CN108479719B

CN108479719B - High-performance ion exchange type adsorbent, preparation and application for extracting rubidium/lithium

Info

Publication number: CN108479719B
Application number: CN201810368184.5A
Authority: CN
Inventors: 王磊; 孟晓荣; 黄丹曦; 李陈; 霍姗姗; 乔茹楷; 吴浩; 陈铖
Original assignee: Shaanxi Membrane Separation Technology Research Institute Co ltd
Current assignee: Xi'an jinzang membrane Environmental Protection Technology Co.,Ltd.
Priority date: 2018-04-23
Filing date: 2018-04-23
Publication date: 2021-05-07
Anticipated expiration: 2038-04-23
Also published as: CN108479719A

Abstract

The invention discloses a high-performance ion exchange adsorbent, preparation and application for extracting rubidium/lithium. The adsorbent forming material provided by the invention is a hydrophilic polymer, is beneficial to the lithium/rubidium ion exchange type adsorbent to carry out quick and effective ion exchange, is simple, convenient and quick in chemical crosslinking method, can be repeatedly operated in time when the adsorbent is subjected to dissolution loss in the production of adsorbing and extracting lithium/rubidium, and does not influence the production. The preparation process is simple, the operation is convenient, and the condition is mild. The adsorption and desorption speed of the adsorbent is high, and the production cost of adsorbing and extracting lithium/rubidium is greatly reduced.

Description

High-performance ion exchange type adsorbent, preparation and application for extracting rubidium/lithium

Technical Field

The invention belongs to the technical field of adsorbent preparation, and particularly relates to a high-performance ion exchange adsorbent, preparation and application in rubidium/lithium extraction.

Background

Lithium metal and compounds thereof play more and more important roles in national economy and national defense construction, and more than 80% of lithium resources are stored in salt lake brine and seawater, so that research on extracting lithium from the salt lake brine has great strategic significance on development and utilization of the lithium resources. The method for extracting lithium by the ion sieve adsorption method has the characteristics of high cycle stability, high selectivity, high adsorption quantity, low cost and the like, and becomes one of the most promising methods for extracting lithium from salt lake brine in China. However, most of the ion sieve adsorbent is powder, and the fluidity and permeability of the ion sieve adsorbent are poor, so that the direct application of the ion sieve adsorbent to a fixed bed for adsorbing and extracting lithium has certain difficulty, and therefore, the forming of the ion sieve powder is the key for realizing the industrialization of extracting lithium by using the ion sieve.

The forming agent in the existing forming ion sieve adsorbent is rich in PVC, PVDF or other hydrophobic polymers, so that the ion sieve cannot be effectively contacted and exchanged with water, the adsorption rate and the adsorption quantity of the adsorbent are reduced, and the embedded powder is easy to fall off. The existing hydrophilic polymer such as sodium alginate embedded adsorbent has strong hydrophilicity, but the prepared product can not be used in the solution environment containing carbonate or sulfate radical which can generate chemical action with calcium ions due to the adoption of calcium ion complexing and precipitation method forming technology, so that the application range of the adsorbent is limited, the mechanical strength is not high, and the problem of unstable structure and performance caused by dissolution loss in the using process still exists. Therefore, how to maintain the performance of the powder ionic sieve in the forming process becomes a key problem for industrialization of lithium extraction placed in the ionic sieve.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the invention aims to provide a high-performance ion exchange adsorbent, preparation and application of extracting rubidium/lithium, and solves the problem that the adsorbent prepared from a hydrophilic material is easy to be unstable due to material dissolution in repeated use.

In order to achieve the purpose, the invention adopts the following technical scheme:

a process for preparing high-performance ion-exchange adsorbent includes such steps as embedding lithium ion adsorbent or rubidium ion adsorbent in hydrophilic polymer, extruding out, and chemically cross-linking.

Optionally, the lithium ion adsorbent is Li_xMn_3-xO₄The manganese oxide lithium ion sieve of (1), wherein x is 1.6, 1.33 or 1;

the rubidium ion adsorbent is ammonium phosphomolybdate or ammonium tungstomolybdate.

