CN1491891A

CN1491891A - New process for synthesizing lithium ion separation material

Info

Publication number: CN1491891A
Application number: CNA031358071A
Authority: CN
Inventors: 辉钟; 钟辉; 许惠
Original assignee: Chengdu Univeristy of Technology
Current assignee: Chengdu Univeristy of Technology
Priority date: 2003-09-12
Filing date: 2003-09-12
Publication date: 2004-04-28
Anticipated expiration: 2023-09-12
Also published as: CN1247306C

Abstract

TiO2 or H2TiO3 and Li2CO3, LiOH or LiNO3 as initial materials are processed in sol-like soaking process via mixing with C13 below organic solvent and/or water for the reactants to diffuse mutually to form molecule level mixture in sol state, and the mixture is evaporated and dried to obtain the precursor for lithium ion separating material. The precursor is incinerated at high temperature to synthesize lithium-type lithium ion permutoid, which is then washed with HCl to elute Li ion and converted into hydrogen-type lithium ion permutoid. The permutoid may be used to adsorb lithium ion in low content in bittern, and the adsorbed permutoid may be HCl eluted and regenerated into hydrogen-type lithium ion permutoid for reuse. The permutoid has higher memory selectivity and exchange capacity to lithium ion in bittern and low dissolving loss rate, and thus may be used as separating material for extracting lithium ion from bittern directly.

Description

Novel method for synthesizing lithium ion separation material

The invention relates to a synthesis method of a separation material for separating and extracting lithium from brine.

Lithium and lithium compounds are used as energy materials urgently needed by high technology and widely applied to industries such as energy, chemical industry, metallurgy, ceramics and the like, the global demand for the lithium and the lithium compounds is increasing day by day, and the demand for lithium products in the world is increased at a speed of 5-8% per year according to statistics. Therefore, the separation and extraction of lithium is one of the major industries that are currently developed in priority in various countries in the world. The salt lake brine and the underground brine contain a large amount of lithium, and are the most main and economic lithium resource for producing lithium compounds at present.

The method for separating and extracting lithium from brine mainly adopts a salt field method, an extraction method and the like at present, wherein the salt field method is to naturally evaporate brine through salt field brine drying, separate out sodium chloride, potassium magnesium mixed salt and Li⁺Remaining in the old brine solution, removing boron by a precipitation method, and removing SO by the precipitation method₄ ^2～Natural evaporation of MgCl₂·6H₂O, etc. separation step of Li⁺In a dissolved state and a large amount of Na in brine⁺、Li⁺、K⁺、Mg²⁺、B₂O₃、SO₄ ^2～Etc. further separated when Li is present⁺Adding Na when the concentration reaches 15-25 g/L₂CO₃Precipitation reaction to form Li₂CO₃Product, process applicable to Li⁺High content (generally more than or equal to 1000Mg/L) of Mg²⁺The salt lake brine with low content and good natural evaporation condition is not suitable for Li⁺Low-content brine; the extraction method comprises evaporating brine, concentrating, extracting with organic extractant (such as TBP) to obtain Li⁺Into the organic phase with Mg²⁺、Ca⁺、Na⁺、K⁺Isoseparating, back extracting with water, and separating Li⁺Existing in water phase, evaporating, and concentrating to obtain Li⁺The content of the Na is 15-25 g/L, and then Na is added₂CO₃Precipitation reaction to obtain Li₂CO₃. This method is not suitable for Li⁺Low brine (e.g. Li)⁺Less than 200mg/L), and has large investment and high separation cost.

The method for extracting lithium by directly using the brine with low lithium content has the characteristics of low cost, no environmental pollution and low investment, and is the development direction of lithium production and research at home and abroad at present. Due to Li in brine⁺The content is generally low (generally dozens to hundreds of mg/L), and the content is coexisted with a large amount of alkali metal and alkaline earth metal ions with similar properties, so that the separation and extraction are very difficult. It has been studied to extract and separate Li from brine with low lithium content by using chelating resin⁺Although for the resin Li⁺Has better selective adsorption property, butHigh cost, Li⁺Is not easy to be released, can not be used in industry, and can only be used as Li in chemical analysis⁺A separation and enrichment method.

