A method for treating sulfide slag

Abstract

The present invention discloses a method for treating sulfide slag, which relates to the technical field of slag treatment. The method for treating sulfide slag comprises the following steps: S10, mixing sulfide slag and water to obtain a slag-water mixture, introducing air into the slag-water mixture for aeration oxidation reaction, and obtaining an oxidized slag-water mixture; S20, adding a pH regulator to the oxidized slag-water mixture to obtain a slurry, adding an admixture to the slurry to obtain a slurry; S30, curing the slurry to obtain solidified sulfide slag; wherein the admixture includes steel slag powder, fly ash powder and slag powder. The treatment method of the present invention uses industrial solid waste as an admixture, and the sulfate radicals generated by the sulfide slag are bonded and solidified with the admixture, which significantly improves the solidification strength and long-term stability of the bond, reduces the safe treatment cost of the sulfide slag, and can be used to solve the problems of high treatment cost and poor long-term stability of the existing sulfide slag treatment method.

Description

Technical Field

[0001] The present invention relates to the technical field of slag treatment, and in particular to a method for treating sulfide slag. Background Art

[0002] Sulfide ore is a general term for a series of sulfur-containing minerals found in nature. Common sulfide ores include pyrite, chalcopyrite, bornite, lead-zinc ore, and others. They are important minerals used in the smelting of sulfur, sulfuric acid, and some non-ferrous metals. The mining and smelting processes of sulfide ore generate a series of mining rock, beneficiation tailings, and smelting waste slag. Due to their separation from the original closed reduction system and exposure to the surface oxidizing environment, the sulfur-containing components in these slags oxidize under long-term physical, chemical, and biological effects, producing sulfate-rich acid mine drainage (pH 2-5). This releases large amounts of heavy metal ions (such as Fe, Mn, Pb, and Zn), contaminating the adjacent soil and groundwater environment and seriously impacting the health and safety of people living near the mining area.

[0003] For a long time, the treatment methods for sulfide slag produced during sulfide ore mining and smelting have been pit filling or tailings pond storage. Both treatment methods require the use of materials with certain cementing activity (such as cement). The basic principle is to use the hydration products of cementing materials such as hydrated calcium silicate and ettringite to mechanically encapsulate the originally loose, fine-grained sulfide slag, thereby isolating the surrounding oxygen and water, preventing further oxidation of sulfur-containing components and releasing new pollutants. Although these treatment methods have good results, they have shortcomings in long-term effectiveness and economic efficiency. The reasons are as follows: 1) Sulfide slag, especially tailings produced by ore dressing and waste slag generated during smelting, has extremely fine particles (average particle size <40μm). Physical encapsulation and solidification requires a large amount of cementing materials, resulting in high costs. 2) The long-term effectiveness of these treatment methods is poor. Mechanical encapsulation with cementing materials does not change the original internal structure of the sulfide slag. Once the solidified body is exposed to long-term rainwater erosion and bioerosion on the surface, oxidation reactions will still occur and new pollutants will be generated. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method for treating sulfide slag, aiming to solve the problems of high treatment cost and poor long-term stability of existing sulfide slag treatment methods.

[0005] To achieve the above object, the present invention provides a method for treating sulfide slag, comprising the following steps:

[0006] mixing sulfide slag and water to obtain a slag-water mixture, introducing air into the slag-water mixture to perform an aeration oxidation reaction to obtain an oxidized slag-water mixture;

[0007] adding a pH regulator to the oxidized slag-water mixture to obtain a slurry, and adding an admixture to the slurry to obtain a slurry;

[0008] curing the slurry to obtain solidified sulfide slag;

[0009] Wherein, the admixture includes steel slag powder, fly ash powder and slag powder.

[0010] In one embodiment, the mass ratio of the sulfide slag to water is (1-5):1.

[0011] In one embodiment, in the step of introducing air into the slag-water mixture for aeration and oxidation, the total aeration rate when introducing air is 5 to 50 m 3 / t.

[0012] In one embodiment, the addition amount of the steel slag powder is 5-10% of the total mass of the slurry, the addition amount of the fly ash powder is 5-20% of the total mass of the slurry, and the addition amount of the slag powder is 5-15% of the total mass of the slurry.

[0013] In one embodiment, the calcium oxide content in the steel slag powder is greater than 35%, and the particle size of the steel slag powder is less than 80 μm; and / or,

[0014] The aluminum oxide content in the fly ash powder is greater than 15%; and / or,

[0015] The mass coefficient of the slag powder is greater than 1.2, and the particle size of the slag powder is less than 40 μm.