Optionally, the hydrophilic polymer is at least one of hydroxyethyl cellulose, sodium carboxymethyl cellulose or water-soluble starch;

the embedding is to extrude a sticky substance which is uniformly mixed with a lithium ion adsorbent or rubidium ion adsorbent with the mass ratio of 1-1.5/1 to hydrophilic polymer and a hydrophilic polymer aqueous solution with the mass ratio of 30% -50% into spherical particles with the particle size of 1-3 mm, and then air-dry and solidify the spherical particles to obtain the spherical adsorbent.

Optionally, the chemical crosslinking is to pack the spherical adsorbent obtained by air drying and curing into an adsorption column, and the packing density is 0.7-0.9 kg.m based on 50% of water content of the spherical adsorbent^-3；

Pumping 1mol/L hydrochloric acid aqueous solution of 3-5% of dialdehyde at the temperature of 30 ℃ into a spherical adsorbent penetrating through an adsorption column at the flow rate of 10L/h from the bottom of the adsorption column, keeping the temperature at the temperature of 30 ℃ for 30min, ejecting residual liquid from the top of the adsorption column at the positive pressure of 1MPa, and changing the penetrating direction of the 1mol/L hydrochloric acid aqueous solution of the dialdehyde at the temperature of 3-5% to repeat the operation once.

Optionally, the dialdehydes are selected from glyoxal, glutaraldehyde, succinaldehyde, and heptadialdehyde.

The high-performance ion exchange adsorbent is prepared by adopting the preparation method of the high-performance ion exchange adsorbent.

The high-performance ion exchange adsorbent prepared by the preparation method of the high-performance ion exchange adsorbent is applied to adsorbing and extracting rubidium ions or lithium ions in water.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention provides a method for preparing lithium and rubidium ion sieve powder, which uses an embedding method of hydrophilic polymer, and can generate good hydrogen bond action with water, so that the water and the interior of an adsorbent can be well exchanged, and therefore, the adsorption rate is high, and the resolution rate is high. The problem that the adsorption performance of the adsorbent is affected because the ionic sieve cannot be effectively contacted and exchanged with water due to the strong hydrophobicity of the material of the ionic sieve coated by polymers such as PVC or PVDF is effectively solved. Is a high-efficiency adsorbent production method.

(2) The adsorbent preparation technology of the invention adopts the phase inversion method of heating and volatilizing the aqueous solution of the high molecular material for embedding, and avoids the production wastewater in the phase inversion method process of the organic solvent, instead of the solution phase inversion method of the existing adsorbent preparation technology.

(3) The chemical crosslinking reaction of the present invention employs an acetalization reaction between an aldehyde and a hydroxyl group in a hydrophilic polymer. Because the reaction system is carried out in a water phase and the reaction rate is high, the method is carried out in a mode of direct crosslinking reaction in the adsorption column, the method can be carried out in the production process, when the adsorbent has partial dissolution loss action in the use process, the adsorption is not required to be replaced, and the online crosslinking method can be directly and timely adopted to prevent the adsorbent from losing efficacy. Effectively saving the production cost.

(4) The adsorbent prepared by the method has strong applicability, and can be widely applied to extracting lithium or rubidium ions from seawater, brine, lepidolite acid-leaching lithium raffinate and lithium carbonate precipitation lithium raffinate.

(5) The preparation method has the advantages of simple preparation process, convenient operation and mild conditions; high production efficiency and low cost. CN103316623A "a method for preparing spherical lithium ion sieve adsorbent", comprising: heating, dissolving and mixing the polysaccharide and the solvent, adding the ionic sieve precursor into the solution, and uniformly stirring to obtain a viscous solution; dripping the viscous solution into an oil phase at 50-100 ℃ to obtain a solid spherical adsorbent with the particle size of 2-5 mm; placing the spherical adsorbent in a cross-linking agent, cross-linking for 10-30 h at 20-80 ℃, filtering and washing to obtain cross-linked spherical MnO2 adsorbent particles; and eluting the adsorbent particles in a lithium removal solvent to finally prepare the spherical lithium ion sieve adsorbent. Therefore, the polysaccharide is selected in the preparation method, the reaction process is long in time (crosslinking is 10-30 hours), and the oil phase is dripped into the reaction product at a high reaction temperature of 50-100 ℃. From the whole process, the method provided by the patent technology has long production period, uses a large amount of reagents and conditions which are expensive, scarce and environmentally-friendly. Meanwhile, once the adsorbent is dissolved and damaged in a large area in the using process, the adsorbent cannot be repaired conveniently and timely, and only can be replaced and updated, so that great inconvenience and waste are brought to production.

