Method for preparing solid waste cementing material from micro-carbonized steel slag

Abstract

The invention discloses a method for preparing a solid waste cementing material from micro-carbonized steel slag, and belongs to the technical field of building materials. The preparation method comprises the following steps: carrying out crushing, iron separation and grinding treatment on steel slag particles to obtain steel slag powder; mixing the steel slag powder with water and a carbonization aid to obtain a steel slag wet mixture; feeding the wet steel slag mixture into a carbon dioxide curing kettle for curing and intensely stirring, quickly carbonizing to obtain micro-carbonized steel slag particles, and grinding and drying to obtain micro-carbonized steel slag powder; 45-70 parts of micro-carbonized steel slag, 15-35 parts of slag, 1-8 parts of gypsum, 1-8 parts of cement or clinker, 1-15 parts of fly ash or metal tailings, 1-10 parts of an alkaline solution and 25-30 parts of water are mixed to obtain the micro-carbonized steel slag solid waste cementing material. The micro-carbonized solid waste steel slag cementing material prepared by the invention has the advantages of low cost, simple preparation process and equipment, better early and later mechanical properties, good stability, low carbon, high additional value and the like.

Description

Technical Field

[0001] The invention belongs to resource utilization of solid waste building materials, and specifically relates to a method for preparing solid waste cementitious materials by using micro-carbonized steel slag. Background Art

[0002] Steel slag is an industrial byproduct produced during the steelmaking process, and its emission accounts for about 10% to 16% of crude steel production. my country's steel slag has the characteristics of large production, high stockpiling, and low comprehensive utilization. The long-term stacking and disposal of steel slag not only occupies a large area of ​​land, but also the heavy metal ions precipitated from the steel slag will pollute the land and damage the soil, and will also cause water pollution after seeping into groundwater.

[0003] The main chemical components of steel slag usually include CaO, Fe x O, SiO2 and Al2O3, etc. The main low-activity phase in steel slag is γ-C2S, which has extremely low hydration activity. Free CaO, free MgO, Ca(OH)2 and Mg(OH)2 in steel slag can undergo carbonization reaction to generate calcium carbonate or magnesium carbonate, and C3S, CaSiO3, β-C2S and γ-C2S can be carbonized to generate amorphous SiO2, which is beneficial to the improvement of steel slag stability and activity.

[0004] At present, carbonized steel slag has been used to prepare aggregates and carbonized steel slag products. Nano-CaCO3 crystals grow and interweave in carbonized steel slag, which can make carbonized steel slag have higher particle strength. Aggregates and bricks prepared from carbonized steel slag can have higher carbon fixation rate and compressive strength.

[0005] On the other hand, carbonized steel slag can be used to prepare admixtures and cementitious materials. CO2 reacts with calcium silicate in steel slag to generate CaCO3 and amorphous SiO2. Amorphous SiO2 has potential chemical activity. When carbonized steel slag is used as a cement admixture, amorphous SiO2 undergoes hydration reaction to generate hydrated calcium silicate, which helps to promote hydration reaction and strengthen the interface of cement matrix, thus improving the mechanical properties of cementitious materials.

[0006] However, carbonized steel slag used as a mixing material usually requires a higher activity index, and has higher requirements on the carbonization process, steel slag carbonization depth and carbonization efficiency. Summary of the invention

[0007] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for preparing solid waste cementitious materials from micro-carbonized steel slag in view of the shortcomings of the prior art. The method has the characteristics of high mechanical properties, low carbon and high added value, which is beneficial to promoting the consumption and utilization of CO2 and the resource utilization of steel slag solid waste.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for preparing solid waste cementitious materials from micro-carbonized steel slag comprises the following steps: Step (1): crushing, iron selection and grinding the steel slag particles to obtain steel slag powder, and drying after powder selection; The steel slag particles are mainly three types of steel slag, which are any one or a combination of two or more of electric furnace slag, open-hearth furnace slag and converter slag.

[0009] Furthermore, the steel slag particles are crushed by a crusher, and then the iron blocks in the steel slag particles are removed by magnetic separation using an iron remover. The steel slag particles are then sent to a ball mill for grinding to 200-300 meshes to obtain steel slag powder, which is then dried at 100-105°C for more than 24 hours.

