Process for the preparation of a chromium-containing polygeomer material and its use in the steelmaking process

Abstract

The application discloses a preparation method of a chromium-containing geopolymer material and application of the chromium-containing geopolymer material in a steelmaking process, and belongs to the field of geopolymer materials. The preparation of the chromium-containing geopolymer material mainly utilizes an adsorption method and a direct incorporation method to add chromium ions into the geopolymer material. The chromium-containing geopolymer material has wide raw material sources, simple preparation process and low production cost. The chromium-containing geopolymer material, a reducing agent and slag-making material are added before molten steel enters refining, the chromium element in the chromium-containing geopolymer material is reduced into metallic chromium into molten steel by the reducing agent in the process of a steelmaking converter, complete or partial replacement of ferrochrome is realized, and the smelting cost of the chromium-containing steel is reduced. Meanwhile, the application can also realize large-scale treatment of chromium-containing wastewater, is an adsorbent with excellent performance, realizes high added value utilization of solid waste resources, and greatly reduces environmental pollution caused by ferrochrome, and the chromium-containing geopolymer material prepared by the method has great advantages and application prospects in the steelmaking process.

Description

Technical Field

[0001] This invention belongs to the field of geopolymer materials technology, specifically relating to a method for preparing chromium-containing geopolymer materials and their application in the steelmaking process. Background Technology

[0002] The leather, electroplating, nuclear power, and textile industries generate large amounts of chromium-containing wastewater during production processes. Currently, domestic methods for treating chromium-containing wastewater include chemical precipitation, liquid-liquid extraction, ion exchange, electrocoagulation, membrane separation, and adsorption. Among these methods, adsorption is considered a highly efficient and cost-effective way to remove chromium from aqueous solutions. Furthermore, chromium is a crucial alloying element in many alloy steels. The smelting of chromium-containing alloy steel involves adding ferrochrome alloys during the steelmaking process to increase its chromium content. Given my country's large production volume and significant demand for chromium in alloy steel, directly alloying with inexpensive chromium-containing materials during steelmaking can significantly reduce alloying costs.

[0003] Geopolymers are aluminosilicate gel materials composed of a three-dimensional gel network structure of SiO4 and AlO4 tetrahedra. Due to their excellent mechanical properties, high temperature resistance, acid resistance, high specific surface area, and high porosity, they have attracted widespread attention in the field of adsorption catalysis. Furthermore, geopolymers are widely available, mainly from solid wastes such as slag, metakaolin, fly ash, red mud, and electrolytic manganese slag. Therefore, this invention utilizes geopolymer technology to prepare chromium-containing materials required for addition during steelmaking. These chromium-containing materials are mainly prepared through adsorption and direct incorporation methods. Compared with existing preparation methods, this process is simple, involves one-step molding, is environmentally friendly, and has low cost, making it promising for large-scale application in steelmaking. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing chromium-containing geopolymer materials and a method for adding chromium-containing geopolymer materials during the steelmaking process. In the steelmaking converter process, the chromium element in the chromium-containing geopolymer material is reduced to metallic chromium by the reducing agent and enters the molten steel, so as to completely or partially replace ferrochrome alloy and greatly reduce the smelting cost of chromium-containing steel.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing chromium-containing geopolymer materials, wherein the preparation of chromium-containing geopolymer materials mainly utilizes adsorption and direct incorporation methods to add chromium ions to the geopolymer materials.

[0007] (1) The steps for preparing chromium-containing geopolymer materials by adsorption method are as follows:

[0008] S1. Mix the raw materials with a certain activity, the activator and water in a certain proportion with a glass rod to disperse them evenly into a slurry.

[0009] S2. After the slurry is completely reacted in the disperser, it is poured into hot dimethyl silicone oil that is dispersed at high speed. Under the shear force of the disperser, it is dispersed into spheres, cured, vacuum filtered, washed and dried; or after the slurry is completely reacted in the disperser, it is poured into a mold, vibrated up and down to eliminate air bubbles, cured, molded, demolded and crushed and sieved to obtain geopolymer materials of different particle sizes.

[0010] S3. After adsorbing the above-mentioned geopolymer material into chromium-containing wastewater of a certain concentration, solid-liquid separation can be performed to obtain the chromium-containing geopolymer material; the chromium-containing wastewater is wastewater generated during the production processes of leather, electroplating, nuclear power and textile industries.

[0011] (2) The steps for preparing chromium-containing geopolymer materials by direct incorporation method are as follows:

[0012] S1. Mix raw materials with a certain activity, activator, chromium-containing compound and water in a certain proportion with a glass rod to form a chromium-containing slurry.

[0013] S2. After the chromium-containing slurry is completely reacted in a disperser, it is poured into hot dimethyl silicone oil that is dispersed at high speed. Under the shear force of the disperser, it is dispersed into spheres, cured, vacuum filtered, washed and dried; or after the chromium-containing slurry is completely reacted in a disperser, it is poured into a mold, vibrated up and down to eliminate air bubbles, cured, molded, demolded and crushed and sieved to obtain chromium-containing geopolymer materials of different particle sizes.

[0014] Preferably, the active raw material in step S1 of (1) and (2) is a solid waste raw material with certain activity, including one or more of blast furnace granulated slag, metakaolin, red mud, steel slag, electrolytic manganese slag, fly ash, silica fume, and rice husk ash.

[0015] Preferably, the activator in steps (1) and (2) S1 includes various acidic activators and various basic activators. The acidic activator is one or more of hydrochloric acid, phosphoric acid, nitric acid, and sulfuric acid. The basic activator is one or more of sodium hydroxide / potassium hydroxide solution, sodium / potassium dry powder water glass, and sodium / potassium liquid water glass.

[0016] Preferably, in step S1 of (1), the mass ratio of the active raw material, activator and water is 2-10: 5-10: 0-4.

[0017] Preferably, the chromium-containing compound in step S1 of (2) includes one or more of chromium nitrate nonahydrate, chromium chloride, and chromium sulfate; the mass ratio of the active raw material, activator, chromium-containing compound, and water is 2-10:5-10:1-4:0-4.

