Novel steel slag-based cementing material and preparation method thereof

Abstract

The invention discloses a steel slag-based novel cementing material and a preparation method thereof, the steel slag is firstly crushed and then enters an iron removal process, then enters a first-stage winnowing process, and large particles are winnowed and then enter a crushing process; feeding the small particles into a ball-milling process, feeding the small particles into the ball-milling process together with the deironed blast furnace slag, calcium-containing fly ash, refining slag, a grinding aid and an exciting agent, and feeding the small particles into a secondary winnowing process after ball-milling; and winnowing small particles to obtain a finished product, and carrying out ball milling on large particles in the ball milling process again. When the raw materials are prepared, the content ratio range of CaO to SiO2 in the raw materials is controlled to be 1.2-2.5, and the content of CaO is not lower than 50%. According to the invention, the solid waste of the steel mill is used as the raw material, the cementing material with better cementing activity is prepared through appropriate raw material components, calcium-silicon ratio control and appropriate grinding process, so that the solid waste resource utilization value of the steel mill is improved, and the energy consumption in the preparation process of the cementing material is favorably reduced through control.

Description

Technical Field

[0001] The present invention relates to the technical field of slag treatment, and specifically to a new type of slag-based cementitious material and its preparation method. Background Art

[0002] Slag is the main solid waste generated during the steel smelting process. Its chemical composition is similar to that of cement clinker and has potential cementitious activity. Steel slag, calcium-containing dust removal ash from steel mills, and refining slag are also solid wastes generated during the steel production process. They have a high calcium content but a low utilization rate and are usually stacked as waste, causing waste of resources and environmental pollution. In the prior art, the preparation of slag-based cementitious materials mostly uses a single slag raw material or simply mixes other solid wastes, failing to fully utilize the solid waste resources of steel mills. Moreover, the ball milling process has high energy consumption and inaccurate control of the calcium-silicon ratio, resulting in insufficient activity of the cementitious material.

[0003] The invention patent "A preparation method of an active composite powder based on steel slag and slag" with the application number 202310407537.9 discloses a preparation method of an active composite powder based on steel slag and slag. The active composite powder includes the following components by mass: 20-50 parts of steel slag powder, 40-70 parts of slag powder, 5-15 parts of steel tailing slag powder mud, 0-10 parts of mine tailing powder mud, and 0-0.2 parts of an activity activator; wherein, the activity activator is composed of 2-15 parts of tris(isopropanol)amine maleate sulfonate, 0-15 parts of N-dodecylethanolamine, 5-15 parts of N,N-dimethylisopropanolamine, 0-1 part of polyoxypropylene glycerol ether, 10-20 parts of sodium thiosulfate, and 40-70 parts of water. This method improves the resource utilization value of solid waste, but does not involve the specific preparation method of the composite powder. If prepared by conventional methods, the energy consumption is high.

[0004] The patent "A method for mixing and treating steel slag and slag" with the application number 202010139165.2 invented a method for mixing and treating steel slag and slag, including: S1, mixing steel slag and slag to form a mixed material. The mixed material includes 0%-30% of steel slag and 70%-100% of slag by mass percentage, and the sum of the mass percentages of steel slag and slag is 100%; S2, grinding the mixed material; S3, judging whether the mixed material after grinding is fine powder. If so, it is collected by a dust collector and transported to the steel slag storage, and if not, it is ground again. This method has a simple process, but using the same grinding process to grind steel slag and slag simultaneously has high energy consumption.

[0005] The patent "A Preparation Method and Device for High-Efficiency Composite Cementitious Materials" with the application number 202310284661.0 invented a preparation method and device for high-efficiency composite cementitious materials. The method includes the following steps: Step 1: Pretreat steel slag, slag, and fly ash to obtain steel slag powder, slag powder, and pyrolyzed fly ash; Step 2: Stir and heat the steel slag powder, slag powder, pyrolyzed fly ash, and desulfurized gypsum to prepare the cementitious material. The device includes a steel slag powder silo, a slag powder silo, a fly ash powder silo, a desulfurized gypsum silo, a mixing component, and a hot air stirring silo. The bottoms of the steel slag powder silo, slag powder silo, fly ash powder silo, and desulfurized gypsum silo are all connected to the mixing component, and the bottom of the mixing component is connected to the hot air stirring silo. The present invention can achieve the purpose of synergistically and efficiently recycling fly ash, slag, steel slag, and desulfurized gypsum. This process makes full use of solid waste resources, but requires a heating process and has high energy consumption.

