Method for preparing sheet-shaped water treatment functional material from vanadium-titanium magnetite tailings fine mud

Abstract

The application discloses a method for preparing a layered water treatment functional material from vanadium-titanium magnetite tailing slime. The method comprises the following steps: adding the vanadium-titanium magnetite tailing slime into a sodium hydroxide solution, and then performing water bath heating; centrifuging and separating, and reserving the supernatant to obtain a sodium silicate solution; adding calcium chloride into the sodium silicate solution, and reacting at room temperature for 1-4 hours; and after the reaction is completed, centrifuging and drying to obtain the layered water treatment functional material. The method uses low-cost vanadium-titanium magnetite tailing slime as a main raw material, and realizes low-cost preparation of a high-performance water treatment functional material by converting the vanadium-titanium magnetite tailing slime into sodium silicate and then preparing a high-dispersion two-dimensional water treatment functional material.

Description

Technical Field

[0001] The technical solution of this invention relates to the field of adsorbent synthesis, specifically a method for preparing layered sheet-like water treatment functional materials from vanadium-titanium magnetite tailings sludge. Background Technology

[0002] With industrial development, large amounts of heavy metal ions are discharged into water, making the removal of heavy metal ions from water using adsorbents an important technology. Calcium silicate hydrate, as a common functional material for water treatment, possesses excellent adsorption properties and is widely used in fields such as heavy metal ion wastewater treatment.

[0003] Calcium silicate hydrate has shown excellent application prospects in the treatment of heavy metal ion wastewater, but its high synthesis cost and spontaneous aggregation characteristics limit its industrial application. Using tailings sludge as a silicon source to prepare high-performance water treatment functional materials (calcium silicate hydrate) can not only effectively reduce synthesis costs but also mitigate the environmental risks associated with tailings storage. Therefore, finding a suitable preparation method for high-performance water treatment functional materials is of great significance.

[0004] CN112661164A discloses a method for preparing hydrated calcium silicate using waste cement-based materials and non-wood pulping black liquor as raw materials. First, the waste cement-based materials are acid-treated, then mixed with filtered non-wood pulping black liquor to undergo a co-precipitation reaction for 2 hours to obtain hydrated calcium silicate. However, the hydrated calcium silicate prepared by this method is granular with small particle size and poor dispersibility. CN114275790A involves a method for preparing hydrated calcium silicate. First, fly ash is leached with an alkaline agent to obtain a silicate leachate. Then, this leachate is added dropwise at a uniform rate of 15 mL / h to 35 mL / h to a calcium hydroxide suspension, stirred, and heated to obtain hydrated calcium silicate gel. The hydrated calcium silicate gel is then mixed with an organic alcohol solvent and subjected to azeotropic distillation, followed by separation, drying, and calcination to expand the pores. However, this method has limitations due to the need to control the dropping rate and perform the pore-expansion process, resulting in a long preparation time. CN108584969A discloses a method for preparing hydrated calcium silicate using industrial steel slag. First, a strong alkali activator is prepared by mixing sodium hydroxide solution with water glass. Then, industrial steel slag is added to the activator solution, stirred, and heated to obtain a suspension. The suspension is centrifuged to remove excess strong alkali activator, and then ultrasonicated to obtain a particulate suspension. This is then mixed with unreacted steel slag particles and centrifuged at low speed to obtain nano-hydrated calcium silicate nanosheets. However, due to the need for excess activator, this method has the limitation of complex operation. The EEisinas team (Ceramics International, 2023, 49(9): 14886-14894) provides a one-step hydrothermal synthesis method for hydrated calcium silicate using commercially available calcium and silica. However, this method is costly, and the hydrated calcium silicate has poor dispersibility, which affects Cu. 2+ The maximum adsorption capacity is only 142 mg / g.

