Spherical activated carbon prepared from waste resin and preparation method thereof

Abstract

The application discloses spherical activated carbon prepared from waste resin and a preparation method thereof. The method comprises the following steps: mixing waste ion exchange resin with an aqueous solution containing a polyhydroxy compound and a soluble salt, drying, carbonizing, acid washing and water washing to obtain the spherical activated carbon. The preparation process is simple, and the waste resin solid waste is converted into high-value spherical activated carbon through one-step modification.

Description

Technical Field

[0001] This application relates to a spherical activated carbon prepared from waste resin and its preparation method, belonging to the field of materials preparation. Background Technology

[0002] Adsorption separation materials are polymeric materials that achieve separation, purification, concentration, and enrichment of substances through ion exchange and adsorption. They are widely used in industries such as industrial water treatment, food and drinking water, nuclear industry, electronics, biomedicine, environmental protection, and hydrometallurgy. Currently, widely used adsorption separation materials mainly include ion exchange resins, adsorption resins, chelating resins, and enzyme carrier resins.

[0003] Ion exchange resins were first applied in industrial water treatment. After decades of development, general industrial water treatment has become a standard area with large-scale and mature resin usage. Currently, ion exchange and adsorption resins still account for about 70% of applications in general industrial water treatment. The widespread use of ion exchange and adsorption resins in general industrial water treatment is mainly because impurity ions in water, at high temperatures, will form insoluble substances such as calcium carbonate, calcium sulfate, magnesium hydroxide, and magnesium silicate, which deposit on the boiler heating surfaces to form scale. This scale causes bulging and pitting on the heating surfaces, leading to the rupture of boiling tubes and vertical pipes. This not only endangers the safe operation of the boiler but also increases boiler maintenance costs. Therefore, the water entering the boiler must have both impurity cations and anions removed.

[0004] In 2021, my country's ion exchange resin production capacity was 470,000 tons, output was 356,000 tons, up 7.6% year-on-year, imports were 18,000 tons, up 10.8% year-on-year, exports were 129,000 tons, up 13.7% year-on-year, and domestic apparent consumption of ion exchange resin was 245,000 tons, up 4.8% year-on-year.

[0005] However, used ion exchange resins contain organic matter or heavy metal ions, becoming hazardous solid waste. Traditional methods for treating this type of solid waste include incineration or landfill, but these methods easily cause secondary pollution and result in significant resource waste. Therefore, effectively converting waste ion exchange resins into resources is of great importance. Summary of the Invention

[0006] According to one aspect of this application, a method for preparing spherical activated carbon using waste resin is provided. The waste ion exchange resin solid waste is modified in one step and transformed into high-value spherical activated carbon, which solves the problem that the traditional treatment methods of ion exchange resin solid waste, such as incineration or landfill, are prone to secondary pollution and cause a large amount of resource waste.

[0007] The technical solution adopted in this application is as follows:

[0008] A method for preparing spherical activated carbon using waste resin includes the following steps:

[0009] Waste ion exchange resin was mixed with an aqueous solution containing polyhydroxy compounds and soluble salts, dried, and carbonized to obtain a spherical activated carbon precursor.

[0010] The spherical activated carbon precursor was acid-washed and water-washed to obtain the spherical activated carbon.

[0011] Optionally, the waste ion exchange resin is selected from at least one of waste sulfonic acid type ion exchange resin, waste carboxylic acid type ion exchange resin, and waste quaternary ammonium salt type ion exchange resin.

[0012] Optionally, the polyhydroxy compound is selected from at least one of glucose, sucrose, glycerol, sorbitol, and ascorbic acid;

[0013] The content of polyhydroxy compounds in the aqueous solution is 5-50 wt%.

[0014] The content of the polyhydroxy compound in the aqueous solution is selected from any value of 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 4wt%, 45wt%, 50wt%, or any range between the two.

[0015] Optionally, the soluble salt is selected from at least one of zinc chloride, zinc sulfate, sodium chloride, sodium sulfate, magnesium chloride, magnesium sulfate, potassium carbonate, and potassium sulfate;

[0016] The aqueous solution contains 1–20 wt% soluble salts.

[0017] The content of soluble salts in the aqueous solution is selected from any value of 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 10wt%, 15wt%, 20wt%, or any range between the two.

[0018] Optionally, the solid-liquid mass ratio of the waste ion exchange resin to the aqueous solution containing polyhydroxy compounds and soluble salts is 0.1 to 2:1.

