A low-cost clinker-free cementitious material and its application

Abstract

The present invention discloses a low-cost clinker-free cementitious material and its application, which belongs to the field of building materials. Taking the mass of the clinker-free cementitious material as 100%, it includes the following raw materials in percentage by mass: 20-60% of water-quenched blast furnace slag, 10-40% of garbage incineration bottom ash, 20% of washed garbage incineration fly ash, and the balance is desulfurization gypsum. The low-cost clinker-free cementitious material is used to replace cement solidification stabilization on a large scale in preliminary combination with cementitious filling mining technology, or to provide a low-cost cement-free clinker cementitious material for preparing concrete for the construction industry. The low-cost clinker-free cementitious material provided by the present invention has a simple composition and a high overall economic benefit, improves the recycling rate of washed garbage incineration fly ash and garbage incineration bottom ash, and synergistically recycles washed garbage incineration fly ash and garbage incineration bottom ash that are more difficult to comprehensively utilize.

Description

Technical Field

[0001] The invention belongs to the field of building materials and relates to a low-cost clinker-free gelling material and an application thereof. Background Art

[0002] Global municipal solid waste production is projected to reach 2.2 billion tons by 2025. Incineration-to-energy technology can reduce waste volume and weight by 90% and 70%, respectively, making it a key approach to municipal solid waste management. Statistics show that China incinerates over 100 million tons of municipal solid waste annually. The incineration process produces two primary particulate byproducts: fly ash and bottom ash, which account for 25-30% and 3-5% of the total waste incinerated, respectively. According to the National List of Hazardous Wastes, fly ash (hereinafter referred to as fly ash) is classified as hazardous waste. Unlike fly ash, bottom ash, collected from the bottom of the furnace, is the largest source, accounting for approximately 80-90% of the solid residue. It is typically physically sorted to remove large pieces of glass or iron-containing materials. Its chloride content and pollutant concentrations are low, making it a general solid waste. At present, under the background of rapid incineration of municipal solid waste and huge annual production of fly ash, the coordinated harmless disposal of waste incineration fly ash and waste incineration bottom ash and the potential safety hazards caused to the environment and human health have become hot topics in the research field of solid waste and hazardous waste treatment.

[0003] Clinker in building materials typically refers to Portland cement clinker, also known internationally as Portland cement clinker. It is a hydraulic cementitious material composed primarily of calcium silicate, obtained by grinding raw materials containing CaO, SiO₂, Al₂O₃, and Fe₂O₃ into a fine powder in appropriate proportions and calcining them into a partially molten state. As an essential step in cement production, the production process is highly complex, consisting of five steps: crushing and pre-homogenization, raw material preparation, raw material homogenization, pre-thermal decomposition, and clinker calcination. Crushing and pre-homogenization further involves crushing and pre-homogenization of the raw materials. This entire process is complex, costly, energy-intensive, and has high carbon emissions. Therefore, developing green cementitious materials to replace cement clinker has become a new research direction.

[0004] Water washing (also known as neutral leaching) is a type of fly ash pretreatment that can effectively remove Cl - Soluble salts and some heavy metals. Currently, there is a lot of research on the use of washed fly ash in conjunction with other solid wastes or cement to produce green cementitious materials, which provides strong theoretical support for engineering implementation. However, these studies have not yet considered the synergistic treatment of washed fly ash and bottom ash to produce low-cost cement-free clinker cementitious materials.

[0005] At present, my country's incineration treatment technologies are mainly divided into three categories: grate furnace technology, fluidized bed technology and other incineration technologies. Waste incineration fly ash is fine particles carried by the air flow and collected in air pollution control devices. According to the different incineration technologies, it is mainly divided into grate furnace fly ash and circulating fluidized bed fly ash. The grate furnace process incinerator completely burns through the mechanical movement of the grate, producing less fly ash, accounting for 2.5% of the total amount of garbage, but its chloride content (about 20%) and heavy metal content are high. In fluidized bed incinerators, garbage is usually burned with the help of coal and quartz sand, and the fly ash production is higher, accounting for 8-12% of the total amount of garbage. It has the characteristics of high silicon and aluminum content and low soluble salt content (about 5%). Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the existing technology of cementitious materials containing water-washed waste incineration fly ash has the following problems: too many activators, early strength agents and other admixtures need to be added to have practical strength, or complete replacement of cement is not achieved, and the potential utilization value of bottom ash, a high-silicate material also produced by the waste incineration process, in preparing cementitious materials by synergizing industrial solid waste solidified fly ash is ignored.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] A low-cost clinker-free cementitious material comprises the following raw materials in percentage by mass: 20-60% of water-quenched blast furnace slag, 10-40% of waste incineration bottom ash, 20% of water-washed waste incineration fly ash, and the balance being desulfurized gypsum, based on the mass of the clinker-free cementitious material being 100%.

