Method for comprehensively utilizing fluorine-containing gypsum in glass thinning industry

Abstract

The invention discloses a method for comprehensively utilizing fluorine-containing gypsum in the glass thinning industry. The method comprises eight procedures of low-temperature molten salt conversion, wet grinding leaching, wet grinding alkali conversion, neutralization, sodium fluoride evaporative crystallization, acid leaching, magnesium nitrate regeneration and magnesium nitrate evaporative crystallization. Compared with the prior art, the method for comprehensively utilizing the fluorine-containing gypsum in the glass thinning industry has the advantages that fluoride in the fluorine-containing gypsum is efficiently converted into sodium fluoride, and sustainable utilization of resources is realized.

Description

Technical Field

[0001] The invention relates to the field of solid waste recycling and reuse in the glass thinning industry, and in particular to a method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry. Background Art

[0002] my country's optoelectronics industry is developing rapidly, and the trend of thinning glass display screens is becoming more and more obvious. During the glass thinning process, the etching solution, whose main component is hydrofluoric acid, will react with the silicon dioxide in the glass to generate a large amount of waste liquid containing fluorosilicic acid. The enrichment of fluorosilicic acid will increase the viscosity of the etching solution and reduce the etching efficiency. When the concentration of fluorosilicic acid reaches a certain level, the waste liquid must be discharged.

[0003] At present, the waste liquid of glass thinning and etching is mainly treated by lime neutralization method, thereby producing a large amount of fluorinated gypsum, the main components of which are calcium fluoride and calcium sulfate. However, the existing treatment methods are usually simply stored or landfilled after neutralization, which not only causes a great waste of resources, but also has a serious negative impact on the environment. A patent discloses a method for preparing an aluminate solution by high-temperature roasting, alkali leaching, adsorption and elution of fluorinated gypsum, aluminum electrolyte and ammonium carbonate. The method requires roasting at a high temperature of 750°C to 900°C, with extremely high energy consumption, and sulfur dioxide waste gas will be generated during the roasting process. There is also a patent that discloses a method for preparing ultrafine light calcium carbonate and ammonium sulfate by reacting fluorinated gypsum, ammonia water, surfactant and ammonium bicarbonate in a solution. Although this method can convert fluorinated gypsum into products with certain economic value, its economic benefits are not high and the conversion utilization rate of fluorinated gypsum is limited. In addition, a patent discloses a method for the comprehensive utilization of fluorine-containing gypsum and fluorosilicic acid, a by-product of phosphate fertilizer. This method obtains calcium fluoride and agricultural ammonium sulfate products through process steps such as ammoniation of fluorosilicic acid, filtration, and evaporation crystallization. However, calcium fluoride is highly stable and difficult to reuse.

[0004] Therefore, how to provide a method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry so that the fluorine-containing gypsum in the glass thinning industry can be treated by this method to achieve efficient conversion of fluoride in the fluorine-containing gypsum into sodium fluoride and realize sustainable utilization of resources is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of the problems existing in the prior art, the technical problem to be solved by the present invention is to provide a method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry, so that after the fluorine-containing gypsum in the glass thinning industry is treated by this method, the fluoride in the fluorine-containing gypsum can be effectively converted into sodium fluoride, thereby realizing the sustainable utilization of resources.

[0006] To achieve the above-mentioned purpose, the present invention provides a method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry, and the method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry comprises: S1, low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasting slag; S2, wet grinding and leaching: wet grinding and leaching the roasting slag obtained in S1, solid-liquid separation, and wet grinding leaching slag and wet grinding leaching liquid; S3, wet grinding alkali conversion: adding sodium hydroxide to the wet grinding leaching slag obtained in S2 for wet grinding alkali conversion, solid-liquid separation, and alkali conversion slag and alkali conversion liquid; S4, neutralization: adding sodium hydroxide to the wet grinding leaching slag obtained in S3 for wet grinding alkali conversion, solid-liquid separation, and alkali conversion slag and alkali conversion liquid. The obtained alkali-converted liquid is neutralized with hydrofluoric acid to obtain a neutralized liquid; S5, sodium fluoride evaporation crystallization: the neutralized liquid obtained in S4 is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; S6, acid leaching: the alkali-converted slag obtained in S3 is acid-leached with an aqueous sulfuric acid solution, and the solid-liquid separation is performed to obtain acid leaching slag and acid leaching liquid; S7, magnesium nitrate regeneration: calcium nitrate is added to the acid leaching liquid obtained in S6 to react, and the solid-liquid separation is performed to obtain regenerated slag and regenerated liquid; S8, magnesium nitrate evaporation crystallization: the regenerated liquid obtained in S7 is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor.

[0007] In the first aspect, in S1, the amount of magnesium nitrate hexahydrate added is 1.5 to 2 times the theoretical reaction molar amount of fluoride in the fluoride-containing gypsum, the calcination time is 2 to 8 hours, and the calcination temperature is 100 to 600°C.

[0008] In the first aspect, in S2, the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 6-10, the liquid-to-solid ratio of the wet milling leaching is 4-10 mL / g, the ball milling time of the wet milling leaching is 0.5-1.5 hours, and the ball milling speed of the wet milling leaching is 100-200 rpm.

