Preparation method of sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions

Abstract

The invention discloses a preparation method of a sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions. The method comprises the following steps: (1) putting a NaX molecular sieve into a beaker; (2) adding deionized water, stirring, and pouring out waste liquid after washing when the deionized water naturally settles; (3) adding deionized water again, repeating the step (2), and fully washing the molecular sieve; (4) drying the washed molecular sieve to obtain a molecular sieve to be modified; (5) putting the molecular sieve to be modified into a beaker, adding a sulfuric acid solution, and stirring at room temperature; (6) after stirring is completed and the molecular sieve is thoroughly settled, pouring out reaction waste liquid; (7) adding deionized water, stirring to fully wash the molecular sieve, and standing; (8) repeating the step (7) until the pH value of the washing liquid is 7; and (9) drying the washed molecular sieve to obtain the modified sulfonated X-type molecular sieve. The raw materials are low in cost, easy to synthesize and mold, and suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention relates to a molecular sieve, and in particular to a preparation method of a sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions. Background Art

[0002] As an important raw material for the traditional chemical industry and the new energy industry, monovalent cation resources have attracted much attention. Most of them are stored in seawater, salt lakes, etc., and the effective enrichment and separation of monovalent cations in them has become one of the most challenging projects today. Especially for the extraction of potassium ions and sodium ions in abundant seawater resources, the properties and structures of the two are similar, and it is very difficult to separate them. The concentration of sodium ions in seawater is more than twenty times that of potassium ions, and the enrichment of potassium ions has become an important step in the extraction of potassium elements. The hydration radius of sodium ions and potassium ions differs at the angstrom level. If you want to accurately screen them, you should control the size of the separation pores. The cost of means such as COF membranes that can reach the angstrom level is huge and is not suitable for industrial production. In addition, the waste liquid prepared by them is toxic and pollutes the environment. Summary of the invention

[0003] In order to make up for the defects of the prior art, the present invention provides a method for preparing a sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions. The method uses an X-type molecular sieve with a suitable pore size, the pore size of which is about 13 angstroms, and further modifies the pore size by sulfonating it to make it between the intermediate value of hydrated potassium ions and hydrated sodium ions, thereby achieving effective screening of potassium ions and sodium ions. The present invention has low raw material cost, is easy to synthesize and form, and is suitable for industrial large-scale production.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A method for preparing a sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions comprises the following steps:

[0006] Step (1) placing 40-60 g of industrial NaX molecular sieve in a beaker or placing it in a beaker after ball milling and sieving;

[0007] Step (2) adding deionized water 2 to 4 times the mass of the molecular sieve and stirring, waiting for natural sedimentation, pouring out the waste liquid after washing, controlling the stirring speed to 100 to 500 rpm for 5 to 15 min;

[0008] Step (3) re-add deionized water 2 to 4 times the mass of the molecular sieve, and repeat the above step (2) until there are no impurities in the deionized water and the molecular sieve is fully washed;

[0009] Step (4) drying the washed molecular sieve to obtain the molecular sieve to be modified, controlling the drying temperature to be 60 to 80° C. and the drying time to be 10 to 30 hours;

[0010] Step (5) placing the molecular sieve to be modified in a beaker, adding a sulfuric acid solution of 3 to 5 times the mass of the molecular sieve, stirring at room temperature, controlling the stirring speed to be 500 to 1000 rpm, the time to be 30 to 120 min, and the concentration of the sulfuric acid solution to be 0.1 to 1 mol / L;

[0011] After the stirring in step (6) is completed, the mixture is allowed to stand for 5 to 15 minutes, and after the molecular sieve is completely settled, the reaction waste liquid is poured out;

[0012] Step (7) adding deionized water 3 to 5 times the mass of the molecular sieve and stirring to fully wash the molecular sieve, letting it stand, testing the pH value of the washing solution, and controlling the stirring speed to 100 to 500 rpm for 5 to 15 min;

[0013] Step (8) Repeat the above step (7) until the pH of the washing solution is 7 and the molecular sieve is washed completely;

[0014] Step (9): pour out the washing liquid, dry the washed molecular sieve, and obtain the modified sulfonated X-type molecular sieve. The drying temperature is controlled to be 60 to 80° C. and the drying time is 20 to 30 hours.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The present invention uses industrialized NaX molecular sieve as raw material, which is low in cost. The molecular sieve is modified by wet method, which can achieve the purpose of modification at room temperature, is safe to operate, and is easy to synthesize.

