CN116196882A - Preparation method of titanium series lithium ion sieve - Google Patents

Abstract

The invention provides a preparation method of a titanium-based lithium ion sieve, which belongs to the technical field of ion sieves. Potassium acetate is used as a potassium source, beaten together with metatitanic acid, dried, and roasted at a high temperature to prepare a potassium metatitanate precursor; Quality potassium metatitanate precursor, adding hydrochloric acid eluent for elution, adding hydrochloric acid solution during the elution process to keep the pH value of the slurry between 1.3-2.0; stop adding acid after the pH of the slurry remains stable; the obtained slurry After centrifugation and washing, the obtained solid was dried and pulverized to obtain H ₂ TiO ₃ . In the present invention, potassium salt is used to replace the lithium source, and the selectivity of the synthesized lithium ion sieve to lithium ions does not decrease. Under the condition of ensuring that the selectivity does not decrease, the interlayer distance is moderately widened, the adsorption capacity is large, the cycle performance is stable, and the synthesis cost is reduced. , suitable for industrial production; solves the problems of high preparation cost, low adsorption capacity and slow adsorption rate of titanium-based lithium adsorbents.

Description

Preparation method of titanium series lithium ion sieve

technical field

The invention relates to the technical field of ion sieves, in particular to a method for preparing a titanium-based lithium ion sieve with high adsorption capacity and low cost.

Background technique

As the lightest metal element in nature, lithium has high utilization value and broad application fields due to its excellent physical and chemical properties. Lithium and its salts and their compounds are widely used in chemical industry, glass, ceramics, aerospace, new energy and other fields, making the development and utilization of lithium resources a hot spot.

There are two main methods for synthesizing ion sieve precursors, solid-phase method and liquid-phase method. The high-temperature solid-phase method is one of the most commonly used methods for preparing ion sieve precursors. It mainly involves solid-state reaction of fusible and easily decomposed salts at high temperatures to form oxides. Two salts with different ions are separated, Melting, fusion, and continuous interaction to form powders with small particle sizes. After the required powder is synthesized, the ion sieve is prepared by the adsorption method. The adsorption method has the characteristics of high selectivity, can handle brine with low lithium content, and can realize clean production. The process is simple and the recovery rate is high. It is very suitable for extraction from salt lake water lithium.

Titanium-based lithium-ion sieve adsorbent is a highly selective adsorption material for lithium ions. The synthesis of titanium-based lithium-ion sieves generally uses lithium sources (lithium-containing compounds) and titanium sources (titanium-containing compounds) as raw materials, but lithium Salt is expensive, resulting in too high industrial production costs of titanium-based lithium ion sieves. Therefore, it is necessary to adjust the raw materials to prepare adsorbents with low cost, high adsorption, low dissolution loss and high cycle performance.

Contents of the invention

The object of the present invention is to provide a method for preparing a titanium-based lithium ion sieve with high adsorption capacity and low cost, so as to solve at least one technical problem in the above-mentioned background technology.

In order to achieve the above object, the present invention has taken the following technical solutions:

The invention provides a preparation method of titanium series lithium ion sieve, comprising:

Potassium acetate is used as a potassium source, beaten with metatitanic acid, dried, and roasted at high temperature to prepare a potassium metatitanate precursor;

Take a certain mass of potassium metatitanate precursor, add hydrochloric acid eluent to elute, and add hydrochloric acid solution during the elution process to keep the pH value of the slurry between 1.3-2.0;

Stop adding acid after the pH of the slurry remains stable;

The obtained slurry is centrifuged and washed, and the obtained solid is dried and pulverized to obtain H ₂ TiO ₃ .

Preferably, metatitanic acid and anatase TiO ₂ are added to the potassium acetate solution, then PEG200 is added to mix well, ultrasonically treated in a water bath, dried, ground, and calcined to obtain a K ₂ Ti ₆ O ₁₃ precursor.

Preferably, 50-100 g of potassium acetate is added to 200 ml of deionized water, stirred at room temperature until dissolved to obtain a potassium acetate solution.

Preferably, 110-240 g of metatitanic acid and 45-50 g of anatase TiO ₂ are added to the potassium acetate solution.

