Method for preparing zeolite by taking scrapped chemical milling liquid as raw material
By combining the waste milling liquid with Jiangxi red soil through hydrothermal reaction method, zeolite with excellent adsorption performance was prepared, which solved the problem of difficult treatment of waste milling liquid during aviation processing, and achieved resource utilization and environmentally friendly water treatment effects.
Patent Information
- Application Number
- CN202510504148.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-05-23
AI Technical Summary
The scrapped milling liquid during aviation processing is difficult to deal with, resulting in waste of chemical raw materials and environmental pollution.
Using the hydrothermal reaction method, the alkali and aluminum active ingredients in the scrapped milling liquid were used, and combined with Jiangxi red soil as the silicon source, zeolites with excellent adsorption performance were prepared.
The resource utilization of scrapped milling liquid is realized, and the prepared zeolite has excellent adsorption performance on rare earth ions and can be recycled and recycled, reducing treatment costs and environmental pollution.
Smart Images
Figure CN120024908A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for preparing zeolite by taking waste milling fluid as raw material, and specifically belongs to the technical field of zeolite preparation. Background Art
[0002] Milling is an important aluminum alloy processing method widely used in the aerospace industry. During the aluminum alloy milling process, aluminum dissolves in the strong alkaline milling fluid and exists in the form of sodium aluminate. As the milling proceeds, sodium aluminate accumulates until the milling fluid fails. When the aluminum ion mass concentration reaches 70~80g / L, the milling fluid will not meet the production requirements and will be scrapped, resulting in a large amount of chemical raw materials being wasted, and the end-of-pipe treatment cost is high, which brings cost and environmental pressure to the company. The scrapped milling fluid still contains a large amount of sodium hydroxide, which will quickly change the pH value of water and soil after entering the environment, making it alkaline, which brings great harm to life in the environment.
[0003] At present, most of the domestic methods for scrapping milling fluids are to reduce the content of dissolved aluminum in them to achieve the reuse of the milling fluids. For example, aluminum hydroxide crystals are added to the milling fluids to induce the dissolved aluminum to precipitate in the form of aluminum hydroxide, thereby reducing the concentration of aluminum ions and achieving the reuse of the scrapped milling fluids. However, this takes a long time and is not efficient. Some milling fluids are used to prepare γ-AlOOH, but cetyltrimethylammonium bromide (CTAB) needs to be added during the preparation process, but this substance is highly toxic.
[0004] Zeolite is a natural ore or synthetic material with a porous structure, and its main component is silicate. Its porous structure gives it a large specific surface area and pore volume, providing abundant adsorption sites. Heavy metal ions exist in aqueous solution in the form of cations and bind to the pores and surface potential of zeolite. This combination can be carried out through ion exchange, coordination bonds and electrostatic effects. Among them, the ion exchange capacity of zeolite is one of the key mechanisms for the adsorption of heavy metals.
[0005] The cations (such as sodium ions) in the zeolite framework can be exchanged with heavy metal ions in the solution. In addition, the surface of zeolite also has some special chemical sites, such as hydroxyl (-OH) and silicon oxygen bond (Si-O-Si). These chemical sites can combine with heavy metal ions through coordination bonds or electrostatic effects to achieve adsorption. Through the above adsorption mechanism, zeolite can effectively remove heavy metal ions in water, such as copper, lead, cadmium, chromium, etc. It has strong ion exchange capacity and adsorption performance, and is rich in content, low in price, easy to obtain, and harmless to the environment.
[0006] Jiangxi is one of the provinces with the largest red soil distribution area, accounting for 70.7% of the province's soil. Red soil is mainly distributed in the mountains, hills and plains of Jiangxi, with mountains and hills being the main areas. Jiangxi red soil is rich in iron compounds and silicon-aluminum compounds, such as limonite and hematite, with a higher content of hematite. These iron-aluminum oxides give the red soil its unique red color.
