A portland cement based on steel slag optimized grading and a method for preparing the same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN UNIV OF TECH
- Filing Date
- 2026-02-09
- Publication Date
- 2026-06-02
Smart Images
Figure SMS_3 
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Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials technology, and in particular to a silicate cement based on optimized steel slag gradation and its preparation method. Background Technology
[0002] Silicate cement is a commonly used cementitious material in building materials, but the production of cement clinker results in a large amount of CO2 emissions, which harms the environment. Limestone, as the main raw material for clinker production, releases a large amount of CO2 during calcination and decomposition. Therefore, reducing the amount of limestone used can significantly reduce carbon emissions.
[0003] Steel slag is a major solid waste generated by the iron and steel industry. Its chemical composition contains significant amounts of CaO, Fe2O3, and SiO2, meeting the requirements for preparing silicate cement clinker. Therefore, using steel slag to replace part of limestone and iron-based corrective raw materials in the preparation of silicate cement clinker has become a feasible technical solution. However, the utilization rate of steel slag has remained low, mainly due to its high grinding energy consumption, limited reactivity, and large performance fluctuations. These defects directly affect its uniformity and reaction efficiency in cement raw materials, resulting in poor mechanical properties of the cement.
[0004] Therefore, a technical solution is needed that ensures the mechanical properties of cement while reducing energy consumption and utilizing solid waste. Summary of the Invention
[0005] In view of this, this application provides a silicate cement based on optimized steel slag gradation and its preparation method, which is used to solve the problem of how to ensure the mechanical properties of cement while reducing energy consumption and utilizing solid waste.
[0006] To achieve the above technical objectives, this application adopts the following technical solution:
[0007] In a first aspect, this application provides a silicate cement based on optimized gradation of steel slag, comprising the following components by mass: 100 parts of steel slag silicate cement clinker and 3-5 parts of gypsum; wherein the steel slag silicate cement clinker comprises the following components by mass: 23.6-44.1 parts of C3S, 35.3-54.6 parts of C2S, 0.5-1.7 parts of C3A, and 14.6-21.4 parts of C4AF.
[0008] Preferably, the optimized graded steel slag includes steel slag particles with decreasing gradation of size D1, size D2, and size D3.
[0009] Preferably, the particle size D1 is 0.15~0.30mm, and the steel slag particles with particle size D1 account for 15~25wt% of the optimized graded steel slag; the particle size D2 is 0.075~0.15mm, and the steel slag particles with particle size D2 account for 25~35wt% of the optimized graded steel slag; the particle size D3 is... The steel slag particles with a diameter of 0.075 mm and a particle size of D3 account for 45~55 wt% of the optimized graded steel slag.
[0010] Preferably, the optimized graded steel slag further includes a grinding aid.
[0011] Preferably, the grinding aid includes one or more of organic amines, inorganic sulfates, sugar alcohols, and polycarboxylic acid additives.
[0012] Secondly, this application provides a method for preparing silicate cement based on optimized steel slag gradation, comprising the following steps: S1. The dried raw steel slag is ground and sieved to obtain optimized graded steel slag; S2. Using the optimized graded steel slag, limestone, sandstone, and fly ash as raw materials, the steel slag silicate cement clinker is obtained through calcination treatment; S3. Mix the steel slag silicate cement clinker with gypsum to obtain the silicate cement.
[0013] Preferably, in step S1, the raw steel slag and grinding aid are ground and then placed into a sieve with a pore size gradient for sieving to obtain the optimized graded steel slag.
[0014] Preferably, the grinding aid accounts for 0.01~0.05% of the mass of the original steel slag; the screen with the aperture gradient is a set of screens with apertures of 0.075mm, 0.15mm and 0.30mm.
[0015] Preferably, in step S2, the steel slag silicate cement clinker is obtained by calcination of 65.1~70.4 parts limestone, 10.1~14.9 parts optimized graded steel slag, 10.7~12.3 parts sandstone, and 7.2~9.3 parts fly ash.
[0016] Preferably, the calcination temperature is 1300~1400℃.
