Method for preparing zinc ion adsorbent from alkali hydrothermal modified lepidolite residue
By using alkaline water thermal modification to treat lepidolite slag, a highly efficient zinc ion adsorbent was prepared, which solved the problem of poor zinc ion adsorption performance of lepidolite slag and realized the high-value utilization and environmental protection of lepidolite slag.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YICHUN JIANGLI LITHIUM BATTERY NEW ENERGY IND RES INST
- Filing Date
- 2026-02-13
- Publication Date
- 2026-06-05
AI Technical Summary
The existing lithium mica slag has poor adsorption performance for zinc ions, and it needs to be modified to improve its adsorption capacity in order to achieve high-value utilization and environmental protection of lithium mica slag.
The lithium mica slag was modified using an alkaline hydrothermal modification method, which included drying, grinding, mixing with NaOH solution and then performing hydrothermal modification in a micro reactor. The adsorbent was then prepared by circulating water vacuum filtration, drying and grinding.
It improved the zinc ion adsorption rate to 86.9%~99.9%, solved the pollution problem of lithium mica slag stockpiling, and achieved low-cost and high-efficiency zinc ion removal.
Smart Images
Figure CN122141597A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of comprehensive resource utilization and water treatment technology, and in particular to a method for preparing zinc ion adsorbent from alkaline thermally modified lithium mica slag. Background Technology
[0002] With rapid industrial development, heavy metal pollution has become one of the most serious problems facing the water environment. Zinc ions, as a typical heavy metal pollutant, are widely found in industrial wastewater from electroplating, metallurgy, and battery manufacturing, disrupting the ecological balance of aquatic bodies and accumulating through the food chain to harm human health. Currently, methods for removing zinc ions from water mainly include chemical precipitation, ion exchange, membrane separation, and adsorption. Among these, adsorption is widely used due to its advantages such as simple operation, low cost, high efficiency, and no secondary pollution.
[0003] Lepidolite is an important lithium resource. The lithium extraction process from lepidolite generates a large amount of lepidolite slag. If not properly treated, this slag not only occupies land resources but may also cause environmental pollution due to the leaching of harmful substances. Therefore, realizing the high-value utilization of lepidolite slag has significant economic and environmental benefits. Preparing lepidolite slag into adsorbents for the removal of heavy metal ions from water is one effective way to achieve its resource utilization.
[0004] However, the original lepidolite smelting slag exhibits poor adsorption performance for zinc ions, necessitating modification to enhance its adsorption capacity. Alkaline hydrothermal modification can alter the surface properties and pore structure of the material through high temperature, high pressure, and an alkaline environment, promoting lattice reconstruction and the generation of active sites, thereby improving adsorption performance. Therefore, developing an alkaline hydrothermal modified adsorbent based on lepidolite slag for the efficient removal of zinc ions from water has significant research value and application prospects. Summary of the Invention
[0005] To address the aforementioned technical problems in the existing technology, this invention provides a method for preparing zinc ion adsorbents from alkaline thermally modified lithium mica slag. The technical solution is as follows:
[0006] A method for preparing zinc ion adsorbent from alkaline thermally modified lithium mica slag, the method comprising:
[0007] S1. Dry the lepidolite smelting slag;
[0008] S2. Grind and sieve the dried lepidolite smelting slag from S1 to obtain the original lepidolite slag.
[0009] S3. The original lithium mica residue obtained in S2 is mixed with NaOH solution and transferred to a micro reactor with a polytetrafluoroethylene liner for hydrothermal modification.
[0010] S4. The hydrothermally modified product in S3 is washed to neutral using a circulating water vacuum filter pump, filtered, dried, and ground to obtain an alkaline hydrothermally modified lithium mica slag adsorbent.
[0011] The material in S1 is dried at 60-80℃ for 8-12 hours. The drying is carried out in an electrically heated forced-air drying oven.
[0012] The lithium mica smelting slag in S2 is ground to a particle size ≤150µm.
[0013] The concentration of NaOH solution in S3 is 0.5~1.5 mol / L, and the solid-liquid ratio of the original lepidolite slag to the NaOH solution is 35~45 g / L.
[0014] The hydrothermal modification conditions in S3 are: temperature 100~150℃, pressure 0.1-0.4MPa, reactor rotation speed 300 r / min, and hydrothermal reaction time 2~6 h.
[0015] The S4 particles are dried at 60-80℃ for 8-12 hours and then ground to a particle size ≤150µm. The drying is carried out in an electrically heated forced-air drying oven.
[0016] The adsorbent application process is as follows:
[0017] The adsorbent obtained in step S4 is added to the zinc ion-containing wastewater and placed in a water bath constant temperature shaker for adsorption. The adsorbed solution is then filtered to obtain purified wastewater.
[0018] The zinc ion concentration in the zinc-containing wastewater is 30-80 mg / L, and the solid-liquid ratio of the adsorbent to the zinc-containing wastewater is 5-8 g / L.