[0005] Tailings are a major type of industrial solid waste generated during the processing of metallic and non-metallic minerals. Currently, my country's accumulated tailings have reached 19.5 billion tons, with a comprehensive tailings utilization rate of only 10%. Accumulated tailings not only occupy valuable storage land but also cause environmental pollution and pose risks of dam failures, landslides, and collapses. Therefore, the comprehensive utilization of tailings has attracted widespread attention. Examples include recovering valuable metallic elements, producing building materials (i.e., concrete, fired bricks, glass ceramics, wall materials, etc.), manufacturing functional ceramics, and using them as soil conditioners and micronutrient fertilizers. Common types of tailings include fluorite tailings, molybdenum tailings, vanadium-titanium magnetite tailings, single magnetite tailings, and gold tailings. Vanadium-titanium magnetite tailings are widely distributed and have large reserves in my country. Generally, vanadium-titanium magnetite tailings are mainly composed of quartz and small amounts of metallic elements, with SiO2 content reaching over 40%. The chemical composition and mineralogical properties of vanadium-titanium magnetite tailings are similar to clay, consisting of silicate with a silica framework formed by [SiO4] tetrahedra. This indicates that vanadium-titanium magnetite tailings have the potential to be used as a sustainable material by adjusting the framework structure. However, due to the difficulty in completely removing numerous impurities, the industrial utilization rate is low, and current research on its application is still limited. Summary of the Invention

[0006] This invention addresses the shortcomings of current technologies by providing a low-cost method for preparing highly dispersible, sheet-like water treatment functional material adsorbents from vanadium-titanium magnetite tailings sludge. The method uses vanadium-titanium magnetite tailings sludge treated with alkali leaching as the silicon source. First, the vanadium-titanium magnetite tailings sludge is mixed with a sodium hydroxide solution and heated in a water bath to react silica with sodium hydroxide to form sodium silicate. The suspension is then centrifuged, and the supernatant is retained. Calcium chloride is then added to the supernatant. After the reaction is complete, a well-dispersed water treatment functional material is obtained. This invention uses low-cost vanadium-titanium magnetite tailings sludge as the main raw material, converting it first into sodium silicate before preparing the highly dispersed two-dimensional water treatment functional material, thus achieving the low-cost preparation of high-performance water treatment functional materials.

[0007] The technical solution adopted by this invention to solve this technical problem is:

[0008] A method for preparing layered sheet-like water treatment functional materials from vanadium-titanium magnetite tailings sludge, the method comprising the following steps:

[0009] (1) Add the fine mud of vanadium-titanium magnetite tailings to sodium hydroxide solution, and then heat it in a water bath to obtain a suspension;

[0010] Among them, 8-20g of vanadium-titanium magnetite tailings fine mud is added to every 100mL of sodium hydroxide solution;

[0011] (2) Centrifuge the suspension obtained in step (1) and retain the supernatant to obtain sodium silicate solution;

[0012] (3) Add calcium chloride to sodium silicate solution and react at room temperature for 1-4 hours. After the reaction is complete, filter, rinse and dry to obtain layered water treatment functional material.

[0013] For each 100 mL of sodium silicate solution, add 0.55–3.3 g of calcium chloride;

[0014] Step (1) The water bath temperature is 60-80℃ and the water bath heating time is 0.5-2h.

[0015] In step (1), the concentration of sodium hydroxide solution is 1-6M.

[0016] The composition and content range of the vanadium-titanium magnetite tailings fine mud include: 40%–70% SiO2, 5%–10% Al2O3, 5%–25% CaO, 10%–30% Fe2O3, 5%–15% MgO and 5%–15% other trace components.

[0017] The particle size range of the vanadium-titanium magnetite tailings fine mud is 0.0065 to 0.075 mm.

[0018] The two-dimensional water treatment functional material prepared by the method is used for adsorbing Cr. 3+ and Ni 2+ One or two of them.

[0019] The method for preparing layered water treatment functional materials from vanadium-titanium magnetite tailings sludge described above involves raw materials, reagents, and equipment other than vanadium-titanium magnetite tailings sludge, all of which are obtained through known means, and the operating process is mastered by those skilled in the art.

[0020] The essential features of this invention are:

[0021] This invention uses an alkaline leaching method to treat fine mud from vanadium-titanium magnetite tailings, and then adds calcium chloride and reacts it at room temperature to obtain a water treatment functional material with good dispersibility.