[0017] The beneficial effects of this application are as follows: By replacing part of the limestone with industrial waste steel slag as raw material, this application significantly improves the utilization rate of steel slag in the building materials industry, helps alleviate its stockpiling pressure, and directly reduces the consumption of limestone in cement production and the corresponding carbon emissions from carbonate decomposition. Secondly, by pre-treating and optimizing the gradation of the steel slag, it is allowed to retain some particles of reasonable size, eliminating the need for all ultrafine grinding, thereby significantly reducing grinding energy consumption. The functional grinding aid used, through the synergistic effect of lattice activation and mechanical activation, directionally improves the grindability of steel slag, releases its activity, and passivates its unfavorable components, laying the foundation for subsequent efficient calcination. Furthermore, the optimized gradation of the steel slag achieves a gradient reaction during calcination, in which fine particles rapidly form a liquid phase to promote mass transfer, while coarse particles are activated and participate in the reaction. The C2S and C2F mineral components contained in the steel slag effectively promote the low-temperature formation and good development of the main minerals C3S and C4AF in the clinker, thereby reducing the difficulty of calcination while improving the overall quality of clinker and the mechanical properties of cement. Detailed Implementation
[0018] The embodiments of the technical solution of this application are described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.
[0019] Unless otherwise explicitly defined and specified herein, all technical and scientific terms used in this application shall have the generally accepted meanings understood by one of ordinary skill in the field of chemical and chemical materials technology (including but not limited to polymer chemistry, inorganic chemistry, organic synthesis, catalysis chemistry, materials processing, and chemical unit operations) based on their professional knowledge and conventional practice. The use of any terminology herein is intended to describe the specific embodiments of this application in the clearest and most accurate manner, so as to fully disclose the technical solution. Such use shall not in any way be construed as a limitation on the scope of the claims, nor does it imply the exclusion of equivalent technical solutions that could be reasonably known by one of skill in the art based on the concept of this application.
[0020] The terms "comprising," "including," "having," "containing," and any grammatical variations or similar expressions used in the specification and claims of this application are all open-ended and non-exhaustive descriptive terms. Their purpose is to explicitly describe the existence of the stated technical features, components, steps, or parts, while explicitly allowing and covering the possibility that other features, components, steps, parts, or any combinations thereof not explicitly listed may exist or be added to the technical solution, as long as such additions do not destroy the integrity and inventiveness of the original technical solution.
[0021] For ease of description and distinction, ordinal numbers, letters, or designations such as "first," "second," "A," "B," "step one," and "component I" may be used in the specification and claims to refer to different technical features or objects. Such designations are used solely for distinction and reference in the text and should absolutely not be construed as implying or indicating any sequential, importance, primary or secondary, spatial or temporal relationship between the objects they modify. For example, "first reactor" and "second reactor" simply indicate two different reaction apparatuses and do not imply primary or secondary or a fixed connection order.
[0022] In this paper, unless the context explicitly and specifically qualifies otherwise, the terms “multiple,” “several,” “several kinds,” “multiple steps,” “multiple groups,” “multiple copies,” etc., used to describe quantity, all refer to a quantity of two or more. For example, “multiple outlets” means at least two outlets; “multiple parallel experiments” means at least two groups of experiments.
[0023] When the terms "embodiments," "some embodiments," or "specific embodiments" are mentioned in the specification, they refer to examples that, in conjunction with the specific parameters, materials, steps, and results described in that section, constitute one or a group of examples for implementing the technical solutions of this application. These embodiments are used for full disclosure and illustrative purposes, not for exhaustive enumeration. Those skilled in the art should understand that, without departing from the overall inventive concept of this application, the various technical features disclosed in different embodiments can be combined, substituted, modified, or deleted to form other implementation methods that are not listed one by one in the specification but also fall within the protection scope of this application.
[0024] The term "and / or" describes a logical relationship between multiple related objects, indicating that any one or any combination of the listed options can exist. Specifically, "A and / or B" covers three scenarios: A exists alone; B exists alone; and A and B exist simultaneously. This logical relationship continues when more options are involved. Furthermore, the character " / " used alone often indicates an "or" relationship between the objects it connects, such as "heating / cooling device," which refers to a device with heating or cooling functions.
