Activated carbon drop ball forming slurry, activated carbon and preparation method of activated carbon drop ball forming slurry

Abstract

The invention relates to the technical field of drop ball forming, in particular to activated carbon drop ball forming slurry, activated carbon and a preparation method of the activated carbon drop ball forming slurry. 0.1 to 50 weight percent of activated carbon powder; 0.01 to 10 weight percent of alginate; the pH value of the slurry is 8-14. The pH value of the slurry is adjusted by adding alkali, so that drippers are not blocked and dripped balls are continuously carried out when activated carbon particles are prepared through dripped ball forming, the dripped ball particles are smoothly formed in the preparation process, the drippers are not easily blocked, and the method can effectively improve and enhance the integrity of the particles and restrain the blocking problem in the dripped ball process.

Description

Technical Field

[0001] The present invention relates to the technical field of dropping ball forming, and specifically relates to a slurry for activated carbon dropping ball forming, activated carbon, and a preparation method thereof. Background Art

[0002] Activated carbon catalysts and adsorbents are important consumables in chemical engineering and industrial catalysis, and are widely used in high-purity gases, liquids, and the petrochemical industry. Activated carbon is suitable for use as a catalyst and adsorbent because it has a relatively developed pore structure and rich surface functional group modifications microscopically. For example, activated carbon adsorbents used in the field of tail gas treatment can be used as organic synthesis catalysts after loading precious metals, etc., and their uses are very extensive. Moreover, due to the wide source, low price, and low specific gravity of activated carbon, it is a preferred option for the selection of various common catalyst and adsorbent carriers.

[0003] The use of activated carbon requires a certain morphology, including spherical morphology, strip morphology, honeycomb morphology, etc. In some fixed beds of catalytic and adsorption devices, in order to avoid uneven density during the loading of activated carbon-based materials, the size of activated carbon needs to be highly regular. At this time, the dropping ball method can achieve the formation of small balls with highly uniform size and ideal roundness.

[0004] The dropping ball method is a common technique for catalyst / adsorbent forming. The alumina industry often uses oil ammonia columns and hot oil columns for forming, and a large amount of information has been disclosed for such techniques. For example, CN115920977A and CN115739198A use alumina sol and ammonia-containing oil phase to form alumina small balls. However, this method requires the precursor to react with alkaline substances such as ammonia and is not suitable for the ball forming of inert activated carbon. For activated carbon, it is difficult to form balls using oil ammonia columns and hot oil columns. Another example is that CN115608405A mixes an alumina precursor and an MFI structure molecular sieve, makes an acidic sol, and then performs oil ammonia column dropping balls. Although this method can make the inert MFI molecular sieve form balls, this method results in more alumina mixed in the obtained small balls, reducing the purity of the MFI molecular sieve small balls. It is not feasible to obtain high-purity activated carbon small balls using this method. Summary of the Invention

[0005] The object of the present invention is to overcome the problems that the existing activated carbon has uneven particle size and is difficult to be evenly dispersed in the solution, resulting in blockage of the dropper during the dropping ball process and inability to continuously drop balls, thereby increasing the difficulty and cost of industrial production. A slurry for forming activated carbon dropping balls, activated carbon and its preparation method are provided. By adjusting the pH of the slurry, the dropper is not blocked and the dropping balls can be continuously carried out during the preparation of activated carbon particles by dropping balls, while maintaining good catalytic performance. Compared with the technical routes such as rolling balls, the activated carbon small balls obtained by this method have extremely high particle size uniformity, and smaller particles with a size of 1-2 mm can be prepared. Compared with the technical route method based on the dropping ball method, the dropper is not easily blocked during the preparation of small balls. Therefore, compared with other preparation methods, this method has low cost, simple operation and simple equipment, and is an excellent method for preparing activated carbon particles.

[0006] The inventors of the present invention disclosed in CN116020334A that the use of alginate and inorganic precursors mixed dropping balls can effectively expand the applicability of dropping ball forming. However, when used for dropping balls of activated carbon, if alginate and activated carbon are directly mixed and stirred into a slurry and dropped into the reaction solution to form dropping balls, and then the activated carbon particles are prepared by drying and calcination, due to the characteristics of uneven particle size of the activated carbon itself and difficulty in being evenly dispersed in the solution, the dropper is blocked during the dropping ball process and continuous dropping balls cannot be carried out, thereby increasing the difficulty and cost of industrial production. Therefore, it is crucial to solve the problem of blockage of the dropper by the slurry during the preparation of particulate matter.

