Treatment method of thallium-containing flue gas

Abstract

The invention provides a thallium-containing flue gas treatment method which comprises the following steps: thallium-containing flue gas is in contact with modified molybdenum disulfide, and the modified molybdenum disulfide adsorbs TlCl in the thallium-containing flue gas; the modified molybdenum disulfide is hydrothermal molybdenum disulfide and / or DMF (Dimethyl Formamide) intercalated molybdenum disulfide, and a plurality of lamellar fractures exist in a hydrothermal MoS2 and DMF-MoS2 layered structure, so that the modified molybdenum disulfide has abundant defect structures. The thallium adsorption effect in thallium-containing flue gas is remarkably optimized by utilizing excellent reaction activity and thermal stability of modified molybdenum disulfide in a high-temperature sulfur-containing flue gas environment.

Description

Technical Field

[0001] The invention belongs to the technical field of flue gas treatment, and in particular relates to a method for treating flue gas containing thallium. Background Art

[0002] Thallium is sulfur-loving and widely present in sulfide ores of metals such as lead, zinc, iron, and copper. Globally, 70% of thallium is bound to sulfides, while the remainder is bound to aluminosilicates or organic compounds. The development and smelting of non-ferrous minerals inevitably involves processes such as washing, beneficiation, and smelting, consuming large quantities of coal and ore raw materials, leading to a dramatic increase in thallium content in flue gas. It is estimated that approximately 2,000 to 5,000 tons of thallium are emitted into the environment annually worldwide, with the non-ferrous smelting industry generating a significant proportion of this gaseous thallium, and emissions are increasing with the expansion of the non-ferrous smelting industry.

[0003] The composition of smelting flue gas is relatively complex. It contains not only high concentrations of nitrogen oxides, but also high concentrations of SO2. Most adsorption materials will have their performance degraded or even become inactivated due to sulfur poisoning. According to Pearson's hard and soft acid-base theory, most heavy metals are soft metals and are classified as sulfides. They show a specific affinity for soft sulfide compounds -S, -Se and -Te. With the emergence of various metal sulfide adsorbents, this high affinity for heavy metals has been developed. Most metal sulfides have the advantages of transition metal composition and have excellent affinity for many heavy metals. Transition metal sulfides contain a large number of surface vacancies, defects and reaction sites in their structures, such as metal edge sites and S edge sites. These defects allow for a large number of adsorption active sites to remove heavy metals. At the same time, metal sulfides have good SO2 inhibition capabilities and are considered to be the best candidate materials for heavy metal capture in high-sulfur flue gas.

[0004] However, the actual smelting flue gas temperature is usually higher than 150°C. At this temperature, the active sulfur on the surface of most metal sulfides will decompose. Only MoS2 can maintain a certain degree of reactivity under conditions above this temperature. However, molybdenum disulfide has a two-dimensional layer structure. When heated, the layer structure collapses and becomes inactive. Therefore, it is urgent to develop a new method for treating thallium-containing flue gas to improve the thermal stability and reactivity of thallium adsorption materials for thallium adsorption in high-temperature sulfur-containing flue gas environments, thereby optimizing the thallium adsorption effect. Summary of the Invention

[0005] The present invention aims to solve the technical problem in the above-mentioned conventional technology that molybdenum disulfide materials collapse and deactivate in high-temperature thallium-containing flue gas, resulting in limited thermal stability and reaction activity of thallium adsorption, which affects the thallium adsorption effect in thallium-containing flue gas. The present invention provides a method for treating thallium-containing flue gas, comprising:

[0006] The thallium-containing flue gas contacts with modified molybdenum disulfide, and the modified molybdenum disulfide adsorbs TlCl in the thallium-containing flue gas; the modified molybdenum disulfide is hydrothermal molybdenum disulfide and / or DMF-intercalated molybdenum disulfide;

[0007] Wherein, the preparation of the DMF intercalated molybdenum disulfide comprises the steps of:

[0008] Mixing a molybdenum-containing reagent, a sulfur-containing reagent, and dimethylformamide to obtain a first mixed solution; subjecting the first mixed solution to a high-temperature pressure treatment at 120 to 260° C. for 4 to 20 hours, and performing solid-liquid separation to obtain the DMF-expanded molybdenum disulfide layer;

[0009] Wherein, the preparation of the hydrothermal molybdenum disulfide comprises the steps of:

[0010] A molybdenum-containing reagent, a sulfur-containing reagent and deionized water are mixed to obtain a second mixed solution; the second mixed solution is subjected to a high-temperature pressure treatment at 120 to 260° C. for 4 to 20 hours, and solid-liquid separation is performed to obtain the DMF-extended layer of molybdenum disulfide.