"CN 102631897A a method for preparing lithium adsorbent resin", firstly, preparing a precursor of the lithium adsorbent resin; uniformly mixing the prepared precursor with an adhesive and a pore-forming agent to prepare a dispersed phase; preparing a continuous phase incompatible with the dispersed phase; adding the dispersed phase into the continuous phase, stirring to disperse the dispersed phase into balls with proper granularity, and solidifying the balls into spherical particles under certain conditions; and fifthly, removing substances such as a dispersing agent, a pore-forming agent and the like in the spherical particles by using a solvent, and performing activation treatment to obtain the lithium adsorbent resin capable of extracting lithium from the high-magnesium low-lithium brine. The polyvinyl alcohol acts as a dispersant in the paper, and the adsorbent which is not easy to disperse, has high performance and can be repeatedly used is prepared by combining the preparation method and the selection of the cross-linking agent.

Based on the reasons, the invention prepares the high-hydrophilicity polymer material according to the ion exchange mechanism in the extraction process of lithium or rubidium ions from seawater, brine, mica mineral acid lithium extraction raffinate, lithium carbonate precipitation lithium extraction raffinate and the like, by screening raw materials and controlling the factors such as reagents, dosage, preparation parameters and the like in the production process, so as to be beneficial to the forming technology of the adsorbent for ion exchange, and adopts simple and mild chemical crosslinking technology and method.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a graph of the morphology of the adsorbents prepared in example 1, (a)500 times, (b)1000 times;

FIG. 2 is a graph of the morphology of the adsorbents prepared in example 2, (a)500 times, (b)1000 times;

the invention is described in detail below with reference to the drawings and the detailed description.

Detailed Description

The invention discloses a preparation method of a high-performance ion exchange adsorbent, which comprises the following steps: (1) preparing a 30-50% aqueous solution of a hydrophilic polymer, adding a powdery lithium or rubidium ion adsorbent into the aqueous solution of the hydrophilic polymer, heating and evaporating to remove part of water, extruding into a spherical shape, and drying and molding in hot air; (2) loading the spherical adsorbent into an adsorption column, wherein the loading density of the spherical adsorbent is 0.7-0.9 kg.m based on 50% water content^-3(ii) a 2/3, pumping 3-5% 1M hydrochloric acid aqueous solution of dialdehyde from the bottom of the column into the column at a flow rate of 10L/h, immersing the adsorption balls, reacting at 30 deg.C for 30min, and ejecting residual liquid from the top of the column under a pressure of 1 atm; (3) repeating the process (2) but with the dialdehyde crosslinker solution entering from the top of the column and exiting from the bottom of the column; (4) the adsorption ball in the column was washed at a flow rate of 10mL/min until the effluent was neutral.

The high-performance ion exchange adsorbent prepared by the invention is mainly used for adsorbing and extracting rubidium ions or lithium ions from seawater, brine, lepidolite acid-leaching lithium raffinate, lithium carbonate precipitation lithium-leaching raffinate and the like.

The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention. The percentage concentrations are mass percentage concentrations unless otherwise specified.

Example 1:

(1) taking 10g of manganese series lithium ion sieve adsorbent Li₄Mn₅O₄And adding the mixture into 30g of 30% hydroxyethyl cellulose solution, and uniformly mixing to obtain a viscous solid-liquid mixture.

(2) Wrapping the viscous solid-liquid mixture with an aluminum plate, manually extruding the mixture into a spherical shape, blowing the moisture on the surface of the spherical shape by hot air, and curing the spherical shape.

(3) Loading the surface-solidified spherical adsorbent into an adsorption column with diameter of 1cm and height of 25cmA loading density of 0.7 to 0.9kg m in terms of 50% water content^-3And the bottom end is closed, negative pressure of 0.01MPa is added from the upper end, the bottom of the column port is inserted into 1M hydrochloric acid aqueous solution of 3 percent glutaraldehyde, the negative pressure is stopped after the adsorption column is quickly filled with the glutaraldehyde aqueous solution, and the reaction is carried out for 30min at the temperature of 30 ℃. The residue was pressed out from the top with a positive pressure of 1 MPa. The above operation was repeated, and the crosslinking agent liquid was sucked from the upper part, and the residual liquid was ejected from the bottom. The flow speed of the 1M hydrochloric acid aqueous solution liquid of 3 percent glutaraldehyde in the adsorption column is 10L/h;

(4) after the reaction was completed, the adsorbent in the column was washed with water at a flow rate of 10mL/min until the eluate was neutral.