[0009] Preferably, the water-quenched blast furnace slag refers to any water-quenched blast furnace slag having a 28d activity index of not less than 95%.

[0010] Preferably, the waste incineration bottom ash refers to the bottom ash generated during the incineration and disposal of domestic waste or industrial waste, and its main components are quartz, calcium carbonate and calcium magnesium feldspar, with a high content of active components, which can fully stimulate the activity of water-quenched blast furnace slag.

[0011] Preferably, the washed waste incineration fly ash refers to fly ash generated during the incineration and disposal of domestic waste or industrial waste, which is then pretreated under different water washing conditions, and is not limited to the source or type of waste.

[0012] Preferably, the main component of the desulfurized gypsum is similar to natural gypsum, namely calcium sulfate dihydrate.

[0013] The chemical composition of the washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag and desulfurization gypsum described in the present invention refers to the content of various metal or mineral elements in the form of oxides, and does not refer to the content of their compounds existing in the form of oxides in the washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag or desulfurization gypsum.

[0014] Preferably, in terms of mass percentage, the CaO content in the washed waste incineration fly ash is ≥45%, the Cl content is ≥20%, the Na2O content is ≥10%, the SiO2 content is ≥3%, and the Al2O3 content is ≥2%.

[0015] Preferably, in terms of mass percentage, the SiO2 content in the waste incineration bottom ash is ≥32%, the CaO content is ≥30%, the Al2O3 content is ≥7%, the Fe2O3 content is ≥5%, and the Na2O content is ≥2%.

[0016] Preferably, in terms of mass percentage, the CaO content in the water-quenched blast furnace slag is ≥35%, the SiO2 content is ≥28%, the Al2O3 content is ≥12%, and the MgO content is ≥5%.

[0017] Preferably, in terms of mass percentage, the content of CaO in the desulfurization gypsum is ≥45%, and the content of SO3 is ≥40%.

[0018] Preferably, the specific surface area of ​​the water-quenched blast furnace slag is 450 to 500 m 2 / kg, the specific surface area of ​​the washed waste incineration fly ash is 550-600m 2 / kg, the specific surface area of ​​the waste incineration bottom ash is 400-450m 2 / kg, the specific surface area of ​​the desulfurized gypsum is 450-500m 2 / kg. Grinding increases the specific surface area of ​​the raw materials, which, on the one hand, stimulates the activity of the water-quenched blast furnace slag and reduces the difficulty of hydration, and on the other hand, improves the uniformity of the material.

[0019] The invention discloses an application of a low-cost clinker-free cementitious material, wherein the low-cost clinker-free cementitious material is applied to replace cement solidification stabilization on a large scale in preliminary combined cement filling mining technology, or to provide a low-cost cement-free clinker cementitious material for preparing concrete for the construction industry.

[0020] The low-cost clinker-free cementitious material is used in the preparation of low-cost cement-free clinker, comprising the following steps:

[0021] Water and the low-cost clinker-free cementitious material are mixed in a mass ratio of 3:10, and a filling material sample is prepared according to GB17671-1999 "Test Method for Strength of Cement Mortar", and the filling material is used to replace cement and other building materials after curing.

[0022] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0023] In the above scheme, compared with the existing low-cost cementitious materials containing water-washed waste incineration fly ash and water-quenched blast furnace slag, the cementitious material of the present invention synergistically utilizes the waste incineration bottom ash as a resource, has a simpler composition, does not require the addition of admixtures such as activators and early strength agents, and does not require the addition of cement clinker. It is composed of four components: water-quenched blast furnace slag, water-washed waste incineration fly ash, waste incineration bottom ash and desulfurization gypsum, which greatly reduces the cost of raw materials and has a higher utilization rate of water-washed waste incineration fly ash and waste incineration bottom ash.

