Adsorbent regeneration method

Abstract

The present invention discloses a regeneration method for an adsorbent, comprising: subjecting the adsorbent to be regenerated to treatment in a first atmosphere at a first temperature; subjecting the adsorbent treated at the first temperature to treatment in a second atmosphere at a second temperature; subjecting the adsorbent treated at the second temperature to treatment in a third atmosphere at a third temperature; wherein the first temperature is 70-180°C, the second temperature is 220-400°C, and the third temperature is 150-200°C; the first atmosphere comprises a nitrogen environment or a vacuum environment, the second atmosphere comprises a nitrogen environment or a vacuum environment, and the third atmosphere comprises an oxidizing atmosphere. The adsorbent regenerated by the above method can adsorb boron, phosphorus, and metal impurities in trichlorosilane, and the regenerated adsorbent has good adsorption effect and high adsorption efficiency, can be recycled, and reduces costs.

Description

Technical Field

[0001] The invention belongs to the technical field of adsorbents, and particularly relates to a regeneration method for an adsorbent. Background Art

[0002] The demand for the development of solar photovoltaic technology is becoming increasingly urgent, and the purity requirements for polysilicon raw materials are becoming increasingly higher. The purity of polysilicon depends largely on the purification of trichlorosilane. Currently, the main impurities in trichlorosilane include substances such as boron, phosphorus, and metals, which are important factors affecting the purity of polysilicon. Due to the disadvantages of high energy consumption and easy pollution caused by traditional distillation, the use of adsorption to remove trichlorosilane impurities is gaining increasing attention. Solid adsorbents are very pure and are particularly effective for impurity separation. However, the adsorbed impurities often poison the adsorbent or cause it to reach saturation, making it only a single use. Once saturated, it must be discarded and replaced. To recycle the adsorbent and reduce costs, the adsorbent can be regenerated. However, the regeneration process often simply desorbs the adsorbent and does not enhance the adsorption performance of the adsorbent. The adsorption effect of the regenerated adsorbent is poor. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide a method for regenerating an adsorbent, so as to solve the problem of poor adsorption effect of the regenerated adsorbent.

[0004] An embodiment of the present invention provides a method for regenerating an adsorbent, comprising:

[0005] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment;

[0006] placing the adsorbent treated at the first temperature in a second atmosphere for treatment at a second temperature;

[0007] placing the adsorbent treated at the second temperature at a third temperature and in a third atmosphere for treatment;

[0008] Wherein, the first temperature is 70-180°C, the second temperature is 220-400°C, and the third temperature is 150-200°C;

[0009] The first atmosphere environment includes a nitrogen environment or a vacuum environment, the second atmosphere environment includes a nitrogen environment or a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere.

[0010] Optionally, the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment includes:

[0011] The adsorbent to be regenerated is placed at a first temperature and in a first atmosphere for treatment for 6-36 hours.

[0012] Optionally, the step of placing the adsorbent treated at the first temperature in a second atmosphere for treatment includes:

[0013] The adsorbent treated at the first temperature is placed at a second temperature and in a second atmosphere for treatment for 16-48 hours.

[0014] Optionally, the second atmosphere is a vacuum environment, and the step of placing the adsorbent treated at the second temperature in a third atmosphere at a third temperature for treatment includes:

[0015] The adsorbent treated at the second temperature is placed at a third temperature and in a third atmosphere for treatment for 6-36 hours.

[0016] Optionally, after the step of placing the adsorbent treated at the second temperature in a third atmosphere for treatment, the method further comprises:

[0017] placing the adsorbent treated at the third temperature at a fourth temperature and in a fourth atmosphere for treatment for 1-2 hours;

[0018] The fourth temperature is 90-130° C., and the fourth atmosphere is an ammonia atmosphere.

[0019] Optionally, the third atmosphere includes ammonia.

