Adsorbent and method for synchronous separation of rubidium and cesium in weak carbonic acid type salt lake brine

Abstract

The application discloses a new adsorbent and a new method for separating and extracting rubidium and cesium by using the new adsorbent, and can realize efficient separation of rubidium and cesium in weak carbonic acid type salt lake brine. The method can realize synchronous separation of rubidium and cesium and other coexisting ions in the weak carbonic acid type salt lake brine, has high separation efficiency, and the yield can reach more than 80%. Moreover, the adsorbent can be repeatedly activated, and the stability is good in multiple cycles.

Description

Technical Field

[0001] This invention belongs to the field of inorganic chemistry technology, specifically relating to an adsorbent and a method for simultaneous separation of rubidium and cesium in weakly carbonated salt lake brine. Background Technology

[0002] Rubidium and cesium resources in salt lake brines are not currently being utilized on a large scale. The extraction and utilization of rubidium and cesium resources is on the rise, with the main focus on extraction and membrane separation. However, there is little research on the process of enriching rubidium and cesium using natural energy and separating them from other coexisting ions. Existing technologies mainly focus on the enrichment and separation of potassium and lithium resources, without taking into account rubidium and cesium resources.

[0003] In weakly carbonated brine, potassium, rubidium, and cesium coexist, and because they are in the same periodic table, their properties are similar. Therefore, rubidium and cesium are enriched during natural evaporation. After reaching saturation, cesium enrichment becomes difficult, and complex potassium, rubidium, and cesium solid solutions are formed, making the separation and extraction of rubidium and cesium resources extremely difficult. To date, there are no mature case studies to refer to. Furthermore, due to the low abundance of trace elements in weakly carbonated brine, existing technologies suffer from low yields, difficulty in enrichment, and significant entrainment losses during separation, making the separation and extraction of rubidium and cesium from weakly carbonated brine extremely challenging.

[0004] In existing technologies, most adsorbents are heteropolyacids / ferrocyanides, which suffer from severe solubility loss and sulfate poisoning. This results in short adsorbent lifespan and a rapid decline in adsorption efficiency over time. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a novel adsorbent and uses this novel adsorbent to design a new method for separating and extracting rubidium and cesium. It can achieve efficient separation of rubidium and cesium in weakly carbonated salt lake brines. Using the method of this invention, rubidium and cesium in weakly carbonated salt lake brines can be separated from other coexisting ions simultaneously. The separation efficiency is high, and the yield can reach more than 80%. Moreover, the adsorbent can be regenerated and activated multiple times, and its stability remains good in multiple cycles.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a compound having the structural formula shown in Formula I: A n [B2(CN2) m ] (I), Where A is one or two of Na, K, Mg, and Ca. B is either Al or Fe. n is 1, 2 or 3, m is 2 or 4; CN2 is a cyano group.

[0007] Optionally, A is one of Na, K, Mg, and Ca.

[0008] In a second aspect, the present invention provides an application of the compound described in the first aspect as an adsorbent.