[0025] Unless otherwise expressly specified and limited, all terms related to chemical process operations, material preparation, processing, and analytical testing used in this application should be interpreted in the broadest sense based on the conventional understanding of those skilled in the art. Specific details are as follows: Regarding raw materials and formulation, "providing" means obtaining materials by any feasible means; "pretreatment" includes, but is not limited to, drying, grinding, sieving, activation, purification, dissolving, or premixing; "mixing" or "blending" covers any method that brings materials into contact and distribution, such as mechanical stirring, high-speed shearing, ultrasonic dispersion, ball milling, melt blending, and solution blending; "dissolving" or "dispersing" means forming a homogeneous or stable system in a suitable medium.
[0026] Regarding chemical reactions and processes, "reaction" includes, but is not limited to, various polymerization, condensation, addition, substitution, redox, catalytic conversion, metathesis, hydrolysis, and esterification processes, which can be carried out in homogeneous or multiphase systems; "contact" or "addition" includes one-time, batch, continuous, or dropwise addition; "heating" means raising the system to the desired temperature range using any heat source; "cooling" means lowering the system temperature by appropriate means; "in an atmosphere" means operating in an air, inert gas, active gas, or vacuum environment; "stirring" aims to promote mixing and mass transfer; "reaction time" refers to the time period required from the attainment of reaction conditions to the desired degree of reaction.
[0027] Regarding separation, purification, and post-processing, "separation" includes operations such as filtration, centrifugation, distillation, extraction, crystallization, precipitation, chromatography, and membrane separation; "washing" refers to cleaning the product with a suitable liquid to remove impurities; "drying" refers to removing residual solvents or moisture, and methods include atmospheric pressure, vacuum, spray drying, or freeze drying; "purification" or "refining" refers to improving product purity through a combination of the above methods; "recovery" involves the collection and treatment of solvents, raw materials, or by-products; "molding and processing" includes processes such as molding, extrusion, injection molding, casting, and coating; "heat treatment" includes operations that change the material structure through temperature control, such as annealing, quenching, and sintering; and "modification" or "surface treatment" includes methods such as chemical modification, physical blending, filling, coating, and etching.
[0028] Regarding performance testing and structural characterization, all testing and characterization methods involved in this application, unless otherwise specified, refer to conventional methods known in the art. Specific testing conditions may be selected and adjusted according to the sample properties and relevant national standards, international standards, or industry-standard methods. Test items may include mechanical properties (such as tensile, bending, and impact strength), thermal properties (such as DSC and TGA analysis), and chemical stability (such as solvent resistance and acid / alkali corrosion resistance). Structural characterization methods may include FT-IR, NMR, XRD, SEM, TEM, and BET. All test results should be understood to be within the allowable range of conventional experimental errors.
[0029] Regarding numerical values and ranges, all parameter ranges expressed in this application in the form of "from a certain value to a certain value" should be understood as explicitly disclosing the endpoints of the range, each specific numerical point between the endpoints, and all sub-ranges formed by any two numerical points within the range. For example, "30℃ to 80℃" discloses 30, 31, ..., 80℃, as well as sub-ranges such as 30-50℃, 45-70℃, etc. When a numerical value is preceded by "about," "approximately," or similar words, it indicates that the numerical value is allowed to have reasonable errors recognized in the art under the measurement or control conditions, which can generally be understood as the deviation allowed by relevant standards or a normal fluctuation range of ±5% or ±10%.
[0030] The technical solution of this application will be further described below through specific embodiments. Unless otherwise specified, the raw materials and reagents used in the embodiments are all commercially available conventional products. Operating methods not specified in the embodiments are generally performed according to conventional conditions in the art or conditions recommended by material suppliers. Any simple variations, equivalent substitutions, or reasonable combinations based on the inventive concept of this application should be considered to fall within the protection scope of this application.