[0020] Optionally, the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment includes:

[0021] placing the adsorbent to be regenerated in a first atmosphere, heating the temperature from room temperature to a first temperature at a first heating rate, and treating the adsorbent at the first temperature for 6-28 hours;

[0022] The first heating rate is 3-6°C / min;

[0023] Optionally, the step of placing the adsorbent treated at the first temperature in a second atmosphere for treatment includes:

[0024] placing the adsorbent treated at the first temperature in a second atmosphere, heating the adsorbent from the first temperature to the second temperature at a second heating rate, and treating the adsorbent at the second temperature for 8-36 hours;

[0025] The second heating rate is 4-10°C / min.

[0026] Optionally, the step of placing the adsorbent treated at the second temperature in a third atmosphere for treatment at a third temperature includes:

[0027] placing the adsorbent treated at the second temperature in a third atmosphere, cooling the adsorbent from the second temperature to a third temperature at a first cooling rate, and treating the adsorbent at the third temperature for 6-28 hours;

[0028] The first cooling rate is 3-6°C / min.

[0029] Optionally, before the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment, the method further comprises:

[0030] purging the adsorbent to be regenerated with nitrogen; and / or

[0031] Before the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment, the method further comprises:

[0032] The adsorbent to be regenerated is washed in an acidic solution.

[0033] The adsorbent regeneration method of an embodiment of the present invention includes: treating the adsorbent to be regenerated at a first temperature in a first atmosphere; treating the adsorbent treated at the first temperature in a second atmosphere; and treating the adsorbent treated at the second temperature in a third atmosphere; the first temperature is 70-180°C, the second temperature is 220-400°C, and the third temperature is 150-200°C; the first atmosphere includes a nitrogen environment or a vacuum environment, the second atmosphere includes a nitrogen environment or a vacuum environment, and the third atmosphere includes an oxidizing atmosphere. The adsorbent regenerated by the above method can adsorb B, P, and metal impurities in trichlorosilane. The regenerated adsorbent has good adsorption effect and can be recycled, reducing costs. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are 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 shall fall within the scope of protection of the present invention.

[0035] The terms "first," "second," and the like in the specification and claims of the present invention are used to distinguish similar objects and are not intended to describe a particular order or precedence. It should be understood that such terms are interchangeable where appropriate, so that embodiments of the present invention can be implemented in sequences other than those described herein. Furthermore, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the connected objects are in an "or" relationship.

[0036] The following is a detailed description of the adsorbent regeneration method provided by the embodiments of the present invention through specific examples.

[0037] The adsorbent regeneration method according to an embodiment of the present invention comprises:

[0038] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment;

[0039] placing the adsorbent treated at the first temperature in a second atmosphere for treatment at a second temperature;

[0040] placing the adsorbent treated at the second temperature at a third temperature and in a third atmosphere for treatment;

[0041] Wherein, the first temperature is 70-180°C, the second temperature is 220-400°C, and the third temperature is 150-200°C;

[0042] The first atmosphere environment includes a nitrogen environment or a vacuum environment, the second atmosphere environment includes a nitrogen environment or a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere; the oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content can be 2-8%, for example, the oxygen content can be 3.6%.

[0043] Organic matter in the adsorbent can be removed through a nitrogen environment or a vacuum environment. By treating it in an oxidizing atmosphere, the residual organic matter and the carbon generated by carbonization can react with oxygen to generate carbon monoxide or carbon dioxide, which is beneficial to the removal of organic matter and carbon.

[0044] In an embodiment of the present invention, before the adsorbent is adsorbed and regenerated, the adsorbent can be prepared by the following preparation method, specifically including:

[0045] Preparation of aqueous phase: In a round-bottom flask, dissolve 5 g of cetyltrimethylammonium bromide (CTAB) in a mixture of distilled water and anhydrous ethanol;

[0046] Preparation of the oil phase: melt an appropriate amount of paraffin wax in a single-necked flask, add 10 mL of tetraethyl orthosilicate (TEOS) at a mass ratio of 10:1, and mix well; the paraffin wax may include at least one of animal wax, vegetable wax, mineral wax, petroleum wax, and synthetic wax;

[0047] The prepared oil phase was quickly poured into the aqueous phase, and then an appropriate amount of 3.2 mL of ammonia water was added. The mixture was stirred mechanically at a high speed of 300-1000 rpm / min for 3 hours, and emulsified at an appropriate temperature for 1-3 hours. Then, the mixture was reacted at a stirring speed of 300-600 rpm / min at 25°C for 3-8 hours. The reaction product was washed with hot water and hot ethanol, and then the washed sample was placed in a 70°C oven and dried for 24 hours to obtain a microcapsule sample coated with paraffin wax.

