Method for multi-source fluorine-containing solid waste collaborative safe disposal and full-component utilization

Abstract

The present application belongs to the technical field of solid waste resource utilization, and particularly relates to a method for collaborative safe disposal and full-component utilization of multi-source fluorine-containing solid waste. The method is used for treating multi-source fluorine-containing solid waste to obtain standby material; the standby material is placed in a mechanical activation and high-pressure environment integrated reaction device, and a leaching reagent is added for leaching; after leaching reaction, leaching residue and leaching solution are separated by vacuum filtration; an oxidizing agent is added to the leaching solution for oxidation treatment, then an inducing agent is added and the pH value is adjusted, and then crystallization and solid-liquid separation are sequentially performed to obtain cryolite and filtrate; the leaching residue and silicon-containing solid waste are wet-mixed at a certain mass ratio, an alkali catalyst is added, and curing, steam pressure and shaping treatments are performed to obtain an alkali-activated gel material. The present application relies on the component complementarity of multi-source fluorine-containing solid waste, and realizes collaborative safe disposal and full-component utilization of multi-source fluorine-containing solid waste through innovative ideas and technical means such as inducing agent regulation of solution ion composition and multi-field collaborative strengthening of leaching.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive utilization technology of solid waste resources, specifically relating to a method for the synergistic and safe disposal and full-component utilization of multi-source fluorine-containing solid waste. Background Technology

[0002] Currently, the preparation of hydrofluoric acid, the synthesis of sodium fluoride, and the production of electrolytic aluminum all generate large amounts of solid waste rich in soluble fluorides, such as fluorogypsum, fluorosilicone slag, and waste refractory materials. Their significant leaching toxicity poses a serious threat to the ecological environment. Furthermore, these fluorine-containing solid wastes mainly contain low-value components such as calcium sulfate, silica, and nepheline, lacking high-value utilization potential. Therefore, achieving synergistic detoxification and high-value utilization of these multi-source fluorine-containing solid wastes can provide technological support for promoting ecological civilization. Domestic and international technologies for treating these fluorine-containing solid wastes can be classified into the following categories:

[0003] The first method is leaching and landfill, which involves sequentially refining and compressing fluoride-containing solid waste, then landfilling it in a dedicated site equipped with a leaching recycling system. A collection pit is used to centrally collect the leached solution and rainwater runoff, thus preventing soluble fluorides from polluting the surrounding soil and water sources. Its disadvantages include the consumption of large amounts of land resources, serious environmental pollution risks, and the ineffective utilization of valuable resources.

[0004] The second method involves the disposal of building materials. This primarily utilizes the retarding properties of calcium sulfate and the cementitious activity of silica-containing mineral phases in fluorine-containing solid waste. The fluorine-containing solid waste, crushed to a certain particle size, is used as an admixture in the preparation of cement or non-fired cementitious materials. The soluble fluorides are deeply solidified in the cement or cementitious system, thus achieving the detoxification and resource utilization of the fluorine-containing solid waste. Its disadvantage is that the selling price of fluorine-containing solid waste is low, resulting in limited economic benefits.

[0005] The third method is low-cost calcium source solidification, which mainly utilizes the solidification characteristics of soluble fluorides in fluorine-containing solid waste. This is achieved by adding low-cost calcium sources such as quicklime, hydrated lime, and calcium hypochlorite to stably solidify the soluble fluorides. Its disadvantages are that the soluble fluorides, which have high-value application potential, are converted into CaF2, failing to achieve high-value utilization. Furthermore, the large amount of solid residue generated poses a secondary pollution risk, and there is a lack of resource utilization pathways.

[0006] The fourth method is high-temperature treatment, which is based on the thermal volatilization characteristics of soluble fluorides in fluorinated solid waste. High-temperature equipment is used to heat-treat the fluorinated solid waste at 1000℃, causing the soluble fluorides to undergo a phase change and escape in gaseous form. These fluorides are then recovered through a condensation system, thus achieving the detoxification and disposal of the fluorinated solid waste. Its disadvantages are that high-temperature treatment consumes a large amount of energy and generates carbon emissions; the fluorinated flue gas severely corrodes the lining of the high-temperature equipment; and the remaining solid residue cannot be utilized as a resource. Summary of the Invention

[0007] To address the problems existing in the prior art, the main objective of this invention is to propose a method for the synergistic and safe disposal and full-component utilization of multi-source fluorine-containing solid waste. This method enables the clean extraction and high-value product conversion of soluble fluorides from multi-source fluorine-containing solid waste, as well as the full-scale utilization of non-fluorine components. The method is characterized by low cost, short process, and significant economic benefits.