[0024] The use of water-quenched blast furnace slag and desulfurized gypsum to coordinately utilize washed garbage incineration fly ash and garbage incineration bottom ash to prepare low-cost cement-free clinker cementitious materials can not only solve the problems of reduction, harmlessness and resource utilization of industrial solid waste (water-quenched blast furnace slag, desulfurized gypsum), urban hazardous waste (washed garbage incineration fly ash) and urban solid waste (garbage incineration bottom ash), but also promote the coordinated resource utilization of solid and hazardous waste and environmental protection, and lay the foundation for engineering application of large-scale replacement of cement-solidified stabilized fly ash for safe landfill, or provide low-cost cement-free clinker cementitious materials for the concrete construction industry or mining filling field.

[0025] In summary, the low-cost clinker-free cementitious material provided by the present invention has a simple composition and high overall economic benefits, improves the recycling rate of water-washed waste incineration fly ash and waste incineration bottom ash, simplifies the raw material composition of the cementitious material containing water-washed waste incineration fly ash and waste incineration bottom ash water-quenched blast furnace slag, and synergistically recycles and utilizes water-washed waste incineration fly ash and waste incineration bottom ash that are more difficult to comprehensively utilize. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A process flow chart of a low-cost method for preparing clinker-free cementitious materials and an application process according to an embodiment of the present invention;

[0028] Figure 2 This is a process flow chart of a test on water washing pretreatment conditions for waste incineration fly ash according to an embodiment of the present invention;

[0029] Figure 3 This is a graph showing the particle size distribution change of the gelling raw material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will describe the technical solutions and technical problems solved in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them.

[0031] The fly ash used in the embodiments of the present invention is obtained from the grate furnace incineration process of the State Power Investment Corporation Guiyang China Power Environmental Protection Power Plant. The garbage is dried, incinerated, and burned in different combustion sections of the grate. The fine combustion particles collected in the heat recovery system (heat recovery boiler) and the flue gas purification system (dust collector) contain much higher levels of heavy metals, dioxins, and chloride salts than fly ash produced by other incineration technologies. The garbage incineration fly ash is then pretreated under different water washing conditions through the grate furnace process to obtain water-washed garbage incineration fly ash for preparing cement-free clinker cementitious materials with optimal performance (compressive strength).

[0032] The waste incineration bottom ash used in the embodiment of the present invention is taken from the incombustible mixture (slag) deposited at the bottom of the combustion boiler in the grate furnace technology of the Guiyang Zhongdian Environmental Protection Power Plant of the State Power Investment Corporation. It is collected from the bottom of the furnace and the output accounts for about 80-90% of the solid residue. After physical separation of large pieces of glass or iron-containing substances, its chloride content and pollutant concentration are low, and it is classified as general solid waste.

[0033] The cementitious material of the present invention is usually mixed with water and cementitious material at a mass ratio of (1-2):5 when used. This water-cement ratio can be used to replace cement on a large scale for solidification and stabilization, and to initially combine cemented filling mining technology or prepare concrete for the construction industry to provide low-cost cement-free clinker cementitious material. The specific process implementation flow chart of the embodiment of the present invention is shown in FIG. Figure 1 shown.

[0034] Furthermore, before preparing the gelling material required in this embodiment, it is necessary to first conduct a water washing pretreatment condition test on the waste incineration fly ash. The test method is as follows:

[0035] Take 20g of dried fly ash raw material and put it into a 1L polyvinyl chloride container. Set the two variables of L / S and oscillation time. Slowly add deionized water according to the water-ash ratio / liquid-solid ratio (L / S) of 3. Then oscillate at room temperature at a frequency of 110±10 times / min in two time gradients for 1 and 5 minutes respectively, as shown in Table 1. Then remove the container and vacuum filter all the washing solutions through a 0.45μm filter membrane. The remaining washed fly ash residue and the filter membrane are placed in an oven at a temperature of 50℃ for 2 days. Then the filter residue is dried and homogenized to obtain the washed fly ash. The specific washing operation process is as follows: Figure 2 shown.

[0036] Table 1 shows the fly ash parallel samples W1 and W7 under different water washing test conditions.

