An efficient sulfidation method for preparing hematite, and the application of sulfidated hematite materials in the removal of hexavalent molybdenum from water.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-11
- Publication Date
- 2026-08-14
AI Technical Summary
然而，单一硫化试剂在处理效率、硫化程度及材料稳定性方面仍存在一定局限性
[0017]与常用的硫化技术相比，本发明的有益效果在于：本发明利用硫化钠和连二亚硫酸钠协同作用对赤铁矿进行硫化处理，相比于采用单一硫化试剂处理，可对赤铁矿表面实现深层硫化，从而显著提高材料对Mo(VI)的吸附容量。本发明制备方法简单、操作安全简便、环境友好、易于实现工业化生产。由于赤铁矿来源广泛，所采用的硫化试剂用量可控且可以循环使用，能有效降低生产成本，具有良好的经济可行性。
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Abstract
Description
Technical Field
[0001] This invention relates to the preparation technology of hematite sulfide and its application, specifically to an efficient sulfidation preparation method for hematite, hematite sulfide materials, and their application in the removal of hexavalent molybdenum from water. Background Technology
[0002] Molybdenum (Mo), as an important strategic metal, plays a vital role in numerous fields, including energy, chemicals, pharmaceuticals, and aerospace. However, molybdenum mining, smelting, and industrial production processes generate large amounts of molybdenum-containing wastewater. If discharged into the aquatic environment without effective treatment, this wastewater will directly impact the safety of aquatic ecosystems. In the natural environment, molybdenum is primarily found in the form of hexavalent molybdenum (MoO4). 2- It exists in the form of molybdenum, exhibiting high mobility and bioavailability, and easily accumulates in aquatic organisms and the human body. Therefore, the preparation of efficient, economical, and environmentally friendly materials for treating molybdenum in water is of significant practical importance.
[0003] Adsorption methods are widely used for the removal of heavy metals and oxygen-containing anions from water due to their advantages such as simple operation, controllable cost, and high removal rate. Iron-based adsorbents, especially those synthesized using iron oxides (such as hematite and goethite) as a matrix, have received considerable attention in recent years due to their wide availability and good environmental compatibility. However, the adsorption capacity of natural hematite for molybdenum is relatively limited, making it difficult to meet the needs of practical water treatment. Sulfidation modification of iron-based materials can introduce active reducing species such as iron sulfides onto their surface. This phase possesses strong reducing power and surface reactivity, thereby effectively improving the material's removal performance of hexavalent molybdenum from water.
[0004] Sulfidation modification of hematite typically involves direct surface treatment with sodium sulfide. However, single sulfidation agents still have limitations in terms of processing efficiency, degree of sulfidation, and material stability. To address the high crystallinity and low reactivity of hematite, a highly efficient and controllable synergistic sulfidation method is developed to achieve deep sulfidation of the hematite surface, effectively improving the material's molybdenum-coated properties.
[0005] Based on this, this invention innovatively proposes a synergistic approach of sodium sulfide and sodium dithionite to efficiently sulfide hematite, which can significantly enhance the reactivity of the material surface, thereby greatly improving the removal efficiency of hexavalent molybdenum from water by hematite, and has good application prospects.
[0006] Therefore, how to develop an efficient sulfidation preparation method for hematite and the application of sulfidated hematite materials in the removal of hexavalent molybdenum from water are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention
[0007] In view of this, the present invention provides an efficient sulfidation preparation method for hematite, a sulfidated hematite material, and its application in the removal of hexavalent molybdenum from water.
[0008] A highly efficient sulfidation method for preparing hematite includes the following steps:
[0009] (1) Take a certain mass of sodium sulfide and sodium dithionite, and prepare sodium sulfide solution and sodium dithionite solution of a certain concentration respectively with deionized water. (2) A certain mass of hematite is added to a mixture containing sodium sulfide and sodium dithionite solutions in different volume ratios and the volume is adjusted to a certain volume. After ultrasonic dispersion, the mixture is allowed to react fully at a certain temperature for a certain time. After solid-liquid separation, washing, and freeze-drying, hematite sulfide is obtained.
[0010] Furthermore, the concentrations of the sodium sulfide solution and sodium dithionite solution prepared in step (1) are 0.2-2 mol / L, respectively.
[0011] Furthermore, the ratio of sulfur atoms provided by sodium sulfide and sodium dithionite in the mixture in step (2) is (2-8):(2-8), preferably 4:6.
[0012] Furthermore, in step (2), the amount of hematite added is such that the molar ratio of sulfur to iron atoms in the system is (4-10):1, preferably 6:1, and the concentration of hematite in the reaction system is 2-10 g / L.
[0013] Furthermore, the reaction temperature in step (2) is 50-80℃.
[0014] Furthermore, the reaction time in step (2) is 2-12 h, preferably 4 h.
[0015] The present invention also provides a hematite sulfide material prepared by the preparation method described above.
[0016] The present invention also provides an application of the aforementioned hematite sulfide material in the removal of hexavalent molybdenum from water.
