Red mud-based calcium-iron hydrotalcite-like material as well as preparation method and application thereof
The red mud-based calcium-iron hydrotalcite materials are prepared by mechanical force chemical synthesis method using red mud and zinc hexahydrate, which solves the problems of high energy consumption and secondary waste of LDHs materials in the prior art, and achieves low-cost and efficient organic dye adsorption effect.
Patent Information
- Application Number
- CN202510228258.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-27
- Publication Date
- 2025-05-13
AI Technical Summary
The prior art has high energy consumption and secondary waste generation problems when synthesising LDHs materials using red mud, and the comprehensive utilization rate of red mud is low, and there is a lack of economically feasible red mud reuse technology.
Red mud and zinc nitrate hexahydrate were used as raw materials to prepare red mud-based calcium-iron hydrotalcite materials through mechanical force chemical synthesis, achieving efficient utilization of alkaline and metal components of red mud on the basis of no secondary waste generation.
The method is simple in process, has low energy consumption and low cost, and can effectively prepare red mud-based calcium-iron hydrotalcite materials for adsorbing organic dyes, achieving efficient removal of organic dye wastewater, reaching a removal rate of 85%.
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Figure CN119971991A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of hydrotalcite preparation, and in particular to a method for preparing a red mud-based calcium-iron hydrotalcite material, a red mud-based calcium-iron hydrotalcite material prepared by the preparation method, and application of the red mud-based calcium-iron hydrotalcite material in adsorbing organic dyes. Background Art
[0002] Red mud is the alkaline waste residue discharged from the process of extracting alumina from bauxite. It is red because it contains a large amount of Fe2O3 in its components, so it is called red mud. The production of red mud is closely related to the production of alumina. For every ton of alumina produced, 0.8 to 1.5 tons of red mud will be produced. With the increase in alumina production, the safe storage and sustainable utilization of red mud have attracted more and more attention from countries around the world. Due to the lack of economically feasible red mud utilization technology, the comprehensive utilization rate of red mud has been at a low level, which is a global problem. A large amount of red mud piled up in the open air not only occupies a large amount of land resources, but also pollutes the surrounding soil and water sources. At present, the reuse of red mud in the world is mostly concentrated in: industrial recovery of valuable metals, preparation of flame retardants, cementitious materials, etc. For example, Wei et al. extracted iron from red mud and enriched acid leaching of scandium on the premise of determining the leaching process conditions of temperature, leaching time, solid-liquid ratio and hydrochloric acid concentration for the leaching of scandium in magnetic separation tailings. Qian et al. made a suspension of high-temperature treated red mud and introduced Mg 2+ ions, successfully synthesized Mg / Al / Fe ternary layered double hydroxide by coprecipitation method and added it to ethylene vinyl acetate, successfully improving the flame retardancy of ethylene vinyl acetate composite materials. However, the reuse of these red muds is often accompanied by a large amount of energy loss and other waste generation, which is not the optimal solution for the reuse of red mud.
[0003] At present, there have been a lot of reports on the use of red mud as raw material to prepare LDHs materials for the remediation and treatment of environmental problems. For example, Belviso et al. obtained a zeolite layered double hydroxide composite material (LTA-LDH) by ultrasonic treatment in a mixture of sodium hydroxide and red mud, and adsorbed the active dye RO16. Chai et al. first used acid leaching to obtain an acid leaching solution containing iron and aluminum elements from red mud, and then added magnesium chloride hexahydrate to the acid leaching solution to prepare Mg-Fe-Al layered double hydroxide for the remediation of Pb, Cd and Cu contaminated soil. Ma Zihan et al. proposed a solid waste-based LDH photocatalytic repair material and a preparation method thereof. The method first adds hydrochloric acid to a mixture of titanium slag and red mud, and adds scrap iron under aeration conditions to obtain a first reaction material; the first reaction material is heated and alcoholized to separate the solid and liquid to obtain a filter residue, and the dry residue is obtained after drying; the dry residue, filtrate and waste concrete fine powder are mixed and the pH of the solution is adjusted to 9-11 to obtain a second reaction material; the second reaction material is ultrasonically shaken and aged to separate the solid and liquid, and dried to obtain a solid waste-based LDH photocatalytic repair material. However, most of these preparation methods belong to liquid phase synthesis technology, and generally high-temperature calcination or acid leaching with organic acid or inorganic acid is performed as a step in the pretreatment of red mud, and then alkaline sodium hydroxide or other alkaline chemical reagents are added in subsequent steps to provide an alkaline environment required for the construction and preparation of LDHs materials. A large amount of energy or acidic chemical reagents are consumed in these processes. Therefore, in order to achieve the environmentally friendly utilization of red mud, it is very necessary to explore a new method for synthesizing LDHs using red mud as the main raw material, with low energy consumption, reduced addition of various acidic substances, no secondary waste generation during the synthesis process, and efficient utilization of alkaline and metal components in red mud. Summary of the invention
[0004] In view of this, in order to achieve efficient utilization of alkaline and metal components in red mud to synthesize hydrotalcite materials, in the first aspect, the present invention provides a method for preparing a red mud-based calcium-iron hydrotalcite material, using red mud and zinc nitrate hexahydrate as raw materials, and synthesizing it through a simple mechanochemical synthesis method. A new type of red mud-based calcium-iron hydrotalcite material is synthesized on the basis of no secondary waste generation. This material can be used as a low-cost and efficient organic dye adsorbent.