[0007] To achieve the above object, in the first aspect of the present invention, a slurry for forming activated carbon dropping balls is provided. Based on the total weight of the slurry, the slurry includes:

[0008] Solvent 50-99.5 wt%;

[0009] Activated carbon powder 0.1-50 wt%;

[0010] Alginate 0.01-10 wt%;

[0011] The pH value of the slurry is 8-14.

[0012] In the second aspect of the present invention, a preparation method of the slurry of the present invention is provided. The preparation method of the slurry includes:

[0013] (1) After mixing the activated carbon with the solvent, add alginate;

[0014] (2) Add alkali to adjust the pH.

[0015] In the third aspect of the present invention, a preparation method of activated carbon particles is provided. The method includes:

[0016] (I) Drop the slurry of the present invention into the forming aid with a dropper, and form solidified particles by dropping and forming spheres; the forming aid is selected from a solution containing polyvalent metal cations, and the concentration of metal cations is not less than 0.01 wt%.

[0017] (II) Separate, dry and calcine the solidified particles to obtain activated carbon particles.

[0018] The fourth aspect of the present invention provides activated carbon particles prepared by the preparation method of the activated carbon particles of the present invention.

[0019] Through the above technical solution, by adding an alkali to adjust the pH of the slurry, it is possible to prevent the dropper from being blocked and the continuous dropping and forming of spheres during the preparation of activated carbon particles by dropping and forming spheres, ensuring the smooth forming of the dropping and forming particles during the preparation process and not easily blocking the dropper. This method can effectively improve and enhance the integrity of the particles and inhibit the blocking problem during the dropping and forming process.

[0020] As a catalyst and adsorbent, activated carbon is an important consumable in chemical engineering and industrial catalysis, and is widely used in high-purity gases, liquids, and the petrochemical industry. The preparation method of the activated carbon particles of the present invention has the advantages of high product uniformity, easy availability of equipment, simple operation steps, etc., and is easy to realize industrial scale-up production, providing more activated carbon particle products for the chemical industry. Detailed Embodiments

[0021] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values and individual point values of each range, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0022] The first aspect of the present invention provides a slurry for forming activated carbon by dropping and forming spheres. Based on the total weight of the slurry, the slurry includes:

[0023] Solvent 50 - 99.5 wt%;

[0024] Activated carbon powder 0.1 - 50 wt%;

[0025] Alginate 0.01 - 10 wt%;

[0026] The pH value of the slurry is 8 - 14. By adjusting the pH of the slurry, it is possible to prevent the dropper from being blocked and the continuous dropping and forming of spheres during the preparation of activated carbon particles by dropping and forming spheres, while maintaining good catalytic performance itself.

[0027] In the present invention, the slurry contains an alkali. The present invention does not have a special limitation on the alkali content in the slurry, and the alkali content only needs to make the pH of the slurry 8 - 14.

[0028] According to a preferred embodiment of the present invention, the pH of the slurry is 8 - 12.

[0029] According to a preferred embodiment of the present invention, in the slurry, the content of activated carbon powder is 5 - 25 wt%.

[0030] According to a preferred embodiment of the present invention, in the slurry, the content of alginate is 0.05 - 3 wt%.

[0031] In the present invention, there is no particular limitation on the type of the base. According to a preferred embodiment of the present invention, the base is selected from soluble hydroxides, soluble carbonates, soluble bicarbonates, NH 3 , NH 3 ·H 2 O, and one or more of C1 - C6 organic amines.

[0032] According to a preferred embodiment of the present invention, the base is selected from NH 3 , NH 3 ·H 2 O, ammonium carbonate, ammonium bicarbonate, and one or more of C1 - C6 organic amines; more preferably NH 3 ·H 2 O.

[0033] In the present invention, the optional range of C1 - C6 organic amines is relatively wide. For illustrative purposes only, but not limiting the scope of the present invention thereby. According to a preferred embodiment of the present invention, the C1 - C6 organic amines are selected from one or more of methylamine, monoethylamine, diethylamine, ethylenediamine, propylamine, triethylamine, propylenediamine, butanediamine, and hexanediamine.