[0009] In the first aspect, in S3, the amount of sodium hydroxide added is 1 to 2 times the theoretical reaction molar amount of fluoride in the wet-milled leaching residue, the ball-to-material ratio of the wet-milling alkali-milling is 8 to 12, the liquid-to-solid ratio of the wet-milling alkali-milling is 1 to 4 mL / g, the ball-milling time of the wet-milling alkali-milling is 2 to 4 hours, and the ball-milling speed of the wet-milling alkali-milling is 400 to 600 rpm.

[0010] In the first aspect, in S5, the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process in S3.

[0011] In the first aspect, in S6, the molar amount of the aqueous sulfuric acid solution is 1.5 to 2 times the theoretical reaction molar amount of calcium and magnesium in the alkali-converted slag, the acid leaching time is 0.2 to 2 hours, the acid leaching temperature is 25 to 50°C, and the liquid-to-solid ratio of the aqueous sulfuric acid solution to the alkali-converted slag is 8 to 14 mL / g.

[0012] In the first aspect, in S6, the acid leaching residue is used as a building material.

[0013] In the first aspect, in S7, the amount of calcium nitrate added is 1 to 2 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 0.5 to 2 hours, the reaction temperature is 25 to 60°C, and the liquid-to-solid ratio of the acid leaching solution to the calcium nitrate is 6 to 14 mL / g.

[0014] In the first aspect, in S7, the recycled slag is used as a building material.

[0015] In the first aspect, in S8, the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process in S1; and the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process in S7.

[0016] Beneficial effects:

[0017] The method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry of the present invention is used to process the fluorine-containing gypsum produced in the glass thinning industry and realize the recovery of fluoride ions and the efficient conversion of fluoride in the fluorine-containing gypsum into sodium fluoride, thereby realizing the recycling of resources. The fluorine-containing gypsum produced in the glass thinning industry mainly contains calcium sulfate and calcium fluoride. The present invention adds magnesium nitrate hexahydrate to the fluorine-containing gypsum for low-temperature molten salt conversion, mainly the reaction of calcium fluoride and magnesium nitrate hexahydrate to obtain roasted slag, and the main components of the roasted slag are calcium nitrate, magnesium fluoride and magnesium sulfate; then water is added to the roasted slag for wet grinding to obtain wet-milled leaching slag and wet-milled leaching liquid, respectively. The main components of the wet-milled leaching slag are magnesium fluoride and calcium sulfate, and the main component of the wet-milled leaching liquid is calcium nitrate. The effluent is directly used in the subsequent magnesium nitrate regeneration process to achieve effective utilization of resources; sodium hydroxide is added to the wet-grinding leaching residue for wet-grinding alkali conversion to obtain alkali conversion residue and alkali conversion liquid, the main components of the alkali conversion residue are magnesium hydroxide and calcium sulfate, and the alkali conversion liquid mainly contains fluoride ions, sodium ions and hydroxide ions. The alkali conversion liquid is neutralized with hydrofluoric acid and then evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor, and the obtained sodium fluoride crystallization mother liquor is reused in the grinding alkali conversion process to further recover Fluoride ions are extracted and sodium fluoride is extracted; the obtained alkali-converted slag is acid-leached with an aqueous sulfuric acid solution to obtain acid-leached slag and an acid-leached liquid, the main component of the acid-leached slag is calcium sulfate, which can be used as a building material, and the acid-leached liquid mainly contains sulfate ions and magnesium ions, calcium nitrate is added to the acid-leached slag to obtain regenerated slag and a regenerated liquid, the regenerated slag is mainly calcium sulfate, which can be used as a building material, and the regenerated liquid mainly contains nitrate ions and magnesium ions, and magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor are obtained by evaporation and crystallization, and the magnesium nitrate crystallization mother liquor is reused in the magnesium nitrate regeneration process, and magnesium ions are continuously extracted to obtain magnesium nitrate hexahydrate, so as to further recover magnesium ions and extract magnesium nitrate, and the obtained magnesium nitrate hexahydrate is reused in the low-temperature molten salt conversion process, thereby realizing the recycling of resources; in summary, the method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry of the present invention not only realizes the efficient conversion of fluoride in fluorine-containing gypsum to sodium fluoride, but also the obtained magnesium nitrate hexahydrate is reused in the low-temperature lava conversion process, thereby realizing the sustainable utilization of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is a process diagram of a method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0021] Embodiment 1

[0022] like Figure 1 As shown, the present embodiment 1 provides a method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry, and the method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry includes: S1, low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasting slag; S2, wet grinding and leaching: wet grinding and leaching the roasting slag obtained in S1, solid-liquid separation, to obtain wet grinding leaching slag and wet grinding leaching liquid; S3, wet grinding alkali conversion: adding sodium hydroxide to the wet grinding leaching slag obtained in S2 for wet grinding alkali conversion, solid-liquid separation, to obtain alkali conversion slag and alkali conversion liquid; S4, neutralization: the slag obtained in S3 is The alkali-converted liquid obtained is neutralized with hydrofluoric acid to obtain a neutralized liquid; S5, sodium fluoride evaporation crystallization: the neutralized liquid obtained in S4 is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; S6, acid leaching: the alkali-converted slag obtained in S3 is acid-leached with an aqueous sulfuric acid solution, and the solid-liquid separation is performed to obtain acid leaching slag and acid leaching liquid; S7, magnesium nitrate regeneration: calcium nitrate is added to the acid leaching liquid obtained in S6 to react, and the solid-liquid separation is performed to obtain regenerated slag and regenerated liquid; S8, magnesium nitrate evaporation crystallization: the regenerated liquid obtained in S7 is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor.

