A spent lithium battery pyrolysis tail gas purification agent, a preparation method and application thereof

Abstract

The application discloses a waste lithium battery pyrolysis tail gas purifying agent and a preparation method and application thereof. The waste lithium battery pyrolysis tail gas purifying agent comprises a salt compound, a clay mineral and sodium alkyl benzene sulfonate, the salt compound comprises a calcium salt or a magnesium salt, and the content of each component in the purifying agent is as follows in mass: the salt compound is 20-75%, the clay mineral is 20-60%, and the sodium alkyl benzene sulfonate is 5-20%. By adjusting the use amount and the ratio of each component in the purifying agent, the volatile organic compounds such as carbonates, hydrocarbons and alcohols in the waste lithium battery pyrolysis tail gas can be effectively removed, the acidic fluorine phosphorus gas can be removed, the purpose of short-range treatment of the pyrolysis tail gas is achieved, the purifying effect of the purifying agent on the pyrolysis tail gas is good, the preparation method is simple, and the compounding raw materials required for preparing the purifying agent are cheap and easy to obtain.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste battery treatment and resource utilization, and particularly relates to a waste lithium battery pyrolysis tail gas purification agent, a preparation method and application thereof. BACKGROUND

[0002] The existing waste lithium battery recycling process mainly includes battery pack disassembly, cell discharge, crushing, pyrolysis, sorting and other procedures. The battery is pretreated to obtain black powder (a mixture of positive and negative electrode powders) and valuable materials such as copper powder and aluminum powder. The main role of pyrolysis is to remove the binder polymer in the pole piece, promote the pole powder to fall off from the aluminum foil, and facilitate the efficient sorting and recycling of the black powder. In the pyrolysis process, the solvent in the carbonate electrolyte first volatilizes and escapes, the lithium salt and additives in the lithium hexafluorophosphate electrolyte decompose to form volatile gases containing fluorine and phosphorus, and the remaining organic matter cracks to form various organic compounds such as hydrocarbons and alcohols. The tail gas formed in the pyrolysis process has many types of organic matter, large differences in material properties, and also contains volatile gases such as fluorine and phosphorus, so the tail gas treatment technology is difficult. SUMMARY

[0003] The inventors found that the purification of the waste lithium battery pyrolysis tail gas adopts a segmented treatment method, for example, the solvent in the electrolyte is removed by heating-condensation, the hydrocarbons are removed by burning the tail gas generated in the pyrolysis treatment, and the acidic fluorine and phosphorus gases are removed by spraying the absorption liquid. The waste lithium battery pyrolysis tail gas purification process is long, and the equipment process is complex.

[0004] The present application provides a waste lithium battery pyrolysis tail gas purification agent, a preparation method and application thereof, which can solve the problem of difficult treatment of the tail gas generated in the waste lithium battery pyrolysis treatment.

[0005] In a first aspect, the present application provides a waste lithium battery pyrolysis tail gas purification agent, which comprises a salt compound, a clay mineral and sodium alkyl benzene sulfonate, and the salt compound comprises a calcium salt or a magnesium salt.

[0006] The content of each component of the purification agent is as follows in mass:

[0007] The salt compound is 20% to 75%;

[0008] The clay mineral is 20% to 60%;

[0009] The sodium alkyl benzene sulfonate is 5% to 20%.

[0010] In some embodiments, the content of each component of the purification agent is as follows in mass:

[0011] The salt compound is 40% to 60%;

[0012] clay mineral 20%~40%;

[0013] sodium alkyl benzene sulfonate 10%~15%.

[0014] In some embodiments, the calcium salt comprises at least one of calcium hydroxide, calcium oxide.

[0015] In some embodiments, the magnesium salt comprises at least one of magnesium hydroxide, magnesium oxide.

[0016] In some embodiments, the clay mineral comprises at least one of montmorillonite, kaolinite.

[0017] In some embodiments, the particle size of the salt compound is R, R satisfies: 25 pm≤R≤75 pm.

[0018] In some embodiments, the purification agent has a pore structure;

[0019] The specific surface area of the purification agent is β, 20 m 2 / g≤β≤50 m 2 / g.

[0020] The average pore size of the pore structure of the purification agent is r, 2 nm≤r≤8 nm.