[0006] After retrieval, there are generally the following problems in the preparation of cementitious materials from steel plant solid waste: First, it mainly uses steel slag and slag, and the types of solid waste are limited; Second, the process energy consumption for preparing cementitious materials from solid waste is relatively high; Third, taking the proportion of raw materials as a limiting condition and not restricting the calcium-silicon ratio may affect the activity of the cementitious material. Summary of the Invention

[0007] The purpose of the present invention is to provide a new type of steel slag-based cementitious material and its preparation method. Using the solid waste of steel plants as raw materials, through appropriate control of the raw material composition and calcium-silicon ratio, and then through an appropriate grinding process, a cementitious material with good cementitious activity is prepared, which not only improves the resource utilization value of the solid waste of steel plants but also helps to reduce the energy consumption in the preparation process of the cementitious material to solve the problems raised in the above background technology.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A preparation method of a new type of steel slag-based cementitious material includes the following steps:

[0010] Step 1: First, crush the steel slag. After crushing, enter the iron removal process. After iron removal, enter the first-stage air separation process, and the large particles S1 separated by air separation enter the crushing process again;

[0011] Step 2: Send the small particles S2 into the ball milling process, and enter the ball milling process together with the blast furnace slag, calcium-containing dust removal ash, refining slag, grinding aid, and activator after iron removal. After ball milling, enter the second-stage air separation process;

[0012] Step 3: The small particles S3 separated by air separation are the finished product and enter the finished product silo, and the large particles S4 enter the ball milling process again for ball milling.

[0013] Furthermore, after the iron removal process, the content of metallic iron in blast furnace slag is less than 1%. The chemical composition of blast furnace slag is as follows: the content of CaO is 30 - 45%, the content of SiO2 is 30 - 45%, the content of MgO is 5 - 15%, the content of Al2O3 is 10 - 20%, the content of TFe is 0.1 - 2%, the content of S is 0.1 - 2%, the proportion of particles less than 5mm is greater than 95%, and the moisture content is less than 1%;

[0014] The steel slag is the tail slag after magnetic separation process, including converter steel slag and electric furnace steel slag. The chemical composition of steel slag is as follows: the content of TFe is 15 - 25%, the content of CaO is 40 - 50%, the content of SiO2 is 10 - 20%, the content of MgO is 3 - 9%, the content of Al2O3 is 0.5 - 1.5%, the content of P is 0.5 - 1.5%, all particle sizes are less than 60mm, the proportion of particles less than 25mm is greater than 50%, and the moisture content is less than 1%;

[0015] The chemical composition of calcium - containing dust - removing ash is as follows: the content of CaO is 20 - 60%, the content of SiO2 is 0.1 - 15%, the content of MgO is 0.1 - 15%, the content of Al2O3 is 0.1 - 10%, the content of TFe is 0.1 - 20%, the content of C is 0.1 - 12%, the proportion of particles less than 0.2mm is greater than 95%, and the moisture content is less than 1%;

[0016] The chemical composition of refining slag is as follows: the content of CaO is 40 - 60%, the content of SiO2 is 5 - 15%, the content of MgO is 5 - 10%, the content of Al2O3 is 15 - 30%, the content of TFe is 0.1 - 5%, the proportion of particles less than 0.3mm is greater than 95%, and the moisture content is less than 1%.

[0017] Furthermore, the crushing process adopts roller press crushing. The roll diameter of the roller press is 1000 - 1200mm, the roll speed is 1.0 - 2.0m / s, and the proportion of steel slag less than 5mm after crushing is not less than 70%.

[0018] Furthermore, the iron removal process adopts tubular magnetic separation process, the pipe diameter is 100 - 1000mm, and the magnetic field intensity ≥1.2T.

[0019] Furthermore, the ball - milling process adopts horizontal ball mill, and the ball - milling time is 30 - 60min.

[0020] Furthermore, the content of grinding aid participating in ball - milling is 0.01% - 0.1%, and the content of activator is 1% - 3%.

[0021] Furthermore, the wind speed of the first - stage air - separation process is 8 - 15m / s, and the wind speed of the second - stage air - separation process is 3 - 7m / s.

[0022] Further, the particles selected by the primary air separation process are S1≥5mm and re-enter the roll pressing and crushing, while the particles are S2≤5mm; the particles selected by the secondary air separation process are S4≥75μm and re-enter the ball milling process, and the particles S3≤75μm enter the finished product bin. The specific surface area of the finished product is 300-400m 2 / kg, passing through a 45μm sieve, and the sieve residue is ≥5%.