[0019] Optionally, the solid-liquid mass ratio of the waste ion exchange resin to the aqueous solution containing polyhydroxy compounds and soluble salts is selected from any value among 0.1:1, 0.2:1, 0.3:1, 0.41, 0.5:1, 1:1, 1.5:1, and 2:1, or any range between the two.

[0020] Optionally, the drying conditions include a temperature of 80–180°C and a time of 1–24 hours.

[0021] Optionally, the carbonization conditions include:

[0022] The carbonization is carried out in an inert gas atmosphere, with a carbonization temperature of 500–1200℃ and a carbonization time of 1–12 hours.

[0023] Optionally, the inactive gas atmosphere is selected from at least one of nitrogen, argon, and helium.

[0024] Optionally, the carbonization temperature is selected from any value among 500℃, 600℃, 700℃, 800℃, 900℃, 1000℃, 1100℃, and 1200℃, or a range between any two.

[0025] Optionally, the pickling conditions include a temperature of 0–150°C.

[0026] Optionally, the pickling conditions include any value of 0℃, 10℃, 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, or 50℃, or a range between any two.

[0027] The acid used for pickling is selected from at least one of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, and chloroacetic acid.

[0028] Optionally, in the pickling process, the weight ratio of the spherical activated carbon precursor to the acid is 1:1 to 5.

[0029] According to another aspect of this application, spherical activated carbon prepared by the above method is also provided, wherein the particle size of the spherical activated carbon is 0.1 to 1.2 mm;

[0030] The specific surface area of ​​the spherical activated carbon is 500–1500 m². 2 / g.

[0031] The beneficial effects that this application can produce include:

[0032] The preparation process is simple, transforming waste ion exchange resins into high-value spherical activated carbon with good specific surface area through one-step modification. Attached Figure Description

[0033] Figure 1 This is a photograph of the spherical activated carbon obtained in Example 1.

[0034] Figure 2 The nitrogen physical adsorption curve is shown for the spherical activated carbon obtained in Example 1. Detailed Implementation

[0035] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0036] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0037] Example 1

[0038] S1: Dissolve 10g glucose and 5g anhydrous sodium chloride in 20mL deionized water to obtain a homogeneous and transparent solution;

[0039] S2: Mix 20g of waste carboxylic acid ion exchange resin with the solution obtained in S1, and then dry at 120℃ to obtain modified waste resin dry balls;

[0040] S3: The modified waste resin dry balls are heated to 600℃ in a nitrogen atmosphere and kept at the temperature for 2 hours to obtain spherical activated carbon precursor.

[0041] S4: Wash the spherical activated carbon precursor twice with 2 times the amount of 10% HCl solution at 60℃, then wash with deionized water until neutral, and dry at 120℃ to obtain spherical activated carbon.

[0042] Figure 1 This is a photograph of the spherical activated carbon obtained in Example 1. Figure 2 The nitrogen physical adsorption curve is shown for the spherical activated carbon obtained in Example 1.

[0043] The obtained spherical activated carbon had an average particle size of 0.68 mm and a specific surface area of ​​1079 m². 2 / g.

[0044] Examples 2-5

[0045] It is basically the same as Example 1, except that glucose in S1 is replaced with sucrose, glycerol, sorbitol and ascorbic acid in sequence. Otherwise, it is exactly the same as Example 1.

[0046] The spherical activated carbon obtained in Examples 2-5 had an average particle size of 0.72 mm and a specific surface area of ​​1055 m². 2 / g.

[0047] Examples 6-7

[0048] It is basically the same as Example 1, except that the sodium chloride in S1 is replaced with zinc sulfate and potassium carbonate in turn. Otherwise, it is exactly the same as Example 1.

[0049] The spherical activated carbons obtained in Examples 6 and 7 had average particle sizes of 0.75 mm and 0.70 mm, respectively, and a specific surface area of ​​988 m². 2 / g and 1231m 2 / g.

[0050] Example 8

[0051] It is basically the same as Example 1, except that the amount of glucose in S1 is adjusted to 20g, and the rest is exactly the same as Example 1.

[0052] The obtained spherical activated carbon had an average particle size of 0.83 mm and a specific surface area of ​​1038 m². 2 / g.

[0053] Example 9

[0054] It is basically the same as Example 1, except that the amount of sodium chloride in S1 is adjusted to 1g, and the rest is exactly the same as Example 1.

[0055] The obtained spherical activated carbon had an average particle size of 0.65 mm and a specific surface area of ​​635 m². 2 / g.

