A sulfur-modified calcium-aluminum compound, a preparation method thereof, and a method for removing chlorine and thallium ions in desulfurization wastewater and application of a chlorine / thallium removal product

Abstract

The application discloses a sulfur-modified calcium-aluminum compound, a preparation method of the sulfur-modified calcium-aluminum compound, a method for removing chlorine ions and thallium ions in desulfurization wastewater, and application of a chlorine / thallium removal product, and the preparation method of the sulfur-modified calcium-aluminum compound comprises the following steps: mixing a calcium source and an aluminum source, and then calcining to obtain a calcium-aluminum compound; and then mixing a sulfide solution with the calcium-aluminum compound to react, and then drying and grinding a product to obtain the sulfur-modified calcium-aluminum compound. The sulfur-modified calcium-aluminum compound obtained through the preparation method can effectively remove chlorine ions and thallium ions in desulfurization wastewater, and the obtained chlorine / thallium removal product can be recycled to prepare long-afterglow luminescent microcrystalline glass.

Description

Technical Field

[0001] This invention relates to a sulfur-modified calcium-aluminum compound and its preparation method, as well as a method for removing chloride and thallium ions from desulfurization wastewater and the application of the dechlorination / thallium products, belonging to the field of wastewater treatment technology and product reuse technology. Background Technology

[0002] Industrial desulfurization wastewater contains high levels of chloride, severely impacting the ecological environment. Direct discharge without treatment will pollute large amounts of water sources, significantly affecting agriculture, fisheries, and forestry, and even contaminating groundwater. Excessive chloride levels in water can cause severe erosion, corroding metal pipes and buildings; in soil, it can lead to soil compaction and salinization, and potentially cause poisoning in organisms and humans. Studies show that chloride ion concentrations in water reaching 1500 mg / L can harm livestock and poultry, and concentrations exceeding 4000 mg / L can cause death.

[0003] Heavy metal pollution in water bodies is a global problem that has received high attention from countries worldwide. Heavy metal pollutants are hazardous wastes with teratogenic, carcinogenic, and mutagenic properties. They can migrate into the food chain with water flow and accumulate in organisms, ultimately endangering human health. Due to the complex and variable conditions of actual water bodies, the purification of toxic heavy metal ions remains a serious challenge. Therefore, exploring suitable methods to remove heavy metal ions from actual water bodies is of great significance.

[0004] Thallium is a common and highly toxic substance. With industrial development, large quantities of thallium enter the environment through steel smelting, lead and zinc smelting, chemical processing, and pigment manufacturing. During the high-temperature calcination of thallium-containing metal ores, most of the thallium enters the dust removal flue gas, then is recycled and gradually enriched in the wet desulfurization spray, producing higher concentrations of thallium-containing desulfurization wastewater. This wastewater can easily leach into surface water bodies through rainwater or flushing water. Through bioaccumulation, it can be ingested by humans, harming human health, deteriorating water quality, and harming flora and fauna.

[0005] calcium aluminum stone (Ca 12 Al 14 0 33 Calcium aluminum oxide (CAO) is a promising functional material with a cage-like crystal structure in the CaO-Al₂O₃ binary system. It exhibits good room temperature stability, is easily doped with various metal ions, and can transform from an insulator to a conductor, making it a promising candidate for applications in electronic devices, electrochemistry, catalysis, and sensing elements. Porous bulk materials, due to their unique pore structure, have been widely used in filtration, separation, adsorption, electrochemistry, and optoelectronic devices. However, current methods for treating chloride ions in desulfurization wastewater using CAO still suffer from problems such as high dosage and low efficiency. Furthermore, CAO cannot effectively treat thallium ions in desulfurization wastewater.

[0006] Sulfidation is one of the most effective surface modification technologies, and sulfided materials have been widely used in environmental remediation and wastewater engineering. Therefore, it is necessary to modify calcium aluminum stone to make it compatible with sulfides, improve its reactivity with thallium, and simultaneously remove chloride and thallium ions from desulfurization wastewater. Summary of the Invention

[0007] To improve the efficiency of calcium aluminum ore in treating chloride and thallium ions in desulfurization wastewater while reducing the amount of calcium aluminum ore added, this invention provides a sulfur-modified calcium aluminum compound, its preparation method, a method for removing chloride and thallium ions from desulfurization wastewater, and the application of the dechlorination / thallium products. Sulfur is introduced into calcium aluminum ore to obtain a sulfur-modified calcium aluminum compound. Using this material in desulfurization wastewater treatment can significantly improve degradation efficiency, reduce the amount of sulfur-modified calcium aluminum compound used, lower costs, and also enable the recycling of dechlorination / thallium products.