[0017] 2. The present invention modifies the original pores of the NaX molecular sieve with sulfonic acid groups, changes the original pore size to an intermediate value between hydrated potassium ions and hydrated sodium ions, thereby achieving effective screening of potassium ions and sodium ions.

[0018] 3. The present invention also uses sulfuric acid as a raw material for sulfonation, wherein sufficient hydrogen ions can exist as cations to balance the negative charge in the molecular sieve, thereby exchanging most of the sodium ions in the molecular sieve so that it does not affect the subsequent ion screening process. In addition, hydrogen ions as cations to balance the charge can increase the original pore volume compared to sodium ions. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below in conjunction with the embodiments, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0020] Example 1

[0021] This embodiment provides a sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions. The sulfonated X-type molecular sieve is prepared from NaX-type molecular sieve, 0.5 mol L -1 The specific method is as follows:

[0022] Step (1) Place 50 g of industrial NaX molecular sieve in a 250 ml beaker.

[0023] Step (2) Add 200 ml of deionized water and stir on a stirring table at 200 rpm for 10 min. Remove the beaker, wait for it to settle naturally, and pour out the waste liquid after washing.

[0024] Step (3) Add 200 ml of deionized water again and repeat the above step (2) three times until there are no impurities in the deionized water and the molecular sieve is fully washed.

[0025] Step (4) Place the washed molecular sieve in a forced air drying oven and dry at 60° C. for 24 h until completely dry to obtain the molecular sieve to be modified.

[0026] Step (5) Place the molecular sieve to be modified in a 250 ml beaker, prepare a 0.5 mol / L sulfuric acid solution, add 200 ml to the beaker, place on a stirring table, and stir at 500 rpm for 60 min at room temperature.

[0027] After the stirring in step (6) is completed, the mixture is allowed to stand for 10 minutes, and after the molecular sieve is completely settled, the reaction waste liquid is poured out.

[0028] In step (7), add 200 ml of deionized water and stir on a stirring table at 200 rpm for 5 min to fully wash the molecular sieve. After stirring, remove the mixture and let it stand to test the pH value of the washing solution.

[0029] Step (8) Repeat the above step (7) until the pH of the washing solution after washing and sedimentation is 7, indicating that the molecular sieve is washed completely.

[0030] Step (9) Take part of the washing liquid, centrifuge it and test the sodium content therein by ICP, which proves that the sodium in the molecular sieve is completely exchanged.

[0031] Step (10): pour out the washing liquid, put the washed molecular sieve into a forced air drying oven, and dry it at 60° C. for 24 hours until it is completely dry, thereby obtaining a modified sulfonated X-type molecular sieve.

[0032] The molecular sieve of this embodiment was tested for performance. 50g of molecular sieve was placed in a zeolite exchange column with filter membranes placed above and below to prevent powder leakage. The solution was prepared according to the concentration of potassium ions and sodium ions in seawater and passed through the zeolite exchange column from top to bottom. Repeated three times, the exchanged solution was taken and an ICP test was performed. Most of the potassium ions were retained by the molecular sieve. The ratio of potassium ions to sodium ions in the molecular sieve was about 1:2.2, which was much higher than the ratio in seawater, achieving efficient enrichment of potassium ions.

[0033] Example 2

[0034] This embodiment provides a sulfonated X-type molecular sieve with a low degree of sulfonation for efficient screening of potassium ions and sodium ions. The sulfonated X-type molecular sieve is composed of NaX-type molecular sieve, 0.1 mol L -1 The specific method is as follows:

[0035] Step (1) Place 50 g of industrial NaX molecular sieve in a 250 ml beaker.