[0010] Furthermore, the grinding aid is selected from any one or a combination of two or more of triethanolamine, ethylene glycol, sodium silicate, sodium tripolyphosphate, and sodium polyphosphate; the mass ratio of the grinding aid to the steel slag powder is 0.01-0.05:100.

[0011] Step (2): the steel slag powder and water in step (1) are mixed according to the following weight proportions: 100 parts of steel slag powder, 0.1-10 parts of water, and 1-10 parts of a carbonization aid, to obtain a steel slag wet mix.

[0012] Wherein, the water comes from tap water or purified water.

[0013] The carbonization aid is any one of dilute hydrochloric acid, dilute sulfuric acid, and dilute nitric acid, or a combination of two or more thereof, with a concentration of 0.01-0.1 mol / L.

[0014] Step (3), sending the steel slag wet mixture in step (2) to a carbon dioxide curing kettle, introducing CO2 gas, and causing the steel slag powder to undergo a carbonization reaction with CO2 under CO2 curing conditions to obtain carbonized steel slag particles.

[0015] Among them, the CO2 concentration is 30~99%, and the CO2 gas introduced is preferably above 50%.

[0016] The CO2 curing conditions are a temperature of 20-60°C, a CO2 partial pressure of 0.1-0.5 MPa, and a time of 3-45 minutes, preferably 60°C, 0.1 MPa, and 30 minutes.

[0017] Specifically, the carburized steel slag is ball-milled by a planetary ball mill, and then passed through a 74 μm square hole sieve to obtain the carburized steel slag powder, which is then dried at 100-105° C. for more than 24 hours.

[0018] Step (4), preparing a solid waste gelling material according to the following components in parts by weight: Micro-carbonized steel slag: 45~70 parts; Slag: 15~35 parts; Gypsum: 1~8 parts; Cement or clinker: 1~8 parts; Fly ash or metal tailings: 1~15 parts Alkaline solution: 1~10 parts; Water: 25-30 parts; The raw materials of each component are weighed, stirred, poured and molded according to the above ratio to obtain the product.

[0019] Preferably, it is composed of the following components in parts by mass: Carbonized steel slag powder: 50~60 parts; Slag: 25~35 parts; Gypsum: 1-5 parts; Cement or clinker: 1~5 parts; Fly ash or metal tailings: 5~15 parts Alkaline solution: 1~5 parts; Water: 25-28 parts; Preferably, the micro-carbonized steel slag is the micro-carbonized steel slag powder obtained in step (3); the gypsum is one or a combination of two or more of phosphogypsum, fluorgypsum, and desulfurized gypsum; the cement or clinker is silicate cement or clinker; the fly ash is primary, secondary or tertiary fly ash; the metal tailings is any one of iron tailings, copper tailings, aluminum tailings, and zinc tailings; and the specific surface area of ​​the fly ash or metal tailings powder is 300-450m 2 / g; the alkaline solution is one or a combination of two or more of sodium hydroxide and potassium hydroxide, and the concentration of the alkaline solution is 1~5mol / L.

[0020] Compared with the prior art, the present invention has the following beneficial effects: First, the present invention firstly adopts rapid (3 to 45 minutes), normal / low pressure (0.1 to 0.5 MPa) CO2 carbonization of steel slag, so that the steel slag is slightly carbonized and has a low degree of carbonization (3% to 10%); on the one hand, CO2 reacts with free calcium oxide and magnesium oxide in the steel slag to absorb free calcium oxide and magnesium oxide, thereby improving the stability of the steel slag; on the other hand, CO2 reacts with part of the calcium silicate (γ-C2S) in the steel slag to generate nano-calcium carbonate and amorphous silicon dioxide, thereby improving the reaction activity of the steel slag, and contributing to the early performance development of the carbonized steel slag cementitious material, while retaining part of the silicate (γ-C2S) mineral phase, contributing to the continuous development of the later performance of the carbonized steel slag solid waste cementitious material.