[0023] The method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry of the present invention is used to process the fluorine-containing gypsum produced in the glass thinning industry and realize the recovery of fluoride ions and the efficient conversion of fluoride in the fluorine-containing gypsum into sodium fluoride, thereby realizing the recycling of resources. The fluorine-containing gypsum produced in the glass thinning industry mainly contains calcium sulfate and calcium fluoride. The present invention adds magnesium nitrate hexahydrate to the fluorine-containing gypsum for low-temperature molten salt conversion, mainly the reaction of calcium fluoride and magnesium nitrate hexahydrate to obtain roasted slag, and the main components of the roasted slag are calcium nitrate, magnesium fluoride and magnesium sulfate; then water is added to the roasted slag for wet grinding to obtain wet-milled leaching slag and wet-milled leaching liquid, respectively. The main components of the wet-milled leaching slag are magnesium fluoride and calcium sulfate, and the main component of the wet-milled leaching liquid is calcium nitrate. The effluent is directly used in the subsequent magnesium nitrate regeneration process to achieve effective utilization of resources; sodium hydroxide is added to the wet-grinding leaching residue for wet-grinding alkali conversion to obtain alkali conversion residue and alkali conversion liquid, the main components of the alkali conversion residue are magnesium hydroxide and calcium sulfate, and the alkali conversion liquid mainly contains fluoride ions, sodium ions and hydroxide ions. The alkali conversion liquid is neutralized with hydrofluoric acid and then evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor, and the obtained sodium fluoride crystallization mother liquor is reused in the grinding alkali conversion process to further recover Fluoride ions are extracted and sodium fluoride is extracted; the obtained alkali-converted slag is acid-leached with an aqueous sulfuric acid solution to obtain acid-leached slag and an acid-leached liquid, the main component of the acid-leached slag is calcium sulfate, which can be used as a building material, and the acid-leached liquid mainly contains sulfate ions and magnesium ions, calcium nitrate is added to the acid-leached slag to obtain regenerated slag and a regenerated liquid, the regenerated slag is mainly calcium sulfate, which can be used as a building material, and the regenerated liquid mainly contains nitrate ions and magnesium ions, and magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor are obtained by evaporation and crystallization, and the magnesium nitrate crystallization mother liquor is reused in the magnesium nitrate regeneration process, and magnesium ions are continuously extracted to obtain magnesium nitrate hexahydrate, so as to further recover magnesium ions and extract magnesium nitrate, and the obtained magnesium nitrate hexahydrate is reused in the low-temperature molten salt conversion process, thereby realizing the recycling of resources; in summary, the method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry of the present invention not only realizes the efficient conversion of fluoride in fluorine-containing gypsum to sodium fluoride, but also the obtained magnesium nitrate hexahydrate is reused in the low-temperature lava conversion process, thereby realizing the sustainable utilization of resources.

[0024] In some possible implementations, in S1, the amount of magnesium nitrate hexahydrate added is 1.5 to 2 times the theoretical reaction molar amount of fluoride in the fluoride-containing gypsum, the calcination time is 2 to 8 hours, and the calcination temperature is 100 to 600°C.

[0025] Specifically, magnesium nitrate hexahydrate reacts with calcium fluoride in fluoride-containing gypsum to obtain calcium nitrate and magnesium fluoride.

[0026] In some possible implementations, in S2, the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 6-10, the liquid-to-solid ratio of the wet milling leaching is 4-10 mL / g, the ball milling time of the wet milling leaching is 0.5-1.5 hours, and the ball milling speed of the wet milling leaching is 100-200 rpm.

[0027] Specifically, the roasted slag mainly contains calcium nitrate, magnesium fluoride and calcium sulfate. After wet grinding and leaching, the magnesium fluoride precipitate, calcium sulfate precipitate and calcium nitrate are separated for subsequent treatment.

[0028] In some possible implementations, in S3, the amount of sodium hydroxide added is 1 to 2 times the theoretical reaction molar amount of fluoride in the wet-milled leaching residue, the ball-to-material ratio of the wet-milling alkali-turn is 8 to 12, the liquid-to-solid ratio of the wet-milling alkali-turn is 1 to 4 mL / g, the ball-milling time of the wet-milling alkali-turn is 2 to 4 hours, and the ball-milling speed of the wet-milling alkali-turn is 400 to 600 rpm.

[0029] Specifically, the wet grinding leaching residue mainly contains magnesium fluoride precipitate and calcium sulfate precipitate. After adding sodium hydroxide for wet grinding alkali conversion, the obtained alkali conversion slag mainly includes magnesium hydroxide, calcium hydroxide and calcium sulfate, and the obtained alkali conversion liquid mainly includes fluoride ions, sodium ions and hydroxide ions.

[0030] In some possible implementations, in S5, the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process in S3.

[0031] Specifically, the mother liquor of sodium fluoride crystallization is recycled to the wet grinding alkali conversion process, which can make the conversion of fluorine-containing substances into sodium fluoride more thorough and achieve efficient recovery of fluoride ions.

