Method for preparing optical glass secondary strong liquid based on mixed acid effect

Abstract

The invention discloses a method for preparing optical glass secondary strong liquid based on a mixed acid effect, and belongs to the technical field of optical glass processing, in a mixed acid system, sulfuric acid is used as main acid to provide a strong corrosion environment and control the reaction rate, nitric acid is used for enhancing the oxidation capacity to eliminate surface impurities, hydrofluoric acid is used for accurately etching a glass microstructure to eliminate cracks, and the optical glass secondary strong liquid is prepared. Phosphoric acid improves the surface uniformity through a passivation effect. Oxalic acid and ammonium bifluoride further optimize the coordination ability of the acid liquor, the lattice damage is reduced while the glass thinning depth is enhanced, and the acid mist inhibitor effectively inhibits the dissipation of harmful gas by reducing the surface tension of the solution. The composite system breaks through the limitation of traditional single acid liquor treatment, not only can adapt to the differentiated requirements of different materials such as high-alumina-silica glass and lithium-alumina-silica glass on the corrosion rate, but also avoids the common stripe and flow mark defects in the traditional process, so that a compact and uniform strengthened layer is formed on the surface of the glass, and the mechanical strength and the light transmittance are synchronously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of optical glass processing, and in particular relates to a method for preparing optical glass second strong liquid based on mixed acid effect. Background Art

[0002] Glass strengthening technology plays an unparalleled cost advantage and mature solution in the thinning and strengthening of optical glass sheets. The erosion of acid can effectively reduce the microcracks generated in the glass sheet during the processing, thereby greatly improving the mechanical compressive strength of the glass sheet. Glass strengthening liquid, the full name of which is glass strengthening acid etching solution, is a chemical treatment agent used to enhance the surface hardness of glass and improve its heat shock resistance. Its main components usually include strong acids such as hydrofluoric acid, nitric acid, and sulfuric acid. Through acid etching, a compressive stress layer is formed on the glass surface, thereby improving the physical strength and chemical stability of the glass. The bending strength and impact resistance of glass treated with glass strengthening liquid can be significantly improved, and it is suitable for the manufacture of heat-resistant glassware, laboratory instruments, optical lenses and other products. During use, the concentration, temperature and processing time of the solution must be strictly controlled to ensure safety and effectiveness. At the same time, environmental protection regulations must be followed and the discharged waste liquid must be properly handled to reduce the impact on the environment.

[0003] However, traditional acid treatment processes mostly use a single acid or a simple mixed acid, which has defects such as low treatment efficiency, poor surface uniformity, and easy generation of streaks and flow marks. In addition, traditional acid has poor adaptability to certain special optical glass materials and is difficult to meet the precision processing requirements of high-precision optical components.

[0004] In order to solve the above problems, the present invention proposes a method for preparing a second strong solution of optical glass based on the principle of mixed acid effect. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing optical glass second strong liquid based on mixed acid effect in order to solve the above-mentioned problems.

[0006] The technical solution adopted by the present invention is as follows: a method for preparing a second strong solution of optical glass based on mixed acid effect, the method comprising the following steps:

[0007] S1: Weigh the raw materials first:

[0008] Sulfuric acid H2SO4: 15%~30%, nitric acid HNO3: 10%~20%, hydrofluoric acid HF: 10%~20%

[0009] Phosphoric acid H3PO 4:2% to 6%, oxalic acid: 1% to 3%, ammonium bifluoride 0.5% to 2%, acid mist inhibitor 0.1% to 0.2%, balance: pure water. (The acid mist inhibitor is sodium alkylbenzene sulfonate, which is used to reduce the surface tension of the liquid and inhibit the formation of acid mist); prepare an acid-resistant container and add pure water as the base solvent.

[0010] S2: Slowly add sulfuric acid into an acid-resistant container while continuously stirring to promote dissolution, and then let the solution stand to cool to room temperature.

[0011] S3: Add nitric acid, phosphoric acid and oxalic acid to the container in order, and stir thoroughly after adding each acid until the mixture is uniform.

[0012] S4: Slowly add hydrofluoric acid to the mixed acid solution and continue stirring to ensure that the acid solution system is fully integrated.

[0013] S5: Add ammonium bifluoride to the solution and stir until it is completely dissolved.

[0014] S6: Add the acid mist inhibitor sodium alkylbenzene sulfonate and stir until the surface tension of the solution is reduced and the formation of acid mist is effectively suppressed.

[0015] S7: Continue stirring the mixture until all components are completely dissolved to form a homogeneous and transparent second strong solution.

[0016] S8: Perform quality inspection on the prepared second strong solution to ensure that the acid ratio meets the preset range and no impurities remain.

[0017] S9: Store the second strong liquid in an acid-resistant container in a sealed state, away from light and high temperature environment, until it is used for optical glass strengthening treatment.

