Steel plate enamel high temperature titanium milk yellow face glaze without fluorinated salt and nitrate and its preparation method and application

Abstract

The application discloses a steel plate enamel high-temperature titanium milk yellow face glaze free of fluorinated salt and nitrate, a preparation method and application thereof, and belongs to the technical field of enamel. The face glaze is prepared from quartz, zero-water borax, rutile, potassium feldspar, trisodium phosphate, potassium carbonate, potassium dichromate and zinc oxide according to specific mass proportions. The preparation comprises raw material mixing, smelting at 1300+ / -10 DEG C under a pure oxygen environment, and rapid cooling after wire drawing detection of the smelting state. The face glaze completely avoids the use of fluorinated salt and nitrate, eliminates fluorine emission and environmental protection equipment blockage problems from the source, the fluorine content of the product is not detected through detection, meets the limit value requirements of the EU REACH regulation, has good color, gloss and firing adaptability, is suitable for a steel plate substrate, has a firing temperature of 840-880 DEG C, and can be used for the production of green and environmentally-friendly enamel products.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of enamel, and particularly relates to a steel plate enamel high-temperature titanium milk yellow face glaze without fluorinated salt and nitrate, and a preparation method and application thereof. BACKGROUND

[0002] The steel plate enamel high-temperature titanium milk yellow face glaze needs to meet three core indexes of high opacity (milk performance), hue and gloss. The traditional formula relies on fluorinated salt (fluorite / fluorosilicate accounts for 1-12%) to achieve fluxing. The fluorinated salt in the traditional high-temperature titanium milk yellow face glaze is not an "optional" additive, but an "indispensable" skeleton component. Since the fluorinated salt has multiple synergies of reducing the melting temperature, forming an alloy layer by corroding the interface, creating a mechanical anchoring effect, improving the opacity and wettability, simply and roughly removing the fluorinated salt is equivalent to removing the load-bearing wall of the building, which does not lead to "performance decline", but "collapse" of the entire enamel system. Any fluorine-free attempt must be based on finding or inventing a new substance or new process system that can completely simulate or replace the above multiple functions, and this is still a major technical challenge in the enamel process field. Therefore, the importance of fluorinated salt in the traditional process cannot be overemphasized. However, research has shown that:

[0003] 1. Hydrogen fluoride (HF) and silicon tetrafluoride (SiF4) gases released during high-temperature melting process cause damage to health and environment.

[0004] 2. The European Union REACH regulation lists fluorides as a high-concern substance (SVHC), and fluorinated salt products cannot meet the EU REACH regulation requirements for fluorine, with a fluorine (F) limit of 20 mg / kg.

[0005] 3. End environmental management equipment is blocked due to fluorinated salt crystallization, which seriously restricts normal production of enterprises.

[0006] At the same time, nitrate as a traditional oxidizing agent and adhesion promoting component, is prone to produce nitrogen oxides (NO x ) during high-temperature decomposition, also facing environmental pressure. Currently, the denitration of enamel glaze has solved the problem of nitrogen oxide emission (such as CN114368912B, CN114315150B, CN114315151B, etc.), and further realizing fluorine-free, promoting the research and development of fluorine-free and nitrate-free system is not only a necessary choice to respond to regulations, but also a forward-looking technical layout for the future.

[0007] The replacement of fluorinated salt is a major technical bottleneck at present, mainly reflected in:

[0008] (1) Fluorinated salt dependence is strong, and environmental risk is prominent: CN119710693A (high-temperature-resistant enamel glaze) uses cryolite (Na3AlF6) as a fluxing agent, although it improves temperature resistance, but does not solve the problem of fluorine emission; CN112342544A (low-temperature acid and alkali-resistant cast iron enamel) contains sodium fluoride (5-7 parts) in the face glaze formula.

[0009] (2) Non-fluorine substitution scheme has functional defects: CN105800935A (enamel underglaze material) attempts to use lanthanide oxides to enhance adhesion, but it still needs to add 8% fluorine to assist melting, and the high cost of rare earth makes it difficult to promote. CN116854374A (black enamel composite glaze) uses a cobalt-nickel underglaze system, but the anti-explosive agent used contains 8-10% fluorite powder.