[0032] In some possible implementations, in S6, the molar amount of the aqueous sulfuric acid solution is 1.5 to 2 times the theoretical reaction molar amount of calcium and magnesium in the alkali-converted slag, the acid leaching time is 0.2 to 2 hours, the acid leaching temperature is 25 to 50°C, and the liquid-to-solid ratio of the aqueous sulfuric acid solution to the alkali-converted slag is 8 to 14 mL / g; in S6, the acid leached slag is used as a building material.

[0033] Specifically, the aqueous sulfuric acid solution reacts with magnesium hydroxide and calcium hydroxide to generate calcium sulfate and magnesium sulfate. The main component of the acid leaching residue is calcium sulfate, which can be used as a building material to achieve resource recycling.

[0034] In some possible implementations, in S7, the amount of calcium nitrate added is 1 to 2 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 0.5 to 2 hours, the reaction temperature is 25 to 60°C, and the liquid-to-solid ratio of the acid leaching solution to the calcium nitrate is 6 to 14 mL / g; in S7, the regenerated slag is used as a building material; in S8, the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process in S1; and the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process in S7.

[0035] Specifically, calcium nitrate can be derived from wet grinding leachate. Calcium nitrate reacts with magnesium sulfate in the acid leachate to generate a regeneration liquid mainly composed of magnesium nitrate and a regeneration slag mainly composed of calcium sulfate. The regeneration liquid is evaporated and crystallized to obtain magnesium nitrate hexahydrate. The obtained magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process to react with calcium fluoride, thereby realizing the recycling of resources. The regeneration slag is used as a building material to realize resource recycling.

[0036] In order to further illustrate the technical solution of the present application in detail to support the technical problem to be solved by the present application, the preparation method is described below by specific comparative examples and examples, such as implementation examples 1 to 5 and comparative examples 1 to 2.

[0037] Implementation Example 1

[0038] A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, specifically comprising the following steps:

[0039] Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; the amount of magnesium nitrate hexahydrate added is 1.2 times the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 6 hours, and the roasting temperature is 400°C;

[0040] Wet milling leaching: wet milling leaching the roasted slag obtained by the low-temperature molten salt conversion, solid-liquid separation, to obtain wet milling leaching slag and wet milling leaching liquid; the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 8, the liquid-to-solid ratio of the wet milling leaching is 8 mL / g, the ball milling time of the wet milling leaching is 0.8 hours, and the ball milling speed of the wet milling leaching is 160 rpm;

[0041] Wet milling and alkali conversion: adding sodium hydroxide to the wet milling leaching residue obtained by the wet milling leaching to carry out wet milling and alkali conversion, solid-liquid separation, and obtaining alkali conversion residue and alkali conversion liquid; the amount of sodium hydroxide added is 2 times the theoretical reaction molar amount of fluoride in the wet milling leaching residue, the ball-to-material ratio of the wet milling alkali conversion is 12, the liquid-to-solid ratio of the wet milling alkali conversion is 4 mL / g, the ball milling time of the wet milling alkali conversion is 4 hours, and the ball milling speed of the wet milling alkali conversion is 600 rpm;

[0042] Neutralization: neutralizing the alkali liquid obtained by the wet grinding alkali conversion with hydrofluoric acid to obtain a neutralized liquid;

[0043] Sodium fluoride evaporation crystallization: the neutralized solution obtained by the neutralization is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process;

[0044] Acid leaching: Acid leaching is performed on the alkali-transformed slag obtained by wet grinding alkali-transformed with an aqueous sulfuric acid solution, and solid-liquid separation is performed to obtain acid leaching slag and acid leaching liquid; the acid leaching slag is used as a building material; the molar amount of the aqueous sulfuric acid solution is twice the theoretical reaction molar amount of calcium and magnesium in the alkali-transformed slag, the acid leaching time is 2 hours, the acid leaching temperature is 45° C., and the liquid-solid ratio of the aqueous sulfuric acid solution to the alkali-transformed slag is 14 mL / g;

[0045] Regeneration of magnesium nitrate: adding calcium nitrate to the acid leaching solution obtained in the acid leaching to react, separating the solid and the liquid to obtain regenerated slag and regenerated liquid; the regenerated slag is used as a building material; the amount of calcium nitrate added is 1.9 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 1 hour, the reaction temperature is 40° C., and the liquid-solid ratio of the acid leaching solution to the calcium nitrate is 10 mL / g;

[0046] Magnesium nitrate evaporation crystallization: the regeneration liquid obtained in the magnesium nitrate regeneration process is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor; the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process; the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process.

[0047] Implementation Example 2

[0048] A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, specifically comprising the following steps:

[0049] Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; the amount of magnesium nitrate hexahydrate added is 1.8 times the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 8 hours, and the roasting temperature is 400°C;

[0050] Wet milling leaching: wet milling leaching the roasted slag obtained by the low-temperature molten salt conversion, solid-liquid separation, to obtain wet milling leaching slag and wet milling leaching liquid; the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 10, the liquid-to-solid ratio of the wet milling leaching is 6 mL / g, the ball milling time of the wet milling leaching is 1.3 hours, and the ball milling speed of the wet milling leaching is 180 rpm;

[0051] Wet milling and alkali conversion: adding sodium hydroxide to the wet milling leaching residue obtained by the wet milling leaching to carry out wet milling and alkali conversion, solid-liquid separation, and obtaining alkali conversion residue and alkali conversion liquid; the amount of sodium hydroxide added is 1.6 times the theoretical reaction molar amount of fluoride in the wet milling leaching residue, the ball-to-material ratio of the wet milling alkali conversion is 10, the liquid-to-solid ratio of the wet milling alkali conversion is 4 mL / g, the ball milling time of the wet milling alkali conversion is 4 hours, and the ball milling speed of the wet milling alkali conversion is 600 rpm;