[0008] The technical solution adopted in this invention is as follows:

[0009] A method for preparing a sulfur-modified calcium-aluminum compound includes the following steps:

[0010] A calcium-aluminum compound is obtained by calcining a mixture of calcium and aluminum sources; then, a sulfide solution is mixed with the calcium-aluminum compound and reacted, and the product is dried and ground to obtain the sulfur-modified calcium-aluminum compound.

[0011] The calcium source and aluminum source are mixed in a Ca:Al molar ratio of (1-1.3):1; the mass ratio of sulfide to calcium-aluminum compound in the sulfide solution is (0.1-2):1.

[0012] Preferably, the calcination conditions are: 800-1400℃, 1-6h, and heating rate of 3-5℃ / min.

[0013] Preferably, the calcium source is one or more of calcium oxide, calcium hydroxide, calcium carbonate, carbide slag, calcium bicarbonate, and calcium nitrate.

[0014] The aluminum source is one or more of aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum carbonate, aluminum silicate, and ferric aluminate.

[0015] Preferably, the sulfide solution is obtained by dissolving sulfide in water, and the concentration of the sulfide solution is 0.1-10 mol / L;

[0016] The sulfide is one or more of sodium sulfide, thiourea, potassium sulfide, zinc sulfide, magnesium sulfide, ferrous sulfide, manganese sulfide, calcium sulfide, and thioacetamide.

[0017] Preferably, the mixing reaction conditions are: under stirring, 20-60℃, 1-5h; the drying conditions are: 50-110℃.

[0018] A method for removing chloride and thallium ions from desulfurization wastewater involves adding a sulfur-modified calcium-aluminum compound prepared by any of the above methods to the desulfurization wastewater and stirring.

[0019] Preferably, the dosage of the sulfur-modified calcium-aluminum compound is 0.1-200 g / L, and the reaction time is 1-12 h.

[0020] The application of a thallium removal product in the preparation of long-afterglow luminescent microcrystalline glass is specifically to use the chlorine / thallium removal product obtained after performing any of the above-mentioned removal methods as an activator, mix it with glass matrix raw materials and luminescent materials, grind it, and then sinter it to obtain the long-afterglow luminescent microcrystalline glass.

[0021] Preferably, the glass matrix raw material includes silicates and oxides; wherein the silicates are one or more selected from silicon dioxide, quartz sand, sodium silicate, calcium silicate, aluminum silicate, magnesium silicate, iron silicate, potassium silicate, lead silicate, strontium silicate, copper silicate, and lithium silicate; and the oxides are one or more selected from sodium oxide, boron oxide, potassium oxide, magnesium oxide, and barium oxide.

[0022] The luminescent material is one or more of europium oxide, tellurium oxide, erbium oxide, ytterbium oxide, praseodymium oxide, cerium oxide, lanthanum oxide, manganese oxide, samarium oxide, neodymium oxide, and terbium oxide.

[0023] Preferably, the mass ratio of the thallium removal product, silicate, oxide, and luminescent material is 30:(30-50):(5-25):(1-5);

[0024] The firing conditions are: 1000-1300℃, 1-2 hours.

[0025] The beneficial effects of this invention are as follows:

[0026] This invention utilizes sulfidation to modify calcium aluminum stone to obtain sulfur-modified calcium aluminum compounds. The process is simple and easy to operate. The obtained sulfur-modified calcium aluminum compounds have the ability to remove chloride ions and thallium ions from desulfurization wastewater, and the chloride removal efficiency can reach 60% to 80%, and the thallium removal efficiency can reach 99.0% to 99.99%.