[0048] The microcapsule sample is immersed in a paraffin-soluble solvent for 48 hours, washed five times, and dried at 70°C for a period of time to obtain an adsorbent. The paraffin-soluble solvent includes at least one of acetone, gasoline, petroleum ether, ethyl ether, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, tetrahydrofuran, xylene, chloroform, carbon tetrachloride, carbon disulfide, and furfural;

[0049] The adsorbent prepared by the above method adsorbs impurities in trichlorosilane. After adsorption, the adsorbent needs to be regenerated because it adsorbs a large amount of impurities. The regeneration method of the adsorbent may include:

[0050] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment;

[0051] placing the adsorbent treated at the first temperature in a second atmosphere for treatment at a second temperature;

[0052] placing the adsorbent treated at the second temperature at a third temperature and in a third atmosphere for treatment;

[0053] Among them, the first temperature is 70-180°C, the second temperature is 220-400°C, and the third temperature is 150-200°C; the first atmosphere environment includes a nitrogen environment or a vacuum environment, the second atmosphere environment includes a nitrogen environment or a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere.

[0054] The regeneration method of the present invention regenerates an adsorbent by placing the adsorbent to be regenerated at a first temperature in a first atmosphere for treatment; placing the adsorbent treated at the first temperature in a second atmosphere for treatment; and placing the adsorbent treated at the second temperature in a third atmosphere for treatment; the first temperature is 70-180°C, the second temperature is 220-400°C, and the third temperature is 150-200°C; the first atmosphere includes a nitrogen environment or a vacuum environment, the second atmosphere includes a nitrogen environment or a vacuum environment, and the third atmosphere includes an oxidizing atmosphere. The adsorbent regenerated by the above method can adsorb B, P, and metal impurities in trichlorosilane. The regenerated adsorbent has good adsorption effect and high adsorption efficiency, can be recycled, and reduces costs.

[0055] In some embodiments, the preparation of the aqueous phase may include:

[0056] FeCl2·4H2O and FeCl3·6H2O are dissolved in a solution of distilled water and anhydrous ethanol. The volume ratio of water to ethanol can be 1:2, the molar ratio of FeCl2·4H2O to FeCl3·6H2O can be 1:(2-3), and the FeCl2·4H2O content can be 0.002 mol. FeCl2·4H2O and FeCl3·6H2O are dissolved in an aqueous solution, and the aqueous solution and oily phase mixture are stirred under alkaline conditions to prepare a microcapsule sample. The paraffin in the microcapsule sample is then removed to obtain an adsorbent. The addition of FeCl2·4H2O and FeCl3·6H2O generates magnetic Fe3O4 particles during the hydrolysis of the silane precursor to form the microcapsule sample. The Fe3O4 particles are evenly dispersed throughout the microcapsule sample, facilitating the adsorption of metallic impurities from trichlorosilane.

[0057] After the adsorbent having Fe3O4 particles is formed, the following steps may be further performed:

[0058] The adsorbent having Fe3O4 particles is washed in an acidic solution.

[0059] During the formation of the microcapsule sample, a small amount of Fe3O4 particles are exposed on the surface of the microcapsule sample. Cleaning with an acidic solution can remove the exposed Fe3O4 particles, preventing the Fe3O4 particles from contaminating trichlorosilane. The acidic solution can include at least one of an aqueous hydrochloric acid solution, an aqueous nitric acid solution, and an aqueous sulfuric acid solution. For example, the acidic solution can include an aqueous hydrochloric acid solution. Since hydrogen chloride is used or generated during the preparation of trichlorosilane and polycrystalline silicon, hydrochloric acid can be used to remove the exposed Fe3O4 particles and prevent the introduction of other impurities.

[0060] After the adsorbent is washed in the acidic solution, the method may further include washing with deionized water and drying after washing.