[0022] The beneficial effects of this invention are:

[0023] (1) Compared with water treatment functional materials (hydrated calcium silicate) prepared using chemical reagents as silicon sources, the use of vanadium-titanium magnetite tailings fine mud as silicon source and the process described in this invention significantly improves the dispersibility of water treatment functional materials (hydrated calcium silicate), making its adsorption performance more excellent.

[0024] (2) Compared with CN112661164A, the water treatment functional material (hydrated calcium silicate) prepared by the present invention is in the form of layers and has better dispersibility.

[0025] (3) Compared with CN107721228A, the production process of the present invention is simple, the preparation time is short, and there is no need to expand the hole or control the dropping rate.

[0026] (4) Compared with CN108584969A, the sample prepared by the present invention does not require an activator, so there is no need to remove excess activator.

[0027] (5) Vanadium-titanium magnetite tailings sludge has the characteristics of low price, large stockpile, and high environmental risk of stockpile area. Using it as the main raw material to prepare high-performance water treatment functional materials is in line with the development concept of "turning waste into treasure". Attached Figure Description

[0028] Figure 1 The image shows a TEM image of the sheet-like water treatment functional material prepared in Example 1.

[0029] Figure 2 The image shows a TEM image of the layered water treatment functional material prepared in Example 2.

[0030] Figure 3 For different prepared samples, the effect of Cr 3+ The adsorption performance diagram.

[0031] Figure 4 For different prepared samples, Ni 2+ The adsorption performance diagram. Detailed Implementation

[0032] The present invention will be described below with specific embodiments, but the scope of protection of the present invention is not limited to these examples.

[0033] The tailings described in this invention are known materials, specifically fine mud (particle size 0.0065–0.075 mm) from vanadium-titanium magnetite tailings in Chengde, Hebei Province, with the main components shown in Table 1. However, it is not limited to this.

[0034] Table 1. Main chemical composition (wt%) of fine mud from vanadium-titanium magnetite tailings

[0035]

[0036] Example 1

[0037] 10g of vanadium-titanium magnetite tailings sludge was weighed and added to 100mL of 3M sodium hydroxide solution. The mixture was then transferred to a water bath and heated at 75℃ with stirring for 2 hours. After heating, it was cooled to room temperature and centrifuged at 5000r / min for 5min. The supernatant was retained to obtain 95mL of sodium silicate solution. 1.1g of calcium chloride was added to this sodium silicate solution, and the mixture was stirred at room temperature for 2 hours. After the reaction, it was filtered, washed, and dried to obtain the water treatment functional material. 0.05g of the obtained water treatment functional material was added to 100mL of Cr... 3+ Chromium nitrate solution with a concentration of 250 mg / L and Ni 2+ A 250 mg / L nickel chloride solution was added and stirred on a magnetic stirrer for 2 hours. After stirring, 10 mL of the solution was taken and placed in a GNST-900 water quality analyzer to measure the Cr content. 3+ and Ni 2+ concentration.

[0038] Figure 1 The image shows a TEM image of the well-dispersed water treatment functional material prepared in Example 1. Its microstructure is layered and uniformly distributed.

[0039] Table 2. Main chemical composition (wt%) of the layered water treatment functional material prepared in Example 1.

[0040]

[0041] Example 2

[0042] The other steps are the same as in Example 1, except that "adding 1.1g of calcium chloride to these sodium silicate solutions" is replaced with "adding 0.55g of calcium chloride to these sodium silicate solutions".

[0043] TEM Figure 2 The TEM image shows the layered water treatment functional material prepared in Example 2. It can be seen that although the layer distribution is worse than in Example 1, the layer distribution is uneven, the growth is irregular, and the framework is relatively loose. Some particles appear on the layers, but the prepared water treatment functional material still clearly exhibits a layered structure. This indicates that appropriately changing the calcium-silicon ratio within the parameter range of the technical solution of this invention will not affect the synthesis of the layered water treatment functional material.