[0031] This application provides a silicate cement based on optimized gradation of steel slag, comprising the following components by mass: 100 parts of steel slag silicate cement clinker and 3-5 parts of gypsum; wherein the steel slag silicate cement clinker comprises the following components by mass: 23.6-44.1 parts of C3S, 35.3-54.6 parts of C2S, 0.5-1.7 parts of C3A, and 14.6-21.4 parts of C4AF.
[0032] This application uses steel slag to replace part of the limestone as a raw material, which reduces the amount of limestone used, further reduces carbon emissions in cement clinker production, improves the utilization rate of industrial waste steel slag in the building materials industry, and helps to improve the problem of large stockpiles of steel slag; at the same time, the composition and proportion of steel slag silicate cement clinker are conducive to maintaining the 28-day compressive strength of cement.
[0033] In some embodiments, the optimized graded steel slag includes steel slag particles with decreasing gradation of size D1, size D2, and size D3.
[0034] In this embodiment, industrial waste steel slag is optimized in its gradation to allow the retention of some particles of a reasonable size, eliminating the need to grind all of it to the 75-micron level, which significantly reduces the power consumption during the grinding stage. At the same time, steel slag particles of different sizes form a gradient reaction during calcination, with medium and fine particles reacting rapidly to form a molten liquid phase that promotes the reactivity of coarse particles at high temperatures. The inherent C2S and C2F in the steel slag promote the formation and development of minerals C3S and C4AF, effectively improving the mineral structure, crystal morphology, and grindability of the clinker.
[0035] In some embodiments, the particle size D1 is 0.15~0.30mm, and the steel slag particles with particle size D1 account for 15~25wt% of the optimized graded steel slag; the particle size D2 is 0.075~0.15mm, and the steel slag particles with particle size D2 account for 25~35wt% of the optimized graded steel slag; the particle size D3 is... The steel slag particles with a diameter of 0.075 mm and a particle size of D3 account for 45~55 wt% of the optimized graded steel slag.
[0036] In this embodiment, the proportion of steel slag particles with decreasing particle size increases sequentially. The advantage of this is that by using the minimum amount of coarse particles as the skeleton and a large amount of fine particles as the reaction "initiator" and "filler", the optimal balance between reaction rate and reaction completeness is achieved. If there are too many large-diameter particles, the reaction will be insufficient, the free calcium oxide content in the clinker will increase, and the mineral development will be incomplete. If there are too many small-diameter particles, the particle agglomeration and clinker granulation will be too dense, which will have an adverse effect on the mechanical properties of cement.
[0037] In some embodiments, the optimized graded steel slag further includes a grinding aid.
[0038] In some embodiments, the grinding aid includes one or more of organic amines, inorganic sulfates, sugar alcohols, and polycarboxylic acid additives.
[0039] In some embodiments, the grinding aid is triethanolamine.
[0040] In this embodiment, the grinding aid is a functional additive that improves the activity of steel slag, enhances the grindability of steel slag, and eliminates the adverse effects of steel slag. Through the synergistic effect of lattice activation and mechanical activation, it directionally cleaves the RO phase in steel slag, making it uniformly dispersed in the steel slag composition, which helps to improve mass transfer efficiency and calcination of silicate cement clinker.
[0041] This application provides a method for preparing silicate cement based on optimized gradation of steel slag, comprising the following steps: S1. The dried raw steel slag is ground and sieved to obtain optimized graded steel slag; S2. Using the optimized graded steel slag, limestone, sandstone, and fly ash as raw materials, the steel slag silicate cement clinker is obtained through calcination treatment; S3. Mix the steel slag silicate cement with gypsum to obtain the silicate cement.
[0042] In some embodiments, in step S1, the original steel slag and grinding aid are ground and then placed into a sieve with a pore size gradient for sieving to obtain the optimized graded steel slag.
[0043] In some embodiments, the grinding aid accounts for 0.01~0.05% of the mass of the original steel slag; the screen with the aperture gradient is a set of screens with apertures of 0.075mm, 0.15mm and 0.30mm.
