Environment-friendly solid waste-based cementing material and preparation method thereof

Abstract

The invention discloses an environment-friendly solid waste-based cementing material and a preparation method thereof, and relates to the technical field of constructional engineering, the environment-friendly solid waste-based cementing material comprises the following components: 30-60 parts of granulated blast furnace slag, 20-50 parts of steel slag, 20-25 parts of industrial byproduct gypsum and 10-20 parts of other industrial solid wastes for 42.5 grade and 32.5 grade; and for the 22.5 grade, 20-30 parts of granulated blast furnace slag, 30-60 parts of steel slag, 20-30 parts of industrial byproduct gypsum and 20-30 parts of other industrial solid wastes are used. According to the environment-friendly solid-waste-based cementing material and the preparation method thereof, the environment-friendly solid-waste-based cementing material meeting different strength grade requirements can be produced, traditional common industrial solid waste is utilized, and other valuable industrial solid waste such as lithium slag, ammonia alkali white mud and salty mud can be effectively utilized, so that waste of the resources is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of construction engineering, and in particular to an environmentally friendly solid waste-based cementitious material and a preparation method thereof. Background Art

[0002] Solid waste-based cementitious materials are hydraulic cementitious materials made from solid waste as raw materials, which are processed and ground into fine powder and then prepared in a certain proportion. It uses the mutual synergistic stimulation and mechanical activation between industrial solid wastes to form hydraulic cementitious properties. This material generally does not add cement clinker, nor does it use caustic soda as an activator. It is an eco-friendly green cementitious material with significant environmental, economic and social benefits. It is of great significance to promote the resource utilization of industrial solid waste and the development of low-carbon building materials in my country.

[0003] For example, the patent document with the publication number CN117466556A discloses a solid waste-based cementitious material. The invention provides a solid waste-based cementitious material, which is composed entirely of solid waste materials. It not only solves the problem of factory waste, but also reduces the cost for concrete enterprises. It has low hydration heat, small shrinkage, and high later strength. In addition, the invention is a clinker-free cementitious material. It can be used without cement or with a small amount of cement in the configuration of concrete. It is a new type of material that reaches or exceeds the existing cementitious material. It has good construction performance, volume stability and durability. It solves the harmless treatment of solid waste materials in production enterprises and forms products for application in cement products and concrete.

[0004] However, in the prior art, the preparation of solid waste-based cementitious materials is often limited to traditional common industrial solid wastes such as blast furnace slag, steel slag, and industrial by-product gypsum, while ignoring other valuable industrial solid wastes such as lithium slag, ammonia-alkali white mud, salt mud, and oil shale slag. These industrial solid wastes contain a large amount of potential cementitious components and other useful substances. If they are not effectively utilized, it will not only lead to the waste of these resources, but also mean that other treatment methods need to be found to treat them, such as landfill or incineration. Landfill may cause soil and groundwater pollution, and incineration may produce harmful gases and particulate matter, thereby causing greater pressure on the environment. In addition, being limited to the utilization of traditional solid wastes also limits the innovation and development of solid waste-based cementitious material preparation technology, which is not conducive to promoting the research and development and optimization of related technologies, nor is it conducive to improving the performance and application scope of materials.

[0005] Therefore, it is urgent to improve this shortcoming. The present invention studies and improves the existing technology and its shortcomings, and provides an environmentally friendly solid waste-based cementitious material and a preparation method thereof. Summary of the invention

[0006] The object of the present invention is to provide an environmentally friendly solid waste-based cementitious material and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] On the one hand, an environmentally friendly solid waste-based cementitious material is provided, comprising components: granulated blast furnace slag (main silicon-aluminum raw material), steel slag (iron raw material and alkaline oxide source), industrial by-product gypsum (sulfate raw material, which helps to adjust the setting time and strength of the material), and other industrial solid wastes. The solid waste-based cementitious material is divided into 42.5 grades, 32.5 grades and 22.5 grades according to the strength grade, and the mass percentages of the components of the solid waste-based cementitious materials of different grades are as follows:

[0009] For grades 42.5 and 32.5, 30-60 parts of granulated blast furnace slag, 20-50 parts of steel slag, 20-25 parts of industrial by-product gypsum, and 10-20 parts of other industrial solid waste;

[0010] For level 22.5, 20-30 parts of granulated blast furnace slag, 30-60 parts of steel slag, 20-30 parts of industrial by-product gypsum, and 20-30 parts of other industrial solid waste.