[0018] Preferably, in step S2 of (1) and (2), the dispersion speed of the slurry / chromium-containing slurry after mixing in the disperser is 100-4500 rpm, the dispersion time is 1-20 min, the hot dimethyl silicone oil and the curing temperature are both 20-200℃, and the stirring speed of the high-speed dispersed hot dimethyl silicone oil is 100-3000 rpm.

[0019] Preferably, in step S2 of (1) and (2), the up-and-down vibration time is 1 min-50 min, the curing temperature is 20-200℃, and the curing time is 2 min-96 h; the chromium-containing geopolymer materials of different particle sizes include one or more of powder, granules or small block materials, with a size of 1-500 μm.

[0020] Preferably, in step S3 of (1), the chromium concentration of the chromium-containing wastewater is 0.01 ppm to saturated solutions at different temperatures, and the adsorption time is 0.01 min to 48 h.

[0021] The present invention also provides the application of the chromium-containing geopolymer material in the steelmaking process: before the molten steel enters the refining process, the chromium-containing geopolymer material, reducing agent and slag-forming material are added to the steelmaking converter, and the chromium element in the chromium-containing geopolymer material is reduced to metallic chromium by the reducing agent so that it can enter the molten steel.

[0022] Preferably, the reducing agent is one or more of coke, carbon powder, ferrosilicon and aluminum powder; the slag-forming material is one or more of calcium oxide, silicon dioxide or magnesium oxide; and the mass ratio of the chromium-containing geopolymer material, reducing agent and slag-forming material is 4-12:0-4:2-15.

[0023] The beneficial effects of this invention are:

[0024] This invention utilizes geopolymer technology to obtain the desired chromium-containing geopolymer materials through adsorption and direct incorporation methods. Compared with existing preparation technologies, the method for preparing chromium-containing geopolymer materials using this invention features a simple process flow, one-step molding, environmental friendliness, and low cost. The raw materials for the chromium-containing geopolymer materials prepared by this invention are widely available, falling within the field of hazardous waste treatment. Furthermore, the simple process and low production cost enable large-scale treatment of chromium-containing wastewater and further application of the chromium-containing geopolymer materials in the steelmaking industry. Without increasing equipment investment or altering existing production processes, it offers better economic benefits, achieving high-value-added utilization of solid waste resources and significantly reducing environmental pollution from ferrochrome alloys. The chromium-containing geopolymer materials prepared by this method have significant advantages and promising application prospects in the steelmaking process. Furthermore, the chromium-containing geopolymer material described in this invention, as observed by scanning electron microscopy, exhibits a good overall structure and a certain strength. Cyclic adsorption experiments revealed that a 40.45% removal rate of chromium ions was still achieved in the fourth cycle, indicating that the chromium-containing geopolymer material possesses good mechanical properties and reusability. In the steelmaking process, it can partially or completely replace ferrochrome alloys, significantly reducing the smelting cost of chromium-containing steel. Attached Figure Description

[0025] Figure 1 Optical microscope (A), scanning electron microscope (B), and energy dispersive spectroscopy (EDS) image (C) of the electrolytic manganese slag / slag-based polymer microsphere material prepared in Example 1;

[0026] Figure 2 Optical microscope images of the electrolytic manganese slag / slag-based polymer microspheres prepared in Examples 2-3;

[0027] Figure 3 Optical microscope images of the red mud / slag-based polymer microspheres prepared in Examples 4-6;

[0028] Figure 4 Optical microscope images of the geopolymer microspheres prepared in Examples 7-10;

[0029] Figure 5 Optical microscope images of the electrolytic manganese slag / slag-based polymer materials prepared in Examples 11-13;

[0030] Figure 6 Optical microscope images of the red mud / slag-based polymer materials prepared in Examples 14-16;

[0031] Figure 7 Optical microscope images of the geopolymer materials prepared in Examples 17-20. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1:

[0034] (1) 18g of slag, 12g of electrolytic manganese slag, 14g of water glass (modulus 1.7) and 12g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry.

[0035] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0036] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1200 r / min.

[0037] (4) The dimethyl silicone oil containing electrolytic manganese slag-based polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 2 hours.

[0038] (5) The dimethyl silicone oil and its product obtained in step (4) were vacuum filtered, washed and dried to obtain electrolytic manganese slag / slag-based polymer microspheres with different particle sizes.

[0039] (6) Weigh 0.15g of the obtained electrolytic manganese slag / slag-based polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ In the solution containing chromium wastewater, after shaking in a horizontal shaking table for 2 hours, the adsorption capacity and removal rate were 65.39 mg / g and 98.09%, respectively, indicating that the geopolymer microsphere material prepared in this embodiment effectively removes chromium from the wastewater. 3+ It has a good adsorption effect, and after solid-liquid separation, chromium-containing electrolytic manganese slag / slag-based polymer microspheres can be obtained;

[0040] (7) The electrolytic manganese slag / slag-based polymer microspheres obtained in Example 1 were observed using an optical microscope. The chromium-containing electrolytic manganese slag / slag-based polymer microspheres were observed using a scanning electron microscope and subjected to energy dispersive spectroscopy analysis. Figure 1 As shown, the electrolytic manganese slag / slag-based polymer microspheres exhibit excellent sphericity, which is beneficial for solid-liquid separation in subsequent adsorption experiments. Furthermore, compared to powdered adsorbents, they are better able to simulate continuous dynamic adsorption column experiments in industrial applications. In addition, the adsorbed chromium-containing electrolytic manganese slag / slag-based polymer microspheres still retain good sphericity and a certain strength, indicating that the chromium-containing electrolytic manganese slag / slag-based polymer microspheres possess certain mechanical properties. Figure 1The energy spectrum of chromium-containing microspheres characterizes the chromium content of the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material, proving that chromium successfully appeared on the surface of the microspheres through adsorption, with a content of 32.96 wt.%.