In view of the above circumstances, it is an object of the present invention to provide a novel method for synthesizing an inorganic lithium ion separation material by starting with TiO₂Or H₂TiO₃With lithium compounds (e.g. LiNO)₃、Li₂CO₃LiOH, etc.) and calcining at 500-1000 deg.C to obtain TiO₂Is subjected to solid phase reaction with a lithium compound to produceRemoving H from lithium metatitanate type composite oxide with O-Ti-O as skeleton by acid washing⁺With Li⁺Ion exchange reaction takes place, Li⁺Is removed and converted into a hydrogen-type composite oxide having a structure capable of accommodating only Li⁺For Li⁺Shows special memory and selectivity, thereby realizing the extraction of Li from a solution containing a large amount of alkali metal and alkaline earth metal ions⁺。

The invention also provides a method for synthesizing the composite oxide between a solid phase method and a liquid phase method, namely a Like Sol-Impregnation method (Like-Sol-Impregnation), which uses TiO₂Or H₂TiO₃Starting from LiOH H₂O、Li₂CO₃Or LiNO₃Adding lithium source in the molar ratio of Li to Ti of 1.05-1.15 to 2.0, adding mixed solution of organic solvent with less than 13 carbon atoms and water in the weight ratio of 1 to 0-0.8 into the initiator, stirring and soaking to diffuse the reactants into each other to form sol, evaporating or spray drying to form precursor, calcining at 500-1000 deg.c for 10-40 hr to obtain lithium type exchanger, eluting with HCl in 0.1-0.5 mol/L to convert into hydrogen type lithium ion exchanger, and adsorbing Li in granular bittern⁺Or loading into ion exchange column for extracting lithium from column type bittern.

Mixing the mixed solution of the organic solvent and water with TiO₂Or H₂TiO₃And LiOH. H₂O、Li₂CO₃Or LiNO₃Mixing and dipping, wherein the dipping time is generally 30-180 minutes, and the mixing ratio of the dipping time and the starting materials is 1: 1.0-3.0 (weight ratio).

The impregnated and dried precursor is preferably calcined at 500-1000 deg.C, preferably 550-850 deg.C for 10-40 hours, preferably 12-30 hours.

The obtained lithium-type exchanger (Li-SO) is treated with 0.10-0.40 mol/L HCl or HNO₃Preferably, 0.2-0.4 mol/L HCl is used for elution, the solution is soaked for 2-4 hours, and the hydrogen type exchanger (H-SO) is obtained after the exchange, namely the lithium ion separation material, can be recycled, SO as to directly extract and separate the low-content Li in the brine⁺The principle is as follows:

loaded adsorption of Li⁺The process is as follows:

elution of displaced Li⁺The process is as follows:

the invention is characterized in that inorganic material is adopted, and Li is infiltrated⁺Treated to obtain a material capable of only accommodating Li⁺Is/are as followsSpecial 'cavity' separating material for Li⁺In Li⁺In the process of intercalation and deintercalation, the structure of the exchanger O-Ti-O is kept stable, so that repeated lithium absorption and lithium desorption can be carried out to Li⁺The switching capacity of (a) is substantially unchanged.

The invention is further described with reference to the drawings and the examples.