[0021] In a second aspect, the present application provides a preparation method of a waste lithium battery pyrolysis tail gas purification agent, comprising:

[0022] providing a compound raw material, the compound raw material comprising a mixed uniform salt compound, clay mineral and sodium alkyl benzene sulfonate, the salt compound comprising a calcium salt or a magnesium salt;

[0023] The content of each component of the compound raw material is, by mass:

[0024] salt compound 20%~75%;

[0025] clay mineral 20%~60%;

[0026] sodium alkyl benzene sulfonate 5%~20%;

[0027] The compound raw material is mixed with water by mixing treatment to be uniformly mixed, and is subjected to molding treatment and drying treatment to obtain a waste lithium battery pyrolysis tail gas purification agent.

[0028] In some embodiments, the mixing treatment comprises: uniformly mixing water and the compound raw material according to a weight ratio of 0.1~0.5:1;

[0029] The drying temperature of the drying treatment is T, T satisfies: 100℃≤T≤200℃.

[0030] In a third aspect, the application provides application of a waste lithium battery pyrolysis tail gas purifying agent in waste lithium battery pyrolysis treatment, wherein the waste lithium battery pyrolysis tail gas purifying agent is used for adsorbing at least one of volatile organic compounds, acidic fluorophosphorus gas generated in the pyrolysis treatment.

[0031] The volatile organic compounds include at least one of carbonate organic compounds, hydrocarbon organic compounds, and alcohol organic compounds.

[0032] The waste lithium battery includes at least one of ternary lithium batteries and lithium iron phosphate batteries.

[0033] The waste lithium battery pyrolysis tail gas purifying agent, the preparation method and the application thereof provided by the application are prepared by compounding the three substances of salt compounds, clay minerals and sodium alkyl benzene sulfonate. The clay minerals can be fused with water to facilitate the molding of the purifying agent in the preparation process, fix the position of the salt compounds in the purifying agent, and form a purifying agent with a pore structure after removing water in the preparation process of the purifying agent, so that the purifying agent can adsorb gas. In addition, the clay minerals themselves have good adsorption effect on gas, which can effectively remove volatile organic gases such as alcohols, carbonates and hydrocarbons in the tail gas. The clay minerals can also react with acidic fluorophosphorus gas. Sodium alkyl benzene sulfonate has good lipophilicity, which is conducive to the removal of low-boiling-point organic matters such as carbonates. Sodium alkyl benzene sulfonate has good dispersion effect. After adding water in the preparation process of the purifying agent, sodium alkyl benzene sulfonate helps to promote the uniform dispersion and molding of the three substances of salt compounds, clay minerals and sodium alkyl benzene sulfonate, so that a uniformly distributed purifying agent is obtained after drying and removing water. As for the salt compounds, calcium salt and magnesium salt that can react with acidic fluorophosphorus gas are selected to remove acidic fluorophosphorus gas in the tail gas, and water-insoluble salt compounds are selected so that the salt compounds can exist in a granular state, and the selected salt compounds have a certain adsorption effect and can adsorb the tail gas generated in the pyrolysis process, so that the tail gas can be more fully contacted with the purifying agent.

[0034] The application can effectively remove carbonate, hydrocarbon, alcohol and other volatile organic compounds in waste lithium battery pyrolysis tail gas and remove acidic fluorophosphorus gas by adjusting the amount and ratio of each component of the purifying agent, so as to realize the purpose of short-path treatment of pyrolysis tail gas. The purifying effect of the purifying agent in treating pyrolysis tail gas is good, the preparation method is simple, and the compounding raw materials required for preparing the purifying agent are cheap and easy to obtain. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only constitute some embodiments of the present application, and other accompanying drawings can be obtained by those skilled in the art without any creative effort.

[0036] Figure 1 A physical map of the waste lithium battery pyrolysis tail gas purification agent obtained in Embodiment 1;

[0037] Figure 2 A desorption isotherm curve of the waste lithium battery pyrolysis tail gas purification agent obtained in Embodiment 1. DETAILED DESCRIPTION

[0038] In order to make the purposes, technical solutions and advantages of the present application more clear, the present application will be further described in detail below in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0039] The inventors found that in the related art, the waste lithium battery pyrolysis tail gas is purified by using a segmented treatment method, such as removing the solvent of the electrolyte by heating-condensing, removing the hydrocarbons by burning the tail gas generated by pyrolysis treatment, and removing the acidic fluorophosphorus gas by spraying the absorption liquid. The waste lithium battery pyrolysis tail gas purification process is relatively long, and the equipment process is complex. The present application provides a waste lithium battery pyrolysis tail gas purification agent and a preparation method and application thereof, which can solve the problem of difficult treatment of the tail gas generated by waste lithium battery pyrolysis treatment.