[0011] Furthermore, during the contact between the thallium-containing flue gas and modified molybdenum disulfide, the mass ratio of the modified molybdenum disulfide to thallium monochloride in the thallium-containing flue gas is 2-10:1, and the concentration of thallium monochloride in the thallium-containing flue gas is 0-5 mg / L.

[0012] Furthermore, the temperature of the thallium-containing flue gas is 150-350°C.

[0013] Furthermore, when the modified molybdenum disulfide is DMF-intercalated molybdenum disulfide, the temperature of the thallium-containing flue gas is 220-260°C.

[0014] Furthermore, when the modified molybdenum disulfide is hydrothermal molybdenum disulfide, the temperature of the thallium-containing flue gas is 190-220°C.

[0015] Furthermore, the composition of the thallium-containing flue gas also includes oxygen and / or hydrogen chloride. When the thallium-containing flue gas includes oxygen, the volume proportion of oxygen in the thallium-containing flue gas is not higher than 20% by volume; when the thallium-containing flue gas includes hydrogen chloride, the concentration of hydrogen chloride in the thallium-containing flue gas is not higher than 5000 ppm by volume.

[0016] Furthermore, the thallium-containing flue gas includes sulfur dioxide, and the volume proportion of the sulfur dioxide in the thallium-containing flue gas is not higher than 20%.

[0017] Furthermore, the flow rate of the thallium-containing flue gas is 0.5 to 3 L / min.

[0018] Furthermore, in the preparation of the DMF-intercalated molybdenum disulfide, the mass volume ratio of the molybdenum-containing reagent to the dimethylformamide is 1g:10~30ml; in the preparation of the hydrothermal molybdenum disulfide, the mass volume ratio of the molybdenum-containing reagent to the deionized water is 1g:10~30ml.

[0019] Furthermore, the molybdenum-containing reagent includes molybdenum element, the sulfur-containing reagent includes sulfur element, and the molar ratio of the molybdenum element to the sulfur element is 1:2-9.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] The present invention provides a method for treating flue gas containing thallium, using hydrothermal molybdenum disulfide and / or DMF intercalated molybdenum disulfide to treat flue gas containing thallium. The modified molybdenum disulfide has excellent reactivity and thermal stability in high-temperature sulfur-containing flue gas environments, significantly optimizing the adsorption of thallium in flue gas containing thallium. Compared with molybdenum disulfide in common technologies, hydrothermal MoS2 and DMF-MoS2 have more layer fractures in their layered structures, resulting in more boundary surfaces and richer defect structures, such as Figure 3 As shown. These defect structures are beneficial in providing more active unsaturated sites, significantly increasing the adsorption activity of the material surface. Due to the above advantages, the TlCl adsorption capacity of hydrothermal MoS2 and DMF-MoS2 layered structures in N2 atmosphere is significantly higher than that of other reported thallium adsorbents, reaching 110 mg / g and 160 mg / g respectively, which is about 3 to 4 times that of industrial molybdenum disulfide nanosheets. In addition, the modified molybdenum disulfide provides a support for expanding the interlayer spacing of molybdenum disulfide nanosheets synthesized by solvent thermal reaction, making molybdenum disulfide have higher thermal stability. Compared with the molybdenum disulfide inactivated by the collapse of the layer structure after heating in the commonly used technology, the present invention can maintain the original layer structure after heating, thereby maintaining the dethallium activity of the interlayer active sites and ensuring the adsorption efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 the structures shown in these drawings without paying any creative work.

[0023] Figure 1 The XRD patterns of DMF-intercalated molybdenum disulfide, hydrothermal molybdenum disulfide and industrial molybdenum disulfide in analysis example 1 of the present invention are shown.

[0024] Figure 2This is the EPR diagram of DMF-intercalated molybdenum disulfide, hydrothermal molybdenum disulfide and industrial molybdenum disulfide in analysis example 1 of the present invention.

[0025] Figure 3 (a) is a SEM image of hydrothermal molybdenum disulfide in Analytical Example 1 of the present invention, Figure 3 (b) TEM image of hydrothermal molybdenum disulfide in Analytical Example 1 of the present invention, Figure 3 (c) HR-TEM image of hydrothermal molybdenum disulfide in Analytical Example 1 of the present invention, Figure 3 (d) SEM image of DMF intercalated molybdenum disulfide in Analytical Example 1 of the present invention, Figure 3 (e) TEM image of DMF intercalated molybdenum disulfide in Analytical Example 1 of the present invention, Figure 3 (f) HR-TEM image of DMF-intercalated molybdenum disulfide in analytical example 1 of the present invention.

