Adsorbent for crude sulfur refining and preparation method thereof

Abstract

The present invention discloses an adsorbent for refining crude sulfur. The preparation method comprises the following steps: S1: mixing an alkaline reagent and sodium metaaluminate, adding an appropriate amount of water, and thoroughly stirring and dissolving the mixture to prepare solution I; S2: adding water to sodium silicate and stirring until completely dissolved to obtain a sodium silicate solution, which is then poured into solution I and vigorously stirred to obtain a milky white gel; S3: placing the gel, urea, and polyacrylamide in a hydrothermal reactor for crystallization, filtering, washing, and drying the mixture to obtain a solid II; S4: placing the solid II in a mixed solution containing calcium, iron, and cobalt, adding a glutaraldehyde solution while stirring, and adjusting the pH simultaneously. After water bath treatment for a period of time, the mixture is filtered, washed, and dried in an oven. After complete drying, the sample is placed in a muffle furnace for calcining, extrusion molding, drying, and calcining to prepare a spherical adsorbent. The adsorbent obtained by this preparation method has good adsorption effect on naphthalene and phenol, and has high adsorbent strength, making it suitable for promotion and application.

Description

Technical Field

[0001] The present invention relates to the technical field of crude sulfur purification, and in particular to an adsorbent for crude sulfur refining and a preparation method thereof. Background Art

[0002] Coke oven gas from a coking plant undergoes wet desulfurization to produce crude sulfur as a byproduct. However, because the gas contains large amounts of coal tar and ash, these substances enter the crude sulfur, resulting in a low sulfur content and a black color. This makes the crude sulfur unsuitable for direct industrial use and its value is low. Therefore, the recovered crude sulfur needs to be further purified to meet industrial production needs.

[0003] The most abundant impurities in coal tar are naphthalene and phenol. Numerous methods exist for their removal. Currently, many coking plants use adsorption to remove impurities from coal gas or crude sulfur after desulfurization. Adsorption involves the use of solid adsorbents to absorb and treat harmful substances. The choice of adsorbent determines the effectiveness of the adsorption process. Adsorbents offer advantages such as large surface area, ease of adsorption and desorption, easy availability, and low cost. Commonly used adsorbents include crushed corn cobs, sawdust, rice husks, ceramic, and metal filters. However, practice has shown that these commonly used adsorbents have low tar removal efficiency, far from meeting requirements. Furthermore, operating costs are high, and the equipment required is typically bulky and requires significant floor space.

[0004] Patent CN201410109860.9 discloses a method for purifying crude sulfur, which comprises mixing crude sulfur and an extractant in a sulfur dissolving kettle at a weight ratio of 1:1-1:10, and adding an adsorbent in a mass ratio of 1:2-1:12 to the crude sulfur; heating to 60-80°C, and then slowly raising the temperature to 115-150°C; after maintaining the temperature for 10-30 minutes, the material enters a heating overflow at 80-110°C, and when the temperature reaches 80-110°C, the adsorbent or residue is removed, and the overflow enters a storage tank with stirring, and after cooling to 65-75°C, it is filtered to obtain the first crystallized sulfur. In this patent, impurities in crude sulfur are initially removed using an adsorbent, wherein the adsorbent is activated carbon, diatomaceous earth or activated alumina. Although the cost of the above-mentioned activated carbon, diatomaceous earth or activated alumina is relatively low and can reduce the cost of purifying crude sulfur, it is found that the use of the above-mentioned adsorbents still results in residual impurities such as phenol and naphthalene in the final refined sulfur, and the impurities in the crude sulfur cannot be completely removed, affecting the quality of the final product.

[0005] Therefore, it is particularly important for coking plants to develop an adsorbent that can be applied to the purification process of crude sulfur and has good impurity removal effect. Summary of the Invention

[0006] In order to solve the problems existing in the above-mentioned prior art, such as the poor effect of adsorbents in removing phenol and naphthalene from crude sulfur, and the need for special filters when removing crude sulfur impurities, which increases the cost investment of coking plants, the present invention provides an adsorbent for crude sulfur refining and a preparation method thereof.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing an adsorbent for crude sulfur refining comprises the following steps: S1: mixing an alkaline reagent and sodium metaaluminate, adding an appropriate amount of water, stirring and dissolving the mixture to prepare a solution I;

[0009] S2: Sodium silicate was added to water and stirred until completely dissolved to obtain a sodium silicate solution, which was then poured into solution I and stirred vigorously to obtain a milky white gel;

[0010] S3: placing the gel, urea, and polyacrylamide in a hydrothermal reactor for crystallization, and filtering, washing, and drying the resulting solid to obtain solid II;

[0011] S4: Place solid II in a mixed solution containing calcium, iron, and cobalt, add glutaraldehyde solution while stirring, and adjust the pH at the same time. After treating in a water bath for a period of time, filter and wash it and place it in an oven to dry. After it is completely dried, place it in a muffle furnace to calcine the sample. After mixing the calcined sample, binder and water, extrude it, dry it and calcine it to prepare a spherical adsorbent.