[0040] The waste lithium battery pyrolysis tail gas purification agent provided by the present application is used for treating the tail gas generated by waste lithium battery pyrolysis treatment. The tail gas generated by pyrolysis treatment includes volatile organic compounds such as carbonates, hydrocarbons, alcohols, and acidic fluorophosphorus gas.

[0041] The purification agent includes a salt compound, a clay mineral and sodium alkyl benzene sulfonate, and the salt compound includes a calcium salt or a magnesium salt. The content of each component of the purification agent is as follows in terms of mass:

[0042] The salt compound is 20% to 75%;

[0043] The clay mineral is 20% to 60%;

[0044] The sodium alkyl benzene sulfonate is 5% to 20%.

[0045] The three substances are compounded to obtain the purifying agent, wherein the clay mineral can be mixed with water to facilitate the molding of the purifying agent in the preparation process, fix the position of the salt compound in the purifying agent, and form the purifying agent with a pore structure after the water is removed in the preparation process of the purifying agent, so that the purifying agent can adsorb the gas. In addition, the clay mineral itself has a good adsorption effect on the gas, and can effectively remove volatile organic gases such as alcohols, carbonates and hydrocarbons in the tail gas. The clay mineral can also react with acidic fluorophosphorus gas. The alkyl benzene sulfonate has good lipophilicity, which is conducive to the removal of low-boiling-point organic matter such as carbonates. The alkyl benzene sulfonate has good dispersion effect. After water is added in the preparation process of the purifying agent, the alkyl benzene sulfonate helps to promote the uniform dispersion and molding of the three substances, so that the purifying agent with uniform distribution can be obtained after drying and removing water.

[0046] As for the salt compound, calcium salt and magnesium salt that can react with acidic fluorophosphorus gas are selected to remove the acidic fluorophosphorus gas in the tail gas. The salt compound that is insoluble in water is selected so that the salt compound can exist in a granular state. The selected salt compound has a certain adsorption effect and can adsorb the tail gas generated in the pyrolysis process, so that the tail gas can be more fully contacted with the purifying agent.

[0047] The application can effectively remove volatile organic compounds such as alcohols, carbonates and hydrocarbons in the pyrolysis tail gas of waste lithium batteries and acidic fluorophosphorus gas at the same time by adjusting the amount and ratio of each component of the purifying agent. The purpose of short-range treatment of the pyrolysis tail gas is achieved. The purifying effect of the purifying agent on the pyrolysis tail gas is good, the preparation method is simple, and the compounding raw materials required for preparing the purifying agent are cheap and easy to obtain.

[0048] Preferably, the content of each component of the purifying agent is as follows in terms of mass:

[0049] The salt compound is 40% to 60%;

[0050] The clay mineral is 20% to 40%;

[0051] The alkyl benzene sulfonate is 10% to 15%.

[0052] By further optimizing the amount and ratio of the three substances, i.e. the salt compound, the clay mineral and the alkyl benzene sulfonate, the removal rate of volatile organic compounds such as alcohols, carbonates and hydrocarbons in the pyrolysis tail gas of waste lithium batteries and acidic fluorophosphorus gas can be higher.

[0053] In some embodiments, the calcium salt includes at least one of calcium hydroxide and calcium oxide.

[0054] In some embodiments, the magnesium salt includes at least one of magnesium hydroxide, magnesium oxide.

[0055] In some embodiments, the clay mineral includes at least one of montmorillonite, kaolinite.

[0056] In some embodiments, the purification agent is selected from a water-insoluble salt compound, so that the salt compound can maintain its form during the preparation of the purification agent, and thus the salt compound can adsorb the pyrolysis tail gas in the obtained purification agent, and the acidic fluorine phosphorus gas can enter the interior of the purification agent and react with the salt compound to be consumed. The salt compound is in a particulate form, and the particle size of the salt compound is R, which satisfies 25 pm≤R≤75 pm, for example, R can be 25 pm, 45 pm, 55 pm, 65 pm, 75 pm, or any range in the above two. By selecting the particle size R of the salt compound particles in the above range, the salt compound can be more uniformly distributed in the purification agent, preventing the salt compound particles from being too large and unevenly distributed during the preparation process. At the same time, the salt compound has a suitable specific surface area to better adsorb the tail gas generated by the pyrolysis of the waste lithium battery.