[0019] During the adsorption process, the temperature of the water bath constant temperature oscillator is 20~30℃, the rotation speed is 300 r / min, and the adsorption time is 120~480 min.
[0020] The purified wastewater was measured by inductively coupled plasma atomic emission spectrometry, and the zinc ion adsorption rate was 86.9%~99.9%. Under optimal conditions, the zinc ion content in the purified wastewater could be less than 0.05 mg / L, which is far below the limit of the "Emission Standard for Lead and Zinc Pollutants GB 25466-2010".
[0021] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:
[0022] In the above scheme, alkaline thermal modification can alter the surface properties and pore structure of the material through temperature and alkaline environment regulation, promoting lattice reconstruction and active site generation, thereby improving adsorption performance. The adsorption material used in this invention is inexpensive, simple to operate, and has good adsorption effect. Alkaline thermal modification of lepidolite slag not only adsorbs zinc ions from water but also solves the environmental pollution problem caused by the stockpiling of lepidolite smelting slag. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 These are FTIR spectra of lithium mica slag before and after alkaline water thermal modification and before and after adsorption of Zn(II) in different alkalinities in the embodiments of the present invention. Detailed Implementation
[0025] The technical solutions of the present invention will now be described with reference to the accompanying drawings and embodiments.
[0026] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.
[0027] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with specific embodiments.
[0028] This invention provides a method for preparing zinc ion adsorbents from alkaline hydrothermal modification of lithium mica slag. The method may include the following steps:
[0029] S1. Dry the lepidolite smelting slag;
[0030] S2. Grind and sieve the dried lepidolite smelting slag from S1 to obtain the original lepidolite slag.
[0031] S3. The original lithium mica residue obtained in S2 is mixed with NaOH solution and transferred to a micro reactor with a polytetrafluoroethylene liner for hydrothermal modification.
[0032] S4. The hydrothermally modified product in S3 is washed to neutral using a circulating water vacuum filter pump, filtered, dried, and ground to obtain an alkaline hydrothermally modified lithium mica slag adsorbent.
[0033] The adsorbent application process is as follows:
[0034] The adsorbent obtained in step S4 is added to the zinc ion-containing wastewater and placed in a water bath constant temperature shaker for adsorption. The adsorbed solution is then filtered to obtain purified wastewater.
[0035] The following description, in conjunction with specific embodiments, illustrates this point.
[0036] Example 1
[0037] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 150℃, hydrothermal time 4 h, NaOH solution concentration 1.5 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0038] The adsorbent was added to a zinc ion solution with an initial concentration of 50 mg / L at a dosage of 7 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0039] The results showed that the adsorption rate of zinc ions by alkaline water-heat modified lithium mica slag was 96.75%.
[0040] Example 2
[0041] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 150℃, hydrothermal time 4 h, NaOH solution concentration 1.5 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0042] The adsorbent was added to a zinc ion solution with an initial concentration of 50 mg / L at a dosage of 8 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0043] The results showed that the adsorption rate of zinc ions by alkaline water-heat modified lithium mica slag was 97.78%.
[0044] Example 3
[0045] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 150℃, hydrothermal time 4 h, NaOH solution concentration 1.5 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0046] The adsorbent was added to a zinc ion solution with an initial concentration of 30 mg / L at a dosage of 7 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0047] The results showed that the adsorption rate of zinc ions by alkaline water-heat modified lithium mica slag was 99.84%.
[0048] Example 4
[0049] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 150℃, hydrothermal time 4 h, NaOH solution concentration 1.5 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0050] The adsorbent was added to a zinc ion solution with an initial concentration of 40 mg / L at a dosage of 7 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0051] The results showed that the adsorption rate of zinc ions by alkaline water-heat modified lithium mica slag was 99.09%.
[0052] Comparative Example 1
[0053] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 150℃, hydrothermal time 4 h, NaOH solution concentration 1 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0054] The adsorbent was added to a zinc ion solution with an initial concentration of 50 mg / L at a dosage of 3 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0055] The results showed that the adsorption rate of zinc ions on alkaline hydrothermal modified lepidolite slag increased from 9.74% for the unmodified lepidolite slag under the same adsorption conditions to 65.51%.
[0056] Comparative Example 2
[0057] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 125℃, hydrothermal time 6 h, NaOH solution concentration 1.5 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0058] The adsorbent was added to a zinc ion solution with an initial concentration of 50 mg / L at a dosage of 4 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0059] The results showed that the adsorption rate of zinc ions by alkaline water-heat modified lithium mica slag was 77.64%.
[0060] Comparative Example 3
[0061] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 100℃, hydrothermal time 2 h, NaOH solution concentration 0.5 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0062] The adsorbent was added to a zinc ion solution with an initial concentration of 50 mg / L at a dosage of 4 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0063] The results showed that the adsorption rate of zinc ions by alkaline water-heat modified lithium mica slag was 47.37%.