[0034] In the present invention, there is no particular limitation on the source of the activated carbon powder. According to a preferred embodiment of the present invention, the activated carbon includes any activated carbon that can be uniformly dispersed, such as activated carbon powder prepared from wood activated carbon, fruit shell (fruit pit) activated carbon, coal - based activated carbon, petroleum - based activated carbon, recycled carbon, agricultural and sideline products, etc.

[0035] In the present invention, the optional range of the sieving mesh number of the activated carbon powder is relatively wide. For illustrative purposes only, but not limiting the scope of the present invention thereby. According to a preferred embodiment of the present invention, the sieving mesh number of the activated carbon powder is not less than 80 mesh, preferably not less than 200 mesh.

[0036] In the present invention, the optional range of the type of the solvent is relatively wide. For illustrative purposes only, but not limiting the scope of the present invention thereby. According to a preferred embodiment of the present invention, the solvent is selected from water.

[0037] In the present invention, the range of the alginate that can be selected is relatively wide. For illustrative purposes only and without limiting the scope of the present invention thereby, according to a preferred embodiment of the present invention, the alginate is selected from one or more of sodium alginate, potassium alginate, magnesium alginate, and ammonium alginate.

[0038] The second aspect of the present invention provides a method for preparing the slurry described in the present invention. The method for preparing the slurry includes:

[0039] (1) After mixing activated carbon with a solvent, add alginate;

[0040] (2) Add an alkali to adjust the pH.

[0041] In the present invention, by adding an alkali to adjust the pH of the slurry, it is ensured that the dropping head is not blocked and the dropping of the balls can proceed continuously when preparing activated carbon particles by dropping ball forming, guaranteeing the smooth forming of the dropping ball particles during the preparation process and not easily blocking the dropping head. For alginate, under acidic conditions (lower than pK a ), the negatively charged carboxyl groups (-COO - ) on the side chains of alginate are prone to capturing hydrogen ions in the solution to become electrically neutral carboxyl groups (-COOH), thereby losing the side chain cross-linking and gelling performance. And depending on the source and processing method of the activated carbon, the surface charge situation is different, and it may be acidic in the water suspension system, thus deviating from the optimal gelling range of alginate. Therefore, adding an alkali to adjust the pH can effectively solve the problem that activated carbon cannot form a gel in the alginate system. On the other hand, the mixture of alginate and activated carbon needs to be mixed with another forming aid solution to form a gel, and the gelling mechanism is mainly the cross-linking reaction of alginate with specific metal ions. However, depending on the source of the activated carbon, it is easy to entrain various complex metal ions such as magnesium and calcium, resulting in the premature cross-linking reaction of alginate before contacting the forming aid. Therefore, within the pH range of the present invention, the negative effects of many metal ions on the gelling of alginate can be effectively shielded.

[0042] In the present invention, there is no particular limitation on the way of adding the alkali. For example, the pH can be adjusted by using an aqueous solution of the alkali.

[0043] The third aspect of the present invention provides a method for preparing activated carbon particles. The method includes:

[0044] (I) Drop the slurry described in the present invention into a forming aid with a dropping head, and obtain solidified particles by dropping ball forming; the forming aid is selected from a solution containing polyvalent metal cations, and the concentration of the metal cations is not less than 0.01 wt%.

[0045] (II) Separate, dry, and calcine the solidified particles to obtain activated carbon particles. The preparation method of the activated carbon particles of the present invention has the advantages of high product uniformity, easy availability of equipment, simple operation steps, etc., and is easy to realize industrial scale-up production, providing more activated carbon particle products for the chemical industry.

[0046] In the present invention, the types of forming aids can be selected from a relatively wide range. For illustrative purposes only and not to limit the scope of the present invention thereby, according to a preferred embodiment of the present invention, the forming aid is selected from solutions containing polyvalent metal cations, and the metals of the polyvalent metal cations are selected from one or more of aluminum, zinc, calcium, copper, iron, ferrous, cobalt, manganese, and nickel.