[0057] In some embodiments, the purification agent has a pore structure, so that the purification agent can adsorb the tail gas generated by the pyrolysis of the waste lithium battery. The pyrolysis-generated tail gas can enter the space of the pore structure to contact the salt compound, the clay mineral, and sodium alkylbenzenesulfonate, respectively, so as to correspondingly adsorb the volatile organic compounds such as carbonates, hydrocarbons, and alcohols in the waste lithium battery pyrolysis tail gas, and react with the acidic fluorine phosphorus gas.

[0058] In some embodiments, the specific surface area of the purification agent is β, and 20 m 2 / g≤β≤50 m 2 / g, for example, β can be 20 m 2 / g, 25 m 2 / g, 30 m 2 / g, 40 m 2 / g, 50 m 2 / g, or any range in the above two. By selecting the specific surface area β of the purification agent in the above range, the purification agent has a suitable specific surface area, so as to more fully absorb the pyrolysis-generated tail gas. When β is higher than 50 m 2 / g, the specific surface area of the purification agent is too large, and the prepared purification agent is too loose, which results in poor interception effect on the gas, thereby leading to poor adsorption effect on the pyrolysis tail gas, and in addition, it is also easy to cause poor structural strength and easy to break of the purification agent. When β is lower than 20 m 2 / g, the specific surface area of the purification agent is too small, and the pyrolysis-generated tail gas is difficult to enter the interior of the purification agent, resulting in poor adsorption effect on the pyrolysis-generated tail gas.

[0059] In some embodiments, the average pore size of the pore structure of the purification agent is r, 2nm≤r≤8nm, for example, r can be 2nm, 3nm, 5nm, 7nm, 8nm or any range between any of the above. By selecting the average pore size of the pore structure of the purification agent in the above range, it is convenient for the pyrolysis tail gas to enter the space of the pore structure, improve the contact efficiency of the pyrolysis tail gas and the purification agent, and the purification agent can more efficiently adsorb the gas in the pyrolysis tail gas. When r is higher than 8nm, the average pore size is too large, the specific surface area of the purification agent is too small, the contact rate with the pyrolysis tail gas is low, the purification effect on the tail gas is poor, and in addition, it is also easy to cause the structure of the purification agent to collapse. When r is higher than 2nm, the average pore size is too small, the pyrolysis tail gas is difficult to enter the inside of the purification agent, and the adsorption effect of the purification agent is poor.

[0060] The application also provides a preparation method of the waste lithium battery pyrolysis tail gas purification agent, for preparing the waste lithium battery pyrolysis tail gas purification agent as described above. The preparation method of the purification agent comprises:

[0061] The compounding raw material comprises uniformly mixed salt compounds, clay minerals and sodium alkyl benzene sulfonate, and the salt compounds comprise calcium salt or magnesium salt.

[0062] The content of each component of the compounding raw material is as follows in terms of mass:

[0063] The salt compound is 20%~75%;

[0064] The clay mineral is 20%~60%;

[0065] The sodium alkyl benzene sulfonate is 5%~20%;

[0066] The compounding raw material is mixed uniformly with water through mixing treatment, and is obtained through molding treatment and drying treatment to obtain the waste lithium battery pyrolysis tail gas purification agent.

[0067] In the compounding raw material of the application, the salt compounds are in granular form, the clay minerals and the sodium alkyl benzene sulfonate are in powder form, and the salt compounds, the clay minerals and the sodium alkyl benzene sulfonate are mixed to obtain the compounding raw material. In the mixing treatment, the water is mixed with the compounding raw material, the water infiltrates the clay minerals, the clay minerals have viscosity, and through stirring, the salt compounds, the clay minerals and the sodium alkyl benzene sulfonate are mixed uniformly, the salt compounds are prevented from settling, the sodium alkyl benzene sulfonate has good dispersion effect, the salt compounds are facilitated to contact with the clay minerals, and thus the salt compounds, the clay minerals and the sodium alkyl benzene sulfonate are mixed more uniformly.