[0061] The impurities in trichlorosilane are adsorbed by an adsorbent. The adsorbent after adsorption can be regenerated because it adsorbs a large amount of impurities. The regeneration can be performed by the above-mentioned regeneration method of the present invention.

[0062] In some embodiments, when regenerating an adsorbent having Fe3O4 particles, the regeneration process may include:

[0063] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment;

[0064] placing the adsorbent treated at the first temperature in a second atmosphere for treatment at a second temperature;

[0065] placing the adsorbent treated at the second temperature at a third temperature and in a third atmosphere for treatment;

[0066] The adsorbent is then washed in an acidic solution.

[0067] During the adsorption and high-temperature treatment process, Fe₃O₄ particles are exposed on the adsorbent surface. Cleaning with an acidic solution can remove these exposed Fe₃O₄ particles, preventing them from contaminating trichlorosilane. For example, the acidic solution can include aqueous hydrochloric acid. Since hydrogen chloride is used or generated during the trichlorosilane and polysilicon production processes, hydrochloric acid can be used to remove these exposed Fe₃O₄ particles and prevent the introduction of other impurities.

[0068] After washing the adsorbent in an acidic solution, the following steps may also be performed:

[0069] The adsorbent was washed with deionized water and dried.

[0070] In some embodiments of the present invention, the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment may include:

[0071] The adsorbent to be regenerated is placed at a first temperature and in a first atmosphere for treatment for 6-36 hours.

[0072] In some embodiments of the present invention, the step of placing the adsorbent treated at the first temperature in a second atmosphere for treatment may include:

[0073] The adsorbent treated at the first temperature is placed at a second temperature and in a second atmosphere for treatment for 16-48 hours.

[0074] In some embodiments, the second atmosphere is a vacuum environment, and the step of placing the adsorbent treated at the second temperature in a third atmosphere for treatment at a third temperature may include:

[0075] The adsorbent treated at the second temperature is placed at a third temperature and in a third atmosphere for treatment for 6-36 hours.

[0076] In an embodiment of the present invention, after the step of placing the adsorbent treated at the second temperature in a third atmosphere for treatment, the method may further include:

[0077] placing the adsorbent treated at the third temperature at a fourth temperature and in a fourth atmosphere for treatment for 1-2 hours;

[0078] The fourth temperature is 90-130° C., and the fourth atmosphere is an ammonia atmosphere.

[0079] Optionally, the third atmosphere may include ammonia. Organic matter reacts with oxygen to generate some water, which can enter the pores through the ammonia. The ammonia combines with water molecules to form alkaline ammonia water, which increases the alkaline adsorption sites of the adsorbent.

[0080] In some embodiments, the step of subjecting the adsorbent to be regenerated to a first temperature and a first atmosphere for treatment comprises:

[0081] placing the adsorbent to be regenerated in a first atmosphere, heating the temperature from room temperature to a first temperature at a first heating rate, and treating the adsorbent at the first temperature for 2-6 hours;

[0082] The first heating rate is 3-6°C / min;

[0083] Optionally, the step of placing the adsorbent treated at the first temperature in a second atmosphere for treatment includes:

[0084] placing the adsorbent treated at the first temperature in a second atmosphere and heating it from the first temperature to a second temperature at a second heating rate and treating it at the second temperature for 3-8 hours;

[0085] The second heating rate is 4-10°C / min.

[0086] Optionally, the step of placing the adsorbent treated at the second temperature in a third atmosphere for treatment at a third temperature includes:

[0087] placing the adsorbent treated at the second temperature in a third atmosphere and cooling it from the second temperature to a third temperature at a first cooling rate and treating it at the third temperature for 2-5 hours;

[0088] The first cooling rate is 3-6°C / min.

[0089] Optionally, before the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment, the method further comprises:

[0090] The adsorbent to be regenerated is purged with nitrogen. The nitrogen purge can remove organic matter.

[0091] Optionally, before the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment, the method further comprises:

[0092] The adsorbent to be regenerated is washed in an acidic solution. The acidic solution can remove the impurities or metals adsorbed in the adsorbent, making the pores more conducive to the adsorption of impurities.