Example 1

30 g of analytically pure rutile TiO₂(TiO₂Content is more than or equal to 98 percent), 31 g of high-purity Li is added₂CO₃(Li₂CO₃Not less than 99.9 percent) is added into the mixture, and the mixture is mixed for 24 hours in a ball mill and taken outCalcining the mixture for 15 to 20 hours at 650 to 800 ℃ in a muffle furnace to obtain a lithium type lithium ion exchanger, soaking the lithium type lithium ion exchanger in 200ml of HCl with the concentration of 0.2 to 0.3mol/L for 2 to 4 hours, filtering to obtain a hydrogen type lithium ion exchanger, taking 2000ml of brine with the composition shown in the table 1, adding 50 g of the hydrogen type lithium ion exchanger, soaking the brine for 4 to 5 hours under slight stirring, filtering, measuring Li in filtrate⁺Content, respectively calculating Li⁺、Mg²⁺、Ca⁺The extraction rate and the removal rate of (A). In the solid obtained by filtration, i.e. loaded with Li⁺Adding 500ml of hydrochloric acid with the concentration of 0.2-0.3 mol/L into the exchanger (lithium type exchanger), soaking for 2-4 hours under micro-stirring, filtering, and measuring Li in the filtrate⁺、Mg²⁺、Ca⁺The content of (A) in the filtrate is the separated Na²⁺、K⁺、Ca²⁺、Mg⁺The subsequent LiCl solution, directly evaporated, may be replaced by Na₂CO₃Precipitation method for preparing Li₂CO₃. The solid obtained by filtering is the hydrogen exchanger which can be recycled, and the measurement result is shown in table 2.

Example 2

30 g of analytically pure anatase TiO are taken₂(TiO₂Content is more than or equal to 98 percent), 31 g of high-purity Li is taken₂CO₃(Li₂CO₃Not less than 99.9%). Ball-milling and mixing the two solid powders, adding 90ml of a mixed solution (the proportion is 1: 3) of analytically pure absolute ethyl alcohol and water, adding 1.0ml of polyacrylamide with the concentration of 1 per thousand, stirring for 30-180 minutes, evaporating to dryness at 100 ℃ to obtain a precursor of a lithium ion exchanger, performing the following process as in example 1, and separating and extracting Li from brine (the composition is shown in table 1)⁺The results are shown in Table 2.

Example 3

37 g of analytically pure metatitanic acid (H) are taken₂TiO₃Not less than 99.5 percent) and 36 g of high-purity LiOH H₂O(LiOH·H₂The content of O is more than or equal to 99.5 percent), ball milling and mixing the two solid powders, adding 90ml of mixed solution (the mass ratio is 1: 0.3: 2) of analytically pure absolute ethyl alcohol, analytically pure ethylene glycol and water, soaking for 30-180 minutes, then evaporating to dryness at 100 ℃ to obtain a precursor of the lithium ion exchanger, and finally drying the precursor of the lithium ion exchangerCalcining the precursor in a muffle furnace at 700-800 ℃ for 15-20 hours to obtain a lithium type lithium ion exchanger, and then separating and extracting Li from brine (the composition of the brine is shown in Table 1) in the same process as in example 1⁺The results are shown in Table 2.

Example 4

40 g of the hydrogen-type lithium ion exchanger synthesized in example 2 were subjected to a column-like lithium extraction cycle test under the column-like conditions: the column diameter phi is 15mm, the filling height h is 100mm, the filling mode is free dry type filling, the brine composition is shown in table 1, the flow rate of the brine on the column is 1.5-2.0 ml/min, the total amount of the brine is 2000ml, after the adsorption process is finished, 500ml of 0.3mol/L HCl solution is used for elution, the outflow rate of eluent is 1.5 ml/min, after the elution is finished, brine lithium extraction-elution test is carried out again, the cycle is carried out for 20 times, and the result is shown in table 3.

TABLE 1 brine composition (g/L)

Li⁺	Na⁺	K⁺	Ca⁺	Mg²⁺	B₂O₃	Cl^～	Ca²⁺/Li⁺	Mg²⁺/Li⁺	PH
Li⁺	Na⁺	K⁺	Ca⁺	Mg²⁺	B₂O₃	Cl^～	Ca²⁺/Li⁺	Mg²⁺/Li⁺	PH	0.12	18.15	1.63	1.15	0.81	0.035	32.30	9.58	6.75	6.5