[0016] In one embodiment, the pH of the slurry is 7-9.

[0017] In one embodiment, the step of adding an admixture to the slurry further comprises adding water, wherein the amount of water added is 10-20% of the total mass of the slurry and the admixture.

[0018] In one embodiment, the steps of mixing sulfide slag and water to obtain a slag-water mixture, introducing air into the slag-water mixture for an aeration oxidation reaction, and obtaining an oxidized slag-water mixture include:

[0019] The sulfide slag, water and oxidant are mixed to obtain a slag-water mixture, and air is introduced into the slag-water mixture to perform an aeration oxidation reaction to obtain an oxidized slag-water mixture.

[0020] In one embodiment, the oxidant includes at least one of hydrogen peroxide, potassium permanganate and persulfate, and the added amount of the oxidant is 2-5% of the total mass of the slag-water mixture.

[0021] In one embodiment, the pH adjuster is alkaline solid waste, and the alkaline solid waste includes at least one of carbide slag, red mud slag and limestone powder.

[0022] The treatment method of sulfide slag provided by the technical solution of the present invention first oxidatively soaks the sulfide slag with water and continuously aerates the mixture to convert the slag-water mixture into an oxidized slag-water mixture. After oxidation, the sulfur-containing components in the sulfide slag are oxidized into sulfate ions; subsequently, a pH regulator is added to neutralize the acidity of the oxidized slag-water mixture, thereby promoting the hydrolysis and precipitation of heavy metal ions such as iron and manganese in the oxidized slag-water mixture, and providing an alkaline environment for subsequent hydration reactions; subsequently, an admixture containing sufficient calcium source and aluminum source is added to allow the sulfate ions and the calcium source and aluminum source in the admixture to undergo hydration reactions in an alkaline environment, thereby promoting the formation of initial hydration products, hydrated calcium silicate and hydrated calcium aluminosilicate, and the formation of important mineral ettringite, which determines the long-term stability of the consolidated body, to form a slurry to be cemented and solidified; finally, the obtained slurry is cured to achieve stable cementation and solidification of the sulfide slag. Therefore, the treatment method of the present invention is used to treat sulfide slag, which reduces the harm of the sulfur component, a potential source of pollution in sulfide slag, and effectively reduces the heavy metal leaching concentration of the sulfide slag cement, which can reduce the harm caused by direct exposure of sulfide slag. The pyrite slag treatment method provided by the present invention uses industrial solid waste as an admixture, oxidizes the sulfur-containing components in the pyrite slag into sulfate, and utilizes the self-cementing activity of sulfate to participate in the generation of calcium aluminate, thereby strengthening the chemical reaction between the cement and the cemented material, improving the curing strength and long-term stability of the cement, and thus improving the long-term stability of the sulfide slag treatment. Compared with the method of using conventional cementitious materials to treat sulfide slag, the technical solution of the present invention uses admixtures instead of cement and other cementitious materials, and the chemical bonding reaction between the admixture and the cemented material rather than a simple physical coating not only significantly improves the treatment effect of pyrite slag, but also reduces the use of cementitious materials, reuses industrial solid waste, and reduces the safe treatment cost of sulfide slag. Therefore, the technical solution of the present invention can be used to solve the problems of high treatment cost and poor long-term stability of existing sulfide slag treatment methods. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0024] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0025] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] Sulfide ore is a general term for a series of sulfur-containing minerals found in nature. Common sulfide ores include pyrite, chalcopyrite, bornite, lead-zinc ore, and others. They are important minerals used in the smelting of sulfur, sulfuric acid, and some non-ferrous metals. The mining and smelting processes of sulfide ore generate a series of mining rock, beneficiation tailings, and smelting waste slag. Due to their separation from the original closed reduction system and exposure to the surface oxidizing environment, the sulfur-containing components in these slags oxidize under long-term physical, chemical, and biological effects, producing sulfate-rich acid mine drainage (pH 2-5). This releases large amounts of heavy metal ions (such as Fe, Mn, Pb, and Zn), contaminating the adjacent soil and groundwater environment and seriously impacting the health and safety of people living near the mining area.