[0011] Furthermore, the particle size of the granulated blast furnace slag is in the range of 0.1 to 0.5 mm.

[0012] Furthermore, the other industrial solid wastes include lithium slag, ammonia-alkali white mud, salt mud, oil shale slag, and silicon-manganese slag, and the mass ratio of lithium slag, ammonia-alkali white mud, salt mud, oil shale slag, and silicon-manganese slag is 8:5:3:2:2. The generation pathways of the other industrial solid wastes are as follows:

[0013] Lithium slag: solid waste generated during the extraction of lithium and its compounds from lithium-containing ores such as spodumene and lepidolite; in the preparation of solid waste-based cementitious materials, lithium slag is used as an auxiliary cementitious material, and its active components can undergo secondary hydration reaction with cement hydration product Ca(OH)2 to generate a large amount of CSH gel, thereby improving the mechanical strength of cement.

[0014] Ammonia-soda mud: The waste residue generated in the mother liquor distillation process, distillation supernatant liquid recycling process and equipment cleaning process of Solvay's soda ash production process is a solid waste mainly composed of calcium carbonate, magnesium hydroxide and calcium sulfate. In the preparation of solid waste-based cementitious materials, ammonia-soda mud is used as a calcium raw material and reacts with siliceous and aluminum raw materials (such as granulated blast furnace slag) to form hydration products such as hydrated calcium silicate, thereby contributing to the strength development of the material.

[0015] Salt mud: solid waste discharged during the refining of brine in the process of producing soda ash using salt as the main raw material. Its main components are calcium sulfate, magnesium hydroxide and calcium carbonate. When preparing solid waste-based cementitious materials, salt mud is used as a filler or regulator, but its addition amount must strictly follow the formula ratio to avoid adverse effects on the performance of the material.

[0016] Oil shale slag: solid waste with silicon dioxide as the main component discharged from oil shale during refining or medium-to-high temperature heating; in the preparation of solid waste-based cementitious materials, oil shale slag is used as a siliceous and aluminous raw material, reacting with calcium raw materials (such as steel slag) to form hydration products such as hydrated calcium silicate.

[0017] Silicon manganese slag: solid waste mainly in a glassy state after water quenching and granulation of the molten slag of silicon manganese iron alloy; in the preparation of solid waste-based cementitious materials, silicon manganese slag is used as a siliceous raw material and reacts with calcium and aluminum raw materials to form hydration products such as hydrated calcium silicate.

[0018] Furthermore, the physical and chemical property requirements of the solid waste-based cementitious materials include fineness, water content, setting time, sulfur trioxide, chloride ions, stability, flexural strength, and compressive strength, and there are differences in the physical and chemical property requirements of solid waste-based cementitious materials of different grades.

[0019] Furthermore, the physical and chemical performance requirements of the solid waste-based cementitious materials of different grades include the following similarities:

[0020] Fineness: 45μm square hole sieve residue ≤12.0%;

[0021] Water content: ≤1.0%;

[0022] Chloride ion: mass fraction ≤ 0.1 a %;

[0023] Stability: qualified by boiling method, ≤0.50% by pressure steaming method, qualified by immersion method.

[0024] Furthermore, the physical and chemical performance requirements of the solid waste-based cementitious materials of different grades include the following differences:

[0025] Setting time: initial setting time: 42.5 level, 32.5 level ≥ 45min; 22.5 level ≥ 150min;

[0026] Final setting time: 42.5 level, 32.5 level ≤ 600min; 22.5 level ≤ 1440min;

[0027] Sulfur trioxide: the mass fraction of 42.5 and 32.5 grades is ≤12.0%, the mass fraction of 22.5 grade is ≤16.0%;

[0028] Flexural strength: for grade 42.5, 3d ≥ 3.0MPa, 7d none, 28d ≥ 7.5MPa;

[0029] For level 32.5, 3d≥2.0MPa, 7dNone, 28d≥5.5MPa;

[0030] For level 22.5, 3d none, 7d ≥ 2.0MPa, 28d ≥ 3.5MPa;

[0031] Compressive strength: for grade 42.5, 3d ≥ 15.0MPa, 7d none, 28d ≥ 42.5MPa;

[0032] For level 32.5, 3d≥10.0MPa, 7dNone, 28d≥32.5MPa;

[0033] For level 22.5, 3d: none, 7d≥7.0MPa, 28d≥22.5MPa.