The SEM of the adsorbent obtained in example 1 is shown in FIG. 1, wherein a is a 500-fold enlarged view and b is a 1000-fold enlarged view in FIG. 1;

the adsorbent obtained above is injected with brine containing lithium ion 200mg/L at a flow rate of 2.5mL/min, and the adsorption is balanced after 4 h. The solution was analyzed at a flow rate of 1mL/L using a 0.5moL/L hydrochloric acid solution, and the solution was equilibrated after 4 hours. The amount of the adsorbent adsorbed lithium ions was found to be 12.2mg/g, and the resolution was found to be 92%.

Example 2:

example 2 is different from example 1 in that the manganese-based lithium ion sieve used is LiMn₂O₄The operation process, the raw material dosage, the reaction conditions, the brine and the like are the same, the adsorption quantity of the adsorbent to lithium in the brine under the same conditions is 8mg/g, and the resolution rate reaches 95%.

Example 3:

the difference between example 3 and example 1 is that the rubidium ion adsorbing material is ammonium phosphomolybdate, and the dosage of the rubidium ion adsorbing material is 5 g. Rubidium ion adsorbent powder and 10g of 50% hydroxyethyl cellulose solution are blended into a viscous liquid-solid mixture, and other operation processes, raw materials and dosage are the same as those in example 1.

The SEM image of the rubidium ion adsorbent obtained in example 3 is shown in FIG. 2, wherein the image a is a 500-fold enlarged image, and the image b is a 1000-fold enlarged image;

and eluting the obtained adsorbent with 20% ammonium chloride solution at 40 ℃ for 48h at the flow rate of 1mL/L until rubidium ions in the eluent cannot be detected. And (3) leaching the lithium mother liquor by lepidolite sulfuric acid containing 80mg/L rubidium ions, injecting the sample at the flow rate of 1.5mL/min, and after 24 hours, balancing the adsorption. The solution was analyzed with a 20% ammonium chloride solution at a flow rate of 1mL/L, and the solution was equilibrated after 24 hours. The adsorption amount of the adsorbent to rubidium ions was measured to be 42.2mg/g, and the resolution in a 20% ammonium chloride solution was measured to be 95%.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. A preparation method of a high-performance ion exchange adsorbent is characterized in that a lithium ion adsorbent or a rubidium ion adsorbent is embedded in a hydrophilic polymer, extruded and formed, and obtained through chemical crosslinking;

the lithium ion adsorbent is a manganese oxide lithium ion sieve of LixMn3-xO4, wherein x is 1.6, 1.33 or 1;

the rubidium ion adsorbent is ammonium phosphomolybdate or ammonium tungstomolybdate;

the hydrophilic polymer is at least one of hydroxyethyl cellulose, sodium carboxymethyl cellulose or water-soluble starch;

the embedding is to extrude a sticky substance which is uniformly mixed with a lithium ion adsorbent or rubidium ion adsorbent with the mass ratio of 1-1.5/1 to hydrophilic polymer and a hydrophilic polymer aqueous solution with the mass ratio of 30% -50% into spherical particles with the particle size of 1-3 mm, and then air-drying and curing the spherical particles to obtain the spherical adsorbent;

the chemical crosslinking is to pack the spherical adsorbent obtained by air drying and curing into an adsorption column, and the packing density is 0.7-0.9 kg.m based on 50% of the water content of the spherical adsorbent^-3；

2. The method for preparing a high performance ion exchange adsorbent according to claim 1, wherein the dialdehyde is selected from glyoxal, glutaraldehyde, succinaldehyde, and heptadialdehyde.

3. A high-performance ion exchange adsorbent, which is prepared by the method for preparing a high-performance ion exchange adsorbent according to any one of claims 1 to 2.

4. Use of the high performance ion exchange adsorbent prepared by the method of any one of claims 1-2 to adsorb and extract rubidium or lithium ions from water.