Preparation method and application of super-high-activity solid waste-based carbon sequestration auxiliary cementitious material

Abstract

The application provides a preparation method and application of a super-high-activity solid waste-based carbon sequestration auxiliary cementing material, and belongs to the technical field of building materials. The method comprises the following steps: (1) pre-grinding medium-low-activity high-alumina-pozzolanic solid waste to a corresponding particle size range to obtain medium-low-activity high-alumina-pozzolanic solid waste pre-grinding micro powder, and adding corresponding composite chemical additives in the pre-grinding process; and (2) proportioning the carbon sequestration solid waste, the medium-low-activity high-alumina-pozzolanic solid waste pre-grinding micro powder and a calcium-increasing component in a specific mass ratio and superfine grinding to a corresponding particle size range to obtain the super-high-activity solid waste-based carbon sequestration auxiliary cementing material. The super-high-activity solid waste-based carbon sequestration auxiliary cementing material prepared by the method has a 30% content activity index of up to S130-S145 grade and a 50% content activity index of up to S120-S130 grade.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building materials, and particularly relates to a process method and application of super-high-activity solid waste-based carbon sequestration auxiliary cementitious material prepared by synergistically compounding carbon sequestration solid waste and medium-low-activity high-alumina pozzolanic solid waste according to an optimal CO2 / Al2O3 ratio. BACKGROUND

[0002] Cement is an important basic material supporting national economic construction, and is usually prepared by mixing silicate clinker, auxiliary cementitious material and a proper amount of gypsum. The hydration activity of the auxiliary cementitious material determines the minimum clinker coefficient (the proportion of cement clinker in the silicate cement product) and the mechanical properties of the cement product.

[0003] At present, granulated blast furnace slag is a necessary component of most high-activity (28d activity index greater than 95%) auxiliary cementitious materials, while other bulk industrial solid wastes (such as fly ash, bottom slag, steel slag, red mud, coal gangue, etc.) cannot completely replace granulated blast furnace slag for the preparation of high-activity mineral admixtures due to their poor hydration activity or slow activity development. With the continuous growth of the production capacity of cement and concrete products in China, high-activity auxiliary cementitious materials represented by granulated blast furnace slag are becoming increasingly scarce. Therefore, how to realize the preparation of high-activity or even super-high-activity (28d activity index greater than 105%) auxiliary cementitious materials using only fly ash, bottom slag, steel slag, red mud and other medium-low-activity bulk industrial solid waste without granulated blast furnace slag is a technical means that is urgently needed in the cement and concrete industry, and has significant economic and environmental benefits. SUMMARY

[0004] The application provides a preparation method of super-high-activity solid waste-based carbon sequestration auxiliary cementitious material and application thereof.

[0005] The object of the application can be achieved by the following technical solutions.

[0006] A preparation method of super-high-activity solid waste-based carbon sequestration auxiliary cementitious material, the steps of the method are as follows:

[0007] (1) Pre-milling medium-low-activity high-alumina pozzolanic solid waste to obtain medium-low-activity high-alumina pozzolanic solid waste pre-milling micro-powder, and adding corresponding composite chemical additives during the pre-milling process;

[0008] (2) mixing carbon sequestration solid waste, medium-low-activity high-alumina pozzolanic solid waste pre-milling micro-powder and calcium-increasing components, and ultrafine grinding to a predetermined particle size range to obtain super-high-activity solid waste-based carbon sequestration auxiliary cementitious material;

[0009] The predetermined particle size range is 30 mu m sieve residue < 1%, and the specific surface area is > 700 m 2 .

[0010] In the technical scheme of the present application: the obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace 30-50% of Portland cement clinker by mass ratio in the preparation of Portland cement or concrete.

[0011] In the technical scheme of the present application: in step (1), the medium-low activity high-alumina volcanic ash solid waste is one or more of fly ash, coal-fired furnace bottom slag, calcined aluminous coal gangue, and calcined clay rock coal gangue; the Al2O3 content of the medium-low activity high-alumina volcanic ash solid waste is ≥ 25 wt.%, and the medium-low activity high-alumina volcanic ash solid waste passes the volcanic ash test.

[0012] In the technical scheme of the present application: the composite chemical additive added in the pre-grinding process in step (1) is composed of 40-85 parts by mass of alcohol amine grinding aid, 10-45 parts of polycarboxylate, 0.1-3.5 parts by mass of aluminate or titanate, and 4-15 parts by mass of sodium aluminate and / or sodium ferrite; the dosage of the composite chemical additive is 2-8 ‰ of the mass of the medium-low activity high-alumina volcanic ash solid waste.

[0013] In the technical scheme of the present application: in step (1), the specific surface area of the obtained medium-low activity high-alumina volcanic ash solid waste pre-ground powder is > 500 m 2 / kg, and the 45 mu m sieve residue is < 3%.

[0014] In the technical scheme of the present application: in step (2), the carbon sequestration solid waste is one or more of carbonized steel slag, carbonized sintered red mud, carbonized magnesium slag, and carbonized waste concrete powder; the above-mentioned carbon sequestration solid waste must be obtained by dry or wet CO2 capture process carbonization of steel slag, sintered red mud, magnesium slag, and waste concrete powder, and the CO2 determination value of the carbon sequestration solid waste by asbestosis absorption weight method is ≥ 10 wt.%, and the carbon component in the carbon sequestration solid waste exists in the form of calcite-type or aragonite-type calcium carbonate.

[0015] In the technical scheme of the present application: in step (2), the calcium-increasing component is one or more of calcium carbide slag and lime.

[0016] In the technical scheme of the present application: in step (2), the mass ratio of the carbon sequestration solid waste to the medium-low activity high-alumina volcanic ash solid waste in the ultrafine grinding and proportioning, and the mass ratio of CO2 in the carbon sequestration solid waste to Al2O3 in the medium-low activity high-alumina volcanic ash solid waste pre-ground powder are 0.5-1.5:1.