[0010] (3) The field of ceramics involves fluorine-free schemes, but it is difficult to apply: CN110885189A relates to a zirconium-free lanolin enamel and a positioning crystal flower ceramic tile made using the same, CN115626774A relates to a soft light skin ceramic rock plate and a method for preparing the same, CN112979271A relates to a method for preparing a light-weight high-strength pure-color glaze tile, and CN118754723A relates to a hydrophilic self-cleaning antique tile based on phase separation and a method for preparing the same. Although the above-mentioned prior art does not involve the use of fluorinated salt, its technical essence belongs to the field of building ceramic glaze, which is different from the field of enamel underglaze. There are essential differences between ceramic glaze and metal-based enamel glaze in terms of thermal expansion coefficient (the difference in expansion coefficient between the two is one order of magnitude), firing temperature (the firing temperature of ceramic glaze is higher than that of enamel glaze by more than 200°C), and bonding mechanism (the body of ceramic glaze is porcelain clay, while the body of enamel glaze is metal), thus it cannot be directly applied to the field of metal-based enamel.

[0011] In summary, on the basis of denitrification, the problem of defluorination is solved, and the quality of enamel products is improved, which has very important practical significance for promoting the green, low-carbon, and high-quality development of the enamel industry. SUMMARY

[0012] In view of the excessive emission of fluorides in the production process of existing enamel glaze, which causes damage to health and the environment, the fluorinated salt-containing products cannot meet the requirements of the EU REACH regulation on fluorine, and the emitted fluorinated salt blocks environmental management facilities, which seriously restricts the normal production of enterprises, a steel plate enamel high-temperature titanium milk yellow face glaze without fluorinated salt and nitrate salt, as well as a preparation method and application thereof are provided.

[0013] The enamel high-temperature titanium milk yellow face glaze of the steel plate without fluorinated salt and nitrate of the application is prepared from the following components in the following mass parts: quartz 36-39 parts, zero-water borax 20-23 parts, rutile 15-18 parts, potassium feldspar 20-23 parts, trisodium phosphate 8-10 parts, potassium carbonate 4.5-7.5 parts, potassium dichromate 0.02-0.05 parts, and zinc oxide 2-3 parts.

[0014] Further, the quartz is 38-39 parts, the zero-water borax is 22-23 parts, the rutile is 17-18 parts, the potassium feldspar is 20-21 parts, the trisodium phosphate is 9-10 parts, the potassium carbonate is 6-7.5 parts, the potassium dichromate is 0.04-0.05 parts, and the zinc oxide is 2.5-3 parts.

[0015] Further, in the quartz, the mass ratio of SiO2 and Fe2O3 is: SiO2≥99%, Fe2O3≤0.05%; in the rutile, the mass ratio of TiO2 is: TiO2≥99%; and the zinc oxide is prepared by distillation of metallic zinc and then oxidation, and the mass purity is ≥99.7%.

[0016] The preparation method of the enamel high-temperature titanium milk yellow face glaze of the steel plate without fluorinated salt and nitrate, comprising the following steps:

[0017] (1) the raw materials are weighed according to the above mass parts;

[0018] (2) the raw materials in step (1) are stirred and mixed uniformly;

[0019] (3) the uniformly mixed material is added into a melting furnace, and melting is carried out under pure oxygen condition, and the melting temperature is controlled at 1300±10℃;

[0020] (4) after the material in step (3) is completely melted, a borosilicate glass body is obtained, the molten borosilicate glass body is struck, and is quickly drawn into a glass filament of 1.2-1.5 meters for detection, and the detection requirement is: no knot is found in 1 meter of the glass filament, and the melting is continued for 5-10 minutes, and then the melting is completed;

[0021] (5) the molten borosilicate glass body is rapidly cooled, and the product is obtained.

[0022] Further, in step (5), the rapid cooling is carried out by water quenching or tabletting process.

[0023] The enamel high-temperature titanium milk yellow face glaze of the steel plate without fluorinated salt and nitrate is applied to a blank with a steel plate as a base body, and the firing temperature of the finished product is 840-880℃, and does not include the end point value 840℃.

[0024] In addition, by adjusting the components and amount of the fluxing agent of the non-fluorinated salt in the formula of the present application, the melting of the enamel can be completed as required even without the fluxing of the fluorinated salt; the zinc oxide is introduced into the formula of the high-temperature titanium milk yellow enamel of the steel plate enamel, which cooperates with the titanium dioxide in the rutile, the ZnO / TiO2 reduces the viscosity of the liquid phase, and accelerates the diffusion of ions and bubbles; the amount of the phosphate is increased, on the one hand, the phosphate provides the [PO4] 3- group to promote the nucleation of feldspar, and on the other hand, the eutectic complex fluxing system of the "carbonate + phosphate + borate" is formed to strengthen the fluxing, and the components cooperate to promote the improvement of the gloss, opacity, sintering performance and other performances of the enamel.

[0025] The present application has the following beneficial effects:

[0026] (1) The fluorinated substance is discharged in an ultra-low standard.