[0041] (8) Add the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material, reducing agent (coke) and slag-forming material (calcium oxide) to the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element of the chromium-containing electrolytic manganese slag / slag-based polymer material to metallic chromium, which then enters the molten steel.

[0042] Example 2:

[0043] (1) 15g of slag, 15g of electrolytic manganese slag, 14g of water glass (modulus 1.7) and 13g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry.

[0044] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0045] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1200 r / min.

[0046] (4) The dimethyl silicone oil containing electrolytic manganese slag-based polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 2 hours.

[0047] (5) The dimethyl silicone oil and its product obtained in step (4) were vacuum filtered, washed and dried to obtain electrolytic manganese slag / slag-based polymer microspheres with different particle sizes.

[0048] (6) The electrolytic manganese slag / slag-based polymer microspheres obtained in Example 2 were observed using an optical microscope, such as... Figure 2 As shown, the electrolytic manganese slag / slag-based polymer microsphere material has a certain degree of sphericity.

[0049] (7) Weigh 0.15g of the obtained electrolytic manganese slag / slag-based polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ In the chromium-containing wastewater solution, after shaking in a horizontal shaking table for 2 hours, the adsorption capacity and removal rate were 66.65 mg / g and 99.98%, respectively, indicating that the geopolymer microsphere material prepared in this embodiment effectively removes chromium. 3+ It has a good adsorption effect, and chromium-containing red mud / slag-based polymer microspheres can be obtained after solid-liquid separation.

[0050] (8) Add the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material, reducing agent (coke) and slag-forming material (calcium oxide) to the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element of the chromium-containing electrolytic manganese slag / slag-based polymer material to metallic chromium, which then enters the molten steel.

[0051] Example 3:

[0052] (1) 12g of slag, 18g of electrolytic manganese slag, 14g of water glass (modulus 1.7) and 15g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry.

[0053] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0054] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1200 r / min.

[0055] (4) The dimethyl silicone oil containing electrolytic manganese slag-based polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 2 hours.

[0056] (5) The dimethyl silicone oil and its product obtained in step (4) were vacuum filtered, washed and dried to obtain electrolytic manganese slag / slag-based polymer microspheres with different particle sizes.

[0057] (6) The electrolytic manganese slag / slag-based polymer microsphere material obtained in Example 3 was observed under an optical microscope, such as... Figure 2 As shown, the electrolytic manganese slag / slag-based polymer microsphere material has a certain degree of sphericity.

[0058] (7) Weigh 0.15g of the obtained electrolytic manganese slag / slag-based polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e. chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity and removal rate were 65.15 mg / g and 97.73%, respectively. After solid-liquid separation, chromium-containing electrolytic manganese slag / slag-based polymer microspheres were obtained.

[0059] (8) Add the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material, reducing agent (coke) and slag-forming material (calcium oxide) to the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element of the chromium-containing electrolytic manganese slag / slag-based polymer material to metallic chromium, which then enters the molten steel.

[0060] Example 4:

[0061] (1) Mix 18g of slag, 12g of red mud, 12g of water glass (modulus 1.7) and 8g of water with a glass rod to form a geopolymer slurry;

[0062] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0063] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0064] (4) The dimethyl silicone oil containing red mud / slag base polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 2 hours.

[0065] (5) The dimethyl silicone oil and its product from step (4) were vacuum filtered, washed and dried to obtain red mud / slag-based polymer microspheres of different particle sizes.

[0066] (6) The red mud / slag-based polymer microsphere material obtained in Example 4 was observed under an optical microscope, such as... Figure 3 As shown, the formed red mud / slag-based polymer microsphere material has a certain degree of sphericity.

[0067] (7) Weigh 0.15g of the obtained red mud / slag base polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ In the chromium-containing wastewater solution, after shaking in a horizontal shaking table for 2 hours, the adsorption capacity and removal rate were 66.52 mg / g and 99.79%, respectively. The red mud / slag-based polymer microsphere material prepared in this example exhibits good adsorption capacity for chromium... 3+ It has a good adsorption effect, and chromium-containing red mud / slag-based polymer microspheres can be obtained after solid-liquid separation.

[0068] (8) Add the chromium-containing red mud / slag-based polymer microsphere material, reducing agent (coke) and slag-forming material (calcium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing red mud / slag-based polymer microsphere material into metallic chromium, which then enters the molten steel.

[0069] Example 5:

[0070] (1) Mix 15g of slag, 15g of red mud, 12g of water glass (modulus 1.7) and 10g of water with a glass rod to form a geopolymer slurry;

[0071] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0072] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0073] (4) The dimethyl silicone oil containing red mud / slag base polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 2 hours.

[0074] (5) The dimethyl silicone oil and its product from step (4) were vacuum filtered, washed and dried to obtain red mud / slag-based polymer microspheres of different particle sizes.

[0075] (6) The red mud / slag-based polymer microsphere material obtained in Example 5 was observed under an optical microscope, such as... Figure 3 As shown, the formed red mud / slag-based polymer microsphere material has a certain degree of sphericity.

[0076] (7) Weigh 0.15g of the obtained red mud / slag base polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ In the chromium-containing wastewater solution, after shaking in a horizontal shaking table for 2 hours, the adsorption capacity and removal rate were 62.15 mg / g and 93.28%, respectively. The red mud / slag-based polymer microsphere material prepared in this example exhibits good adsorption capacity for chromium... 3+ It has a good adsorption effect, and chromium-containing red mud / slag-based polymer microspheres can be obtained after solid-liquid separation.

[0077] (8) Add the chromium-containing red mud / slag-based polymer microsphere material, reducing agent (coke) and slag-forming material (calcium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing red mud / slag-based polymer microsphere material into metallic chromium, which then enters the molten steel.

[0078] Example 6:

[0079] (1) Mix 18g of slag, 12g of red mud, 12g of water glass (modulus 1.7) and 14g of water with a glass rod to form a geopolymer slurry;

[0080] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0081] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0082] (4) The dimethyl silicone oil containing red mud / slag base polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 2 hours.