[0008] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0009] A method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste includes the following steps:

[0010] S1. Multi-stage crushing and screening of multi-source fluorine-containing solid waste to obtain spare materials;

[0011] S2. Place the spare material in a high-temperature ball mill with a polytetrafluoroethylene liner, add leaching agent for leaching, and after the leaching reaction is completed, separate the leaching residue and leaching liquid by vacuum filtration.

[0012] S3. Add the oxidant to the leachate for oxidation treatment;

[0013] S4. After oxidation treatment, an inducing agent is added and the pH is adjusted. The mixture is then subjected to crystallization and solid-liquid separation to obtain cryolite and filtrate.

[0014] S5. The leaching residue and silicon-containing solid waste are wet-mixed at a certain mass ratio, an alkaline catalyst is added, and after curing, autoclaving and shaping, an alkaline-activated gel material is obtained.

[0015] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste described in this invention, in step S1, the multi-source fluorine-containing solid waste is one or more of fluorogypsum, fluorosilicone slag, and waste refractory materials.

[0016] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste described in this invention, in step S1, the particle size range of the spare material is one of <3mm, <1mm, <0.15mm, and <0.074mm.

[0017] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste described in this invention, the liquid-solid ratio of the leaching agent to the standby material is 5:1-100:1, the leaching agent is one or both of aqueous solution and sodium aluminate solution, the leaching is multi-stage leaching, the first stage leaching solution is a high-concentration leaching solution, and the second and subsequent stages leaching solutions are low-concentration leaching solutions.

[0018] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste described in this invention, in step S2, the leaching temperature is 20-200℃, the leaching time is 10-180min, and the vibration frequency is 0-2000rpm.

[0019] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluoride-containing solid waste described in this invention, in step S3, the leachate is a high-concentration leachate, the oxidant is one or more of hydrogen peroxide, potassium permanganate, sodium hypochlorite, and concentrated sulfuric acid, the amount of oxidant added is 0.1-1% by volume, the oxidation temperature is 20-80℃, and the oxidation time is 10-60 min.

[0020] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste according to the present invention, in step S4, the filtrate is returned to the high-temperature ball mill of step S2.

[0021] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste described in this invention, in step S4, the inducing agent is one or more of aluminum fluoride, sodium aluminate, alumina, and aluminum hydroxide, the amount of inducing agent added is 0.1-10% by volume, the pH is adjusted to 4-9, the crystallization temperature is 20-80℃, and the crystallization time is 1-24h.

[0022] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste described in this invention, in step S5, the mass ratio of leaching residue to silicon-containing solid waste is 1:99-40:60, and the amount of alkaline catalyst added is 1-18 wt%.

[0023] As a preferred embodiment of the method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste described in this invention, in step S5, the silicon-containing solid waste is one or more of electrolytic manganese slag, lead-zinc slag, gold slag, fly ash, and slag; the alkaline catalyst is one or more of quicklime, carbide slag, and hydrated lime.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention leverages the complementary nature of components in multi-source fluorine-containing solid waste. Through innovative approaches and technologies such as inducing agents to regulate the ion composition of the solution and multi-field synergistic enhancement of leaching, it achieves the synergistic and safe disposal and full-component utilization of multi-source fluorine-containing solid waste. The disposal process proposed in this invention does not generate wastewater, waste gas, or waste residue. The leaching agents are inexpensive and suitable for recycling. Soluble fluorides are converted into high-value cryolite products, and the leaching residue is suitable for preparing cementitious materials, resulting in significant environmental, economic, and social benefits. Detailed Implementation

[0026] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] According to one aspect of the present invention, the present invention provides the following technical solution:

[0028] A method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste includes the following steps:

[0029] S1. Multi-stage crushing and screening of multi-source fluorine-containing solid waste to obtain spare materials;

[0030] S2. Place the spare material in a high-temperature ball mill with a polytetrafluoroethylene liner, add leaching agent for leaching, and after the leaching reaction is completed, separate the leaching residue and leaching liquid by vacuum filtration.

[0031] S3. Add the oxidant to the leachate for oxidation treatment;

[0032] S4. After oxidation treatment, an inducing agent is added and the pH is adjusted. The mixture is then subjected to crystallization and solid-liquid separation to obtain cryolite and filtrate.