[0047] In the present invention, the sizes of the drip tips can be selected from a relatively wide range. For illustrative purposes only and not to limit the scope of the present invention thereby, according to a preferred embodiment of the present invention, the drip tip size is 0.2 - 5 mm.

[0048] In the present invention, the concentration range of metal ions can be selected from a relatively wide range. For illustrative purposes only and not to limit the scope of the present invention thereby, according to a preferred embodiment of the present invention, in the solution containing polyvalent metal cations, the concentration of metal ions is 0.01 - 10 wt%.

[0049] In the present invention, there is no particular limitation on the drying method, as long as the water is removed. According to a preferred embodiment of the present invention, the drying method is natural air drying or oven drying.

[0050] In the present invention, there is no particular limitation on the calcination conditions, and conventional calcination conditions in the art can be used for the present invention. According to a preferred embodiment of the present invention, calcination is carried out under anaerobic conditions, and the calcination conditions include: the temperature is 50 - 1200 °C, preferably 110 - 550 °C, and the time is 0.5 - 12 h, preferably 1 - 5 h.

[0051] In the present invention, as the anaerobic condition, calcination is carried out in an inert gas atmosphere. According to a preferred embodiment of the present invention, the inert gas is selected from one or more of nitrogen and noble gases.

[0052] According to a preferred embodiment of the present invention, the calcination method is gradient calcination: preferably, the temperature is raised to 80 - 130 °C at a heating rate of 0.1 - 20 °C / min and calcined for 30 - 240 min; then the temperature is raised to 300 - 400 °C at a heating rate of 0.1 - 20 °C / min and calcined for 5 - 60 min; finally, the temperature is raised to 500 - 800 °C at a heating rate of 0.1 - 20 °C / min and calcined for 60 - 600 min.

[0053] To further understand the present invention, the preferred embodiments of the present invention will be described below in conjunction with examples. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0054] To illustrate the present invention more clearly, the following examples are listed, but the applicable situations of the present invention are not limited to the scope of the examples.

[0055] Example 1

[0056] (1) Pass the activated carbon powder through a 200-mesh sieve. Add 20 g of the activated carbon powder to 80 ml of water, stir and mix evenly, and then add 0.5 g of sodium alginate to form a slurry.

[0057] (2) Add 1.6 mL of 20 wt% ammonia water to adjust the pH to 11, and stir for 1 h to mix evenly.

[0058] (3) Drop the mixture into a 4 wt% calcium chloride solution using droppers with diameters of 0.7 mm, 1.0 mm, and 1.2 mm respectively, stir to form solidified particles, fish them out after reacting for 0.5 h, and air-dry naturally.

[0059] (4) Put the dried particles into a muffle furnace for gradient calcination, and use nitrogen as the calcination atmosphere: 1) The calcination temperature rises from room temperature to 110 °C in 30 minutes, and the calcination time is maintained for 30 minutes; 2) The calcination temperature rises from 110 °C to 350 °C in 60 minutes, and the calcination time is maintained for 30 minutes; 3) The calcination temperature rises from 350 °C to 550 °C in 120 minutes, and the calcination time is maintained for 3 hours to obtain activated carbon particles.

[0060] Analyze the product: Droppers with diameters of 0.7 mm, 1.0 mm, and 1.2 mm can all successfully form spheres, and the spheroidizing performance is good.

[0061] Example 2

[0062] The implementation process is the same as that of Example 1, except that in step (2), 50 μL of 20 wt% ammonia water is added to adjust the pH to 10.

[0063] Analyze the product: Droppers with diameters of 0.7 mm, 1.0 mm, and 1.2 mm can all successfully form spheres, and the spheroidizing performance is good.

[0064] Example 3

[0065] The implementation process is the same as that of Example 1, except that the activated carbon is passed through an 80-mesh sieve.

[0066] Analyze the product: Droppers with diameters of 1.0 mm and 1.2 mm can both successfully form spheres, and the spheroidizing performance is good; the 0.7-mm dropper is slightly blocked when forming spheres.

[0067] Example 4

[0068] The implementation process is the same as that of Example 1, except that in step (1), the addition amount of activated carbon is 25 g; in step (3), the concentration of calcium chloride is 0.2 wt%; and the remaining conditions are the same as those of Example 1.

[0069] Analysis of the product: It can be smoothly dropped into balls, and the ball-forming performance is good.