[0009] Thirdly, the present invention provides a method for simultaneous separation of rubidium and cesium in weakly carbonated brine, comprising the following steps: S1. Take a certain amount of brine and evaporate it at room temperature until the concentrations of rubidium and cesium are both greater than 300 mg / L, then stop evaporation to obtain brine enriched with rubidium and cesium. K in the brine + The content is 0.19~0.25 wt.%, Mg 2+ Content is 0.04~0.08 wt.%; Cl - The content is 1.20~1.30 wt.%; SO4 2- Content was 1.90~2.10 wt.%; CO3 2- The content is 0.25~0.28 wt.%; Rb + Content is 0.00060~0.00080 wt.%; Cs + The content is 0.0008~0.0010 wt.%; K in brine enriched with rubidium and cesium + The content is 4.00~4.50 wt.%; Mg 2+ The content is 0.80~0.93 wt.%; Cl - The content is 17.00~18.00 wt.%; SO4 2- Content was 5.82~6.10 wt.%; CO3 2- Content was 1.20~1.30 wt.%; Rb + The content is 0.0300~0.0389 wt.%; Cs + The content is 0.0300~0.0535 wt.%; S2, the rubidium- and cesium-enriched brine is mixed with an adsorbent to obtain a first mixture for adsorption process, wherein the volume ratio of the rubidium- and cesium-enriched brine to the adsorbent in the first mixture is 28:1 to 40:1. The adsorbent is the compound described in the first aspect; The structural formula of the compound is shown in Formula I: A n [B2(CN2) m ] (I), Where A is one or two of Na, K, Mg, and Ca. B is either Al or Fe. n is 1, 2 or 3, m is 2 or 4; CN2 is a cyano group; Optionally, A is one of Na, K, Mg, and Ca; Optionally, the first mixture is stirred during the adsorption process; S3, the first mixture that has completed the adsorption process is subjected to solid-liquid separation to obtain the liquid phase as the adsorption tail liquid and the solid phase as the adsorbent that has adsorbed rubidium and cesium. S4, the adsorbent that has adsorbed rubidium and cesium is mixed with dilute hydrochloric acid to obtain a second mixture for desorption process, wherein the volume ratio of the adsorbent that has adsorbed rubidium and cesium to the dilute hydrochloric acid in the second mixture is 1:1 to 2:1; and the concentration of the dilute hydrochloric acid is 0.2 to 0.5 M. Optionally, the second mixture is stirred during the desorption process; S5, the second mixture that has completed the desorption process is subjected to solid-liquid separation to obtain a liquid phase which is a first high rubidium and cesium content solution, and a solid phase which is the desorbed adsorbent.

[0010] In the above technical solution, in S2, the stirring rate is not greater than 200 rpm and the stirring time is not less than 5 hours.

[0011] In the above technical solution, in S3, the stirring rate is not greater than 200 rpm and the stirring time is not less than 2 hours.

[0012] In the above technical solution, the adsorption tail liquid is returned to step 1 as a brine raw material for reuse.

[0013] The above technical solution also includes step S6, which involves mixing the desorbed adsorbent with a sodium chloride solution to obtain a third mixture for regeneration. The volume ratio of the desorbed adsorbent to the sodium chloride solution in the third mixture is 1:0.8~1; the concentration of the sodium chloride solution is 5.0wt%~20.0wt%. Optionally, the third mixture is stirred during the regeneration process; The third mixture after the regeneration process is subjected to solid-liquid separation. The liquid phase is the regenerated liquid, which is mixed with the first high rubidium and cesium content solution in S5 to obtain the second high rubidium and cesium content solution. The resulting solid phase is the regenerated adsorbent, which is returned to step S2 for reuse.

[0014] In the above technical solution, in S6, the stirring rate is not greater than 200 rpm and the stirring time is not less than 0.5 h.

[0015] In the above technical solution, K in the adsorption tail liquid + The content is 4.00~4.50 wt.%; Mg 2+The content is 0.80~0.93 wt.%; Cl - The content is 17.00~18.00 wt.%; SO4 2- Content was 5.82~6.10 wt.%; CO3 2- Content was 1.20~1.30 wt.%; Rb + The content is 0.0010~0.0019 wt.%; Cs + The content is 0.0015~0.0018 wt.%; K in the first high rubidium cesium content solution + The content is 0.002~0.004 wt.%; Mg 2+ The content is 0.001~0.002 wt.%; Cl - The content is 11.03~11.68 wt.%; SO4 2- Content is 0.001~0.002 wt.%; CO3 2- Content is 0.001~0.002 wt.%; Rb + The content is 0.0244~0.0541 wt.%; Cs + The content is 0.0320~0.0730 wt.%.

[0016] K in the regenerated liquid + The content is 0.001~0.002 wt.%; Mg 2+ The content is 0.001~0.002 wt.%; Cl - The content is 2.91~3.21 wt.%; SO4 2- Content is 0.001~0.002 wt.%; CO3 2- Content is 0.001~0.002 wt.%; Rb + The content is 0.00321~0.0031 wt.%; Cs + The content is 0.0017~0.0027 wt.%.