[0026] Figure 4(a) is a bar graph of the thallium adsorption capacity of hydrothermal molybdenum disulfide at different temperatures in Example 2 of the present invention, and Figure 4(b) is a bar graph of the thallium adsorption capacity of DMF-intercalated molybdenum disulfide at different temperatures in Example 2 of the present invention.

[0027] Figure 5(a) is a bar graph of the thallium adsorption capacity of hydrothermal molybdenum disulfide under different atmospheres at a flue gas temperature of 200°C in Example 3 of the present invention, and Figure 5(b) is a bar graph of the thallium adsorption capacity of DMF-intercalated molybdenum disulfide under different atmospheres at a flue gas temperature of 250°C in Example 3 of the present invention. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0029] Moreover, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] When numerical ranges are given in the examples, it should be understood that unless otherwise specified herein, both endpoints of each numerical range and any value between the two endpoints may be used. Unless otherwise defined, all technical and scientific terms used herein are consistent with the prior art as understood by those skilled in the art and the description of the present invention. Any prior art methods, devices, and materials similar or equivalent to those in the examples of the present invention may also be used to implement the present invention.

[0031] Among commonly used technologies, traditional adsorption materials such as activated carbon, nano-metal oxides, mesoporous carbon, and organic resins have been widely used in the adsorption and removal of heavy metals from flue gas. However, these materials often suffer from poor adsorption stability, poor selectivity, low adsorption capacity, uneven pore size distribution, extremely high production costs, and manufacturing difficulties. Although manganese oxide catalysts have excellent removal efficiency for flue gas thallium adsorption, the non-ferrous smelting industry is often exposed to high sulfur atmospheres, and SO2 has a significant inhibitory effect on the activity of manganese oxide catalysts. Therefore, the development of highly stable adsorbents that are resistant to sulfur and high temperatures is urgent.

[0032] Based on this, the present invention provides a method for treating thallium-containing flue gas, comprising:

[0033] The thallium-containing flue gas contacts with modified molybdenum disulfide, and the modified molybdenum disulfide adsorbs TlCl in the thallium-containing flue gas;

[0034] The modified molybdenum disulfide is hydrothermal molybdenum disulfide and / or DMF intercalated molybdenum disulfide, wherein the preparation of the DMF intercalated molybdenum disulfide comprises the following steps:

[0035] A molybdenum-containing reagent, a sulfur-containing reagent, and dimethylformamide are mixed to obtain a first mixed solution; wherein the molar ratio of the molybdenum element to the sulfur element in the molybdenum-containing reagent and the sulfur-containing reagent is 1:2-9; the first mixed solution is subjected to a high-temperature pressure treatment at 120-260° C. for 4-20 hours, and centrifuged to obtain the DMF-expanded molybdenum disulfide;

[0036] Wherein, the preparation of the hydrothermal molybdenum disulfide comprises the steps of:

[0037] A molybdenum-containing reagent, a sulfur-containing reagent and deionized water are mixed to obtain a second mixed solution; wherein the molar ratio of the molybdenum element to the sulfur element in the molybdenum-containing reagent and the sulfur-containing reagent is 1:2 to 9; the second mixed solution is subjected to a high-temperature pressure treatment at 120 to 260° C. for 4 to 20 hours, and centrifuged to obtain the DMF-expanded molybdenum disulfide layer.

[0038] In the present invention, the modified molybdenum disulfide used in the method for treating thallium-containing flue gas may be only DMF-intercalated molybdenum disulfide.

[0039] In the present invention, the molybdenum-containing reagent may include ammonium heptamolybdate, ammonium molybdate, molybdenum trioxide, and ammonium thiomolybdate. In some embodiments, the molybdenum-containing reagent may be ammonium heptamolybdate, which, as an inorganic substance, has a chemical formula of (NH4)6Mo7O 24Ammonium heptamolybdate is a colorless to pale green crystalline solid commonly used in the production of catalysts, metallic molybdenum, pigments, metal surface treatment agents, corrosion inhibitors, and trace element fertilizers. In this invention, it serves as a molybdenum source for the synthesis of molybdenum disulfide. Due to its ease of purification, solubility, and thermal dissociation, the NH3 released by its thermal dissociation can be readily released upon heating, thus minimizing contamination of molybdenum products. Therefore, ammonium heptamolybdate is widely used as a fundamental raw material for the production of high-purity molybdenum products.