Preferably, the quality of adding PEG200 is 4-10g.

Preferably, 50-60°C water temperature is ultrasonically treated for 20-30min, and the oven is dried at 110-130°C for 6h-10h. After fully drying, the sample is taken out and transferred into a crucible for grinding.

Preferably, after grinding, it is transferred into a muffle furnace, and the temperature is raised for calcination. The temperature rise rate is 2-10°C/min, first raised to 500-650°C, calcined for 4-8h, and then raised to 700-900°C for 4-8h. A K ₂ Ti ₆ O ₁₃ precursor with high specific surface area, large adsorption capacity and high selectivity is obtained.

Preferably, take a certain mass of potassium metatitanate precursor, add 0.05-0.1mol/L hydrochloric acid eluent, keep the feeding ratio at 10-20g/L, and shake and elute at 50-60°C for 1-2h.

Preferably, 0.5-2 mol/L hydrochloric acid solution is added during the elution process to keep the pH value of the slurry between 1.3-2.0, and the acid solution is changed twice in the middle to prevent the K ⁺ concentration from being too high to cause back absorption.

Preferably, the addition of acid is stopped after the pH of the slurry remains stable, the obtained slurry is centrifuged and washed 4-5 times, and the obtained solid is dried in an oven at 50-60°C and pulverized to obtain H ₂ TiO ₃ .

Beneficial effects of the present invention: the lithium source is replaced by potassium salt, and the selectivity of the lithium ion sieve after synthesis to lithium ions does not decrease. Under the condition of ensuring that the selectivity does not decrease, the interlayer distance is moderately widened, the adsorption capacity is large, and the cycle performance is stable. The method reduces the synthesis cost and is suitable for industrial production; it solves the problems of high preparation cost, low adsorption capacity and slow adsorption rate of titanium-based lithium adsorbents.

Advantages of additional aspects of the invention will become apparent from the description hereinafter, or may be learned by practice of the invention.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Fig. 1 is a flowchart for preparing the potassium metatitanate precursor described in the embodiment of the present invention.

Fig. 2 is the XRD spectrum of the obtained precursor described in Example 1 of the present invention.

FIG. 3 is a schematic diagram of scanning electron microscopy of the precursor obtained in Example 1 of the present invention.

FIG. 4 is a schematic diagram of the Li ⁺ adsorption rate curve described in Example 1 of the present invention.

Fig. 5 is a schematic diagram of the influence of the number of cycles on the Li ⁺ adsorption amount described in Example 1 of the present invention.

Fig. 6 is the XRD spectrum of the obtained precursor described in Example 2 of the present invention.

Fig. 7 is a schematic diagram of scanning electron microscopy of the obtained precursor described in Example 2 of the present invention.

Fig. 8 is a schematic diagram of the Li ⁺ adsorption rate curve described in Example 2 of the present invention.

Fig. 9 is a schematic diagram showing the effect of the number of cycles on the Li ⁺ adsorption amount described in Example 2 of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with the drawings are exemplary, and are only used to explain the present invention, but not to be construed as limiting the present invention.

Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It should also be understood that terms such as those defined in commonly used dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and unless defined as herein, are not to be interpreted in an idealized or overly formal sense explain.

Those skilled in the art will understand that unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the word "comprising" used in the description of the present invention refers to the presence of said features, integers, steps, operations, elements and/or components, but does not exclude the presence or addition of one or more other features, Integers, steps, operations, elements and/or groups thereof.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

In order to facilitate the understanding of the present invention, the present invention will be further explained below with specific embodiments in conjunction with the accompanying drawings, and the specific embodiments are not intended to limit the embodiments of the present invention.

Those skilled in the art should understand that the drawings are only schematic diagrams of the embodiments, and the components in the drawings are not necessarily necessary for implementing the present invention.

As shown in Figure 1, in this embodiment, a low-cost, high adsorption capacity, high selectivity and high adsorption rate titanium-based lithium ion sieve preparation method is provided as follows:

Preparation of the titanium-based lithium ion sieve precursor: Potassium acetate was used as the potassium source, beaten together with metatitanic acid, dried, and roasted at high temperature to prepare the potassium metatitanate precursor.

