Method for preparing manganese lithium ion sieve by using ozone

Abstract

The invention discloses a method for preparing a manganese lithium ion sieve by using ozone, which comprises the following steps of: introducing ozone into a solution containing bivalent manganese salt and lithium salt, reacting to obtain a lithium manganese oxide intermediate LiMnO2, and calcining and annealing the lithium manganese oxide intermediate to obtain a manganese lithium ion sieve precursor. The manganese-series lithium ion sieve precursor is subjected to lithium removal transformation in an acid solution to obtain the manganese-series lithium ion sieve, and the manganese-series lithium ion sieve can be used for selectively adsorbing lithium ions from a lithium-containing solution. According to the method, dangerous strong oxidants such as potassium permanganate, hydrogen peroxide and persulfate can be prevented from being used, and the effects of safety, energy conservation and cost reduction are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of inorganic synthetic adsorbents, and particularly relates to the preparation of manganese oxides in a low valence state, products, and the application of synthesizing a lithium ion sieve precursor. Background Art

[0002] Lithium is the lightest and smallest alkali metal in nature, with active chemical properties. Lithium and its compounds are widely used in many fields such as aviation, medicine, chemical industry, national defense, and new energy, and are known as "important elements driving the progress of the world".

[0003] Lithium resources mainly exist in the form of ions in salt lake brines in large quantities, but their concentration is relatively low. Therefore, it is necessary to use lithium adsorbents to selectively extract lithium from liquid-phase resources. Preparing a lithium adsorbent with high adsorption capacity, high selectivity, and strong anti-interference ability is one of the core key technologies in the lithium extraction technology by adsorption method. Among many lithium adsorbents, the lithium ion sieve prepared from a lithium-rich manganese-based lithium ion sieve precursor has attracted much attention due to its theoretical adsorption capacity. Usually, the way to prepare a manganese-based lithium ion sieve precursor is as follows: reacting an inorganic oxidant (such as potassium permanganate, persulfate, hydrogen peroxide, etc.) with a divalent manganese salt to obtain a lithium manganese oxide intermediate LiMnO 2 , and then roasting the lithium manganese oxide intermediate LiMnO 2 in an oxidizing atmosphere to form a manganese-based lithium ion sieve precursor.

[0004] However, the above inorganic oxidants are relatively dangerous to use in industrial production, have high costs, and a large amount of wastewater will be generated during the production process, which is not conducive to the industrial application of manganese-based lithium ion adsorbents. Therefore, how to prepare manganese-based lithium ion sieves safely, energy-efficiently, and at low cost has been an issue that the industry has been exploring and solving. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention discloses a method for preparing a manganese-based lithium ion sieve using ozone. This method uses ozone as an oxidant and can prepare a manganese-based lithium ion sieve safely, energy-efficiently, and at low cost.

[0006] To achieve the above invention objective, the present invention adopts the following technical solutions:

[0007] A method for preparing a manganese-based lithium ion sieve using ozone: It includes:

[0008] Step 1: Mix ozone with a solution containing a divalent manganese salt and a lithium salt, and react to obtain a lithium manganese oxide intermediate LiMnO 2 ;

[0009] Step 2: Subject the lithium manganese oxide intermediate LiMnO 2 to calcination and annealing treatment to obtain a manganese-based lithium ion sieve precursor;

[0010] Step 3: The manganese-based lithium ion sieve precursor is delithiated and transformed with an acid solution to obtain a manganese-based lithium ion sieve.

[0011] The mixing in Step 1 is to first mix ozone with a solution containing a divalent manganese salt to react and produce manganese oxide MnOOH, and then mix the manganese oxide MnOOH with a solution containing a lithium salt to react and produce a lithium manganese oxide intermediate LiMnO 2。

[0012] The mixing in Step 1 is to directly mix ozone with a solution containing a divalent manganese salt and a lithium salt to react and produce a lithium manganese oxide intermediate LiMnO 2 。

[0013] The divalent manganese salt is selected from halide salts, sulfates, nitrates, carbonates, phosphates, and hydroxides of divalent manganese.

[0014] The lithium salt is selected from halide salts, sulfates, nitrates, carbonates, phosphates, and hydroxides of lithium.

[0015] The temperature of the calcination and annealing treatment is 100 - 1000 °C, and the time is 1 - 100 h.

[0016] The manganese-based lithium ion sieve precursor is Li 1.6 Mn 1.6 O 4 、Li 1.33 Mn 1.67 O 4 、Li 4 Mn 5 O 12 、Li 2 MnO 3 、LiMn 2 O 4 、Li x Mn y O 4 (where 0 < x, y < 2), or a mixture of several of them.

[0017] The acid solution is selected from organic acids and inorganic acids.