[0027] In view of this, the present invention proposes a method for treating sulfide slag, comprising the following steps:

[0028] mixing sulfide slag and water to obtain a slag-water mixture, introducing air into the slag-water mixture to perform an aeration oxidation reaction to obtain an oxidized slag-water mixture;

[0029] adding a pH regulator to the oxidized slag-water mixture to obtain a slurry, and adding an admixture to the slurry to obtain a slurry;

[0030] curing the slurry to obtain solidified sulfide slag;

[0031] Wherein, the admixture includes steel slag powder, fly ash powder and slag powder.

[0032] The technical solution of the present invention is to oxidatively soak the sulfide slag with water and continuously aerate the mixture to convert the slag-water mixture into an oxidized slag-water mixture. After oxidation, the sulfur-containing components in the sulfide slag are oxidized into sulfate ions, and a large amount of acidic wastewater containing sulfate ions is generated. Subsequently, a pH regulator is added to neutralize the acidity of the oxidized slag-water mixture, thereby promoting the hydrolysis and precipitation of heavy metal ions such as iron and manganese in the oxidized slag-water mixture and providing an alkaline environment for subsequent hydration reactions. Subsequently, an admixture containing sufficient calcium source and aluminum source is added to cause the sulfate ions, calcium source and aluminum source in the pyrite slag to undergo a hydration reaction in an alkaline environment, thereby promoting the formation of initial hydration products such as hydrated calcium silicate and hydrated calcium aluminosilicate, as well as the formation of an important mineral ettringite that determines the long-term stability of the consolidated body, to form a slurry to be cemented and solidified. Finally, the obtained slurry is cured to achieve stable cementation and solidification of the sulfide slag. The treatment method of the present invention is used to treat sulfide slag, which reduces the harm of sulfur components, a potential pollution source factor, effectively reduces the heavy metal leaching concentration of the sulfide slag cement, and can reduce the harm caused by direct exposure of the sulfide slag.

[0033] Conventional methods for treating sulfide slag involve directly mixing materials with a certain degree of cementitious activity (such as cement) with the sulfide slag. Hydration products of cementitious materials, such as hydrated calcium silicate and ettringite, are then used to mechanically encapsulate the loose, fine-grained sulfide slag, thereby isolating it from surrounding oxygen and water. Compared to conventional methods of treating sulfide slag with cementitious materials, the technical solution of the present invention uses industrial solid waste as an admixture, replacing cement and other cementitious materials with the admixture. The active ingredients in the admixture (primarily active calcium and active aluminum) combine with sulfate ions generated by the pyrite slag to form a framework-like ettringite, which strengthens the chemical reaction between the cementing material and the cemented material, enhancing the long-term solidification strength and durability of the consolidated body, thereby improving the long-term stability of the sulfide slag treatment. Moreover, the technical solution of the present invention significantly improves the treatment effect of pyrite slag by chemically combining the admixture with the cemented material rather than simply physically coating it. It not only reduces the treatment cost, but also can efficiently solidify and stabilize the heavy metals in the sulfide slag, reducing the stacking of waste such as steel slag, fly ash and slag.

[0034] In an embodiment of the present invention, the mass ratio of the sulfide slag to water is (1-5): 1. Setting the mass ratio of the sulfide slag to water to (1-5): 1 is conducive to controlling the moisture content of the sulfide slag and fully oxidizing the sulfur components of the sulfide slag to sulfate.

[0035] In the embodiment of the present invention, in the step of introducing air into the slag-water mixture for aeration and oxidation reaction, the total aeration rate when introducing air is 5 to 50 m 3The aeration rate of the air introduced is controlled within the above range to fully oxidize the sulfur-containing components in the sulfide slag into sulfate radicals, thereby increasing the self-cementing activity of the sulfate radicals.

[0036] In an embodiment of the present invention, the amount of steel slag powder added is 5-10% of the total mass of the slurry, the amount of fly ash powder added is 5-20% of the total mass of the slurry, and the amount of slag powder added is 5-15% of the total mass of the slurry. Setting the amounts of steel slag powder, fly ash powder, and slag powder within the above ranges can provide sufficient calcium and aluminum sources, promote the formation of initial hydration products such as hydrated calcium silicate and hydrated calcium aluminosilicate, and the formation of a later hydration product, framework ettringite, thereby improving the solidification strength and long-term stability of the sulfide slag.

[0037] In an embodiment of the present invention, the steel slag powder has a calcium oxide content greater than 35%, and a particle size less than 80 μm. Using steel slag powder with a calcium oxide (CaO) content greater than 35% and a particle size less than 80 μm helps increase the reactivity of the steel slag particles and fully release the active calcium, magnesium, and aluminum components therein.