[0017] The advantages and beneficial effects of this invention are as follows: 1) Room temperature evaporation: The evaporation method used is room temperature. This method has relatively wide requirements for the evaporation environment, is easy to operate and implement, does not consume too much energy, and the concentration ratio is controlled between 3.7 and 6.0.

[0018] 2) Evaporation control node is based on rubidium and cesium concentration: evaporation stops when the concentrations of both rubidium and cesium are greater than 300 mg / L. This data is based on the fact that the adsorbent can efficiently adsorb rubidium and cesium at concentrations greater than 300 mg / L.

[0019] 3) The adsorbent is environmentally friendly and can be recycled, with an adsorption capacity of over 300 mg / L.

[0020] 4) An "evaporation-adsorption" coupled method was constructed to separate rubidium and cesium in weakly carbonated salt lake brines.

[0021] The rubidium and cesium-enriched brine was further separated from other coexisting ions using adsorption. For the first time, a complete rubidium and cesium separation process was established specifically for weakly carbonated salt lake brines, which exhibit alkaline pH and present significant challenges in separating alkali metal ions. This method achieved a brine concentration factor of 5.6–6.2 times, a rubidium enrichment factor of 5.0–5.9 with a yield greater than 80%, and a cesium enrichment factor of 3.6–4.5 with a yield greater than 55%. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0023] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels. Example 1

[0024] Sodium ferricyanide and water are mixed in a mass ratio of 1:4 to form solution R1; potassium ferricyanide and water are mixed in a mass ratio of 1:5 to form solution R2; magnesium ferricyanide and water are mixed in a mass ratio of 1:6 to form solution R3; calcium ferricyanide and water are mixed in a mass ratio of 1:5 to form solution R4.

[0025] Sodium aluminum cyanide and water are mixed in a mass ratio of 1:4 to form solution V1; potassium aluminum cyanide and water are mixed in a mass ratio of 1:5 to form solution V2. Prepare an aqueous solution M with a magnesium content of 4 wt.% and a calcium content of 6 wt.%.

[0026] R1 and V1 are mixed at a mass ratio of 1:1 and reacted thoroughly in a sufficient amount of M for at least 10 hours, with a stirring rate of 200 rpm and a temperature of 15°C. After solid-liquid separation, the solid product is adsorbent X1 Na [Al2(CN2)2], which is the adsorbent used in Example 2. The liquid can be recycled for the preparation of adsorbents.

[0027] R2 and V2 are mixed at a mass ratio of 2:1 and reacted thoroughly in a sufficient amount of M for at least 10 hours, with a stirring rate of 300 rpm and a temperature of 30°C. After solid-liquid separation, the solid product is the adsorbent Na3[Al2(CN2)3], which is the adsorbent used in Example 3. The liquid can be recycled for the preparation of adsorbents.

[0028] R3 and V2 are mixed at a mass ratio of 1:1 and reacted thoroughly in a sufficient amount of M for at least 10 hours, with a stirring rate of 240 rpm and a temperature of 20°C. After solid-liquid separation, the solid product is the adsorbent Na4[Al2(CN2)4], which is the adsorbent used in Example 4. The liquid can be recycled for the preparation of adsorbents.

[0029] R4 and V1 are mixed at a mass ratio of 2:1 and reacted thoroughly in a sufficient amount of M for at least 10 hours, with a stirring rate of 200 rpm and a temperature of 15°C. After solid-liquid separation, the solid product is the adsorbent Na4[Ca2(CN2)4]. The liquid can be recycled for the preparation of other adsorbents. Example 2

[0030] A certain amount of raw brine (L1) from the salt lake, 50.0 kg, was taken. Its chemical composition is as follows: (1) Brine composition: K + -0.19 wt.%; Mg 2+ -0.08wt.%; Cl - -1.30wt.%; SO4 2- -1.90wt.%; CO3 2- -0.25 wt.%; Rb + -0.0006 wt.%; Cs + -0.0008wt.%.