[0052] Neutralization: neutralizing the alkali liquid obtained by the wet grinding alkali conversion with hydrofluoric acid to obtain a neutralized liquid;

[0053] Sodium fluoride evaporation crystallization: the neutralized solution obtained by the neutralization is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process;

[0054] Acid leaching: acid leaching the alkali-transformed slag obtained by wet grinding alkali-transformed with an aqueous sulfuric acid solution, and separating the solid and the liquid to obtain an acid leaching slag and an acid leaching solution; the acid leaching slag is used as a building material; the molar amount of the aqueous sulfuric acid solution is 1.7 times the theoretical reaction molar amount of calcium and magnesium in the alkali-transformed slag, the acid leaching time is 1.2 hours, the acid leaching temperature is 40° C., and the liquid-solid ratio of the aqueous sulfuric acid solution to the alkali-transformed slag is 10 mL / g;

[0055] Regeneration of magnesium nitrate: adding calcium nitrate to the acid leaching solution obtained in the acid leaching to react, separating the solid and the liquid to obtain regenerated slag and regenerated liquid; the regenerated slag is used as a building material; the amount of calcium nitrate added is 1.8 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 1.2 hours, the reaction temperature is 35° C., and the liquid-solid ratio of the acid leaching solution to the calcium nitrate is 12 mL / g;

[0056] Magnesium nitrate evaporation crystallization: the regeneration liquid obtained in the magnesium nitrate regeneration process is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor; the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process; the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process.

[0057] Implementation Example 3

[0058] A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, specifically comprising the following steps:

[0059] Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; the amount of magnesium nitrate hexahydrate added is 1.8 times the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 6 hours, and the roasting temperature is 200°C;

[0060] Wet milling leaching: wet milling leaching the roasted slag obtained by the low-temperature molten salt conversion, solid-liquid separation, to obtain wet milling leaching slag and wet milling leaching liquid; the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 8, the liquid-to-solid ratio of the wet milling leaching is 10 mL / g, the ball milling time of the wet milling leaching is 1.2 hours, and the ball milling speed of the wet milling leaching is 120 rpm;

[0061] Wet milling and alkali conversion: adding sodium hydroxide to the wet milling leaching residue obtained by the wet milling leaching to carry out wet milling and alkali conversion, solid-liquid separation, and obtaining alkali conversion residue and alkali conversion liquid; the amount of sodium hydroxide added is 1.6 times the theoretical reaction molar amount of fluoride in the wet milling leaching residue, the ball-to-material ratio of the wet milling alkali conversion is 10, the liquid-to-solid ratio of the wet milling alkali conversion is 3 mL / g, the ball milling time of the wet milling alkali conversion is 3 hours, and the ball milling speed of the wet milling alkali conversion is 500 rpm;

[0062] Neutralization: neutralizing the alkali liquid obtained in the wet grinding and leaching with hydrofluoric acid to obtain a neutralized liquid;

[0063] Sodium fluoride evaporation crystallization: the neutralized solution obtained by the neutralization is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process;

[0064] Acid leaching: the alkali-converted slag obtained by wet grinding is acid-leached with an aqueous sulfuric acid solution, and the solid-liquid separation is performed to obtain an acid-leached slag and an acid-leached solution; the acid-leached slag is used as a building material; the molar amount of the aqueous sulfuric acid solution is 1.8 times the theoretical reaction molar amount of calcium and magnesium in the alkali-converted slag, the acid leaching time is 2 hours, the acid leaching temperature is 50° C., and the liquid-solid ratio of the aqueous sulfuric acid solution to the alkali-converted slag is 14 mL / g;

[0065] Regeneration of magnesium nitrate: adding calcium nitrate to the acid leaching solution obtained in the acid leaching to react, separating the solid and the liquid to obtain regenerated slag and regenerated liquid; the regenerated slag is used as a building material; the amount of calcium nitrate added is 1.8 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 2 hours, the reaction temperature is 50° C., and the liquid-solid ratio of the acid leaching solution to the calcium nitrate is 14 mL / g;

[0066] Magnesium nitrate evaporation crystallization: the regeneration liquid obtained in the magnesium nitrate regeneration process is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor; the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process; the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process.

[0067] Implementation Example 4

[0068] A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, specifically comprising the following steps:

[0069] Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; the amount of magnesium nitrate hexahydrate added is twice the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 8 hours, and the roasting temperature is 200°C;

[0070] Wet milling leaching: wet milling leaching the roasted slag obtained by the low-temperature molten salt conversion, solid-liquid separation, to obtain wet milling leaching slag and wet milling leaching liquid; the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 10, the liquid-to-solid ratio of the wet milling leaching is 10mL / g, the ball milling time of the wet milling leaching is 1 hour, and the ball milling speed of the wet milling leaching is 200 rpm;

[0071] Wet milling and alkali conversion: adding sodium hydroxide to the wet milling leaching residue obtained by the wet milling leaching to carry out wet milling and alkali conversion, solid-liquid separation, and obtaining alkali conversion residue and alkali conversion liquid; the amount of sodium hydroxide added is 1.5 times the theoretical reaction molar amount of fluoride in the wet milling leaching residue, the ball-to-material ratio of the wet milling alkali conversion is 12, the liquid-to-solid ratio of the wet milling alkali conversion is 4 mL / g, the ball milling time of the wet milling alkali conversion is 4 hours, and the ball milling speed of the wet milling alkali conversion is 600 rpm;