[0023] The present invention provides another technical solution: a new type of steel slag-based cementitious material, with the proportion of blast furnace slag being 50%-80%, the proportion of steel slag being 10%-30%, the proportion of calcium-containing dust removal ash being 5-10%, and the proportion of refining slag being 5-10%.

[0024] Further, during raw material batching, control the ratio range of the content of CaO and SiO2 in the raw materials to be 1.2-2.5, and the CaO content is not less than 50%. The calcium-silicon ratio formula is M(CaO) / M(SiO2)= [M1(CaO)+ M2(CaO)+ M3(CaO)+ M4(CaO)] / [M1(SiO2)+ M2(SiO2)+ M3(SiO2)+ M4(SiO2)], where M1, M2, M3, and M4 represent blast furnace slag, steel slag, calcium-containing dust removal ash, and refining slag respectively.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] The new type of steel slag-based cementitious material and its preparation method of the present invention realize the resource utilization of solid waste, energy conservation and consumption reduction, and product performance improvement by optimizing the collaborative treatment process of solid wastes such as blast furnace slag and steel slag, combined with multi-stage crushing, magnetic separation, air separation and activator regulation. Description of the Drawings

[0027] Figure 1 It is a flow chart of the preparation process of the present invention. Specific Embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] Please refer to Figure 1 , a preparation method of a new type of steel slag-based cementitious material is provided in the embodiments of the present invention, including the following steps:

[0030] Step 1: First, crush the steel slag. After crushing, it enters the iron removal process. After iron removal, it enters the primary air separation process. The large particles S1 separated by air separation re-enter the crushing process. Among them, the steel slag is the tail slag after the magnetic separation process, including converter steel slag and electric furnace steel slag. The chemical composition of the steel slag is as follows: TFe content is 15 - 25%, CaO content is 40 - 50%, SiO2 content is 10 - 20%, MgO content is 3 - 9%, Al2O3 content is 0.5 - 1.5%, P content is 0.5 - 1.5%. The particle size is less than 60mm, the proportion of particles less than 25mm is more than 50%, and the moisture content is less than 1%.

[0031] Step 2: Feed the small particles S2 into the ball milling process. Together with the iron-removed blast furnace slag, calcium-containing dust removal ash, refining slag, grinding aid, and activator, they enter the ball milling process. After ball milling, it enters the secondary air separation process. Among them, the blast furnace slag has undergone the iron removal process, and the metal iron content is less than 1%. The chemical composition of the blast furnace slag is as follows: CaO content is 30 - 45%, SiO2 content is 30 - 45%, MgO content is 5 - 15%, Al2O3 content is 10 - 20%, TFe content is 0.1 - 2%, S content is 0.1 - 2%. The proportion of particles less than 5mm is more than 95%, and the moisture content is less than 1%. The chemical composition of the calcium-containing dust removal ash is as follows: CaO content is 20 - 60%, SiO2 content is 0.1 - 15%, MgO content is 0.1 - 15%, Al2O3 content is 0.1 - 10%, TFe content is 0.1 - 20%, C content is 0.1 - 12%. The proportion of particles less than 0.2mm is more than 95%, and the moisture content is less than 1%. The chemical composition of the refining slag is as follows: CaO content is 40 - 60%, SiO2 content is 5 - 15%, MgO content is 5 - 10%, Al2O3 content is 15 - 30%, TFe content is 0.1 - 5%. The proportion of particles less than 0.3mm is more than 95%, and the moisture content is less than 1%. The content of the grinding aid participating in ball milling is 0.01% - 0.1%, and the content of the activator is 1% - 3%.

[0032] Step 3: The small particles S3 separated by air separation are the finished product and enter the finished product bin. The large particles S4 re-enter the ball milling process for ball milling. Among the cementitious materials of the finished product, the proportion of blast furnace slag is 50% - 80%, the proportion of steel slag is 10% - 30%, the proportion of calcium-containing dust removal ash is 5 - 10%, and the proportion of refining slag is 5 - 10%.