[0017] In the technical scheme of the present application, the dosage of the calcium-increasing component in step (2) is 1-5% of the sum of the mass of the carbon sequestration solid waste and the pre-micronized micro-powder of the medium-low activity high-alumina pozzolanic solid waste.

[0018] In the technical scheme of the present application, the ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material in step (2) is micronized to a specific surface area of >700 m 2 / kg and a 30 μm sieve residue of <1%.

[0019] In the technical scheme of the present application, the preparation method of the above-mentioned ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material and the application of the replacement Portland cement clinker thereof in the preparation of Portland cement or concrete.

[0020] Advantages:

[0021] (1) The present application uses the specific CO2 / Al2O3 ratio as the compounding principle to synergistically compound the carbon sequestration solid waste and the medium-low activity high-alumina pozzolanic solid waste, and adds appropriate dosages of the calcium-increasing component and the composite chemical additive component under different CO2 / Al2O3 ratios, thereby significantly improving the hydration activity of the carbon sequestration solid waste and the high-alumina pozzolanic solid waste by utilizing the synergistic activity improvement mechanism among the carbon sequestration solid waste, the medium-low activity high-alumina pozzolanic solid waste, the calcium-increasing component and the composite chemical additive, achieving the technical purpose of "1+1>2" and achieving the technical effect of preparing the ultra-high activity auxiliary cementitious material from the medium-low activity solid waste.

[0022] (2) The present application uses the medium-low activity solid waste with an activity index lower than S90 (30% dosage) as the main precursor raw material to prepare the ultra-high activity auxiliary cementitious material with an activity index of S130-S145 at a 30% dosage and an activity index greater than S120-S130 at a 50% dosage, which can greatly increase the utilization amount of the carbon sequestration solid waste and the medium-low activity high-alumina pozzolanic solid waste in the field of Portland cement and concrete products, while greatly reducing the consumption of Portland cement clinker in Portland cement and concrete products, thereby having great economic and environmental benefits.

[0023] Technical principle:

[0024] The present application utilizes the synergistic activity improvement mechanism among the carbon sequestration solid waste, the medium-low activity high-alumina pozzolanic solid waste, the calcium-increasing component and the composite chemical additive, and adopts the segmented ultra-fine grinding as the production process method, thereby achieving the technical effect of preparing the ultra-high activity auxiliary cementitious material from the medium-low activity solid waste, and the part of the technical principle is described as follows:

[0025] i. The hydration activity of carbon sequestration solid waste and low-medium activity high-alumina pozzolanic solid waste is synergistically improved: In addition to the amorphous silicon with potential hydration activity, the carbon sequestration solid waste contains a large amount of calcium carbonate which cannot effectively react with the calcium silicate mineral phase in the Portland cement clinker, resulting in a serious limitation of the activity effect of the carbon sequestration solid waste in the Portland cement system. In the Portland cement system, the low-medium activity high-alumina pozzolanic solid waste also has limited activity effect due to the difficulty of rapid and sufficient reaction of its aluminum phase. However, by compounding the carbon sequestration solid waste and the low-medium activity high-alumina pozzolanic solid waste at a specific CO2 / Al2O3 ratio, the submicron calcium carbonate in the carbon sequestration solid waste and the aluminum phase in the high-alumina pozzolanic solid waste can rapidly react in the Portland cement system, forming a large amount of crystalline hydrated products such as hydrated calcium aluminum carbonate, so that the hydration reaction activity and degree of the carbon sequestration solid waste and the high-alumina pozzolanic solid waste are greatly synergistically improved, achieving a technical effect of "1+1>2". In addition, the crystalline hydrated products such as hydrated calcium aluminum carbonate formed by the rapid reaction of the carbon sequestration solid waste and the low-medium activity high-alumina pozzolanic solid waste can effectively fill the micro voids and improve the compactness of the cement clinker, amorphous silicon in the carbon sequestration solid waste, and amorphous C-S-H gel formed by the hydration of the low-medium activity high-alumina pozzolanic solid waste, further improving the activity synergistic improvement effect of the carbon sequestration solid waste and the low-medium activity high-alumina pozzolanic solid waste.

[0026] ii. The calcium-increasing component continuously improves the long-term hydration activity of carbon sequestration solid waste and low-medium activity high-alumina pozzolanic solid waste: The process of forming product hydrated calcium aluminum carbonate by the synergistic reaction of carbon sequestration solid waste and low-medium activity high-alumina pozzolanic solid waste can significantly increase the calcium hydroxide consumption of the "portland clinker-carbon sequestration solid waste-low-medium activity high-alumina pozzolanic solid waste system", and then cause the relative lack of calcium hydroxide content in the system at long age, which ultimately significantly restricts the full play of the long-term hydration activity of the super-high activity solid waste-based carbon sequestration auxiliary cementitious material. By using an appropriate amount of calcium-increasing component and the optimal compounding of carbon sequestration solid waste-high-alumina pozzolanic solid waste with different CO2 / Al2O3 ratios, the present application promotes the full and efficient play of the hydration activity of the super-high activity solid waste-based carbon sequestration auxiliary cementitious material at different ages.

[0027] iii.The synergistic improvement of composite chemical additives on the hydration activity of ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material: The ultra-high hydration activity of the solid waste-based carbon sequestration auxiliary cementitious material is closely related to the improvement of the hydration reaction activity, the promotion of the hydration reaction process, and the improvement of the stability of the hydration product by the composite chemical additives. Based on the material characteristics and hydration principle of the ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material system, specific chemical components are further introduced based on the traditional alcohol amine additives. The specific chemical components have the following principles and effects: accelerating the generation of calcium aluminate carbonate product, improving the stability of calcium aluminate carbonate product, improving the dissolution of active components of solid waste-based carbon sequestration auxiliary cementitious material, and reducing the potential negative impact of solid waste-based carbon sequestration auxiliary cementitious material on workability. The ultra-high hydration activity of the solid waste-based carbon sequestration auxiliary cementitious material is further promoted.