[0056] Examples 10-11

[0057] The process is basically the same as in Example 1, except that the waste carboxylic acid ion exchange resin in S2 is replaced with waste sulfonic acid ion exchange resin and waste quaternary ammonium salt ion exchange resin in sequence. Otherwise, it is exactly the same as in Example 1.

[0058] The average particle sizes of the obtained spherical activated carbon were 1.16 mm and 0.42 mm, respectively, and the specific surface areas were 1228 m², respectively. 2 / g and 774m 2 / g.

[0059] Example 12

[0060] It is basically the same as Example 1, except that the amount of waste ion exchange resin in S2 is adjusted to 40g, and the rest is exactly the same as Example 1.

[0061] The obtained spherical activated carbon had an average particle size of 0.60 mm and a specific surface area of ​​856 m². 2 / g.

[0062] Example 13

[0063] It is basically the same as Example 1, except that the carbonization temperature in S3 is adjusted to 1000°C. Otherwise, it is exactly the same as Example 1.

[0064] The obtained spherical activated carbon had an average particle size of 0.58 mm and a specific surface area of ​​1483 m². 2 / g.

[0065] Example 14

[0066] It is basically the same as Example 1, except that the HCl in S4 is changed to chloroacetic acid. Otherwise, it is exactly the same as Example 1.

[0067] The obtained spherical activated carbon had an average particle size of 0.70 mm and a specific surface area of ​​1091 m². 2 / g.

[0068] Example 15

[0069] It is basically the same as Example 1, except that the pickling temperature in S4 is adjusted to 0°C, and the rest is exactly the same as Example 1.

[0070] The obtained spherical activated carbon had an average particle size of 0.66 mm and a specific surface area of ​​971 m². 2 / g.

[0071] Comparative Example 1

[0072] It is basically the same as Example 1, except that glucose is not added. Otherwise, it is exactly the same as Example 1.

[0073] Spherical activated carbon could not be obtained in Comparative Example 1; only irregular blocky activated carbon was obtained, with a specific surface area of ​​583 m². 2 / g.

[0074] Comparative Example 2

[0075] It is basically the same as Example 1, except that sodium chloride is not added. Otherwise, it is exactly the same as Example 1.

[0076] The obtained spherical activated carbon had an average particle size of 0.64 mm and a specific surface area of ​​357 m². 2 / g.

[0077] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing spherical activated carbon using waste resin, characterized in that, The steps include the following: Waste ion exchange resin was mixed with an aqueous solution containing polyhydroxy compounds and soluble salts, dried, and carbonized to obtain a spherical activated carbon precursor. The polyhydroxy compound is selected from at least one of glucose, sucrose, glycerol, sorbitol, and ascorbic acid; The content of polyhydroxy compounds in the aqueous solution is 5-50 wt%; The soluble salt is selected from at least one of zinc chloride, zinc sulfate, sodium chloride, sodium sulfate, magnesium chloride, magnesium sulfate, potassium carbonate, and potassium sulfate. The soluble salt content in the aqueous solution is 1~20wt%; The spherical activated carbon precursor was acid-washed and water-washed to obtain the spherical activated carbon.

2. The method according to claim 1, characterized in that, The waste ion exchange resin is selected from at least one of waste sulfonic acid type ion exchange resin, waste carboxylic acid type ion exchange resin, and waste quaternary ammonium salt type ion exchange resin.

3. The method according to claim 1, characterized in that, The aqueous solution contains 25-45 wt% polyhydroxy compounds.

4. The method according to claim 1, characterized in that, The soluble salt is selected from at least one of zinc sulfate, sodium chloride, and potassium carbonate; The aqueous solution contains 3-15 wt% soluble salts.

5. The method according to claim 1, characterized in that, The solid-liquid mass ratio of the waste ion exchange resin to the aqueous solution containing polyhydroxy compounds and soluble salts is 0.1~2:

1.

6. The method according to claim 1, characterized in that, The drying conditions include a temperature of 80~180℃ and a time of 1~24 h.

7. The method according to claim 1, characterized in that, The carbonization conditions include: The carbonization is carried out in a non-reactive gas atmosphere, with a carbonization temperature of 500~1200 ℃ and a carbonization time of 1~12 h; The inactive gas is selected from at least one of nitrogen, argon, and helium.

8. The method according to claim 1, characterized in that, The pickling conditions include a temperature of 0~150℃; The acid used for pickling is selected from at least one of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, and chloroacetic acid.

9. The method according to claim 8, characterized in that, In the pickling process, the weight ratio of the spherical activated carbon precursor to the acid is 1:1 to 5.

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