[0036] Step (2) Add 200 ml of deionized water and stir on a stirring table at 200 rpm for 10 min. Remove the beaker, wait for it to settle naturally, and pour out the waste liquid after washing.

[0037] Step (3) Add 200 ml of deionized water again and repeat the above step (2) three times until there are no impurities in the deionized water and the molecular sieve is fully washed.

[0038] Step (4) Place the washed molecular sieve in a forced air drying oven and dry at 60° C. for 24 h until completely dry to obtain the molecular sieve to be modified.

[0039] Step (5) Place the molecular sieve to be modified in a 250 ml beaker, prepare 0.1 mol / L sulfuric acid solution, add 200 ml into the beaker, place on a stirring table, and stir at 500 rpm for 60 min at room temperature.

[0040] After the stirring in step (6) is completed, the mixture is allowed to stand for 10 minutes, and after the molecular sieve is completely settled, the reaction waste liquid is poured out.

[0041] In step (7), add 200 ml of deionized water and stir on a stirring table at 200 rpm for 5 min to fully wash the molecular sieve. After stirring, remove the mixture and let it stand to test the pH value of the washing solution.

[0042] Step (8) Repeat the above step (7) until the pH of the washing solution after washing and sedimentation is 7, indicating that the molecular sieve is washed completely.

[0043] Step (9) Take part of the washing liquid, centrifuge it and test the sodium content therein by ICP, which proves that the sodium in the molecular sieve is completely exchanged.

[0044] Step (10): pour out the washing liquid, put the washed molecular sieve into a forced air drying oven, and dry it at 60° C. for 24 hours until it is completely dry, thereby obtaining a modified sulfonated X-type molecular sieve.

[0045] The molecular sieve of this embodiment was tested for performance. 50g of molecular sieve was placed in a zeolite exchange column with filter membranes placed above and below to prevent powder leakage. The solution was prepared according to the concentration of potassium ions and sodium ions in seawater and passed through the zeolite exchange column from top to bottom. Repeated three times, the exchanged solution was taken and an ICP test was performed. Most of the potassium ions were retained by the molecular sieve. The ratio of potassium ions to sodium ions in the molecular sieve was about 1:1.8, which was much higher than the ratio in seawater, achieving efficient enrichment of potassium ions.

[0046] Example 3

[0047] This embodiment provides a highly sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions. The sulfonated X-type molecular sieve is composed of NaX-type molecular sieve, 1 mol L -1 The specific method is as follows:

[0048] Step (1) Place 50 g of industrial NaX molecular sieve in a 250 ml beaker.

[0049] Step (2) Add 200 ml of deionized water and stir on a stirring table at 200 rpm for 10 min. Remove the beaker, wait for it to settle naturally, and pour out the waste liquid after washing.

[0050] Step (3) Add 200 ml of deionized water again and repeat the above step (2) three times until there are no impurities in the deionized water and the molecular sieve is fully washed.

[0051] Step (4) Place the washed molecular sieve in a forced air drying oven and dry at 60° C. for 24 h until completely dry to obtain the molecular sieve to be modified.

[0052] Step (5) Place the molecular sieve to be modified in a 250 ml beaker, prepare 1 mol / L sulfuric acid solution, add 200 ml into the beaker, place on a stirring table, and stir at 500 rpm for 60 min at room temperature.

[0053] After the stirring in step (6) is completed, the mixture is allowed to stand for 10 minutes, and after the molecular sieve is completely settled, the reaction waste liquid is poured out.

[0054] In step (7), add 200 ml of deionized water and stir on a stirring table at 200 rpm for 5 min to fully wash the molecular sieve. After stirring, remove the mixture and let it stand to test the pH value of the washing solution.

[0055] Step (8) Repeat the above step (7) until the pH of the washing solution after washing and sedimentation is 7, indicating that the molecular sieve is washed completely.