[0028] iv.The synergistic improvement of the segmented ultra-fine grinding process on the hydration activity of ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material: The reaction activity of the phase can be improved to some extent by using the ultra-fine grinding process. According to the difference in hydration activity of the phase and the difference in easy grindability of the phase between the carbon sequestration solid waste and the low-activity high-alumina pozzolanic solid waste, the segmented ultra-fine grinding process is adopted. Not only can the ultra-fine grinding efficiency be improved, but also the calcium carbonate product layer and amorphous silicon product layer in the carbon sequestration solid waste can be fully stripped and dispersed, and the reaction contact area between the calcium carbonate component in the carbon sequestration solid waste and the low-activity high-alumina pozzolanic solid waste powder can be improved, thereby further improving the activity synergistic effect of the carbon sequestration solid waste and the high-alumina pozzolanic solid waste. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Process flow chart for preparing ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material by using carbon sequestration solid waste and low-activity high-alumina pozzolanic solid waste.

[0030] Figure 2 X-ray diffraction spectra of the composite portland cement obtained in the reference cement, Comparative Example 1, Comparative Example 4, Comparative Example 9, and Example 4 after hydration for 28 days.

[0031] Figure 3 Backscattered electron image of the ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material obtained in Example 1 after hydration for 28 days.

[0032] Figure 4 Backscattered electron image of the ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material obtained in Example 1 after hydration for 28 days.

[0033] Figure 5 Backscattered electron image of the ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material obtained in Example 6 after hydration for 28 days.

[0034] Figure 6 The secondary electron image of the super-high-activity solid waste-based carbon sequestration auxiliary cementitious material obtained in Example 6 after hydration for 28 days. DETAILED DESCRIPTION

[0035] The application will be further described below in conjunction with examples, but the scope of protection of the application is not limited thereto:

[0036] The key chemical composition parameters of the carbon sequestration solid waste, high-alumina pozzolanic solid waste, and composite chemical additive used in each example and comparative example are listed as follows:

[0037] The carbon sequestration waste used includes: ① carbonized converter steel slag, prepared by dry carbonization process, with a CO2 content measured by alkali asbestos absorption gravimetric method of 11.4%; ② carbonized sintered red mud, prepared by wet carbonization process, with a CO2 content measured by alkali asbestos absorption gravimetric method of 15.7%; ③ carbonized waste concrete micro powder, prepared by wet carbonization process, with a CO2 content measured by alkali asbestos absorption gravimetric method of 13.1%; and ④ carbonized magnesium slag, prepared by dry carbonization process, with a CO2 content measured by alkali asbestos absorption gravimetric method of 10.1%.

[0038] The low-to-medium-activity high-alumina pozzolanic solid waste used includes: ① fly ash, commercially available Grade II, with an Al2O3 content of 28.9 wt.%; ② calcined aluminous coal gangue, self-prepared, with an Al2O3 content of 32.7 wt.%; and ③ coal-fired furnace bottom slag, with an Al2O3 content of 27.5 wt.%. The pozzolanic tests of the above high-alumina pozzolanic solid waste are all qualified.

[0039] In the composite chemical additive used, the alcohol amine grinding aid is compounded from triisopropanolamine (Macklin, AR) and diethanol monoisopropanolamine (Macklin, AR) at a mass ratio of 1:1, polycarboxylate (Sika, 225P), aluminate, titanate, sodium aluminate, and sodium ferrite are all commercially available chemical pure products of Yonghua Chemical Co., Ltd.

[0040] Example 1

[0041] A preparation method of a super-high-activity solid waste-based carbon sequestration auxiliary cementitious material and its application, including the following steps:

[0042] (1) The calcined aluminous coal gangue is pre-ground to a specific surface area of 504 m2 / kg and a 45 μm sieve residue of 2.7%, to obtain calcined aluminous coal gangue pre-ground micro powder; during the grinding process, a composite chemical additive is added, the additive is composed of 80 parts by mass of alcohol amine grinding aid, 15 parts by mass of polycarboxylate, 0.5 parts by mass of aluminate, and 4.5 parts by mass of sodium aluminate, and the dosage of the composite chemical additive is 4 ‰ of the mass of the low-to-medium-activity high-alumina pozzolanic solid waste. 2 / kg and a 45 μm sieve residue of 2.7%, to obtain calcined aluminous coal gangue pre-ground micro powder; during the grinding process, a composite chemical additive is added, the additive is composed of 80 parts by mass of alcohol amine grinding aid, 15 parts by mass of polycarboxylate, 0.5 parts by mass of aluminate, and 4.5 parts by mass of sodium aluminate, and the dosage of the composite chemical additive is 4 ‰ of the mass of the low-to-medium-activity high-alumina pozzolanic solid waste.

[0043] (2)The carbonized converter steel slag and the calcined aluminous coal gangue pre-ground powder are proportioned with a mass ratio of CO2 / Al2O3=0.5; 1wt.% of carbide slag is added as a calcium-increasing component (the addition amount of the calcium-increasing component is 1% of the sum of the mass of the carbon sequestration solid waste and the pre-ground powder of the medium-low activity high-alumina pozzolanic solid waste, and the definition is the same as in Examples 2-11), ultrafine grinding is performed, and an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area of 714 m 2 / kg and a 30 μm residue of 0.8% is obtained.

[0044] (3)The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace 30% of cement clinker to prepare Portland cement, and the 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Admixtures”.

[0045] Example 2

[0046] A preparation method of an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material and its application, comprising the following steps:

[0047] (1)The calcined aluminous coal gangue is pre-ground to a specific surface area of 504 m 2 / kg and a 45 μm residue of 2.7%, to obtain a calcined aluminous coal gangue pre-ground powder; a composite chemical additive is added during the grinding process, and the additive is composed of 70 parts by mass of an alcohol amine grinding aid, 18 parts by mass of a polycarboxylate, 3 parts by mass of an aluminate, 6 parts by mass of sodium aluminate, and 3 parts by mass of sodium ferrite; the addition amount of the composite chemical additive is 4 ‰ of the mass of the medium-low activity high-alumina pozzolanic solid waste.