[0083] (5) The dimethyl silicone oil and its product from step (4) were vacuum filtered, washed and dried to obtain red mud / slag-based polymer microspheres of different particle sizes.

[0084] (6) The red mud / slag-based polymer microsphere material obtained in Example 6 was observed under an optical microscope, such as... Figure 3 As shown, the formed red mud / slag-based polymer microsphere material has a certain degree of sphericity.

[0085] (7) Weigh 0.15g of the obtained red mud / slag base polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ In the chromium-containing wastewater solution, after shaking in a horizontal shaking table for 2 hours, the adsorption capacity and removal rate were 37.72 mg / g and 56.58%, respectively. The red mud / slag-based polymer microsphere material prepared in this example exhibits good adsorption capacity for chromium... 3+ It has a certain adsorption effect, and after solid-liquid separation, chromium-containing red mud / slag-based polymer microspheres can be obtained.

[0086] (8) Add the chromium-containing red mud / slag-based polymer microsphere material, reducing agent (coke) and slag-forming material (calcium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing red mud / slag-based polymer microsphere material into metallic chromium, which then enters the molten steel.

[0087] Example 7:

[0088] (1) Mix 15g metakaolin, 12g water glass (modulus 1.1) and 4g water with a glass rod to form a geopolymer slurry;

[0089] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0090] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0091] (4) The dimethyl silicone oil containing metakaolin-based polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 1 hour.

[0092] (5) Vacuum filter, wash and dry the dimethyl silicone oil and the product obtained in step (4) to obtain metakaolin-based polymer microspheres with different particle sizes prepared by water glass excitation.

[0093] (6) The metakaolin-based polymer microsphere material obtained in Example 7 was observed under an optical microscope, such as... Figure 4 As shown, the metakaolin-based polymer microsphere material exhibits good sphericity and uniform particle size.

[0094] (7) Weigh 0.15g of the obtained metakaolin-based polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 8.91 mg / g. After solid-liquid separation, chromium-containing metakaolin-based polymer microspheres were obtained.

[0095] (8) Chromium-containing metakaolin-based polymer microspheres, reducing agent (aluminum powder) and slag-forming material (silicon dioxide) are added to the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing metakaolin-based polymer microspheres to metallic chromium, which then enters the molten steel.

[0096] Example 8:

[0097] (1) Mix 15g of metakaolin, 3g of red mud, 12g of water glass (modulus 1.1) and 5g of water with a glass rod to form a geopolymer slurry;

[0098] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0099] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0100] (4) The dimethyl silicone oil containing red mud / meta-kaolin base polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 1 hour.

[0101] (5) Vacuum filter the dimethyl silicone oil and the product obtained in step (4), wash and dry to obtain red mud / meta-kaolin base polymer microspheres with different particle sizes.

[0102] (6) The red mud / metakaolin-based polymer microspheres obtained in Example 8 were observed using an optical microscope, such as... Figure 4 As shown, the red mud / metakaolin base polymer microsphere material has good sphericity and uniform particle size.

[0103] (7) Weigh 0.15g of the obtained red mud / metakaolin base polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 3.24 mg / g. The red mud / metakaolin-based polymer microsphere material prepared in this example exhibits good adsorption for chromium... 3+ It has a certain adsorption effect, and after solid-liquid separation, chromium-containing red mud / metakaolin-based polymer microspheres can be obtained.

[0104] (8) Add the chromium-containing red mud / meta-kaolin base polymer microsphere material, reducing agent (aluminum powder) and slag-forming material (silicon dioxide) into the steelmaking converter in a mass ratio of 5:2:8. The chromium element in the chromium-containing red mud / meta-kaolin base polymer microsphere material is reduced to metallic chromium by the reducing agent and then enters the molten steel.

[0105] Example 9:

[0106] (1) Mix 30g of slag with alkali activation activity, 14g of water glass (modulus 1.7) and 12g of water with a glass rod and stir evenly to form a geopolymer slurry;

[0107] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0108] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0109] (4) The dimethyl silicone oil containing slag-based polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 5 minutes.

[0110] (5) Vacuum filter the dimethyl silicone oil and the product obtained in step (4), wash and dry to obtain slag-based polymer microspheres with different particle sizes.

[0111] (6) The slag-based polymer microsphere material obtained in Example 9 was observed under an optical microscope, such as... Figure 4 As shown, the slag-based polymer microsphere material exhibits good sphericity and uniform particle size.

[0112] (7) Weigh 0.15g of the obtained slag-based polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 66.58 mg / g, with a removal rate of 99.87%. The slag-based polymer microsphere material prepared in this embodiment exhibits good adsorption for chromium... 3+ It has a good removal effect, and after solid-liquid separation, slag-containing macropolymer microspheres can be obtained.

[0113] (8) Add the chromium-containing slag-based polymer microsphere material, reducing agent (aluminum powder) and slag-forming material (silicon dioxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing slag-based polymer microsphere material into metallic chromium, which then enters the molten steel.

[0114] Example 10:

[0115] (1) Mix 15g metakaolin, 3g slag, 12g water glass (modulus 1.1) and 4g water with a glass rod to form a geopolymer slurry;

[0116] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0117] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0118] (4) The dimethyl silicone oil containing metakaolin / slag-based polymer microspheres from step (3) is placed in an oven at 85°C for curing and solidification for 2 hours.

[0119] (5) Vacuum filter the dimethyl silicone oil and the product obtained in step (4), wash and dry to obtain metakaolin / slag-based polymer microspheres with different particle sizes prepared by water glass excitation.

[0120] (6) The metakaolin / slag-based polymer microsphere material obtained in Example 10 was observed under an optical microscope, such as... Figure 4 As shown, the metakaolin / slag-based polymer microsphere material exhibits good sphericity and uniform particle size.

[0121] (7) Weigh 0.15g of the obtained metakaolin / slag-based polymer microsphere material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 6.78 mg / g. The metakaolin / slag-based polymer microsphere material prepared in this example exhibits good adsorption for chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing metakaolin / slag-based polymer microspheres can be obtained.