The preparation of the titanium-based lithium ion sieve precursor specifically includes: adding 55-100g of potassium acetate to 200ml of deionized water, stirring at room temperature until dissolved, slowly adding 111-238g of metatitanic acid and 45-50g of anatase TiO ₂ Add 4-10g of PEG200 to the above solution, mix thoroughly, ultrasonically treat at 50-60°C for 20-30min, dry in an oven at 110-130°C for 6h-10h, take out the sample after fully drying, and transfer it to a crucible. After fully grinding, transfer to a muffle furnace and use temperature programming for calcination. The temperature rise rate is 2-10°C/min, first rise to 500-650°C, calcined for 4-8h, and then rise to 700-900°C for 4- 8h, thus obtaining the K ₂ Ti ₆ O ₁₃ precursor with high specific surface area, large adsorption capacity and high selectivity.

Add a certain mass of precursors into the beaker, add 0.05-0.1mol/L hydrochloric acid eluent respectively, keep the feeding ratio at 10-20g/L, shake and elute at 50-60°C for 1-2h, during the process use 0.5-2mol/L hydrochloric acid solution is added to keep the pH value of the slurry between 1.3-2.0, and the acid solution is changed twice in the middle to prevent the K ⁺ concentration from being too high to cause back absorption. Stop adding acid after the pH of the slurry remains stable. The obtained slurry is centrifuged and washed 4-5 times, and the obtained solid is dried in an oven at 50-60° C. and then pulverized to obtain a titanium-based lithium ion sieve of H ₂ TiO ₃ .

Example 1

Add 55g of potassium acetate into 200ml of deionized water, and stir until dissolved at room temperature. Add 111g of metatitanic acid and 45g of anatase _TiO2 to the above solution, add 4g of PEG200 into the beaker containing the sample and mix thoroughly, ultrasonically treat at 50°C for 20min, and dry in an oven at 110°C for 10h. After fully drying, take the sample out, transfer it to a crucible, and after fully grinding it, transfer it to a muffle furnace and use a temperature program for calcination at a rate of 4°C/min. Calcined at 700°C for 8 hours, cooled and ground to obtain a K ₂ Ti ₆ O ₁₃ precursor with high specific surface area, large adsorption capacity and high selectivity. The XRD spectrum of the precursor obtained in this example is shown in Figure 2, compared with the standard card PDF#74-0275, the obtained precursor is K ₂ Ti ₆ O ₁₃ . The microscopic morphology of the precursor K ₂ Ti ₆ O ₁₃ is shown in Figure 3, and it can be seen that the obtained precursor is nano-scale particles with uniform particle size distribution.

Add a certain amount of precursor to the beaker, add 0.05mol/L hydrochloric acid eluent respectively, keep the feeding ratio at 20g/L, shake and elute at 50°C for 1 hour, and add 2mol/L hydrochloric acid solution during the process Keep the pH value of the slurry between 1.3-2.0, and change the acid solution twice in the middle to prevent the K ⁺ concentration from being sucked back when the concentration is too high. Stop adding acid after the pH of the slurry remains stable. The obtained slurry was centrifuged and washed 4 times, and the obtained solid was dried in an oven at 50° C. and then pulverized to obtain H ₂ TiO ₃ .

Li ⁺ adsorption performance test: using 1L of laboratory self-made brine (containing lithium chloride (4.45g), sodium silicate nonahydrate (0.21g), anhydrous sodium sulfate (84.92g), anhydrous sodium carbonate (15.57g) , sodium chloride (28.39g), calcium chloride (0.19g), magnesium chloride (8.93g), potassium chloride (12.78g)), the adsorption performance was tested. Take 20g of the titanium-based lithium ion sieve in Example 1 and soak it in 1L of brine prepared in the laboratory for continuous stirring. Take a water sample every 20 minutes, and test the Li ⁺ content in it by ICP. When the Li ⁺ content in the water sample no longer changes, it will be adsorption equilibrium. The adsorption rate curve is shown in Figure 4. When the adsorption reaches equilibrium for 140 minutes, the equilibrium adsorption capacity is 31 mg/g, which proves that the titanium-based lithium ion sieve has a high adsorption capacity.