[0048] (2)The carbonized sintered red mud and the calcined aluminous coal gangue pre-ground powder are proportioned with a mass ratio of CO2 / Al2O3=0.5; 1.5wt.% of lime is added as a calcium-increasing component, ultrafine grinding is performed, and an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area of 723 m 2 / kg and a 30 μm residue of 0.8% is obtained.

[0049] (3)The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace 30% of cement clinker to prepare Portland cement, and the 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Admixtures”.

[0050] Example 3

[0051] A preparation method of an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material and its application, comprising the following steps:

[0052] (1) The calcined aluminous coal gangue is pre-ground to a specific surface area = 504 m 2 / kg and a 45 μm screen residue = 2.7%, to obtain calcined aluminous coal gangue pre-ground powder; a composite chemical additive is added during the grinding process, the additive is composed of 65 parts by mass of alcohol amine grinding aid, 25.5 parts by mass of polycarboxylate, 1.5 parts by mass of titanium acid ester, and 8 parts by mass of sodium aluminate, and the amount of the composite chemical additive is 4 ‰ of the mass of the medium-low activity high-alumina fly ash solid waste.

[0053] (2) The carbonized magnesium slag and the calcined aluminous coal gangue pre-ground powder are mixed at a mass ratio of CO2 / Al2O3 = 1; 3 wt.% of lime is added as a calcium-increasing component, ultra-fine grinding is performed, and an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area = 721 m 2 / kg and a 30 μm screen residue < 0.8% is obtained.

[0054] (3) The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace 30% of the cement clinker to prepare Portland cement, and the 28d activity index is determined according to the "GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Mixtures".

[0055] Example 4

[0056] A preparation method of an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material and its application, comprising the following steps:

[0057] (1) The fly ash is pre-ground to a specific surface area = 516 m 2 / kg and a 45 μm screen residue = 2.6%, to obtain fly ash pre-ground powder; a composite chemical additive is added during the grinding process, the additive is composed of 70 parts by mass of alcohol amine grinding aid, 20 parts by mass of polycarboxylate, 1.5 parts by mass of aluminum acid ester, and 8.5 parts by mass of sodium aluminate, and the amount of the composite chemical additive is 4 ‰ of the mass of the medium-low activity high-alumina fly ash solid waste.

[0058] (2) The carbonized converter steel slag and the fly ash pre-ground powder are mixed at a mass ratio of CO2 / Al2O3 = 1; 2 wt.% of carbide slag is added as a calcium-increasing component, ultra-fine grinding is performed, and an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area > 714 m 2 / kg and a 30 μm screen residue < 0.9% is obtained.

[0059] (3) The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace 30% of the cement clinker to prepare Portland cement, and the 28d activity index is determined according to the "GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Mixtures".

[0060] Example 5

[0061] A preparation method of a super-high-activity solid-waste-based carbon fixation auxiliary cementitious material and its application, comprising the following steps:

[0062] (1) The calcined aluminous coal gangue is pre-ground to a specific surface area of 504 m 2 / kg and a 45 μm sieve residue of 2.7%, to obtain calcined aluminous coal gangue pre-ground powder; during the grinding process, a composite chemical additive is added, the additive is composed of 52.5 parts by mass of an alcohol amine grinding aid, 35 parts by mass of a polycarboxylate, 2.5 parts by mass of a titanate, and 10 parts by mass of sodium aluminate, and the dosage of the composite chemical additive is 4 ‰ of the mass of the medium-low-activity high-alumina pozzolanic solid waste.

[0063] (2) The carbonized waste concrete powder and the calcined aluminous coal gangue pre-ground powder are proportioned at a mass ratio of CO2 / Al2O3=1; at the same time, 3.5 wt.% of calcium carbide slag is added as a calcium-increasing component, superfine grinding is performed, and a super-high-activity solid-waste-based carbon fixation auxiliary cementitious material with a specific surface area of 734 m 2 / kg and a 30 μm sieve residue of 0.8% is obtained.

[0064] (3) The obtained super-high-activity solid-waste-based carbon fixation auxiliary cementitious material is used to replace cement clinker at a proportion of 30% to prepare Portland cement, and the 28d activity index is determined according to the "GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Admixtures".

[0065] Example 6

[0066] A preparation method of a super-high-activity solid-waste-based carbon fixation auxiliary cementitious material and its application, comprising the following steps:

[0067] (1) The calcined aluminous coal gangue is pre-ground to a specific surface area of 504 m 2 / kg and a 45 μm sieve residue of 2.7%, to obtain calcined aluminous coal gangue pre-ground powder; during the grinding process, a composite chemical additive is added, the additive is composed of 52.5 parts by mass of an alcohol amine grinding aid, 35 parts by mass of a polycarboxylate, 2.5 parts by mass of a titanate, and 10 parts by mass of sodium aluminate, and the dosage of the composite chemical additive is 4 ‰ of the mass of the medium-low-activity high-alumina pozzolanic solid waste.

[0068] (2) The carbonized converter steel slag and the calcined aluminous coal gangue pre-ground powder are proportioned at a mass ratio of CO2 / Al2O3=1.5; at the same time, 3.5 wt.% of calcium carbide slag is added as a calcium-increasing component, superfine grinding is performed, and a super-high-activity solid-waste-based carbon fixation auxiliary cementitious material with a specific surface area of 734 m 2 / kg and a 30 μm sieve residue of 0.8% is obtained.

[0069] (3) The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace cement clinker by 30% to prepare Portland cement, and the 28d activity index is determined according to the method of GB / T 12957-2005 Activity Test Method for Industrial Waste Residues Used as Cement Admixtures.

[0070] Example 7

[0071] A preparation method of an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material and its application, comprising the following steps:

[0072] (1) The coal-fired furnace bottom slag is pre-ground to a specific surface area of 511 m 2 / kg and a 45 μm sieve residue of 2.6%, to obtain fly ash pre-ground powder; a composite chemical additive is added during the grinding process, and the additive is composed of 60 parts by mass of an alcohol amine grinding aid, 22 parts by mass of a polycarboxylate, 3 parts by mass of an aluminate, and 15 parts by mass of sodium aluminate, and the dosage of the composite chemical additive is 4 ‰ of the mass of the medium-low activity high-alumina pozzolanic solid waste.

