A full-solid-waste high-activity composite admixture and a preparation method thereof

Abstract

The application relates to a full-solid-waste high-activity composite admixture and a preparation method thereof, raw materials of the full-solid-waste high-activity composite admixture comprising: mixed-milling micro-powder of steel slag tailings and refining slag, and slag micro-powder; wherein the content of the mixed-milling micro-powder is 20-30 parts by weight, and the content of the slag micro-powder is 70-80 parts by weight. Through the synergistic effect of the raw material re-mixing, the activity of the admixture is improved, the stability of the chemical performance index of the admixture is ensured, the use proportion of the admixture in cement and mortar is improved, the consumption of cement is saved, and then the cost is reduced. The metallurgical industrial solid waste such as steel slag tailings, refining slag, blast furnace slag and the like is realized to be resourcefully utilized, and the problem that long-term stacking occupies land and cannot be absorbed is solved.

Description

Technical Field

[0001] This application relates to the field of solid waste resource utilization and composite admixture technology, and in particular to a highly active composite admixture made entirely of solid waste and its preparation method. Background Technology

[0002] Steel companies are paying more and more attention to the resource utilization of industrial solid waste. Steel metallurgical slag solid waste mainly includes blast furnace slag, converter steel slag and refining slag, etc., which have large output, low utilization rate and are mostly in a long-term stockpile state.

[0003] Currently, blast furnace slag is widely used in building materials such as cement, mortar, and concrete. However, due to the implementation of high-proportion pelletizing in blast furnaces in recent years, blast furnace slag production has declined year by year, resulting in inconsistent slag quality and a shortage of high-quality slag. Converter slag is a byproduct of steelmaking. After crushing and iron beneficiation, it becomes tailings, which have potential stability issues and are difficult to use directly as aggregate in the building materials industry, making large-scale disposal challenging. Refining slag is a byproduct of steel refining. With increasing demands for steel quality, the production of refining slag has increased, and simple stockpiling can easily cause soil and water pollution. Summary of the Invention

[0004] This application provides a highly active composite admixture for solid waste and its preparation method to solve the following technical problem: how to improve the effective utilization rate of iron and steel metallurgical slag solid waste.

[0005] In a first aspect, this application provides a highly active composite admixture made entirely of solid waste, wherein the raw materials of the highly active composite admixture made entirely of solid waste include:

[0006] The finely ground powder of steel slag tailings and refining slag, and slag powder; wherein, by weight,

[0007] The content of the mixed-milled micro powder is 20 to 30 parts, and the content of the slag micro powder is 70 to 80 parts.

[0008] Optionally, the steel slag tailings are 80 to 90 parts and the refining slag is 10 to 20 parts, relative to 100 parts by weight of the mixed-milled powder.

[0009] Optionally, the steel slag tailings shall meet the following characteristics: MFe content not greater than 1% by weight, binary basicity not less than 3, and particle size less than 5mm.

[0010] Optionally, the mixed-milled micro powder satisfies the following characteristics: specific surface area 400 m². 2 / kg~500m 2 / kg, with an activity index of not less than 80% after 28 days and a moisture content of less than 1%.

[0011] Optionally, the chemical composition of the mixed-milled powder includes:

[0012] CaO, SiO2, Al2O3, MgO, SO3, and Cl; where, by mass fraction,

[0013] The content of CaO is 30%–50%, the content of SiO2 is 10%–25%, the content of Al2O3 is 5%–10%, the content of MgO is 5%–8%, the content of SO3 is 0–3%, and the content of Cl is 0–0.06%.

[0014] Optionally, the slag powder satisfies the following characteristics: specific surface area 380 m². 2 / kg~450m 2 / kg, with an activity index of not less than 95% after 28 days and a moisture content of less than 1%.

[0015] Optionally, the chemical composition of the slag powder includes:

[0016] CaO, SiO2, Al2O3, MgO, SO3, and Cl; where, by mass fraction,

[0017] The content of CaO is 30%–50%, the content of SiO2 is 20%–35%, the content of Al2O3 is 10%–20%, the content of MgO is 8%–12%, the content of SO3 is 0–3%, and the content of Cl is 0–0.06%.