[0034] Furthermore, the marking of the solid waste-based cementitious material consists of three parts: a name code, a classification code and this document number, wherein the format of the this document number is T / CECS XXXX-20XX, and the name code is GC; the classification code complies with the strength grade of the solid waste-based cementitious material, specifically: 42.5 grade is marked as 42.5, 32.5 grade is marked as 32.5, and 22.5 grade is marked as 22.5.

[0035] On the other hand, a method for preparing an environmentally friendly solid waste-based cementitious material is provided, which is applied to an environmentally friendly solid waste-based cementitious material as described above, comprising the following steps:

[0036] S1. Raw material preparation: Pre-treat granulated blast furnace slag, steel slag, industrial by-product gypsum and other industrial solid wastes to remove impurities, adjust particle size distribution and improve the uniformity and activity of raw materials;

[0037] S2. Batching and mixing: According to the formula requirements, the pretreated raw materials are batched in proportion and mixed evenly;

[0038] S3, grinding: the mixed raw materials are sent to the mill for grinding to obtain the required fineness to ensure its hydration reaction speed and strength development;

[0039] S4. Homogenization: The ground material is homogenized to make the particle size distribution of the material more uniform, so as to eliminate the influence of the particle size difference caused by the grinding process on the material performance;

[0040] S5. Finished product inspection and packaging: The finished product will be inspected for quality, including fineness, setting time, stability and other indicators. After passing the inspection, the finished product will be packaged and marked for transportation and use.

[0041] Furthermore, in step S1, the pretreatment process of each raw material is as follows:

[0042] 1) Granulated blast furnace slag: The slag is crushed into a particle size of 0.1-0.5 mm by mechanical crushing, and the coarse and fine particles are removed by screening to meet the particle size requirements of the granulated slag. Then, the iron impurities are removed by magnetic separation, and the slag is activated by high-fine grinding or adding activators to improve its activity so that it can better participate in the formation of cementitious materials;

[0043] 2) Steel slag: After crushing, the metal iron and other impurities in the steel slag are removed by magnetic separation and air separation, and then the steel slag is aged to stabilize its performance and reduce fluctuations in subsequent processing;

[0044] 3) Industrial by-product gypsum: first remove impurities such as soil and stones from the gypsum, then crush and grind the gypsum to the required fineness, and adjust the moisture content of the gypsum as needed to ensure its compatibility with other raw materials;

[0045] 4) Other industrial solid waste:

[0046] Lithium slag: After crushing and screening, the particle size distribution that meets the requirements is obtained, and the lithium slag is chemically treated to remove harmful substances or improve its activity;

[0047] Ammonia-soda white mud: After dehydration treatment, excess water is removed, and the white mud is crushed and ground to the required fineness, and then impurities and pollutants in the white mud are removed and purified;

[0048] Salt mud: Remove water and soluble salts from the salt mud by centrifugation or filtration, then dry it to reduce its moisture content, and crush and screen the dried salt mud;

[0049] Oil shale residue: After crushing and screening, degreasing treatment is carried out to remove grease and combustible substances in the oil shale residue to reduce pollution and energy consumption in subsequent processing, and activation treatment is carried out to improve its activity;

[0050] Silicon manganese slag: After crushing and grinding, the particle size distribution that meets the requirements is obtained; magnetic separation and impurity removal: remove metal impurities and other impurities.

[0051] Furthermore, in step S3, the rotation speed of the mill is 500-1500 rpm, the gap between the grinding discs is controlled between 0.2 and 0.5 mm, and the control accuracy is 0.01 mm. After the grinding is completed, a vibration screening machine is used to screen the particle size of the raw material, and the screen is selected with a specification between 1200 and 1800 meshes to ensure that the fineness of the raw material is between 7 and 15 microns.

