Steel plate enamel titanium lake blue face glaze without fluorinated salt and nitrate and its preparation method and application

Abstract

The application discloses a steel plate enamel titanium lake blue face glaze free of fluorinated salt and nitrate, a preparation method and application thereof, and belongs to the technical field of enamel. The titanium lake blue face glaze is composed of quartz, zero-water borax, titanium dioxide, soda ash, magnesium carbonate, sodium tripolyphosphate, potassium carbonate, lithium carbonate, potassium feldspar, zinc oxide and copper oxide in a specific mass ratio. The preparation comprises the steps of raw material mixing, high-temperature smelting under pure oxygen condition, wire drawing detection and rapid cooling. The titanium lake blue face glaze is completely free of fluorinated salt and nitrate, avoids fluorine emission and environmental protection equipment blockage problems from the source, the fluorine content of the product is not detected through detection, meets the requirements of the EU REACH regulation, has good porcelain surface, gloss and low-temperature sintering adaptability, is suitable for a steel plate substrate, has a sintering temperature of 780-830 DEG C, and can be used for the production of green and environment-friendly enamel products.

Description

TECHNICAL FIELD

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

[0002] The steel plate enamel titanium lake blue face glaze needs to meet four core indexes of high brightness of the enamel surface, bright color, good opalescence and firing temperature (780-830℃). The traditional formula relies on fluorinated salt (fluorite / fluorosilicate accounts for 1-12%) to realize fluxing, improve opalescence and other performances. The fluorinated salt is not an "optional" additive in the traditional enamel face glaze, but an "indispensable" skeleton component. Since the fluorinated salt has multiple synergies of reducing the melting temperature, improving the opalescence and wettability, simply and roughly removing the fluorinated salt is equivalent to removing the load-bearing wall of the building, which leads to not "performance decline", but "collapse" of the entire enamel system. Any fluorine-free attempt must be based on finding or inventing a new material 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 confirmed 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 20mg / 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 close-together promoting component, is easy to produce nitrogen oxides (NO x ) in the high-temperature decomposition process, which also faces environmental pressure. Currently, the denitration of enamel glaze has solved the problem of nitrogen oxide emission (such as CN114368912B, CN114315150B, CN114315151B, etc.), and further realization of fluorine-free, promotion of fluorine-free and nitrate-free system research and development 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 therefrom, CN115626774A relates to a soft light skin ceramic rock plate and a preparation method thereof, CN112979271A relates to a preparation method of 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 preparation method thereof. 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, the present application provides a steel plate enamel titanium lake blue face glaze without fluorinated salt and nitrate, as well as a preparation method and application thereof.

[0013] The titanium lake blue enamel for steel plates of the present invention, which is free of fluoride salts and nitrates, is composed of the following components by weight: 25-40 parts quartz, 18-25 parts anhydrous borax, 14-18 parts titanium dioxide, 2-4 parts soda ash, 1-2 parts magnesium carbonate, 2-6 parts sodium tripolyphosphate, 4-8 parts potassium carbonate, 2-3 parts lithium carbonate, 8-15 parts potassium feldspar, 1-2 parts zinc oxide, and 1.5-3 parts copper oxide.

[0014] Further, the composition includes 32-40 parts quartz, 22-24 parts anhydrous borax, 15-17 parts titanium dioxide, 2.8-3.5 parts soda ash, 1.3-1.7 parts magnesium carbonate, 2.5-4.5 parts sodium tripolyphosphate, 4-6 parts potassium carbonate, 2.5-3 parts lithium carbonate, 8-12 parts potassium feldspar, 1.2-1.8 parts zinc oxide, and 2.3-2.8 parts copper oxide.

[0015] Furthermore, the mass percentage of SiO2 in quartz is ≥99%, the mass percentage of SiO2 in potassium feldspar is ≥71%, K2O+Na2O is ≥11%, the mass percentage of TiO2 in titanium dioxide is ≥99%, and zinc oxide is obtained by oxidation after distillation of metallic zinc, with a mass purity of ≥99.7%.

[0016] The preparation method of the above-mentioned titanium lake blue enamel for steel plates that is free of fluoride salts and nitrates includes the following steps:

[0017] (1) Weigh each component raw material according to the above mass proportions;

[0018] (2) Stir and mix the raw materials described in step (1) until they are evenly mixed;

[0019] (3) Add the mixed material into the melting furnace and melt it under pure oxygen conditions. The melting temperature is controlled at 1300±10℃.