[0072] Neutralization: neutralizing the alkali liquid obtained by the wet grinding alkali conversion with hydrofluoric acid to obtain a neutralized liquid;

[0073] Sodium fluoride evaporation crystallization: the neutralized solution obtained by the neutralization is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process;

[0074] Acid leaching: Acid leaching is performed on the alkali-transformed slag obtained by wet grinding alkali-transformed with an aqueous sulfuric acid solution, and solid-liquid separation is performed to obtain acid leaching slag and acid leaching liquid; the acid leaching slag is used as a building material; the molar amount of the aqueous sulfuric acid solution is twice the theoretical reaction molar amount of calcium and magnesium in the alkali-transformed slag, the acid leaching time is 2 hours, the acid leaching temperature is 50° C., and the liquid-solid ratio of the aqueous sulfuric acid solution to the alkali-transformed slag is 14 mL / g;

[0075] Regeneration of magnesium nitrate: adding calcium nitrate to the acid leaching solution obtained in the acid leaching to react, separating the solid and the liquid to obtain regenerated slag and regenerated liquid; the regenerated slag is used as a building material; the amount of calcium nitrate added is twice the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 0.6 hours, the reaction temperature is 25°C, and the liquid-solid ratio of the acid leaching solution to the calcium nitrate is 10mL / g;

[0076] Magnesium nitrate evaporation crystallization: the regeneration liquid obtained in the magnesium nitrate regeneration process is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor; the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process; the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process.

[0077] Implementation Example 5

[0078] A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, specifically comprising the following steps:

[0079] Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; the amount of magnesium nitrate hexahydrate added is 1 times the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 2 hours, and the roasting temperature is 100°C;

[0080] Wet milling leaching: wet milling leaching the roasted slag obtained by the low-temperature molten salt conversion, solid-liquid separation, to obtain wet milling leaching slag and wet milling leaching liquid; the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 6, the liquid-to-solid ratio of the wet milling leaching is 4 mL / g, the ball milling time of the wet milling leaching is 0.5 hours, and the ball milling speed of the wet milling leaching is 100 rpm;

[0081] Wet milling and alkali conversion: adding sodium hydroxide to the wet milling leaching residue obtained by the wet milling leaching to carry out wet milling and alkali conversion, solid-liquid separation, and obtaining alkali conversion residue and alkali conversion liquid; the amount of sodium hydroxide added is 1 times the theoretical reaction molar amount of fluoride in the wet milling leaching residue, the ball-to-material ratio of the wet milling alkali conversion is 8, the liquid-to-solid ratio of the wet milling alkali conversion is 1 mL / g, the ball milling time of the wet milling alkali conversion is 2 hours, and the ball milling speed of the wet milling alkali conversion is 400 rpm;

[0082] Neutralization: neutralizing the alkali liquid obtained by the wet grinding alkali conversion with hydrofluoric acid to obtain a neutralized liquid;

[0083] Sodium fluoride evaporation crystallization: the neutralized solution obtained by the neutralization is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process;

[0084] Acid leaching: Acid leaching is performed on the alkali-transformed slag obtained by wet grinding alkali-transformed with an aqueous sulfuric acid solution, and solid-liquid separation is performed to obtain acid leaching slag and acid leaching liquid; the acid leaching slag is used as a building material; the molar amount of the aqueous sulfuric acid solution is 1.5 times the theoretical reaction molar amount of calcium and magnesium in the alkali-transformed slag, the acid leaching time is 0.2 hours, the acid leaching temperature is 25° C., and the liquid-solid ratio of the aqueous sulfuric acid solution to the alkali-transformed slag is 8 mL / g;

[0085] Regeneration of magnesium nitrate: adding calcium nitrate to the acid leaching solution obtained in the acid leaching to react, separating the solid and the liquid to obtain regenerated slag and regenerated liquid; the regenerated slag is used as a building material; the amount of calcium nitrate added is twice the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 1 hour, the reaction temperature is 35° C., and the liquid-solid ratio of the acid leaching solution to the calcium nitrate is 12 mL / g;

[0086] Magnesium nitrate evaporation crystallization: the regeneration liquid obtained in the magnesium nitrate regeneration process is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor; the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process; the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process.

[0087] Comparative Example 1

[0088] A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, specifically comprising the following steps:

[0089] Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; the amount of magnesium nitrate hexahydrate added is 0.8 times the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 2 hours, and the roasting temperature is 100°C;

[0090] Wet milling leaching: wet milling leaching the roasted slag obtained by the low-temperature molten salt conversion, solid-liquid separation, to obtain wet milling leaching slag and wet milling leaching liquid; the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 6, the liquid-to-solid ratio of the wet milling leaching is 4 mL / g, the ball milling time of the wet milling leaching is 0.5 hours, and the ball milling speed of the wet milling leaching is 100 rpm;