[0040] In the present invention, the sulfur-containing reagent can be thiourea, thioacetamide, sodium sulfide, or sulfur. In some embodiments, the sulfur-containing reagent can be thiourea. Thiourea, as an organic sulfur-containing compound, has a chemical formula of CH4N2S and is a white and shiny crystal. It is commonly used in the manufacture of drugs, dyes, resins, compression molding powders, etc. In the present invention, it is used as a sulfur source for synthesizing molybdenum disulfide.

[0041] In the preparation of DMF-intercalated molybdenum disulfide of the present invention, dimethylformamide, also known as DMF, is a colorless, transparent liquid. As a widely used chemical raw material and solvent, it can be mixed with water and most organic solvents and has good solubility for a variety of organic and inorganic compounds.

[0042] As a strong polar solvent, N,N-dimethylformamide (DMF) can stably dissolve with organic / inorganic precursors due to its high thermal stability and good solubility, and shows unique advantages in the synthesis and modification of two-dimensional materials (such as MoS2). For example, in the liquid phase exfoliation process, DMF achieves efficient exfoliation by weakening the van der Waals force between MoS2 layers, significantly improving the dispersibility of nanosheets and their interfacial bonding strength with polymer matrices (such as Nafion, PVDF), providing a basis for the uniform construction of composite materials. In addition, the polar molecules of DMF can be strongly coupled with MoS2 precursors (such as (NH4)2MoS4) through coordination, regulating the interlayer intercalation behavior during the bottom-up synthesis process, inducing the expansion of the interlayer spacing and synchronously generating sulfur vacancies and edge active sites. This structural manipulation not only imparts MoS2 with higher interfacial reactivity (e.g., a three-fold increase in hydrogen evolution catalytic performance), but also suppresses high-temperature structural collapse by enhancing interlayer interactions, allowing it to maintain structural stability under harsh conditions. Furthermore, the DMF-H2O mixed solvent can further optimize the crystal structure of MoS2, enabling directional design of morphology (nanospheres, few-layer flakes) and crystal planes ((001) plane), providing highly active sites for optoelectronic devices and catalytic applications. Enhancing the interlayer van der Waals forces of MoS2 nanosheets is a key strategy for suppressing high-temperature structural failure. Strongly interacting molecular intercalation simultaneously strengthens interlayer bonding and lattice changes, inducing a significant increase in sulfur vacancies and edge defect sites, thereby enhancing adsorption performance.

[0043] In the preparation of DMF-intercalated molybdenum disulfide according to the present invention, ammonium heptamolybdate and thiourea are first mixed in a proportion, dissolved in a DMF solvent, and vigorously stirred for 30 minutes to obtain a first mixed solution. This ensures that the ammonium heptamolybdate, thiourea, and DMF are thoroughly mixed to promote efficient subsequent reactions. The mass-to-volume ratio of the molybdenum-containing reagent (e.g., ammonium heptamolybdate) to DMF can be 1 g:10-30 ml, and the DMF concentration can be 50-100%.

[0044] In the preparation of DMF-intercalated molybdenum disulfide of the present invention, ammonium heptamolybdate, thiourea, and DMF can also be mixed in deionized water or ethanol. Using deionized water as the solvent can avoid the adverse effects of organic solvents, such as inhibiting material dispersion, affecting the final crystal morphology and crystal structure of molybdenum disulfide, and affecting the properties of the modified molybdenum disulfide product.

[0045] In some more specific embodiments, in the preparation of DMF-intercalated molybdenum disulfide, ammonium molybdate and thiourea can be completely dissolved in 50 mL of DMF solution at a mass volume ratio of 1 g ammonium heptamolybdate to DMF of 10-30 mL, and the DMF concentration is 50-100%. The mixture is stirred vigorously for 30 minutes to obtain a first mixture. Subsequently, the first mixture is transferred to a 100 mL Teflon-lined autoclave and maintained at 120-260°C for 4-20 hours. After centrifugation, a black precipitate (denoted as DMF-MoS2) is obtained, which is then washed with deionized water and alcohol and finally dried at 80°C for 4-20 hours.

[0046] For example, the first mixture can be transferred into a 100 mL Teflon-lined autoclave and maintained at 140-220° C. for 10-20 hours.

[0047] As another example, ammonium molybdate and thiourea in a ratio of 1:2 to 1:6 can be completely dissolved in 50 mL of DMF solution, added to the solution, and vigorously stirred for 30 minutes to obtain a first mixture.