[0018] Secondly, this application provides a method for preparing the highly active composite admixture of all solid waste as described in the first aspect, the method comprising:

[0019] Steel slag tailings and refining slag are premixed and then ground to obtain homogenized mixed fine powder.

[0020] The homogenized and ground micro powder is mixed with slag micro powder to obtain a mixture;

[0021] The mixture is subjected to a second homogenization process to obtain a high-activity composite admixture of all solid waste.

[0022] The technical solutions provided in this application have the following advantages compared with the prior art:

[0023] The high-activity composite admixture of all solid waste provided in this application embodiment has refined slag with good grindability. The refined slag and steel slag tailings are mixed and ground to obtain mixed-milled micro powder. The mixed-milled micro powder has a good particle size distribution, and the refined slag micro powder has a smaller particle size and specific surface area. The refined slag micro powder can shorten the setting time of slag micro powder and steel slag tailings micro powder and improve the early activity index. Slag micro powder, as the main raw material, provides high compressive strength to the high-activity composite admixture of all solid waste. The mixed-milled micro powder, as an auxiliary raw material, can provide an alkaline environment with steel slag tailings micro powder and refined slag micro powder containing calcium oxide, which promotes the dissociation of amorphous slag micro powder and improves the hydration process of slag micro powder, thereby improving the activity of the composite admixture. In summary, highly active composite admixtures made from all solid waste increase the proportion of admixtures used in concrete and mortar, save cement consumption, and realize the resource utilization of metallurgical solid wastes such as steel slag tailings, refining slag, and blast furnace slag, solving the problem of long-term stockpiling and land occupation that cannot be disposed of. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic flowchart illustrating a method for preparing a highly active composite admixture for solid waste, based on some embodiments of this application.

[0027] Figure 2 This is a detailed flowchart illustrating a method for preparing a highly active composite admixture for solid waste, based on some embodiments of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0030] In this application, the terms "including" or "comprising" mean "including but not limited to".

[0031] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0032] In a first aspect, this application provides a highly active composite admixture made entirely of solid waste, wherein the raw materials of the highly active composite admixture made entirely of solid waste include:

[0033] The finely ground powder of steel slag tailings and refining slag, and slag powder; wherein, by weight,

[0034] The content of the mixed-milled micro powder is 20 to 30 parts, and the content of the slag micro powder is 70 to 80 parts.

[0035] In this embodiment, the refining slag has good grindability. The refining slag and steel slag tailings are co-milled to obtain co-milled micropowder. This co-milled micropowder has a good particle size distribution, and the refining slag micropowder has a smaller particle size and specific surface area. This refining slag micropowder can shorten the setting time of slag micropowder and steel slag tailings micropowder and improve the early activity index. Slag micropowder, as the main raw material, provides high compressive strength to this high-activity composite admixture made from all-solid waste. The co-milled micropowder, as an auxiliary raw material, along with the steel slag tailings micropowder containing calcium oxide and the refining slag micropowder, can provide an alkaline environment, promoting the dissociation of amorphous slag micropowder and improving the hydration process of the slag micropowder, thereby increasing the activity of the composite admixture. Reasonable control of the content of slag micropowder and co-milled micropowder ensures that the high-activity composite admixture made from all-solid waste has high compressive strength. For example, the content of the mixed grinding powder can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, etc.; the content of the slag powder can be 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts, etc.

[0036] In some embodiments, the steel slag tailings are 80 to 90 parts and the refining slag is 10 to 20 parts, relative to 100 parts by weight of the mixed-milled powder.

[0037] In this embodiment, the composition of steel slag tailings differs from that of the finishing mill. Steel slag contains higher levels of dicalcium silicate and tricalcium silicate active substances; the refining slag has a higher aluminum content and contains early-setting components. Excessive refining slag will reduce the compressive strength of the mixed-milled powder. Steel slag tailings powder can ensure sufficient hydration products, and an appropriate amount of refining slag can play an alkali activation role and shorten the setting time. For example, the steel slag tailings can be 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, 86 parts, 87 parts, 88 parts, 89 parts, 90 parts, etc., and the refining slag can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc.