TABLE 2 sample lithium extraction test results in the examples

Examples of the invention Numbering	Li⁺Extraction of Percentage (%)	Ca²⁺Extraction of Percentage (%)	Mg²⁺Extraction rate (％)	Eluent Li⁺ Concentration (g/L)	Li⁺Rich in Multiple of collection	For Li⁺Saturated exchange capacity of Amount (mgLi)⁺/gTiO₂)	Dissolution loss of exchanger Percentage (%)
Examples of the invention Numbering	Li⁺Extraction of Percentage (%)	Ca²⁺Extraction of Percentage (%)	Mg²⁺Extraction rate (％)	Eluent Li⁺ Concentration (g/L)	Li⁺Rich in Multiple of collection	For Li⁺Saturated exchange capacity of Amount (mgLi)⁺/gTiO₂)	Dissolution loss of exchanger Percentage (%)	Practice of Example 1	72.50	2.41	10.90	0.3480	2.9	17.33	0.05
Practice of Example 2	98.31	0.55	1.53	0.4719	3.93	29.6	0.10	Practice of Example 1	72.50	2.41	10.90	0.3480	2.9	17.33	0.05
Practice of Example 2	98.31	0.55	1.53	0.4719	3.93	29.6	0.10	Practice of Example 3	97.0	1.04	0.87	0.4656	3.88	28.0	0.08

TABLE 3 EXAMPLESEXAMPLE 4 results of the column type cycle lithium extraction test

Item	1 st time	3 rd time	7 th time	20 th time
Item	1 st time	3 rd time	7 th time	20 th time	Li⁺Extraction ratio (%)	98.31	98.25	97.41	90.76
Ca²⁺Removal Rate (%)	99.45	99.0	98.65～2	97.07	Li⁺Extraction ratio (%)	98.31	98.25	97.41	90.76
Ca²⁺Removal Rate (%)	99.45	99.0	98.65～2	97.07	Mg²⁺Removal Rate (%)	98.47	97.72	95.95	92.72
For Li⁺Saturated exchange capacity of (mgLi⁺/gTiO₂)	29.6	28.30	26.11	24.52	Mg²⁺Removal Rate (%)	98.47	97.72	95.95	92.72
For Li⁺Saturated exchange capacity of (mgLi⁺/gTiO₂)	29.6	28.30	26.11	24.52	Dissolution loss Rate (%)	0.10	0.15	0.17	3.83

Claims

1. A method for synthesizing lithium ion separation material for extracting and separating lithium from brine with low lithium content, such as salt lake brine and underground brine. Characterized in that the lithium ion material is TiO₂Or H₂TiO₃As starting material, the lithium source is Li₂CO₃、LiOH·H₂O or LiNO₃Adding lithium in a molar ratio of Li to Ti of 1.05-1.15: 2.0, adding an organic solvent with the carbon number lower than 13 into the starting material and a lithium source, mixing the mixture with water to form a mixed solution, wherein the organic solvent is one or a mixture of alcohols and ketones, mutually diffusing reaction substances under the action of stirring and impregnation to achieve molecular level mixing and form a sol-like state, evaporating and drying to form an exchanger precursor, and calcining the precursor at 500-1000 ℃ for 10-40 hours to obtain the precursor with the stoichiometric Li_XTiO₃The lithium type exchanger has X more than or equal to 1 and less than 2, and is eluted and transformed into a hydrogen type exchanger by using HCl of 0.1-0.5 mol/L.

2. The method of claim 1, wherein the solution used for the impregnation is an organic solvent containing less than 13 carbon atoms. And the mixed solution is composed of water and one or two of alcohols and ketones, the mass ratio of the organic solvent to the water is 1: 0-0.8, and the addition amount of the mixed solution is 1: 0.8-3.0 according to the solid-liquid mass ratio.

3. The method of claim 1 or 2, wherein the whole mixing process is carried out at room temperature, the reaction time is 0.5-3 hours, the reaction materials are fully diffused by stirring and impregnation to achieve molecular mixing, so that the system reactants are in a sol-like state, and are evaporated to dryness at 80-110 ℃, or are spray-dried at 110-250 ℃ to form a precursor of the lithium ion exchanger.

4. The method of claim 3, wherein the precursor is calcined at 500-1000 ℃ for 10-40 hours, then naturally cooled, ground into powder, eluted with 0.1-0.5 mol/L HCl, soaked for 2-4 hours, and then transformed to prepare the hydrogen-type inorganic lithium ion separation material.