[0044] In this embodiment, if the amount of grinding aid is too small, the grinding effect will be poor, the steel slag particles will not be fine enough, resulting in an increase in the free calcium oxide content in the clinker and insufficient formation of target minerals such as C3S and C4AF. If the amount of grinding aid is too large, the marginal benefit of the grinding effect will be reduced, and the decomposition of excessive organic matter at high temperature will disrupt the firing atmosphere and affect the normal crystallization of the target minerals.
[0045] Specifically, step S1, preparing optimized graded steel slag, is as follows: S11. Weigh the raw steel slag dried at 105±5℃ and the grinding aid and put them into a ball mill. The amount of grinding aid is 0.01~0.05% of the mass of the raw steel slag. Ball mill for 5~10 minutes. S12. After grinding, place the mixture into a set of sieves with apertures of 0.075mm, 0.15mm, and 0.30mm, and sieve for 10-15 minutes; S13. Collect particles with particle sizes D1, D2, and D3 from the sieve, weigh them according to the design ratio, and mix them for 10-15 minutes to obtain optimized graded steel slag.
[0046] In some embodiments, in step S2, the steel slag silicate cement clinker is obtained by calcination of 65.1~70.4 parts limestone, 10.1~14.9 parts optimized graded steel slag, 10.7~12.3 parts sandstone, and 7.2~9.3 parts fly ash.
[0047] In this embodiment, to prepare steel slag silicate cement clinker containing 23.6–44.1 parts C3S, 35.3–54.6 parts C2S, 0.5–1.7 parts C3A, and 14.6–21.4 parts C4AF, the types and amounts of raw materials were limited. Optimized graded steel slag containing CaO, Fe2O3, and SiO2 was used to replace part of the limestone. This approach helps reduce carbon emissions in cement clinker production and ensures the desired amounts of the above components are obtained. Excessive use of optimized graded steel slag leads to a significant decrease in C3S content, excessive C4AF, and abnormal C3A content. Conversely, insufficient use of optimized graded steel slag results in increased free calcium oxide content, low C4AF content, and, under high KH values, insufficient liquid phase, hindering C3S formation and potentially increasing C2S.
[0048] In some embodiments, the calcination temperature is 1300~1400℃.
[0049] In this embodiment, if the calcination temperature is too high, it will lead to the decomposition of C3S and the coarsening of mineral crystals in the clinker; if the calcination temperature is too low, it will lead to insufficient liquid phase, making it difficult for C3S to form, and C2S and C4AF will not develop fully.
[0050] The following specific embodiments further illustrate this solution.
[0051] Source of raw materials The composition of limestone, steel slag, sandstone, and fly ash is shown in Table 1.
[0052] Table 1 Component Content
[0053] Example 1 A silicate cement based on optimized gradation of steel slag comprises the following components by mass: 100 parts steel slag silicate cement clinker and 3 parts gypsum; wherein the steel slag silicate cement clinker comprises the following components by mass: 44.1 parts C3S, 35.3 parts C2S, 1.7 parts C3A, and 14.6 parts C4AF.
[0054] The preparation method of silicate cement based on optimized steel slag gradation includes the following steps: S11. Weigh out the raw steel slag, spread it evenly on a shelf, and put it into an electric drying oven with a target temperature of 105℃ to dry it. Weigh out 0.05% of the mass of the raw steel slag as triethanolamine grinding aid, and put it into a ball mill together with the dried raw steel slag and grind for 10 minutes. S12. Place screens with apertures of 0.075mm, 0.15mm, and 0.30mm on the screening machine from bottom to top, with the bottom plate at the bottom. Put the ground raw steel slag into the top screen and then vibrate the screen for 15 minutes. S13. Collect steel slag particles with particle sizes D1, D2, and D3 from the sieve, and use an electronic balance to mix them according to the following proportions: 15% of particles with a D1 size of 0.15~0.30mm, 30% of particles with a D2 size of 0.075~0.15mm, and 30% of particles with a D3 size of... 0.075mm particles account for 55%. Steel slag particles of three different sizes are weighed separately and then put into a mixer and mixed for 15 minutes to obtain optimized graded steel slag. S2. Accurately weigh the following raw materials by weight percentage: 70.4 parts limestone, 10.1 parts optimized graded steel slag, 12.3 parts sandstone, and 7.2 parts fly ash; mix the raw materials evenly, place them in a box-type high-temperature furnace and calcine to 1300℃ and keep warm for 30 min, then rapidly cool to obtain steel slag silicate cement clinker. S3. Steel slag silicate cement clinker and gypsum are mixed and stirred evenly to obtain steel slag silicate cement, wherein the amount of gypsum is 3% of the mass of steel slag silicate cement clinker.