[0056] Step (9) Take part of the washing liquid, centrifuge it and test the sodium content therein by ICP, which proves that the sodium in the molecular sieve is completely exchanged.

[0057] Step (10): pour out the washing liquid, put the washed molecular sieve into a forced air drying oven, and dry it at 60° C. for 24 hours until it is completely dry, thereby obtaining a modified sulfonated X-type molecular sieve.

[0058] The molecular sieve of this embodiment was tested for performance. 50g of molecular sieve was placed in a zeolite exchange column with filter membranes placed above and below to prevent powder leakage. The solution was prepared according to the concentration of potassium ions and sodium ions in seawater and passed through the zeolite exchange column from top to bottom. Repeated three times, the exchanged solution was taken and an ICP test was performed. Most of the potassium ions were retained by the molecular sieve. The ratio of potassium ions to sodium ions in the molecular sieve was about 1:2.6, which was much higher than the ratio in seawater, achieving efficient enrichment of potassium ions.

[0059] Example 4

[0060] This embodiment provides a sulfonated X-type powder molecular sieve for efficiently screening potassium ions and sodium ions. The sulfonated X-type powder molecular sieve is composed of NaX-type molecular sieve, 0.5 mol L -1 The specific method is as follows:

[0061] Step (1) 50 g of industrial NaX molecular sieve was placed in a ball mill for ball milling, and after grinding and sieving, the sieve was placed in a 250 ml beaker.

[0062] Step (2) Add 200 ml of deionized water and stir on a stirring table at 200 rpm for 10 min. Remove the beaker, wait for it to settle naturally, and pour out the waste liquid after washing.

[0063] Step (3) Add 200 ml of deionized water again and repeat the above step (2) three times until there are no impurities in the deionized water and the molecular sieve is fully washed.

[0064] Step (4) Place the washed molecular sieve in a forced air drying oven and dry at 60° C. for 24 h until completely dry to obtain the molecular sieve to be modified.

[0065] Step (5) Place the molecular sieve to be modified in a 250 ml beaker, prepare a 0.5 mol / L sulfuric acid solution, add 200 ml to the beaker, place on a stirring table, and stir at 500 rpm for 60 min at room temperature.

[0066] After the stirring in step (6) is completed, the mixture is allowed to stand for 10 minutes, and after the molecular sieve is completely settled, the reaction waste liquid is poured out.

[0067] In step (7), add 200 ml of deionized water and stir on a stirring table at 200 rpm for 5 min to fully wash the molecular sieve. After stirring, remove the mixture and let it stand to test the pH value of the washing solution.

[0068] Step (8) Repeat the above step (7) until the pH of the washing solution after washing and sedimentation is 7, indicating that the molecular sieve is washed completely.

[0069] Step (9) Take part of the washing liquid, centrifuge it and test the sodium content therein by ICP, which proves that the sodium in the molecular sieve is completely exchanged.

[0070] Step (10): pour out the washing liquid, put the washed molecular sieve into a forced air drying oven, and dry it at 60° C. for 24 hours until it is completely dry, thereby obtaining a modified sulfonated X-type powder molecular sieve.

[0071] The molecular sieve of this embodiment was tested for performance. 50g of molecular sieve was placed in a zeolite exchange column with filter membranes placed above and below to prevent powder leakage. The solution was prepared according to the concentration of potassium ions and sodium ions in seawater and passed through the zeolite exchange column from top to bottom. This was repeated three times, and the exchanged solution was taken. Most of the potassium ions were retained by the molecular sieve. The ratio of potassium ions to sodium ions in the molecular sieve was about 1:2.8, which was much higher than the ratio in seawater, achieving efficient enrichment of potassium ions.