[0021] Second: In the process of micro-carbonizing steel slag in the present invention, the carbonization aids dilute sulfuric acid, dilute hydrochloric acid and dilute nitric acid will react with the calcium component in the steel slag to generate calcium sulfate (CaSO4), calcium chloride (CaCl2) and calcium nitrate (Ca(NO3)2). Calcium sulfate can play an exciting role and react with the active Al2O3 in the slag to generate hydrated calcium sulfoaluminate (AFt or AFm) (Equations (1) and (2)). Calcium chloride will also react with the active Al2O3 in the slag to generate hydrated calcium chloroaluminate (Equation (3)), playing the role of "synergistic activation" of micro-carbonized steel slag and slag. At the same time, due to the formation of calcium sulfate in the micro-carbonized steel slag, the gypsum content in the present invention is reduced.

[0022] Al2O3+3CaSO4+3Ca(OH)2+29H2O→3CaO∙Al2O3∙3CaSO4∙32H2O (AFt) (1) Al2O3+CaSO4+3Ca(OH)2+9H2O→3CaO∙Al2O3∙CaSO4∙12H2O (AFm) (2) Al2O3+3CaCl2+3Ca(OH)2+7H2O→3CaO∙Al2O3∙3CaCl2∙10H2O (3).

[0023] Third, the present invention uses alkaline solutions of potassium hydroxide and sodium hydroxide to provide an alkaline hydration environment in the early stage of the micro-carbonized steel slag solid waste cementitious material, promote the hydration reaction of amorphous SiO2, a carbonized product in the micro-carbonized steel slag, and active SiO2 in the slag, generate hydrated calcium silicate, and promote the development of early mechanical properties of the micro-carbonized steel slag solid waste cementitious material. At the same time, the present invention uses a small amount of silicate cement or clinker, and the early hydration product calcium hydroxide will also provide an alkaline environment for the micro-carbonized steel slag solid waste cementitious system, promote the hydration reaction of active SiO2, and promote early performance development.

[0024] Fourth: The present invention uses micro-carbonized steel slag to prepare solid waste cementitious materials, constructs a CaO-SiO2-Al2O3-SO3-CO2 cementitious system, and has high early strength and late strength, low volume expansion rate, and good stability. The nano calcium carbonate generated by the carbonization reaction of steel slag can partially participate in the hydration reaction to generate hydrated calcium aluminate (Hc and Mc) (Equations (4 and 5)), and partially fill in the pores and matrix of the solid waste cementitious materials to increase the density of the matrix and improve the mechanical properties; the nano SiO2 generated by the carbonization reaction has high activity and fast hydration reaction rate, and participates in the hydration reaction in the early stage to generate hydrated calcium silicate (Equation (6)), which promotes the development of the early performance of the carbonized steel slag solid waste cementitious materials; the hydration rate of γ-C2S in the carbonized steel slag is relatively slow, and it participates in the hydration reaction in the later stage to generate hydrated calcium silicate and calcium hydroxide (Equation (7)), which promotes the development of the later performance.

[0025] 3CaO∙Al2O3+CaCO3+11H2O→4CaO∙Al2O3∙CO2∙11H2O (Mc) (4) 3CaO∙Al2O3+0.5CaCO3+0.5Ca(OH)2+11.5H2O→4CaO∙Al2O3∙(CO2) 0.5 ∙12H2O (Hc) (5) xSiO2+ Ca(OH)2+ (y-1)H2O→CaO∙xSiO2∙yH2O (6) xγ-C2S+(y+1)H2O→CaO∙xSiO2∙yH2O+ Ca(OH)2 (7).

[0026] Fifth, the carbonization process of the present invention has relatively low requirements, and a low-pressure (0.1-0.5MPa), low-concentration (50%-99%), and relatively low-temperature (20-60°C) carbonization process can be adopted, thereby allowing the use of industrial tail gas CO2, and the carbonization process is easy to implement.

[0027] Sixth, the total amount of micro-carbonized steel slag and slag in the micro-carbonized steel slag solid waste cementitious material of the present invention is greater than 75%, and it has good early and late activity. It can be mixed with part of fly ash and low-activity metal tailings including iron tailings, copper tailings, aluminum tailings, zinc tailings, etc., which is beneficial to the resource utilization of metal tailings.