[0005] To achieve the above object, the present invention provides the following technical solutions:
[0006] The invention discloses a method for preparing a red mud-based calcium iron hydrotalcite material. The material is synthesized by a mechanochemical synthesis method using red mud and zinc nitrate hexahydrate as raw materials.
[0007] Preferably, the method specifically comprises the following steps:
[0008] Step (1), placing red mud, zinc nitrate hexahydrate, zirconium oxide balls and deionized water in a ball mill and milling them;
[0009] After the ball milling is completed in step (2), the reaction product is centrifuged, washed, and dried to obtain a precipitate, which is a red mud-based calcium-iron hydrotalcite material.
[0010] Preferably, in step (1), the mass ratio of red mud to zinc nitrate hexahydrate is 1:0.75 to 1:3.
[0011] Preferably, in step (1), the ratio of zirconium oxide to red mud and zinc nitrate hexahydrate is 20:1 to 90:1.
[0012] Preferably, in step (1), the ball milling speed is 150 to 350 rpm.
[0013] Preferably, in step (1), the ball milling is performed for 2-6 hours.
[0014] Preferably, in step (1), the amount of deionized water added is 1 to 6 mL.
[0015] Preferably, the main chemical components of red mud are Fe2O3, Al2O3, SiO2, TiO2 and CaO.
[0016] In a second aspect, the present invention further provides a novel red mud-based calcium-iron hydrotalcite material, which is prepared using the above-mentioned method for preparing the red mud-based calcium-iron hydrotalcite material.
[0017] In a third aspect, the present invention also provides the use of the novel red mud-based calcium iron hydrotalcite material in the adsorption of organic dyes.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] Mechanochemical synthesis is a solid-phase reaction technology based on high-energy ball milling, which is considered to be an efficient and green method for preparing various composite materials. Compared with the traditional liquid phase method, mechanochemical synthesis has the advantages of simple process, low energy consumption, low pollution, low cost and suitability for large-scale production.
[0020] The present invention uses red mud and zinc nitrate hexahydrate as raw materials, synthesizes a new type of red mud-based calcium iron hydrotalcite material through a simple mechanochemical synthesis method without generating secondary waste, and the material can be used as a low-cost and efficient organic dye adsorbent. The details are as follows:
[0021] The method uses red mud, a large industrial solid waste, as the main raw material, effectively utilizes the alkaline components and metal components inherent in red mud, and successfully prepares a new type of red mud-based calcium iron hydrotalcite material with the aid of a simple mechanochemical method. The synthesis process of this method abandons the high energy consumption and secondary waste generation in the method of synthesizing LDHs using red mud. The preparation method is simple and only requires one step of wet grinding to obtain the target product. Compared with the existing two-step ball milling method, the time and steps greatly reduce the investment of related costs, and it is a green and efficient synthesis method. In addition, the red mud-based calcium iron hydrotalcite material synthesized by the mechanochemical method of the present invention can be used as a low-cost and efficient organic dye adsorbent, achieving a removal rate of up to 85% of organic dye wastewater within half an hour. The present invention provides a new solution for the high-value utilization of red mud and the green treatment of dye wastewater, which has the dual significance of environmental protection and resource utilization, and has important application value and broad application prospects for promoting the green and sustainable development of the metallurgical industry. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 The X-ray diffraction pattern of the calcium iron hydrotalcite material prepared under the condition that the mass ratio of red mud to zinc nitrate hexahydrate is 1:2 (g) in Example 1;
[0023] Figure 2 This is a scanning electron micrograph of the calcium iron hydrotalcite material prepared under the condition of a mass ratio of red mud to zinc nitrate hexahydrate of 1:2 (g) in Example 1.