[0122] (8) Chromium-containing metakaolin / slag-based polymer microspheres, reducing agent (aluminum powder) and slag-forming material (silicon dioxide) are added to the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing metakaolin / slag-based polymer material to metallic chromium, which then enters the molten steel.

[0123] Example 11:

[0124] (1) 12g of electrolytic manganese slag, 18g of slag, 14g of water glass (modulus 1.7) and 14g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry.

[0125] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0126] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0127] (4) Place the mold containing the electrolytic manganese slag-based polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0128] (5) Take out the mold containing the electrolytic manganese slag-based polymer from step (4), and demold it at room temperature to obtain the electrolytic manganese slag / slag-based polymer block;

[0129] (6) After crushing and sieving the electrolytic manganese slag / slag-based polymer blocks obtained in step (5), the electrolytic manganese slag / slag-based polymer material can be obtained. For example Figure 5 The image shown is an optical microscope image of the crushed electrolytic manganese slag / slag-based polymer material obtained in Example 11.

[0130] (7) Weigh 0.15g of the obtained electrolytic manganese slag / slag-based polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 65.27 mg / g. The electrolytic manganese slag / slag-based polymer material prepared in this example exhibits good adsorption of chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing electrolytic manganese slag / slag-based polymer microspheres can be obtained.

[0131] (8) Add the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material, reducing agent (aluminum powder) and slag-forming material (silicon dioxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing electrolytic manganese slag / slag-based polymer material into metallic chromium, which then enters the molten steel.

[0132] Example 12:

[0133] (1) 15g of electrolytic manganese slag, 15g of slag, 14g of water glass (modulus 1.7) and 18g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry.

[0134] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0135] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0136] (4) Place the mold containing the electrolytic manganese slag-based polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0137] (5) Take out the mold containing the electrolytic manganese slag-based polymer from step (4), and demold it at room temperature to obtain the electrolytic manganese slag / slag-based polymer block;

[0138] (6) After crushing and sieving the electrolytic manganese slag / slag-based polymer blocks obtained in step (5), the electrolytic manganese slag / slag-based polymer material can be obtained. For example Figure 5 The image shown is an optical microscope image of the crushed electrolytic manganese slag / slag-based polymer material obtained in Example 12.

[0139] (7) Weigh 0.15g of the obtained electrolytic manganese slag / slag-based polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 66.63 mg / g. The electrolytic manganese slag / slag-based polymer material prepared in this example exhibits good adsorption of chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing electrolytic manganese slag / slag-based polymer microspheres can be obtained.

[0140] (8) Add the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material, reducing agent (aluminum powder) and slag-forming material (silicon dioxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing electrolytic manganese slag / slag-based polymer material into metallic chromium, which then enters the molten steel.

[0141] Example 13:

[0142] (1) 18g of electrolytic manganese slag, 12g of slag, 14g of water glass (modulus 1.7) and 20g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry.

[0143] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0144] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0145] (4) Place the mold containing the electrolytic manganese slag-based polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0146] (5) Take out the mold containing the electrolytic manganese slag-based polymer from step (4), and demold it at room temperature to obtain the electrolytic manganese slag / slag-based polymer block;

[0147] (6) After crushing and sieving the electrolytic manganese slag / slag-based polymer blocks obtained in step (5), the electrolytic manganese slag / slag-based polymer material can be obtained. For example Figure 5The image shown is an optical microscope image of the crushed electrolytic manganese slag / slag-based polymer material obtained in Example 13.

[0148] (7) Weigh 0.15g of the obtained electrolytic manganese slag / slag-based polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 65.20 mg / g. The electrolytic manganese slag / slag-based polymer material prepared in this example exhibits good adsorption of chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing electrolytic manganese slag / slag-based polymer microspheres can be obtained.

[0149] (8) Add the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material, reducing agent (aluminum powder) and slag-forming material (silicon dioxide) to the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing electrolytic manganese slag / slag-based polymer material to metallic chromium, which then enters the molten steel.

[0150] Example 14:

[0151] (1) Mix 12g of red mud, 18g of slag, 12g of water glass (modulus 1.7) and 8g of water with a glass rod to form a geopolymer slurry;

[0152] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0153] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0154] (4) Place the mold containing the red mud base polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0155] (5) Take out the mold containing the red mud base polymer from step (4) and demold it at room temperature to obtain the red mud / slag base polymer block;

[0156] (6) The red mud / slag base polymer blocks obtained in step (5) are crushed and sieved to obtain the red mud / slag base polymer material. For example... Figure 6 The image shown is an optical microscope image of the crushed red mud / slag base polymer material obtained in Example 14.

[0157] (7) Weigh 0.15g of the obtained red mud / slag base polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 66.55 mg / g. The red mud / slag-based polymer material prepared in this example exhibits good adsorption of chromium...3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing red mud / slag-based polymer materials can be obtained.

[0158] (8) Add the chromium-containing red mud / slag base polymer material, reducing agent (ferrosilicon) and slag-forming material (magnesium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing red mud / slag base polymer material into metallic chromium, which then enters the molten steel.

[0159] Example 15:

[0160] (1) Mix 15g of red mud, 15g of slag, 12g of water glass (modulus 1.7) and 10g of water with a glass rod to form a geopolymer slurry;

[0161] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0162] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0163] (4) Place the mold containing the red mud base polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0164] (5) Take out the mold containing the red mud base polymer from step (4) and demold it at room temperature to obtain the red mud / slag base polymer block;

[0165] (6) The red mud / slag base polymer blocks obtained in step (5) are crushed and sieved to obtain the red mud / slag base polymer material. For example... Figure 6 The image shown is an optical microscope image of the crushed red mud / slag base polymer material obtained in Example 15.

[0166] (7) Weigh 0.15g of the obtained red mud / slag base polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 62.21 mg / g. The red mud / slag-based polymer material prepared in this example exhibits good adsorption of chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing red mud / slag-based polymer materials can be obtained.