[0038] In an embodiment of the present invention, the aluminum oxide content in the fly ash powder is greater than 15%. Selecting fly ash powder with an aluminum oxide (Al2O3) content greater than 15% is conducive to providing sufficient aluminum source.

[0039] In an embodiment of the present invention, the mass coefficient of the slag powder is greater than 1.2, and the particle size of the slag powder is less than 40 μm. The mass coefficient K of the slag powder = (CaO + MgO + Al2O3) / (SiO2 + MnO + TiO2). The mass coefficient K can be used to quantify the reactivity of slag powder under specific conditions, that is, the ability of slag powder to react with calcium hydroxide (Ca(OH)2) in cement hydration products to generate substances such as calcium silicate hydrate (CSH) with gelling properties. Setting the activity coefficient K of the slag powder to be greater than 1.2 and the particle size to be less than 40 μm can fully guarantee the reactivity of the slag powder.

[0040] In an embodiment of the present invention, the pH value of the slurry is 7 to 9. When the pH value of the slurry is 7 to 9, it is conducive to the hydration reaction between sulfate and the calcium source and aluminum source in the admixture, promoting the formation of initial hydration products such as hydrated calcium silicate and hydrated calcium aluminosilicate, as well as the formation of ettringite, which determines the long-term stability of the consolidated body.

[0041] In an embodiment of the present invention, the step of adding an admixture to the slurry further comprises adding water, wherein the amount of water added is 10-20% of the total mass of the slurry and the admixture. During the mixing of the slurry and the admixture, water is sprayed regularly for moisture retention to promote the hydration reaction.

[0042] In an embodiment of the present invention, the steps of mixing sulfide slag and water to obtain a slag-water mixture, introducing air into the slag-water mixture to perform an aeration oxidation reaction, and obtaining an oxidized slag-water mixture include:

[0043] The sulfide slag, water and oxidant are mixed to obtain a slag-water mixture, and air is introduced into the slag-water mixture to perform an aeration oxidation reaction to obtain an oxidized slag-water mixture.

[0044] In addition to continuous aeration, adding a certain amount of oxidant can accelerate the rapid oxidation of sulfur-containing components and shorten the treatment time.

[0045] In an embodiment of the present invention, the oxidant comprises at least one of hydrogen peroxide, potassium permanganate, and persulfate, and the amount of the oxidant added is 2-5% of the total mass of the slag-water mixture. The fact that the oxidant comprises at least one of hydrogen peroxide, potassium permanganate, and persulfate means that the oxidant can be any one of hydrogen peroxide, potassium permanganate, and persulfate, or two or more of these, all falling within the scope of protection of the present invention. The amount of the oxidant added is 2-5% of the total mass of the slag-water mixture. Within this range, the amount of the oxidant added can be 2%, 3%, 4%, and 5% of the total mass of the slag-water mixture.

[0046] In an embodiment of the present invention, the pH regulator is alkaline solid waste, which includes at least one of carbide slag, red mud slag, and limestone powder. The alkaline solid waste can be any one of carbide slag, red mud slag, and limestone powder, or two or more of these, all of which fall within the scope of protection of the present invention. In the technical solution of the present invention, the alkaline solid waste not only provides alkalinity, but also provides sufficient silicon and aluminum sources. Therefore, using alkaline solid waste as a pH regulator can fully neutralize H in the slag-water mixture. + , preventing acidity from corroding the subsequent solidified body, while promoting the hydrolysis and precipitation of heavy metal ions such as iron and manganese, providing a good medium environment for the subsequent generation of hydration products, and providing silicon and aluminum sources to facilitate the formation of ettringite. It should be noted that grinding the alkaline solid waste to a particle size of less than 40 μm before use facilitates the rapid progress of the hydration reaction.

[0047] In the embodiment of the present invention, there is no restriction on the curing method of the slurry, and the slurry can be cured according to conventional curing technology until it meets the standards.

[0048] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0049] The pyrite slag samples used in the various embodiments of the present invention are the same, and their main chemical components are shown in Table 1.

