Preparation method of lead-free metal luster glaze

Abstract

The application discloses a preparation method of a lead-free metal luster glaze. 2+ , Fe 3+ , Mn 2+ , etc.) are uniformly distributed in the network structure, so that the glaze layer is endowed with environmental protection, high gloss and color stability characteristics. The application not only effectively reduces the production cost, but also effectively solves the significant problems existing in the environmental protection and safety level of the traditional lead-containing glaze, and can be widely applied in the fields of art, daily use and building ceramics.

Description

Technical Field

[0001] This invention relates to the field of ceramic glaze technology, and in particular to a method for preparing a lead-free metallic glaze. Background Technology

[0002] Metallic glazes have a wide range of applications in art, daily-use, and architectural ceramics. Traditional metallic glazes rely on lead-containing fluxes. While lead-containing glazes impart excellent gloss and color to ceramic products, lead poses a potential threat to human health and environmental safety. In the trend of comprehensive resource utilization, many industrial wastes contain usable components. Recycling these components during glaze preparation can not only achieve resource recovery from waste but also effectively reduce raw material procurement costs. The key challenge currently facing the ceramics industry is developing a new glaze system to replace traditional lead-containing systems. By rationally introducing recycled resources and optimizing the formula, lead-free metallic glazes with environmentally friendly properties, excellent gloss, and good color stability can be produced to meet the urgent needs of related fields for such ceramic products. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for preparing lead-free metallic luster glaze. This method involves introducing lead-free raw materials such as calcium borate frit and recycling steel slag to construct a formulation system that promotes the formation of coloring ions (Co... 2+ Fe 3+ Mn 2+ The glaze is evenly distributed in the network structure, thereby giving it environmentally friendly, high gloss and color stability properties, and effectively reducing costs and solving environmental pollution problems.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] This invention provides a method for preparing a lead-free metallic luster glaze. The raw material composition of the lead-free metallic luster glaze is as follows: calcium borate frit 30-40 wt%, quartz 15-19 wt%, calcined kaolin 15-25 wt%, steel slag 15-20 wt%, manganese oxide 2-4 wt%, zinc oxide 2-3 wt%, cobalt oxide 2-3 wt%, and titanium dioxide 2-5 wt%. The chemical composition of the calcium borate frit is: SiO2 0.13-2.16 wt%, Al2O3 0.11-0.58 wt%, MgO 0.24-0.56 wt%, CaO 30.63-35.46 wt%, B2O3 45.68-53.16 wt%, IL 11.38–15.98 wt%; The chemical composition of the steel slag is: SiO2 14.36–18.45 wt%, Al2O3 9.65–12.56 wt%, Fe2O3 15.69–20.18 wt%, Na2O 0.01–0.32 wt%, MgO 8.46–12.57 wt%, CaO 35.69–40.76 wt%, TiO2 1.42–3.56 wt%, IL 3.34–6.18 wt%; The preparation method includes the following steps:

[0006] (1) After weighing and mixing the raw materials according to the above composition, add them to a ball mill for wet ball milling, and then sieve to obtain glaze slurry;

[0007] (2) The glaze slurry is applied to the surface of the unglazed body by dipping or spraying to obtain a body with a glaze layer; then the temperature is raised to 1140-1170℃ at a rate of 3℃ / min for sintering treatment, and the holding time is 1-2h. After natural cooling, a lead-free metallic luster glaze is obtained; the crystal phase composition of the lead-free metallic luster glaze contains a platy anorthite crystal phase and a granular titanite crystal phase. The orderly arrangement of the platy anorthite and the diffuse distribution of the granular titanite form a micro-nano composite structure; the gloss of the lead-free metallic luster glaze is 92-98 GU.

[0008] Further, in step (1) of the present invention, ball milling is performed at a mass ratio of material:ball:water = 1:1.8-2.3:1-1.4, and the ball milling time is 30-60 minutes. In step (2), the thickness of the glaze layer is 0.8-1.5 mm.