[0033] S5. The leaching residue and silicon-containing solid waste are wet-mixed at a certain mass ratio, an alkaline catalyst is added, and after curing, autoclaving and shaping, an alkaline-activated gel material is obtained.

[0034] The present invention relates to multi-source fluorine-containing solid waste generated by different industries, specifically, it can be one or more of fluorogypsum, fluorosilicone slag, and waste refractory materials.

[0035] First, this invention leverages the abundant soluble fluoride content in multi-source fluoride-containing solid waste to efficiently extract soluble fluorides through a multi-field synergistic leaching device combined with green leaching agents. In-situ mechanical activation during the leaching process enhances the contact between solid particles and the leaching agent by reducing particle size and increasing specific surface area, thereby promoting the dissolution and removal of soluble fluorides. The leaching process takes place in a closed device, where the leaching agent vaporizes at a high temperature, creating a high-pressure environment. The lattice defects formed by in-situ mechanical activation effectively increase the diffusion rate of the leaching agent into the solid particles. Under the multi-field coupling effect of the in-situ mechanical activation and the high-pressure environment, a multi-field enhancement effect is achieved, resulting in a leaching rate of soluble fluorides in multi-source fluoride-containing solid waste ≥99.5%. Simultaneously, the leaching agent used in this invention has the technical advantages of high solubility, low cost, and no risk of secondary pollution. More importantly, both the low-concentration leachate and the residual filtrate after high-value product conversion can be recycled back to the leaching stage, demonstrating significant economic, environmental, and sustainable development.

[0036] Furthermore, the leachate is rich in Na and F elements. A simple process combination of oxidation treatment, inducer addition, pH control, and solid-liquid separation achieves the high-value conversion of soluble fluoride into cryolite. Oxidation treatment regulates the solution environment and removes some cyanide introduced from fluorine-containing solid waste. The inducer regulates the ionic composition of the solution without introducing impurities, forming a precursor solution with appropriate Na, Al, and F concentrations. pH control of the precursor solution is achieved through pH adjustment to prevent Cl- contamination. - SO4 2- NO 3- By introducing acidic anions, cryolite products with high molecular weight ratio (≥2.8), qualified elemental composition (F≥52.0wt%, Al≥12.0wt%, Na≤52.0wt%) and low loss on ignition (≤2.5wt%) were successfully prepared using high-concentration leachate.

[0037] Finally, in one aspect, this invention employs a blend of multi-source fluorine-containing solid waste with both high and low soluble fluorine concentrations to provide a suitable F- concentration for the subsequent cryolite precursor solution, thereby avoiding excessive F- concentrations. - Residues cause secondary pollution. On the other hand, multi-source fluorine-containing solid waste with gelling activity and retarding properties is used for blending. After the soluble fluorine leaching process, the residual mixed leaching residue possesses both gelling activity and retarding properties, which not only ensures the mechanical properties of the prepared cementitious material but also eliminates the need for retarder addition, thus reducing production costs. Through the above process design, leaching residue was successfully used to prepare materials with qualified mechanical properties (≥4MPa) and leaching toxicity (F... - Cementitious materials with a concentration of ≤5 mg / L.

[0038] Preferably, in step S1, the particle size range of the spare material is one of <3mm, <1mm, <0.15mm, and <0.074mm.

[0039] Preferably, in step S2, the liquid-solid ratio of the leaching agent to the prepared material is 5:1-100:1, the leaching agent is one or both of aqueous solution and sodium aluminate solution, and the leaching is multi-stage leaching, with the first stage leaching solution being a high-concentration leaching solution and the second and subsequent stages leaching solutions being low-concentration leaching solutions.

[0040] Preferably, in step S2, the leaching temperature is 20-200℃, the leaching time is 10-180min, and the vibration frequency is 0-2000rpm.

[0041] Preferably, in step S3, the leachate is a high-concentration leachate, the oxidant is one or more of hydrogen peroxide, potassium permanganate, sodium hypochlorite, and concentrated sulfuric acid, the amount of oxidant added is 0.1% to 1% by volume, the oxidation temperature is 20-80℃, and the oxidation time is 10-60 min.

[0042] Preferably, in step S4, the filtrate is returned to the high-temperature ball mill of step S2.