[0091] Wet milling and alkali conversion: adding sodium hydroxide to the wet milling leaching residue obtained by the wet milling leaching to carry out wet milling and alkali conversion, solid-liquid separation, and obtaining alkali conversion residue and alkali conversion liquid; the amount of sodium hydroxide added is 0.8 times the theoretical reaction molar amount of fluoride in the wet milling leaching residue, the ball-to-material ratio of the wet milling and alkali conversion is 8, the liquid-to-solid ratio of the wet milling and alkali conversion is 1 mL / g, the ball milling time of the wet milling and alkali conversion is 2 hours, and the ball milling speed of the wet milling and alkali conversion is 400 rpm;

[0092] Neutralization: neutralizing the alkali liquid obtained by the wet grinding alkali conversion with hydrofluoric acid to obtain a neutralized liquid;

[0093] Sodium fluoride evaporation crystallization: the neutralized solution obtained by the neutralization is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process;

[0094] Acid leaching: Acid leaching is performed on the alkali-transformed slag obtained by wet grinding alkali-transformed with an aqueous sulfuric acid solution, and solid-liquid separation is performed to obtain acid leaching slag and acid leaching liquid; the acid leaching slag is used as a building material; the molar amount of the aqueous sulfuric acid solution is 1.5 times the theoretical reaction molar amount of calcium and magnesium in the alkali-transformed slag, the acid leaching time is 0.2 hours, the acid leaching temperature is 25° C., and the liquid-solid ratio of the aqueous sulfuric acid solution to the alkali-transformed slag is 8 mL / g;

[0095] Regeneration of magnesium nitrate: adding calcium nitrate to the acid leaching solution obtained in the acid leaching to react, separating the solid and the liquid to obtain regenerated slag and regenerated liquid; the regenerated slag is used as a building material; the amount of calcium nitrate added is 1.5 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 0.2 hours, the reaction temperature is 25°C, and the liquid-solid ratio of the acid leaching solution to the calcium nitrate is 8 mL / g;

[0096] Magnesium nitrate evaporation crystallization: the regeneration liquid obtained in the magnesium nitrate regeneration process is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor; the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process; the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process.

[0097] Comparative Example 2

[0098] A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, specifically comprising the following steps:

[0099] Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to the fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; the amount of magnesium nitrate hexahydrate added is 0.8 times the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 2 hours, and the roasting temperature is 100°C;

[0100] Wet milling leaching: wet milling leaching the roasted slag obtained by the low-temperature molten salt conversion, solid-liquid separation, to obtain wet milling leaching slag and wet milling leaching liquid; the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 6, the liquid-to-solid ratio of the wet milling leaching is 4 mL / g, the ball milling time of the wet milling leaching is 0.5 hours, and the ball milling speed of the wet milling leaching is 100 rpm;

[0101] Wet milling and alkali conversion: adding sodium hydroxide to the wet milling leaching residue obtained by the wet milling leaching to carry out wet milling and alkali conversion, and separating the solid and the liquid to obtain alkali conversion residue and alkali conversion liquid; the amount of sodium hydroxide added is 1 times the theoretical reaction molar amount of fluoride in the wet milling leaching residue, the ball-to-material ratio of the wet milling and alkali conversion is 10, the liquid-to-solid ratio of the wet milling and alkali conversion is 2 mL / g, the ball milling time of the wet milling and alkali conversion is 1 hour, and the ball milling speed of the wet milling and alkali conversion is 600 rpm;

[0102] Neutralization: neutralizing the alkali liquid obtained by the wet grinding alkali conversion with hydrofluoric acid to obtain a neutralized liquid;

[0103] Sodium fluoride evaporation crystallization: the neutralized solution obtained by the neutralization is evaporated and crystallized to obtain sodium fluoride and sodium fluoride crystallization mother liquor; the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process;

[0104] Acid leaching: Acid leaching is performed on the alkali-transformed slag obtained by wet grinding alkali-transformed with an aqueous sulfuric acid solution, and solid-liquid separation is performed to obtain acid leaching slag and acid leaching liquid; the acid leaching slag is used as a building material; the molar amount of the aqueous sulfuric acid solution is 1.5 times the theoretical reaction molar amount of calcium and magnesium in the alkali-transformed slag, the acid leaching time is 0.2 hours, the acid leaching temperature is 25° C., and the liquid-solid ratio of the aqueous sulfuric acid solution to the alkali-transformed slag is 8 mL / g;

[0105] Regeneration of magnesium nitrate: adding calcium nitrate to the acid leaching solution obtained in the acid leaching to react, separating the solid and the liquid to obtain regenerated slag and regenerated liquid; the regenerated slag is used as a building material; the amount of calcium nitrate added is 1.8 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 1.6 hours, the reaction temperature is 40° C., and the liquid-solid ratio of the acid leaching solution to the calcium nitrate is 10 mL / g;

[0106] Magnesium nitrate evaporation crystallization: the regeneration liquid obtained in the magnesium nitrate regeneration process is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor; the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process; the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process.

[0107] The effects of fluorinated gypsum in the glass thinning industry treated by implementation examples 1 to 5 and comparison examples 1 to 2 are compared as follows:

[0108] The recovery rate of fluorine in fluorine-containing gypsum and the purity of the treated sodium fluoride were tested, and the results are shown in Table 1.