[0012] Furthermore, in step S1, the alkaline reagent is sodium hydroxide, and the molar ratio of sodium hydroxide to sodium aluminate is 1:6.

[0013] Furthermore, the concentration of the sodium silicate solution in step S2 is 0.1-1 mol / L.

[0014] Furthermore, the mass ratio of gel, urea and polyacrylamide in step S3 is 50:1-5:0.5-3, the temperature during the crystallization process is 80-95° C. for 4-6 hours, and after crystallization, the product is filtered and washed until the pH of the filtrate is less than 9.

[0015] Furthermore, in step S4, the mixed solution containing calcium, iron and cobalt is prepared by weighing calcium, cobalt and iron according to a molar ratio of 1:0.1-0.5:5-20 and dissolving the corresponding chlorides in deionized water to prepare a mixed solution.

[0016] Furthermore, the volume ratio of the glutaraldehyde solution to the mixed solution is 10:1.

[0017] Furthermore, after adding the glutaraldehyde solution, the pH of the solution system was adjusted to 9-10 with 1 mol / L sodium hydroxide, and the temperature was 80°C.

[0018] Furthermore, the binder in step S4 is kaolin.

[0019] Furthermore, based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of water added is 30%; the extrusion molding is carried out in a vacuum extrusion molding machine, the temperature is controlled at 35°C, the extrusion pressure is about 18MPa, and the vacuum degree is 8Kpa.

[0020] An adsorbent obtained according to any one of the above preparation methods.

[0021] The present invention has the following beneficial effects:

[0022] 1. The present invention provides an adsorbent for crude sulfur refining. The adsorbent is prepared by adding metal chlorides containing calcium, cobalt, and iron, thereby improving the removal of naphthalene and phenol from the crude sulfur. Simultaneously, by controlling the amount of glutaraldehyde added, as well as the pH and temperature of the system during the preparation process, an adsorbent with optimal impurity removal is obtained, providing a basis for obtaining sulfur of higher purity.

[0023] 2. The present invention provides an adsorbent for crude sulfur refining. By controlling the silicon-aluminum ratio during the preparation process, optimizing the crystallization conditions, and adding an appropriate amount of binder during the molding process, a high-strength adsorbent is obtained. The adsorbent can better adapt to different crude sulfur purification conditions, thereby extending the service life of the adsorbent.

[0024] 3. The present invention provides an adsorbent for crude sulfur refining. The preparation process of the adsorbent is simple, the operation process is convenient, and it is suitable for promotion and application. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments.

[0026] Example 1

[0027] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0028] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0029] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0030] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0031] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0032] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0033] Example 2

[0034] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0035] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0036] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:1:3 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0037] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0038] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0039] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0040] Example 3

[0041] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0042] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0043] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:5:0.5 in a hydrothermal reactor for crystallization. The crystallization temperature is controlled at 90°C for 4 hours. After crystallization, the mixture is filtered and washed until the pH of the washing liquid is less than 9. The filter cake is dried in an oven at 60°C to obtain solid II.

[0044] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0045] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0046] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0047] Example 4

[0048] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0049] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0050] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0051] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.1:20, and dissolve them in deionized water to prepare a mixed solution for later use.

[0052] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0053] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0054] Example 5

[0055] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0056] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0057] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0058] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:5, and dissolve them in deionized water to prepare a mixed solution for later use.

[0059] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0060] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0061] Example 6

[0062] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0063] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 1 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0064] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0065] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0066] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0067] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0068] Comparative Example 1

[0069] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:3, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0070] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0071] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0072] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0073] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0074] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0075] Comparative Example 2

[0076] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0077] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0078] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0079] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0080] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0081] Based on the mass of the calcined sample, the amount of kaolin added is 4%, and the amount of deionized water added is 40%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0082] Comparative Example 3

[0083] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0084] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0085] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0086] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0087] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0088] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0089] Comparative Example 4

[0090] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0091] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0092] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:0.1:10 in a hydrothermal reactor for crystallization. The crystallization temperature is controlled at 90°C for 6 hours. After crystallization, the mixture is filtered and washed until the pH of the washing liquid is less than 9. The filter cake is dried in an oven at 60°C to obtain solid II.