[0007] Natural zeolite has low adsorption efficiency for heavy metals due to its low purity, poor crystallinity, insufficient adsorption sites, mismatched pore structure characteristics, etc., so it is necessary to artificially synthesize high-purity zeolite, but the cost of artificially synthesized zeolite is expensive and difficult to apply in practice. In view of the current situation that scrapped milling fluid is seriously harmful and difficult to handle, the present invention uses scrapped milling fluid to synthesize zeolite and use it to remove heavy metals in wastewater, which can not only greatly reduce the cost of treatment, but also achieve "waste treatment with waste" and realize efficient utilization of waste resources. Summary of the invention
[0008] In view of the current situation that waste milling fluid in the above-mentioned aviation machining process is difficult to handle, the present invention proposes a method for preparing zeolite using waste milling fluid as raw material.
[0009] The method for preparing zeolite by using waste milling fluid as raw material of the present invention uses Jiangxi red soil as silicon source, utilizes alkali and aluminum effective components in waste milling fluid, prepares zeolite by hydrothermal reaction, and realizes the purpose of resource utilization of waste milling fluid; the specific steps are as follows: Step 1: sieve Jiangxi red soil with a 40-mesh sieve, then dry it at 30°C for 12 hours, and then ball-mill and sieve it with a 100-mesh sieve to obtain red soil with a mesh size less than 100; Step 2: Take 5g of red soil with a mesh size less than 100 and add 52ml of 3 mol / L hydrochloric acid solution. Mix well and activate at 150℃ for 24h. Step 3: The product of step 2 was separated by filtration, and the obtained filter residue was mixed with 58 mL of 3 mol / L NaOH solution, and hydrothermally reacted at 150°C for 12 h. The reaction product was filtered to obtain solution A; Step 4: Add excess NaOH solution until the Al in solution A 3+ All converted to AlO 2- After filtering, the Fe element in the red mud is removed to obtain solution B; Step 5: Take 2 ml of scrap milling liquid, 8.862 g of sodium silicate nonahydrate, and 10.5 ml of 3 mol / L sodium hydroxide and mix them evenly with solution B.
[0010] Step 6: hydrothermally react at 120° C. for 12 h, centrifuge the product, add the obtained filter cake into deionized water, stir for 15 min, centrifuge again, repeat washing with deionized water and centrifugation 3 to 4 times to obtain a washed filter cake; Step 7: The filter cake washed in step 6 is placed in 0.1 M HCl and stirred for 15 minutes, followed by centrifugation, and the obtained filtered product is washed with deionized water until the pH value of the filtrate reaches neutral; Step 8: The filtered product with neutral acidity and alkalinity in step 7 is dried at 70°C for 12 hours, and then ground and passed through a 100-mesh sieve to obtain zeolite.
[0011] The molar ratio of silicon to aluminum in the mixed solution is 1.5, and the molar ratio of sodium hydroxide to silicon to aluminum is 3.
[0012] Beneficial effects of the present invention: The method for preparing zeolite of the present invention is simple in steps, low in energy and cost consumption, and the prepared zeolite has excellent adsorption performance for rare earth ions, especially for La 3+ The isothermal adsorption experiment at different pH values reached 461.144 ppm mg / L, and it can be recycled and reused with good repeatability and stability. 3+ It is a water treatment adsorbent with great application prospects, which realizes the resource utilization of scrap milling fluid. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 : Scanning electron microscope image of the zeolite synthesized by the present invention; Figure 2 : XRD pattern of zeolite synthesized by the present invention; Figure 3 : EDS image of the zeolite synthesized by the present invention; Figure 4 : Adsorption diagram of La by the zeolite synthesized in the present invention at different pH values. DETAILED DESCRIPTION
[0015] Example 1 Synthesis of zeolite from chemical milling wastewater and red soil Step 1: sieve Jiangxi red soil with a 40-mesh sieve, then dry it at 30°C for 12 hours, and then ball-mill and sieve it with a 100-mesh sieve to obtain red soil with a mesh size less than 100; Step 2: Take 5g of red soil with a mesh size less than 100 and add 52ml of 3 mol / L hydrochloric acid solution. Mix well and activate at 150℃ for 24h. Step 3: The product of step 2 was separated by filtration, and the obtained filter residue was mixed with 58 mL of 3 mol / L NaOH solution, and hydrothermally reacted at 150°C for 12 h. The reaction product was filtered to obtain solution A; Step 4: Add excess NaOH solution until the Al in solution A 3+ All converted to AlO 2- After filtering, the Fe element in the red mud is removed to obtain solution B; Step 5: Take 2 ml of scrap milling liquid, 8.862 g of sodium silicate nonahydrate, and 10.5 ml of 3 mol / L sodium hydroxide and mix them evenly with solution B.