[0018] In a preferred embodiment, in step S1, a container resistant to strong acid corrosion needs to be selected before preparation. The material is preferably polytetrafluoroethylene or high-density polyethylene, and the volume needs to be adjusted according to the preparation amount. High-purity deionized water is added to the container as a basic solvent. The water resistivity needs to be ≥18MΩ·cm, and the water volume ratio is reserved according to the final ratio. The operating environment needs to be well ventilated and the temperature is controlled at 20-25°C to avoid impurities.

[0019] In a preferred embodiment, in step S2, industrial grade sulfuric acid with a concentration of ≥98% is slowly poured into pure water at a weight ratio of 15% to 30% of the total liquid volume. When adding, an acid-resistant dropper or funnel should be used to slowly inject along the inner wall of the container, and a mechanical stirrer should be used to continuously stir at a uniform speed, and the speed is controlled to be 200-300rpm to avoid local overheating or splashing. After the sulfuric acid is added, it is allowed to stand for 30 to 60 minutes, and the solution is allowed to cool naturally to room temperature to ensure the stability of the system.

[0020] In a preferred embodiment, in step S3, nitric acid, phosphoric acid and oxalic acid are added in order according to the ratio, with the amount of nitric acid accounting for 10% to 20%, the amount of phosphoric acid accounting for 2% to 6%, and the amount of oxalic acid accounting for 1% to 3%. Nitric acid is an industrial grade product with a concentration of 68% to 70%, the concentration of phosphoric acid is ≥85%, and oxalic acid is an analytical pure powder. Each acid needs to be stirred separately for 10 to 15 minutes after addition, the stirring speed is maintained at 150-200rpm, and the temperature is controlled below 30°C. Oxalic acid needs to be pre-dissolved in a small amount of pure water and then slowly poured to avoid solid residue.

[0021] In a preferred embodiment, in step S4, hydrofluoric acid is selected from electronic grade products with a concentration of ≥40%, and is slowly added three times at a weight ratio of 10% to 20%. Each addition is separated by 5 minutes, and the rotation speed is controlled to 100-150rpm by low-speed stirring to reduce volatilization, and the solution temperature is controlled to ≤35°C by an ice bath. After the addition is completed, stirring is continued for 20 minutes to allow the hydrofluoric acid to fully complex with other acid solutions to form a uniform mixed acid system.

[0022] In a preferred embodiment, in step S5, ammonium bifluoride is added to the solution twice, 70% of the amount is added for the first time, and the remaining 30% is added after 10 minutes, and the total amount of ammonium bifluoride accounts for 0.5% to 2%. The stirring speed is increased to 250rpm, and the dissolution time is ≥15 minutes to ensure that the ammonium bifluoride is completely dissociated and forms a stable coordination structure with the mixed acid. The transparency of the solution needs to be monitored during this process. If turbidity occurs, the stirring time needs to be extended to 30 minutes.

[0023] In a preferred embodiment, in step S6, the acid mist inhibitor is sodium alkylbenzene sulfonate, which is weighed at a ratio of 0.1% to 0.2% and then slowly sprinkled into the liquid surface. A magnetic stirrer is used to disperse at a low speed of 120 rpm for 15 minutes to uniformly adsorb the inhibitor on the surface of the solution and reduce the surface tension to ≤35 mN / m. During operation, the ventilation equipment needs to be turned off to reduce airflow interference and maintain the ambient humidity ≤60%.

[0024] In a preferred embodiment, in step S7, after all components are mixed, the mixture is switched to high-speed stirring mode, with the speed controlled at 300-400 rpm for 30 minutes, until the solution is uniform and transparent, with no visible particles or stratification. During this period, a constant temperature water bath is used to maintain the temperature at 35-40°C to accelerate dissolution and improve stability. The specific gravity of the final solution is controlled at 1.25-1.35 g / cm 3 , refractive index range is 1.38-1.42.

[0025] In a preferred embodiment, in step S8, the pH value is sampled and tested, which is required to be ≤1.0; the fluoride ion concentration is tested by ion chromatography, with a target value of 2.5-4.0 g / L; the acid mist suppression effect is observed for 24 hours, and no acid mist is precipitated. The suspended matter is filtered using a 0.22 μm filter membrane, and visual observation is performed to ensure that there is no crystallization or precipitation. After passing the test, each parameter is recorded, and unqualified batches need to adjust the ratio or re-stir according to the defect type.