[0031] (2) The brine was placed in an evaporation tank and evaporated at room temperature using an exhaust fan. The concentration of rubidium and cesium in the brine was periodically checked and sampled for analysis. Evaporation was stopped when the concentration reached 300 mg / L. The weight of the rubidium- and cesium-enriched brine L2 was 8.25 kg. The chemical composition of L2 was: K + -4.50 wt.%; Mg 2+ -0.93 wt.%; Cl - -18.00wt.%; SO4 2- -5.82 wt.%; CO3 2- -1.20wt.%; Rb + -0.0036 wt.%; Cs + -0.0048 wt.%.

[0032] (3) Add 295 mL of adsorbent X1 (Na [Al2(CN2)2]) to the L2 brine above and stir it at a stirring speed of 200 rpm for 5 h.

[0033] (4) Solid-liquid separation (3) After the system is completed, the adsorbed tail liquid L3 is returned and mixed with L1. 295 mL of 0.2 M hydrochloric acid solution is added to the adsorbent X2-Rb(Cs)2[Al2(CN2)2] which has adsorbed rubidium and cesium, and the mixture is stirred at a speed of 200 rpm for 2 h. Solid-liquid separation yields the first high rubidium and cesium content solution L4 and the desorbed adsorbent.

[0034] The chemical composition of the adsorption tail liquid L3 is as follows: K + -4.50 wt.%; Mg 2+ -0.93 wt.%; Cl - -18.00wt.%; SO4 2- -5.82 wt.%; CO3 2- -1.20wt.%; Rb + -0.0009wt.%; Cs + -0.0009wt.%.

[0035] The chemical composition of the first high rubidium and cesium content solution L4 is as follows: K + -0.004wt.%; Mg 2+ -0.002wt.%; Cl - -11.68wt.%; SO4 2- -0.001wt.%; CO3 2- -0.001wt.%; Rb + -0.461 wt.%; Cs + -0.611wt.%.

[0036] (5) Add 236 mL of 20.0 wt% sodium chloride solution to the adsorbent desorbed in (4), stir at 200 rpm for 0.5 h. After solid-liquid separation, regenerated liquid L5 is obtained. L5 is mixed with L4 to obtain a second high rubidium and cesium content solution as a raw material for further extraction of rubidium and cesium. The regenerated adsorbent X4 is returned to (3) for recycling.

[0037] The chemical composition of regenerated solution L5 is as follows: K + -0.002wt.%; Mg 2+ -0.002wt.%; Cl - -3.21wt.%; SO4 2- -0.001wt.%; CO3 2- -0.002wt.%; Rb + -0.0031 wt.%; Cs + -0.0021wt.%.

[0038] (6) The rubidium adsorption rate of this method is 83.3%, the desorption rate is 81.5%, and the total yield is 82.1%; the cesium adsorption rate is 85.4%, the desorption rate is 81.0%, and the total yield is 80.9%. Example 3

[0039] A certain amount of raw brine (L1) from a salt lake, 50.0 kg, was taken. Its chemical composition is as follows: (1) Brine composition: K + -0.25 wt.%; Mg 2+ -0.04wt.%; Cl - -1.20wt.%; SO4 2- -2.10wt.%; CO3 2- -0.28 wt.%; Rb + -0.0008 wt.%; Cs + -0.0010wt.%.

[0040] (2) The brine was placed in an evaporation tank and evaporated at room temperature using an exhaust fan. The concentration of rubidium and cesium in the brine was periodically checked and sampled for analysis. Evaporation was stopped when the concentration reached 300 mg / L. The weight of the rubidium- and cesium-enriched brine L2 was 13.00 kg. The chemical composition of L2 was: K + -4.00 wt.%; Mg 2+ -0.80wt.%; Cl - -17.00wt.%; SO4 2- -6.10 wt.%; CO3 2- -1.30 wt.%; Rb + -0.0030wt.%; Cs + -0.0037 wt.%.