[0093] In some embodiments, it may also include:

[0094] The adsorbent treated at the third temperature is soaked in an alkaline solution and dried.

[0095] After soaking the adsorbent in an alkaline solution, the adsorbent is given alkaline sites, which can increase the adsorption efficiency. The alkaline solution can include but is not limited to NaOH, KOH, Ba(OH)2, etc.

[0096] The present invention will be further described below through some specific examples.

[0097] Preparation process of adsorbent to be regenerated:

[0098] Preparation of aqueous phase: In a round-bottom flask, dissolve 5 g of cetyltrimethylammonium bromide (CTAB) in a mixture of distilled water and anhydrous ethanol;

[0099] Preparation of oil phase: melt an appropriate amount of paraffin wax in a single-necked flask, add 10 mL of tetraethyl orthosilicate (TEOS) at a mass ratio of 10:1, and mix well.

[0100] The prepared oil phase was quickly poured into the water phase, and then an appropriate amount of 3.2 mL of ammonia water was added. The mixture was stirred mechanically at high speed for 3 h at a stirring speed of 300-1000 rpm / min, and emulsified at an appropriate temperature for 1-3 h.

[0101] Then, the mixture was placed at 25°C and stirred at a speed of 300-600 rpm / min for 3-8 hours, the reaction product was washed with hot water and hot ethanol, and the washed sample was placed in an oven at 70°C and dried for 24 hours to obtain a microcapsule sample coated with paraffin wax;

[0102] The microcapsule sample is immersed in a solvent that can dissolve paraffin for 48 hours, washed 5 times, and dried at 70°C for a period of time to obtain an adsorbent; the solvent that can dissolve paraffin can include ether and xylene;

[0103] The adsorbent prepared by the above method is used to adsorb impurities in trichlorosilane. After adsorption, the adsorption effect of the adsorbent becomes poor and needs to be regenerated. Therefore, the adsorbent prepared by the above method can be used as the adsorbent to be regenerated after adsorbing impurities in trichlorosilane.

[0104] Example 1

[0105] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment for 6 hours;

[0106] placing the adsorbent treated at the first temperature in a second atmosphere at a second temperature for 48 hours;

[0107] placing the adsorbent treated at the second temperature in a third atmosphere for treatment for 6 hours;

[0108] The first temperature is 70°C, the second temperature is 400°C, and the third temperature is 200°C.

[0109] The first atmosphere environment includes a vacuum environment, the second atmosphere environment includes a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere, the oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content is 3.6%;

[0110] Example 2

[0111] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment for 36 hours;

[0112] placing the adsorbent treated at the first temperature in a second atmosphere for treatment for 16 hours;

[0113] placing the adsorbent treated at the second temperature in a third atmosphere for treatment for 36 hours;

[0114] Among them, the first temperature is 180°C, the second temperature is 220°C, and the third temperature is 150°C;

[0115] The first atmosphere environment includes a vacuum environment, the second atmosphere environment includes a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere, the oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content is 3.6%;

[0116] Example 3

[0117] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment for 24 hours;

[0118] placing the adsorbent treated at the first temperature in a second atmosphere for treatment for 32 hours;

[0119] placing the adsorbent treated at the second temperature in a third atmosphere for treatment for 16 hours;

[0120] The first temperature is 180°C, the second temperature is 300°C, and the third temperature is 180°C.

[0121] The first atmosphere environment includes a vacuum environment, the second atmosphere environment includes a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere, the oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content is 3.6%;

[0122] Example 4

[0123] placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment for 6 hours;

[0124] placing the adsorbent treated at the first temperature in a second atmosphere at a second temperature for 48 hours;

[0125] placing the adsorbent treated at the second temperature in a third atmosphere for treatment for 6 hours;

[0126] The first temperature is 70°C, the second temperature is 400°C, and the third temperature is 200°C.