[0038] In some embodiments, the steel slag tailings meet the following characteristics: MFe content not greater than 1% by weight, binary basicity not less than 3, and particle size less than 5mm.

[0039] In this embodiment, the steel slag tailings are obtained by mechanically crushing and magnetically separating iron from cooled converter steel slag. The MFe content is limited to ensure the grindability of the steel slag and avoid increasing grinding costs and damaging grinding equipment; the binary alkali content is limited to allow the steel slag tailings to effectively activate slag powder, thereby improving the activity index of the composite admixture; the steel slag tailings entering the mill have a suitable particle size to avoid increasing subsequent grinding work and costs. For example, the MFe content in the aforementioned steel slag tailings can be 1% by weight, 0.9% by weight, 0.8% by weight, 0.7% by weight, etc., the binary basicity can be 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, etc., and the particle size can be 4mm, 3mm, 2mm, etc.

[0040] In some embodiments, the mixed-milled micro powder satisfies the following characteristics: specific surface area 400 m². 2 / kg~500m 2 / kg, with an activity index of not less than 80% after 28 days and a moisture content of less than 1%.

[0041] In some embodiments, the chemical composition of the mixed-milled powder includes:

[0042] CaO, SiO2, Al2O3, MgO, SO3, and Cl; where, by mass fraction,

[0043] The content of CaO is 30%–50%, the content of SiO2 is 10%–25%, the content of Al2O3 is 5%–10%, the content of MgO is 5%–8%, the content of SO3 is 0–3%, and the content of Cl is 0–0.06%.

[0044] In this embodiment, the mixed-milled micro powder possessing the above-mentioned characteristics enables it to meet the activity index requirements. For example, the specific surface area of ​​this mixed-milled micro powder can be 400 m². 2 / kg, 420m 2 / kg, 440m 2 / kg, 460m 2 / kg, 480m 2 / kg, 500m 2 The 28-day activity index can be 80%, 81%, 82%, 83%, etc., and the moisture content can be 0.9%, 0.8%, 0.7%, etc. In the chemical composition of the above-mentioned mixed-milled micro-powder, the content of CaO can be 30%, 35%, 40%, 45%, 50%, etc.; the content of SiO2 can be 10%, 15%, 20%, 25%, etc.; the content of Al2O3 can be 5%, 7%, 9%, 10%, etc.; the content of MgO can be 5%, 6%, 7%, 8%, etc.; the content of SO3 can be 1%, 2%, 3%, etc.; and the content of Cl can be 0.03%, 0.04%, 0.05%, 0.06%, etc.

[0045] In some embodiments, the slag powder has the following characteristics: specific surface area 380 m² 2 / kg~450m 2 / kg, with an activity index of not less than 95% after 28 days and a moisture content of less than 1%.

[0046] In some embodiments, the chemical composition of the slag powder includes:

[0047] CaO, SiO2, Al2O3, MgO, SO3, and Cl; where, by mass fraction,

[0048] The content of CaO is 30%–50%, the content of SiO2 is 20%–35%, the content of Al2O3 is 10%–20%, the content of MgO is 8%–12%, the content of SO3 is 0–3%, and the content of Cl is 0–0.06%.

[0049] In this embodiment, the slag powder with the above-mentioned characteristics enables it to meet the activity index requirements. For example, the specific surface area of ​​this slag powder can be 380 m². 2 / kg, 390m 2 / kg, 400m 2 / kg, 410m2 / kg, 420m 2 / kg, 430m 2 / kg, 440m 2 / kg, 450m 2 The slag powder has a 28-day activity index of 95%, 96%, 97%, etc., and a moisture content of 0.9%, 0.8%, 0.7%, etc. The chemical composition of this slag powder includes: CaO content of 30%, 35%, 40%, 45%, 50%, etc.; SiO2 content of 20%, 25%, 30%, 35%; Al2O3 content of 10%, 15%, 20%, etc.; MgO content of 8%, 10%, 12%, etc.; SO3 content of 1%, 2%, 3%, etc.; and Cl content of 0.03%, 0.04%, 0.05%, 0.06%, etc.