[0048] In the preparation of hydrothermal molybdenum disulfide according to the present invention, ammonium heptamolybdate and thiourea can be completely dissolved in 50 mL of deionized water at a mass-to-volume ratio of 1 g ammonium heptamolybdate to water of 10-30 mL. The mixture is then vigorously stirred for 30 minutes to obtain a second mixture. The mixture is then transferred to a 100 mL Teflon-lined autoclave and maintained at 120-260°C for 4-20 hours. After centrifugation, a black precipitate (referred to as hydrothermal MoS2) is obtained, which is then washed with deionized water and alcohol and finally dried at 80°C for 4-20 hours.

[0049] For example, the second mixture can be transferred into a 100 mL Teflon-lined autoclave and maintained at 140-220° C. for 10-20 hours.

[0050] As another example, ammonium molybdate and thiourea in a ratio of 1:2 to 1:6 can be completely dissolved in 50 mL of deionized water, added to the solution, and vigorously stirred for 30 minutes to obtain a first mixture.

[0051] In the present invention, during the contact between the thallium-containing flue gas and modified molybdenum disulfide, the mass ratio of the modified molybdenum disulfide to thallium monochloride in the thallium-containing flue gas is 2 to 10:1, and the thallium monochloride concentration in the thallium-containing flue gas is 0 to 5 mg / L. In more specific embodiments, the TlCl concentration in the thallium-containing flue gas can be 0.5 to 5 mg / L. It should be noted that the "thallium concentration" in the present invention refers to the thallium chloride concentration, and the same applies hereinafter.

[0052] In some embodiments of the present invention, when the flow rate of thallium-containing flue gas is 0.5-3 L / min, the amount of modified molybdenum disulfide used may be 50 mg, and the contact time between modified molybdenum disulfide and thallium-containing flue gas may be 30-120 min.

[0053] In the present invention, the temperature of the thallium-containing flue gas is 150-350° C. In some specific embodiments, the temperature of the thallium-containing flue gas may be 190-260° C.

[0054] In some embodiments of the present invention, when the modified molybdenum disulfide is DMF-intercalated molybdenum disulfide, the temperature of the thallium-containing flue gas is 220-260°C. In a flue gas environment where the background atmosphere of the thallium-containing flue gas is pure nitrogen, the thallium concentration is 0.5-5 mg / L, and the thallium-containing flue gas temperature is 220-260°C, the adsorption capacity of the DMF-intercalated molybdenum disulfide within 60 minutes is 100-159 mg / g; in a flue gas environment where the background atmosphere of the thallium-containing flue gas is pure nitrogen, the thallium concentration is 0.5-5 mg / L, and the thallium-containing flue gas temperature is 250°C, the adsorption capacity of the DMF-intercalated molybdenum disulfide within 60 minutes is 159 mg / g. In a flue gas environment where the background atmosphere of thallium-containing flue gas is a nitrogen atmosphere mixed with oxygen with a volume fraction of 4-8%, the thallium concentration is 0.5-5 mg / L, and the temperature of the thallium-containing flue gas is 250°C, the adsorption capacity of DMF-intercalated molybdenum disulfide within 60 minutes is 140-180 mg / g.

[0055] In some embodiments of the present invention, when the modified molybdenum disulfide is hydrothermal molybdenum disulfide, the temperature of the thallium-containing flue gas is 190-220°C. In a flue gas environment where the background atmosphere of the thallium-containing flue gas is pure nitrogen, the thallium concentration is 0.5-5 mg / L, and the thallium-containing flue gas temperature is 190-220°C, the adsorption capacity of the hydrothermal molybdenum disulfide within 60 minutes is 90-110 mg / g; in a flue gas environment where the background atmosphere of the thallium-containing flue gas is pure nitrogen, the thallium concentration is 0.5-5 mg / L, and the thallium-containing flue gas temperature is 200°C, the adsorption capacity of the hydrothermal molybdenum disulfide within 60 minutes is 110 mg / g. In a flue gas environment where the background atmosphere of thallium-containing flue gas is a nitrogen atmosphere mixed with oxygen with a volume fraction of 4-8%, the thallium concentration is 0.5-5 mg / L, and the temperature of the thallium-containing flue gas is 200°C, the adsorption capacity of hydrothermal molybdenum disulfide within 60 minutes is 90-132 mg / g.