[0044] Comparative Example 1

[0045] The other steps differ from those in Example 1 in that "heating and stirring in a water bath at 75°C for 2 hours" is replaced with "heating and stirring in a water bath at room temperature for 2 hours".

[0046] In Comparative Example 1, the product obtained was calcium hydroxide, indicating that the lower reaction temperature could not cause the silica and sodium hydroxide in the tailings sludge to react, resulting in a large amount of sodium hydroxide remaining to react with calcium chloride.

[0047] Comparative Example 2

[0048] The other steps differ from those in Example 1 in that "weighing 10g of vanadium-titanium magnetite tailings fine mud and adding it to 100mL of 3M sodium hydroxide solution" is replaced with "weighing 10g of vanadium-titanium magnetite tailings fine mud and adding it to 100mL of 0.5M sodium hydroxide solution".

[0049] In Comparative Example 2, no obvious product was generated, indicating that a low concentration of sodium hydroxide cannot cause silica and sodium hydroxide in the tailings sludge to react.

[0050] Figure 3 and Figure 4 The graphs show the adsorption performance of Examples 1, 2, Comparative Example 1, and Comparative Example 2, where Example 1 shows the adsorption performance of Cr. 3+ and Ni 2+ The adsorption capacities were 402.52 mg / g and 486.43 mg / g, respectively. Example 2 showed adsorption capacities for Cr... 3+ and Ni 2+ The adsorption capacities were 350.36 mg / g and 470.34 mg / g, respectively. Comparative Example 1 showed adsorption capacities of 350.36 mg / g and 470.34 mg / g for Cr. 3+ and Ni 2+ The adsorption capacities were 124.23 mg / g and 134.56 mg / g, respectively. Comparative Example 2 showed adsorption capacities of 124.23 mg / g and 134.56 mg / g for Cr. 3+ and Ni 2+ The adsorption capacities were 0 mg / g and 0 mg / g, respectively. It is evident that Examples 1 and 2 exhibited better performance than the other samples.

[0051] This invention uses a co-precipitation method to prepare materials with good dispersibility and a large specific surface area, providing a large number of attachment sites for the adsorption of heavy metal ions and allowing a certain amount of calcium ions to exchange with heavy metal ions.

[0052] As can be seen from the above examples and comparative examples, this invention, based on the alkaline leaching treatment of vanadium-titanium magnetite tailings sludge, uses a simple co-precipitation method to prepare layered water treatment functional materials and improves their dispersibility. The preparation process of this invention is simple, uses abundant tailings as a silicon source, is inexpensive, and can serve as a high-quality heavy metal ion adsorbent.

[0053] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

[0054] Matters not covered in this invention are common knowledge.

Claims

1. The application of a layered water treatment functional material prepared from vanadium-titanium magnetite tailings fine sludge, characterized in that, The layered water treatment functional material is used to adsorb Cr. 3+ and Ni 2+ One or two of them; The preparation method of the layered water treatment functional material includes the following steps: (1) Add the fine mud of vanadium-titanium magnetite tailings to a sodium hydroxide solution and then heat it in a water bath to obtain a suspension; Among them, 8–20 g of vanadium-titanium magnetite tailings fine mud is added to every 100 mL of sodium hydroxide solution; (2) Centrifuge the suspension obtained in step (1) and retain the supernatant to obtain sodium silicate solution; (3) Add calcium chloride to sodium silicate solution and react at room temperature for 1-4 h. After the reaction is complete, filter, wash and dry to obtain layered water treatment functional material. For each 100 mL sodium silicate solution, add 0.55–3.3 g of calcium chloride; In step (1), the concentration of the sodium hydroxide solution is 1–6 M; The composition and mass content range of the vanadium-titanium magnetite tailings fine mud include: 40% to 70% SiO2, 5% to 10% Al2O3, 5% to 25% CaO, 10% to 30% Fe2O3, 5% to 15% MgO and 5% to 15% other trace components. The particle size range of the vanadium-titanium magnetite tailings fine mud is 0.0065–0.075 mm; Step (1) The water bath heating temperature is 60-80℃ and the water bath heating time is 0.5-2 h.

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