[0073] (2) The carbonized sintered red mud and the coal-fired furnace bottom slag pre-ground powder are proportioned at a mass ratio of CO2 / Al2O3=1.5; 4wt.% of calcium carbide slag is added as a calcium-increasing component, ultra-fine grinding is performed, and an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area of 733 m 2 / kg and a 30 μm sieve residue of 0.8% is obtained.

[0074] (3) The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace cement clinker by 30% to prepare Portland cement, and the 28d activity index is determined according to the method of GB / T 12957-2005 Activity Test Method for Industrial Waste Residues Used as Cement Admixtures.

[0075] Example 8

[0076] A preparation method of an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material and its application, comprising the following steps:

[0077] (1) The calcined aluminum coal gangue is pre-ground to a specific surface area of 504 m 2 / kg and a 45 μm sieve residue of 2.7%, to obtain calcined aluminum coal gangue pre-ground powder; a composite chemical additive is added during the grinding process, and the additive is composed of 40 parts by mass of an alcohol amine grinding aid, 42 parts by mass of a polycarboxylate, 3.5 parts by mass of an aluminate, 10 parts by mass of sodium aluminate, and 4.5 parts by mass of sodium ferrite, and the dosage of the composite chemical additive is 4 ‰ of the mass of the medium-low activity high-alumina pozzolanic solid waste.

[0078] (2) The carbonized waste concrete micro powder is mixed with the calcined aluminum coal gangue pre-ground powder at a mass ratio of CO2 / Al2O3=1.5, and 5wt.% of lime is added as a calcium-increasing component, superfine grinding is performed, and an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area of 728m 2 / kg and a 30μm residue of 0.8% is obtained.

[0079] (3) The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace cement clinker at a proportion of 30% to prepare Portland cement, and a 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Admixtures”.

[0080] Example 9

[0081] A preparation method and application of an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material, comprising the following steps:

[0082] (1) The calcined aluminum coal gangue is pre-ground to a specific surface area of 504m 2 / kg and a 45μm residue of 2.7%, to obtain calcined aluminum coal gangue pre-ground powder. During the grinding process, a composite chemical additive is added, which is composed of 65 parts by mass of an alcohol amine grinding aid, 25.5 parts by mass of a polycarboxylate, 1.5 parts by mass of an aluminate, and 8 parts by mass of sodium aluminate. The dosage of the composite chemical additive is 4‰ of the mass of the low-to-medium activity high-alumina fly ash solid waste.

[0083] (2) The carbonized converter steel slag is mixed with the calcined aluminum coal gangue pre-ground powder at a mass ratio of CO2 / Al2O3=1, and 3wt.% of lime is added as a calcium-increasing component, superfine grinding is performed, and an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area of 740m 2 / kg and a 30μm residue of 0.7% is obtained.

[0084] (3) The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace cement clinker at a proportion of 50% to prepare Portland cement, and a 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Admixtures”.

[0085] Example 10

[0086] A preparation method and application of an ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material, comprising the following steps:

[0087] (1) The fly ash is pre-ground to a specific surface area of 516m 2 / kg and 45 μm residue = 2.6%, to obtain fly ash pre-grinding powder; add composite chemical additives during grinding, the additives are composed of 70 parts by mass of alcohol amine grinding aid, 20 parts by mass of polycarboxylate, 1.5 parts by mass of aluminate, and 8.5 parts by mass of sodium aluminate, and the dosage of the composite chemical additives is 4 ‰ of the mass of the medium-low activity high-alumina fly ash solid waste.

[0088] (2) The carbonized sintered red mud and the fly ash pre-grinding powder are mixed at a mass ratio of CO2 / Al2O3 = 1; 2 wt.% of calcium carbide slag is added as a calcium-increasing component, superfine grinding is performed, and a super-high-activity solid-waste-based carbon sequestration auxiliary cementitious material with a specific surface area = 768 m 2 / kg and 30 μm residue = 0.5% is obtained.

[0089] (3) The obtained super-high-activity solid-waste-based carbon sequestration auxiliary cementitious material is used to replace 50% of cement clinker to prepare Portland cement, and the 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Mixtures”.

[0090] Example 11

[0091] A preparation method of a super-high-activity solid-waste-based carbon sequestration auxiliary cementitious material and its application, comprising the following steps:

[0092] (1) The calcined aluminum coal gangue is pre-ground to a specific surface area = 504 m 2 / kg and 45 μm residue = 2.7%, to obtain calcined aluminum coal gangue pre-grinding powder; add composite chemical additives during grinding, the additives are composed of 52.5 parts by mass of alcohol amine grinding aid, 35 parts by mass of polycarboxylate, 2.5 parts by mass of aluminate, and 10 parts by mass of sodium aluminate, and the dosage of the composite chemical additives is 4 ‰ of the mass of the medium-low activity high-alumina fly ash solid waste.

[0093] (2) The carbonized sintered red mud and the calcined aluminum coal gangue pre-grinding powder are mixed at a mass ratio of CO2 / Al2O3 = 1; 3.5 wt.% of calcium carbide slag is added as a calcium-increasing component, superfine grinding is performed, and a super-high-activity solid-waste-based carbon sequestration auxiliary cementitious material with a specific surface area = 752 m 2 / kg and 30 μm residue = 0.6% is obtained.

[0094] (3) The obtained super-high-activity solid-waste-based carbon sequestration auxiliary cementitious material is used to replace 50% of cement clinker to prepare Portland cement, and the 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Mixtures”.

[0095] Comparative Example 1

[0096] Carbonated solid waste, carbonated converter steel slag, is ground to a specific surface area = 743 m 2 / kg and 30 μm residue = 0.6%, to prepare carbonated steel slag micro-powder; the obtained carbonated steel slag micro-powder is used to replace cement clinker by 30% to prepare Portland cement, and 28d activity index is determined according to "GB / T 12957-2005 Activity Test Method of Industrial Waste Residue for Cement Admixtures".