[0020] (4) After the material described in step (3) is completely melted, a borosilicate glass body is obtained. The molten borosilicate glass body is then drilled and quickly drawn into a glass wire of 1.2 to 1.5 meters for testing. The testing requirement is that the glass wire is melted without knots within 1 meter for 2-5 minutes to complete the melting process.

[0021] (5) The molten borosilicate glass body is rapidly cooled to obtain the product.

[0022] Furthermore, in step (5), the rapid cooling is achieved by water quenching or tableting.

[0023] The above-mentioned titanium blue enamel for steel plates, which is free of fluoride salts and nitrates, is applied to blanks with steel plates as the base material, and the firing temperature of the finished product is 780-830℃.

[0024] The application increases the amount of titanium dioxide and zinc oxide in the enamel formula of steel plate enamel titanium lake blue face glaze, strengthens the synergistic effect of zinc oxide and titanium dioxide, reduces the viscosity of liquid phase, and promotes the coloring of components such as copper oxide, increases the amount of phosphate, on the one hand, the phosphate provides [PO4] 3- group to promote feldspar nucleation, on the other hand, to form a eutectic complex fluxing system of "multinary carbonate + phosphate + borate" to strengthen fluxing, and the components work together to improve the comprehensive performance of the enamel surface gloss, bright color, opacity (lactescence performance) and firing performance.

[0025] The application has the following beneficial effects:

[0026] (1) The fluoride is discharged at an ultra-low standard;

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

[0028] (3) The problem of blocking of the end environmental protection equipment is solved: the application completely removes fluoride (fluorite, sodium fluorosilicate, etc.), eliminates the source of fluoride salt crystallization from the source, and solves the problem of blocking of the end environmental protection equipment. 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) Good firing adaptability: the eutectic complex fluxing system (multinary carbonate + phosphate + borate) interacts with other components, so that the firing temperature is stably controlled at 780-830℃, and the enamel surface has good leveling property.

[0030] (5) The amount of phosphate is increased, the phosphate provides [PO4] 3- group to promote feldspar nucleation, the amount of titanium dioxide is increased, and zinc oxide is added to strengthen the synergistic effect, ZnO / TiO2 reduces the viscosity of liquid phase, and promotes the coloring of components such as copper oxide, and the components work together to improve the comprehensive performance of the enamel surface gloss, bright color, opacity (lactescence performance) and firing performance. BRIEF DESCRIPTION OF DRAWINGS

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

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

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

[0034] Batching: using automatic batching, mixing system. The system is fully automated computer control, with accurate weighing, uniform mixing, high efficiency of batching characteristics.

[0035] Melting: using automatic feeding system, automatic pure oxygen combustion control system, automatic discharging system.

[0036] Packaging: using automatic packaging system.

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

[0038] Example 1

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

[0040] Quartz 30 parts, zero water borax 24 parts, titanium dioxide 18 parts, soda ash 2 parts, magnesium carbonate 2 parts, sodium tripolyphosphate 2 parts, potassium carbonate 4.5 parts, lithium carbonate 2.7 parts, potassium feldspar 15 parts, zinc oxide 1 part, copper oxide 1.5 parts;

[0041] The mass fraction of SiO2 in quartz is ≥99%, the mass fraction of SiO2 in potassium feldspar is ≥71%, K2O+Na2O is ≥11%, the mass fraction of TiO2 in titanium dioxide is ≥99%, and the mass purity of zinc oxide prepared by distillation of metallic zinc and oxidation 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 1.2-1.5 meter glass filament for detection, with the detection requirement being that no knot continues to melt for 5 minutes within 1 meter of the glass filament.

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

[0046] 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 titanium lake blue enamel surface of the steel plate enamel without fluorinated salt and nitrate is smooth and delicate, the appearance has no obvious defects, the luster is excellent, the color phase is stable, and the product quality meets the requirements of enterprise standards.

[0047] Example 2

[0048] The preparation process of this embodiment is basically the same as that of Example 1, except that:

[0049] The mass parts of each component in step (1) are: quartz 25 parts, zero-water borax 18 parts, titanium white 14 parts, soda ash 4 parts, magnesium carbonate 1 part, sodium tripolyphosphate 6 parts, potassium carbonate 8 parts, lithium carbonate 2 parts, potassium feldspar 13 parts, zinc oxide 2 parts, and copper oxide 3 parts.

[0050] In step (5), the borosilicate glass body is quenched by using a tabletting process.