[0050] Table 1 Main chemical components of pyrite slag

[0051] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[K2O]]> <![CDATA[SO3]]> MgO <![CDATA[TiO2]]> CaO <![CDATA[P2O5]]> content 51.17％ 24.13％ 8.82％ 7.11％ 3.15％ 2.26％ 2.18％ 0.63％ 0.45％

[0052] Example 1

[0053] A method for treating sulfide slag comprises the following steps:

[0054] (1) Add 20 kg of tap water to 50 kg of pyrite slag (average particle size of 40 μm) for elution to form a slag-water mixture, and aerate the slag-water mixture at an aeration rate of 10 m 3 / t. Hydrogen peroxide was added during the leaching process (the amount added was 2% of the total mass of the slag-water mixture). When the pH value of the leaching solution showed no significant change within 2 hours, the leaching and aeration operations were stopped, and the leaching solution and oxidized sulfide slag were collected to obtain the oxidized slag-water mixture.

[0055] (2) mixing the oxidized slag-water mixture and alkaline red mud powder with a particle size of 40 μm (the addition amount is 10% of the mass of the oxidized slag-water mixture) in a blender to obtain a slurry, and then adding steel slag powder (particle size of 35 μm, CaO content of 45%), 5% of the total mass of the slurry, fly ash powder (particle size of 10 μm, Al2O3 content of 22%), and 8% of the total mass of the slurry (particle size of 30 μm, activity coefficient K = 1.5) to obtain a slurry. During the stirring process, water (10% of the total mass of the above mixture) is added to moisturize the mixture to obtain a slurry;

[0056] (3) The fully stirred slurry was transferred to a mold for compression molding and cured for 5 days. The heavy metal leaching concentration, compressive strength, and permeability coefficient of the solidified body were tested in a weakly acidic environment according to the "Solid Waste Leaching Toxicity Method—Sulfuric Acid and Nitric Acid Method" (HJ / T299-2007). The test results are shown in Table 2.

[0057] Table 2 Performance test results of Example 1

[0058] category Fe Mn Pb Zn Compressive strength Permeability coefficient result 7.5 μg / L 3.6 μg / L 2.8 μg / L 3.2 μg / L 3.6MPa <![CDATA[6.8×10 -8 cm / s]]>

[0059] Example 2

[0060] Compared with Example 1, the difference is that in step (2), the amount of steel slag powder added is 10% of the total mass of the slurry; the amount of fly ash powder added is 20% of the total mass of the slurry; the amount of slag powder added is 15% of the total mass of the slurry; and the amount of water added is 20% of the total mass of the slurry and the admixture.

[0061] The test results of heavy metal leaching concentration, compressive strength and permeability coefficient of the consolidated body are shown in Table 3.

[0062] Table 3 Performance test results of Example 2

[0063] category Fe Mn Pb Zn Compressive strength Permeability coefficient result 5.8 μg / L 1.2 μg / L 0μg / L 0μg / L 4.8MPa <![CDATA[2.6×10 -8 cm / s]]>

[0064] Example 3

[0065] Compared with Example 1, the difference is that hydrogen peroxide is not added in step (1);

[0066] In step (2), the amount of steel slag powder added is 5% of the total mass of the slurry; the amount of fly ash powder added is 10% of the total mass of the slurry; the amount of slag powder added is 8% of the total mass of the slurry; and the amount of water added is 10% of the total mass of the slurry and admixtures.

[0067] The test results of heavy metal leaching concentration, compressive strength and permeability coefficient of the consolidated body are shown in Table 4.

[0068] Table 4 Performance test results of Example 3

[0069] category Fe Mn Pb Zn Compressive strength Permeability coefficient result 11.6 μg / L 4.8 μg / L 3.9 μg / L 6.2 μg / L 2.6MPa <![CDATA[8.2×10 -8 cm / s]]>

[0070] Comparative Example 1

[0071] Portland cement and pyrite tailings powder were mixed in a mass ratio of 1:2 to obtain a mixture, water (40% of the total mass of the mixture) was added to the mixture and stirred to obtain a slurry, and the slurry was placed in a mold for compression molding and cured for 5 days.

[0072] The test results of heavy metal leaching concentration, compressive strength and permeability coefficient of the consolidated body are shown in Table 5.

[0073] Table 5 Performance test results of comparative example 1

[0074] category Fe Mn Pb Zn Compressive strength Permeability coefficient result 68.2 μg / L 18.2 μg / L 10.9 μg / L 12.7 μg / L 1.2MPa <![CDATA[8.6×10 -7 cm / s]]>

[0075] Comparative Example 2

[0076] A general-purpose cementitious material and sulfide slag were mixed in a mass ratio of 1:2 to form a mixture; the general-purpose cementitious material's basic components included fly ash, slag, steel slag, water glass, a water reducer, and a small amount of cement. Water (40% of the total mass of the mixture) was added to the mixture and stirred to form a slurry. The slurry was then pressed into a mold and cured for 5 days.