[0037] Table 1 Fly ash parallel samples under different water washing test conditions

[0038] Types of washed fly ash W1 W7 Liquid-to-solid ratio (L / S) 3 3 Washing time (minutes) 1 5

[0039] Furthermore, the particle size distribution of waste incineration fly ash and desulfurization gypsum is as follows: Figure 3 shown.

[0040] Depend on Figure 3 It can be seen that the proportions of waste incineration fly ash in the particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm are 4.72%, 31.26%, 20.64%, 21.90%, 21.38% and 0% respectively;

[0041] The proportions of waste incineration bottom ash in the particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm are 4.25%, 21.21%, 11.29%, 12.22%, 20.89% and 30.14% respectively;

[0042] Water-quenched blast furnace slag was obtained from Liupanshui Shuigang Group, with particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm accounting for 21.59%, 49.50%, 13.86%, 5.90%, 4.78%, and 4.37%, respectively;

[0043] Desulfurization gypsum was taken from the pulverized coal furnace of Puding County Power Plant, with particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm accounting for 5.69%, 40.86%, 12.59%, 12.70%, 17.88% and 10.28% respectively.

[0044] Furthermore, the waste incineration bottom ash used in the embodiments and comparative examples of the present invention needs to be ground to a specific gravity of 450m 2 / kg, water-quenched blast furnace slag needs to be ground to a specific gravity of 500m 2 / kg, desulfurized gypsum needs to be ground to a specific gravity of 450m 2 / kg.

[0045] Example 1

[0046] A low-cost clinker-free cementitious material, consisting of the following components by mass percentage:

[0047] Washed waste incineration fly ash 20%, waste incineration bottom ash 16%, water-quenched blast furnace slag 48%, desulfurization gypsum 14%.

[0048] In this embodiment, washed fly ash (W1) with a Cl content of about 6 is selected. Among them, the washed fly ash (W1) in the particle size range of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm accounts for 2.89%, 8.16%, 10.33%, 21.23%, 30.85% and 26.55% respectively; the water-quenched blast furnace slag in the particle size range of 0.1-1, 1-10, 10-25, 25-50, 50-110, 110-500 μm accounts for 2.89%, 8.16%, 10.33%, 21.23%, 30.85% and 26.55% respectively. The particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm accounted for 21.59%, 49.50%, 13.86%, 5.90%, 4.78%, and 4.37%, respectively. Desulfurized gypsum accounted for 5.69%, 40.86%, 12.59%, 12.70%, 17.88%, and 10.28%, respectively. Washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum were weighed in the stated proportions and filler samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0049] Example 2

[0050] A low-cost clinker-free cementitious material, consisting of the following components by mass percentage:

[0051] Washed waste incineration fly ash 20%, waste incineration bottom ash 22%, water-quenched blast furnace slag 44%, desulfurization gypsum 14%.

[0052] In this example, washed fly ash (W1) with a Cl content of approximately 6 was selected. The particle size distribution of washed fly ash (W1), water-quenched blast furnace slag, and desulfurized gypsum was the same as in Example 1. Washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum were weighed in the stated proportions, and filler material samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0053] Example 3

[0054] A low-cost clinker-free cementitious material, consisting of the following components by mass percentage:

[0055] Washed waste incineration fly ash 20%, waste incineration bottom ash 30%, water-quenched blast furnace slag 30%, desulfurization gypsum 20%.

[0056] In this example, washed fly ash (W1) with a Cl content of approximately 6 was selected. The particle size distribution of washed fly ash (W1), water-quenched blast furnace slag, and desulfurized gypsum was the same as in Example 1. Washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum were weighed in the stated proportions, and filler material samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0057] Example 4

[0058] A low-cost clinker-free cementitious material, consisting of the following components by mass percentage:

[0059] Washed waste incineration fly ash 20%, waste incineration bottom ash 15%, water-quenched blast furnace slag 45%, desulfurization gypsum 20%.

[0060] In this example, washed fly ash (W7) with a Cl content of approximately 1 was selected. The particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm for the washed fly ash (W7) were 3.21%, 9.48%, 11.33%, 22.97%, 33.72%, and 19.29%, respectively. The particle size distributions of water-quenched blast furnace slag and desulfurized gypsum were the same as in Example 1. Washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum were weighed according to the stated proportions, and filler samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0061] Example 5

[0062] A low-cost clinker-free cementitious material, consisting of the following components by mass percentage:

[0063] Washed waste incineration fly ash 20%, waste incineration bottom ash 22%, water-quenched blast furnace slag 44%, desulfurization gypsum 14%.