[0097] Comparative Example 2

[0098] Carbonated solid waste, carbonated sintered red mud, is ground to a specific surface area = 725 m 2 / kg and 30 μm residue = 0.8%, to prepare carbonated sintered red mud micro-powder; the obtained carbonated sintered red mud micro-powder is used to replace cement clinker by 30% to prepare Portland cement, and 28d activity index is determined according to "GB / T 12957-2005 Activity Test Method of Industrial Waste Residue for Cement Admixtures".

[0099] Comparative Example 3

[0100] Carbonated solid waste, carbonated waste concrete, is ground to a specific surface area = 733 m 2 / kg and 30 μm residue = 0.6%, to prepare carbonated waste concrete micro-powder; the obtained carbonated waste concrete micro-powder is used to replace cement clinker by 30% to prepare Portland cement, and 28d activity index is determined according to "GB / T 12957-2005 Activity Test Method of Industrial Waste Residue for Cement Admixtures"

[0101]

[0102] Comparative Example 4

[0103] Medium-low activity high-alumina pozzolanic solid waste, fly ash (grade II), is used to replace cement clinker by 30% to prepare Portland cement, and 28d activity index is determined according to "GB / T 12957-2005 Activity Test Method of Industrial Waste Residue for Cement Admixtures"

[0104]

[0105] Comparative Example 5

[0106] Medium-low activity high-alumina pozzolanic solid waste, coal-fired furnace bottom slag, is ground to a specific surface area = 704 m 2 / kg and 30 μm residue = 1.0%, and is used to replace cement clinker by 30% to prepare Portland cement, and 28d activity index is determined according to "GB / T

[0107] 12957-2005 Activity Test Method of Industrial Waste Residue for Cement Admixtures".​​

[0108] Comparative Example 6

[0109] The medium and low activity high alumina volcanic ash solid waste - calcined alumina coal gangue, is ground to a specific surface area of ​​715m 2 / kg and 30μm sieve residue = 0.8%, and 30% of the cement clinker was substituted to prepare silicate cement, and the

[0110] 12957-2005 Test method for the activity of industrial waste residue used in cement admixtures” was used to determine the 28-day activity index.

[0111] Comparative Example 7

[0112] (1) Pre-grind the calcined aluminous coal gangue to a specific surface area of ​​504m 2 / kg and 45μm sieve residue = 2.7%, to obtain calcined aluminum gangue pre-ground fine powder; during the grinding process, only alcoholamine grinding aids are added, and the amount of alcoholamine grinding aids is 4‰.

[0113] (2) Carbonized converter slag and calcined aluminous gangue pre-ground powder were mixed with a mass ratio of CO2 / Al2O3 = 0.5; at the same time, no calcium-enhancing component was added, and ultrafine grinding was performed to obtain a specific surface area of ​​706m 2 / kg and 30μm sieve residue = 0.9% solid waste-based carbon fixation auxiliary cementitious material.

[0114] (3) The obtained solid waste-based carbon fixation auxiliary cementitious material was used to replace cement clinker at a ratio of 30% to prepare silicate cement, and the 28-day activity index was determined in accordance with "GB / T 12957-2005 Test method for activity of industrial waste residue used in cement admixtures".

[0115] Comparative Example 8

[0116] (1) Pre-grind the fly ash to a specific surface area of ​​516m 2 / kg and 45μm sieve residue = 2.6%, to obtain pre-ground fly ash fine powder; during the grinding process, only alcoholamine grinding aids were added, and the amount of alcoholamine grinding aids was 4‰.

[0117] (2) Carbonization sintering red mud and fly ash pre-ground powder were mixed at a mass ratio of CO2 / Al2O3 = 0.5; at the same time, no calcium-enhancing component was added, and ultrafine grinding was performed to obtain a specific surface area of ​​722m 2 / kg and 30μm sieve residue = 0.9% ultra-high activity solid waste-based carbon fixation auxiliary cementitious material.

[0118] (3) The obtained super-high-activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace cement clinker by 30% to prepare Portland cement, and the 28d activity index is determined according to the method of GB / T 12957-2005 Activity Test Method for Industrial Waste Residues Used as Cement Admixtures.

[0119] Comparative Example 9

[0120] (1) The calcined aluminous coal gangue is pre-ground to a specific surface area of 516 m 2 / kg and a 45 μm sieve residue of 2.6%, to obtain a pre-ground micro-powder of the calcined aluminous coal gangue; only an alcohol amine grinding aid is added during the grinding process, and the alcohol amine grinding aid is added in an amount of 4 ‰.

[0121] (2) The carbonized converter steel slag and the pre-ground micro-powder of the fly ash are proportioned at a mass ratio of CO2 / Al2O3 = 1; no calcium-increasing component is added, and superfine grinding is performed to obtain a solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area of 728 m 2 / kg and a 30 μm sieve residue of 0.8%.

[0122] (3) The obtained solid waste-based carbon sequestration auxiliary cementitious material is used to replace cement clinker by 30% to prepare Portland cement, and the 28d activity index is determined according to the method of GB / T 12957-2005 Activity Test Method for Industrial Waste Residues Used as Cement Admixtures.

[0123] Comparative Example 10

[0124] (1) The coal-fired furnace bottom slag is pre-ground to a specific surface area of 511 m 2 / kg and a 45 μm sieve residue of 2.6%, to obtain a pre-ground micro-powder of the coal-fired furnace bottom slag; only an alcohol amine grinding aid is added during the grinding process, and the alcohol amine grinding aid is added in an amount of 4 ‰.

[0125] (2) The carbonized sintering method red mud and the pre-ground micro-powder of the coal-fired furnace bottom slag are proportioned at a mass ratio of CO2 / Al2O3 = 1.5; no calcium-increasing component is added, and superfine grinding is performed to obtain a solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area of 715 m 2 / kg and a 30 μm sieve residue of 0.8%.