[0033] In the above steps, the crushing process adopts roll crushing. The roll diameter of the roll press is 1000 - 1200 mm, the roll speed is 1.0 - 2.0 m / s, and the content of steel slag below 5 mm after crushing is not less than 70%. The iron removal process adopts a tubular magnetic separation process with a pipe diameter of 100 - 1000 mm and a magnetic field strength ≥ 1.2 T. The ball milling process adopts a horizontal ball mill with a ball milling time of 30 - 60 min. The wind speed of the primary air separation process is 8 - 15 m / s, and the wind speed of the secondary air separation process is 3 - 7 m / s. The particles S1 ≥ 5 mm selected by the primary air separation process re-enter the roll crushing, and the particles S2 ≤ 5 mm; the particles S4 ≥ 75 μm selected by the secondary air separation process re-enter the ball milling process, and the particles S3 ≤ 75 μm enter the finished product bin.

[0034] The specific surface area of the cementitious material finished product obtained by the above preparation method is 300 - 400 m 2 / kg. Passing through a 45 μm sieve, the sieve residue is ≥ 5%. Among them, when formulating the raw materials, the ratio range of the content of CaO and SiO2 in the raw materials is controlled to be 1.2 - 2.5, the CaO content is not less than 50%, and the calcium-silicon ratio formula = M(CaO) / M(SiO2) = [M1(CaO) + M2(CaO) + M3(CaO) + M4(CaO)] / [M1(SiO2) + M2(SiO2) + M3(SiO2) + M4(SiO2)], where M1, M2, M3, and M4 represent blast furnace slag, steel slag, calcium-containing dust removal ash, and refining slag respectively.

[0035] To further better explain the present invention, the following specific embodiments are also provided:

[0036] Example 1:

[0037] Select blast furnace slag (CaO 38%, SiO2 35%) with a raw material ratio of 65%, steel slag (CaO 45%, SiO2 15%) with a raw material ratio of 20%, calcium-containing dust removal ash (CaO 50%, SiO2 5%) with a raw material ratio of 8%, and refining slag (CaO 55%, SiO2 10%) with a raw material ratio of 7%. The total calcium-silicon ratio of the raw materials is 1.65. The addition amount of the grinding aid (triethanolamine) is 0.05%, and the addition amount of the activator (sodium sulfate) is 2%.

[0038] The roll diameter of the roll press is selected as 1100 mm, the roll speed is 1.5 m / s, and the proportion of the steel slag with a particle size of ≤5 mm after crushing is 75%. The pipe diameter of the tubular magnetic separator is 500 mm, the magnetic field strength is 1.5 T, and the residual amount of metallic iron is ≤0.8%. Primary air separation: the air speed is 10 m / s, separating S1 (≥5 mm, returned for crushing) and S2 (≤5 mm, entering the ball mill). Horizontal ball mill, the ball milling time is 45 minutes, and the proportion of grinding media is: 30% of Φ60 mm steel balls, 50% of Φ30 mm steel balls, and 20% of Φ10 mm steel balls. Secondary air separation: the air speed is 5 m / s, separating S3 (≤75 μm, finished product) and S4 (>75 μm, returned for ball milling).

[0039] The specific surface area of the obtained cementitious material finished product is 380 m 2 / kg, and the sieve residue on a 45-μm sieve is 6.5%. The 28-day compressive strength is 48 MPa, and the activity index is 98%.

[0040] Example 2:

[0041] Selected blast furnace slag (CaO 42%, SiO2 40%), raw material proportion 70%, steel slag (CaO 48%, SiO2 12%), raw material proportion 15%, calcium-containing dust ash (CaO 40%, SiO2 10%), raw material proportion 10%, refining slag (CaO 50%, SiO2 12%), raw material proportion 5%, and the total calcium-silicon ratio of the raw materials is 1.6. The addition amount of the grinding aid (lignosulfonate) is 0.08%, and the addition amount of the activator (sodium silicate) is 3%.

[0042] The proportion of the steel slag with a particle size of ≤5 mm after crushing is 80%, and the iron content after magnetic separation is ≤0.6%. The primary air separation air speed is 12 m / s, and the return rate of S1 (≥5 mm) is 18%. The ball milling time is 50 minutes, and the filling rate of the grinding media is 35%. The secondary air separation air speed is 6 m / s, and the proportion of the finished product S3 with a particle size of ≤75 μm is 92%.

[0043] The specific surface area of the obtained cementitious material finished product is 400 m² / kg, and the sieve residue on a 45-μm sieve is 5.2%. The 28-day compressive strength is 52 MPa, and the activity index is 105%.