[0018] The acid solution is selected from one or a mixture of sulfuric acid, hydrochloric acid, nitric acid, citric acid, acetic acid, and phosphoric acid.

[0019] Beneficial effects

[0020] The present invention provides a new method for preparing a manganese-based lithium ion sieve. Compared with the prior art, the present invention avoids using dangerous strong oxidants such as potassium permanganate, hydrogen peroxide and persulfates, achieving the effects of safety, energy conservation and cost reduction. Moreover, the manganese-based lithium ion sieve prepared by the present invention has good lithium ion selectivity and extremely high application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the process flow chart for preparing the manganese-based lithium ion sieve in Example 1 of the present invention;

[0022] Figure 2 is the process flow chart for preparing the manganese-based lithium ion sieve in Example 2 of the present invention;

[0023] Figure 3 is the process flow chart for preparing the manganese-based lithium ion sieve in Example 3 of the present invention;

[0024] Figure 4 is the XRD pattern of the precursor of the manganese-based lithium ion sieve prepared in Examples 1 to 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0026] Example 1

[0027] Take 14.82 grams of manganese sulfate, add 100 milliliters of pure water, dissolve the manganese sulfate, then introduce 2.36 grams of ozone. After full reaction, manganese oxide MnOOH is obtained. Take 8.63 grams of manganese oxide MnOOH, mix it with 2.35 grams of lithium hydroxide, and then place it in a hydrothermal reaction kettle and react at 120 °C for 24 hours to prepare a lithium manganese oxide intermediate LiMnO 2 , then take 9.22 grams of LiMnO 2 , and calcine it in an air atmosphere at 400 °C for 12 hours. The precursor of the manganese-based lithium ion sieve Li 1.6 Mn 1.6 O 4 is obtained, and its XRD pattern is as shown in Figure 3 . Take 2 grams of the precursor of the manganese-based lithium ion sieve Li 1.6 Mn 1.6 O 4 , take 200 mL of 0.075 mol / L sulfuric acid, and transform Li 1.6 Mn 1.6 O 4 for 1 h to prepare the manganese-based lithium ion sieve MnO 2 ·0.5H 2 O. Then take 2 grams of the manganese-based lithium ion sieve MnO 2 ·0.5H 2The adsorption and desorption experiments were carried out on the actual brine, and the ion contents in the desorbed solution are shown in Table 1.

[0028] Table 1 Ion contents of brine and desorbed solution in the desorbed solution after adsorption of the sample in Example 1

[0029] g / L Lithium ion Sodium ion Potassium ion Calcium ion Magnesium ion Brine 0.248 64.650 10.920 0.494 32.900 Desorbing solution 0.578 0.317 0.053 0.117 0.161

[0030] As can be seen from Table 1, the sodium / lithium of the brine is 260, potassium / lithium is 44, and magnesium / lithium is 133. Using the manganese-based lithium ion sieve MnO obtained in Example 1 2 ·0.5H 2 O, after the actual brine is adsorbed and desorbed, the sodium / lithium of the desorbed solution is 0.5, potassium / lithium is 0.09, and magnesium / lithium is 0.27, indicating that the manganese-based lithium ion sieve prepared by ozone has good lithium ion selectivity.

[0031] Example 2

[0032] Take 14.82 grams of manganese sulfate and 4.7 grams of lithium hydroxide, add 100 ml of pure water, dissolve manganese sulfate and lithium hydroxide, then introduce 2.36 grams of ozone. After full reaction, the lithium manganese oxide intermediate LiMnO is obtained 2 , and then take 18 grams of LiMnO 2 , in an air atmosphere at 450 °C, calcine for 18 hours. The manganese-based lithium ion sieve precursor Li 1.6 Mn 1.6 O 4 is obtained, and its XRD pattern is as shown in Figure 3 . Take 2 grams of the manganese-based lithium ion sieve precursor Li 1.6 Mn 1.6 O 4 , take 200 mL of 0.075 mol / L sulfuric acid, transform Li 1.6 Mn 1.6 O 4 for 1 h to prepare the manganese-based lithium ion sieve MnO 2 ·0.5H 2 O. Then take 2 grams of the manganese-based lithium ion sieve MnO 2 ·0.5H 2 O to conduct adsorption and desorption experiments on the actual brine, and the ion contents in the desorbed solution are shown in Table 2.

[0033] Table 2 Ion contents of brine and desorbed solution in the desorbed solution after adsorption of the sample in Example 2

[0034] g / L Lithium ion Sodium ion Potassium ion Calcium ion Magnesium ion Brine 0.235 68.700 10.460 0.470 31.210 Desorbing solution 0.499 0.315 0.072 0.139 0.179

[0035] As can be seen from Table 2, the sodium / lithium of the brine is 292, potassium / lithium is 44, and magnesium / lithium is 133. Using the manganese-based lithium ion sieve MnO obtained in Example 1 2·0.5H 2 After the actual brine adsorption and desorption, the sodium / lithium in the desorbed solution is 0.6, the potassium / lithium is 0.14, and the magnesium / lithium is 0.36, indicating that the manganese-based lithium ion sieve prepared by ozone has good lithium ion selectivity.