[0027] (2) The product is detected by SGS, and the detection result of the fluorinated substance shows that it is not detected, which meets the limit requirement of the SVHC (high concern substance) of the EU REACH regulation.

[0028] (3) The problem of the blockage of the end environmental protection equipment is solved: by completely removing the fluorinated substance (fluorite, sodium fluorosilicate, etc.), the fluorinated salt crystallization source is eliminated from the source, and the problem of the blockage of the end environmental protection equipment is solved. According to the actual measurement of the production line, the continuous operation period of the equipment is prolonged from the original 10-15 days to more than 180 days, and the maintenance cost is significantly reduced.

[0029] (4) The sintering adaptability is good: the eutectic complex fluxing system (carbonate + phosphate + borate) interacts with other components, so that the sintering temperature is stably controlled at 840-880℃, and the enamel surface has good leveling property.

[0030] (5) The amount of the phosphate is increased, the phosphate provides the [PO4] 3- group to promote the nucleation of feldspar; the amount of the zinc oxide is increased, the ZnO / TiO2 reduces the viscosity of the liquid phase, accelerates the diffusion of ions, and cooperates with other components to enhance the opacity (opalescence performance) and gloss of the enamel. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The photo of the enamel plate made of the product obtained in Example 1 of the present application. DETAILED DESCRIPTION

[0032] The present application will be further described in detail below in combination with specific examples, but the present application is not limited thereto.

[0033] The equipment used in the examples of the present application is as follows:

[0034] Ingredients: The full-automatic ingredient mixing system is adopted. The system is fully automatic computer control, and has the characteristics of accurate weighing, uniform mixing and high ingredient efficiency.

[0035] Melting: The automatic feeding system, automatic pure oxygen combustion control system and automatic discharging system are adopted.

[0036] Packaging: The automatic packaging system is adopted.

[0037] The purity of the raw materials used in the embodiment of the application meets the requirements of the industrial grade.

[0038] Example 1:

[0039] (1) The raw materials are weighed according to the mass parts of each component as follows:

[0040] Quartz 36 parts, zero-water borax 20 parts, rutile 15 parts, potassium feldspar 20 parts, trisodium phosphate 8 parts, potassium carbonate 4.5 parts, potassium dichromate 0.02 parts, and zinc oxide 2 parts.

[0041] In the quartz, the mass ratio of SiO2 and Fe2O3 is: SiO2≥99%, Fe2O3≤0.05%; in the rutile, the mass ratio of TiO2 is: TiO2≥99%; the zinc oxide is prepared by distillation of metallic zinc and oxidation, and the mass purity is ≥99.7%.

[0042] (2) The above raw materials are stirred and mixed uniformly.

[0043] (3) The uniformly mixed material is added to a melting furnace, and melting is carried out under pure oxygen conditions, with the melting temperature controlled at 1300±10℃.

[0044] (4) After the above material is completely melted, a borosilicate glass body is obtained, the molten borosilicate glass body is tapped, and is quickly drawn into a glass filament of 1.2-1.5 meters for detection. The detection requirement is: within 1 meter of the glass filament, no knot is detected, and the melting is continued for 5 minutes, which is the completion of melting.

[0045] (5) The molten borosilicate glass body is water quenched, and the product is obtained.

[0046] The product prepared by the application is applied to a blank with a steel plate as a base body, and the firing temperature of the finished product is 840-880℃.

[0047] The product obtained in Example 1 of the application is applied to a porcelain enamel plate made of steel plate, as shown in Figure 1 The enamel high-temperature titanium milk yellow face enamel of the steel plate without fluorinated salt and nitrate is flat and delicate, has no obvious defects in appearance, has excellent luster, stable high-temperature color, and the product quality meets the requirements of enterprise standards.

[0048] Example 2:

[0049] The rest is the same as example 1, except that:

[0050] The mass parts of each component in step (1) are: quartz 39 parts, zero-water borax 23 parts, rutile 18 parts, potassium feldspar 23 parts, trisodium phosphate 10 parts, potassium carbonate 7.5 parts, potassium dichromate 0.05 parts, zinc oxide 2.5 parts.

[0051] In step (5), the borosilicate glass body prepared by melting is rapidly cooled by a tabletting process.

[0052] Example 3:

[0053] The rest is the same as example 1, except that:

[0054] The mass parts of each component in step (1) are: quartz 37 parts, zero-water borax 21.45 parts, rutile 16 parts, potassium feldspar 21 parts, trisodium phosphate 8.5 parts, potassium carbonate 5.5 parts, potassium dichromate 0.03 parts, zinc oxide 2.7 parts.