[0043] Preferably, in step S4, the inducing agent is one or more of aluminum fluoride, sodium aluminate, aluminum oxide, and aluminum hydroxide, the amount of inducing agent added is 0.1-10% by volume, the pH is adjusted to 4-9, the crystallization temperature is 20-80℃, and the crystallization time is 1-24h.

[0044] Preferably, in step S5, the mass ratio of leaching residue to silicon-containing solid waste is 1:99-40:60, and the amount of alkaline catalyst added is 1-18 wt%.

[0045] Preferably, in step S5, the silicon-containing solid waste is one or more of electrolytic manganese slag, lead-zinc slag, gold slag, fly ash, and slag; the alkaline catalyst is one or more of quicklime, carbide slag, and hydrated lime.

[0046] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0047] Example 1

[0048] A method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste includes the following steps:

[0049] S1. The waste refractory material is subjected to multi-stage crushing and screening in sequence to obtain spare material with a particle size range of <0.15mm;

[0050] S2. The prepared materials are loaded into a high-temperature ball mill with a polytetrafluoroethylene liner. Then, an aqueous solution is added at a liquid-to-solid ratio of 80:1. The leaching temperature is 80℃, the leaching time is 60 minutes, and the vibration frequency is 600 rpm. After the leaching reaction is complete, the leaching residue, primary leaching solution, and secondary leaching solution are separated by vacuum filtration. The primary leaching solution is a high-concentration solution, used for cryolite synthesis. The secondary leaching solutions are low-concentration solutions, recycled for the leaching process. The leaching rate of soluble fluorides is 99.78%.

[0051] S3. Add 0.2% hydrogen peroxide to the high-concentration leachate for oxidation treatment at 80℃ for 40 minutes. The leaching rate of highly toxic cyanide was 99.51%.

[0052] S4. After oxidation treatment, 5% sodium aluminate is added to the high-concentration leachate, and the pH is adjusted to 6. Crystallization and solid-liquid separation are then performed sequentially to obtain cryolite product and filtrate. The filtrate is returned to the leaching stage for recycling. The crystallization temperature is 20℃, and the crystallization time is 24 hours.

[0053] S5. The leaching residue and lead-zinc slag are wet-mixed at a mass ratio of 10:90, and then 15% quicklime is added. After curing, autoclaving and shaping, alkali-activated cementitious material is obtained.

[0054] In this embodiment, the molecular ratio of the synthesized cryolite is 2.88, the contents of F, Al and Na elements are 56.62%, 12.57% and 30.81% respectively, and the loss on ignition is 2.4wt%; the compressive strength of the alkali-activated cementitious material is 4.3MPa, and the F- leaching concentration is 2.81mg / L.

[0055] Example 2

[0056] A method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste includes the following steps:

[0057] S1. The waste refractory materials and fluorogypsum are subjected to multi-stage crushing and screening processes in sequence to obtain spare materials with a particle size range of <0.074mm.

[0058] S2. Load the prepared materials into a high-temperature ball mill with a polytetrafluoroethylene liner, then add an aqueous solution at a liquid-to-solid ratio of 50:1. The leaching temperature is 60℃, the leaching time is 60 min, and the vibration frequency is 800 rpm. After the leaching reaction is complete, separate the leaching residue and the primary leaching solution by vacuum filtration. The leaching solution is then processed in multiple stages. One stage leaching solution is a high-concentration solution used for cryolite synthesis, while the other stages are low-concentration solutions recycled for the leaching process. The leaching rate of soluble fluorides is 99.84%.

[0059] S3. Add 0.1% hydrogen peroxide to the high-concentration leachate for oxidation treatment at 80℃ for 30 minutes. The leaching rate of highly toxic cyanide was 99.92%.

[0060] S4. After oxidation treatment, 3% sodium aluminate is added to the high-concentration leachate, and the pH is adjusted to 7. Crystallization and solid-liquid separation are then performed sequentially to obtain cryolite product and filtrate. The filtrate is returned to the leaching stage for recycling. The crystallization temperature is 20℃, and the crystallization time is 12 hours.

[0061] S5 wet-mixes leaching residue and lead-zinc slag at a mass ratio of 5:95, then adds 15% quicklime, and after curing, autoclaving, and shaping, obtains an alkali-activated cementitious material.