[0126] (3) The obtained solid waste-based carbon sequestration auxiliary cementitious material is used to replace cement clinker by 30% to prepare Portland cement, and the 28d activity index is determined according to the method of GB / T 12957-2005 Activity Test Method for Industrial Waste Residues Used as Cement Admixtures.

[0127] Comparative Example 11

[0128] (1) The calcined aluminous coal gangue is pre-ground to a specific surface area of 362 m 2 / kg and 45 μm residue = 6.6%, to obtain the calcined aluminous coal gangue pre-grinding coarse powder; a composite chemical additive is added during the grinding process, the additive is composed of 80 parts by mass of an alcohol amine grinding aid, 15 parts by mass of a polycarboxylate, 0.5 parts by mass of an aluminate, and 4.5 parts by mass of sodium aluminate, and the dosage of the composite chemical additive is 4 ‰ of the mass of the low-to-medium activity high-alumina pozzolanic solid waste.

[0129] (2) The carbonized converter steel slag and the calcined aluminous coal gangue pre-grinding coarse powder are proportioned at a mass ratio of CO2 / Al2O3 = 0.5; 1 wt.% of carbide slag is added as a calcium-increasing component, and a solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area = 544 m 2 / kg and 30 μm residue

[0130] = 9.6% is further obtained.

[0131] (3) The obtained solid waste-based carbon sequestration auxiliary cementitious material is used to replace 30% of cement clinker to prepare Portland cement, and the 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Mixtures”.

[0132] Comparative Example 12

[0133] (1) The fly ash is pre-ground to a specific surface area = 371 m 2 / kg and 45 μm residue = 5.2%, to obtain fly ash pre-grinding coarse powder; a composite chemical additive is added during the grinding process, the additive is composed of 70 parts by mass of an alcohol amine grinding aid, 20 parts by mass of a polycarboxylate, 1.5 parts by mass of an aluminate, and 8.5 parts by mass of sodium aluminate, and the dosage of the composite chemical additive is 4 ‰ of the mass of the low-to-medium activity high-alumina pozzolanic solid waste.

[0134] (2) The carbonized sintered red mud and the fly ash pre-grinding coarse powder are proportioned at a mass ratio of CO2 / Al2O3 = 1; 2 wt.% of carbide slag is added as a calcium-increasing component, and ultrafine grinding is performed to obtain a solid waste-based carbon sequestration auxiliary cementitious material with a specific surface area = 526 m 2 / kg and 30 μm residue

[0135] = 9.7%.

[0136] (3) The obtained ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material is used to replace 50% of cement clinker to prepare Portland cement, and the 28d activity index is determined according to the “GB / T 12957-2005 Industrial Waste Residue Activity Test Method for Cement Mixtures”.

[0137] According to GB / T 12957-2005, the activity index of the auxiliary cementitious material prepared in Examples 1-27 and Comparative Examples 1-6 was tested at 28 days. The material ratio and the activity index are shown in Table 1.

[0138] Table 1

[0139]

[0140]

[0141] As can be seen from the experimental results of each example and comparative example in Table 1, by using the low-activity carbon fixation solid waste (Comparative Examples 1-3, 30% content, activity index S84-S94) and high-aluminum pozzolanic solid waste (Comparative Examples 4-6, 30% content, activity index S82-S92) as raw material components, and by optimizing the material ratio (CO2 / Al2O3), adding calcium components, compounding composite chemical additives, and segmenting superfine grinding, an ultra-high-activity solid-waste-based carbon fixation auxiliary cementitious material with an activity index much higher than that of single carbon fixation solid waste component or single high-aluminum pozzolanic solid waste component can be prepared. By using the optimal technical solution of the present application, the 28d activity index of the ultra-high-activity solid-waste-based carbon fixation auxiliary cementitious material can reach S140 grade (Examples 2-5) when 30% of cement clinker is replaced; the 28d activity index of the ultra-high-activity solid-waste-based carbon fixation auxiliary cementitious material can reach S120-S130 (Examples 9-11) when 50% of cement clinker is replaced, and the hydration activity is much higher than the highest activity index grade (S105 grade, GB / T 18046-2017 Granulated blast furnace slag for use in cement, mortar and concrete) in the current national standard.

[0142] By comparing each example in Table 1 with the comparative examples, it is also clear that: ① The compounding ratio (CO2 / Al2O3) of the carbon sequestration solid waste and the high-aluminum volcanic ash solid waste has a significant influence on the hydration activity of the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material, and the optimal compounding ratio is CO2 / Al2O3 = 1; ② Compared with traditional alcohol amine grinding aids, the composite chemical additive used in the present application can further improve the hydration activity of the compounded solid-waste-based carbon sequestration auxiliary cementitious material by promoting the formation of hydrated calcium carbonate aluminates and improving the stability of the hydrated calcium carbonate aluminates; ③ The calcium-increasing component also has a significant positive influence on the improvement of the 28d activity index of the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material; ④ Grinding to the specific particle surface area and particle size range defined in the technical solution is a necessary condition for achieving the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material. It can be seen that in the technical solution of the present application, the technical means of optimizing the compounding ratio (CO2 / Al2O3), adding the calcium-increasing component, compounding the composite chemical additive, and the optimal particle surface area and particle size range are all necessary technical means for achieving the preparation of the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material.