[0050] Secondly, this application provides a method for preparing the highly active composite admixture for all solid waste as described in the first aspect. Figure 1 This is a schematic flowchart illustrating a method for preparing a highly active composite admixture for solid waste, based on some embodiments of this application; please refer to [link / reference]. Figure 1 The method includes:

[0051] S1. Steel slag tailings and refining slag are premixed and then ground to obtain homogenized mixed fine powder.

[0052] In this embodiment, the mixed-milled micro powder is made from cooled converter steel slag after mechanical crushing and magnetic separation of iron. The remaining waste slag is further crushed into steel slag tailings with a particle size of less than 5mm. The steel slag tailings and refining slag are batched and fed into a vertical mill. After grinding, drying and powder selection, the micro powder is prepared and obtained after meeting the index requirements.

[0053] S2. The homogenized and ground micro powder is mixed with slag micro powder to obtain a mixture;

[0054] In this embodiment, blast furnace slag is ground, dried, and selected to prepare micro-powder, which meets the required specifications to obtain slag micro-powder. The mixed-ground micro-powder and slag micro-powder are then fed into a double-spiral auger mixer for stirring, mixing, and homogenization to obtain a mixture.

[0055] S3. The mixture is subjected to a second homogenization treatment to obtain a high-activity composite admixture of all solid waste.

[0056] In the embodiments of this application, the mixture undergoes a secondary homogenization process during the warehousing and discharging processes, thereby achieving a high degree of homogenization of the composite admixture. Figure 2 For a detailed flowchart illustrating a method for preparing a highly active composite admixture for solid waste according to some embodiments of this application, please refer to [link / reference]. Figure 2 .

[0057] The preparation method of the high-activity composite admixture of all solid waste is based on the above-mentioned high-activity composite admixture of all solid waste. The specific raw material composition of the high-activity composite admixture of all solid waste can be referred to the above embodiments. Since the preparation method of the high-activity composite admixture of all solid waste adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0058] The high-activity composite admixture for solid waste and its preparation method provided in this application have at least the following technical effects:

[0059] (1) The use of highly active composite admixtures of all solid waste provides a way for the resource utilization of industrial solid wastes such as blast furnace slag, steel slag tailings, and refining slag, and solves the problem of long-term stockpiling of metallurgical slag that cannot be disposed of.

[0060] (2) By adding steel slag tailings, the synergistic effect of blast furnace slag and steel slag tailings can be achieved, improving the comprehensive performance of admixtures such as fluidity and activity, solving the current problems of insufficient slag supply and poor quality. At the same time, steel slag tailings are inexpensive and have a cost advantage.

[0061] (3) By adding refining slag, on the one hand, the setting time can be shortened, solving the problem of long setting time of slag powder and steel slag powder; on the other hand, the hydration activity of slag powder and steel slag powder can be improved through alkali activation, further improving the performance of the admixture.

[0062] (4) By mixing steel slag tailings and refining slag before grinding and homogenizing them in the grinding, and mixing mill-mixed powder and slag powder after grinding and homogenizing them in the mixer and silo, the two-stage double mixing measures are adopted to achieve the full homogenization effect of the admixture and ensure the stable performance of the admixture.

[0063] (5) The increased proportion of admixtures saves on cement usage, reduces costs and carbon dioxide emissions. In addition, the use of admixtures together with cement can effectively prevent the leaching of potentially harmful substances from industrial solid waste and their impact on the environment through the solidification effect of cement.

[0064] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0065] Example 1

[0066] A highly active composite admixture made entirely of solid waste comprises the following components by weight: 20 parts of mixed-milled micro powder and 80 parts of slag micro powder.

[0067] The powder is prepared by mixing and grinding 90 parts by weight of steel slag tailings and 10 parts by weight of refining slag.

[0068] Steel slag tailings are obtained by mechanically crushing and magnetically separating iron from cooled converter steel slag. The steel slag tailings have an MFe content of 0.9%, a binary basicity of 3.6, and a particle size of less than 5 mm.