[0055] Example 4:

[0056] The rest is the same as example 1, except that:

[0057] The mass parts of each component in step (1) are: quartz 38 parts, zero-water borax 22 parts, rutile 17 parts, potassium feldspar 21 parts, trisodium phosphate 9 parts, potassium carbonate 6 parts, potassium dichromate 0.04 parts, zinc oxide 3 parts.

[0058] Comparative Example 1

[0059] The rest is the same as example 1, except that: the mass parts of each component in step (1) are: quartz 38 parts, zero-water borax 16 parts, rutile 13 parts, potassium feldspar 22 parts, trisodium phosphate 5 parts, sodium fluorosilicate 8 parts, potassium dichromate 0.04 parts.

[0060] The test results of the products obtained in the above examples and comparative examples are shown in Table 1 below.

[0061] Table 1 Test results of products obtained in each example and comparative example

[0062]

[0063] The above examples and detection results prove that the enamel high-temperature titanium milk yellow face glaze of the steel plate produced by the method of the application does not contain fluorinated salt and nitrate, no fluorinated salt is generated in the preparation process, and after defluorination, the properties (porcelain surface, color, opacity, sintering temperature) of the obtained product meet the requirements of the enamel high-temperature titanium milk yellow face glaze of the steel plate, the fluorinated salt detection result of the product shows that no fluorinated salt is detected, the limit requirement of the European Union REACH regulation on SVHC (substance of very high concern) is met, and the technical problems of the existing enamel high-temperature titanium milk yellow face glaze of the steel plate in the production process, such as the generation of fluorinated gas emission to pollute the environment and the fluorinated salt emission to block the environmental protection treatment facilities, are fundamentally solved.

Claims

1. Steel plate enamel high temperature titanium milk yellow face glaze free of fluorinated salts and nitrates, characterized in that, The formula is composed of the following components in mass parts: quartz 36-39 parts, zero-water borax 20-23 parts, rutile 15-18 parts, potassium feldspar 20-23 parts, trisodium phosphate 8-10 parts, potassium carbonate 4.5-7.5 parts, potassium dichromate 0.02-0.05 parts, and zinc oxide 2-3 parts.

2. The steel plate enamel high temperature titanium milk yellow face glaze without fluorinated salt and nitrate according to claim 1, characterized in that, Quartz 38-39 parts, zero-water borax 22-23 parts, rutile 17-18 parts, potassium feldspar 20-21 parts, trisodium phosphate 9-10 parts, potassium carbonate 6-7.5 parts, potassium dichromate 0.04-0.05 parts, and zinc oxide 2.5-3 parts.

3. The steel plate enamel high temperature titanium milk yellow face glaze without fluorinated salt and nitrate according to claim 1 or 2, characterized in that, In the quartz, the mass ratio of SiO2 and Fe2O3 is: SiO2≥99%, Fe2O3≤0.05%.

4. The steel plate enamel high temperature titanium milk yellow finish without fluorinated salt and without nitrate according to claim 1 or 2, characterized in that, In the quartz, the mass ratio of Fe2O3 is: Fe2O3≤0.05%.

5. The steel plate enamel high temperature titanium milk yellow face glaze without fluorinated salt and nitrate according to claim 1 or 2, characterized in that, In the rutile, the mass ratio of TiO2 is: TiO2≥99%.

6. The steel plate enamel high temperature titanium milk yellow finish without fluorinated salt and without nitrate of claim 1 or 2, characterized in that, The zinc oxide is prepared by distillation of metallic zinc followed by oxidation, and the mass purity is ≥99.7%.

7. The method of producing a steel plate enamel high temperature titanium milk yellow finish free of fluorinated salts and nitrates according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: (1) weighing each component raw material; (2) stirring and mixing the raw materials in step (1) uniformly; (3) adding the uniformly mixed material into a melting furnace, and melting under pure oxygen condition, with the melting temperature controlled at 1300±10℃; (4) after the material in step (3) is completely melted, a borosilicate glass body is obtained, the molten borosilicate glass body is tapped, and is quickly drawn into a 1.2-1.5 meter glass filament for detection, with the detection requirement being that no node is present within 1 meter of the glass filament, and the melting is continued for 5-10 minutes to complete the melting; (5) rapidly cooling the melted borosilicate glass body, and the product is obtained.

8. The production method according to claim 7, wherein In step (5), the rapid cooling is achieved by water quenching or tablet pressing process.

9. Use of a steel plate enamel high temperature titanium milk yellow finish free of fluorinated salts and nitrates according to any one of claims 1 to 6, characterized in that, When applied to a blank with a steel plate as a base body, the firing temperature of the finished product is 840-880℃, and the end point value 840℃ is not included.

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