[0068] In some embodiments, the mixing treatment comprises: mixing the water and the compound raw material uniformly according to a weight ratio of 0.1-0.5:1, for example, the mixing treatment can be performed according to 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1 or any range between any two of the above. In the above range of the weight ratio of the water and the compound raw material, the clay mineral has a suitable viscosity after being soaked by the water, so that the clay mineral can better adhere to the salt compound, so that the salt compound, the clay mineral and the sodium alkyl benzene sulfonate are mixed more uniformly, and the viscosity of the mixture of the compound raw material and the water is also suitable, so that the subsequent forming treatment is facilitated.

[0069] The compound raw material and the water are subjected to the mixing treatment, and then the mixture of the compound raw material and the water is subjected to a forming treatment to obtain mixed wet material. The forming treatment can be performed by granulation, extrusion or the like to obtain mixed wet material in the form of a ball, a strip, a sheet or a honeycomb. After the forming treatment, the mixed wet material is subjected to a drying treatment to obtain the waste lithium battery pyrolysis tail gas purifying agent. As shown in FIG. 2, the waste lithium battery pyrolysis tail gas purifying agent obtained after the drying treatment in an embodiment of the present application is in the form of a strip. Figure 1

[0070] In some embodiments, the drying temperature of the drying treatment is T, and T satisfies 100°C≤T≤200°C, for example, T can be 100°C, 150°C, 100°C, 180°C, 200°C or any range between any two of the above. By selecting the temperature T of the drying treatment in the above range, the temperature is suitable, so that the water in the mixed wet material can be effectively removed, while the salt compound, the clay mineral and the sodium alkyl benzene sulfonate are prevented from being damaged by the temperature, and the mixed wet material can be easily formed and have a pore structure.

[0071] The waste lithium battery pyrolysis tail gas purifying agent in the embodiments of the present application can be applied in waste lithium battery pyrolysis treatment. The principle of the waste lithium battery pyrolysis treatment is to utilize the thermal instability of the organic matter in the solid waste of the waste lithium battery, heat in an oxygen-deficient environment in a pyrolysis reactor, so that the organic matter is subjected to thermal chemical decomposition to generate gas, oil and carbon black and the like. This technology can effectively decompose the organic matter in the battery through high-temperature treatment, so that the components of the battery are dissociated from each other, and the subsequent resource recovery is facilitated.

[0072] The waste lithium battery pyrolysis tail gas purifying agent in the embodiments of the present application is used for adsorbing at least one of volatile organic compounds and acidic fluorine phosphorus gas generated in the pyrolysis treatment. In some embodiments, the volatile organic compounds include at least one of alcohol, carbonate and hydrocarbon organic compounds. The carbonate organic compounds include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate and dimethyl carbonate, and the alcohol organic compounds include C2H6O2, C 10 H​22 O, C 11 H 24 O, C 18 H 38 At least one of O, and hydrocarbon organic compounds including C9H 18 C 12 H 24 C 12 H 16 C 18 H 36 At least one of the following. Fluoride-containing acidic gases include hydrogen fluoride, and phosphorus-containing gases include phosphorus oxyfluoride.

[0073] In some embodiments, the waste lithium batteries include at least one of ternary lithium batteries and lithium iron phosphate batteries.

[0074] The technical solution of this application is described below with reference to specific embodiments. The raw materials used in the following embodiments are all from commercially available products, and the devices or equipment used are all purchased from conventional market sales channels.

[0075] Example 1

[0076] Step S100: Mix 60g of calcium oxide, 30g of montmorillonite and 10g of sodium alkylbenzene sulfonate evenly to obtain a compound raw material, wherein the particle size of calcium oxide is 50μm.

[0077] Step S200: Mix water and compound raw materials evenly at a weight ratio of 0.4:1. Then, extrude the mixture of compound raw materials and water to form a round strip of wet material with a diameter of 5 mm.

[0078] Step S300: Dry the mixed wet material at 150°C for 1 hour to obtain a waste lithium battery pyrolysis tail gas purifier.

