Method for monitoring dealkalization uniformity of high-aluminum float glass

Abstract

The invention relates to the technical field of float glass production, and discloses a high-aluminum float glass dealkalization uniformity monitoring method which comprises the following steps: S1, cutting glass subjected to dealkalization treatment, placing the cut glass in a container, soaking the cut glass in a weak acid solution, cleaning the soaked glass, detecting the state of roller marks on the surface of the glass, and increasing the usage amount of SO2 in a tin bath when the occurrence proportion of the roller marks on the glass exceeds 10%; s2, soaking the glass in a reinforcing acid solution, cleaning and detecting the dimness state of the glass, and reducing the usage amount of SO2 in a tin bath when the dimness proportion exceeds 10% or above; through the operation, the dealkalization amount of the glass is controlled. According to the method, the roller marks, the obscuration condition and the proportion are generated after glass soaking treatment, dealkalization on the surface of the glass is monitored, the dealkalization uniformity can be effectively controlled, and the method is simple in technological process, does not need to add expensive equipment and is easy to apply and popularize.

Description

Technical Field

[0001] The present invention relates to the technical field of float glass, and particularly relates to a method for monitoring the dealkalization uniformity of high-aluminum float glass. Background Art

[0002] The float process is one of the production processes of high-aluminum silicate glass. A glass dealkalization process is often set in a float glass production line, that is, a sulfur dioxide pipeline is set between transition rollers or at the entrance of an annealing furnace. When the glass passes through the sulfur dioxide pipeline at a high temperature, Na2O on the glass surface reacts with acidic SO2 to form substances such as Na2SO3 or Na2SO4. On the one hand, it can reduce the surface scratches of the glass caused by impurities such as tin slag during the roller transmission process of the glass sheet. Second, through the adjustment of the dealkalization process, the difference in the composition of both sides of the float glass is reduced, and the warpage of the chemically tempered glass is improved.

[0003] Currently, the width of the glass plate in a high-aluminum glass production line is generally 2.5 meters to 3.5 meters, and the width of the glass plate is relatively large; when the sulfur dioxide input amount is too small, there is uneven dealkalization distribution of the glass in the plate width direction, resulting in defects such as scratches in some areas of the glass. At this time, the sulfur dioxide input amount is increased to improve the dealkalization uniformity of the glass. However, when the sulfur dioxide input amount is excessive, it causes waste of sulfur dioxide and damage to equipment. CN 117756377 A "Method for Controlling the Warpage Defects of Ultra-Thin Float Electronic Glass for Tempering" mentions controlling the warpage of tempered glass by adjusting the sulfur dioxide concentration. Therefore, to meet the requirements of different products, it is necessary to adjust the sulfur dioxide concentration to achieve different dealkalization amounts on the glass surface. Liu Shimin et al. mentioned in "Research on the Application of Sulfur Dioxide Gas in the Float Line" that an X-ray fluorescence spectrometer (XRF) is used for measurement and an X-ray energy spectrometer is used for analysis of the application of sulfur dioxide, but this method cannot accurately measure the change of sulfur dioxide. CN114002248A discloses a method for monitoring and controlling the sulfur dioxide consumption in a float glass production line. This method combines monitoring the sulfur dioxide consumption and using expensive equipment such as a scanning electron microscope to detect the film thickness to determine the uniformity of the sulfur dioxide layer. It requires expensive detection equipment and is difficult to be widely applied in a high-aluminum float glass production line. In addition, due to the uneven dealkalization in the plate width direction of the glass plate, there is a large difference in the warpage in the plate width direction of the glass plate. Therefore, it is necessary to develop a monitoring method for efficiently detecting the dealkalization uniformity in the plate width direction of the glass plate. Summary of the Invention

[0004] The present invention provides a method for monitoring the dealkalization uniformity of high-aluminum float glass, which can timely adjust the parameters of the dealkalization process, ensure the dealkalization uniformity, and improve the quality of the glass.

[0005] The technical solution of the present invention is to provide a method for monitoring the dealkalization uniformity of high-aluminum float glass, including the following steps: S1. Cut the de-alkalized glass, place it in a container, soak it in a weak acid solution, clean it, and then detect the state of roller marks on the glass surface. When the proportion of roller marks on the glass exceeds 10%, increase the usage amount of SO2 in the tin bath; S2. Cut the de-alkalized glass, place it in a container, soak it in a strong acid solution, clean it, and detect the frosted state of the glass. When the frosting proportion exceeds 10%, reduce the usage amount of SO2 in the tin bath; Through the above operations, the control of the de-alkalization amount of the glass is achieved.