[0026] In a preferred embodiment, in step S9, the prepared second strong liquid is transferred into a sealed acid-resistant container, which is made of black polyethylene or a storage tank lined with polytetrafluoroethylene, and stored in a light-proof environment at 10-30°C. The storage area needs to be away from heat sources and alkaline substances, and the lid should be opened regularly to check the liquid level. The shelf life does not exceed 3 months. When used, it needs to be stirred again for 5 minutes, and the pH value and specific gravity should be tested to see if they meet the process requirements.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] 1. In the present invention, the processing quality and process stability of optical glass are significantly improved through the effective combination of multi-acid synergy and functional additives. In the mixed acid system, sulfuric acid as the main acid provides a strong corrosive environment and controls the reaction rate, nitric acid enhances the oxidation ability to eliminate surface impurities, hydrofluoric acid accurately etches the glass microstructure to eliminate cracks, and phosphoric acid improves surface uniformity through passivation. Oxalic acid and ammonium bifluoride further optimize the acid coordination ability, while reducing lattice damage while enhancing the glass thinning depth, and the acid mist inhibitor effectively inhibits the escape of harmful gases by reducing the surface tension of the solution. This composite system breaks through the limitations of traditional single acid treatment, and can adapt to the differentiated corrosion rate requirements of different materials such as high-aluminum silicate glass and lithium aluminum silicate glass, and avoids the common streaks and flow marks defects in traditional processes, so that a dense and uniform strengthening layer is formed on the glass surface, and the mechanical strength and light transmittance are improved simultaneously.

[0029] 2. In the present invention, the activity of hydrofluoric acid is regulated by ammonium bifluoride, and the amount of hydrofluoric acid used is greatly reduced while ensuring the etching effect. Combined with the physical inhibition of acid mist by sodium alkylbenzene sulfonate, the emission of toxic volatiles and the risk of operating environment are significantly reduced. All raw materials are common industrial chemicals, and the preparation process does not require complex equipment or high temperature and high pressure conditions. Stable production can be achieved only through step-by-step mixing and temperature control, which greatly reduces equipment investment and energy consumption costs. The finished solution has excellent storage stability, can meet the needs of continuous production, reduce the pressure of waste liquid treatment, and is suitable for large-scale processing of high value-added products such as display glass and electronic backplane glass, with significant comprehensive benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the process principle of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] Embodiment 1:

[0033] Reference Figure 1 A method for preparing a second strong solution of optical glass based on mixed acid effect, the method comprising the following steps:

[0034] S1: Weigh the raw materials first:

[0035] Sulfuric acid H2SO4 25%, nitric acid HNO3 10%, hydrofluoric acid HF 10%, phosphoric acid H3PO4 5%, oxalic acid 3%, ammonium bifluoride 1.2%, acid mist inhibitor 0.1%, water 45.7%. (The acid mist inhibitor is sodium alkylbenzene sulfonate, which is used to reduce the surface tension of the liquid and inhibit the formation of acid mist); prepare an acid-resistant container and add pure water as the base solvent.

[0036] S2: Slowly add sulfuric acid into an acid-resistant container while continuously stirring to promote dissolution, and then let the solution stand to cool to room temperature.

[0037] S3: Add nitric acid, phosphoric acid and oxalic acid to the container in order, and stir thoroughly after adding each acid until the mixture is uniform.

[0038] S4: Slowly add hydrofluoric acid to the mixed acid solution and continue stirring to ensure that the acid solution system is fully integrated.

[0039] S5: Add ammonium bifluoride to the solution and stir until it is completely dissolved.

[0040] S6: Add the acid mist inhibitor sodium alkylbenzene sulfonate and stir until the surface tension of the solution is reduced and the formation of acid mist is effectively suppressed.

[0041] S7: Continue stirring the mixture until all components are completely dissolved to form a homogeneous and transparent second strong solution.

[0042] S8: Perform quality inspection on the prepared second strong solution to ensure that the acid ratio meets the preset range and no impurities remain.

[0043] S9: Store the second strong liquid in an acid-resistant container in a sealed state, away from light and high temperature environment, until it is used for optical glass strengthening treatment.

[0044] In step S1, a container resistant to strong acid corrosion must be selected before preparation. The recommended material is polytetrafluoroethylene or high-density polyethylene, and the volume needs to be adjusted according to the preparation amount. Add high-purity deionized water to the container as the basic solvent. The water resistivity must be ≥18MΩ·cm, and the water ratio must be reserved according to the final ratio. The operating environment must be well ventilated and the temperature must be controlled at 20-25℃ to avoid impurities.

[0045] In step S2, industrial grade sulfuric acid with a concentration of ≥98% is slowly poured into pure water at a weight ratio of 15% to 30% of the total liquid volume. When adding, an acid-resistant dropper or funnel should be used to slowly inject along the inner wall of the container, and a mechanical stirrer should be continuously stirred at a uniform speed, and the speed is controlled to 200-300rpm to avoid local overheating or splashing. After the sulfuric acid is added, it is allowed to stand for 30 to 60 minutes, and the solution is allowed to cool naturally to room temperature to ensure the stability of the system.