[0077] The test results of heavy metal leaching concentration, compressive strength and permeability coefficient of the consolidated body are shown in Table 6.

[0078] Table 6 Performance test results of comparative example 2

[0079] category Fe Mn Pb Zn Compressive strength Permeability coefficient result 36.7 μg / L 18.2 μg / L 12.7 μg / L 17.5 μg / L 2.5Mpa <![CDATA[2.8×10 -7 cm / s]]>

[0080] From the above test results, it can be seen that under the same material dosage and curing time, the treatment methods of Example 1 and Example 3 can achieve a certain solidification and stabilization effect on pyrite slag, but the heavy metal solidification effect and anti-penetration ability of ordinary Portland cement (Comparative Example 1) and universal cementitious material (Comparative Example 2) are worse than those of Example 1 and Example 3. This is because the solidification and stabilization of traditional cement and cementitious material are mechanical coatings, which do not change the internal structure of the solidified body, resulting in the cement solidified body and the cementitious material solidified body being more susceptible to erosion and damage in an acidic leaching environment, releasing more heavy metal ions, while the treatment methods of Example 1 and Example 3 form a denser self-cementing structure by stimulating the gelling activity of the pyrite slag itself, and are more stable under long-term weathering and erosion. The comparative results of Example 1, Example 2, and Example 3 show that the solidification and stabilization effect of pyrite slag can be further improved by adding oxidizing agents to assist impregnation and increasing the amount of admixtures.

[0081] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by utilizing the contents of the present invention specification under the technical concept of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A method for treating sulfide slag, characterized in that: The following steps are involved: mixing sulfide slag and water to obtain a slag-water mixture, introducing air into the slag-water mixture to perform an aeration oxidation reaction to obtain an oxidized slag-water mixture; adding a pH regulator to the oxidized slag-water mixture to obtain a slurry, and adding an admixture to the slurry to obtain a slurry; curing the slurry to obtain solidified sulfide slag; Wherein, the admixture includes steel slag powder, fly ash powder and slag powder.

2. The method for treating sulfide slag according to claim 1, wherein: The mass ratio of the sulfide slag to water is (1-5):

1.

3. The method for treating sulfide slag according to claim 1, wherein: In the step of introducing air into the slag-water mixture for aeration and oxidation reaction, the total aeration volume when introducing air is 5 to 50 m 3 / t.

4. The method for treating sulfide slag according to claim 1, wherein: The added amount of the steel slag powder is 5-10% of the total mass of the slurry, the added amount of the fly ash powder is 5-20% of the total mass of the slurry, and the added amount of the slag powder is 5-15% of the total mass of the slurry.

5. The method for treating sulfide slag according to claim 1, wherein: The calcium oxide content in the steel slag powder is greater than 35%, and the particle size of the steel slag powder is less than 80 μm; and / or, The aluminum oxide content in the fly ash powder is greater than 15%; and / or, The mass coefficient of the slag powder is greater than 1.2, and the particle size of the slag powder is less than 40 μm.

6. The method for treating sulfide slag according to claim 1, wherein: The pH value of the slurry is 7-9.

7. The method for treating sulfide slag according to claim 1, wherein: The step of adding admixture to the slurry further comprises adding water, wherein the amount of water added is 10-20% of the total mass of the slurry and the admixture.

8. The method for treating sulfide slag according to claim 1, wherein: The steps of mixing sulfide slag and water to obtain a slag-water mixture, introducing air into the slag-water mixture for an aeration oxidation reaction to obtain an oxidized slag-water mixture include: The sulfide slag, water and oxidant are mixed to obtain a slag-water mixture, and air is introduced into the slag-water mixture to perform an aeration oxidation reaction to obtain an oxidized slag-water mixture.

9. The method for treating sulfide slag according to claim 8, wherein: The oxidant includes at least one of hydrogen peroxide, potassium permanganate and persulfate, and the added amount of the oxidant is 2-5% of the total mass of the slag-water mixture.

10. The method for treating sulfide slag according to claim 1, wherein: The pH regulator is alkaline solid waste, and the alkaline solid waste includes at least one of carbide slag, red mud slag and limestone powder.