[0069] The specific surface area of ​​the mixed-milled micro powder is 450m². 2 / kg, moisture 0.9%, the main components by mass percentage are CaO 45.83%, SiO2 13.31%, Al2O3 8.42%, MgO 6.14%, SO3 0.36%, Cl 0.03%.

[0070] The specific surface area of ​​slag powder is 420m². 2 / kg, moisture 0.8%, the main components by mass percentage are CaO 42.25%, SiO2 33.61%, Al2O3 15.13%, MgO 8.02%, SO3 2.05%, Cl 0.05%.

[0071] A method for preparing a highly active composite admixture for solid waste includes:

[0072] After the cooled converter steel slag is mechanically crushed and magnetically separated for iron, the remaining waste slag is further crushed into steel slag tailings with a particle size of less than 5mm. The steel slag tailings and refining slag are metered and batched according to the weight proportions and fed into a vertical mill. After grinding, drying and powder selection, they are prepared into micro powder. After meeting the index requirements, mixed grinding micro powder is obtained.

[0073] Blast furnace slag is ground, dried, and selected to prepare micro powder, which is then obtained after meeting the required specifications.

[0074] The mixed mill powder and slag powder are metered and batched according to weight proportions, and then fed into a double spiral auger mixer for stirring, mixing and homogenization to obtain a high-activity composite admixture of all solid waste.

[0075] Example 2

[0076] Comparing Example 2 with Example 1, the difference between Example 2 and Example 1 is as follows:

[0077] The specific surface area of ​​the mixed-milled micro powder is 400m². 2 / kg.

[0078] The specific surface area of ​​slag powder is 380m². 2 / kg.

[0079] Example 3

[0080] Comparing Example 3 with Example 1, the difference between Example 3 and Example 1 is as follows:

[0081] The specific surface area of ​​the mixed-milled micro powder is 500m². 2 / kg.

[0082] The specific surface area of ​​slag powder is 450m². 2 / kg.

[0083] Example 4

[0084] Comparing Example 4 with Example 1, the difference between Example 4 and Example 1 is as follows:

[0085] Mixed milled powder 30 parts, slag powder 70 parts.

[0086] The mixed-grind micro powder consists of 90 parts steel slag tailings and 10 parts refining slag.

[0087] Example 5

[0088] Comparing Example 5 with Example 1, the difference between Example 5 and Example 1 is as follows:

[0089] 20 parts of mixed milled powder and 80 parts of slag powder.

[0090] The mixed-grind micro powder includes 80 parts of steel slag tailings and 20 parts of refining slag.

[0091] Example 6

[0092] Comparing Example 6 with Example 1, the difference between Example 6 and Example 1 is as follows:

[0093] 25 parts of mixed milled powder and 75 parts of slag powder.

[0094] The mixed-grind micro powder includes 85 parts of steel slag tailings and 15 parts of refining slag.

[0095] The specific surface area of ​​the mixed-milled micro powder is 450m². 2 / kg.

[0096] The specific surface area of ​​slag powder is 420m². 2 / kg.

[0097] Comparative Example 1

[0098] Comparing Comparative Example 1 and Example 1, the difference between Comparative Example 1 and Example 1 is as follows:

[0099] 100 parts of slag powder were used alone as an admixture.

[0100] Comparative Example 2

[0101] Comparing Comparative Example 2 with Example 1, the difference between Comparative Example 2 and Example 1 is as follows:

[0102] 80 parts of slag powder, 20 parts of steel slag tailings powder, and no refining slag powder is added to the composite admixture.

[0103] Comparative Example 3

[0104] Comparing Comparative Example 3 with Example 1, the difference between Comparative Example 4 and Example 1 is as follows:

[0105] 75 parts of steel slag tailings and 25 parts of refining slag.

[0106] In accordance with the testing requirements specified in GB / T 28293-2012 "Iron Slag Powder" standard, the performance of the admixtures in the above embodiments was tested at a cement-to-composite admixture ratio of 1:1. The test results, such as activity index and setting time, are shown in Table 1.