[0028] Seventh, the micro-carbonized steel slag solid waste cementitious material of the present invention has the characteristics of low carbon, low cost and high added value. On the one hand, the present invention adopts CO2 carbonized steel slag powder, which promotes the resource utilization of carbon dioxide in the field of building materials and has negative carbon properties; on the other hand, it adopts a large amount of solid waste (little / no cement or clinker) to prepare cementitious materials, so that the carbonized steel slag solid waste cementitious material has low carbon emissions and low carbon properties; the micro-carbonized steel slag solid waste cementitious material can be used as roadbed materials and for the preparation of building materials and products, and has high added value; at the same time, it is conducive to promoting the resource utilization and sustainable utilization of industrial solid waste steel slag, reducing its pollution to the environment and reducing the pressure on the ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0030] Figure 1 The present invention is a flow chart for preparing the carbonized steel slag solid waste cementitious material. DETAILED DESCRIPTION

[0031] The present invention can be better understood with reference to the following examples. Comparative Example 1

[0032] A method for preparing solid waste cementitious material using uncarbonized steel slag comprises the following steps: (1) Crushing, iron separation and grinding the steel slag particles to obtain steel slag powder; (2) The raw material composition of steel slag solid waste cementitious materials is as follows: Steel slag powder (uncarbonized): 40 parts; slag: 30 parts; gypsum: 15 parts; cement: 15 parts; all raw materials are fully mixed; (3) Add 30 parts of water to the mixture in step (2); (4) Then stir in a cement slurry mixer for 3 to 4 minutes; (5) Pour the stirred slurry into the mold and compact it on a cement mortar compaction table for 30 to 45 seconds; (6) The mold is left to stand for 1 day to form; the molded sample is demolded and subjected to standard curing until a specific age. Example 1

[0033] Combination Figure 1 The method for preparing solid waste cementitious material from micro-carbonized steel slag of the present invention comprises the following steps: (1) Crushing, iron separation and grinding the steel slag particles to obtain steel slag powder; (2) mixing the steel slag powder and water in step (1) according to the weight ratio: 100 parts of steel slag powder and 10 parts of water to obtain a steel slag wet mix; (3) sending the wet mixed steel slag material from step (2) to a carbon dioxide curing kettle, introducing 50% CO2 gas, and carbonizing at 60°C and 0.1 MPa carbonization pressure for 30 minutes to obtain carbonized steel slag particles, which are then ground and dried to obtain carbonized steel slag powder; (4) The raw material composition of the carbonized steel slag solid waste cementitious material is as follows: slightly carbonized steel slag: 40 parts; slag: 30 parts; gypsum: 15 parts; cement or clinker: 15 parts; water: 30 parts; all raw materials are fully mixed; (5) Then stir in a cement slurry mixer for 3 to 4 minutes; (6) Pour the stirred slurry into the mold and compact it on a cement mortar compaction table for 30 to 45 seconds; (7) The mold is left to stand for 1 day to form; the molded sample is demolded and subjected to standard curing. Example 2

[0034] A method for preparing solid waste cementitious materials from micro-carbonized steel slag comprises the following steps: (1) Crushing, iron separation and grinding the steel slag particles to obtain steel slag powder; (2) The steel slag powder and water in step (1) are mixed according to the following weight proportions: 100 parts of steel slag powder, 5 parts of water, and 5 parts of carbonization aid to obtain a steel slag wet mix; (3) sending the wet mixed steel slag from step (2) to a carbon dioxide curing kettle, introducing 50% CO2 gas, carbonizing at 60°C and 0.1 MPa carbonization pressure to obtain carbonized steel slag particles, and grinding and drying to obtain carbonized steel slag powder; (4) The raw material composition of carbonized steel slag solid waste cementitious material is as follows: slightly carbonized steel slag: 50 parts; slag: 30 parts; gypsum: 5 parts; cement or clinker: 5 parts; fly ash or metal tailings: 10 parts; potassium hydroxide alkaline solution: 5 parts; water: 25 parts; (5) Then stir in a cement slurry mixer for 3 to 4 minutes; (6) Pour the stirred slurry into the mold and compact it on a cement mortar compaction table for 30 to 45 seconds; (7) The mold is left to stand for 1 day to form; the molded sample is demolded and subjected to standard curing. Example 3