[0052] The present invention provides an environmentally friendly solid waste-based cementitious material and a preparation method thereof, which has the following beneficial effects:

[0053] The present invention can produce environmentally friendly solid waste-based cementitious materials that meet the requirements of different strength grades. In addition to utilizing traditional common industrial solid waste, it can also effectively utilize other valuable industrial solid wastes such as lithium slag, ammonia-alkali white mud, and salt mud, thereby avoiding the waste of these resources and eliminating the need for other treatment methods to treat them. The solid waste-based cementitious material not only has excellent mechanical properties and environmental friendliness, but also can realize the resource utilization and reduction treatment of industrial solid waste, which is of great significance for promoting green buildings and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of the physical and chemical performance requirements of an environmentally friendly solid waste-based cementitious material of the present invention;

[0055] Figure 2 This is a schematic diagram of the marking composition of an environmentally friendly solid waste-based gelling material of the present invention;

[0056] Figure 3 A schematic diagram of the technical requirements and test methods for lithium slag of an environmentally friendly solid waste-based gelling material of the present invention;

[0057] Figure 4 A schematic flow chart of the steps of a method for preparing an environmentally friendly solid waste-based cementitious material according to the present invention;

[0058] Figure 5 This is a schematic diagram of quality inspection items for a method for preparing an environmentally friendly solid waste-based cementitious material according to the present invention. DETAILED DESCRIPTION

[0059] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0060] like Figure 1-Figure 3 As shown, an environmentally friendly solid waste-based cementitious material includes components: granulated blast furnace slag (should comply with the provisions of GB / T 203), steel slag (should comply with the provisions of YB / T 022), industrial by-product gypsum (should comply with the provisions of GB / T 21371), and other industrial solid wastes. The solid waste-based cementitious materials are divided into 42.5, 32.5 and 22.5 grades according to the strength grade, and the mass percentages of the components of the solid waste-based cementitious materials of different grades are as follows:

[0061] For grades 42.5 and 32.5, 40 parts of granulated blast furnace slag, 30 parts of steel slag, 20 parts of industrial by-product gypsum, and 10 parts of other industrial solid waste;

[0062] For level 22.5, 20 parts of granulated blast furnace slag, 40 parts of steel slag, 20 parts of industrial by-product gypsum, and 20 parts of other industrial solid waste;

[0063] In this embodiment, the particle size of the granulated blast furnace slag ranges from 0.1 to 0.5 mm;

[0064] In this embodiment, other industrial solid wastes include lithium slag, ammonia-alkali white mud, salt mud, oil shale slag, and silicon-manganese slag, and the mass ratio of lithium slag, ammonia-alkali white mud, salt mud, oil shale slag, and silicon-manganese slag is 8:5:3:2:2. The generation pathways of each other industrial solid waste are as follows:

[0065] Lithium slag: solid waste generated during the extraction of lithium and its compounds from lithium-containing ores such as spodumene and lepidolite. The heavy metal leaching concentration limit of lithium slag shall comply with the provisions of GB / T 30760, the radioactivity index shall comply with the provisions of GB6566, and other technical requirements and test methods shall comply with the provisions of GB / T 30760. Figure 3 Requirements: When preparing solid waste-based cementitious materials, lithium slag is used as an auxiliary cementitious material, and its active components can undergo secondary hydration reaction with cement hydration product Ca(OH)2 to generate a large amount of CSH gel, thereby improving the mechanical strength of cement.

[0066] Ammonia-soda mud: The waste residue generated in the mother liquor distillation process, the distillation supernatant recycling process and the equipment cleaning process of Solvay's soda ash production process is a solid waste mainly composed of calcium carbonate, magnesium hydroxide and calcium sulfate. The pH value of ammonia-soda mud is 9-12. The pH value detection method is carried out in accordance with HJ962. At the same time, it should comply with the provisions of my country's environmental protection and safety standards and specifications. The heavy metal leaching concentration limit should comply with the provisions of GB / T 30760, and the radioactivity index should comply with the provisions of GB 6566. When preparing solid waste-based cementitious materials, ammonia-soda mud is used as a calcium raw material, reacting with siliceous and aluminum raw materials (such as granulated blast furnace slag) to form hydration products such as hydrated calcium silicate, thereby contributing to the strength development of the material.

[0067] Salt mud: solid waste discharged during the refining of brine in the process of producing soda ash using salt as the main raw material. Its main components are calcium sulfate, magnesium hydroxide and calcium carbonate. Salt mud should comply with my country's environmental protection and safety standards and specifications. Its heavy metal leaching concentration limit should comply with the provisions of GB / T 30760, and its radioactivity index should comply with the provisions of GB 6566. When preparing solid waste-based cementitious materials, salt mud is used as a filler or regulator, but its addition amount must strictly follow the formula ratio to avoid adverse effects on the performance of the material.