[0070] Example 5

[0071] The implementation process is the same as that of Example 1, adding 0.1 mL of 0.1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, and the remaining conditions are the same as those of Example 1.

[0072] Analysis of the product: The droppers with three different sizes of 0.7 mm, 1.0 mm, and 1.2 mm can be smoothly dropped into balls, and the ball-forming performance is good.

[0073] Example 6

[0074] The implementation process is the same as that of Example 1, adding 200 μL of 0.5 mol / L sodium carbonate aqueous solution to adjust the pH to 10, and the remaining conditions are the same as those of Example 1.

[0075] Analysis of the product: The droppers with three different sizes of 0.7 mm, 1.0 mm, and 1.2 mm can be smoothly dropped into balls, and the ball-forming performance is good.

[0076] Example 7

[0077] (1) Pass the activated carbon powder through a 200-mesh sieve, add 13 g of activated carbon powder to 80 ml of water, stir and mix evenly, and add 2.5 g of sodium alginate to form a slurry;

[0078] (2) Add 20 wt% ammonia water to adjust the pH to 10, and stir for 1 h to mix evenly;

[0079] (3) Drop into 7 wt% zinc chloride solution respectively with droppers of 0.7 mm, 1.0 mm, and 1.2 mm, stir to form solidified particles, fish out after reacting for 0.5 h, and dry naturally;

[0080] (4) Put the dried particles into a muffle furnace for gradient calcination, and use nitrogen as the calcination atmosphere: 1) The calcination temperature rises from room temperature to 110 °C in 30 minutes, and the calcination time is maintained for 30 minutes; 2) The calcination temperature rises from 110 °C to 350 °C in 60 minutes, and the calcination time is maintained for 30 minutes; 3) The calcination temperature rises from 350 °C to 550 °C in 120 minutes, and the calcination time is maintained for 3 hours to obtain activated carbon particles.

[0081] Analyze the product: Droplets of three different sizes, 0.7 mm, 1.0 mm, and 1.2 mm, can all successfully form spheres, and the spheroidization performance is good.

[0082] Example 8

[0083] (1) Pass the activated carbon powder through a 200-mesh sieve. Add 5 g of activated carbon powder to 80 ml of water, stir and mix evenly, and then add 1.2 g of sodium alginate to form a slurry.

[0084] (2) Add triethylamine to adjust the pH to 8 and stir for 1 h to mix evenly.

[0085] (3) Drop the solution into a 10 wt% aluminum chloride solution using droppers with diameters of 0.7 mm, 1.0 mm, and 1.2 mm respectively, stir to form solidified particles, fish them out after reacting for 0.5 h, and dry them naturally.

[0086] (4) Put the dried particles into a muffle furnace for gradient calcination, using nitrogen as the calcination atmosphere: 1) The calcination temperature rises from room temperature to 110 °C in 30 minutes and is maintained for 30 minutes; 2) The calcination temperature rises from 110 °C to 350 °C in 60 minutes and is maintained for 30 minutes; 3) The calcination temperature rises from 350 °C to 550 °C in 120 minutes and is maintained for 3 hours to obtain activated carbon particles.

[0087] Analyze the product: Droplets of three different sizes, 0.7 mm, 1.0 mm, and 1.2 mm, can all successfully form spheres, and the spheroidization performance is good.

[0088] Comparative Example 1

[0089] The implementation process is the same as that of Example 1, except that ammonia water is not added to adjust the pH, and the pH of the slurry is 6.7; other conditions are the same as those of Example 1.

[0090] Analyze the product: It is difficult to form spheres. It is difficult to form spheres with a 1.2-mm dropper, and it is impossible to form spheres with other smaller-sized needles.

[0091] Comparative Example 2

[0092] The implementation process is the same as that of Example 1, except that the activated carbon is passed through a 300-mesh sieve and ammonia water is not added to adjust the pH, and the pH of the slurry is 6.7; other conditions are the same as those of Example 1.

[0093] Analyze the product: It is difficult to form spheres. It is already relatively difficult to form spheres with a 1.2-mm dropper, and it is impossible to form spheres with other smaller-sized needles.

[0094] Comparative Example 3

[0095] The implementation process is the same as that of Example 1, except that the amount of activated carbon used is 90 g, and other conditions are the same as those of Example 1.