[0027] Furthermore, the dechlorinated / thallium-containing products can be used as one of the raw materials for long-afterglow microcrystalline glass. The thallium ions contained in the dechlorinated / thallium-containing products can promote the melting and fluidity of glass raw materials, producing uniform and transparent glass products, and also help to lower the melting point of glass; the dechlorinated / thallium-containing products can also improve the chemical stability and heat resistance of glass, giving glass products better resistance to chemical corrosion and high-temperature resistance. Attached Figure Description

[0028] Figure 1Here is a SEM image of the sulfur-modified calcium-aluminum compound in Example 1;

[0029] Figure 2 The image shows the XRD pattern of the sulfur-modified calcium-aluminum compound in Example 1.

[0030] Figure 3 This is a SEM image of the calcium aluminum stone obtained in Example 1. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] Example 1

[0033] Calcium oxide and aluminum oxide with a Ca:Al molar ratio of 1:1 were mixed and stirred thoroughly. The mixture was then placed in a muffle furnace and heated to 1200℃ at a heating rate of 5℃ / min, held at that temperature for 4 hours, and then cooled at a cooling rate of 5℃ / min until it reached 1000℃. The SEM image of the resulting calcium aluminum oxide is shown below. Figure 3 As shown, the surface is relatively smooth.

[0034] Prepare 100 mL of a 2 mol / L sodium sulfide solution, add 20 g of calcium aluminum stone, stir at room temperature for 4 hours, centrifuge, dry the solid at 80℃, and grind to obtain the sulfur-modified calcium aluminum compound. The XRD pattern of the sulfur-modified calcium aluminum compound obtained by 2 mol / L modification is shown below. Figure 2 As shown, the SEM image is as follows: Figure 1 As shown, the surface becomes rough.

[0035] The pH of a wastewater with a pH of 7.12, a chloride ion concentration of 3000 mg / L, and a thallium ion concentration of 183.16 μg / L was adjusted to 12.

[0036] 5g of sulfur-modified calcium-aluminum compound was added to 100mL of wastewater and stirred at room temperature for 4 hours at 500rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rates of chloride ions were found to be 77.30% and thallium ions 99.89%, respectively.

[0037] After the reaction, the precipitate was placed in an oven and dried at 80°C, and then ground to obtain the dechlorinated / thallium product.

[0038] Comparative Example 1

[0039] Wastewater with pH = 7.12, chloride ion concentration of 3000 mg / L, and thallium ion concentration of 183.16 μg / L was adjusted to pH 12 (same as in Example 1).

[0040] Five g of the calcium aluminum stone obtained in Example 1 was added to 100 mL of wastewater and stirred at room temperature for 4 hours at 500 rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rate of chloride ions by calcium aluminum stone was found to be 39.26%, and the removal rate of thallium ions was 38.93%.

[0041] As can be seen from the removal rate data of Example 1 and Comparative Example 1, the sulfur-modified calcium-aluminum compound has achieved a significant improvement in both chloride ion removal efficiency and thallium ion removal efficiency.

[0042] Example 2

[0043] Calcium hydroxide and ferric aluminate with a Ca:Al molar ratio of 1.1:1 were mixed and stirred evenly, and then placed in a muffle furnace and heated to 800°C at a heating rate of 5°C / min. The mixture was held at this temperature for 6 hours, and then cooled at a cooling rate of 5°C / min. The mixture was then removed when the temperature dropped to 600°C to obtain calcium aluminum stone.

[0044] Prepare 100 mL of 10 mol / L thiourea solution, add 20 g of calcium aluminum stone, stir at room temperature for 5 hours, centrifuge, dry the solid at 70 °C, and grind to obtain sulfur-modified calcium aluminum compound.

[0045] Wastewater with a pH of 10, a chloride ion concentration of 10000 mg / L, and a thallium ion concentration of 2000 μg / L was adjusted to pH 12.

[0046] 5g of sulfur-modified calcium-aluminum compound was added to 100mL of wastewater and stirred at room temperature for 4 hours at 500rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rates were found to be 62.27% for chloride ions and 99.95% for thallium ions.

[0047] After the reaction, the precipitate was placed in an oven and dried at 80°C, and then ground to obtain the dechlorinated / thallium product.

[0048] Comparative Example 2

[0049] Wastewater with a pH of 10, a chloride ion concentration of 10000 mg / L, and a thallium ion concentration of 2000 μg / L was adjusted to pH 12 (same as in Example 2).

[0050] Five g of the calcium aluminum stone obtained in Example 2 was added to 100 mL of wastewater and stirred at room temperature for 4 hours at 500 rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rate of chloride ions by calcium aluminum stone was found to be 15.22%, and the removal rate of thallium ions was 15.63%.