[0006] Optionally, during the de-alkalization treatment, control the flow rate of SO2 to be 3 L / min to 300 L / min, the volume concentration of SO2 to be 85% to 95%, and the de-alkalization temperature to be 450 °C to 750 °C.

[0007] Optionally, in S1, the cutting size is not limited and should be suitable for detection and observation.

[0008] Optionally, the weak acid solution is oxalic acid, acetic acid, citric acid, or a combination thereof.

[0009] Optionally, the concentration of oxalic acid is 1 to 10 wt%, the concentration of acetic acid is 0 to 10 wt%, and the concentration of citric acid is 0 to 5 wt%.

[0010] Optionally, the soaking time of the weak acid solution is at least 120 seconds, and the soaking temperature of the weak acid solution is at least 50 °C.

[0011] Optionally, the strong acid solution includes hydrochloric acid, sulfuric acid, and hydrofluoric acid.

[0012] Optionally, the concentration of hydrofluoric acid is 1.0 to 2.5 wt%, the concentration of hydrochloric acid is 5% to 20 wt%, and the concentration of sulfuric acid is 5 - 10 wt%.

[0013] Optionally, the soaking time of the glass in the strong acid solution is at least 30 s, and the soaking temperature is at least 30 °C.

[0014] Optionally, the detection method for the roller marks and frosting is to first irradiate the glass surface with a strong light lamp with an illuminance of 6000 Lux at an angle of 20 °C. The human eye forms an angle of about 45 degrees with the glass plane, and the distance between the person and the sample is about 300 mm. The human eye observes the roller marks and frosting on the glass surface qualitatively; use a vernier caliper to quantitatively measure the width of the marked roller marks; use a haze meter to test the frosted glass sample.

[0015] The present invention has the following beneficial effects: The research of the present invention has found that the de-alkalization process will change the surface composition of the glass. When the de-alkalization is insufficient, there are relatively more alkali metal oxides in the de-alkalized layer on the glass surface, the surface hardness is relatively low, and the sulfur dioxide layer on the surface cannot protect the glass. During the roller transportation process, roller marks are formed on the glass surface due to the friction of the rollers. When treated with a weak acid solution, the roller marks on the glass surface become prominent, and at this time, the amount of de-alkalization needs to be increased. When the de-alkalization is excessive, the alkali metal content on the glass surface is significantly reduced, and the silica content in the de-alkalized layer of the glass is too high. When the glass is immersed in a strong acid solution, the silica on the glass surface is affected by the strong acid and forms fluorosilicates with strong adhesion to the glass surface, which are not easy to fall off, resulting in uneven subsequent etching and causing the glass to become hazy.

[0016] Through the roller marks and haziness conditions and their proportions that appear after the glass is immersed in the treatment, the present invention monitors the de-alkalization of the glass surface, can effectively control the uniformity of de-alkalization, and this method has a simple process flow, does not require adding expensive equipment, and is easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram for detecting the roller marks and haziness of the glass. DETAILED DESCRIPTION OF THE INVENTION

[0018] Unless otherwise specified, the experimental methods in the following examples are all conventional methods. Unless otherwise specified, the materials used in the following examples are all commercially available products.

[0019] In the following examples and comparative examples, the qualitative and quantitative detection methods for roller marks and haziness are as follows: 1) Use a strong light with an illuminance of 6000 Lux to irradiate the glass surface at an angle of 20°C. The human eye forms an angle of about 45 degrees with the glass plane, and the distance between the person and the sample is about 300 mm, as specifically shown in Figure 1 ; Visually observe the roller marks and haziness on the glass surface.

[0020] 2) Use a vernier caliper to measure the width of the marked roller marks and calculate the proportion of roller marks; use a haze meter TH-100 to test the hazy glass samples and calculate the haziness proportion.

[0021] Among them, the width of the roller marks should be ≤0.5 mm; the haze value after the glass becomes hazy should be ≤0.4%.

[0022] The following will describe the implementation plan of the present invention in detail in combination with the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention.