[0068] Oil shale slag: solid waste with silicon dioxide as the main component discharged from oil shale after refining or medium-high temperature heating, and oil shale slag should comply with the provisions of GB / T 2847; when preparing solid waste-based cementitious materials, oil shale slag is used as a siliceous and aluminous raw material, and reacts with calcium raw materials (such as steel slag) to form hydration products such as hydrated calcium silicate.

[0069] Silicon manganese slag: solid waste mainly in a glassy state after water quenching and granulation of silicon manganese-iron alloy molten slag, and the silicon manganese slag should comply with the provisions of YB / T 4229; in the preparation of solid waste-based cementitious materials, silicon manganese slag is used as a siliceous raw material and reacts with calcium and aluminum raw materials to form hydration products such as hydrated calcium silicate.

[0070] In this embodiment, the physical and chemical performance requirements of solid waste-based cementitious materials include fineness, water content, setting time, sulfur trioxide, chloride ions, stability, flexural strength, and compressive strength. The physical and chemical performance requirements of solid waste-based cementitious materials of different grades are different. Figure 1 As shown;

[0071] 1) The physical and chemical performance requirements of different grades of solid waste-based cementitious materials include the following similarities:

[0072] Fineness: 45μm square hole sieve residue ≤12.0%;

[0073] Water content: ≤1.0%;

[0074] Chloride ion: mass fraction ≤ 0.1 a %;

[0075] Stability: qualified by boiling method, ≤0.50% by pressure steaming method, qualified by immersion method;

[0076] 2) The physical and chemical performance requirements of different grades of solid waste-based cementitious materials include the following differences:

[0077] Setting time: initial setting time: 42.5 level, 32.5 level ≥ 45min; 22.5 level ≥ 150min;

[0078] Final setting time: 42.5 level, 32.5 level ≤ 600min; 22.5 level ≤ 1440min;

[0079] Sulfur trioxide: the mass fraction of 42.5 and 32.5 grades is ≤12.0%, the mass fraction of 22.5 grade is ≤16.0%;

[0080] Flexural strength: for grade 42.5, 3d ≥ 3.0MPa, 7d none, 28d ≥ 7.5MPa;

[0081] For level 32.5, 3d≥2.0MPa, 7dNone, 28d≥5.5MPa;

[0082] For level 22.5, 3d none, 7d ≥ 2.0MPa, 28d ≥ 3.5MPa;

[0083] Compressive strength: for grade 42.5, 3d ≥ 15.0MPa, 7d none, 28d ≥ 42.5MPa;

[0084] For level 32.5, 3d≥10.0MPa, 7dNone, 28d≥32.5MPa;

[0085] For level 22.5, 3d no, 7d ≥ 7.0MPa, 28d ≥ 22.5MPa;

[0086] In this embodiment, the mark of the solid waste-based cementitious material consists of three parts: name code, classification code and this document number, wherein the format of the this document number is T / CECS XXXX-20XX, the name code is GC; the classification code follows the strength grade of the solid waste-based cementitious material, specifically: 42.5 grade is marked as 42.5, 32.5 grade is marked as 32.5, and 22.5 grade is marked as 22.5; in this embodiment, taking the 42.5 grade solid waste-based cementitious material as an example, its mark is: GC42.5 T / CECS XXXX-20XX;

[0087] like Figure 4-Figure 5 As shown, a method for preparing an environmentally friendly solid waste-based cementitious material, which is applied to the environmentally friendly solid waste-based cementitious material as described above, comprises the following steps:

[0088] S1. Raw material preparation: Granulated blast furnace slag, steel slag, industrial by-product gypsum and other industrial solid wastes are pre-treated to remove impurities, adjust particle size distribution and improve the uniformity and activity of raw materials; the pre-treatment process of each raw material is as follows:

[0089] 1) Granulated blast furnace slag: The slag is crushed into a particle size of 0.1-0.5 mm by mechanical crushing, and the coarse and fine particles are removed by screening to meet the particle size requirements of the granulated slag. Then, the iron impurities are removed by magnetic separation, and the slag is activated by high-fine grinding or adding activators to improve its activity so that it can better participate in the formation of cementitious materials;