[0041] (3) Add 390.0 ml of adsorbent X1 (Na3[Al2(CN2)3]) to the L2 brine above and stir it at a stirring speed of 170 rpm for 8 h.

[0042] (4) Solid-liquid separation (3) After the system is completed, the adsorbed tail liquid L3 is returned and mixed with L1. 195 mL of 0.5 M hydrochloric acid solution is added to the adsorbent X2-Rb(Cs)4[Al2(CN2)3] that has adsorbed rubidium and cesium, and the mixture is stirred at a stirring rate of 180 rpm for 3 h. Solid-liquid separation yields the first high rubidium and cesium content solution L4 and the desorbed adsorbent.

[0043] The chemical composition of the adsorption tail liquid L3 is as follows: K + -4.00 wt.%; Mg 2+-0.80 wt.%; Cl - -17.00wt.%; SO4 2- -6.10 wt.%; CO3 2- -1.30wt.%; Rb + -0.0001wt.%; Cs + -0.0002wt.%.

[0044] The chemical composition of the first high rubidium and cesium content solution L4 is as follows: K + -0.004wt.%; Mg 2+ -0.002wt.%; Cl - -11.03wt.%; SO4 2- -0.001wt.%; CO3 2- -0.001wt.%; Rb + -0.124 wt.%; Cs + -0.155wt.%.

[0045] (5) Add 390.0 mL of 20 wt% sodium chloride solution to the adsorbent desorbed in (4), stir at 170 rpm for 0.7 h. After separation, regenerated liquid L5 is obtained. L5 is mixed with L4 to obtain a second high rubidium and cesium content solution as a raw material for further extraction of rubidium and cesium. The regenerated adsorbent X4 is returned to (3) for recycling.

[0046] The chemical composition of regenerated solution L5 is as follows: K + -0.001wt.%; Mg 2+ -0.002wt.%; Cl - -2.91wt.%; SO4 2- -0.002wt.%; CO3 2- -0.001wt.%; Rb + -0.0021 wt.%; Cs + -0.0017wt.%.

[0047] (6) The rubidium adsorption rate of this method is 96.7%, the desorption rate is 92.2%, and the total yield is 91.4%; the cesium adsorption rate is 95.9%, the desorption rate is 93.5%, and the total yield is 91.3%. Example 4

[0048] A certain amount of raw brine (L1) from a salt lake, 50.0 kg, was taken. Its chemical composition is as follows: (1) Brine composition: K + -0.20 wt.%; Mg 2+ -0.05wt.%; Cl- -1.27wt.%; SO4 2- -2.00wt.%; CO3 2- -0.28 wt.%; Rb + -0.0007 wt.%; Cs + -0.0009wt.%.

[0049] (2) The brine was placed in an evaporation tank and evaporated at room temperature using an exhaust fan. The concentration of rubidium and cesium in the brine was periodically checked and sampled for analysis. Evaporation was stopped when the concentration reached 300 mg / L. The weight of the rubidium- and cesium-enriched brine L2 was 10.00 kg. The chemical composition of L2 was: K + -4.35 wt.%; Mg 2+ -0.90 wt.%; Cl - -17.55wt.%; SO4 2- -6.00wt.%; CO3 2- -1.30 wt.%; Rb + -0.0034 wt.%; Cs + -0.0043wt.%.

[0050] (3) Add 343 mL of adsorbent X1 (Na4[Al2(CN2)4]) to the L2 brine above and stir it at a stirring speed of 160 rpm for 7 h.

[0051] (4) Solid-liquid separation (3) After the system is completed, the adsorbed tail liquid L3 is returned and mixed with L1. 229 mL of 0.3 M hydrochloric acid solution is added to the adsorbent X2-Rb(Cs)3[Al2(CN2)4] which has adsorbed rubidium and cesium, and the mixture is stirred at a stirring rate of 170 rpm for 3 h. The solid-liquid separation yields the first high rubidium and cesium content solution L4 and the desorbed adsorbent.