[0046] In step S3, nitric acid, phosphoric acid and oxalic acid are added in order according to the ratio, with nitric acid accounting for 10% to 20%, phosphoric acid accounting for 2% to 6%, and oxalic acid accounting for 1% to 3%. Nitric acid is an industrial-grade product with a concentration of 68% to 70%, phosphoric acid concentration is ≥85%, and oxalic acid is an analytical pure powder. Each acid needs to be stirred separately for 10 to 15 minutes after addition, the stirring speed is maintained at 150-200rpm, and the temperature is controlled below 30°C. Oxalic acid needs to be dissolved in a small amount of pure water in advance and then slowly poured to avoid solid residue.

[0047] In step S4, hydrofluoric acid is selected from electronic grade products with a concentration of ≥40%, and is slowly added three times at a weight ratio of 10% to 20%. Each addition is 5 minutes apart, and the rotation speed is controlled to 100-150rpm with low-speed stirring to reduce volatilization, and the solution temperature is controlled to ≤35°C with an ice bath. After the addition is completed, stirring is continued for 20 minutes to allow the hydrofluoric acid to fully complex with other acid solutions to form a uniform mixed acid system.

[0048] In step S5, ammonium bifluoride is added to the solution twice, 70% of the amount is added for the first time, and the remaining 30% is added after 10 minutes, and the total amount of ammonium bifluoride accounts for 0.5% to 2%. The stirring speed is increased to 250rpm, and the dissolution time is ≥15 minutes to ensure that the ammonium bifluoride is completely dissociated and forms a stable coordination structure with the mixed acid. The transparency of the solution needs to be monitored during this process. If turbidity occurs, the stirring time needs to be extended to 30 minutes.

[0049] In step S6, the acid mist inhibitor is sodium alkylbenzene sulfonate, which is weighed at a ratio of 0.1% to 0.2% and then slowly sprinkled into the liquid surface. A magnetic stirrer is used to disperse at a low speed of 120 rpm for 15 minutes to make the inhibitor uniformly adsorbed on the surface of the solution and reduce the surface tension to ≤35 mN / m. During operation, the ventilation equipment needs to be turned off to reduce air flow interference and maintain the ambient humidity ≤60%.

[0050] In step S7, after all components are mixed, switch to high-speed stirring mode, control the speed to 300-400rpm, and continue for 30 minutes until the solution is uniform and transparent, without visible particles or stratification. During this period, use a constant temperature water bath to maintain the temperature at 35-40°C to accelerate dissolution and improve stability. The final liquid specific gravity is controlled at 1.25-1.35g / cm 3 , refractive index range is 1.38-1.42.

[0051] In step S8, take a sample to test the pH value, which is required to be ≤1.0; use ion chromatography to test the fluoride ion concentration, with a target value of 2.5-4.0g / L; let it stand for 24 hours to observe the acid mist suppression effect, and no acid mist should be precipitated. Use a 0.22μm filter membrane to filter and detect suspended matter, and visually observe to ensure that there is no crystallization or precipitation. Record all parameters after passing the test, and unqualified batches need to adjust the ratio or re-stir according to the defect type.

[0052] In step S9, the prepared second strong liquid is transferred into a sealed acid-resistant container made of black polyethylene or a storage tank lined with polytetrafluoroethylene, and stored in a light-proof environment at 10-30°C. The storage area needs to be away from heat sources and alkaline substances, and the lid should be opened regularly to check the liquid level. The shelf life is no more than 3 months. When using, it needs to be stirred again for 5 minutes, and the pH value and specific gravity should be tested to see if they meet the process requirements.

[0053] Embodiment 2:

[0054] Reference Figure 1 A method for preparing a second strong solution of optical glass based on mixed acid effect, the method comprising the following steps:

[0055] S1: Weigh the raw materials first:

[0056] Sulfuric acid H2SO4 22%, nitric acid HNO3 12%, hydrofluoric acid HF 12%, phosphoric acid H3PO4 4%, oxalic acid 2.5%, ammonium bifluoride 1%, acid mist inhibitor 0.2%, water 46.3%. (Acid mist inhibitor is sodium alkylbenzene sulfonate, used to reduce liquid surface tension and inhibit acid mist formation); prepare an acid-resistant container and add pure water as the base solvent.

[0057] S2: Slowly add sulfuric acid into an acid-resistant container while continuously stirring to promote dissolution, and then let the solution stand to cool to room temperature.

[0058] S3: Add nitric acid, phosphoric acid and oxalic acid to the container in order, and stir thoroughly after adding each acid until the mixture is uniform.

[0059] S4: Slowly add hydrofluoric acid to the mixed acid solution and continue stirring to ensure that the acid solution system is fully integrated.

[0060] S5: Add ammonium bifluoride to the solution and stir until it is completely dissolved.

[0061] S6: Add the acid mist inhibitor sodium alkylbenzene sulfonate and stir until the surface tension of the solution is reduced and the formation of acid mist is effectively suppressed.

[0062] S7: Continue stirring the mixture until all components are completely dissolved to form a homogeneous and transparent second strong solution.