[0009] The present invention has the following beneficial effects:

[0010] (1) This invention introduces calcium borate frit into the formulation system. The calcium borate frit undergoes high-temperature thermal decomposition to generate boron-containing anionic groups and calcium ions. The boron-containing anionic groups combine with silicon-oxygen tetrahedra to jointly construct a flexible and open glass network structure, which facilitates the entry of coloring ions into the network structure; furthermore, calcium ions in the network affect the local electric field, working synergistically with the network structure to guide the coloring ions (Co).2+ Fe 3+ Mn 2+ (etc.) are evenly distributed, thereby enhancing the color expression of the glaze.

[0011] (2) In the formulation system of this invention, calcium ions combine with titanium, aluminum, and silicon ions under high temperature to form anorthite (CaAl2Si2O8) and titanite (CaTiSiO5) crystal phases. The boron-containing components in the system can reduce the melting temperature and viscosity of the glaze, promoting the precipitation of anorthite and titanite crystal phases. Anorthite has a regular crystal structure and good optical properties, and its smooth surface can effectively reflect light; titanite has a complex crystal structure, with high dispersion and high refractive properties, and its regular surface can efficiently reflect light. The orderly arrangement of the platy anorthite and the diffuse distribution of the granular titanite work synergistically to form a micro-nano composite structure, which greatly increases the reflection of the glaze surface and significantly improves the gloss of the glaze surface.

[0012] (3) This invention introduces lead-free raw materials such as calcium borate frit and recycles steel slag to construct a formulation system, which not only effectively reduces production costs but also solves the significant environmental and safety problems of traditional lead-containing glazes. In addition, steel slag can provide ions such as Ca²⁺, Al³⁺, and Fe³⁺ that play a key role in the system. These ions can participate in complex reactions within the system, regulate system performance, and achieve a good effect of synergistic optimization of environmental protection, economy, and performance. Attached Figure Description

[0013] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings:

[0014] Figure 1 These are microscopic images of the lead-free metallic luster glaze obtained in the embodiments of the present invention (a: arrangement of the composite crystal phases of anorthite and titanosphene; b: anorthite crystal phase diagram; c: titanosphene crystal phase diagram).

[0015] Figure 2 These are surface appearance diagrams of the lead-free metallic glaze obtained in the embodiments of the present invention (a: top view; b: oblique view). Detailed Implementation

[0016] This invention discloses a method for preparing a lead-free metallic luster glaze. The raw material composition of the lead-free metallic luster glaze is as follows: 30-40 wt% calcium borate frit, 15-19 wt% quartz, 15-25 wt% calcined kaolin, 15-20 wt% steel slag, 2-4 wt% manganese oxide, 2-3 wt% zinc oxide, 2-3 wt% cobalt oxide, and 2-5 wt% titanium dioxide. The preparation method comprises the following steps:

[0017] (1) After weighing and mixing the raw materials according to the above composition, add them to the ball mill and perform wet ball milling at a mass ratio of material:ball:water = 1:1.8~2.3:1~1.4. The ball milling time is 30~60 minutes. After sieving, the glaze slurry is obtained.

[0018] (2) Apply the above glaze slurry to the surface of the unglazed body by dipping or spraying to obtain a body with a glaze layer (thickness of 0.8 to 1.5 mm); then heat it to 1140 to 1170 °C at a rate of 3 °C / min for sintering treatment, hold it for 1 to 2 hours, and after natural cooling, a lead-free metallic glaze is obtained.

[0019] The raw material composition of the lead-free metallic glaze in each embodiment is shown in Table 1. The steel slag used in the raw materials comes from Wuhan Iron and Steel Group Co., Ltd., and the manganese oxide, zinc oxide, cobalt oxide, and titanium dioxide are all chemically pure raw materials (MnO2, ZnO, CoO, TiO2 ≥ 99.5%). The chemical composition of the remaining raw materials is shown in Table 2.

[0020] Table 1. Raw material composition (wt%) of lead-free metallic luster glazes in various embodiments of the present invention

[0021]

[0022] Table 2 Chemical composition (wt%) of raw materials used in the embodiments of the present invention

[0023]

[0024] The preparation process parameters for each embodiment are shown in Table 3.