[0035] A method for preparing solid waste cementitious materials from micro-carbonized steel slag comprises the following steps: (1) Crushing, iron separation and grinding the steel slag particles to obtain steel slag powder; (2) The steel slag powder and water in step (1) are mixed according to the following weight proportions: 100 parts of steel slag powder, 5 parts of water, and 5 parts of carbonization aid to obtain a steel slag wet mix; (3) sending the wet mixed steel slag from step (2) to a carbon dioxide curing kettle, introducing 50% CO2 gas, carbonizing at 60°C and 0.1 MPa carbonization pressure to obtain carbonized steel slag particles, and grinding and drying to obtain carbonized steel slag powder; (4) The raw material composition of carbonized steel slag solid waste cementitious material is as follows: slightly carbonized steel slag: 55 parts; slag: 25 parts; gypsum: 5 parts; cement or clinker: 5 parts; fly ash or metal tailings: 10 parts; potassium hydroxide alkaline solution: 5 parts; water: 25 parts; (5) Then stir in a cement slurry mixer for 3 to 4 minutes; (6) Pour the stirred slurry into the mold and compact it on a cement mortar compaction table for 30 to 45 seconds; (7) The mold is left to stand for 1 day to form; the molded sample is demolded and subjected to standard curing. Example 4

[0036] A method for preparing solid waste cementitious materials from micro-carbonized steel slag comprises the following steps: (1) Crushing, iron separation and grinding the steel slag particles to obtain steel slag powder; (2) The steel slag powder and water in step (1) are mixed according to the following weight proportions: 100 parts of steel slag powder, 5 parts of water, and 5 parts of carbonization aid to obtain a steel slag wet mix; (3) sending the wet mixed steel slag from step (2) to a carbon dioxide curing kettle, introducing 50% CO2 gas, carbonizing at 60°C and 0.1 MPa carbonization pressure to obtain carbonized steel slag particles, and grinding and drying to obtain carbonized steel slag powder; (4) The raw material composition of carbonized steel slag solid waste cementitious material is as follows: slightly carbonized steel slag: 60 parts; slag: 25 parts; gypsum: 5 parts; fly ash or metal tailings: 10 parts; potassium hydroxide alkaline solution: 5 parts; water: 25 parts; (5) Then stir in a cement slurry mixer for 3 to 4 minutes; (6) Pour the stirred slurry into the mold and compact it on a cement mortar compaction table for 30 to 45 seconds; (7) The mold is left to stand for 1 day to form; the molded sample is demolded and subjected to standard curing.

[0037] The carbonization degree of the steel slag in the above-mentioned comparative example 1 and embodiments 1-4 is shown in the following table.

[0038] Table 1 Carbonization degree of steel slag in comparative example 1 and examples 1-4 (%)

[0039] The proportions of the solid waste cementitious materials in Comparative Example 1 and Examples 1-4 are shown in the following table.

[0040] Table 2 Comparative Examples and Example Proportions (wt.%)

[0041] The setting time, strength and 28d expansion rate of the solid waste cementitious materials of Comparative Example 1 and Examples 1-4 are as follows.

[0042] Table 3 Setting time, strength, expansion rate and stability of solid waste cementitious materials in comparative examples and examples

[0043] As shown in Table 1, the carbonization degree of steel slag is calculated based on the carbonization weight gain rate of steel slag. The weight gain rate of carbonized steel slag is basically around 4%, the CaO involved in the reaction is about 5%, and the formation of calcium carbonate is basically around 10%. The free calcium oxide content in the steel slag of Examples 1-4 is less than that of Comparative Example 1.

[0044] Compared with the XRD of Comparative Example 1, the diffraction peak of calcium carbonate appeared in Example 1, and the peaks of calcium hydroxide, free calcium oxide and free magnesium oxide were all reduced, mainly because CO2 reacted with free calcium oxide and magnesium oxide in the steel slag, absorbing part of the free calcium oxide and magnesium oxide. At the same time, a relatively high C2S diffraction peak was retained in Example 1, which was helpful to promote the development of the later mechanical properties of the solid waste cementitious material.