[0052] The chemical composition of the adsorption tail liquid L3 is as follows: K + -4.35wt.%; Mg 2+ -0.90 wt.%; Cl - -17.55wt.%; SO4 2- -6.00 wt.%; CO3 2- -1.30wt.%; Rb + -0.0002wt.%; Cs + -0.0002wt.%.

[0053] The chemical composition of the first high rubidium and cesium content solution L4 is as follows: K + -0.002wt.%; Mg2+ -0.001wt.%; Cl - -11.39wt.%; SO4 2- -0.002wt.%; CO3 2- -0.002wt.%; Rb + -0.371wt.%; Cs + -0.494wt.%.

[0054] (5) Add 343 mL of 10 wt% sodium chloride solution to the desorbed adsorbent in (4), stir at 190 rpm for 1.0 h. After solid-liquid separation, regenerated liquid L5 is obtained. L5 is mixed with L4 to obtain a second high rubidium and cesium content solution as a raw material for further extraction of rubidium and cesium. The regenerated adsorbent X4 is returned to (3) for recycling.

[0055] The chemical composition of regenerated solution L5 is as follows: K + -0.002wt.%; Mg 2+ -0.001wt.%; Cl - -3.00wt.%; SO4 2- -0.002wt.%; CO3 2- -0.001wt.%; Rb + -0.0021 wt.%; Cs + -0.0021wt.%.

[0056] (6) The rubidium adsorption rate of this method is 94.1%, the desorption rate is 90.1%, and the total yield is 89.7%; the cesium adsorption rate is 95.4%, the desorption rate is 93.1%, and the total yield is 92.5%.

[0057] The applicant declares that the detailed method of the present invention is illustrated by the above embodiments, but the present invention is not limited to the above detailed method, that is, it does not mean that the present invention must rely on the above detailed method to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A compound having the structural formula shown in Formula I: A n [B2(CN2) m ] (I), Where A is one or two of Na, K, Mg, and Ca. B is either Al or Fe. n is 1, 2 or 3, m is 2 or 4; CN2 is a cyano group.

2. The compound according to claim 1, characterized in that, The A is one of Na, K, Mg, and Ca.

3. An application of the compound according to claim 1 or 2 as an adsorbent.

4. A method for simultaneous separation of rubidium and cesium in weakly carbonated salt lake brine, characterized in that, Includes the following steps: S1. Take a certain amount of brine and evaporate it at room temperature until the concentrations of rubidium and cesium are both greater than 300 mg / L, then stop evaporation to obtain brine enriched with rubidium and cesium. K in the brine + The content is 0.19~0.25 wt.%, Mg 2+ Content is 0.04~0.08 wt.%; Cl - The content is 1.20~1.30 wt.%; SO4 2- Content was 1.90~2.10 wt.%; CO3 2- The content is 0.25~0.28 wt.%; Rb + Content is 0.00060~0.00080 wt.%; Cs + The content is 0.0008~0.0010 wt.%; K in brine enriched with rubidium and cesium + The content is 4.00~4.50 wt.%; Mg 2+ The content is 0.80~0.93 wt.%; Cl - The content is 17.00~18.00 wt.%; SO4 2- Content was 5.82~6.10 wt.%; CO3 2- Content was 1.20~1.30 wt.%; Rb + The content is 0.0300~0.0389 wt.%; Cs + The content is 0.0300~0.0535 wt.%; S2, the rubidium- and cesium-enriched brine is mixed with an adsorbent to obtain a first mixture for adsorption process, wherein the volume ratio of the rubidium- and cesium-enriched brine to the adsorbent in the first mixture is 28:1 to 40:

1. The adsorbent is the compound according to claim 1 or 2; The structural formula of the compound is shown in Formula I: A n [B2(CN2) m ] (I), Where A is one or two of Na, K, Mg, and Ca. B is either Al or Fe. n is 1, 2 or 3, m is 2 or 4; CN2 is a cyano group; Optionally, A is one of Na, K, Mg, and Ca; Optionally, the first mixture is stirred during the adsorption process; S3, the first mixture that has completed the adsorption process is subjected to solid-liquid separation to obtain the liquid phase as the adsorption tail liquid and the solid phase as the adsorbent that has adsorbed rubidium and cesium. S4, the adsorbent that has adsorbed rubidium and cesium is mixed with dilute hydrochloric acid to obtain a second mixture for desorption process, wherein the volume ratio of the adsorbent that has adsorbed rubidium and cesium to the dilute hydrochloric acid in the second mixture is 1:1 to 2:1; and the concentration of the dilute hydrochloric acid is 0.2 to 0.5 M. Optionally, the second mixture is stirred during the desorption process; S5, the second mixture that has completed the desorption process is subjected to solid-liquid separation to obtain a liquid phase which is a first high rubidium and cesium content solution, and a solid phase which is the desorbed adsorbent.

5. The method for simultaneous separation of rubidium and cesium in weakly carbonated salt lake brine according to claim 4, characterized in that, In S2, the stirring speed is no more than 200 rpm and the stirring time is no less than 5 hours.

6. The method for simultaneous separation of rubidium and cesium in weakly carbonated salt lake brine according to claim 4, characterized in that, In S3, the stirring speed is no more than 200 rpm and the stirring time is no less than 2 hours.

7. The method for simultaneous separation of rubidium and cesium in weakly carbonated brine according to claim 4, characterized in that, The adsorption tail liquid is returned to step 1 as a brine raw material for reuse.

8. The method for simultaneous separation of rubidium and cesium in weakly carbonated salt lake brine according to claim 4, characterized in that, The process also includes step S6, where the desorbed adsorbent is mixed with a sodium chloride solution to obtain a third mixture for regeneration. The volume ratio of the desorbed adsorbent to the sodium chloride solution in the third mixture is 1:0.8~1; the concentration of the sodium chloride solution is 5.0wt%~20.0wt%. Optionally, the third mixture is stirred during the regeneration process; The third mixture after the regeneration process is subjected to solid-liquid separation. The liquid phase is the regenerated liquid, which is mixed with the first high rubidium and cesium content solution in S5 to obtain the second high rubidium and cesium content solution. The resulting solid phase is the regenerated adsorbent, which is returned to step S2 for reuse.

9. The method for simultaneous separation of rubidium and cesium in weakly carbonated salt lake brine according to claim 4, characterized in that, In S6, the stirring speed is no more than 200 rpm and the stirring time is no less than 0.5 h.

10. The method for simultaneous separation of rubidium and cesium in weakly carbonated brine according to claim 4, characterized in that, K in the adsorption tail liquid + The content is 4.00~4.50 wt.%; Mg 2+ The content is 0.80~0.93 wt.%; Cl - The content is 17.00~18.00 wt.%; SO4 2- Content was 5.82~6.10 wt.%; CO3 2- Content was 1.20~1.30 wt.%; Rb + The content is 0.0010~0.0019 wt.%; Cs + The content is 0.0015~0.0018 wt.%; K in the first high rubidium cesium content solution + The content is 0.002~0.004 wt.%; Mg 2+ The content is 0.001~0.002 wt.%; Cl - The content is 11.03~11.68 wt.%; SO4 2- Content is 0.001~0.002 wt.%; CO3 2- Content is 0.001~0.002 wt.%; Rb + The content is 0.0244~0.0541 wt.%; Cs + The content is 0.0320~0.0730 wt.%. K in the regenerated liquid + The content is 0.001~0.002 wt.%; Mg 2+ The content is 0.001~0.002 wt.%; Cl - The content is 2.91~3.21 wt.%; SO4 2- Content is 0.001~0.002 wt.%; CO3 2- Content is 0.001~0.002 wt.%; Rb + The content is 0.00321~0.0031 wt.%; Cs + The content is 0.0017~0.0027 wt.%.