[0051] As can be seen from the removal rate data of Example 2 and Comparative Example 2, the sulfur-modified calcium-aluminum compound has achieved a significant improvement in both chloride ion removal efficiency and thallium ion removal efficiency.

[0052] Example 3

[0053] Calcium carbonate and aluminum carbonate with a Ca:Al molar ratio of 1.2:1 were mixed and stirred evenly, and then placed in a muffle furnace and heated to 1000℃ at a heating rate of 5℃ / min. The mixture was held at this temperature for 5 hours, and then cooled at a cooling rate of 5℃ / min. The mixture was then removed when the temperature dropped to 900℃ to obtain calcium aluminum stone.

[0054] Prepare 100 mL of 0.1 mol / L zinc sulfide solution, add 20 g of calcium aluminum stone, stir at room temperature for 3 hours, centrifuge, dry the solid at 70 °C, and grind to obtain sulfur-modified calcium aluminum compound.

[0055] Wastewater with pH=6, chloride ion concentration of 5000 mg / L, and thallium ion concentration of 10 μg / L was adjusted to pH 12.

[0056] 5g of sulfur-modified calcium-aluminum compound was added to 100mL of wastewater and stirred at room temperature for 4 hours at 500rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rates were found to be 71.48% for chloride ions and 99.90% for thallium ions.

[0057] After the reaction, the precipitate was placed in an oven and dried at 80°C, and then ground to obtain the dechlorinated / thallium product.

[0058] Comparative Example 3

[0059] Wastewater with pH=6, chloride ion concentration of 5000 mg / L, and thallium ion concentration of 10 μg / L was adjusted to pH 12 (same as in Example 3).

[0060] 5g of the calcium aluminum stone obtained in Example 3 was added to 100mL of wastewater and stirred at room temperature for 4 hours at 500rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rate of chloride ions by calcium aluminum stone was found to be 26.44%, and the removal rate of thallium ions was 55.99%.

[0061] As can be seen from the removal rate data of Example 3 and Comparative Example 3, the sulfur-modified calcium-aluminum compound has achieved a significant improvement in both chloride ion removal efficiency and thallium ion removal efficiency.

[0062] Example 4

[0063] Calcium nitrate and aluminosilicate with a Ca:Al molar ratio of 1.3:1 were mixed and stirred evenly, and then placed in a muffle furnace and heated to 1300°C at a heating rate of 5°C / min. The mixture was held at this temperature for 3 hours, and then cooled at a cooling rate of 5°C / min. The mixture was then removed when the temperature dropped to 1100°C to obtain calcium aluminum stone.

[0064] Prepare 100 mL of 3 mol / L magnesium sulfide solution, add 20 g of calcium aluminum stone, stir at room temperature for 2 hours, centrifuge, dry the solid at 60 °C, and grind to obtain sulfur-modified calcium aluminum compound.

[0065] Wastewater with pH=8, chloride ion concentration of 2000 mg / L, and thallium ion concentration of 300 μg / L was adjusted to pH 12.

[0066] 5g of sulfur-modified calcium-aluminum compound was added to 100mL of wastewater and stirred at room temperature for 4 hours at 500rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rates of chloride ions were found to be 80.01% and thallium ions 99.98%, respectively.

[0067] After the reaction, the precipitate was placed in an oven and dried at 80°C, and then ground to obtain the dechlorinated / thallium product.

[0068] Comparative Example 4

[0069] Wastewater with pH=8, chloride ion concentration of 2000 mg / L, and thallium ion concentration of 300 μg / L was adjusted to pH 12 (same as in Example 3).

[0070] Five g of the calcium aluminum stone obtained in Example 4 was added to 100 mL of wastewater and stirred at room temperature for 4 hours at 500 rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rate of chloride ions by calcium aluminum stone was found to be 40.09%, and the removal rate of thallium ions was 45.63%.

[0071] The removal rate data from Example 4 and Comparative Example 4 show that the sulfur-modified calcium-aluminum compound significantly improves both chloride ion removal efficiency and thallium ion removal efficiency.