[0063] S8: Perform quality inspection on the prepared second strong solution to ensure that the acid ratio meets the preset range and no impurities remain.

[0064] S9: Store the second strong liquid in an acid-resistant container in a sealed state, away from light and high temperature environment, until it is used for optical glass strengthening treatment.

[0065] In step S1, a container resistant to strong acid corrosion must be selected before preparation. The recommended material is polytetrafluoroethylene or high-density polyethylene, and the volume needs to be adjusted according to the preparation amount. Add high-purity deionized water to the container as the basic solvent. The water resistivity must be ≥18MΩ·cm, and the water ratio must be reserved according to the final ratio. The operating environment must be well ventilated and the temperature must be controlled at 20-25℃ to avoid impurities.

[0066] In step S2, industrial grade sulfuric acid with a concentration of ≥98% is slowly poured into pure water at a weight ratio of 15% to 30% of the total liquid volume. When adding, an acid-resistant dropper or funnel should be used to slowly inject along the inner wall of the container, and a mechanical stirrer should be continuously stirred at a uniform speed, and the speed is controlled to 200-300rpm to avoid local overheating or splashing. After the sulfuric acid is added, it is allowed to stand for 30 to 60 minutes, and the solution is allowed to cool naturally to room temperature to ensure the stability of the system.

[0067] In step S3, nitric acid, phosphoric acid and oxalic acid are added in order according to the ratio, with nitric acid accounting for 10% to 20%, phosphoric acid accounting for 2% to 6%, and oxalic acid accounting for 1% to 3%. Nitric acid is an industrial-grade product with a concentration of 68% to 70%, phosphoric acid concentration is ≥85%, and oxalic acid is an analytical pure powder. Each acid needs to be stirred separately for 10 to 15 minutes after addition, the stirring speed is maintained at 150-200rpm, and the temperature is controlled below 30°C. Oxalic acid needs to be dissolved in a small amount of pure water in advance and then slowly poured to avoid solid residue.

[0068] In step S4, hydrofluoric acid is selected from electronic grade products with a concentration of ≥40%, and is slowly added three times at a weight ratio of 10% to 20%. Each addition is 5 minutes apart, and the rotation speed is controlled to 100-150rpm with low-speed stirring to reduce volatilization, and the solution temperature is controlled to ≤35°C with an ice bath. After the addition is completed, stirring is continued for 20 minutes to allow the hydrofluoric acid to fully complex with other acid solutions to form a uniform mixed acid system.

[0069] In step S5, ammonium bifluoride is added to the solution twice, 70% of the amount is added for the first time, and the remaining 30% is added after 10 minutes, and the total amount of ammonium bifluoride accounts for 0.5% to 2%. The stirring speed is increased to 250rpm, and the dissolution time is ≥15 minutes to ensure that the ammonium bifluoride is completely dissociated and forms a stable coordination structure with the mixed acid. The transparency of the solution needs to be monitored during this process. If turbidity occurs, the stirring time needs to be extended to 30 minutes.

[0070] In step S6, the acid mist inhibitor is sodium alkylbenzene sulfonate, which is weighed at a ratio of 0.1% to 0.2% and then slowly sprinkled into the liquid surface. A magnetic stirrer is used to disperse at a low speed of 120 rpm for 15 minutes to make the inhibitor uniformly adsorbed on the surface of the solution and reduce the surface tension to ≤35 mN / m. During operation, the ventilation equipment needs to be turned off to reduce air flow interference and maintain the ambient humidity ≤60%.

[0071] In step S7, after all components are mixed, switch to high-speed stirring mode, control the speed to 300-400rpm, and continue for 30 minutes until the solution is uniform and transparent, without visible particles or stratification. During this period, use a constant temperature water bath to maintain the temperature at 35-40°C to accelerate dissolution and improve stability. The final liquid specific gravity is controlled at 1.25-1.35g / cm 3 , refractive index range is 1.38-1.42.

[0072] In step S8, take a sample to test the pH value, which is required to be ≤1.0; use ion chromatography to test the fluoride ion concentration, with a target value of 2.5-4.0g / L; let it stand for 24 hours to observe the acid mist suppression effect, and no acid mist should be precipitated. Use a 0.22μm filter membrane to filter and detect suspended matter, and visually observe to ensure that there is no crystallization or precipitation. Record all parameters after passing the test, and unqualified batches need to adjust the ratio or re-stir according to the defect type.

[0073] In step S9, the prepared second strong liquid is transferred into a sealed acid-resistant container made of black polyethylene or a storage tank lined with polytetrafluoroethylene, and stored in a light-proof environment at 10-30°C. The storage area needs to be away from heat sources and alkaline substances, and the lid should be opened regularly to check the liquid level. The shelf life is no more than 3 months. When using, it needs to be stirred again for 5 minutes, and the pH value and specific gravity should be tested to see if they meet the process requirements.

