distribution of the electrolytic phosphating feed powder, which caused the tablets to dissolve unevenly in the bath solution, resulting in slight turbidity. This indicates that although most tablets could dissolve, the dispersibility was still not ideal due to the uneven particle size.

[0212] In Comparative Example 5, excessive tableting pressure and excessively thin tablets resulted in an overly dense tablet structure, which made it difficult for the tablets to disintegrate in the electrolytic phosphating bath, resulting in sediment at the bottom of the bath and agglomerates floating in the bath, indicating that the tablets failed to disintegrate and disperse effectively.

[0213] 2. Perform electrolytic phosphating operations according to the requirements of each embodiment and comparative example, and continue electrolytic phosphating for 3 minutes. 2 After applying Q235 substrate to the surface area, the technical indicators of the phosphating film layers in Examples 1-5 and Comparative Examples 1-6 were tested, and the test results are shown in Table 2.

[0214] The specific testing methods or conditions are as follows:

[0215] ① Adhesion, according to GB / T 1720-2020 paint film circumference test

[0216] ② Corrosion resistance: Copper sulfate pitting test. The pitting solution is dropped onto the sample, and the time it takes for red corrosion spots to appear is observed. The pitting solution is: 41g copper sulfate pentahydrate, 35g sodium chloride, 13mL 0.1mol / L hydrochloric acid, diluted to 1L with distilled water.

[0217] ③ Soak in sodium chloride solution: Immerse the phosphating sample (at room temperature) in a 3% sodium chloride aqueous solution and keep it at room temperature for the specified time. Visually inspect the phosphating surface for rust.

[0218] ④ For indoor rust prevention, after drying, store the test pieces at room temperature with relative humidity not exceeding 70% and free from corrosive gases, and record the storage time.

[0219] Table 2

[0220]

[0221]

[0222] According to Table 2, we can see that the phosphating film obtained by the examples performs excellently in thickness, adhesion, corrosion resistance, resistance to sodium chloride solution immersion, and indoor rust prevention, and the film layer is crystalline, dense, and continuous and uniform. This shows that the electrolytic phosphating replenishing tablet prepared from phosphating waste residue can effectively maintain the stability of the concentration of film-forming ions in the electrolytic phosphating bath, thereby realizing the uniformity and density of the electrolytic phosphating film layer and improving the quality of the electrolytic phosphating film layer.

[0223] In contrast, the phosphating film obtained by the comparative examples is inferior to the film obtained by the examples in various indicators, which shows that factors such as not adding sodium bicarbonate, organic acid, binder, or the grinding and sieving step, excessive tabletting pressure, and insufficient replenishment will affect the quality and application effect of the electrolytic phosphating film layer.

[0224] 3. Perform electrolytic phosphating according to the requirements of each example and comparative example, and after 3m 2 The effects of the phosphating film layers obtained by Example 3, Comparative Example 1, and Comparative Example 6 on the Q235 substrate were observed by metallographic microscope;

[0225] Figure 1 The metallographic microscope photo of the phosphating film obtained by Example 3 shows that the electrolytic phosphating film layer exhibits excellent uniformity and integrity. The film layer surface is smooth, without obvious pores or defects, indicating that the electrolytic phosphating replenishing tablet can uniformly supplement the effective components in the electrolyte, promoting the formation of a dense and uniform phosphating film. The film layer tightly covers the surface of the wire, showing excellent protective performance, which can effectively resist the erosion of the external environment and ensure the durability and protection of the Q235 substrate.

[0226] Figure 2 The metallographic microscope photo of the phosphating film obtained by Comparative Example 1 shows that the film layer quality is poor. Due to the absence of sodium bicarbonate, the disintegration rate of the electrolytic phosphating replenishing tablet is too slow, and the effective components are not fully released. The incompletely disintegrated replenishing tablet is adsorbed on the surface of the substrate to form deposits, and the substrate surface is covered with deposits, hindering the growth of the phosphating film layer and forming uneven hole regions. These uneven regions may become the starting point of corrosion, reducing the overall corrosion resistance. In addition, the integrity of the film layer is insufficient, and some areas may be exposed to corrosion risk due to insufficient protection.

[0227] Figure 3 The metallographic microscope photo of the phosphating film obtained by Comparative Example 6 shows that the phosphating film layer has obvious defects. Due to the insufficient replenishment of the electrolytic phosphating replenishing tablet, the concentration of effective components in the electrolyte is insufficient, and a continuous and uniform phosphating film layer cannot be formed, which directly affects the protective performance of the film layer and increases the possibility of corrosion of the substrate.

[0228] The above embodiments are the preferred implementation of the present application, in addition to this, the present application can be implemented in other ways, any obvious replacement without departing from the concept of the present application is within the protection scope of the present application.

Claims

1. An electrolytic phosphating replenishing tablet prepared using phosphating waste residue, characterized in that, The electrolytic phosphating replenishing tablet comprises an electrolytic phosphating replenishing composition, which comprises the following components in weight percentage: 1-2% binder 5-10% organic acid 15-30% sodium bicarbonate 2-8% lubricating release agent the balance being phosphating residue; the binder is any one or any combination of polyvinylpyrrolidone, hydroxypropyl methylcellulose, sodium carboxymethylcellulose; the organic acid is any one or any combination of citric acid, malic acid, tartaric acid and succinic acid; the lubricating release agent is any one or any combination of polyethylene glycol 4000, polyethylene glycol 6000 and polyoxyethylene ether; the phosphating residue is from an immersion phosphating process.

2. The process for the preparation of electrolytic phosphating replenishing tablets according to claim 1, characterized in that, The method comprises the following steps: 1) pretreating the phosphating residue; 2) mixing the pretreated phosphating residue with the binder, the organic acid, the sodium bicarbonate and the lubricating release agent to obtain an electrolytic phosphating replenishing composition; 3) compressing the electrolytic phosphating replenishing composition to obtain an electrolytic phosphating replenishing tablet; in step 1), the pretreatment process is as follows: the phosphating residue is put into phosphoric acid with a concentration of 5% at a mass ratio of 1:0.5 to obtain a phosphating residue solid-liquid mixture; zinc oxide is added to the phosphating residue solid-liquid mixture to adjust the pH value of the phosphating residue solid-liquid mixture to 7, and then the mixture is filtered to obtain a phosphating residue wet residue; the phosphating residue wet residue is dried to obtain a phosphating residue powder.

3. The preparation method according to claim 2, characterized in that, in step 3), the compression pressure is controlled at 5-15 MPa, and the thickness of the electrolytic phosphating replenishing tablet is 4-6 mm.

4. Use of an electrolytic phosphating replenishment tablet, characterized in that The electrolytic phosphating replenishing tablet prepared by the preparation method of any one of claims 2-3 or the electrolytic phosphating replenishing tablet of claim 1 is applied to an electrolytic phosphating process.

5. Use according to claim 4, characterized in that, In the electrolytic phosphating process, the electrolytic phosphating replenishing tablet is added to the electrolyte, and the composition of the electrolyte is monitored.

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