[0036] Example 3

[0037] Take 12.35 g of manganese sulfate, add 100 mL of pure water, dissolve manganese chloride, then introduce 2.36 g of ozone. After full reaction, manganese oxide MnOOH is obtained. Take 8.63 g of manganese oxide MnOOH, mix it with 2.35 g of lithium hydroxide, and then place it in a hydrothermal reaction kettle and react at 160 °C for 24 hours to prepare the lithium manganese oxide intermediate LiMnO 2 , then take 9.22 g of LiMnO 2 , and calcine it in an air atmosphere at 500 °C for 18 hours. The manganese-based lithium ion sieve precursor Li 1.6 Mn 1.6 O 4 is obtained, and its XRD pattern is as shown in Figure 3 . Take 2 g of the manganese-based lithium ion sieve precursor Li 1.6 Mn 1.6 O 4 , take 200 mL of 0.08 mol / L sulfuric acid, and transform Li 1.6 Mn 1.6 O 4 for 1 h to prepare the manganese-based lithium ion sieve MnO 2 ·0.5H 2 O. Then take 2 g of the manganese-based lithium ion sieve MnO 2 ·0.5H 2 O to conduct an adsorption and desorption experiment on the actual brine, and the ion content in the desorbed solution is shown in Table 3.

[0038] Table 3 Ion contents of brine and desorbed solution in the desorbed solution after adsorption of the sample in Example 3

[0039] g / L Lithium ion Sodium ion Potassium ion Calcium ion Magnesium ion Brine 0.241 66.675 10.690 0.482 32.055 Desorbing solution 0.539 0.316 0.063 0.128 0.170

[0040] As can be seen from Table 3, the sodium / lithium of the brine is 277, the potassium / lithium is 45, and the magnesium / lithium is 133. Using the manganese-based lithium ion sieve MnO 2 ·0.5H 2 O obtained in Example 1, after the actual brine adsorption and desorption, the sodium / lithium in the desorbed solution is 0.58, the potassium / lithium is 0.12, and the magnesium / lithium is 0.32, indicating that the manganese-based lithium ion sieve prepared by ozone has good lithium ion selectivity.

Claims

1. A method for preparing a manganese-based lithium ion sieve using ozone, characterized in that, it includes the following steps: Step 1, mix ozone with a solution containing a divalent manganese salt and a lithium salt, and react to obtain a lithium manganese oxide intermediate LiMnO 2 ; Step 2, subject the lithium manganese oxide intermediate LiMnO 2 to calcination annealing treatment to obtain a manganese-based lithium ion sieve precursor; Step 3: Carry out delithiation transformation on the manganese-based lithium ion sieve precursor with an acid solution to obtain a manganese-based lithium ion sieve.

2. The method according to claim 1, characterized in that The mixing in the step 1 is to first mix ozone with a solution containing divalent manganese salt to react and produce manganese oxide MnOOH, and then mix the manganese oxide MnOOH with a solution containing lithium salt to react and produce a lithium manganese oxide intermediate LiMnO 2。 3. The method according to claim 1, characterized in that The mixing in the said step 1 is to directly mix ozone with the solution containing divalent manganese salt and lithium salt, and react to obtain the lithium manganese oxide intermediate LiMnO 2 .

4. The method according to claim 1, characterized in that, the divalent manganese salt is selected from halide salts, sulfates, nitrates, carbonates, phosphates, and hydroxides of divalent manganese.

5. The method according to claim 1, characterized in that, the lithium salt is selected from halide salts, sulfates, nitrates, carbonates, phosphates, and hydroxides of lithium.

6. The method according to claim 1, characterized in that, the temperature of the calcination and annealing treatment is 100 - 1000 °C, and the time is 1 - 100 h.

7. The method according to claim 1, characterized in that, The described manganese-based lithium-ion sieve precursor is Li 1.6 Mn 1.6 O 4 、Li 1.33 Mn 1.67 O 4 、Li 4 Mn 5 O 12 、Li 2 MnO 3 、LiMn 2 O 4 、Li x Mn y O 4 (where 0 < x, y < 2), or a mixture of several of them.

8. The method according to claim 1, characterized in that, the acid solution is selected from organic acids and inorganic acids.

9. The method according to claim 1, characterized in that, the acid solution is selected from one or several mixtures of sulfuric acid, hydrochloric acid, nitric acid, citric acid, acetic acid, and phosphoric acid.

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