[0127] The first atmosphere environment includes a vacuum environment, the second atmosphere environment includes a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere, the oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content is 3.6%;

[0128] placing the adsorbent treated at the third temperature at a fourth temperature and in a fourth atmosphere for treatment for 1-2 hours;

[0129] The fourth temperature is 90° C., and the fourth atmosphere is an ammonia atmosphere.

[0130] Example 5

[0131] The difference between Example 5 and Example 4 is that the fourth temperature is 130°C.

[0132] Example 6

[0133] The difference between Example 6 and Example 1 is that the third atmosphere environment includes nitrogen, oxygen and ammonia, with the oxygen content being 3.6% and the ammonia content being 6.5%.

[0134] Example 7

[0135] placing the adsorbent to be regenerated in a first atmosphere and heating it from room temperature to a first temperature at a first heating rate and treating it at the first temperature for 6 hours, wherein the first heating rate is 3°C / min;

[0136] The adsorbent treated at the first temperature is placed in a second atmosphere and heated from the first temperature to a second temperature at a second heating rate and treated at the second temperature for 36 hours, wherein the second heating rate is 10° C. / min.

[0137] The adsorbent treated at the second temperature is placed in a third atmosphere and cooled from the second temperature to a third temperature at a first cooling rate and treated at the third temperature for 6 hours, wherein the first cooling rate is 3° C. / min.

[0138] The first temperature is 70°C, the second temperature is 400°C, and the third temperature is 200°C;

[0139] The first atmosphere is a vacuum environment, the second atmosphere is a vacuum environment, and the third atmosphere is an oxidizing atmosphere. The oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content is 3.6%.

[0140] Example 8

[0141] placing the adsorbent to be regenerated in a first atmosphere and heating it from room temperature to a first temperature at a first heating rate and treating it at the first temperature for 28 hours, wherein the first heating rate is 6°C / min;

[0142] The adsorbent treated at the first temperature is placed in a second atmosphere and heated from the first temperature to a second temperature at a second heating rate and treated at the second temperature for 8 hours, wherein the second heating rate is 4° C. / min.

[0143] The adsorbent treated at the second temperature is placed in a third atmosphere and cooled from the second temperature to a third temperature at a first cooling rate and treated at the third temperature for 28 hours, wherein the first cooling rate is 6° C. / min.

[0144] The first temperature is 180°C, the second temperature is 220°C, and the third temperature is 150°C;

[0145] The first atmosphere is a vacuum environment, the second atmosphere is a vacuum environment, and the third atmosphere is an oxidizing atmosphere. The oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content is 3.6%.

[0146] Example 9

[0147] placing the adsorbent to be regenerated in a first atmosphere and heating it from room temperature to a first temperature at a first heating rate and treating it at the first temperature for 16 hours, wherein the first heating rate is 4°C / min;

[0148] The adsorbent treated at the first temperature is placed in a second atmosphere and heated from the first temperature to a second temperature at a second heating rate and treated at the second temperature for 24 hours, wherein the second heating rate is 6° C. / min.

[0149] The adsorbent treated at the second temperature is placed in a third atmosphere and cooled from the second temperature to a third temperature at a first cooling rate and treated at the third temperature for 12 hours, wherein the first cooling rate is 3° C. / min.

[0150] The first temperature is 180°C, the second temperature is 220°C, and the third temperature is 150°C;

[0151] The first atmosphere is a vacuum environment, the second atmosphere is a vacuum environment, and the third atmosphere is an oxidizing atmosphere. The oxidizing atmosphere includes nitrogen and oxygen, and the oxygen content is 3.6%.

[0152] Comparative Example 1

[0153] Unregenerated adsorbent.

[0154] Comparative Example 2

[0155] The difference between Comparative Example 2 and Example 1 is that the third atmosphere environment is a vacuum environment.

[0156] Adsorption was performed using the adsorbents in Examples 1-9 and the comparative example. Before adsorption, the impurity contents in trichlorosilane were: B was 227.6 ppb, P was 281.7 ppb, and metal impurities were 153.4 ppb.

[0157] The regenerated adsorbent was placed in trichlorosilane at a temperature of 20° C. for 6 hours. The mass of the adsorbent was 10% of the mass of the trichlorosilane. The adsorbent was then removed and the content of impurities in the trichlorosilane was detected. The specific detection results are shown in Table 1.