[0167] (8) Add the chromium-containing red mud / slag base polymer material, reducing agent (ferrosilicon) and slag-forming material (magnesium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing red mud / slag base polymer material into metallic chromium, which then enters the molten steel.

[0168] Example 16:

[0169] (1) Mix 18g of red mud, 12g of slag, 12g of water glass (modulus 1.7) and 14g of water with a glass rod to form a geopolymer slurry;

[0170] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0171] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0172] (4) Place the mold containing the red mud base polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0173] (5) Take out the mold containing the red mud base polymer from step (4) and demold it at room temperature to obtain the red mud / slag base polymer block;

[0174] (6) The red mud / slag base polymer blocks obtained in step (5) are crushed and sieved to obtain the red mud / slag base polymer material. For example... Figure 6 The image shown is an optical microscope image of the crushed red mud / slag base polymer material obtained in Example 16.

[0175] (7) Weigh 0.15g of the obtained red mud / slag base polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 35.28 mg / g. The red mud / slag-based polymer material prepared in this example exhibits good adsorption of chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing red mud / slag-based polymer materials can be obtained.

[0176] (8) Add the chromium-containing red mud / slag base polymer material, reducing agent (ferrosilicon) and slag-forming material (magnesium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing red mud / slag base polymer material into metallic chromium, which then enters the molten steel.

[0177] Example 17:

[0178] (1) Mix 15g metakaolin, 12g water glass (modulus 1.1) and 4g water with a glass rod to form a geopolymer slurry;

[0179] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0180] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0181] (4) Place the mold containing metakaolin base polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0182] (5) Take out the mold containing metakaolin-based polymer from step (4), and demold it at room temperature to obtain the metakaolin-based polymer block;

[0183] (6) The metakaolin-based polymer blocks obtained in step (5) are crushed and sieved to obtain the metakaolin-based polymer material. For example... Figure 7 The image shown is an optical microscope image of the crushed metakaolin-based polymer material obtained in Example 17.

[0184] (7) Weigh 0.15g of the obtained metakaolin-based polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 7.98 mg / g. The metakaolin-based polymer material prepared in this example exhibits high adsorption capacity for chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing metakaolin-based polymer materials can be obtained.

[0185] (8) Add the chromium-containing metakaolin-based polymer material, reducing agent (ferrosilicon) and slag-forming material (magnesium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing metakaolin-based polymer material into metallic chromium, which then enters the molten steel.

[0186] Example 18:

[0187] (1) Mix 15g of metakaolin, 3g of red mud, 12g of water glass (modulus 1.1) and 5g of water with a glass rod to form a geopolymer slurry;

[0188] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0189] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0190] (4) Place the mold containing red mud / metakaolin base polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0191] (5) Take out the mold containing red mud / meta-kaolin base polymer from step (4), and demold at room temperature to obtain red mud / meta-kaolin base polymer block;

[0192] (6) The red mud / metakaolin base polymer blocks obtained in step (5) are crushed and sieved to obtain the red mud / metakaolin base polymer material. For example Figure 7 The image shown is an optical microscope image of the crushed red mud / metakaolin base polymer material obtained in Example 18.

[0193] (7) Weigh 0.15g of the obtained red mud / metakaolin base polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 3.12 mg / g. The red mud / metakaolin-based polymer material prepared in this example exhibits good adsorption of chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing red mud / metakaolin-based polymer materials can be obtained.

[0194] (8) Add the chromium-containing red mud / meta-kaolin base polymer material, reducing agent (ferrosilicon) and slag-forming material (magnesium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing red mud / meta-kaolin base polymer material into metallic chromium, which then enters the molten steel.

[0195] Example 19:

[0196] (1) Mix 30g of slag with alkali activation activity, 14g of water glass (modulus 1.7) and 12g of water with a glass rod and stir evenly to form a geopolymer slurry;

[0197] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0198] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0199] (4) Place the mold containing slag-based polymer from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0200] (5) Take out the mold containing slag-based polymer from step (4) and demold it at room temperature to obtain the slag-based polymer block;

[0201] (6) The slag-based polymer blocks obtained in step (5) are crushed and sieved to obtain slag-based polymer materials. For example... Figure 7 The image shown is an optical microscope image of the crushed slag-based polymer material obtained in Example 19.

[0202] (7) Weigh 0.15g of the obtained slag-based polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 66.45 mg / g. The slag-based polymer material prepared in this example exhibits high adsorption capacity for chromium... 3+ It has a certain removal effect, and chromium-containing slag-based polymer materials can be obtained after solid-liquid separation.

[0203] (8) Add the chromium-containing slag base polymer material, reducing agent (ferrosilicon) and slag-forming material (magnesium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing slag base polymer material into metallic chromium, which then enters the molten steel.

[0204] Example 20:

[0205] (1) Mix 15g metakaolin, 3g slag, 12g water glass (modulus 1.1) and 4g water with a glass rod to form a geopolymer slurry;

[0206] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0207] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0208] (4) Place the mold containing metakaolin / slag aggregate from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0209] (5) Take out the mold containing metakaolin / slag base polymer from step (4), and demold it at room temperature to obtain the metakaolin / slag base polymer block;

[0210] (6) The metakaolin / slag-based polymer blocks obtained in step (5) are crushed and sieved to obtain the metakaolin / slag-based polymer material. For example... Figure 7 The image shown is an optical microscope image of the crushed metakaolin / slag-based polymer material obtained in Example 20.

[0211] (7) Weigh 0.15g of the obtained metakaolin / slag-based polymer material into 100mL of Cr solution with a concentration of 100ppm. 3+ The solution, i.e., chromium-containing wastewater, was shaken in a horizontal shaking table for 2 hours, and the adsorption capacity was 8.89 mg / g. The metakaolin / slag-based polymer material prepared in this example exhibits good adsorption of chromium... 3+ It has a certain removal effect, and after solid-liquid separation, chromium-containing metakaolin / slag-based polymer materials can be obtained.