[0024] Figure 3 This is the absorption spectrum of the calcium iron hydrotalcite material prepared under the condition of a mass ratio of red mud to zinc nitrate hexahydrate of 1:2 (g) in Example 1 to sodium indigo disulfonate solution at different times. DETAILED DESCRIPTION
[0025] The technical solution of the present invention is clearly described in detail below in conjunction with specific embodiments.
[0026] Example 1
[0027] The red mud-based calcium iron hydrotalcite material was synthesized by changing the mass ratio of red mud and zinc nitrate hexahydrate.
[0028] Weigh red mud and zinc nitrate hexahydrate in different mass ratios (the mass ratios of red mud and zinc nitrate hexahydrate are 1:3, 1:2, 1:1.5, 1:1, and 1:0.75, respectively), add the corresponding mass of zirconium oxide balls (ensuring that the ball-to-material ratio of zirconium oxide and other reagents (the total mass of red mud and zinc nitrate hexahydrate) is 50:1), and finally add 2 mL of deionized water, and put it into a ball mill at a ball mill speed of 250 rpm for one-step wet grinding for 4 hours.
[0029] After the ball milling is completed, the reaction product is centrifuged and washed, and the precipitate obtained after drying at 60°C for 12 hours is the red mud-based calcium iron hydrotalcite material. Weigh 0.05g of the prepared red mud-based calcium iron hydrotalcite material, put it into 100mL of organic dye wastewater with a pH of 3 and a concentration of 50mg / L of sodium indigo disulfonate, and the organic dye wastewater can be removed within half an hour under magnetic stirring at room temperature under dark conditions. The X-ray diffraction pattern, scanning electron micrograph and absorption spectrum of the sodium indigo disulfonate solution at different times of this embodiment are shown respectively as follows: Figure 1-3 shown.
[0030] Example 2
[0031] The red mud-based calcium iron hydrotalcite material was synthesized by changing the amount of added water.
[0032] Weigh 1g red mud, 2g zinc nitrate hexahydrate and 150g zirconium oxide balls (the ball-to-material ratio of zirconium oxide and other reagents (the total mass of red mud and zinc nitrate hexahydrate) is 50:1) in five portions, add 1, 2, 4, 5, and 6mL of deionized water respectively, and put them into a ball mill with a ball milling speed of 250rpm for one-step wet grinding for 4h. After the ball milling is completed, the reaction product is centrifuged and washed, and the precipitate obtained after drying at 60°C for 12h is the red mud-based calcium iron hydrotalcite material.
[0033] Weigh 0.05 g of the obtained red mud-based calcium iron hydrotalcite material and put it into 100 mL of organic dye wastewater with a pH of 3 and a concentration of 50 mg / L of sodium indigo disulfonate. The organic dye wastewater can be removed under magnetic stirring at room temperature within half an hour under dark conditions.
[0034] Example 3
[0035] The red mud-based calcium iron hydrotalcite material was synthesized by changing the one-step wet grinding time.
[0036] Same as Example 2, except that the time for one-step wet grinding is 2, 3, 4, 5, and 6 h, respectively.
[0037] Weigh 0.05 g of the obtained red mud-based calcium iron hydrotalcite material and put it into 100 mL of organic dye wastewater with a pH of 3 and a concentration of 50 mg / L of sodium indigo disulfonate. The organic dye wastewater can be removed under magnetic stirring at room temperature within half an hour under dark conditions.
[0038] Example 4
[0039] The red mud-based calcium iron hydrotalcite material was synthesized by changing the ball milling speed.
[0040] Same as Example 2, except that the ball milling speeds are 150, 200, 250, 300, and 350 rpm, respectively.
[0041] Weigh 0.05 g of the obtained red mud-based calcium iron hydrotalcite material and put it into 100 mL of organic dye wastewater with a pH of 3 and a concentration of 50 mg / L of sodium indigo disulfonate. The organic dye wastewater can be removed under magnetic stirring at room temperature within half an hour under dark conditions.
[0042] Example 5
[0043] The red mud-based calcium iron hydrotalcite material was synthesized by changing the ball-to-material ratio (the mass ratio of zirconium oxide and other reagents (the total mass of red mud and zinc nitrate hexahydrate)).