[0023] Example 1 Decalcification process: Control the SO2 flow rate at 5 L / min, the SO2 concentration at 90%, and the temperature range of the decalcification process at 630°C to 750°C; S1. Cut the glass after decalcification treatment and soak it in a weak acid solution in a container. The weak acid solution is 3 wt% oxalic acid, 2 wt% citric acid, and 95% water. The soaking time is 180 seconds, the soaking temperature is 53°C. After soaking, wash it and detect the roller mark state on the glass surface. S2. Cut the glass after decalcification treatment and soak it in a strong acid solution in a container. The strong acid solution is 2.5 wt% hydrofluoric acid, 20 wt% hydrochloric acid, 15 wt% sulfuric acid, and 62.5 wt% water. The soaking time is 120 seconds, the soaking temperature is 35°C. Then wash it and detect the fogging state of the glass. Glass test results: The roller marks on the surface in the width direction of the glass plate are 100%, and the fogging phenomenon on the surface in the width direction of the glass plate is 0%. The width value of the glass roller marks is between 3 and 6 mm. Select unfogged samples to test the haze value of 0 to 0.04%. According to the test results, it is necessary to increase the SO2 usage in the tin bath.

[0024] Example 2 The main operations in this example are the same as those in Example 1: Decalcification process: Control the SO2 flow rate at 20 L / min, the SO2 concentration at 90%, and the temperature range of the decalcification process at 630°C to 750°C; Glass treatment process: 5 wt% oxalic acid, 4 wt% citric acid, and 91% water in the weak acid solution. The soaking time is 180 seconds, the soaking temperature is 53°C. 2 wt% hydrofluoric acid, 19 wt% hydrochloric acid, 15 wt% sulfuric acid, and 64 wt% water in the strong acid solution. The soaking time is 90 seconds, the soaking temperature is 35°C.

[0025] Glass test results: The proportion of roller marks on the surface in the width direction of the glass plate is 40%, and the proportion of the fogging phenomenon on the surface in the width direction of the glass plate is 0%.

[0026] The width value of the glass roller marks is 1 to 3 mm. Select unfogged samples to test the haze value of 0 to 0.04%. According to the test results, it is necessary to increase the SO2 usage in the tin bath.

[0027] Example 3 The main operations are the same as those in Example 1, and the difference lies in: Decalcification process: Control the SO2 flow rate at 50 L / min, the SO2 concentration at 90%, and the temperature range of the decalcification process at 630°C to 750°C; Glass treatment process: In a weak acid solution, there is 7 wt% oxalic acid, 2 wt% citric acid, 1 wt% acetic acid and 90% water, the soaking time is 480 seconds, and the soaking temperature is 56°C. In a strong acid solution, there is 2.5 wt% hydrofluoric acid, 20 wt% hydrochloric acid, 15 wt% sulfuric acid and 64 wt% water, the soaking time is 90 seconds, and the soaking temperature is 35°C.

[0028] Glass test results: The proportion of roller marks on the surface in the width direction of the glass plate is 0%, and the proportion of the surface being hazy in the width direction of the glass plate is 0%.

[0029] The width value of the glass roller mark sample is 0, and the haze value of the non-hazy sample selected for testing is 0 - 0.04%.

[0030] Example 4 Decalcification process: Control the SO2 flow rate at 150 L / min, the SO2 concentration is 90%, and the decalcification process temperature range is 630°C - 750°C.

[0031] Glass treatment process: In a weak acid solution, there is 8 wt% oxalic acid, 1 wt% acetic acid and 91% water, the soaking time is 600 seconds, and the soaking temperature is 56°C. In a strong acid solution, there is 1.5 wt% hydrofluoric acid, 20 wt% hydrochloric acid, 15 wt% sulfuric acid and 64.5 wt% water, the soaking time is 60 seconds, and the soaking temperature is 35°C.

[0032] Glass test results: The proportion of roller marks on the surface in the width direction of the glass plate is 0%, and the proportion of the surface being hazy in the width direction of the glass plate is 10%.

[0033] The width value of the glass roller mark sample is 0, and the glass haze value is 0.4 - 0.6%. According to the test results, it is necessary to reduce the SO2 usage amount in the tin bath.

[0034] Example 5 Decalcification process: Control the SO2 flow rate at 300 L / min, the SO2 concentration is 90%, and the decalcification process temperature range is 630°C - 750°C; Glass treatment process: In a weak acid solution, there is 8 wt% oxalic acid, 2 wt% acetic acid and 90% water, the soaking time is 600 seconds, and the soaking temperature is 56°C. In a strong acid solution, there is 1.5 wt% hydrofluoric acid, 15 wt% hydrochloric acid, 20 wt% sulfuric acid and 64.5 wt% water, the soaking time is 30 seconds, and the soaking temperature is 35°C.