[0064] In this example, washed fly ash (W7) with a Cl content of approximately 1 was selected. The particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm for the washed fly ash (W7) were 3.21%, 9.48%, 11.33%, 22.97%, 33.72%, and 19.29%, respectively. The particle size distributions of water-quenched blast furnace slag and desulfurized gypsum were the same as in Example 1. Washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum were weighed according to the stated proportions, and filler samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0065] Example 6

[0066] A low-cost clinker-free cementitious material, consisting of the following components by mass percentage:

[0067] Washed waste incineration fly ash 20%, waste incineration bottom ash 34%, water-quenched blast furnace slag 34%, desulfurization gypsum 12%.

[0068] In this example, washed fly ash (W7) with a Cl content of approximately 1 was selected. The particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm for the washed fly ash (W7) were 3.21%, 9.48%, 11.33%, 22.97%, 33.72%, and 19.29%, respectively. The particle size distributions of water-quenched blast furnace slag and desulfurized gypsum were the same as in Example 1. Washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum were weighed according to the stated proportions, and filler samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0069] Before preparing the cementitious material required for the comparative example, it is not necessary to perform water washing pretreatment on the waste incineration fly ash.

[0070] Comparative Example 1

[0071] A low-cost clinker-free cementitious material, consisting of the following components by mass percentage:

[0072] Waste incineration fly ash 20%, waste incineration bottom ash 17%, water-quenched blast furnace slag 51%, and desulfurization gypsum 12%.

[0073] In this example, washed fly ash (W7) with a Cl content of approximately 1 was selected. The particle size ranges of 0.1-1, 1-10, 10-25, 25-50, 50-110, and 110-500 μm for the washed fly ash (W7) were 3.21%, 9.48%, 11.33%, 22.97%, 33.72%, and 19.29%, respectively. The particle size distributions of water-quenched blast furnace slag and desulfurized gypsum were the same as in Example 1. Washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum were weighed according to the stated proportions, and filler samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0074] Comparative Example 2

[0075] A cement clinker-containing gelling material, comprising the following components by mass percentage:

[0076] Waste incineration fly ash 20%, cement 70%, desulfurization gypsum 10%.

[0077] In this example, washed fly ash (W7) with a Cl content of approximately 1 was selected. The particle size distribution of waste incineration fly ash and desulfurization gypsum was the same as that in Comparative Example 1. Waste incineration fly ash, cement, and desulfurization gypsum were weighed in the stated proportions, and filler samples were prepared according to GB17671-1999, "Test Method for Cement Mortar Strength."

[0078] Water was mixed with the cementitious materials of Examples 1 to 6 and Comparative Examples 1 to 2 at a mass ratio of 3:10, and filling material samples were prepared according to GB17671-1999 "Test Method for Strength of Cement Mortar". The sample size was 30 mm × 30 mm × 50 mm, and the samples were cured at a temperature of 35°C and a humidity of more than 99.5%.

[0079] The compressive strength of molded test blocks with different curing ages was tested according to the Chinese standard GB / T17671-1999 "Test Methods of Cement - Determination of Strength" (MTCDS), and a total cost-benefit analysis was conducted.

[0080] The specific cost-effectiveness calculation process is shown in Table 2:

[0081] Table 2 Example of cost-benefit analysis of low-cost clinker-free cementitious materials

[0082]

[0083]

[0084] The total cost-benefit analysis was conducted assuming the unit price of low-cost clinker-free cementitious materials was RMB 250 per ton. The compressive strength test and total cost-benefit analysis results are shown in Table 3:

[0085] Table 3 Compressive strength of pure slurry cementitious material test blocks

[0086]

[0087] Results: Table 3 shows that while Comparative Example 1 (containing unwashed fly ash) achieved the highest total economic benefit of 332.73 yuan / t, its 28-day compressive strength was 30.66 MPa, lower than the 28-day compressive strengths of Examples 1, 2, 4, and 5 (containing washed waste incineration fly ash W1 and W7) (31.38-37.50 MPa). Furthermore, the total economic benefit of Comparative Example 2 (containing cement) was only 187.96 yuan / t. Low-cost clinker-free cementitious materials exhibited a strong economic advantage, with total economic benefits ranging from 293.69 to 318.29 yuan / t for Examples 1-5.