[0056] In the present invention, the interlayer spacing of hydrothermal molybdenum disulfide is Typical graphite sheet structure; the interlayer spacing between two adjacent layers of DMF intercalated MoS2 nanosheets is The DMF-intercalated molybdenum disulfide is a two-dimensional nanosheet structure, and the DMF-intercalated molybdenum disulfide includes stacked molybdenum disulfide nanosheets and dimethylformamide inserted between two adjacent layers of molybdenum disulfide nanosheets.

[0057] In the present invention, the composition of the thallium-containing flue gas also includes oxygen and / or hydrogen chloride. When the thallium-containing flue gas includes oxygen, the volume proportion of oxygen in the thallium-containing flue gas is not higher than 20% by volume; when the thallium-containing flue gas includes hydrogen chloride, the volume proportion of hydrogen chloride in the thallium-containing flue gas is not higher than 20% by volume.

[0058] In some more specific embodiments of the present invention, when the thallium-containing flue gas includes oxygen, the volume fraction of oxygen in the thallium-containing flue gas is 4 to 8% by volume; when the thallium-containing flue gas includes hydrogen chloride, the volume fraction of hydrogen chloride in the thallium-containing flue gas is 4 to 8% by volume.

[0059] In the present invention, the thallium-containing flue gas includes sulfur dioxide, and the volume proportion of the sulfur dioxide in the thallium-containing flue gas is not higher than 20%.

[0060] In some more specific embodiments of the present invention, the volume proportion of the sulfur dioxide in the thallium-containing flue gas is 4-8%. Exemplarily, the volume proportion of the sulfur dioxide in the thallium-containing flue gas is 6%.

[0061] The present invention also provides a modified molybdenum disulfide, which is used in any of the above methods for treating thallium-containing flue gas.

[0062] In order to facilitate those skilled in the art to further understand the present invention, examples are given below:

[0063] Example 1

[0064] Preparation of DMF intercalated molybdenum disulfide:

[0065] The molybdenum from ammonium heptamolybdate and the sulfur from thiourea were completely dissolved in 50 mL of DMF at a molar ratio of 1:2 and added to the solution. The mixture was stirred vigorously for 30 minutes to obtain a first mixed solution. The first mixed solution was then transferred to a 100 mL Teflon-lined autoclave and maintained at 190°C for 15 hours. After centrifugation, a black precipitate (denoted as DMF-MoS2) was obtained. The product was then washed with deionized water and ethanol and dried at 80°C for 8 hours to obtain DMF-intercalated molybdenum disulfide.

[0066] Preparation of hydrothermal molybdenum disulfide:

[0067] The molybdenum from ammonium heptamolybdate and the sulfur from thiourea were completely dissolved in 50 mL of deionized water at a molar ratio of 1:2 and stirred vigorously for 30 minutes to obtain a second mixed solution. This second mixed solution was then transferred to a 100 mL Teflon-lined autoclave and maintained at 190°C for 15 hours. After centrifugation, a black precipitate (referred to as hydrothermal MoS2) was obtained. This was then washed with deionized water and ethanol, and finally dried at 80°C for 8 hours to obtain hydrothermal molybdenum disulfide.

[0068] Analysis example 1

[0069] The DMF-intercalated molybdenum disulfide, hydrothermal molybdenum disulfide and industrial molybdenum disulfide prepared in Example 1 were obtained.

[0070] XRD analysis

[0071] The phase structures of the modified molybdenum disulfide and industrial molybdenum disulfide were analyzed by XRD. Figure 1 As shown, the XRD diffraction pattern of industrial MoS2 matches well with the characteristic peak of 2H phase MoS2 (JCPDS PDF 77-1716), and the (002) crystal plane diffraction peak is located at 14.5°. According to the crystal Bragg equation (d = 0.5λ / sinθ), the interlayer spacing of industrial MoS2 is The XRD diffraction peak of the hydrothermal MoS2(002) surface is at 13.5°, and the corresponding interlayer spacing reaches The (001) diffraction peak in the XRD pattern of DMF-MoS2 moves to 8.9°, corresponding to a larger interlayer spacing. XRD analysis of the phase structure shows that compared to industrial MoS2, the phase structure of hydrothermal MoS2 and DMF-MoS2 has undergone a transformation, forming a two-dimensional layered structure with a larger interlayer spacing. Compared with industrial MoS2 and hydrothermal MoS2, DMF-MoS2 has a larger interlayer spacing and more crystal structure transformations.