[0158] Table 1 Test results

[0159] name B / ppb P / ppb Metal impurities / ppb Example 1 50.7 67.5 46.4 Example 2 46.8 63.4 47.8 Example 3 47.5 61.1 46.1 Example 4 38.4 52.8 41.7 Example 5 40.8 53.1 43.5 Example 6 37.2 43.5 36.7 Example 7 18.6 25.4 20.1 Example 8 10.4 26.1 16.5 Example 9 15.8 24.7 18.4 Comparative Example 1 137.9 158.7 105.6 Comparative Example 2 76.3 83.5 59.3

[0160] As can be seen from Table 1, the regenerated adsorbent can adsorb B, P, and metal impurities in trichlorosilane. The regenerated adsorbent has a good adsorption effect. The adsorption effects in Examples 7 to 9 are good and can be recycled to reduce costs.

[0161] The above describes the embodiments of the present invention, but the present invention is not limited to the above specific implementation methods. The above specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A regeneration method for trichlorosilane impurity removal adsorbent, characterized in that: include: The adsorbent of the magnetic Fe3O4 particles to be regenerated is placed in a first atmosphere at a first temperature for treatment; placing the adsorbent treated at the first temperature in a second atmosphere for treatment at a second temperature; placing the adsorbent treated at the second temperature at a third temperature and in a third atmosphere for treatment; The adsorbent is washed in an acidic solution, washed with deionized water and dried; Wherein, the first temperature is 70-180°C, the second temperature is 220-400°C, and the third temperature is 150-200°C; The first atmosphere environment includes a nitrogen environment or a vacuum environment, the second atmosphere environment includes a nitrogen environment or a vacuum environment, and the third atmosphere environment includes an oxidizing atmosphere; The step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment comprises: placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment for 6-36 hours; The step of placing the adsorbent treated at the first temperature in a second atmosphere for treatment comprises: placing the adsorbent treated at the first temperature in a second atmosphere at a second temperature for treatment for 16-48 hours; The second atmosphere is a vacuum environment, and the step of placing the adsorbent treated at the second temperature in a third atmosphere for treatment at a third temperature comprises: The adsorbent treated at the second temperature is placed at a third temperature and in a third atmosphere for treatment for 6-36 hours.

2. The method according to claim 1, characterized in that After the step of placing the adsorbent treated at the second temperature in a third atmosphere for treatment, the method further comprises: placing the adsorbent treated at the third temperature at a fourth temperature and in a fourth atmosphere for treatment for 1-2 hours; The fourth temperature is 90-130° C., and the fourth atmosphere is an ammonia atmosphere.

3. The method according to claim 1, characterized in that The third atmosphere includes ammonia.

4. The method according to claim 1, wherein The step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment comprises: placing the adsorbent to be regenerated in a first atmosphere, heating the temperature from room temperature to a first temperature at a first heating rate, and treating the adsorbent at the first temperature for 6-28 hours; The first heating rate is 3-6°C / min.

5. The method according to claim 1 or 4, characterized in that The step of placing the adsorbent treated at the first temperature in a second atmosphere for treatment comprises: placing the adsorbent treated at the first temperature in a second atmosphere and heating it from the first temperature to a second temperature at a second heating rate and treating it at the second temperature for 16-36 hours; The second heating rate is 4-10°C / min.

6. The method according to claim 5, characterized in that The step of placing the adsorbent treated at the second temperature at a third temperature and in a third atmosphere for treatment comprises: placing the adsorbent treated at the second temperature in a third atmosphere, cooling the adsorbent from the second temperature to a third temperature at a first cooling rate, and treating the adsorbent at the third temperature for 6-28 hours; The first cooling rate is 3-6°C / min.

7. The method according to claim 1, wherein Before the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment, the method further comprises: purging the adsorbent to be regenerated with nitrogen; and / or Before the step of placing the adsorbent to be regenerated at a first temperature and in a first atmosphere for treatment, the method further comprises: The adsorbent to be regenerated is washed in an acidic solution.