[0016] Step 6: hydrothermally react at 120° C. for 12 h, centrifuge the product, add the obtained filter cake into deionized water, stir for 15 min, centrifuge again, repeat washing with deionized water and centrifugation 3 to 4 times to obtain a washed filter cake; Step 7: The filter cake washed in step 6 is placed in 0.1 M HCl and stirred for 15 minutes, followed by centrifugation, and the obtained filtered product is washed with deionized water until the pH value of the filtrate reaches neutral; Step 8: The filtered product with neutral acidity and alkalinity in step 7 is dried at 70°C for 12 hours, and then ground and passed through a 100-mesh sieve to obtain zeolite.
[0017] Isothermal adsorption test of trivalent lanthanum ions on zeolite at different pH values The isothermal adsorption performance of the zeolite prepared by the above steps was studied by adsorbing a series of trivalent lanthanum ions at different pH values at the same temperature.
[0018] The specific process is as follows: The initial concentration is 500 mg / L -1 Solution of trivalent lanthanum ions.
[0019] Prepare 7 conical flasks with pH values of 3, 4, 5, 6, 7, 8 and 9, corresponding to 20 ml of the above trivalent lanthanum ion solution, and then add 20 mg of the zeolite obtained in step 8 to each conical flask.
[0020] The conical flask was placed in a constant temperature shaking box at a temperature of 25°C and a speed of 180 rpm min -1 The mixture was shaken continuously for 24 hours under the condition of 40 °C. After the adsorption was completed, the concentration of trivalent lanthanum ions in the solutions with different pH values was measured by inductively coupled plasma spectrometer.
Claims
1. A method for preparing zeolite using waste milling fluid as raw material, characterized in that: The method uses Jiangxi red soil as a silicon source, utilizes the alkali and aluminum effective components in the waste milling fluid, and prepares zeolite through hydrothermal reaction, thereby achieving the purpose of resource utilization of the waste milling fluid; the specific steps are as follows: Step 1: sieve Jiangxi red soil with a 40-mesh sieve, then dry it at 30°C for 12 hours, and then ball-mill and sieve it with a 100-mesh sieve to obtain red soil with a mesh size less than 100; Step 2: Take 5g of red soil with a mesh size less than 100 and add 52ml of 3 mol / L hydrochloric acid solution. Mix well and activate at 150℃ for 24h. Step 3: The product of step 2 was separated by filtration, and the obtained filter residue was mixed with 58 mL of 3 mol / L NaOH solution, and hydrothermally reacted at 150°C for 12 h. The reaction product was filtered to obtain solution A; Step 4: Add excess NaOH solution until the Al in solution A 3+ All converted to AlO 2- After filtering, the Fe element in the red mud is removed to obtain solution B; Step 5: Take 2 ml of waste milling liquid, 8.862 g of sodium silicate nonahydrate, and 10.5 ml of 3 mol / L sodium hydroxide and mix them evenly with solution B; Step 6: hydrothermally react at 120° C. for 12 h, centrifuge the product, add the obtained filter cake into deionized water, stir for 15 min, centrifuge again, repeat washing with deionized water and centrifugation 3 to 4 times to obtain a washed filter cake; Step 7: The filter cake washed in step 6 is placed in 0.1 M HCl and stirred for 15 minutes, followed by centrifugation, and the obtained filtered product is washed with deionized water until the pH value of the filtrate reaches neutral; Step 8: The filtered product with neutral acidity and alkalinity in step 7 is dried at 70°C for 12 hours, and then ground and passed through a 100-mesh sieve to obtain zeolite.
2. The method for preparing zeolite using waste milling fluid as raw material according to claim 1, characterized in that: The molar ratio of silicon to aluminum in the mixed solution is 1.5, and the molar ratio of sodium hydroxide to silicon to aluminum is 3.