[0212] (8) Add the chromium-containing metakaolin / slag base polymer material, reducing agent (ferrosilicon) and slag-forming material (magnesium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing metakaolin / slag base polymer material into metallic chromium, which then enters the molten steel.

[0213] The electrolytic manganese slag / slag-based polymer materials prepared under the process conditions of Examples 1-3 and 11-13 have a positive effect on Cr. 3+ The removal rates of Cr were all above 96%. From the above examples, it can be seen that... 3+ The adsorption results show that with the increase of electrolytic manganese slag content, the adsorption of Cr by electrolytic manganese slag / slag matrix polymer materials increases. 3+ It still maintains good adsorption performance because electrolytic manganese slag is rich in silicate minerals and iron-manganese oxides, which have a good fixation and adsorption effect on heavy metals. Therefore, increasing the amount of electrolytic manganese slag will have a positive effect on Cr. 3+ The adsorption effect is not significantly affected; the adsorption effect of the electrolytic manganese slag / slag-based polymer material on Cr is minimal. 3+ It still has a good adsorption effect.

[0214] Red mud / slag-based polymer materials were prepared using the process conditions of Examples 4 and 5 and Examples 14 and 15. The red mud / slag-based polymer materials prepared in Examples 4 and 14 showed good Cr content. 3+ The removal rate was over 97%, while the red mud / slag-based polymer materials prepared in Examples 5 and 15 showed a better removal rate for Cr. 3+ The removal rate is only about 90%. From the above examples, the removal rate of Cr... 3+ The adsorption results show that the red mud / slag-based polymer material has good adhesion to Cr. 3+ The good adsorption effect is due to the C-(A)-SH gel phase and its iron-manganese oxides in the red mud / slag matrix polymer, which have a good effect on Cr. 3+ It exhibits good adsorption properties. However, with the increase of red mud content, the red mud / slag matrix polymer's adsorption of Cr... 3+ The adsorption performance of Cr decreased because when the red mud content increased significantly, aluminum and silicon in the red mud became less soluble, and the large amount of hematite in the red mud inhibited the geopolymerization reaction. Therefore, the reduced reactivity of the geopolymerization reaction led to a decrease in the C-(A)-SH gel phase in the red mud / slag geopolymer, thus reducing its adsorption capacity. 3+ The adsorption effect is reduced.

[0215] The slag-based polymer materials prepared under the process conditions of Examples 9 and 19 have a positive effect on Cr. 3+ The removal rates of Cr were all above 96%. From the above examples, it can be seen that... 3+ The adsorption results show that the polymer material in the slag base has good adhesion to Cr. 3+It exhibits good adsorption performance because slag is an amorphous aluminosilicate precursor material. Under alkaline conditions, it undergoes depolymerization-condensation reaction to generate a geopolymer gel material with a three-dimensional network structure, containing a large amount of C-(A)-SH gel phase, which is effective for adsorption of Cr. 3+ It exhibits good adsorption properties, thus slag-based polymer materials are a good chromium adsorbent. Examples 6 and 16 show that excessive red mud addition leads to a decrease in the C-(A)-SH gel phase content, reducing the adsorption capacity for chromium. 3+ The adsorption capacity of the metakaolin-based polymer materials prepared in Examples 7 and 17, the red mud / metakaolin-based polymer materials prepared in Examples 8 and 18, and the metakaolin / slag-based polymer materials prepared in Examples 10 and 20 showed poor adsorption of chromium ions. This is because metakaolin mainly consists of SiO2 and Al2O3, and the geopolymerization process primarily generates a NASH gel phase, which is not conducive to the adsorption of chromium ions. 3+ Adsorption is a factor, therefore metakaolin-based polymer materials have poor adsorption capacity for chromium ions.

[0216] Example 21:

[0217] (1) 18g of slag, 12g of electrolytic manganese slag, 14g of water glass (modulus 1.7) and 12g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry; a certain amount of chromium nitrate nonahydrate is added in the above steps, and its content is calculated as 7% of the total mass of the geopolymer.

[0218] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0219] (3) The geopolymer slurry from step (2) is slowly injected into dimethyl silicone oil at 85°C with a stirring speed of 1000 r / min.

[0220] (4) The dimethyl silicone oil of the chromium-containing geopolymer microsphere material from step (3) is placed in an oven at 85°C for curing and curing for 2 hours.

[0221] (5) The dimethyl silicone oil and its product obtained in step (4) were vacuum filtered, washed and dried to obtain chromium-containing geopolymer microspheres with different particle sizes.

[0222] (6) Add the chromium-containing geopolymer microsphere material, reducing agent (carbon powder) and slag-forming material (calcium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing geopolymer microsphere material into metallic chromium, which then enters the molten steel.

[0223] Example 22:

[0224] (1) 15g of slag, 15g of electrolytic manganese slag, 14g of water glass (modulus 1.7) and 13g of sodium hydroxide (10mol / L) are mixed and stirred evenly with a glass rod to form a geopolymer slurry; a certain amount of chromium nitrate nonahydrate is added in the above steps, the content of which is calculated as 8% of the total mass of the geopolymer.

[0225] (2) Disperse the slurry in a disperser at a stirring speed of 2000 r / min for 1 min to ensure complete reaction;

[0226] (3) Inject the geopolymer slurry from step (2) into the mold and vibrate it up and down for 5 minutes to eliminate air bubbles;

[0227] (4) Place the mold of the chromium-containing geopolymer slurry from step (3) into an oven at 85°C for curing and solidification for 2 hours.

[0228] (5) Take out the mold of the chromium-containing geopolymer material from step (4) and demold it at room temperature to obtain the chromium-containing geopolymer block;

[0229] (6) The chromium-containing geopolymer block obtained in step (5) is crushed and sieved to obtain the chromium-containing geopolymer material;

[0230] (7) Add the chromium-containing geopolymer material, reducing agent (carbon powder) and slag-forming material (calcium oxide) into the steelmaking converter in a mass ratio of 5:2:8. The reducing agent reduces the chromium element in the chromium-containing geopolymer material into metallic chromium, which then enters the molten steel.