[0096] At this time, when preparing the activated carbon slurry, the slurry was too viscous to be stirred.

[0097] Comparative Example 4

[0098] The implementation process was the same as that of Example 1, but first the alginate was mixed and dissolved with the solvent and then the activated carbon was added. Specifically:

[0099] (1) 0.5 g of sodium alginate was added to 80 ml of water, stirred and mixed evenly, and then 20 g of activated carbon was added and stirred;

[0100] (2) 20 wt% ammonia water was added to adjust the pH to 10, and stirred for 1 h to mix evenly;

[0101] The activated carbon could not be evenly dispersed in the slurry, obvious agglomeration occurred, and the subsequent operations could not be continued.

[0102] Comparative Example 5

[0103] The implementation process was the same as that of Example 1, except that the 4 wt% calcium chloride solution was replaced with a sodium chloride solution of the same concentration, and the other conditions were the same as those of Example 1.

[0104] At this time, when the activated carbon slurry was mixed with the forming aid, no colloidal spheres were formed, but it was directly dispersed.

[0105] Comparative Example 6

[0106] The implementation process was the same as that of Example 1, except that the 4 wt% calcium chloride solution was replaced with a 0.001 wt% calcium chloride solution, and the other conditions were the same as those of Example 1.

[0107] At this time, when the activated carbon slurry was mixed with the forming aid, no colloidal spheres were formed, and only a small amount of flocculants were formed.

[0108] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A slurry for forming activated carbon drip balls, characterized in that, based on the total weight of the slurry, the slurry comprises: solvent 50 - 99.5 wt%; activated carbon powder 0.1 - 50 wt%; alginic acid salt 0.01 - 10 wt%; the pH value of the slurry is 8 - 14.

2. The slurry according to claim 1, wherein, The slurry contains an alkali, and the alkali is selected from one or more of soluble hydroxides, soluble carbonates, soluble bicarbonates, NH 3 , NH 3 ·H 2 O, and organic amines having 1 to 6 carbon atoms; Preferably, the base is selected from one or more of NH 3 , NH 3 ·H 2 O, ammonium carbonate, ammonium bicarbonate, and C1-C6 organic amines; more preferably NH 3 ·H 2 O.

3. The slurry according to claim 2, wherein, the C1 - C6 organic amine is selected from one or more of methylamine, monoethylamine, diethylamine, ethylenediamine, propylamine, triethylamine, propylenediamine, butanediamine and hexanediamine.

4. The slurry according to claim 1 or 2, wherein, the mesh number of the sieved activated carbon powder is not less than 80 mesh, preferably not less than 200 mesh; and / or the alginic acid salt is selected from one or more of sodium alginate, potassium alginate, magnesium alginate, ammonium alginate; and / or the solvent is water.

5. A preparation method of the slurry according to any one of claims 1 - 4, characterized in that, the preparation method of the slurry comprises: (1) After mixing activated carbon with the solvent, then adding the alginic acid salt; (2) Adding an alkali to adjust the pH.

6. A preparation method of activated carbon particles, characterized in that, the method comprises: (I) Dropping the slurry according to any one of claims 1 - 4 into a forming aid with a dropper to form solidified particles by drip ball forming; the forming aid is selected from a solution containing polyvalent metal cations, and the concentration of the metal cations is not less than 0.01 wt%; (II) Separating, drying and calcining the solidified particles to obtain activated carbon particles.

7. The preparation method of activated carbon particles according to claim 6, wherein, the metal of the polyvalent metal cations is selected from one or more of aluminum, zinc, calcium, copper, iron, ferrous, cobalt, manganese and nickel.

8. The preparation method of activated carbon particles according to claim 6 or 7, wherein, the size of the dropper is 0.2 - 5 mm; and / or calcining under anaerobic conditions, and the calcining conditions include: the temperature is 50 - 1200 °C, and the time is 0.5 - 12 h.

9. The preparation method of activated carbon particles according to claim 7, wherein, in the solution containing polyvalent metal cations, the concentration of the metal cations is 0.01 - 10 wt%.

10. Activated carbon particles prepared by the preparation method of activated carbon particles according to any one of claims 6 - 9.