[0062] In this embodiment, the molecular ratio of the synthesized cryolite is 2.87, and the contents of F, Al, and Na are 56.20%, 12.72%, and 31.08%, respectively, with a loss on ignition of 2.2 wt%. The compressive strength of the alkali-activated cementitious material is 5.0 MPa, and the F content is... - The leaching concentration was 1.121 mg / L.

[0063] Example 3

[0064] A method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste includes the following steps:

[0065] S1. The waste refractory materials, fluorosilicone slag and fluorogypsum are subjected to multi-stage crushing and screening in sequence to obtain spare materials with a particle size range of <0.15mm.

[0066] S2. The prepared materials are loaded into a high-temperature ball mill with a polytetrafluoroethylene liner. Then, an aqueous solution is added at a liquid-to-solid ratio of 60:1. The leaching temperature is 70℃, the leaching time is 60 minutes, and the vibration frequency is 1000 rpm. After the leaching reaction is complete, the leaching residue and primary leaching solution are separated by vacuum filtration. The resulting leaching solution consists of multiple stages. The primary stage leaching solution is a high-concentration solution used for cryolite synthesis. The secondary stage leaching solution is a low-concentration solution, which is recycled for the leaching process. The leaching rate of soluble fluorides is 99.67%.

[0067] S3. Add 0.1% hydrogen peroxide to the high-concentration leachate for oxidation treatment at 60℃ for 20 minutes. The leaching rate of highly toxic cyanide was 99.74%.

[0068] S4. After oxidation treatment, 4% sodium aluminate is added to the high-concentration leachate, and the pH is adjusted to 5. Crystallization and solid-liquid separation are then performed sequentially to obtain cryolite product and filtrate. The filtrate is returned to the leaching stage for recycling. The crystallization temperature is 40℃, and the crystallization time is 6 hours.

[0069] S5. The leaching residue and lead-zinc slag are wet-mixed at a mass ratio of 15:85, and then 15% quicklime is added. After curing, autoclaving and shaping, alkali-activated cementitious material is obtained.

[0070] In this embodiment, the molecular ratio of the synthesized cryolite is 2.80, and the contents of F, Al, and Na are 56.13%, 12.95%, and 30.92%, respectively, with a loss on ignition of 2.3 wt%. The compressive strength of the alkali-activated cementitious material is 4.0 MPa, and the F content is... - The leaching concentration was 4.68 mg / L.

[0071] Example 4

[0072] A method for the synergistic safe disposal and full-component utilization of multi-source fluorine-containing solid waste includes the following steps:

[0073] S1. The waste refractory materials and fluorogypsum are subjected to multi-stage crushing and screening processes in sequence to obtain spare materials with a particle size range of <0.074mm.

[0074] S2. The prepared materials are loaded into a high-temperature ball mill with a polytetrafluoroethylene liner. Sodium aluminate solution is then added at a liquid-to-solid ratio of 60:1. The leaching temperature is 60℃, the leaching time is 60 minutes, and the vibration frequency is 1200 rpm. After the leaching reaction is complete, the leaching residue and primary leaching solution are separated by vacuum filtration. The primary leaching solution is a high-concentration solution used for cryolite synthesis. The secondary leaching solutions are low-concentration solutions recycled for the leaching process. The leaching rate of soluble fluorides is 99.52%.

[0075] S3. Add 0.05% hydrogen peroxide to the high-concentration leachate for oxidation treatment at 80℃ for 60 minutes. The leaching rate of highly toxic cyanide was 99.83%.

[0076] S4. After oxidation treatment, 1% aluminum hydroxide is added to the high-concentration leachate to adjust the pH to 5.5. The mixture is then subjected to crystallization and solid-liquid separation to obtain cryolite product and filtrate. The filtrate is returned to the leaching stage for recycling. The crystallization temperature is 20℃, and the crystallization time is 12 hours.

[0077] S5. The leaching residue and slag are wet-mixed at a mass ratio of 10:90, and then 15% quicklime is added. After curing, autoclaving and shaping, alkali-activated cementitious material is obtained.

[0078] In this embodiment, the molecular ratio of the synthesized cryolite is 2.83, and the contents of F, Al, and Na are 56.02%, 12.88%, and 31.10%, respectively, with a loss on ignition of 2.15 wt%. The compressive strength of the alkali-activated cementitious material is 4.4 MPa, and the F content is... - The leaching concentration was 3.15 mg / L.