[0035] Glass test results: The proportion of roller marks on the surface in the width direction of the glass plate is 0%, and the proportion of the surface being hazy in the width direction of the glass plate is 70%.

[0036] The width value of the glass roller printed sample is 0, and the haze value of the glass is 0.6 - 0.8%. According to the test results, the SO2 usage in the tin bath needs to be reduced.

[0037] Example 6 De - alkalization process: Control the SO2 flow rate at 500 L / min, the SO2 concentration at 90%, and the temperature range of the de - alkalization process at 630℃ - 750℃; Glass treatment process: In a weak acid solution, it contains 8 wt% oxalic acid, 2 wt% acetic acid, and 90% water, the soaking time is 600 seconds, and the soaking temperature is 56℃. In a strong acid solution, it contains 1.5 wt% hydrofluoric acid, 15 wt% hydrochloric acid, 20 wt% sulfuric acid, and 64.5 wt% water, the soaking time is 30 seconds, and the soaking temperature is 35℃.

[0038] Glass test results: The proportion of roller prints on the surface in the width direction of the glass plate is 0%, and the proportion of the surface being hazy in the width direction of the glass plate is 100%.

[0039] The width value of the glass roller printed sample is 0, and the haze value of the glass is 0.8 - 1.4%. According to the test results, the SO2 usage in the tin bath needs to be reduced.

[0040] The above embodiments describe the preferred embodiments of the present invention, but the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other combinations of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent shall be subject to the appended claims.

Claims

1. A method for monitoring the uniformity of alkali removal in high-aluminum float glass, characterized in that, It includes the following steps: S1. Cut the de-alkalized glass and soak it in a weak acid solution in a container. After cleaning, detect the state of roller marks on the glass surface. When the proportion of roller marks on the glass exceeds 10%, increase the usage amount of SO2 in the tin bath; S2. Cut the de-alkalized glass and soak it in a strong acid solution in a container. After cleaning, detect the foggy state of the glass. When the foggy proportion exceeds 10% or more, reduce the usage amount of SO2 in the tin bath; Through the above operations, the control of the de-alkalization amount of the glass is achieved.

2. The monitoring method according to claim 1, wherein: During the de-alkalization treatment, control the flow rate of SO2 to be 3 L / min to 300 L / min, the volume concentration of SO2 to be 85% to 95%, and the de-alkalization temperature to be 450 °C to 750 °C.

3. The monitoring method according to claim 1, characterized in that: The size of the cut in S1 is not limited.

4. The monitoring method according to claim 1, characterized in that: The weak acid solution is oxalic acid, acetic acid or citric acid, or a combination thereof.

5. The monitoring method according to claim 1, wherein: The concentration of oxalic acid is 1 to 10 wt%, the concentration of acetic acid is 0 to 10 wt%, and the concentration of citric acid is 0 to 5 wt%.

6. The monitoring method according to any one of claims 1 to 5, characterized in that: The soaking time of the weak acid solution is at least 120 seconds, and the soaking temperature of the weak acid solution is at least 50 °C.

7. The monitoring method according to claim 1, characterized in that: The strong acid solution includes hydrochloric acid, sulfuric acid and hydrofluoric acid.

8. The monitoring method according to claim 7, wherein: Among them, the concentration of hydrofluoric acid is 1.0 to 2.5 wt%, the concentration of hydrochloric acid is 5% to 20% wt%, and the concentration of sulfuric acid is 5 - 10% wt%.

9. The monitoring method according to claim 7 or 8, characterized in that: The soaking time of the glass in the strong acid solution is at least 30 s, and the soaking temperature is at least 30 °C.

10. The monitoring method according to claim 1, wherein: The detection method of the roller marks and fogginess is as follows: First, irradiate the glass surface with a strong light with an illuminance of 6000 Lux at an angle of 20 °C. The human eye forms an angle of about 45 degrees with the glass plane, and the distance between the person and the sample is about 300 mm. The human eye observes the roller marks and fogginess on the glass surface qualitatively; use a vernier caliper to quantitatively measure the width of the marked roller marks; use a haze meter to test the foggy glass sample.

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