[0072] Example 5

[0073] Calcium bicarbonate and aluminum sulfate with a Ca:Al molar ratio of 1:1 were mixed and stirred evenly, and then placed in a muffle furnace and heated to 1000°C at a heating rate of 5°C / min. The mixture was held at this temperature for 5 hours, and then cooled at a cooling rate of 5°C / min. The mixture was then removed when the temperature dropped to 900°C to obtain calcium aluminum stone.

[0074] Prepare 100 mL of 5 mol / L calcium sulfide solution, add 20 g of calcium aluminum stone, heat at 50 °C and stir for 4 hours, centrifuge, dry the solid at 80 °C, and grind to obtain the modified calcium aluminum compound.

[0075] A wastewater with pH=5, a chloride ion concentration of 4000 mg / L, and a thallium ion concentration of 500 μg / L was adjusted to pH 12.

[0076] 5g of sulfur-modified calcium-aluminum compound was added to 100mL of wastewater and stirred at room temperature for 4 hours at 500rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rates of chloride ions were found to be 74.41% and thallium ions 99.65%, respectively.

[0077] After the reaction, the precipitate was placed in an oven and dried at 80°C, and then ground to obtain the dechlorinated / thallium product.

[0078] Comparative Example 5

[0079] Wastewater with pH=5, chloride ion concentration of 4000 mg / L, and thallium ion concentration of 500 μg / L was adjusted to pH 12 (same as in Example 4).

[0080] Five g of the calcium aluminum stone obtained in Example 5 was added to 100 mL of wastewater and stirred at room temperature for 4 hours at 500 rpm. The residual chloride and thallium ion contents of the liquid were measured, and the removal rate of chloride ions by calcium aluminum stone was found to be 32.62%, and the removal rate of thallium ions was 39.04%.

[0081] As can be seen from the removal rate data of Example 5 and Comparative Example 5, the sulfur-modified calcium-aluminum compound has achieved a significant improvement in both chloride ion removal efficiency and thallium ion removal efficiency.

[0082] In summary, the sulfur-modified calcium-aluminum compound provided by this invention can improve the removal efficiency of chloride and thallium ions in desulfurization wastewater. This is because sulfur modification introduces a large number of S-OH and S=O groups, increasing the active sites on the material surface and improving the adsorption performance of the material for chloride and thallium ions. Sulfur modification also introduces a negative charge, increasing the ion exchange capacity of the material surface and improving the adsorption selectivity for chloride and thallium ions. Furthermore, sulfur modification facilitates the formation of thallium sulfide precipitates, thereby improving the thallium removal rate.

[0083] Example 6

[0084] The dechlorinated / thallium-containing product obtained after removing chloride and thallium ions in Example 1 was mixed with a glass matrix raw material and a luminescent material. The glass matrix raw material was silicon dioxide and sodium oxide, and the luminescent material was a mixture of europium oxide and tellurium oxide. The mass ratio of the dechlorinated / thallium-containing product to silicon dioxide to sodium oxide to luminescent material was 30:30:15:2. After sintering at 1100°C for 2 hours, a long-afterglow luminescent microcrystalline glass capable of emitting blue light was obtained.

[0085] Example 7

[0086] The dechlorinated / thallium-containing product obtained after removing chloride and thallium ions in Example 2 was mixed with a glass matrix raw material and a luminescent material. The glass matrix raw material consisted of silicon dioxide and potassium oxide, and the luminescent material was a mixture of yttrium oxide and europium oxide. The mass ratio of the dechlorinated / thallium-containing product to silicon dioxide to sodium oxide to luminescent material was 30:50:20:5. After calcination at 1050°C for 2 hours, a long-afterglow luminescent microcrystalline glass capable of emitting red light was obtained.

[0087] Example 8

[0088] The dechlorinated / thallium-containing product obtained after removing chloride and thallium ions in Example 3 was mixed with a glass matrix raw material and a luminescent material. The glass matrix raw material was silicon dioxide and magnesium oxide, and the luminescent material was a mixture of europium oxide and neodymium oxide. The mass ratio of the dechlorinated / thallium-containing product to silicon dioxide to sodium oxide to luminescent material was 30:40:10:1. After sintering at 1080°C for 2 hours, a long-afterglow luminescent microcrystalline glass was obtained, which emitted blue-violet light.