[0093] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0094] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0095] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0096] Comparative Example 5

[0097] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0098] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0099] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 70°C for 2 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0100] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0101] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0102] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0103] Comparative Example 6

[0104] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0105] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0106] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0107] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:5:30, and dissolve them in deionized water to prepare a mixed solution for later use.

[0108] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0109] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0110] Comparative Example 7

[0111] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0112] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0113] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0114] S4: Weigh a certain amount of calcium chloride and ferric chloride according to the corresponding metal molar ratio of 5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0115] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0116] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0117] Comparative Example 8

[0118] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0119] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0120] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0121] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0122] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 11. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0123] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a honeycomb adsorbent.

[0124] Comparative Example 9

[0125] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0126] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0127] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0128] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0129] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:10, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C during the entire process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0130] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0131] Comparative Example 10

[0132] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0133] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0134] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0135] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0136] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:4. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 80°C throughout the process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0137] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0138] Comparative Example 11

[0139] S1: Weigh a certain amount of sodium hydroxide and sodium metaaluminate in a molar ratio of sodium hydroxide to sodium metaaluminate of 1:6, mix the sodium hydroxide and sodium metaaluminate, add an appropriate amount of deionized water (the mass of the deionized water being 10 times the total mass of the sodium hydroxide and sodium metaaluminate), stir and dissolve thoroughly to prepare Solution I;

[0140] S2: Weigh a certain amount of sodium silicate and add deionized water. Stir until completely dissolved to obtain a 0.5 mol / L sodium silicate solution. Pour the sodium silicate solution into solution I and stir rapidly to obtain a milky white gel.

[0141] S3: placing gel, urea, and polyacrylamide in a mass ratio of 50:2:2 in a hydrothermal reactor for crystallization at a controlled temperature of 90°C for 6 hours. After crystallization, the mixture was filtered and washed until the pH of the washing solution was less than 9. The filter cake was dried in an oven at 60°C to obtain solid II.

[0142] S4: Weigh a certain amount of corresponding reagents, including calcium chloride, cobalt chloride and ferric chloride, according to a corresponding metal molar ratio of 1:0.5:15, and dissolve them in deionized water to prepare a mixed solution for later use.

[0143] Solid II was placed in a mixed solution at a solid-liquid volume ratio of 1:20, and glutaraldehyde was added while stirring. The volume ratio of glutaraldehyde to the mixed solution was 10:1. At the same time, 1 mol / L sodium hydroxide was added to adjust the pH of the system to 9-10. The temperature was controlled at 50°C during the entire process. After stirring for 2 hours, it was filtered and washed and then placed in an oven to dry. After complete drying, the sample was placed in a muffle furnace and calcined at 400°C for 5 hours.

[0144] Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of deionized water added is 30%. The calcined sample, kaolin and water are mixed and stirred evenly, and then extruded in a vacuum extruder. The extrusion process temperature is controlled at 35°C, the extrusion pressure is 18MPa, and the vacuum degree is 8Kpa. After extrusion molding, the wet strip adsorbent is dried in a drying oven and then placed in a muffle furnace for calcination at a heating rate of 10°C-15°C / h, heated to 500°C, and calcined for 4h to prepare a spherical adsorbent.

[0145] Evaluation method of adsorption effect of adsorbent in crude sulfur purification process:

[0146] 20 kg of crude sulfur was added to a sulfur melting apparatus, and 5 kg of deionized water and 1 kg of the adsorbent prepared in Examples 1-5 and Comparative Examples 1-11 were added at room temperature. The sulfur melting apparatus was heated to 120°C and stirred for 2 hours, followed by separation of the middle liquid sulfur layer. The separated liquid sulfur layer was then hot-filtered at 130°C to separate the adsorbent after adsorption, thereby obtaining liquid sulfur. The liquid sulfur was cooled to room temperature to obtain the final sulfur product. The crude sulfur and the final sulfur product were then tested for phenol and naphthalene content, thereby verifying the adsorption performance of the adsorbent.

[0147] The adsorbents prepared in Examples 1-6 and Comparative Examples 6-11 were used to test the adsorption efficiency of phenol and naphthalene. The specific test results are shown in Table 1 below.