[0143] In addition, to verify the activity improvement mechanism of the ultra-high-activity solid-waste-based carbon sequestration mineral admixture, the inventors also analyzed and characterized the hydration reaction mineral phase composition and microstructure morphology of the ultra-high-activity solid-waste-based carbon sequestration mineral admixture for some examples. Figure 2 The X-ray diffraction spectra of the composite portland cement obtained in Comparative Example 1, Comparative Example 4, Comparative Example 9, and Example 4 after hydration for 28d are shown in Figure 2. Figure 2 It can be seen that, compared with Comparative Example 1 and Comparative Example 4, the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material (Example 4) forms a large amount of hydrated calcium carbonate aluminates (MC) during hydration in the cement system, fully utilizes the activity effect of the calcium carbonate component (CC), and effectively improves the hydration activity of the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material. By comparing Comparative Example 9 with Example 4, it can be seen that the addition of the composite chemical additive further promotes the formation of hydrated calcium carbonate aluminates (MC) and increases the content of hydrated calcium carbonate aluminates (MC). In addition, by comparing Example 4 with Comparative Example 9, it can be seen that the introduction of the calcium-increasing component effectively increases the calcium hydroxide content in the long-term cementitious material system, which can effectively avoid the influence of the relative lack of alkalinity of the cementitious material system on the sustained exertion of the hydration activity of the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material. The ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material obtained in Example 1 and Example 6 was hydrated for 28d, and the samples were observed by backscattered electron image or secondary electron image, and the results are shown in Figure 3. Figures 3-6 As shown in Figure 3, in the backscattered electron image of the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material obtained in Example 1 and hydrated for 28d (3000 times), Figure 3 As shown in Figure 3, in the backscattered electron image of the ultra-high-activity solid-waste-based carbon sequestration auxiliary cementitious material obtained in Example 1 and hydrated for 28d (3000 times), Figure 4The backscattered electron image (20000 times) of the super-high-activity solid waste-based carbon sequestration auxiliary cementitious material obtained in Example 1 after hydration for 28 days. Figure 5 The backscattered electron image (20000 times) of the super-high-activity solid waste-based carbon sequestration auxiliary cementitious material obtained in Example 6 after hydration for 28 days, Figure 6 The secondary electron image (100000 times) and EDS spectrum of the super-high-activity solid waste-based carbon sequestration auxiliary cementitious material obtained in Example 6 after hydration for 28 days. Figures 3-6 It can be seen that a large amount of hydrated calcium carboaluminate product is formed by the reaction of the super-high-activity solid waste-based carbon sequestration auxiliary cementitious material, which is one of the important reasons why the super-high-activity solid waste-based carbon sequestration auxiliary cementitious material has super-high hydration activity.

[0144] The above examples show that by using the technical solutions of the present application, such as optimizing the proportion of ingredients (CO2 / Al2O3), adding calcium-increasing components, compounding composite chemical additives, and segmenting superfine grinding, the hydration activity of low-activity carbon sequestration solid waste and high-alumina pozzolanic solid waste can be effectively improved, and a super-high-activity solid waste-based carbon sequestration auxiliary cementitious material with an activity index of S130-S145 grade (30% blending amount) can be prepared. The technical solutions of the present application can greatly improve the application value of low-activity carbon sequestration solid waste and high-alumina pozzolanic solid waste in cement and concrete materials.

[0145] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A method for preparing an ultra-high-activity solid-waste-based carbon sequestration-assisted cementitious material, characterized in that: The steps of the method are: (1) pre-grinding the low-medium activity high-alumina pozzolanic solid waste to obtain low-medium activity high-alumina pozzolanic solid waste pre-grounding micro-powder, and adding corresponding composite chemical additives during the pre-grinding process; in step (1), the low-medium activity high-alumina pozzolanic solid waste is one or more of fly ash, coal-fired furnace bottom slag, calcined aluminous coal gangue, and calcined clay rock coal gangue; (2) mixing and ultra-fine grinding the carbon sequestration solid waste, the low-medium activity high-alumina pozzolanic solid waste pre-grounding micro-powder, and the calcium-increasing component to a predetermined particle size range, to obtain the ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material; the carbon sequestration solid waste in step (2) is one or more of carbonized steel slag, carbonized sintered red mud, carbonized magnesium slag, and carbonized waste concrete micro-powder; the mass ratio of the carbon sequestration solid waste to the low-medium activity high-alumina pozzolanic solid waste pre-grounding micro-powder in step (2) is 0.5-1.5:1, with the mass ratio of CO2 in the carbon sequestration solid waste to Al2O3 in the low-medium activity high-alumina pozzolanic solid waste pre-grounding micro-powder being 0.5-1.5:1; The predetermined particle size range is 30 μm residue on sieve < 1% and specific surface area > 700 m 2 / kg 。 2. The production method according to claim 1, characterized by, the Al2O3 content of the low-medium activity high-alumina pozzolanic solid waste is ≥25wt.%, and the low-medium activity high-alumina pozzolanic solid waste passes the pozzolanic test.

3. The preparation method according to claim 1, characterized in that the composite chemical additives added during the pre-grinding process in step (1) are composed of 40-85 parts by mass of alcohol amine grinding aids, 10-45 parts by mass of polycarboxylate, 0.1-3.5 parts by mass of aluminum or titanium acid ester, and 4-15 parts by mass of sodium aluminate and / or sodium ferrite; the amount of the composite chemical additives is 2-8 ‰ of the mass of the low-medium activity high-alumina pozzolanic solid waste.

4. The method of claim 1, wherein, In the step (1), the obtained medium-low activity high-alumina-pozzolanic solid waste pre-grinding micro-powder has a specific surface area of >500 m 2 / kg and a 45 μm sieve residue of <3%.

5. The preparation method according to claim 1, characterized in that The above-mentioned carbon sequestration solid waste is obtained by carbonizing steel slag, sintered red mud, magnesium slag, and waste concrete micro-powder through dry or wet CO2 capture process, and the CO2 determination value of the carbon sequestration solid waste by the asbestosis absorption gravimetric method is ≥10wt.%, and the carbon component in the carbon sequestration solid waste exists in the form of calcite-type or aragonite-type calcium carbonate.

6. The method of claim 1, wherein, The calcium-increasing component in step (2) is one or more of calcium carbide slag and lime.

7. The preparation method according to claim 1, characterized in that The amount of the calcium-increasing component in step (2) is 1-5% of the sum of the mass of the carbon sequestration solid waste and the mass of the low-medium activity high-alumina pozzolanic solid waste pre-grounding micro-powder.

8. Application of the ultra-high activity solid waste-based carbon sequestration auxiliary cementitious material prepared by the method of any one of claims 1-7 to replace silicate cement clinker in the preparation of silicate cement or concrete.

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