[0074] Embodiment three:

[0075] Reference Figure 1 A method for preparing a second strong solution of optical glass based on mixed acid effect, the method comprising the following steps:

[0076] S1: Weigh the raw materials first:

[0077] Sulfuric acid H2SO4 20%, nitric acid HNO3 12%, hydrofluoric acid HF 15%, phosphoric acid H3PO4 3%, oxalic acid 2%, ammonium bifluoride 1.6%, acid mist inhibitor 0.2%, water 46.2%. (Acid mist inhibitor is sodium alkylbenzene sulfonate, used to reduce liquid surface tension and inhibit acid mist formation); prepare an acid-resistant container and add pure water as the base solvent.

[0078] S2: Slowly add sulfuric acid into an acid-resistant container while continuously stirring to promote dissolution, and then let the solution stand to cool to room temperature.

[0079] S3: Add nitric acid, phosphoric acid and oxalic acid to the container in order, and stir thoroughly after adding each acid until the mixture is uniform.

[0080] S4: Slowly add hydrofluoric acid to the mixed acid solution and continue stirring to ensure that the acid solution system is fully integrated.

[0081] S5: Add ammonium bifluoride to the solution and stir until it is completely dissolved.

[0082] S6: Add the acid mist inhibitor sodium alkylbenzene sulfonate and stir until the surface tension of the solution is reduced and the formation of acid mist is effectively suppressed.

[0083] S7: Continue stirring the mixture until all components are completely dissolved to form a homogeneous and transparent second strong solution.

[0084] S8: Perform quality inspection on the prepared second strong solution to ensure that the acid ratio meets the preset range and no impurities remain.

[0085] S9: Store the second strong liquid in an acid-resistant container in a sealed state, away from light and high temperature environment, until it is used for optical glass strengthening treatment.

[0086] In step S1, a container resistant to strong acid corrosion must be selected before preparation. The recommended material is polytetrafluoroethylene or high-density polyethylene, and the volume needs to be adjusted according to the preparation amount. Add high-purity deionized water to the container as the basic solvent. The water resistivity must be ≥18MΩ·cm, and the water ratio must be reserved according to the final ratio. The operating environment must be well ventilated and the temperature must be controlled at 20-25℃ to avoid impurities.

[0087] In step S2, industrial grade sulfuric acid with a concentration of ≥98% is slowly poured into pure water at a weight ratio of 15% to 30% of the total liquid volume. When adding, an acid-resistant dropper or funnel should be used to slowly inject along the inner wall of the container, and a mechanical stirrer should be continuously stirred at a uniform speed, and the speed is controlled to 200-300rpm to avoid local overheating or splashing. After the sulfuric acid is added, it is allowed to stand for 30 to 60 minutes, and the solution is allowed to cool naturally to room temperature to ensure the stability of the system.

[0088] In step S3, nitric acid, phosphoric acid and oxalic acid are added in order according to the ratio, with nitric acid accounting for 10% to 20%, phosphoric acid accounting for 2% to 6%, and oxalic acid accounting for 1% to 3%. Nitric acid is an industrial-grade product with a concentration of 68% to 70%, phosphoric acid concentration is ≥85%, and oxalic acid is an analytical pure powder. Each acid needs to be stirred separately for 10 to 15 minutes after addition, the stirring speed is maintained at 150-200rpm, and the temperature is controlled below 30°C. Oxalic acid needs to be dissolved in a small amount of pure water in advance and then slowly poured to avoid solid residue.

[0089] In step S4, hydrofluoric acid is selected from electronic grade products with a concentration of ≥40%, and is slowly added three times at a weight ratio of 10% to 20%. Each addition is 5 minutes apart, and the rotation speed is controlled to 100-150rpm with low-speed stirring to reduce volatilization, and the solution temperature is controlled to ≤35°C with an ice bath. After the addition is completed, stirring is continued for 20 minutes to allow the hydrofluoric acid to fully complex with other acid solutions to form a uniform mixed acid system.

[0090] In step S5, ammonium bifluoride is added to the solution twice, 70% of the amount is added for the first time, and the remaining 30% is added after 10 minutes, and the total amount of ammonium bifluoride accounts for 0.5% to 2%. The stirring speed is increased to 250rpm, and the dissolution time is ≥15 minutes to ensure that the ammonium bifluoride is completely dissociated and forms a stable coordination structure with the mixed acid. The transparency of the solution needs to be monitored during this process. If turbidity occurs, the stirring time needs to be extended to 30 minutes.

[0091] In step S6, the acid mist inhibitor is sodium alkylbenzene sulfonate, which is weighed at a ratio of 0.1% to 0.2% and then slowly sprinkled into the liquid surface. A magnetic stirrer is used to disperse at a low speed of 120 rpm for 15 minutes to make the inhibitor uniformly adsorbed on the surface of the solution and reduce the surface tension to ≤35 mN / m. During operation, the ventilation equipment needs to be turned off to reduce air flow interference and maintain the ambient humidity ≤60%.