[0072] EPR analysis

[0073] like Figure 2 As shown, EPR spectroscopy analysis reveals a gradually increasing trend in the intensity of the S defect signal across different MoS2 samples, confirming the presence of sulfur vacancies. In-depth analysis of the EPR signals across the different samples reveals that the sulfur vacancy content follows a pattern: DMF-MoS2 > hydrothermal MoS2 > industrial MoS2. The presence of sulfur vacancies significantly influences the coordination relationship between Mo and S on the MoS2 surface. The DMF-MoS2 sample, with the highest sulfur vacancy content, exhibits significantly superior performance in adsorption reactions, demonstrating significant advantages in adsorption capacity, catalytic performance, and material stability.

[0074] SEM, TEM, and HR-TEM analysis

[0075] like Figure 3 To investigate the microstructures of different MoS2 materials, SEM, TEM, and HR-TEM were used to analyze the microstructures of hydrothermal MoS2 and DMF-MoS2. As shown in the figure, SEM and TEM images reveal that both MoS2 materials possess a typical graphite lamellar structure, with distinct wavy boundaries on the surface. HR-TEM images reveal significant fractures in the interlayer structures of both hydrothermal MoS2 and DMF-MoS2, forming abundant boundary surfaces. These defect structures are beneficial in providing more active unsaturated sites, significantly increasing the adsorption activity of the material surface.

[0076] Example 2

[0077] Study on the Adsorption Performance of Thallium in Pure N2 Atmosphere

[0078] Intercalated molybdenum disulfide, hydrothermal molybdenum disulfide, and industrial molybdenum disulfide prepared in Example 1 were obtained, and their thallium adsorption performance under a pure N2 atmosphere was studied. Under a pure N2 atmosphere, the thallium concentration in the thallium-containing flue gas was controlled to be 0.5-5 mg / L, and the mass ratio of modified molybdenum disulfide or industrial molybdenum disulfide to thallium monochloride in the thallium-containing flue gas was 4:1. The removal performance of hydrothermal MoS2 and DMF-MoS2 was studied separately, as shown in Figure 4, where Figure 4(a) is a bar graph of the thallium adsorption capacity of hydrothermal molybdenum disulfide at different temperatures, and Figure 4(b) is a bar graph of the thallium adsorption capacity of DMF-intercalated molybdenum disulfide at different temperatures. The experimental results show that as the reaction temperature increases, the TlCl adsorption capacity of both MoS2 materials shows a trend of first increasing and then decreasing. Among them, hydrothermal MoS2 exhibits optimal thallium removal performance at a flue gas temperature of 200°C, reaching an adsorption capacity of >100 mg / g within 60 minutes; while DMF-MoS2 reaches its best thallium removal effect at a flue gas temperature of 250°C, reaching an adsorption capacity of 159 mg / g within 60 minutes. Compared with hydrothermal MoS2, DMF-MoS2 not only has superior thallium removal performance but also exhibits better thermal stability. In addition, both materials demonstrate good thallium removal performance at high temperatures of 200°C and 250°C, making them suitable for high-temperature smelting environments in the nonferrous industry.

[0079] In comparison, the adsorption capacity of industrial MoS2 within 60 minutes is 40 mg / g when the flue gas temperature is 200°C; and the adsorption capacity within 60 minutes is 7 mg / g when the flue gas temperature is 250°C.

[0080] Example 3

[0081] Study on the Adsorption Performance of Thallium under Different Atmospheres

[0082] The intercalated molybdenum disulfide and hydrothermal molybdenum disulfide prepared in Example 1 were obtained and their thallium adsorption performance under different atmospheres was studied (the thallium concentration under different atmosphere conditions was 0.5-5 mg / L, and the mass ratio of modified molybdenum disulfide to thallium monochloride in thallium-containing flue gas was 4:1). As shown in Figure 5, Figure 5(a) is a bar graph of the thallium adsorption capacity of hydrothermal molybdenum disulfide under different atmospheres at a flue gas temperature of 200°C, and Figure 5(b) is a bar graph of the thallium adsorption capacity of DMF-intercalated molybdenum disulfide under different atmospheres at a flue gas temperature of 250°C. Compared to tests conducted under a pure N2 atmosphere, the thallium adsorption capacities of hydrothermal MoS2 and DMF-MoS2 increased to a certain extent when 6% O2, H2O, and HCl gases were introduced into the N2 atmosphere individually. O2 significantly enhanced the thallium removal capacity of the adsorbent, increasing it by approximately 20 mg / g. The thallium adsorption capacity also increased to a certain extent when H2O and HCl gases were introduced into the N2 atmosphere. The introduction of 6% O2, H2O, and HCl gases into the N2 atmosphere alone promoted the adsorption of TlCl by MoS2, increasing the thallium adsorption capacities of hydrothermal MoS2 and DMF-MoS2 to a certain extent. Compared to tests conducted under other atmospheres, the introduction of 6% SO2 into the N2 atmosphere alone decreased the thallium adsorption capacities of both hydrothermal MoS2 and DMF-MoS2 to a certain extent. However, the inhibitory effect on TlCl adsorption by MoS2 was relatively weak, indicating that the adsorbents still exhibited excellent resistance to SO2 poisoning.