[0079] The BET method was used to detect the specific surface area β and the average pore size r of the pore structure of the purifying agent. For example... Figure 2 The figure shows the adsorption-desorption isotherm curves obtained by BET method for the purifying agent in this embodiment. According to the adsorption-desorption isotherm curves, the specific surface area β of the purifying agent for waste lithium battery pyrolysis tail gas in this embodiment is 29.2 m². 2 / g, the average pore size r of the pore structure is 5.4 nm.

[0080] The waste lithium battery pyrolysis tail gas purifier is used in the tail gas treatment device to treat the tail gas generated by the pyrolysis of waste ternary lithium batteries. The tail gas treatment temperature is 80℃ and the flow rate of the tail gas introduced in the tail gas treatment is 100mL / min.

[0081] In each of the embodiments and comparative examples, the content of the carbonate, alcohol, and hydrocarbon organic gas compounds is detected by a mass spectrometry method.

[0082] In each of the embodiments and comparative examples, the content of fluorine is obtained by an ion chromatography method after the gas is absorbed by a lye, and the content of phosphorus is obtained by an ICP (Inductively Coupled Plasma) method.

[0083] The removal rate of the gas = [ (the content of the gas before tail gas treatment - the content of the gas after tail gas treatment) / the content of the gas before tail gas treatment) 100%.

[0084] In this embodiment, the removal rate of the carbonate organic compound is 87.2%, the removal rate of the hydrocarbon organic compound is 81.5%, the removal rate of the alcohol organic compound is 89.9%, and the removal rate of the acidic fluorine phosphorus gas is 95.3%.

[0085] Embodiment 2

[0086] The difference from Embodiment 1 is that:

[0087] In step S100, 60 g of calcium hydroxide, 30 g of montmorillonite, and 10 g of sodium alkyl benzene sulfonate are uniformly mixed to obtain a compounded raw material, wherein the particle size of the calcium hydroxide is 50 μm.

[0088] In this embodiment, the removal rate of the carbonate organic compound is 85.7%, the removal rate of the hydrocarbon organic compound is 80.2%, the removal rate of the alcohol organic compound is 86.2%, and the removal rate of the acidic fluorine phosphorus gas is 94.6%.

[0089] Embodiment 3

[0090] The difference from Embodiment 1 is that:

[0091] In step S100, 50 g of calcium oxide, 35 g of montmorillonite, and 15 g of sodium alkyl benzene sulfonate are uniformly mixed to obtain a compounded raw material.

[0092] In this embodiment, the removal rate of the carbonate organic compound is 92.4%, the removal rate of the hydrocarbon organic compound is 83.7%, the removal rate of the alcohol organic compound is 90.8%, and the removal rate of the acidic fluorine phosphorus gas is 95.1%.

[0093] Embodiment 4

[0094] The difference from Embodiment 1 is that:

[0095] In step S100, 60 g of magnesium oxide, 30 g of montmorillonite and 10 g of sodium alkyl benzene sulfonate are uniformly mixed to obtain a compounded raw material. The particle size of the magnesium oxide is 50 μm.

[0096] In this embodiment, the removal rate of the carbonate organic compound is 77.3%, the removal rate of the hydrocarbon organic compound is 72.8%, the removal rate of the alcohol organic compound is 81.5%, and the removal rate of the acidic fluorine phosphorus gas is 87.9%.

[0097] Example 5

[0098] The difference from Example 1 is that:

[0099] In step S100, 60 g of magnesium oxide, 30 g of montmorillonite and 10 g of sodium alkyl benzene sulfonate are uniformly mixed to obtain a compounded raw material. The particle size of the magnesium oxide is 50 μm.

[0100] In this embodiment, the removal rate of the carbonate organic compound is 74.5%, the removal rate of the hydrocarbon organic compound is 70.4%, the removal rate of the alcohol organic compound is 77.4%, and the removal rate of the acidic fluorine phosphorus gas is 85.1%.

[0101] Example 6

[0102] The difference from Example 1 is that:

[0103] In step S100, 60 g of magnesium oxide, 30 g of montmorillonite and 10 g of sodium alkyl benzene sulfonate are uniformly mixed to obtain a compounded raw material. The particle size of the magnesium oxide is 50 μm.

[0104] In this embodiment, the removal rate of the carbonate organic compound is 80.1%, the removal rate of the hydrocarbon organic compound is 74.4%, the removal rate of the alcohol organic compound is 82.6%, and the removal rate of the acidic fluorine phosphorus gas is 86.2%.