Take 2g of the adsorbed lithium adsorbent in Case 1, keep the feeding ratio of 20g/L, analyze the adsorbed sample, use 0.1mol/L hydrochloric acid solution as the analysis solution, take a sample every half an hour, and test the Li in it by ICP ⁺ , K ⁺ , Ca ²⁺ , Na ⁺ , Mg ²⁺ content and selectivity data are shown in Table 1. It can be concluded from Table 1 and Table 2 that the lithium adsorbent obtained by replacing the lithium source with potassium salt still has high selectivity.

Table 1 Experimental Case 1 The ion concentrations of the original adsorption solution and the analysis solution

Table 2 Experimental Case 1 The ion concentration ratio of the analytical solution

The recycling performance of materials has a great influence on the operating cost of industrial operations. Therefore, the experiment on the cyclic adsorption performance of lithium-ion sieves is shown in Figure 5. The adsorption performance of 9 cycles fluctuates in the range of 29.5-31mg/g, and there is no The sharp attenuation of the adsorption capacity shows that the titanium-based lithium-ion sieve adsorbent obtained by this experimental method has good circulation, and this performance ensures that the titanium-based lithium-ion sieve can achieve stable operation of the system during actual use.

Example 2

Add 100 g of potassium acetate into 200 ml of deionized water, and stir until dissolved at room temperature. Slowly add 238g of metatitanic acid and 50g of anatase TiO ₂ into the above solution, add 10g of PEG200 into the beaker containing the sample and mix thoroughly, ultrasonically treat at 60°C for 30min, and dry in an oven at 130°C for 6h. The sample was taken out, transferred to a crucible, and after being fully ground, transferred to a muffle furnace for calcination by temperature programming at a rate of 5°C/min to 650°C for 8 hours, and then to 900°C for 4 hours. Cooling, crushing and grinding to obtain the K ₂ Ti ₆ O ₁₃ precursor with high specific surface area, large adsorption capacity and high selectivity. The XRD spectrum of the precursor obtained in Example 2 is shown in Fig. 6, compared with the standard card PDF#74-0275, the obtained precursor is K ₂ Ti ₆ O ₁₃ . The microscopic morphology of the precursor K ₂ Ti ₆ O ₁₃ is shown in FIG. 7 , and it can be seen that the obtained precursor is nano-scale particles with uniform particle size distribution.

Add a certain mass of precursors into the beaker, add 0.1mol/L hydrochloric acid eluent respectively, keep the feeding ratio at 10g/L, stir and elute at 60°C for 2 hours, and supplement with 0.5mol/L hydrochloric acid solution during the process Plus keep the pH value of the slurry between 1.3-2.0, and change the acid solution twice in the middle to prevent the K ⁺ concentration from being too high to cause back absorption. Stop adding acid after the pH of the slurry remains stable. The obtained slurry was centrifuged and washed 5 times, and the obtained solid was dried in an oven at 60° C. and then pulverized to obtain H ₂ TiO ₃ .

Li ⁺ adsorption performance test: The adsorption performance was tested with self-prepared brine in the laboratory, and the components and dosages in the self-prepared brine were the same as those in Example 1. Take 10g of the lithium adsorbent in Example 1 and soak it in 1L of brine prepared in the laboratory and keep stirring. Take a water sample every 20 minutes, and test the Li ⁺ content in it by ICP. When the Li ⁺ content in the water sample does not change anymore, it is the adsorption equilibrium . The adsorption curve is shown in Figure 8, when the adsorption reaches equilibrium after 120 minutes of adsorption, the equilibrium adsorption capacity is 35 mg/g, which proves that the titanium-based lithium ion sieve has a high adsorption capacity.

Take 2g of the adsorbed lithium adsorbent in Case 2, keep the feed ratio at 10g/L, analyze the adsorbed sample, use 0.1mol/L hydrochloric acid solution as the analysis solution, take a sample every half an hour, and pass the ICP test. Li ⁺ , K ⁺ , Ca ²⁺ , Na ⁺ , Mg ²⁺ content and selectivity data are shown in Table 3. It can be seen from Table 3 and Table 4 that the lithium adsorbent obtained by replacing the lithium source with potassium salt has high selectivity.