[0025] Table 3. Preparation process parameters of various embodiments of the present invention

[0026]

[0027] Comparative Example 1:

[0028] Using an equal amount of lead-boron frit instead of calcium borate frit as Comparative Example 1, and with the other conditions the same as in Examples 1, 2, 3, and 4, four sets of experiments were conducted.

[0029] Comparative Example 2:

[0030] Using no steel slag as the control example, four sets of experiments were conducted under the same conditions as in Examples 1, 2, 3, and 4.

[0031] Comparative Example 3:

[0032] Four sets of experiments were conducted with no titanium dioxide added as Comparative Example 3, and the other conditions were the same as in Examples 1, 2, 3, and 4.

[0033] Performance testing:

[0034] The gloss of the metallic glazes obtained in Examples 1-4 and Comparative Examples 1-3 was measured and the surface quality was evaluated. The gloss of the glazes was tested using a WGG60A gloss meter.

[0035] The performance indicators of the glazes obtained in the embodiments and comparative examples of the present invention are shown in Table 4.

[0036] Table 4 Performance indicators of the glaze obtained from the embodiments and comparative examples of the present invention

[0037]

[0038] Note: The performance indicators for each comparative example are the average values ​​of the four experimental groups.

[0039] like Figure 1 As shown, the tabular crystals are anorthite, and the white granular crystals are titanite; the tabular anorthite is arranged in an orderly manner, while the granular titanite is dispersed. Table 4 shows that the gloss levels of Examples 1-4 are all greater than 90 GU, indicating excellent glaze performance (see Table 4). Figure 2 Comparative Example 1 is a traditional lead-containing system, whose gloss and glaze quality are not as good as those of the embodiments of the present invention; in Comparative Example 2, the lack of steel slag to stabilize the formula system leads to a decrease in glaze quality and gloss; in Comparative Example 3, the lack of titanium element prevents the formation of titanium sphene (CaTiSiO5) crystal phase, resulting in a gloss level far lower than that of the embodiments of the present invention.

Claims

1. A method for preparing a lead-free metallic luster glaze, characterized in that: The raw material composition of the lead-free metallic luster glaze is as follows: calcium borate frit 30-40 wt%, quartz 15-19 wt%, calcined kaolin 15-25 wt%, steel slag 15-20 wt%, manganese oxide 2-4 wt%, zinc oxide 2-3 wt%, cobalt oxide 2-3 wt%, and titanium dioxide 2-5 wt%. The chemical composition of the calcium borate frit is: SiO2 0.13-2.16 wt%, Al2O3 0.11-0.58 wt%, MgO 0.24-0.56 wt%, CaO 30.63-35.46 wt%, B2O3 45.68-53.16 wt%, and I1 11.38-15.98 wt%. The chemical composition of the steel slag is: SiO2 14.36-18.45 wt%, Al2O3 9.65-12.56 wt%, Fe2O3 15.69-20.18 wt%, and Na2O. 0.01–0.32 wt%, MgO 8.46–12.57 wt%, CaO 35.69–40.76 wt%, TiO2 1.42–3.56 wt%, IL 3.34–6.18 wt%; The preparation method includes the following steps: (1) After weighing and mixing the raw materials according to the above composition, add them to a ball mill for wet ball milling, and then sieve to obtain glaze slurry; (2) The glaze slurry is applied to the surface of the unglazed body by dipping or spraying to obtain a body with a glaze layer; then the temperature is raised to 1140-1170℃ at a rate of 3℃ / min for sintering treatment, and the holding time is 1-2h. After natural cooling, a lead-free metallic luster glaze is obtained; the crystal phase composition of the lead-free metallic luster glaze contains a platy anorthite crystal phase and a granular titanite crystal phase. The orderly arrangement of the platy anorthite and the diffuse distribution of the granular titanite form a micro-nano composite structure; the gloss of the lead-free metallic luster glaze is 92-98 GU.

2. The method for preparing lead-free metallic luster glaze according to claim 1, characterized in that: In step (1), ball milling is performed at a mass ratio of material:ball:water = 1:1.8 to 2.3:1 to 1.4, and the ball milling time is 30 to 60 minutes.

3. The method for preparing lead-free metallic luster glaze according to claim 1, characterized in that: The thickness of the glaze layer in step (2) is 0.8 to 1.5 mm.

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