[0105] Example 7

[0106] The difference from Example 1 is that:

[0107] In step S100, 60 g of magnesium oxide, 30 g of montmorillonite and 10 g of sodium alkyl benzene sulfonate are uniformly mixed to obtain a compounded raw material.

[0108] In this embodiment, the removal rate of the carbonate organic compound is 82.7%, the removal rate of the hydrocarbon organic compound is 76.7%, the removal rate of the alcohol organic compound is 83.9%, and the removal rate of the acidic fluorine phosphorus gas is 94.1%.

[0109] Comparative Example 1

[0110] The difference from Example 1 is that:

[0111] In step S100, 65 g of calcium oxide and 35 g of montmorillonite are mixed uniformly, wherein the particle size of the calcium oxide is 50 μm. In step S200, water is mixed with the mixture of the calcium oxide and the montmorillonite of step S100 uniformly at a weight ratio of 0.4:1.

[0112] In the present comparative example, the removal rate of the carbonate organic compound was 66.6%, the removal rate of the hydrocarbon organic compound was 63.4%, the removal rate of the alcohol organic compound was 69.3%, and the removal rate of the acidic fluorophosphorus gas was 95.9%.

[0113] Comparative Example 2

[0114] The difference from Example 1 is that:

[0115] In step S100, calcium oxide having a particle size of 50 μm is directly provided, and in step S200, water is directly mixed with the calcium oxide of step S100 uniformly at a weight ratio of 0.4:1.

[0116] In the present comparative example, the removal rate of the carbonate organic compound was 21.3%, the removal rate of the hydrocarbon organic compound was 19.2%, the removal rate of the alcohol organic compound was 29.7%, and the removal rate of the acidic fluorophosphorus gas was 95.5%.

[0117] Comparative Example 3

[0118] The difference from Example 1 is that:

[0119] In step S100, montmorillonite is directly provided, and in step S200, water is directly mixed with the montmorillonite of step S100 uniformly at a weight ratio of 0.4:1.

[0120] In the present comparative example, the removal rate of the carbonate organic compound was 44.4%, the removal rate of the hydrocarbon organic compound was 40.8%, the removal rate of the alcohol organic compound was 46.6%, and the removal rate of the acidic fluorophosphorus gas was 88.2%.

[0121] Comparative Example 4

[0122] The difference from Example 1 is that:

[0123] In step S100, 90 g of calcium oxide and 10 g of sodium alkylbenzenesulfonate are mixed uniformly, wherein the particle size of the calcium oxide is 50 μm. In step S200, water is mixed with the mixture of the calcium oxide and the sodium alkylbenzenesulfonate of step S100 uniformly at a weight ratio of 0.4:1.

[0124] In the comparative example, the removal rate of carbonate organic compounds is 50.9%, the removal rate of hydrocarbon organic compounds is 51.9%, the removal rate of alcohol organic compounds is 60.4%, and the removal rate of acidic fluorophosphorus gas is 95.0%.

[0125] Comparative Example 5

[0126] The difference from Example 1 is that:

[0127] In step S100, 90 g of montmorillonite and 10 g of sodium alkyl benzene sulfonate are uniformly mixed. In step S200, water is mixed with the mixture of montmorillonite and sodium alkyl benzene sulfonate in step S100 according to a weight ratio of 0.4:1.

[0128] In this example, the removal rate of carbonate organic compounds is 68.6%, the removal rate of hydrocarbon organic compounds is 67.2%, the removal rate of alcohol organic compounds is 73.5%, and the removal rate of acidic fluorophosphorus gas is 91.8%.

[0129] The relevant parameters and experimental results in Examples 1-7 and Comparative Examples 1-5 are shown in Table 1.

[0130] Table 1

[0131]

[0132] As can be seen from Examples 1-7 and Comparative Examples 1-5 in Table 1, only the purification agent prepared by compounding salt compounds, clay minerals and sodium alkyl benzene sulfonate can effectively remove ester, hydrocarbon, alcohol and other volatile organic compounds, and acidic fluorophosphorus gas in the pyrolysis tail gas of waste lithium batteries.