[0148] Table 1

[0149]

[0150] According to the comparison of the test results in Table 1 above, it can be seen from the results of Comparative Examples 6 and 7 that changing the molar ratio of calcium, cobalt and iron, or removing one metal, the adsorption effect of the final adsorbent will be significantly reduced.

[0151] According to the test results shown in Comparative Examples 8 and 9, changing the system pH adjusted with sodium hydroxide in the adsorbent preparation step S4 will affect the adsorption effect of phenol, while changing the solid-liquid volume ratio of solid II and the mixed solution will affect the adsorption effect of naphthalene.

[0152] According to the test results of Comparative Examples 10 and 11, changing the volume ratio of glutaraldehyde to the mixed solution or changing the temperature of the entire operation process of the solid II and the mixed solution in step S4 will also affect the final adsorption effect.

[0153] At the same time, in order to compare the effects of the adsorbent prepared in Example 1 with the adsorbent used in the existing crude sulfur purification process, the activated carbon adsorbent used in the prior art was compared. It was found that when activated carbon or activated alumina was used, the adsorption rate of phenol exhibited by the activated carbon was 90%, and the adsorption rate of naphthalene was 93%; the adsorption rate of phenol exhibited by the activated alumina was 92%, and the adsorption rate of naphthalene was 89%. Compared with the adsorption effect of Example 1 in Table 1 above, the adsorption effect of Example 1 is relatively better.

[0154] The strip catalysts prepared in Example 1 and Comparative Examples 1-5 were placed in an intelligent particle strength testing machine, and the samples were gradually stressed until they broke; this step was repeated 15 times until the test was completed. The test results are summarized in Table 2 below.

[0155] Table 2

[0156]

[0157] Combined with the adsorbent strength tested in Table 2 above, changing factors such as the crystallization conditions, the concentration of sodium silicate, and the mass ratio of gel, urea, and polyacrylamide during the adsorbent preparation process will affect the adsorbent strength to a certain extent. Therefore, the catalyst prepared in Example 1 can withstand higher mechanical strength, adapt to more stringent adsorption conditions, and have a longer service life.

Claims

1. A method for preparing an adsorbent for crude sulfur refining, characterized in that: The following steps are involved: S1: Mix the alkaline reagent and sodium metaaluminate, add an appropriate amount of water, stir thoroughly, and dissolve to prepare solution I; S2: Sodium silicate is added to water and stirred until completely dissolved to obtain a sodium silicate solution. The sodium silicate solution is poured into solution I and stirred vigorously to obtain a milky white gel; S3: placing the gel, urea and polyacrylamide in a hydrothermal reactor for crystallization, filtering, washing and drying the crystallized solid to obtain solid II; S4: placing solid II in a mixed solution containing calcium, iron, and cobalt, adding glutaraldehyde solution while stirring, and adjusting the pH at the same time. After treating in a water bath for a period of time, filtering, washing, and drying in an oven, the sample is calcined in a muffle furnace after complete drying. The calcined sample, binder, and water are mixed, extruded, dried, and calcined to prepare a spherical adsorbent; In step S1, the alkaline reagent is sodium hydroxide, and the molar ratio of sodium hydroxide to sodium aluminate is 1:6; The concentration of the sodium silicate solution in step S2 is 0.1-1 mol / L; The mass ratio of gel, urea and polyacrylamide in step S3 is 50:1-5:0.5-3, the temperature during the crystallization process is 80-95° C., the crystallization is performed for 4-6 hours, and after the crystallization, the solution is filtered and washed until the pH of the filtrate is less than 9; Preparation of a mixed solution containing calcium, iron, and cobalt in step S4: weighing calcium, cobalt, and iron in a molar ratio of 1:0.1-0.5:5-20 and dissolving the corresponding chlorides in deionized water to prepare a mixed solution; The volume ratio of the glutaraldehyde solution to the mixed solution is 10:1; after adding the glutaraldehyde solution, the pH of the solution system is adjusted to 9-10 with 1 mol / L sodium hydroxide, and the temperature is controlled at 80° C. throughout the process.

2. The method for preparing an adsorbent according to claim 1, wherein: The binder in step S4 is kaolin.

3. The method for preparing an adsorbent according to claim 2, wherein: Based on the mass of the calcined sample, the amount of kaolin added is 8%, and the amount of water added is 30%; The extrusion molding is carried out in a vacuum extrusion molding machine, with the temperature controlled at 35° C., the extrusion pressure at 18 MPa, and the vacuum degree at 8 KPa.

4. An adsorbent obtained by the preparation method of the adsorbent according to any one of claims 1 to 3.

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