[0072] Example 5

[0073] This embodiment provides a sulfonated X-type powder molecular sieve with a low degree of sulfonation for efficient screening of potassium ions and sodium ions. The sulfonated X-type powder molecular sieve is composed of NaX-type molecular sieve, 0.1 mol L -1 The specific method is as follows:

[0074] Step (1) 50 g of industrial NaX molecular sieve was placed in a ball mill for ball milling, and after grinding and sieving, the sieve was placed in a 250 ml beaker.

[0075] Step (2) Add 200 ml of deionized water and stir on a stirring table at 200 rpm for 10 min. Remove the beaker, wait for it to settle naturally, and pour out the waste liquid after washing.

[0076] Step (3) Add 200 ml of deionized water again and repeat the above step (2) three times until there are no impurities in the deionized water and the molecular sieve is fully washed.

[0077] Step (4) Place the washed molecular sieve in a forced air drying oven and dry at 60° C. for 24 h until completely dry to obtain the molecular sieve to be modified.

[0078] Step (5) Place the molecular sieve to be modified in a 250 ml beaker, prepare 0.5 mol / L sulfuric acid solution, add 200 ml into the beaker, place on a stirring table, and stir at 500 rpm for 60 min at room temperature.

[0079] After the stirring in step (6) is completed, the mixture is allowed to stand for 10 minutes, and after the molecular sieve is completely settled, the reaction waste liquid is poured out.

[0080] In step (7), add 200 ml of deionized water and stir on a stirring table at 200 rpm for 5 min to fully wash the molecular sieve. After stirring, remove the mixture and let it stand to test the pH value of the washing solution.

[0081] Step (8) Repeat the above step (7) until the pH of the washing solution after washing and sedimentation is 7, indicating that the molecular sieve is washed completely.

[0082] Step (9) Take part of the washing liquid, centrifuge it and test the sodium content therein by ICP, which proves that the sodium in the molecular sieve is completely exchanged.

[0083] Step (10): pour out the washing liquid, put the washed molecular sieve into a forced air drying oven, and dry it at 60° C. for 24 hours until it is completely dry, thereby obtaining a modified sulfonated X-type powder molecular sieve.

[0084] The molecular sieve of this embodiment was tested for performance. 50g of molecular sieve was placed in a zeolite exchange column with filter membranes placed above and below to prevent powder leakage. The solution was prepared according to the concentration of potassium ions and sodium ions in seawater and passed through the zeolite exchange column from top to bottom. Repeated three times, the exchanged solution was taken and an ICP test was performed. Most of the potassium ions were retained by the molecular sieve. The ratio of potassium ions to sodium ions in the molecular sieve was about 1:3.6, which was much higher than the ratio in seawater, achieving efficient enrichment of potassium ions.

[0085] Example 6

[0086] This embodiment provides a sulfonated X-type powder molecular sieve with a high degree of sulfonation for efficient screening of potassium ions and sodium ions. The sulfonated X-type powder molecular sieve is composed of NaX-type molecular sieve, 1 mol L -1 The specific method is as follows:

[0087] Step (1) 50 g of industrial NaX molecular sieve was placed in a ball mill for ball milling, and after grinding and sieving, the sieve was placed in a 250 ml beaker.

[0088] Step (2) Add 200 ml of deionized water and stir on a stirring table at 200 rpm for 10 min. Remove the beaker, wait for it to settle naturally, and pour out the waste liquid after washing.

[0089] Step (3) Add 200 ml of deionized water again and repeat the above step (2) three times until there are no impurities in the deionized water and the molecular sieve is fully washed.

[0090] Step (4) Place the washed molecular sieve in a forced air drying oven and dry at 60° C. for 24 h until completely dry to obtain the molecular sieve to be modified.

[0091] Step (5) Place the molecular sieve to be modified in a 250 ml beaker, prepare 1 mol / L sulfuric acid solution, add 200 ml into the beaker, place on a stirring table, and stir at 500 rpm for 60 min at room temperature.

[0092] After the stirring in step (6) is completed, the mixture is allowed to stand for 10 minutes, and after the molecular sieve is completely settled, the reaction waste liquid is poured out.