[0133] As can be seen from Example 1 and Comparative Example 1, only salt compounds and clay minerals are included in the purification agent, and due to the adsorption of salt compounds and clay minerals, although there is a certain adsorption effect on hydrocarbon and alcohol organic compounds, since there is no sodium alkyl benzene sulfonate, the mixing uniformity of salt compounds and clay minerals is poor, and the adsorption effect on ester is poor, resulting in poor overall removal effect of the purification agent on ester, hydrocarbon and alcohol organic compounds.

[0134] As can be seen from Comparative Examples 2 and 4, and Comparative Examples 3 and 5, adding sodium alkyl benzene sulfonate to only salt compounds or clay minerals can improve the removal effect of volatile organic compounds and acidic fluorophosphorus gas in the pyrolysis tail gas to some extent, but the removal effect is still poor.

[0135] It is to be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0136] Various embodiments are described herein with reference to particular applications with a specific configuration and contents for convenience. It is to be understood that the application is not limited to those embodiments but cover any technical equivalents in principle as far as they are within the scope of a patent protection. The same or similar parts or features in various embodiments are designated by the same reference numerals as far as possible, and each embodiment is described with a focus on the difference from other embodiments.

[0137] The above description is merely illustrative of the application and is not to be taken in a limiting sense. It is contemplated that departures from the specific design choices disclosed can still come within the scope of the application. Any modifications and equivalents are intended to be included within the scope of the application. Various specific details are given in the foregoing description to provide a thorough understanding of the application. However, the application can be practiced without these specific details. The scope of the application is indicated by the appended claims rather than the foregoing description.

Claims

1. A spent lithium battery pyrolysis tail gas purification agent, characterized in that, The purifying agent comprises a salt compound, clay minerals, and sodium alkylbenzene sulfonate, wherein the salt compound is at least one selected from calcium oxide, calcium hydroxide, magnesium oxide, and magnesium hydroxide; The content of each component in the purifying agent, by mass, is as follows: Salt compounds 20%~75%; Clay minerals: 20%–60%; Sodium alkylbenzene sulfonate 5%~20%. 2.The spent lithium battery pyrolysis tail gas purification agent according to claim 1, characterized in that, The content of each component in the purifying agent, by mass, is as follows: Salt compounds: 40%–60%; Clay minerals: 20%–40%; Sodium alkylbenzene sulfonate 10%~15%. 3.The spent lithium battery pyrolysis tail gas purification agent according to claim 1, characterized in that, The clay minerals include at least one of montmorillonite and kaolinite. 4.The spent lithium battery pyrolysis tail gas purification agent according to claim 1, characterized in that, The particle size of the salt compound is R, where R satisfies: 25μm≤R≤75μm.

5. The waste lithium battery pyrolysis tail gas purifier according to claim 1, characterized in that, The purifying agent has a porous structure; The specific surface area of the purifying agent is β, 20 m 2 / g ≤ β ≤ 50 m 2 / g; The average pore size of the pore structure of the purifying agent is r, where 2 nm ≤ r ≤ 8 nm.

6. A method for preparing a purifying agent for waste lithium battery pyrolysis tail gas, characterized in that, include: A compound raw material is provided, the compound raw material comprising a uniformly mixed salt compound, clay minerals and sodium alkylbenzene sulfonate, wherein the salt compound is at least one selected from calcium oxide, calcium hydroxide, magnesium oxide and magnesium hydroxide; The content of each component in the compound raw material, by mass, is as follows: Salt compounds 20%~75%; Clay minerals: 20%–60%; Sodium alkylbenzene sulfonate 5%~20%; The compound raw materials are mixed evenly with water, and then subjected to molding and drying processes to obtain a waste lithium battery pyrolysis tail gas purifier.

7. The preparation method according to claim 6, characterized in that, The mixing process includes: mixing water and the compound raw materials at a weight ratio of 0.1 to 0.5:1 until homogeneous; The drying temperature of the drying process is T, where T satisfies the following condition: 100℃≤T≤200℃.

8. The application of the waste lithium battery pyrolysis tail gas purifier according to any one of claims 1-5 in the pyrolysis treatment of waste lithium batteries, wherein the waste lithium battery pyrolysis tail gas purifier is used to adsorb at least one of the volatile organic compounds and acidic fluorine and phosphorus gases generated in the pyrolysis treatment. The volatile organic compounds include at least one of carbonate organic compounds, hydrocarbon organic compounds, and alcohol organic compounds; The waste lithium batteries include at least one of ternary lithium batteries and lithium iron phosphate batteries.

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