[0109] Table 1 Fluorine recovery and sodium fluoride purity

[0110] Example Fluorine recovery rate / % Sodium fluoride purity / % Implementation Example 1 97.77 91.89 Implementation Example 2 96.52 90.01 Implementation Example 3 99.72 87.01 Implementation Example 4 98.32 88.13 Implementation Example 5 97.89 90.5 Comparative Example 1 67.89 80.2 Comparative Example 2 77.77 80.15

[0111] It can be seen from Table 1 that the fluorine-containing gypsum produced in the glass thinning industry is treated by a method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry of the present invention. The fluorine recovery rates in Implementation Examples 1 to 5 are all above 96.5%, which can reach 99.72%, and the purity of sodium fluoride is all above 87%, which can reach 91.89%. In Comparative Examples 1 to 2, the fluorine recovery rate is as high as 77.77%, and the purity of sodium fluoride is as high as 80.2%. Whether it is the fluorine recovery rate or the purity of sodium fluoride, the comparative examples are lower than the implementation examples. The low-temperature molten salt conversion process and the wet grinding alkali conversion process of the present invention have a great influence on the fluorine recovery rate.

[0112] In summary, the method for comprehensive utilization of fluorine-containing gypsum in the glass thinning industry of the present invention has the following advantages: 1. It realizes efficient recovery of fluoride ions in fluorine-containing gypsum and efficient purification of sodium fluoride; 2. The obtained magnesium nitrate hexahydrate is reused in the low-temperature lava conversion process, and sustainable recycling of resources is also realized.

[0113] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry, characterized in that: The method for comprehensive utilization of fluorinated gypsum in the glass thinning industry comprises: S1. Low-temperature molten salt conversion: adding magnesium nitrate hexahydrate to fluorine-containing gypsum, mixing evenly, and roasting to obtain roasted slag; S2, wet grinding and leaching: wet grinding and leaching the roasted slag obtained in S1, and separating the solid and liquid to obtain wet grinding leaching slag and wet grinding leaching liquid; S3, wet grinding alkali conversion: adding sodium hydroxide to the wet grinding leaching residue obtained in S2 to carry out wet grinding alkali conversion, and separating the solid and liquid to obtain alkali conversion residue and alkali conversion liquid; S4, neutralization: neutralizing the alkali liquid obtained in S3 with hydrofluoric acid to obtain a neutralized liquid; S5, sodium fluoride evaporation crystallization: evaporating and crystallizing the neutralized solution obtained in S4 to obtain sodium fluoride and sodium fluoride crystallization mother liquor; S6, acid leaching: acid leaching the alkali-converted slag obtained in S3 with a sulfuric acid aqueous solution, and separating the solid and the liquid to obtain acid leaching slag and acid leaching liquid; S7, magnesium nitrate regeneration: adding calcium nitrate to the acid leaching solution obtained in S6 to react, separate the solid and liquid, and obtain regenerated slag and regenerated liquid; S8, magnesium nitrate evaporation crystallization: the regeneration liquid obtained in S7 is evaporated and crystallized to obtain magnesium nitrate hexahydrate and magnesium nitrate crystallization mother liquor.

2. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 1, characterized in that: In S1, the amount of magnesium nitrate hexahydrate added is 1.5 to 2 times the theoretical reaction molar amount of fluoride in the fluorine-containing gypsum, the roasting time is 2 to 8 hours, and the roasting temperature is 100 to 600°C.

3. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 2, characterized in that: In S2, the leaching solvent of the wet milling leaching is water, the ball-to-material ratio of the wet milling leaching is 6-10, the liquid-to-solid ratio of the wet milling leaching is 4-10 mL / g, the ball milling time of the wet milling leaching is 0.5-1.5 hours, and the ball milling speed of the wet milling leaching is 100-200 rpm.

4. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 3, characterized in that: In S3, the amount of sodium hydroxide added is 1 to 2 times the theoretical reaction molar amount of fluoride in the wet-milled leaching residue, the ball-to-material ratio of the wet-milling alkali-milling is 8 to 12, the liquid-to-solid ratio of the wet-milling alkali-milling is 1 to 4 mL / g, the ball-milling time of the wet-milling alkali-milling is 2 to 4 hours, and the ball-milling speed of the wet-milling alkali-milling is 400 to 600 rpm.

5. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 4, characterized in that: In S5, the sodium fluoride crystallization mother liquor is recycled to the wet grinding alkali conversion process in S3.

6. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 5, characterized in that: In S6, the molar amount of the aqueous sulfuric acid solution is 1.5 to 2 times the theoretical reaction molar amount of calcium and magnesium in the alkali-converted slag, the acid leaching time is 0.2 to 2 hours, the acid leaching temperature is 25 to 50°C, and the liquid-to-solid ratio of the aqueous sulfuric acid solution to the alkali-converted slag is 8 to 14 mL / g.

7. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 6, characterized in that: In S6, the acid leaching residue is used as a building material.

8. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 7, characterized in that: In S7, the amount of calcium nitrate added is 1 to 2 times the theoretical reaction molar amount of magnesium in the acid leaching solution, the reaction time is 0.5 to 2 hours, the reaction temperature is 25 to 60° C., and the liquid-to-solid ratio of the acid leaching solution to the calcium nitrate is 6 to 14 mL / g.

9. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 8, characterized in that: In S7, the regenerated slag is used as a building material.

10. A method for comprehensive utilization of fluorinated gypsum in the glass thinning industry as claimed in claim 9, characterized in that: In S8, the magnesium nitrate hexahydrate is recycled to the low-temperature molten salt conversion process in S1; and the magnesium nitrate crystallization mother liquor is recycled to the magnesium nitrate regeneration process in S7.

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