[0090] 2) Steel slag: After crushing, the metal iron and other impurities in the steel slag are removed by magnetic separation and air separation, and then the steel slag is aged to stabilize its performance and reduce fluctuations in subsequent processing;

[0091] 3) Industrial by-product gypsum: first remove impurities such as soil and stones from the gypsum, then crush and grind the gypsum to the required fineness, and adjust the moisture content of the gypsum as needed to ensure its compatibility with other raw materials;

[0092] 4) Other industrial solid waste:

[0093] Lithium slag: After crushing and screening, the particle size distribution that meets the requirements is obtained, and the lithium slag is chemically treated to remove harmful substances or improve its activity;

[0094] Ammonia-soda white mud: After dehydration treatment, excess water is removed, and the white mud is crushed and ground to the required fineness, and then impurities and pollutants in the white mud are removed and purified;

[0095] Salt mud: Remove water and soluble salts from the salt mud by centrifugation or filtration, then dry it to reduce its moisture content, and crush and screen the dried salt mud;

[0096] Oil shale residue: After crushing and screening, degreasing treatment is carried out to remove grease and combustible substances in the oil shale residue to reduce pollution and energy consumption in subsequent processing, and activation treatment is carried out to improve its activity;

[0097] Silicon manganese slag: After crushing and grinding, the particle size distribution that meets the requirements is obtained; magnetic separation and impurity removal: remove metal impurities and other impurities;

[0098] S2. Batching and mixing: According to the formula requirements, the pretreated raw materials are batched in proportion and mixed evenly;

[0099] S3, grinding: the mixed raw materials are sent to the mill for grinding, the speed of the mill is 500-1500rpm, the gap between the grinding discs is controlled between 0.2-0.5 mm, and the control accuracy is 0.01 mm. After the grinding, the particle size of the raw materials is screened by a vibration screening machine, and the screen mesh is selected between 1200-1800 meshes to obtain a raw material semi-finished product with a fineness between 7-15 microns, so as to ensure its hydration reaction speed and strength development;

[0100] S4. Homogenization: The ground material is homogenized to make the particle size distribution of the material more uniform, so as to eliminate the influence of the particle size difference caused by the grinding process on the material performance;

[0101] S5. Finished product inspection and packaging: The finished product will be inspected for quality, including fineness, setting time, stability and other indicators. After passing the inspection, the finished product will be packaged and marked for transportation and use.

[0102] In this embodiment, the products are numbered and sampled according to the same strength grade before leaving the factory. Bulk and bagged solid waste-based cementitious materials should be numbered and sampled separately. Each number is a sampling unit. The factory number is stipulated according to the annual production capacity of the solid waste-based cementitious material manufacturer as follows:

[0103] a) Annual production capacity> 60x104t, but not exceeding 500t;

[0104] b) Annual production capacity>30x10t, not exceeding 200t;

[0105] c) Annual production capacity>10x10t, not exceeding 100t;

[0106] d) Annual production capacity ≤ 10x10t, not exceeding 50t.

[0107] When the capacity of the bulk transport vehicle exceeds the tonnage of the factory number specified by the factory, the tonnage of the number is allowed to exceed the tonnage specified for sampling.

[0108] The sampling method is as follows: random sampling is carried out according to GB / T 12573. The sampling should be representative. The sampling can be continuous or equal samples can be taken from more than 20 different parts. The total weight of each sample is at least 20kg. After the sample is mixed evenly, it is divided into quarters to take out a sample that is twice the amount required for the test.

[0109] Quality inspection items are Figure 4 The inspections specified in the Regulations include factory inspection and type inspection, of which factory inspection is mandatory. However, type inspection shall be conducted if any of the following situations occurs:

[0110] a) When the source, type and process of raw materials change, which may affect the performance of the product;

[0111] b) When a new product is being trial-produced or a product is being resumed after being discontinued for more than 6 months;

[0112] c) When there is a significant difference between the factory inspection result and the last type inspection result;

[0113] d) During normal production, inspection shall be conducted once a year.

[0114] In this embodiment, the inspection method of each indicator is as follows:

[0115] Fineness (residue on 45μm square hole sieve): Test in accordance with GB / T 1345.