[0231] The following is a comparison of applications when using the same batch of raw materials to produce chromium steel, under identical production conditions:

[0232] Existing technology: After the initial refining of molten steel, 43 kg of ferrochrome alloy (FeCr55C2.0) is added per ton of molten steel during the tapping process. During the first refining, 36 kg of ferrochrome alloy (FeCr55C2.0) is added per ton of molten steel. During the second refining, 0.1 kg of ferrochrome alloy (FeCr60C0.1) is added per ton of molten steel. The Cr content in the final chromium steel composition is 4.1 wt%.

[0233] Example 1 of this invention: After the initial refining of molten steel, during the tapping process, 43 kg of ferrochrome alloy (FeCr55C2.0) is added per ton of molten steel. During the first refining, 58 kg of the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material prepared in Example 1 is added per ton of molten steel (along with the addition of reducing agent and slagging agent in a set ratio). During the second refining, 1 kg of the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material prepared in Example 1 is added per ton of molten steel (along with the addition of reducing agent and slagging agent in a set ratio). The Cr content in the final chromium steel composition is 3.9 wt%.

[0234] Example 22 of this invention: After the initial refining of molten steel, during the tapping process, 43 kg of ferrochrome alloy (FeCr55C2.0) is added per ton of molten steel. During the first refining, 58 kg of the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material prepared in Example 22 is added per ton of molten steel (with reducing agent and slag-forming agent added in a set ratio at the same time). During the second refining, 1 kg of the chromium-containing electrolytic manganese slag / slag-based polymer microsphere material prepared in Example 22 is added per ton of molten steel (with reducing agent and slag-forming agent added in a set ratio at the same time). The Cr content in the final chromium steel composition is 4.0 wt%.

[0235] It is evident that the chromium-containing geopolymer material prepared by this invention can partially replace ferrochrome alloys in the steelmaking process, reducing the smelting cost of chromium-containing steel. In summary, this invention not only enables large-scale treatment and application of chromium-containing wastewater, but also allows the chromium-containing geopolymer material to be further applied in the steelmaking industry. Without increasing equipment investment or changing existing production processes, it offers better economic benefits and achieves high-value-added utilization of solid waste resources. The chromium-containing geopolymer material prepared by this method has significant advantages and application prospects in the steelmaking process. Furthermore, the chromium-containing geopolymer material prepared by the adsorption method for chromium-containing wastewater in Example 1 and the chromium-containing geopolymer material prepared by the direct incorporation of chromium compounds in Example 22 show similar effects, proving that the method of this invention can effectively treat chromium-containing wastewater while reducing the smelting cost of chromium steel.

[0236] The above description is not intended to limit the present invention in any way. Although the present invention has been disclosed through the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. Use of a chromium-containing polygeomer material in a steelmaking process, characterized in that: The chromium-containing geopolymer material, a reducing agent and a slagging material are added into a steelmaking converter, and the chromium element in the chromium-containing geopolymer material is reduced into metallic chromium by the reducing agent to enter the molten steel; the preparation of the chromium-containing geopolymer material includes adding chromium ions into the geopolymer material by a direct incorporation method; The preparation of the chromium-containing geopolymer material by the direct incorporation method includes the following steps: S1: stirring and dispersing raw materials with certain activity, activators, chromium-containing compounds and water to obtain chromium-containing slurry; the mass ratio of the raw materials with certain activity, activators, chromium-containing compounds and water is 2-10:5-10:1-4:0-4; S2: pouring the chromium-containing slurry into dispersed hot dimethyl silicone oil after complete reaction in a disperser to disperse the chromium-containing slurry into balls, and then performing solidification, vacuum filtration, washing and drying; or pouring the chromium-containing slurry into a mold after complete reaction in a disperser, and then performing up-down vibration to eliminate air bubbles, curing, demolding and crushing and sieving to obtain chromium-containing geopolymer materials with different particle sizes.

2. Use of a chromium-containing polygeomer material according to claim 1 in a steelmaking process, characterized in that: In step S1, the raw materials with certain activity include one or more of blast furnace granulated slag, metakaolin, red mud, steel slag, electrolytic manganese slag, fly ash, silica ash powder and rice husk ash; the activators include acid activators and alkaline activators, the acid activators are one or more of hydrochloric acid, phosphoric acid, nitric acid and sulfuric acid; and the alkaline activators are one or more of sodium / potassium hydroxide solution, sodium / potassium dry powder water glass and sodium / potassium liquid water glass.

3. Use of a chromium-containing polygeomer material in a steelmaking process according to claim 1, characterized in that: In step S1, the chromium-containing compounds include one or more of chromium nitrate nonahydrate, chromium chloride and chromium sulfate.

4. Use of a chromium-containing polygeomer material according to claim 1 in the steelmaking process, characterized in that: In step S2, the dispersion speed of the slurry / chromium-containing slurry in the disperser is 100-4500 rpm, and the dispersion time is 1-20 min; the stirring speed of the dimethyl silicone oil is 100-3000 rpm, and the temperature of the dimethyl silicone oil and the curing temperature are both 20-200℃.

5. Use of a chromium-containing polygeomer material according to claim 1 in a steelmaking process, characterized in that: In step S2, the up-down vibration time is 1 min-50 min, the curing temperature is 20-200℃, and the curing time is 2 min-96 h; the geopolymer materials with different particle sizes include one or more of powder, granules or small block materials, and the size is 1-500 μm.

6. Use of a chromium-containing polygeomer material according to claim 1 in a steelmaking process, characterized in that: The reducing agent is one or more of coke, carbon powder, silicon iron and aluminum powder; the slagging material is one or more of calcium oxide, silicon dioxide and magnesium oxide; and the mass ratio of the chromium-containing geopolymer material, the reducing agent and the slagging material is 4-12:0-4:2-15.

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