[0092] In step S7, after all components are mixed, switch to high-speed stirring mode, control the speed to 300-400rpm, and continue for 30 minutes until the solution is uniform and transparent, without visible particles or stratification. During this period, use a constant temperature water bath to maintain the temperature at 35-40°C to accelerate dissolution and improve stability. The final liquid specific gravity is controlled at 1.25-1.35g / cm 3 , refractive index range is 1.38-1.42.

[0093] In step S8, take a sample to test the pH value, which is required to be ≤1.0; use ion chromatography to test the fluoride ion concentration, with a target value of 2.5-4.0g / L; let it stand for 24 hours to observe the acid mist suppression effect, and no acid mist should be precipitated. Use a 0.22μm filter membrane to filter and detect suspended matter, and visually observe to ensure that there is no crystallization or precipitation. Record all parameters after passing the test, and unqualified batches need to adjust the ratio or re-stir according to the defect type.

[0094] In step S9, the prepared second strong liquid is transferred into a sealed acid-resistant container made of black polyethylene or a storage tank lined with polytetrafluoroethylene, and stored in a light-proof environment at 10-30°C. The storage area needs to be away from heat sources and alkaline substances, and the lid should be opened regularly to check the liquid level. The shelf life is no more than 3 months. When using, it needs to be stirred again for 5 minutes, and the pH value and specific gravity should be tested to see if they meet the process requirements.

[0095] From the above we can know:

[0096] In the present invention, the processing quality and process stability of optical glass are significantly improved through the effective combination of multi-acid synergy and functional additives. In the mixed acid system, sulfuric acid as the main acid provides a strong corrosive environment and controls the reaction rate, nitric acid enhances the oxidation ability to eliminate surface impurities, hydrofluoric acid accurately etches the glass microstructure to eliminate cracks, and phosphoric acid improves surface uniformity through passivation. Oxalic acid and ammonium bifluoride further optimize the acid coordination ability, while reducing lattice damage while enhancing the glass thinning depth, and the acid mist inhibitor effectively inhibits the escape of harmful gases by reducing the surface tension of the solution. This composite system breaks through the limitations of traditional single acid treatment, and can adapt to the differentiated requirements of corrosion rates of different materials such as high-aluminum-silicon glass and lithium-aluminum-silicon glass, and avoids the common streaks and flow marks defects in traditional processes, so that a dense and uniform strengthening layer is formed on the glass surface, and the mechanical strength and light transmittance are improved simultaneously.

[0097] In the present invention, the activity of hydrofluoric acid is regulated by ammonium bifluoride, the amount of hydrofluoric acid is greatly reduced under the premise of ensuring the etching effect, and the physical inhibition of acid mist by sodium alkylbenzene sulfonate is combined to significantly reduce the emission of toxic volatiles and the risk of operating environment. All raw materials are common industrial chemicals, and the preparation process does not require complex equipment or high temperature and high pressure conditions. Stable production can be achieved only through step-by-step mixing and temperature control, which greatly reduces equipment investment and energy consumption costs. The finished solution has excellent storage stability, can meet the needs of continuous production, reduce the pressure of waste liquid treatment, is suitable for large-scale processing of high value-added products such as display glass and electronic backplane glass, and has significant comprehensive benefits.

[0098] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0099] The above description enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a second strong solution for optical glass based on mixed acid effect, characterized in that: The method comprises the following steps: S1: Weigh the raw materials first: Sulfuric acid H2SO4: 15%~30%, nitric acid HNO3: 10%~20%, hydrofluoric acid HF: 10%~20% Phosphoric acid H3PO4: 2% to 6%, oxalic acid: 1% to 3%, ammonium bifluoride 0.5% to 2%, acid mist inhibitor 0.1% to 0.2%, balance: pure water; (the acid mist inhibitor is sodium alkylbenzene sulfonate, which is used to reduce the surface tension of the liquid and inhibit the formation of acid mist); prepare an acid-resistant container and add pure water as the base solvent; S2: Slowly add sulfuric acid into an acid-resistant container while continuously stirring to promote dissolution, and then let the solution stand to cool to room temperature; S3: Add nitric acid, phosphoric acid and oxalic acid to the container in order, and stir thoroughly after adding each acid until the mixture is uniformly mixed; S4: slowly add hydrofluoric acid to the mixed acid solution, and continue stirring to ensure that the acid solution system is fully integrated; S5: adding ammonium bifluoride to the solution and stirring until it is completely dissolved; S6: adding sodium alkylbenzene sulfonate, an acid mist inhibitor, and stirring until the surface tension of the solution is reduced and the formation of acid mist is effectively suppressed; S7: Continue stirring the mixture until all components are completely dissolved to form a homogeneous and transparent second strong solution; S8: Perform quality inspection on the prepared second strong solution to ensure that the acid solution ratio meets the preset range and no impurities remain; S9: Store the second strong liquid in an acid-resistant container in a sealed state, away from light and high temperature environment, until it is used for optical glass strengthening treatment.

2. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In the step S1, a container resistant to strong acid corrosion needs to be selected before preparation, and polytetrafluoroethylene or high-density polyethylene is recommended as the material, and the volume needs to be adjusted according to the preparation amount; high-purity deionized water is added to the container as a basic solvent, and the water quality resistivity needs to be ≥18MΩ·cm, and the water ratio is reserved according to the final ratio; the operating environment needs to be well ventilated and the temperature is controlled at 20-25°C to avoid impurities.

3. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In the step S2, industrial grade sulfuric acid with a concentration of ≥98% is slowly poured into pure water at a weight ratio of 15% to 30% of the total liquid volume; when adding, an acid-resistant dropper or funnel is used to slowly inject along the inner wall of the container, and a mechanical stirrer is continuously stirred at a uniform speed, and the speed is controlled to be 200-300rpm to avoid local overheating or splashing; after the sulfuric acid is added, it is allowed to stand for 30 to 60 minutes, and the solution is allowed to cool naturally to room temperature to ensure the stability of the system.

4. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In the step S3, nitric acid, phosphoric acid and oxalic acid are added in sequence according to the proportion, with the amount of nitric acid accounting for 10% to 20%, the amount of phosphoric acid accounting for 2% to 6%, and the amount of oxalic acid accounting for 1% to 3%; nitric acid is an industrial-grade product with a concentration of 68% to 70%, the concentration of phosphoric acid is ≥85%, and oxalic acid is an analytical pure powder; each acid needs to be stirred separately for 10 to 15 minutes after being added, the stirring speed is maintained at 150-200 rpm, and the temperature is controlled below 30°C; oxalic acid needs to be pre-dissolved in a small amount of pure water and then slowly poured to avoid solid residue.

5. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In the step S4, hydrofluoric acid is selected from electronic grade products with a concentration of ≥40%, and is slowly added three times at a weight ratio of 10% to 20%; each addition is separated by 5 minutes, and the rotation speed is controlled to 100-150rpm by low speed stirring to reduce volatilization, and the solution temperature is controlled to ≤35°C by an ice bath; after the addition is completed, stirring is continued for 20 minutes to allow the hydrofluoric acid to fully complex with other acid solutions to form a uniform mixed acid system.

6. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In the step S5, ammonium bifluoride is added to the solution twice, 70% of the amount is added for the first time, and the remaining 30% is added after 10 minutes, and the total amount of ammonium bifluoride accounts for 0.5% to 2%; the stirring speed is increased to 250rpm, and the dissolution time is ≥15 minutes to ensure that the ammonium bifluoride is completely dissociated and forms a stable coordination structure with the mixed acid; the transparency of the solution needs to be monitored during this process, and if turbidity occurs, the stirring time needs to be extended to 30 minutes.

7. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In the step S6, the acid mist inhibitor is sodium alkylbenzene sulfonate, which is weighed at a ratio of 0.1% to 0.2% and then slowly sprinkled into the liquid surface; a magnetic stirrer is used to disperse at a low speed of 120 rpm for 15 minutes to allow the inhibitor to be uniformly adsorbed on the surface of the solution and reduce the surface tension to ≤35 mN / m; during operation, the ventilation equipment needs to be turned off to reduce air flow interference and maintain the ambient humidity ≤60%.

8. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In step S7, after all components are mixed, the high-speed stirring mode is switched to control the speed to 300-400 rpm for 30 minutes until the solution is uniform and transparent without visible particles or stratification; during this period, a constant temperature water bath is used to maintain the temperature at 35-40°C to accelerate dissolution and improve stability; the final liquid specific gravity is controlled at 1.25-1.35 g / cm 3 , refractive index range is 1.38-1.

42.

9. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In the step S8, sampling is performed to detect the pH value, which is required to be ≤1.0; the fluoride ion concentration is detected by ion chromatography, with a target value of 2.5-4.0 g / L; the acid mist suppression effect is observed for 24 hours, and no acid mist is precipitated; and suspended matter is detected by filtering with a 0.22 μm filter membrane.

10. The method for preparing optical glass second strong liquid based on mixed acid effect as claimed in claim 1, characterized in that: In step S9, the prepared second strong liquid is transferred into a sealed acid-resistant container, which is made of black polyethylene or a storage tank lined with polytetrafluoroethylene, and is stored in a light-proof environment at 10-30°C. The storage area needs to be away from heat sources and alkaline substances, and the lid should be opened regularly to check the liquid level. The shelf life does not exceed 3 months. When used, it needs to be stirred again for 5 minutes, and the pH value and specific gravity should be tested to see if they meet the process requirements.

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