[0079] Comparative Example 1

[0080] A method for treating multi-source fluorine-containing solid waste includes the following steps:

[0081] S1. The waste refractory material is subjected to multi-stage crushing and screening in sequence to obtain spare material with a particle size range of <0.15mm;

[0082] S2. The prepared materials are loaded into a magnetically stirred leaching container, and then an aqueous solution is added at a liquid-to-solid ratio of 80:1. The leaching temperature is 80℃, the leaching time is 60 min, and the stirring rate is 600 r / min. After the leaching reaction is completed, the leaching residue and primary leachate are separated by vacuum filtration. The high-concentration leachate is used for cryolite synthesis, and the low-concentration leachate is recycled for the leaching process. The leaching rate of soluble fluorides is 97.12%.

[0083] S3. Add 0.2% hydrogen peroxide to the high-concentration leachate for oxidation treatment at 80℃ for 40 minutes. The leaching rate of highly toxic cyanide was 98.18%.

[0084] S4. After oxidation treatment, 5% sodium aluminate is added to the high-concentration leachate, and the pH is adjusted to 6. Crystallization and solid-liquid separation are then performed sequentially to obtain cryolite product and filtrate. The filtrate is returned to the leaching stage for recycling. The crystallization temperature is 20℃, and the crystallization time is 24 hours.

[0085] S5. The leaching residue and lead-zinc slag are wet-mixed at a mass ratio of 10:90, and then 15% quicklime is added. After curing, autoclaving and shaping, alkali-activated cementitious material is obtained.

[0086] In this comparative example, the molecular ratio of the synthetic cryolite was 2.53, and the contents of F, Al, and Na were 55.62%, 13.66%, and 29.48%, respectively, with a loss on ignition of 2.6 wt%. The compressive strength of the alkali-activated cementitious material was 3.2 MPa, and the F- leaching concentration was 64.88 mg / L.

[0087] In this comparative example, when leaching was performed using a conventional leaching device, the lack of synergistic enhancement from mechanical activation and high-pressure environment resulted in a reduced leaching rate, which also affected subsequent cryolite synthesis and cementitious material preparation.

[0088] Comparative Example 2

[0089] A method for treating multi-source fluorine-containing solid waste includes the following steps:

[0090] S1. The waste refractory materials and fluorogypsum are subjected to multi-stage crushing and screening processes in sequence to obtain spare materials with a particle size range of <0.074mm.

[0091] S2. The prepared materials are loaded into a magnetically stirred leaching container, and then an aqueous solution is added at a liquid-to-solid ratio of 50:1. The leaching temperature is 60℃, the leaching time is 60 min, and the stirring rate is 800 r / min. After the leaching reaction is completed, the leaching residue and primary leaching solution are separated by vacuum filtration. The high-concentration leaching solution is used for cryolite synthesis, and the low-concentration leaching solution is recycled for the leaching process. The leaching rate of soluble fluorides is 97.45%.

[0092] S3. Add 0.1% hydrogen peroxide to the high-concentration leachate for oxidation treatment at 80℃ for 30 minutes. The leaching rate of highly toxic cyanide was 98.33%.

[0093] S4. After oxidation treatment, 3% sodium aluminate is added to the high-concentration leachate, and the pH is adjusted to 7. Crystallization and solid-liquid separation are then performed sequentially to obtain cryolite product and filtrate. The filtrate is returned to the leaching stage for recycling. The crystallization temperature is 20℃, and the crystallization time is 12 hours.

[0094] S5. The leaching residue and lead-zinc slag are wet-mixed at a mass ratio of 5:95, and then 15% quicklime is added. After curing, autoclaving and shaping, alkali-activated cementitious material is obtained.

[0095] In this comparative example, the molecular ratio of the synthetic cryolite was 2.73, and the contents of F, Al, and Na were 55.48%, 12.92%, and 30.08%, respectively, with a loss on ignition of 2.2 wt%. The compressive strength of the alkali-activated cementitious material was 3.4 MPa, and the F- leaching concentration was 52.43 mg / L.

[0096] The comparative example shows that when the integrated mechanical activation and high-pressure environment reaction device is changed to a conventional leaching device at different particle sizes, the leaching rate will decrease due to the lack of synergistic enhancement effect of mechanical activation and high-pressure environment, which will also affect the subsequent cryolite synthesis and cementitious material preparation.