[0055] Example 2 A silicate cement based on optimized gradation of steel slag is the same as in Example 1, except that the steel slag silicate cement clinker contains the following components by mass: 23.6 parts C3S, 54.6 parts C2S, 0.5 parts C3A, and 21.3 parts C4AF.
[0056] The preparation method of silicate cement based on optimized gradation of steel slag is the same as in Example 1, except that in step S2, the weight percentage of raw materials is: limestone 64.6 parts, optimized gradation steel slag 14.9 parts, sandstone 11.5 parts, and fly ash 9 parts; wherein, the gradation of the optimized gradation steel slag is as follows: particles with a particle size D1 of 0.15~0.30mm account for 20%, particles with a particle size D2 of 0.075~0.15mm account for 35%, and particles with a particle size D3 of... 0.075mm particles account for 45%; in step S3, the gypsum content is 4% of the mass of steel slag silicate cement clinker.
[0057] Example 3 A silicate cement based on optimized gradation of steel slag is the same as in Example 1, except that the steel slag silicate cement clinker contains the following components by mass: 31.9 parts C3S, 46.0 parts C2S, 0.7 parts C3A, and 21.4 parts C4AF.
[0058] The preparation method of silicate cement based on optimized gradation of steel slag is the same as in Example 1, except that in step S2, the weight percentage of raw materials is: limestone 65.1 parts, optimized gradation steel slag 14.9 parts, sandstone 10.7 parts, and fly ash 9.3 parts; wherein, the gradation of the optimized gradation steel slag is as follows: particles with a particle size D1 of 0.15~0.30mm account for 25%, particles with a particle size D2 of 0.075~0.15mm account for 25%, and particles with a particle size D3 of... 0.075mm particles account for 50%; in step S3, the gypsum content is 5% of the mass of steel slag silicate cement clinker.
[0059] Example 4 A silicate cement based on optimized steel slag gradation is identical to Example 1 in all other aspects, except that the optimized steel slag gradation is as follows: particles with a particle size D1 of 0.15~0.30mm account for 10%, particles with a particle size D2 of 0.075~0.15mm account for 20%, and particles with a particle size D3 of... 70% of the particles are 0.075mm. The steel slag silicate cement clinker contains the following components by mass: 42.3 parts C3S, 36.0 parts C2S, 0.6 parts C3A, and 21.1 parts C4AF.
[0060] Comparative Example 1 The standard cement contains the following components by mass: 62.58 parts CaO, 4.78 parts Al2O3, 3.38 parts Fe2O3, 20.54 parts SiO2, and 3.60 parts MgO.
[0061] Comparative Example 2 A silicate cement based on optimized steel slag gradation, otherwise identical to Example 1, except that the optimized gradation steel slag particle size is [missing information]. The steel slag particles of 0.075mm account for 100%, and the steel slag silicate cement clinker contains the following components by mass: 41.7 parts C3S, 36.9 parts C2S, 0.5 parts C3A, and 20.9 parts C4AF.
[0062] Comparative Example 3 A silicate cement based on optimized steel slag gradation is the same as in Example 1, except that the optimized gradation steel slag particles with a particle size of 0.075~0.15mm account for 100%, and the steel slag silicate cement clinker contains the following components by mass: 42.0 parts C3S, 36.4 parts C2S, 0.6 parts C3A, and 21.0 parts C4AF.
[0063] Comparative Example 4 A silicate cement based on optimized gradation of steel slag is the same as that in Example 1, except that step S11 does not include the addition of grinding aids. The steel slag silicate cement clinker contains the following components by mass: 43.7 parts C3S, 36.0 parts C2S, 1.6 parts C3A, and 14.4 parts C4AF.