[0045] As can be seen from Table 3, the initial setting time of Examples 1-4 is greater than 45 minutes, and the final setting time is less than 10 hours. The early and late compressive strengths of Examples 1-4 are greater than those of Comparative Example 1, mainly because the steel slag in this patent forms amorphous SiO2 after carbonization, which improves the early activity, and the alkaline solution plays an stimulating role, promoting the development of early strength. At the same time, a certain amount of C2S is retained in the carbonized steel slag, which continues to hydrate in the later stage to promote the development of late strength. Compared with Comparative Example 1, the expansion rate of Examples 1-4 is significantly reduced, mainly because the free CaO and free MgO in the steel slag undergo carbonization reaction to generate calcium carbonate and magnesium carbonate, which improves volume stability and stability.

[0046] The present invention provides a method for preparing solid waste cementitious materials from micro-carbonized steel slag. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A method for preparing solid waste cementitious materials from micro-carbonized steel slag, characterized in that: The steps include: (1) Crushing the steel slag particles, selecting iron, adding grinding aids to grind them to obtain steel slag powder, and drying them after powder selection; (2) mixing the steel slag powder obtained in step (1) with water and a carbonization aid to obtain a steel slag wet mix; (3) sending the wet mixed steel slag material from step (2) to a carbon dioxide curing kettle, introducing CO2 gas and fully stirring the mixture to allow the steel slag to undergo a rapid carbonization reaction with CO2 to obtain slightly carbonized steel slag particles, which are then ground to obtain slightly carbonized steel slag powder; (4) Prepare solid waste cementitious materials according to the following components in parts by weight: Micro-carbonized steel slag powder: 45~70 parts; Slag: 15~35 parts; Gypsum: 1~8 parts; Cement or clinker: 1~8 parts; Fly ash or metal tailings: 1~15 parts; Alkaline solution: 1~10 parts; Water: 25-30 parts; The raw materials of each component are weighed, stirred, poured and molded according to the above ratio to obtain the product.

2. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (1), the slag particles are selected from any one of electric furnace slag, open-hearth furnace slag, and converter slag, or a combination of two or more thereof; the slag particles are crushed by a crusher, and then the iron blocks in the slag particles are removed by magnetic separation using an iron remover, and then the slag particles are sent to a ball mill and a grinding aid is added to grind the slag particles to a specific surface area of ​​300 to 400 m 2 / g, and obtain steel slag powder, which is then dried at 100-105°C for more than 24 hours.

3. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (1), the grinding aid is selected from any one of triethanolamine, ethylene glycol, sodium silicate, sodium tripolyphosphate, sodium polyphosphate, or a combination of two or more thereof; the grinding aid and steel slag powder are in a mass ratio of 0.01 to 0.05:

100.

4. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (2), the carbonization aid is any one of dilute hydrochloric acid, dilute sulfuric acid, and dilute nitric acid, or a combination of two or more thereof, with a concentration of 0.01-0.1 mol / L; the steel slag powder, water, and carbonization aid are mixed in a mass ratio of 100:0.1-10:1-10.

5. The method for preparing solid waste cementitious material from micro-carbonized steel slag according to claim 1, characterized in that: In step (3), CO2 gas is introduced into the carbon dioxide curing kettle, wherein the CO2 volume concentration of the introduced CO2 gas is 30-99%, the pressure is 0.1-0.5 MPa, the temperature range is 20-60°C, and the carbonization reaction time is 3-45 minutes.

6. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (3), the carbonized steel slag is ball-milled by a planetary ball mill, and then passed through a 74 μm square hole sieve to obtain a micro-carbonized steel slag powder, which is then dried at 100-105° C. for more than 24 hours.

7. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (4), the gypsum is one or a combination of two or more of phosphogypsum, fluorgypsum, and desulfurized gypsum, and the cement or clinker is silicate cement or clinker.

8. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (4), the mass of the micro-carbonized steel slag powder and slag accounts for more than 75% of the total of all raw material components.

9. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (4), the fly ash is first-grade, second-grade or third-grade fly ash, the metal tailings are any one of iron tailings, copper tailings, aluminum tailings and zinc tailings, and the specific surface area of ​​the fly ash or metal tailings powder is 300-450m 2 / g.

10. The method for preparing solid waste cementitious materials from micro-carbonized steel slag according to claim 1, characterized in that: In step (4), the alkaline solution is one or a combination of two or more of sodium hydroxide and potassium hydroxide, and the concentration of the alkaline solution is 1-5 mol / L.

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