[0051] Example 3

[0052] The preparation process of this example is basically the same as that of Example 1, except that:

[0053] The mass parts of each component in step (1) are: quartz 32 parts, zero-water borax 22 parts, titanium white 17 parts, soda ash 2.8 parts, magnesium carbonate 1.7 parts, sodium tripolyphosphate 4.5 parts, potassium carbonate 4 parts, lithium carbonate 3 parts, potassium feldspar 8 parts, zinc oxide 1.2 parts, and copper oxide 2.3 parts.

[0054] Example 4

[0055] The preparation process of this example is basically the same as that of Example 1, except that:

[0056] The mass parts of each component in step (1) are: quartz 40 parts, zero-water borax 24 parts, titanium white 15 parts, soda ash 3.5 parts, magnesium carbonate 1.3 parts, sodium tripolyphosphate 2.5 parts, potassium carbonate 6 parts, lithium carbonate 2.5 parts, potassium feldspar 12 parts, zinc oxide 1.8 parts, and copper oxide 2.8 parts.

[0057] Comparative Example 1

[0058] The rest is the same as Example 1, except that the mass parts of each component in step (1) are: quartz 30.0 parts, zero-water borax 22 parts, titanium oxide 16 parts, sodium fluorosilicate 8.5 parts, potassium feldspar 10 parts, magnesium carbonate 2 parts, sodium tripolyphosphate 1.3 parts, lithium carbonate 2.2 parts, and copper oxide 1.5 parts.

[0059] The test results of the products obtained in the above examples and comparative examples are shown in Table 1 below.

[0060] Table 1 Test results of products obtained in each example and comparative example

[0061]

[0062] The above examples and detection results prove that the enamel titanium lake blue 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, the properties (gloss, bright color, opacity, sintering temperature) of the obtained product meet the requirements of the enamel titanium lake blue 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 SVHC (substance of very high concern) of the European Union REACH regulation is met, and the technical problems of the existing enamel titanium lake blue face glaze of the steel plate, i.e. the fluorinated gas emission pollutes the environment in the production process and the fluorinated salt emission blocks the environmental protection treatment facilities, are fundamentally solved.

Claims

1. Steel plate enamel titanium lake blue face glaze free of fluorinated salts and free of nitrates, characterized in that, The formula is composed of the following components in parts by mass: quartz 25-40 parts, zero-water borax 18-25 parts, titanium white 14-18 parts, soda ash 2-4 parts, magnesium carbonate 1-2 parts, sodium tripolyphosphate 2-6 parts, potassium carbonate 4-8 parts, lithium carbonate 2-3 parts, potassium feldspar 8-15 parts, zinc oxide 1-2 parts, and copper oxide 1.5-3 parts.

2. The fluorine-free salt-free and nitrate-free steel panel enamel titanium lake blue face enamel according to claim 1, characterized in that, Quartz 32-40 parts, zero-water borax 22-24 parts, titanium white 15-17 parts, soda ash 2.8-3.5 parts, magnesium carbonate 1.3-1.7 parts, sodium tripolyphosphate 2.5-4.5 parts, potassium carbonate 4-6 parts, lithium carbonate 2.5-3 parts, potassium feldspar 8-12 parts, zinc oxide 1.2-1.8 parts, and copper oxide 2.3-2.8 parts.

3. The fluorine-free salt-free and nitrate-free steel panel enamel titanium lake blue face enamel according to claim 1 or 2, characterized in that, The mass ratio of SiO2 in quartz is ≥99%.

4. The fluorine-free salt-free and nitrate-free steel panel enamel titanium lake blue face enamel according to claim 1 or 2, characterized in that, The mass ratio of SiO2 in potassium feldspar is ≥71%, and K2O+Na2O is ≥11%.

5. The fluorine-free salt-free and nitrate-free steel panel enamel titanium lake blue face enamel according to claim 1 or 2, characterized in that, The mass ratio of TiO2 in titanium white is ≥99%.

6. The fluorine-free salt-free and nitrate-free steel panel enamel titanium lake blue face enamel according to 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 titanium lake blue face enamel 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) obtaining a borosilicate glass body after the material in step (3) is completely melted, and the molten borosilicate glass body is drawn into a 1.2-1.5 meter glass filament for detection, with the detection requirement being that no knot is observed within 1 meter of the glass filament, and the melting is completed after 2-5 minutes of continuous melting; (5) rapidly cooling the melted borosilicate glass body, and obtaining the product.

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 sheet enamel titanium lake blue face glaze free of fluorinated salts and nitrates according to any one of claims 1 to 6, characterized in that, The product is applied to a blank with a steel plate as a base body, and the firing temperature of the finished product is 780-830℃.

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