[0064] Testing and Evaluation The silicate cements prepared in different embodiments and comparative examples were molded into specimens according to the GB / T17671-2021 standard, and the compressive strength of the specimens after 28 days was tested. The results are shown in Table 2.
[0065] Table 2 Test Results
[0066] As can be seen from Table 2, the steel slag silicate cement prepared in the embodiments of this application all meet the 52.5 cement standard, indicating that the silicate cement clinker prepared by using optimized graded steel slag was successfully prepared, and no obvious deterioration was found during the experiment. While reducing energy consumption and utilizing solid waste, the performance of cement was guaranteed.
[0067] This invention reduces the limestone usage rate by replacing part of the limestone in the calcination of silicate cement clinker with steel slag. Simultaneously, steel slag can replace corrective raw materials such as iron ore powder, reducing the variety of industrial raw materials used in clinker calcination and lowering the calcination difficulty. Furthermore, this invention pre-treats the steel slag by adding grinding aids to improve its grindability and prematurely release its expansion characteristics, resulting in optimized graded steel slag. This achieves the goals of reducing energy consumption in steel slag grinding, increasing its reactivity, and improving the performance of silicate cement.
[0068] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A silicate cement based on optimized steel slag gradation, characterized in that, The components include the following components by weight: 100 parts steel slag silicate cement clinker and 3-5 parts gypsum; wherein the steel slag silicate cement clinker includes the following components by weight: 23.6-44.1 parts C3S, 35.3-54.6 parts C2S, 0.5-1.7 parts C3A, and 14.6-21.4 parts C4AF.
2. The silicate cement based on optimized steel slag gradation according to claim 1, characterized in that, Optimized graded steel slag includes steel slag particles with decreasing gradation, namely, D1, D2, and D3 size.
3. The silicate cement based on optimized steel slag gradation according to claim 2, characterized in that, The particle size D1 is 0.15~0.30mm, and the steel slag particles with particle size D1 account for 15~25wt% of the optimized graded steel slag; the particle size D2 is 0.075~0.15mm, and the steel slag particles with particle size D2 account for 25~35wt% of the optimized graded steel slag; the particle size D3 is... The steel slag particles with a diameter of 0.075 mm and a particle size of D3 account for 45~55 wt% of the optimized graded steel slag.
4. The silicate cement based on optimized steel slag gradation according to claim 2, characterized in that, The optimized graded steel slag also includes grinding aids.
5. The silicate cement based on optimized steel slag gradation according to claim 4, characterized in that, The grinding aid includes one or more of the following: organic amines, inorganic sulfates, sugar alcohols, and polycarboxylic acid additives.
6. A method for preparing silicate cement based on optimized steel slag gradation as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. The dried raw steel slag is ground and sieved to obtain optimized graded steel slag; S2. Using the optimized graded steel slag, limestone, sandstone, and fly ash as raw materials, the steel slag silicate cement clinker is obtained through calcination treatment; S3. Mix the steel slag silicate cement clinker with gypsum to obtain the silicate cement.
7. The method for preparing silicate cement based on optimized steel slag gradation according to claim 6, characterized in that, In step S1, the raw steel slag and grinding aid are ground and then placed into a sieve with a pore size gradient for sieving to obtain the optimized graded steel slag.
8. The method for preparing silicate cement based on optimized steel slag gradation according to claim 7, characterized in that, The grinding aid accounts for 0.01~0.05% of the mass of the original steel slag; the screen with the aperture gradient is a set of screens with apertures of 0.075mm, 0.15mm and 0.30mm.
9. The method for preparing silicate cement based on optimized steel slag gradation according to claim 6, characterized in that, In step S2, the steel slag silicate cement clinker is obtained by calcination of 65.1~70.4 parts limestone, 10.1~14.9 parts optimized graded steel slag, 10.7~12.3 parts sandstone, and 7.2~9.3 parts fly ash.
10. The method for preparing silicate cement based on optimized steel slag gradation according to claim 9, characterized in that, The calcination temperature is 1300~1400℃.