[0089] Example 9

[0090] The dechlorinated / thallium-containing product obtained after removing chloride and thallium ions in Example 4 was mixed with a glass matrix raw material and a luminescent material. The glass matrix raw material was silicon dioxide and sodium oxide, and the luminescent material was a mixture of dysprosium oxide and europium oxide. The mass ratio of the dechlorinated / thallium-containing product to silicon dioxide to sodium oxide to luminescent material was 30:30:10:2. After calcination at 1150°C for 2 hours, a long-afterglow luminescent microcrystalline glass capable of emitting green light was obtained.

[0091] Example 10

[0092] The dechlorinated / thallium-containing product obtained after removing chloride and thallium ions in Example 5 was mixed with a glass matrix raw material and a luminescent material. The glass matrix raw material was silicon dioxide and barium oxide, and the luminescent material was a mixture of praseodymium oxide and germanium oxide. The mass ratio of the dechlorinated / thallium-containing product to silicon dioxide to sodium oxide to luminescent material was 30:30:5:5. After firing at 1200℃ for 2 hours, a long-afterglow luminescent microcrystalline glass was obtained, which could emit red light and had a melting point of 1150℃. After soaking in 10% hydrochloric acid for 10 hours, there was no obvious change on the surface of the microcrystalline glass, and the red light intensity did not decrease. After heating at 500℃ for 15 minutes and then immersing in cold water at 20℃, it was repeatedly cooled 3-5 times without cracking, and the red light intensity did not decrease significantly.

[0093] Comparative Example 2

[0094] A glass matrix material and a luminescent material were mixed. The glass matrix material consisted of silicon dioxide and sodium oxide, while the luminescent material was a mixture of praseodymium oxide and germanium oxide. The mass ratio of silicon dioxide to sodium oxide to luminescent material was 30:5:5. After firing at 1500℃ for 2 hours, a long-afterglow luminescent microcrystalline glass was obtained, which emitted blue light and had a melting point of 1400℃. Immersion in 10% hydrochloric acid for 10 hours resulted in the appearance of a small number of voids on the surface of the microcrystalline glass, and a 20% decrease in red light intensity. After heating at 500℃ for 15 minutes and then immersing in cold water at 20℃, cracks appeared a second time, and the red light intensity decreased slightly, by approximately 3.5%.

[0095] As can be seen from the data of Example 10 and Comparative Example 2, adding dechlorination / thallium products during glass firing lowers the melting point of the glass and improves its chemical stability and heat resistance.

[0096] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for removing chlorine and thallium ions from desulfurization wastewater, characterized by, The sulfur-modified calcium-aluminum compound is used as a treating agent and added into the desulfurization wastewater for stirring. The preparation method of the sulfur-modified calcium-aluminum compound comprises the following steps: The calcium source and the aluminum source are mixed and calcined to obtain the calcium-aluminum compound; then, a sulfide solution is mixed with the calcium-aluminum compound for reaction, and the product is dried and ground to obtain the sulfur-modified calcium-aluminum compound. The calcium source and the aluminum source are mixed at a Ca:Al molar ratio of (1-1.3):1; and the mass ratio of the sulfide in the sulfide solution to the calcium-aluminum compound is (0.1-2):

1.

2. The method of claim 1, wherein the method is characterized by, The calcination condition is 800-1400℃, 1-6h, and the temperature rising rate is 3-5℃ / min.

3. The method of claim 1, wherein the method is characterized by, The calcium source is one or more of calcium oxide, calcium hydroxide, calcium carbonate, carbide slag, calcium bicarbonate, and calcium nitrate. The aluminum source is one or more of aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum carbonate, aluminosilicate, and iron aluminate.

4. The method of claim 1, wherein the method is characterized by, The sulfide solution is obtained by dissolving a sulfide in water, and the concentration of the sulfide solution is 0.1-10mol / L. The sulfide is one or more of sodium sulfide, thiourea, potassium sulfide, zinc sulfide, magnesium sulfide, ferrous sulfide, manganese sulfide, calcium sulfide, and thioacetamide.

5. The method of claim 1, wherein the method is characterized by, The mixing reaction condition is 20-60℃ under stirring for 1-5h; and the drying condition is 50-110℃.

6. The method of claim 1, wherein the method is characterized by, The addition amount of the sulfur-modified calcium-aluminum compound is 0.1-200g / L, and the reaction time is 1-12h.

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