[0064] Comparative Example 4
[0065] Alkali-modified lepidolite slag adsorbent was prepared under the following hydrothermal conditions: temperature 150℃, hydrothermal time 0.5 h, NaOH solution concentration 2 mol / L, and solid-liquid ratio of original lepidolite slag to NaOH solution 40 g / L.
[0066] The adsorbent was added to a zinc ion solution with an initial concentration of 50 mg / L at a dosage of 3 g / L. The solution was adsorbed for 300 min in a water bath constant temperature shaker at a temperature of 25℃ and a rotation speed of 300 r / min. The solution was then filtered, and the residual zinc ion content in the solution was measured using an inductively coupled plasma atomic emission spectrometer.
[0067] The results showed that the adsorption rate of zinc ions by alkaline water-heat modified lithium mica slag was 64.4%.
[0068] Combination Figure 1 As the concentration of modified alkali increases, the modified lithium mica slag at 3463 cm⁻¹... -1 -OH and 1000 cm -1The peak intensity of Si-OT (T represents Si and Al) also increased accordingly, while the two peaks weakened significantly after zinc ion adsorption, indicating that the number of active hydroxyl groups on the surface of the lepidolite slag increased and the silicon-aluminum framework structure changed after alkaline hydrothermal modification. Example 1 shows that the alkaline hydrothermal modified lepidolite slag achieved a zinc ion adsorption rate as high as 96.75% at an alkaline alkali concentration of 1.5 mol / L. The comparison of the spectra before and after adsorption shows that the adsorption mechanism of Zn(II) by the modified lepidolite slag mainly includes the complexation of surface hydroxyl groups and the ion exchange of the silicon-aluminum framework.
[0069] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for preparing zinc ion adsorbent from alkaline hydrothermal modified lithium mica slag, characterized in that, The method includes: S1. Dry the lepidolite smelting slag; S2. Grind and sieve the dried lepidolite smelting slag from S1 to obtain the original lepidolite slag. S3. The original lithium mica residue obtained in S2 is mixed with NaOH solution and transferred to a micro reactor with a polytetrafluoroethylene liner for hydrothermal modification. S4. The hydrothermally modified product in S3 is washed to neutral using a circulating water vacuum filter pump, filtered, dried, and ground to obtain an alkaline hydrothermally modified lithium mica slag adsorbent.
2. The method for preparing zinc ion adsorbent from alkaline water thermally modified lithium mica slag according to claim 1, characterized in that, The S1 is dried at 60~80℃ for 8~12 h.
3. The method for preparing zinc ion adsorbent from alkaline water thermally modified lithium mica slag according to claim 1, characterized in that, The lithium mica smelting slag in S2 is ground to a particle size ≤150µm.
4. The method for preparing zinc ion adsorbent by alkaline water thermal modification of lithium mica slag according to claim 1, characterized in that, The concentration of NaOH solution in S3 is 0.5~1.5 mol / L, and the solid-liquid ratio of the original lepidolite slag to the NaOH solution is 35~45 g / L.
5. The method for preparing zinc ion adsorbent from alkaline hydrothermal modified lithium mica slag according to claim 1, characterized in that, The hydrothermal modification conditions in S3 are: temperature 100~150℃, pressure 0.1-0.4MPa, reactor rotation speed 300 r / min, and hydrothermal reaction time 2~6 h.
6. The method for preparing zinc ion adsorbent from alkaline water thermally modified lithium mica slag according to claim 1, characterized in that, The S4 particles are dried at 60-80℃ for 8-12 hours and then ground to a particle size ≤150µm.
7. The method for preparing zinc ion adsorbent by alkaline hydrothermal modification of lithium mica slag according to claim 1, characterized in that, The adsorbent application process is as follows: The adsorbent obtained in step S4 is added to the zinc ion-containing wastewater and placed in a water bath constant temperature shaker for adsorption. The adsorbed solution is then filtered to obtain purified wastewater.
8. The method for preparing zinc ion adsorbent from alkaline water thermally modified lithium mica slag according to claim 7, characterized in that, The zinc ion concentration in the zinc-containing wastewater is 30-80 mg / L, and the solid-liquid ratio of the adsorbent to the zinc-containing wastewater is 5-8 g / L.
9. The method for preparing zinc ion adsorbent from alkaline hydrothermal modified lithium mica slag according to claim 7, characterized in that, During the adsorption process, the temperature of the water bath constant temperature oscillator is 20~30℃, the rotation speed is 300 r / min, and the adsorption time is 120~480 min.
10. The method for preparing zinc ion adsorbent from alkaline water thermally modified lithium mica slag according to claim 7, characterized in that, The purified wastewater was measured by inductively coupled plasma atomic emission spectrometry, and the zinc ion content in the purified wastewater was less than 0.5 mg / L.