[0088] As can be seen from Tables 1 and 3 above, the embodiments of the present invention still exhibit relatively high compressive strength after using fly ash with such significant hazards to produce cementitious materials. This indicates that the washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag, and desulfurized gypsum in the embodiments of the present invention exhibit good synergy. This synergy can improve the compressive strength of the cementitious materials and allow for the harmless disposal of the washed waste incineration fly ash and waste incineration bottom ash, resulting in extremely high economic benefits.

[0089] The embodiment of the present invention synergistically utilizes waste incineration bottom ash, simplifies the composition, and can still show good bonding properties due to the synergistic effect, including compressive strength and effective solidification of various heavy metals in fly ash and high compressive strength.

[0090] In summary, this material invention synergistically utilizes washed waste incineration fly ash, waste incineration bottom ash, water-quenched blast furnace slag and desulfurization gypsum to prepare low-cost cement-free clinker cementitious materials, determines the particle size distribution range of the raw materials, maximizes the resource utilization of waste incineration fly ash and waste incineration bottom ash, provides the optimal dosage of washed waste incineration fly ash and waste incineration bottom ash in the cement-free clinker cementitious system, and brings extremely high economic benefits.

[0091] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A low-cost clinker-free cementitious material, characterized in that: Taking the mass of the clinker-free cementitious material as 100%, the material is composed of the following raw materials in percentage by mass: 20-60% of water-quenched blast furnace slag, 10-40% of waste incineration bottom ash, 20% of washed waste incineration fly ash, and the balance being desulfurized gypsum; The waste incineration bottom ash refers to the bottom ash generated during the incineration and disposal of domestic waste or industrial waste, and its main components are quartz, calcium carbonate and calcite; The washed waste incineration fly ash refers to the fly ash generated during the incineration and disposal of domestic waste or industrial waste, which is then pretreated under different water washing conditions and is not limited to the source or type of waste.

2. The low-cost clinker-free cementitious material according to claim 1, characterized in that: Calculated by mass percentage, the CaO content in the washed waste incineration fly ash is ≥45%, the Cl content is ≥20%, the Na2O content is ≥10%, the SiO2 content is ≥3%, and the Al2O3 content is ≥2%.

3. The low-cost clinker-free cementitious material according to claim 1, characterized in that: Calculated by mass percentage, the SiO2 content in the waste incineration bottom ash is ≥32%, the CaO content is ≥30%, the Al2O3 content is ≥7%, the Fe2O3 content is ≥5%, and the Na2O content is ≥2%.

4. The low-cost clinker-free cementitious material according to claim 1, characterized in that: Calculated by mass percentage, the CaO content in the water-quenched blast furnace slag is ≥35%, the SiO2 content is ≥28%, the Al2O3 content is ≥12%, and the MgO content is ≥5%.

5. The low-cost clinker-free cementitious material according to claim 1, characterized in that: Calculated by mass percentage, the content of CaO in the desulfurization gypsum is ≥45%, and the content of SO3 is ≥40%.

6. The low-cost clinker-free cementitious material according to claim 1, characterized in that: The specific surface area of ​​the water-quenched blast furnace slag is 450 to 500 m 2 / kg, the specific surface area of ​​the washed waste incineration fly ash is 550-600m 2 / kg, the specific surface area of ​​the waste incineration bottom ash is 400-450m 2 / kg, the specific surface area of ​​the desulfurized gypsum is 450-500m 2 / kg.

7. Use of the low-cost clinker-free cementitious material according to any one of claims 1 to 6, characterized in that: The low-cost clinker-free cementitious material is used to replace cement solidification stabilization on a large scale in preliminary combined cement filling mining technology, or to provide a low-cost cement-free clinker cementitious material for preparing concrete for the construction industry.

8. The use of the low-cost clinker-free cementitious material according to claim 7, characterized in that: The low-cost clinker-free cementitious material is used in the preparation of low-cost cement-free clinker, comprising the following steps: Water and the low-cost clinker-free cementitious material are mixed in a mass ratio of 3:10, and a filling material sample is prepared according to GB17671-1999 "Test Method for Strength of Cement Mortar", and the filling material is used to replace cement and other building materials after curing.

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