[0044] Same as Example 2, except that 60, 90, 150, 210, and 270 g of zirconium oxide balls were added respectively (the ratio of zirconium oxide to other reagents (total mass of red mud and zinc nitrate hexahydrate) was 20:1, 30:1, 50:1, 70:1, and 90:1 (g)).
[0045] Weigh 0.05 g of the obtained red mud-based calcium iron hydrotalcite material and put it into 100 mL of organic dye wastewater with a pH of 3 and a concentration of 50 mg / L of sodium indigo disulfonate. The organic dye wastewater can be removed under magnetic stirring at room temperature within half an hour under dark conditions.
[0046] Example 6
[0047] The amount of red mud-based calcium iron hydrotalcite material added was changed to adsorb the sodium indigo disulfonate organic dye in the wastewater.
[0048] 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06 g of the red mud-based calcium iron hydrotalcite material prepared when the mass ratio of red mud to zinc nitrate hexahydrate in Example 1 was 1:2 were weighed respectively, and put into 100 mL of organic dye wastewater with a pH of 3 and a concentration of 50 mg / L of sodium indigo disulfonate, respectively. The organic dye wastewater can be removed under magnetic stirring at room temperature within half an hour under dark conditions.
[0049] Example 7
[0050] The sodium indigo disulfonate solution was changed to adsorb the sodium indigo disulfonate organic dye in wastewater.
[0051] 0.04 g and five parts of the red mud-based calcium iron hydrotalcite material prepared when the mass ratio of red mud to zinc nitrate hexahydrate in Example 1 is 1:2 were weighed respectively, and put into 100 mL of sodium indigo disulfonate organic dye wastewater with a pH of 3 and a concentration of 10, 30, 50, 70, and 90 mg / L, respectively. The organic dye wastewater can be removed under magnetic stirring at room temperature within half an hour under dark conditions.
[0052] Example 8
[0053] The sodium indigo disulfonate solution was changed to adsorb the sodium indigo disulfonate organic dye in wastewater.
[0054] 0.05 g and five parts of the red mud-based calcium iron hydrotalcite material prepared when the mass ratio of red mud to zinc nitrate hexahydrate in Example 1 is 1:2 were weighed respectively, and put into 100 mL of organic dye wastewater containing sodium indigo disulfonate at a concentration of 50 mg / L at pH = 3, 4, 5, 6, 7, 8, and 9, respectively. The organic dye wastewater can be removed under magnetic stirring at room temperature within half an hour under dark conditions.
Claims
1. A method for preparing a red mud-based calcium iron hydrotalcite material, characterized in that: It is synthesized by mechanochemical synthesis method using red mud and zinc nitrate hexahydrate as raw materials.
2. The method for preparing a red mud-based calcium iron hydrotalcite material according to claim 1, characterized in that: The specific steps include: Step (1), placing red mud, zinc nitrate hexahydrate, zirconium oxide balls and deionized water in a ball mill and milling them; After the ball milling in step (2), the reaction product is centrifuged, washed and dried to obtain a precipitate, which is a red mud-based calcium iron hydrotalcite material.
3. The method for preparing a red mud-based calcium iron hydrotalcite material according to claim 2, characterized in that: In step (1), the mass ratio of red mud to zinc nitrate hexahydrate is 1:0.75 to 1:
3.
4. The method for preparing a red mud-based calcium iron hydrotalcite material according to claim 2, characterized in that: In step (1), the ball-to-material ratio of the mixture of zirconium oxide: red mud and zinc nitrate hexahydrate is 20:1 to 90:
1.
5. The method for preparing a red mud-based calcium iron hydrotalcite material according to claim 2, characterized in that: In step (1), the ball milling speed is 150 to 350 rpm.
6. The method for preparing a red mud-based calcium iron hydrotalcite material according to claim 2, characterized in that: In step (1), the ball milling is performed for 2-6 hours.
7. The method for preparing a red mud-based calcium iron hydrotalcite material according to claim 2, characterized in that: In step (1), the amount of deionized water added is 1 to 6 mL.
8. A method for preparing a red mud-based calcium iron hydrotalcite material according to any one of claims 1 to 7, characterized in that: The main chemical components of red mud are Fe2O3, Al2O3, SiO2, TiO2 and CaO.
9. A novel red mud-based calcium iron hydrotalcite material, characterized in that: The material is prepared by the method for preparing a red mud-based calcium iron hydrotalcite material according to any one of claims 1 to 8.
10. Use of the novel red mud-based calcium iron hydrotalcite material according to claim 9 in adsorbing organic dyes.