[0097] This invention leverages the complementary nature of components in multi-source fluorine-containing solid waste. Through innovative approaches and technologies such as inducing agents to regulate the ion composition of the solution and multi-field synergistic enhancement of leaching, it achieves the synergistic and safe disposal and full-component utilization of multi-source fluorine-containing solid waste. The disposal process proposed in this invention does not generate wastewater, waste gas, or waste residue. The leaching agents are inexpensive and suitable for recycling. Soluble fluorides are converted into high-value cryolite products, and the leaching residue is suitable for preparing cementitious materials, resulting in significant environmental, economic, and social benefits.

[0098] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for multi-source fluorine-containing solid waste collaborative safe disposal and full-component utilization, characterized in that, The method comprises the following steps: S1, multi-stage crushing and screening treatment is performed on multi-source fluorine-containing solid waste to obtain standby material; the multi-source fluorine-containing solid waste is at least one of fluorogypsum, fluorosilicon slag and waste refractory material; S2, the standby material is placed in a high-temperature ball mill with a polytetrafluoroethylene lining, a leaching agent is added for leaching, and after the leaching reaction is completed, the leaching residue and the leaching solution are separated by vacuum filtration; the liquid-solid ratio of the leaching agent to the standby material is 5:1-100:1, and the leaching agent is one or both of water and sodium metaaluminate solution; S3, an oxidizing agent is added to the leaching solution for oxidation treatment; the oxidizing agent is one or more of hydrogen peroxide, potassium permanganate, sodium hypochlorite and concentrated sulfuric acid, and the addition amount of the oxidizing agent is 0.1-1% by volume; S4, after the oxidation treatment, an inducing agent is added and the pH is adjusted to 4-9, and then crystallization and solid-liquid separation are sequentially performed to obtain cryolite and filtrate; the inducing agent is one or more of aluminum fluoride, sodium metaaluminate, aluminum oxide and aluminum hydroxide, and the addition amount of the inducing agent is 0.1-10wt%; S5, the leaching residue and silicon-containing solid waste are wet-mixed at a certain mass ratio, an alkali catalyst is added, and curing, autoclaving and shaping treatments are performed to obtain an alkali-activated gel material. The leaching rate of soluble fluorine in the multi-source fluorine-containing solid waste is ≥99.5%; the molecular ratio of cryolite is ≥2.8, the contents of F, Al and Na elements are respectively: ≥52.0wt%, ≥12.0wt% and ≤52.0wt%, the ignition loss is ≤2.5wt%; the F - content in the gel material is ≤5mg / L.

2. The method for multi-source fluorine-containing solid waste synergistic safe disposal and full-component utilization according to claim 1, characterized in that, In step S1, the particle size range of the standby material is one of <3mm, <1mm, <0.15mm and <0.074mm.

3. The method for multi-source fluorine-containing solid waste synergistic safe disposal and full-component utilization according to claim 1, characterized in that, In step S2, the leaching is multi-stage leaching, the first-stage leaching solution is a high-concentration leaching solution, and the second-stage and subsequent multi-stage leaching solutions are low-concentration leaching solutions.

4. The method for multi-source fluorine-containing solid waste synergistic safe disposal and full-component utilization according to claim 3, characterized in that, In step S2, the leaching temperature is 20-200℃, the leaching time is 10-180min, and the vibration frequency is 0-2000rpm.

5. The multi-source fluorine-containing solid waste co-safe disposal and full-component utilization method according to claim 3, characterized in that, In step S3, the leaching solution is a high-concentration leaching solution, the oxidation temperature is 20-80℃, and the oxidation time is 10-60min.

6. The multi-source fluorine-containing solid waste co-safe disposal and full- component utilization method according to claim 1, characterized in that, In step S4, the filtrate is returned to the high-temperature ball mill in step S2.

7. The multi-source fluorine-containing solid waste co-safe disposal and full- component utilization method according to claim 1, characterized in that, In step S4, the crystallization temperature is 20-80℃, and the crystallization time is 1-24h.

8. The method for multi-source fluorine-containing solid waste co-safe disposal and full-component utilization according to claim 1, characterized in that, In step S5, the mass ratio of the leaching residue to the silicon-containing solid waste is 1:99-40:60, and the addition amount of the alkali catalyst is 1-18wt%.

9. The multi-source fluorine-containing solid waste co-safe disposal and full- component utilization method according to claim 8, characterized in that, In step S5, the silicon-containing solid waste is one or more of electrolytic manganese residue, lead-zinc residue, gold mine residue and fly ash; and the alkali catalyst is one or more of quicklime, carbide slag and hydrated lime.