[0116] Moisture content: Test according to the provisions in Appendix B.

[0117] Setting time: Test according to the requirements of GB / T 1346.

[0118] Sulfur trioxide: test in accordance with the provisions of GB / T 176.

[0119] Chloride ion: Test according to the requirements of GB / T 176.

[0120] Stability:

[0121] Ⅰ. The boiling method is carried out in accordance with the provisions of GB / T 1346, where the boiling start time is 48h±2h of specimen curing. If the test is affected by coagulation and hardening, the boiling time can be appropriately extended.

[0122] Ⅱ. The pressure steaming method is tested in accordance with the provisions of GB / T 750, where the demoulding time is 48h±2h for the specimen to be cured. If demoulding is impossible, the time may be appropriately extended.

[0123] III. The immersion method shall be tested in accordance with the provisions of JC / T 1099, where the starting time of immersion is 48h±2h of specimen curing. If the test is affected by coagulation and hardening, the immersion time may be appropriately extended.

[0124] Radioactivity: Test according to the requirements of GB 6566.

[0125] Leachable heavy metal content: Test according to the provisions of GB / T 30810.

[0126] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. An environmentally friendly solid waste-based cementitious material, comprising components: granulated blast furnace slag, steel slag, industrial by-product gypsum, and other industrial solid wastes, characterized in that: The solid waste-based cementitious materials are divided into 42.5, 32.5 and 22.5 grades according to their strength grades, and the weight percentages of the components of the solid waste-based cementitious materials of different grades are as follows: For grades 42.5 and 32.5, 30-60 parts of granulated blast furnace slag, 20-50 parts of steel slag, 20-25 parts of industrial by-product gypsum, and 10-20 parts of other industrial solid waste; For level 22.5, 20-30 parts of granulated blast furnace slag, 30-60 parts of steel slag, 20-30 parts of industrial by-product gypsum, and 20-30 parts of other industrial solid waste.

2. The environmentally friendly solid waste-based cementitious material according to claim 1, characterized in that: The particle size of the granulated blast furnace slag is in the range of 0.1 to 0.5 mm.

3. The environmentally friendly solid waste-based cementitious material according to claim 1, characterized in that: The other industrial solid wastes include lithium slag, ammonia-alkali white mud, salt mud, oil shale slag, and silicon-manganese slag, and the mass ratio of lithium slag, ammonia-alkali white mud, salt mud, oil shale slag, and silicon-manganese slag is 8:5:3:2:

2. The generation pathways of the other industrial solid wastes are as follows: Lithium slag: solid waste generated during the extraction of lithium and its compounds from lithium-containing ores such as spodumene and lepidolite; Ammonia-soda mud: waste residue generated during the mother liquor distillation process, the distillation supernatant recycling process and the equipment cleaning process of Solvay's soda ash production process. It is a solid waste mainly composed of calcium carbonate, magnesium hydroxide and calcium sulfate. Salt mud: solid waste discharged during the refining of brine in the process of producing soda ash using salt as the main raw material. Its main components are calcium sulfate, magnesium hydroxide and calcium carbonate. Oil shale residue: solid waste with silicon dioxide as the main component discharged from oil shale after refining or medium-high temperature heating; Silicon-manganese slag: solid waste mainly in glassy state after quenching and granulation of molten silico-manganese-ferroalloy slag.

4. The environmentally friendly solid waste-based cementitious material according to claim 1, characterized in that: The physical and chemical property requirements of the solid waste-based cementitious materials include fineness, water content, setting time, sulfur trioxide, chloride ions, stability, flexural strength, and compressive strength, and there are differences in the physical and chemical property requirements of different grades of solid waste-based cementitious materials.

5. The environmentally friendly solid waste-based cementitious material according to claim 4, characterized in that: The physical and chemical performance requirements of different grades of solid waste-based cementitious materials include the following similarities: Fineness: 45μm square hole sieve residue ≤12.0%; Water content: ≤1.0%; Chloride ion: mass fraction ≤ 0.1 a %; Stability: qualified by boiling method, ≤0.50% by pressure steaming method, qualified by immersion method.