[0107] Table 1 Performance test results of composite admixtures

[0108]

[0109] The activity index refers to the ratio of the compressive strength of a mortar specimen prepared with 50% composite admixture and 50% reference cement to that prepared with reference cement, cured under standard conditions to the same specified age. Setting time (min) and soundness were tested according to the national standard GB / T 1346-2011, "Test Methods for Standard Consistency Water Requirement, Setting Time and Soundness of Cement".

[0110] As shown in Table 1 of the test results, the 7-day activity index of the high-activity composite admixture of solid waste provided in this application is greater than 75%, and the 28-day activity index is greater than 90%. A comparison of the results from Examples 1, 2, and 3 shows that the activity of the composite admixture is improved and the setting time is shortened with the increase of specific surface area. A comparison of the results from Examples 1, 4, and 6 shows that the 7-day and 28-day activity indices gradually increase with the increase of the proportion of mixed-milled micro-powder. A comparison of the results from Examples 1, 5, and 6 shows that an increase in the proportion of refining slag in the mixed micro-powder leads to an increase in the activity index of admixture 7 and a shortening of the initial and final setting times. The results from Comparative Example 1 show that the activity index is slightly lower without the addition of refining slag and steel slag tailings. The results from Comparative Example 2 show that the activity index is low and the setting time is longer without the addition of refining slag. Comparative Example 3 shows that adding too much refining slag will result in an excessively short setting time for the admixture.

[0111] Therefore, the high-activity composite admixture for all solid waste provided in this application provides a way to utilize the resources of metallurgical solid waste such as blast furnace slag, steel slag tailings, and refining slag. It not only reduces costs and saves cement usage and carbon emissions, but also has stable performance and can meet the performance index requirements of admixtures.

[0112] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A highly active composite admixture made entirely from solid waste, characterized in that, The raw materials for the high-activity composite admixture made from solid waste are: The finely ground powder of steel slag tailings and refining slag, and slag powder; wherein, by weight, The content of the mixed-milled micro powder is 20 parts to 30 parts, and the content of the slag micro powder is 70 parts to 80 parts; Relative to 100 parts by weight of the mixed-milled micro powder, the steel slag tailings are 80 to 90 parts, and the refining slag is 10 to 20 parts; The steel slag tailings meet the following requirements: MFe content not greater than 1% by weight, binary basicity not less than 3, and particle size less than 5mm. The mixed-milled micro powder has a specific surface area of ​​400 m². 2 / kg~500m 2 / kg, with an activity index of not less than 80% after 28 days and a moisture content of less than 1%; The slag powder has a specific surface area of ​​380m². 2 / kg~450m 2 / kg, with an activity index of not less than 95% after 28 days and a moisture content of less than 1%.

2. The highly active composite admixture for solid waste according to claim 1, characterized in that, The chemical composition of the mixed-milled micro powder includes: CaO, SiO2, Al2O3, MgO, SO3, and Cl; where, by mass fraction, The content of CaO is 30%~50%, the content of SiO2 is 10%~25%, the content of Al2O3 is 5%~10%, the content of MgO is 5%~8%, the content of SO3 is 0~3%, and the content of Cl is 0~0.06%.

3. The highly active composite admixture for solid waste according to claim 1, characterized in that, The chemical composition of the slag powder includes: CaO, SiO2, Al2O3, MgO, SO3, and Cl; where, by mass fraction, The content of CaO is 30%~50%, the content of SiO2 is 20%~35%, the content of Al2O3 is 10%~20%, the content of MgO is 8%~12%, the content of SO3 is 0~3%, and the content of Cl is 0~0.06%.

4. A method for preparing a highly active composite admixture for solid waste according to any one of claims 1 to 3, characterized in that, The method includes: Steel slag tailings and refining slag are premixed and then ground to obtain homogenized mixed fine powder. The homogenized and ground micro powder is mixed with slag micro powder to obtain a mixture; The mixture is subjected to a second homogenization process to obtain a high-activity composite admixture of all solid waste.

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