[0044] Comparative Example 1:

[0045] Selected blast furnace slag (CaO 38%, SiO2 35%), raw material proportion 65%, steel slag (CaO 45%, SiO2 15%), raw material proportion 20%, calcium-containing dust ash (CaO 50%, SiO2 5%), raw material proportion 8%, refining slag (CaO 55%, SiO2 10%), raw material proportion 7%, and the total calcium-silicon ratio of the raw materials is 1.65. The addition amount of the grinding aid (triethanolamine) is 0.05%, and the addition amount of the activator (sodium sulfate) is 2%.

[0046] Adopt the process of non-roll pressing and primary air separation. The tube-type magnetic separator has a tube diameter of 500 mm, a magnetic field intensity of 1.5 T, and the residual amount of metallic iron ≤ 0.8%. Horizontal ball mill, ball milling time is 60 minutes, grinding medium ratio: 30% of Φ60mm steel balls, 50% of Φ30mm steel balls, 20% of Φ10mm steel balls. Secondary air separation: air velocity is 5 m / s, separating S3 (≤75μm, finished product) and S4 (>75μm, returned to ball milling).

[0047] The specific surface area of the obtained cementitious material finished product is 360 m 2 / kg, the residue on 45μm sieve is 12%. The 28-day compressive strength is 38 MPa, and the activity index is 78%. The non-roll pressing process results in a wide particle size distribution of the finished product, a decrease in activity, and a 20% increase in power consumption.

[0048] Comparative Example 2:

[0049] Select blast furnace slag (CaO 30%, SiO2 45%), raw material proportion 50%, steel slag (CaO 40%, SiO2 20%), raw material proportion 35%, calcium-containing dust removal ash (CaO 50%, SiO2 5%), raw material proportion 8%, refining slag (CaO 55%, SiO2 10%), raw material proportion 7%, total calcium-silicon ratio of raw materials is 1.22. The addition amount of grinding aid (triethanolamine) is 0.05%, and the addition amount of activator (sodium sulfate) is 2%.

[0050] Adopt a roll press with a roll diameter of 1100 mm, a roll speed of 1.5 m / s, and the proportion of steel slag particles ≤ 5 mm after crushing is 75%. The tube-type magnetic separator has a tube diameter of 500 mm, a magnetic field intensity of 1.5 T, and the residual amount of metallic iron ≤ 0.8%. Primary air separation: air velocity is 10 m / s, separating S1 (≥5mm, returned to crushing) and S2 (≤5mm, entering ball milling). Horizontal ball mill, ball milling time is 45 minutes, grinding medium ratio: 30% of Φ60mm steel balls, 50% of Φ30mm steel balls, 20% of Φ10mm steel balls. Secondary air separation: air velocity is 5 m / s, separating S3 (≤75μm, finished product) and S4 (>75μm, returned to ball milling).

[0051] The specific surface area of the obtained cementitious material finished product is 320 m 2 / kg, the residue on 45μm sieve is 18%. The 28-day compressive strength is 28 MPa, and the activity index is 65%, with relatively low cementitious activity.

[0052] As can be seen from the above Examples 1-2 and Comparative Examples 1-2, a new type of steel slag-based cementitious material and its preparation method provided by the present invention utilize the solid waste of steel mills as raw materials, through appropriate control of raw material composition and calcium-silicon ratio, and then through an appropriate grinding process to prepare a cementitious material with good cementitious activity, which not only improves the resource utilization value of the solid waste of steel mills, but also helps to reduce the energy consumption in the preparation process of the cementitious material.

[0053] In summary, the present invention uses blast furnace slag as the main raw material, and steel slag, calcium-containing dust removal ash from steel mills, refining slag, etc. as auxiliary materials, and adds a certain amount of grinding aids and activators, which can not only ensure the activity of the cementitious material but also recycle the solid waste from steel mills; secondly, a roller pressing-iron removal-air separation process is added before the ball milling process to reduce the particle size of the steel slag entering the ball milling process and reduce the energy consumption of the ball milling process; in addition, the calcium-silicon ratio is calculated through the composition and ratio of the raw materials, and an appropriate calcium-silicon ratio is controlled to ensure the activity of the cementitious material.

[0054] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the inventive concept of the technical solution of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A preparation method of a novel steel slag-based cementitious material, characterized in that, It includes the following steps: Step 1: First, crush the steel slag. After crushing, it enters the iron removal process. After iron removal, it enters the primary air separation process. The large particles S1 separated by air separation re-enter the crushing process; Step 2: Feed the small particles S2 into the ball milling process. Together with the blast furnace slag, calcium-containing dust removal ash, refining slag, grinding aid and activator after iron removal, they enter the ball milling process. After ball milling, it enters the secondary air separation process; Step 3: The small particles S3 separated by air separation are the finished products and enter the finished product bin. The large particles S4 re-enter the ball milling process for ball milling.