6. The environmentally friendly solid waste-based cementitious material according to claim 4, characterized in that: The physical and chemical performance requirements of different grades of solid waste-based cementitious materials include the following differences: Setting time: initial setting time: 42.5 level, 32.5 level ≥ 45min; 22.5 level ≥ 150min; Final setting time: 42.5 level, 32.5 level ≤ 600min; 22.5 level ≤ 1440min; Sulfur trioxide: the mass fraction of 42.5 and 32.5 grades is ≤12.0%, the mass fraction of 22.5 grade is ≤16.0%; Flexural strength: for grade 42.5, 3d ≥ 3.0MPa, 7d none, 28d ≥ 7.5MPa; For level 32.5, 3d≥2.0MPa, 7dNone, 28d≥5.5MPa; For level 22.5, 3d none, 7d ≥ 2.0MPa, 28d ≥ 3.5MPa; Compressive strength: for grade 42.5, 3d ≥ 15.0MPa, 7d none, 28d ≥ 42.5MPa; For level 32.5, 3d≥10.0MPa, 7dNone, 28d≥32.5MPa; For level 22.5, 3d: none, 7d≥7.0MPa, 28d≥22.5MPa.

7. The environmentally friendly solid waste-based cementitious material according to claim 1, characterized in that: The marking of the solid waste-based cementitious material consists of three parts: the name code, the classification code and the document number. The format of the document number is T / CECS XXXX-20XX, and the name code is GC; the classification code complies with the strength grade of the solid waste-based cementitious material, specifically: 42.5 grade is marked as 42.5, 32.5 grade is marked as 32.5, and 22.5 grade is marked as 22.

5.

8. A method for preparing an environmentally friendly solid waste-based cementitious material, applied to an environmentally friendly solid waste-based cementitious material as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Raw material preparation: Pre-treat granulated blast furnace slag, steel slag, industrial by-product gypsum and other industrial solid wastes to remove impurities, adjust particle size distribution and improve the uniformity and activity of raw materials; S2. Batching and mixing: According to the formula requirements, the pretreated raw materials are batched in proportion and mixed evenly; S3, grinding: the mixed raw materials are sent to the mill for grinding to obtain the required fineness to ensure its hydration reaction speed and strength development; S4. Homogenization: The ground material is homogenized to make the particle size distribution of the material more uniform, so as to eliminate the influence of the particle size difference caused by the grinding process on the material performance; S5. Finished product inspection and packaging: Carry out quality inspection on the finished products. After passing the inspection, the finished products will be packaged and marked.

9. The method for preparing an environmentally friendly solid waste-based cementitious material according to claim 8, characterized in that: In step S1, the pretreatment process of each raw material is as follows: 1) Granulated blast furnace slag: The slag is crushed into a particle size of 0.1-0.5 mm by mechanical crushing, and the coarse and fine particles are removed by screening. Then, the iron impurities are removed by magnetic separation, and the slag is activated by high-fine grinding or adding an activator. 2) Steel slag: After crushing, the metal iron and other impurities in the steel slag are removed by magnetic separation and air separation, and then the steel slag is aged; 3) Industrial by-product gypsum: first remove impurities in the gypsum, then crush and grind the gypsum to the required fineness, and adjust the moisture content of the gypsum as needed; 4) Other industrial solid waste: Lithium slag: After crushing and screening, the particle size distribution that meets the requirements is obtained, and the lithium slag is chemically treated to remove harmful substances or improve its activity; Ammonia-soda white mud: After dehydration treatment, excess water is removed, and the white mud is crushed and ground to the required fineness, and then impurities and pollutants in the white mud are removed and purified; Salt mud: remove water and soluble salts from the salt mud by centrifugation or filtration, then dry it, and crush and screen the dried salt mud; Oil shale residue: After crushing and screening, degreasing treatment is carried out to remove grease and combustible substances in the oil shale residue, and activation treatment is carried out; Silicon manganese slag: After crushing and grinding, the particle size distribution that meets the requirements is obtained; magnetic separation and impurity removal: remove metal impurities and other impurities.

10. The method for preparing an environmentally friendly solid waste-based cementitious material according to claim 8, characterized in that: In step S3, the rotation speed of the mill is 500-1500 rpm, the gap between the grinding discs is controlled between 0.2 and 0.5 mm, and the control accuracy is 0.01 mm. After the grinding is completed, a vibration screening machine is used to screen the particle size of the raw material to ensure that the fineness of the raw material is between 7 and 15 microns.

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