[0093] In step (7), add 200 ml of deionized water and stir on a stirring table at 200 rpm for 5 min to fully wash the molecular sieve. After stirring, remove the mixture and let it stand to test the pH value of the washing solution.

[0094] Step (8) Repeat the above step (7) until the pH of the washing solution after washing and sedimentation is 7, indicating that the molecular sieve is washed completely.

[0095] Step (9) Take part of the washing liquid, centrifuge it and test the sodium content therein by ICP, which proves that the sodium in the molecular sieve is completely exchanged.

[0096] Step (10): pour out the washing liquid, put the washed molecular sieve into a forced air drying oven, and dry it at 60° C. for 24 hours until it is completely dry, thereby obtaining a modified sulfonated X-type powder molecular sieve.

[0097] The molecular sieve of this embodiment was tested for performance. 50g of molecular sieve was placed in a zeolite exchange column with filter membranes placed above and below to prevent powder and leakage. The solution was prepared according to the concentration of potassium ions and sodium ions in seawater and passed through the zeolite exchange column from top to bottom. Repeated three times, the exchanged solution was taken, and the ICP test was performed. Most of the potassium ions were retained by the molecular sieve. The ratio of potassium ions to sodium ions in the molecular sieve was about 1:3.6, which was much higher than the ratio in seawater, achieving efficient enrichment of potassium ions.

Claims

1. A method for preparing a sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions, characterized in that The method comprises the following steps: Step (1) placing industrial NaX molecular sieve in a beaker or placing the ball-milled and sieved NaX molecular sieve in a beaker; Step (2) adding deionized water and stirring, allowing it to settle naturally, and pouring out the waste liquid after washing; Step (3) re-add deionized water and repeat the above step (2) until there are no impurities in the deionized water and the molecular sieve is fully washed; Step (4) drying the washed molecular sieve to obtain the molecular sieve to be modified; Step (5) placing the molecular sieve to be modified in a beaker, adding sulfuric acid solution, and stirring at room temperature; After the stirring in step (6) is completed, the mixture is allowed to stand for a while until the molecular sieve is completely settled, and then the reaction waste liquid is poured out; Step (7) adding deionized water and stirring to fully wash the molecular sieve, allowing the mixture to stand, and testing the pH value of the washing solution; Step (8) Repeat the above step (7) until the pH of the washing solution is 7 and the molecular sieve is washed completely; Step (9) Pour out the washing liquid, dry the washed molecular sieve, and obtain the modified sulfonated X-type molecular sieve.

2. The method for preparing the sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions according to claim 1, characterized in that In the step (2), the amount of deionized water added is 2 to 4 times the mass of the molecular sieve, the stirring speed is 100 to 500 rpm, and the time is 5 to 15 min.

3. The method for preparing the sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions according to claim 1, characterized in that In the step (3), the amount of deionized water added is 2 to 4 times the mass of the molecular sieve.

4. The method for preparing the sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions according to claim 1, characterized in that In the step (4), the drying temperature is 60 to 80° C. and the drying time is 10 to 30 hours.

5. The method for preparing the sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions according to claim 1, characterized in that In the step (5), the amount of sulfuric acid solution added is 3 to 5 times the mass of the molecular sieve, the concentration of the sulfuric acid solution is 0.1 to 1 mol / L, the stirring speed is 500 to 1000 rpm, and the time is 30 to 120 min.

6. The method for preparing the sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions according to claim 1, characterized in that In the step (6), the standing time is 5 to 15 minutes.

7. The method for preparing the sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions according to claim 1, characterized in that In the step (7), the amount of deionized water added is 3 to 5 times the mass of the molecular sieve, the stirring speed is 100 to 500 rpm, and the stirring time is 5 to 15 min.

8. The method for preparing the sulfonated X-type molecular sieve for efficiently screening potassium ions and sodium ions according to claim 1, characterized in that In the step (9), the drying temperature is controlled to be 60-80° C. and the drying time is 20-30 hours.