2. The preparation method of a novel steel slag-based cementitious material according to claim 1, characterized in that: After passing through the iron removal process, the blast furnace slag has a metal iron content of less than 1%. The chemical composition of the blast furnace slag is: CaO content 30 - 45%, SiO2 content 30 - 45%, MgO content 5 - 15%, Al2O3 content 10 - 20%, TFe content 0.1 - 2%, S content 0.1 - 2%. The proportion of particles with a size less than 5mm is greater than 95%, and the moisture content is lower than 1%; The steel slag is the tail slag after the magnetic separation process, and the types include converter steel slag and electric furnace steel slag. The chemical composition of the steel slag is: TFe content 15 - 25%, CaO content 40 - 50%, SiO2 content 10 - 20%, MgO content 3 - 9%, Al2O3 content 0.5 - 1.5%, P content 0.5 - 1.5%. The particle size is all less than 60mm, the proportion of particles less than 25mm is greater than 50%, and the moisture content is lower than 1%; The chemical composition of the calcium-containing dust removal ash is: CaO content 20 - 60%, SiO2 content 0.1 - 15%, MgO content 0.1 - 15%, Al2O3 content 0.1 - 10%, TFe content 0.1 - 20%, C content 0.1 - 12%. The proportion of particles with a size less than 0.2mm is greater than 95%, and the moisture content is lower than 1%; The chemical composition of the refining slag is: CaO content 40 - 60%, SiO2 content 5 - 15%, MgO content 5 - 10%, Al2O3 content 15 - 30%, TFe content 0.1 - 5%. The proportion of particles with a size less than 0.3mm is greater than 95%, and the moisture content is lower than 1%.

3. The preparation method of a novel steel slag-based cementitious material according to claim 1, characterized in that: The crushing process uses roll pressing. The roll diameter of the roll press is 1000 - 1200mm, the roll speed is 1.0 - 2.0m / s, and the proportion of the crushed steel slag with a size less than 5mm is not less than 70%.

4. The preparation method of a novel steel slag-based cementitious material according to claim 1, characterized in that: The iron removal process uses a tubular magnetic separation process, the pipe diameter is 100 - 1000mm, and the magnetic field strength ≥1.2T.

5. The preparation method of a novel steel slag-based cementitious material according to claim 1, characterized in that: The ball milling process uses a horizontal ball mill, and the ball milling time is 30 - 60min.

6. The preparation method of a novel steel slag-based cementitious material according to claim 1, characterized in that: The content of the grinding aid participating in ball milling is 0.01% - 0.1%, and the content of the activator is 1% - 3%.

7. The preparation method of a novel steel slag-based cementitious material according to claim 1, characterized in that: The wind speed of the primary air separation process is 8 - 15m / s, and the wind speed of the secondary air separation process is 3 - 7m / s.

8. The preparation method of a novel steel slag-based cementitious material according to claim 1, characterized in that: The particles selected by the primary air separation process have S1≥5mm and re-enter the roll pressing and crushing process, while the particles with S2≤5mm; the particles selected by the secondary air separation process have S4≥75μm and re-enter the ball milling process, and the particles with S3≤75μm enter the finished product bin. The specific surface area of the finished product is 300 - 400m 2 / kg. Pass through a 45μm sieve, and the sieve residue is ≥5%.

9. A new steel slag-based cementitious material is prepared by using the new steel slag-based cementitious material and its preparation method as described in claim 1, and is characterized in that: In the prepared cementitious material of the finished product, the proportion of blast furnace slag is 50% - 80%, the proportion of steel slag is 10% - 30%, the proportion of calcium-containing dust removal ash is 5 - 10%, and the proportion of refining slag is 5 - 10%.

10. A novel steel slag-based cementitious material according to claim 9, characterized in that: During raw material batching, the ratio range of the content of CaO to SiO2 in the raw materials is 1.2 - 2.5, the content of CaO is not less than 50%, and the calcium-silicon ratio formula is M(CaO) / M(SiO2)=[M1(CaO)+ M2(CaO)+ M3(CaO)+ M4(CaO)] / [M1(SiO2)+ M2(SiO2)+ M3(SiO2)+ M4(SiO2)], where M1, M2, M3, and M4 represent blast furnace slag, steel slag, calcium-containing dedusted ash, and refining slag respectively.

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