[0083] The effects of a complex atmosphere on the adsorption of TlCl by hydrothermal MoS2 and MoS2-DMF were also investigated. The TlCl adsorption performance of hydrothermal MoS2 and MoS2-DMF remained unchanged under complex atmospheres, demonstrating that hydrothermal MoS2 and MoS2-DMF are advantageous for achieving high TlCl removal performance under harsh conditions. The complex atmosphere composition, by volume, included 6% SO2, 6% O2, 6% H2O, and 1200 ppm HCl.

[0084] The above technical solutions of the present invention are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for treating thallium-containing flue gas, characterized in that: include: The thallium-containing flue gas contacts with modified molybdenum disulfide, and the modified molybdenum disulfide adsorbs TlCl in the thallium-containing flue gas; The modified molybdenum disulfide is hydrothermal molybdenum disulfide and / or DMF intercalated molybdenum disulfide; Wherein, the preparation of the DMF intercalated molybdenum disulfide comprises the steps of: Mixing a molybdenum-containing reagent, a sulfur-containing reagent, and dimethylformamide to obtain a first mixed solution; subjecting the first mixed solution to a high-temperature pressure treatment at 120 to 260° C. for 4 to 20 hours, and performing solid-liquid separation to obtain the DMF-expanded molybdenum disulfide layer; Wherein, the preparation of the hydrothermal molybdenum disulfide comprises the steps of: A molybdenum-containing reagent, a sulfur-containing reagent and deionized water are mixed to obtain a second mixed solution; the second mixed solution is subjected to a high-temperature pressure treatment at 120 to 260° C. for 4 to 20 hours, and solid-liquid separation is performed to obtain the DMF-extended layer of molybdenum disulfide.

2. The method for treating thallium-containing flue gas according to claim 1, characterized in that: During the contact between the thallium-containing flue gas and modified molybdenum disulfide, the mass ratio of the modified molybdenum disulfide to thallium monochloride in the thallium-containing flue gas is 2-10:1, and the concentration of thallium monochloride in the thallium-containing flue gas is 0-5 mg / L.

3. The method for treating thallium-containing flue gas according to claim 1, characterized in that: The temperature of the thallium-containing flue gas is 150-350°C.

4. The method for treating thallium-containing flue gas according to claim 3, characterized in that: When the modified molybdenum disulfide is DMF-intercalated molybdenum disulfide, the temperature of the thallium-containing flue gas is 220-260°C.

5. The method for treating thallium-containing flue gas according to claim 4, characterized in that: When the modified molybdenum disulfide is hydrothermal molybdenum disulfide, the temperature of the thallium-containing flue gas is 190-220°C.

6. The method for treating thallium-containing flue gas according to claim 1, characterized in that: The composition of the thallium-containing flue gas also includes oxygen and / or hydrogen chloride. When the thallium-containing flue gas includes oxygen, the volume proportion of oxygen in the thallium-containing flue gas is not higher than 20% by volume; when the thallium-containing flue gas includes hydrogen chloride, the concentration of hydrogen chloride in the thallium-containing flue gas is not higher than 5000 ppm by volume.

7. The method for treating thallium-containing flue gas according to claim 6, characterized in that: The thallium-containing flue gas includes sulfur dioxide, and the volume proportion of the sulfur dioxide in the thallium-containing flue gas is no more than 20%.

8. The method for treating thallium-containing flue gas according to claim 1, characterized in that: The flow rate of the thallium-containing flue gas is 0.5 to 3 L / min.

9. The method for treating thallium-containing flue gas according to claim 1, characterized in that: In the preparation of the DMF-intercalated molybdenum disulfide, the mass volume ratio of the molybdenum-containing reagent to the dimethylformamide is 1g:10-30ml; in the preparation of the hydrothermal molybdenum disulfide, the mass volume ratio of the molybdenum-containing reagent to the deionized water is 1g:10-30ml.

10. The method for treating thallium-containing flue gas according to claim 1, characterized in that: The molybdenum-containing reagent includes molybdenum element, the sulfur-containing reagent includes sulfur element, and the molar ratio of the molybdenum element to the sulfur element is 1:2-9.

Images