[0017] Compared with commonly used sulfidation techniques, the advantages of this invention are as follows: This invention utilizes the synergistic effect of sodium sulfide and sodium dithionite to sulfidate hematite. Compared with treatment using a single sulfidation reagent, it can achieve deep sulfidation of the hematite surface, thereby significantly improving the material's adsorption capacity for Mo(VI). The preparation method of this invention is simple, safe, convenient, environmentally friendly, and easy to implement for industrial production. Since hematite is widely available, the amount of sulfidation reagent used is controllable and can be recycled, effectively reducing production costs and demonstrating good economic feasibility. Detailed Implementation
[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] Example 1 A 1 mol / L sodium sulfide solution and a 1 mol / L sodium dithionite solution were prepared using deionized water. 7.5 mL of the sodium sulfide solution and 5.625 mL of the sodium dithionite solution were accurately measured and mixed to obtain a mixture. 0.25 g of hematite was accurately weighed and added to the mixture, which was then brought to a final volume of 50 mL. The mixture was ultrasonically dispersed at 100 W for 5 min and then reacted at 70 °C with shaking at a rate of 180 rpm for 4 h. After solid-liquid separation, the mixture was washed with deionized water and ethanol, and then freeze-dried at -80 °C for 24 h to obtain hematite sulfide. During the preparation of this material, the ratio of sulfur atoms provided by sodium sulfide to sodium dithionite in the mixture was fixed at 4:6, the sulfur-iron molar ratio was 6:1, and the concentration of hematite in the reaction system was 5 g / L.
[0020] Example 2 Similar to Example 1, except that the mixture contains 15 mL of sodium sulfide solution and 1.875 mL of sodium dithionite solution, so that the ratio of sulfur atoms provided by sodium sulfide and sodium dithionite is 8:2, thus preparing hematite sulfide material.
[0021] Example 3 Similar to Example 1, except that the mixture contains 3.75 mL of sodium sulfide solution and 7.5 mL of sodium dithionite solution, so that the ratio of sulfur atoms provided by sodium sulfide and sodium dithionite is 2:8, thus preparing hematite sulfide material.
[0022] Example 4 Similar to Example 1, except that the mixture contains 5 mL of sodium sulfide solution and 3.75 mL of sodium dithionite solution to maintain a sulfur-iron molar ratio of 4:1, in order to prepare hematite sulfide material.
[0023] Example 5 Similar to Example 1, except that the mixture contains 12.5 mL of sodium sulfide solution and 6.25 mL of sodium dithionite solution to maintain a sulfur-iron molar ratio of 10:1, in order to prepare hematite sulfide material.
[0024] Example 6 Same as Example 1, except that the volume of the constant volume is changed to 125 mL, so that the concentration of hematite in the reaction system is 2 g / L, and sulfide hematite material is prepared.
[0025] Example 7 Same as Example 1, except that the reaction temperature is 80°C.
[0026] Example 8 Same as Example 1, except that the reaction time is 12 h.
[0027] Example 9 50 mg of each of the hematite sulfide materials prepared in Examples 1-8 were weighed and placed in 50 mL of molybdenum-containing solution (initial Mo(VI) concentration was 40 mg / L, pH 7). After shaking and reacting for 24 h, the residual molybdenum concentration in the solution was determined by ICP-MS, and the removal rate was calculated accordingly. The results are shown in Table 1.
[0028] Table 1. Experimental results of different hematite sulfide materials for removing Mo(VI) from water.
[0029] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A highly efficient sulfidation method for preparing hematite, characterized in that, Includes the following steps: (1) Take a certain mass of sodium sulfide and sodium dithionite, and prepare sodium sulfide solution and sodium dithionite solution of a certain concentration respectively with deionized water. (2) A certain mass of hematite is added to a mixture containing sodium sulfide and sodium dithionite solutions in different volume ratios and the volume is adjusted to a certain volume. After ultrasonic dispersion, the mixture is allowed to react fully at a certain temperature for a certain time. After solid-liquid separation, washing, and freeze-drying, hematite sulfide is obtained.
2. The efficient sulfidation preparation method for hematite according to claim 1, characterized in that, The concentrations of the sodium sulfide solution and sodium dithionite solution prepared in step (1) are 0.2-2 mol / L, respectively.
3. The efficient sulfidation preparation method for hematite according to claim 1, characterized in that, In step (2), the ratio of sulfur atoms provided by sodium sulfide and sodium dithionite in the mixture is (2-8):(2-8).
4. The efficient sulfidation preparation method for hematite according to claim 1, characterized in that, The amount of hematite added in step (2) is such that the molar ratio of sulfur to iron atoms in the system is (4-10):1, and the concentration of hematite in the reaction system is 2-10 g / L.
5. The efficient sulfidation preparation method for hematite according to claim 1, characterized in that, The reaction temperature in step (2) is 50-80℃.
6. The efficient sulfidation preparation method for hematite according to claim 1, characterized in that, The reaction time in step (2) is 2-12 h.
7. A hematite sulfide material prepared by the preparation method according to any one of claims 1-6.
8. The application of the hematite sulfide material of claim 7 in the removal of hexavalent molybdenum from water.