Table 3 Experimental Case 2 The ion concentration of the adsorption stock solution and the analysis solution

Table 4 Experimental Case 2 The ion concentration ratio of the analytical solution

The recycling performance of materials has a great influence on the operating cost of industrial operations. Therefore, the experiment on the cyclic adsorption performance of lithium-ion sieves is shown in Figure 9. The adsorption performance fluctuates in the range of 34-35.2 mg/g after 9 cycles. There is no sharp attenuation of the adsorption capacity, which shows that the titanium-based lithium-ion sieve adsorbent obtained by this experimental method has good circulation, and this performance ensures that the titanium-based lithium-ion sieve can achieve stable operation of the system during actual use.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solutions disclosed in the present invention, those skilled in the art do not need to pay Various modifications or deformations that can be made through creative labor shall be covered within the scope of protection of the present invention.

Claims (10)

1. a preparation method of titanium series lithium ion sieve, is characterized in that, comprises: Potassium acetate is used as a potassium source, beaten with metatitanic acid, dried, and roasted at high temperature to prepare a potassium metatitanate precursor; Take a certain mass of potassium metatitanate precursor, add hydrochloric acid eluent to elute, and add hydrochloric acid solution during the elution process to keep the pH value of the slurry between 1.3-2.0; Stop adding acid after the pH of the slurry remains stable; The obtained slurry is centrifuged and washed, and the obtained solid is dried and pulverized to obtain H ₂ TiO ₃ . 2. The preparation method of titanium series lithium ion sieve according to claim 1, is characterized in that, in potassium acetate solution, add metatitanic acid and anatase type TiO ₂ , then add PEG200 and fully mix, water bath ultrasonic treatment, bake Dry, grind, and calcinate to obtain the K ₂ Ti ₆ O ₁₃ precursor. 3. The preparation method of the titanium-based lithium ion sieve according to claim 2, characterized in that 50-100g of potassium acetate is added to 200ml of deionized water, stirred at normal temperature until dissolved to obtain methyl acetate solution. 4 . The preparation method of titanium-based lithium ion sieve according to claim 3 , characterized in that 110-240 g of metatitanic acid and 45-50 g of anatase TiO ₂ are added to the methyl acetate solution. 5. The preparation method of the titanium series lithium ion sieve according to claim 4, characterized in that, the quality of adding PEG200 is 4-10g. 6. The preparation method of titanium-based lithium ion sieve according to claim 5, characterized in that, ultrasonic treatment at 50-60°C water temperature for 20-30min, drying in an oven at 110-130°C for 6h-10h, and drying the sample fully Take it out and transfer it to a crucible for grinding. 7. The preparation method of the titanium-based lithium ion sieve according to claim 6, characterized in that, after being ground, it is transferred to a muffle furnace, and the temperature is raised for calcination, and the temperature rise rate is 2-10° C./min and first rises to 500-650° C. , calcined for 4-8h, and then raised to 700-900°C for 4-8h to obtain a K ₂ Ti ₆ O ₁₃ precursor with high specific surface area, large adsorption capacity and high selectivity. 8. the preparation method of titanium series lithium ion sieve according to claim 1 is characterized in that, get the potassium metatitanate precursor of certain quality, add the hydrochloric acid eluent of 0.05-0.1mol/L, keep feeding ratio at 10-20g/L, eluted by shaking at 50-60℃ for 1-2h. 9. The preparation method of the titanium series lithium ion sieve according to claim 8, characterized in that 0.5-2mol/L hydrochloric acid solution is added during the elution process to keep the pH value of the slurry between 1.3-2.0, and the pH value is changed between 1.3-2.0. Twice the acid solution, in case the K ⁺ concentration is too high to cause suck back. 10. the preparation method of titanium series lithium ion sieve according to claim 9 is characterized in that, stop adding acid after the pH of the slurry remains stable, the slurry obtained is centrifuged, and washed 4-5 times, and the obtained solid is released After drying in an oven at 50-60°C, it is pulverized to obtain H ₂ TiO ₃ .

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