A ready-mix coal-based solid waste fluidified solidified material

Abstract

This invention relates to the field of premixed coal-based solid waste treatment, specifically disclosing a premixed coal-based solid waste fluidized solidification material, comprising aggregates prepared from coal gangue and a solidifying agent. The aggregates are entirely coal-based solid waste aggregates, containing no other aggregate components. The solidifying agent consists of powder prepared by crushing coal gangue to particles smaller than 0.075mm and cement, and accounts for 1-20% of the aggregate weight. The comprehensive utilization scheme developed in this application requires only simple processing such as crushing and screening to achieve low-cost, high-efficiency, and high-value utilization of coal gangue. The prepared fluidized solidification product's performance far exceeds general standard requirements and can be applied to the stabilization and solidification of cavities, pits, trenches, culverts, and soil layers; non-load-bearing filling of the interior and upper spaces of buildings and structures; and backfilling projects with strict construction requirements, such as abutments, culvert backs, and wall backs in transportation engineering, truly realizing high-value reuse of solid waste.

Description

Technical Field

[0001] This application relates to the field of premixed coal-based solid waste treatment, specifically to a premixed coal-based solid waste fluidized solidification material, and particularly to a fluidized solidification material based on coal gangue, the product prepared therefrom, and the corresponding preparation and construction methods. Background Technology

[0002] Coal gangue is a mixture of carbonaceous, argillaceous, and sandy shale. It is blackish-gray in appearance, hard in texture, and has a low carbon content. Its calorific value is typically less than 6.3 MJ / kg. Its microscopic surface is rough, and its shapes vary, mostly in massive form. Its mineral composition is similar to coal. The vast majority of excavated coal gangue has a particle size less than 100 mm, while washed gangue generally has a particle size less than 50 mm. It is an inert material. Its chemical composition is mainly Al2O3 and SiO2, and it also contains varying amounts of Fe2O3, CaO, MgO, K2O, and other metal oxides. Minerally, it commonly contains kaolinite and quartz, two crystalline minerals, as well as small amounts of water, carbonaceous matter, weathering products, and other amorphous substances.

[0003] Premixed fluidized solidified soil filling engineering refers to the engineering technology of using fluidized solidified soil, a new type of environmentally friendly building material, for filling operations. Traditional soil materials for premixed fluidized solidified soil include undisturbed soil, excavated soil, waste construction mud, tailings, stone chips, recycled construction waste, loam, and miscellaneous fill. The solidifying agent typically consists of active Al2O3, SiO2, and CaO as the main components, mixed with a certain proportion of activators and agents that improve the surface properties of soil particles, forming a composite cementitious material. Currently, there are no known applications of premixed fluidized solidified soil prepared primarily from coal gangue in filling engineering.

[0004] The information in the background section is merely intended to illustrate the general background of the invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] To address at least some of the technical problems in the prior art, this invention provides a premixed coal-based solid waste fluidized solidification material, the resulting product, and corresponding preparation and construction methods. Specifically, it includes the following:

[0006] A first aspect of this application provides a premixed coal-based solid waste fluidized solidification material, comprising aggregates and a solidifying agent, but excluding a retarder, wherein:

[0007] The coal-based solid waste refers to coal gangue waste generated during the construction, development, mining, or coal washing processes of coal mines.

[0008] All the aggregates are coal-based solid waste aggregates, including coarse aggregates with a particle size of 5-10 mm, fine aggregates with a particle size of 2-5 mm, and micro aggregates with a particle size of 0.075-2 mm. The coarse aggregates are 10-30 parts by weight, the fine aggregates are 30-45 parts by weight, and the micro aggregates are 30-55 parts by weight. There are no other aggregates.

[0009] The curing agent is composed of powder obtained by crushing the coal-based solid waste to particles smaller than 0.075 mm and cement, and the curing agent accounts for 1-20% of the weight of the aggregate.

[0010] The initial setting time of the fluidized solidified soil obtained by mixing the premixed coal-based solid waste fluidized solidification material with water is more than 4 hours.

[0011] In some embodiments, the premixed coal-based solid waste fluidized solidification material according to the first aspect, wherein the dry basis ash content of the coal-based solid waste is >50%.

[0012] In some embodiments, the premixed coal-based solid waste fluidized solidification material according to the first aspect, wherein the coal gangue is tunneling coal gangue and / or washed coal gangue.

[0013] In some embodiments, the premixed coal-based solid waste fluidized solidification material according to the first aspect, wherein the powder accounts for 20-80% based on the total weight of the solidifying agent.

[0014] In some embodiments, the premixed coal-based solid waste fluidized solidification material according to the first aspect, wherein the powder accounts for 25-50% based on the total weight of the solidifying agent.

[0015] In some embodiments, the premixed coal-based solid waste fluidized solidification material according to the first aspect is wherein the moisture content of the coal-based solid waste is less than 10%.

[0016] A second aspect of this application provides a method for preparing a building material, comprising the step of mixing the premixed coal-based solid waste fluidized solidification material described in the first aspect with water.

[0017] A third aspect of this application provides a building material prepared by the method described in the second aspect.

[0018] In a preferred embodiment, the building material of this application exists in the form of pre-mixed fluidized solidified soil before solidification; or it exists in the form during or after solidification.

[0019] A fourth aspect of this application provides a method for constructing a filling project, comprising the processes of producing, using, and / or transporting the building materials described in this application.

[0020] This application develops a comprehensive utilization scheme for coal gangue, requiring only simple processing such as crushing and screening to achieve nearly 100% low-cost, high-efficiency, and high-value utilization of coal gangue. Furthermore, the preparation of the fluidized solidified product requires only the addition of cement, optional fly ash, and a suitable amount of water, without any other components. The performance of the prepared fluidized solidified product far exceeds the standards of general fluidized solidified soil and conventional construction standards. It can be applied to the stabilization and solidification of cavities, pits, trenches, culverts, and soil layers; non-load-bearing filling of the interior and upper spaces of buildings and structures; and backfilling projects with strict construction requirements, such as abutments, culvert backs, and wall backs in transportation engineering, truly realizing high-value reuse of solid waste. Detailed Implementation

[0021] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0022] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0023] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0024] In this document, the term "premixed fluidized solidification material," sometimes simply referred to as "solidified material," refers to a filling material that is centrally mixed in a factory and transported to the construction site by specialized vehicles. It is a composition or mixture consisting of aggregates with a certain amount of curing agent added. A composition refers to a material in which each component, or at least some of the components, exists in a separate form; for example, aggregates may be in individual packages, while the solidified material may be in a separate package. A mixture refers to a material in which the components coexist.

[0025] In this document, the term "fluidized solidification product" refers to an engineering material obtained using the premixed fluidized solidification material of this application, for example, by first mixing some or all of the components in the fluidized solidification material in composition form, adding water and mixing, and optionally further adding other components and mixing evenly; or by directly adding water to the fluidized solidification material in mixture form and mixing and homogenizing. This forms an engineering material with a certain fluidity that, after solidification, achieves certain strength and permeability requirements. That is, a fluidized engineering material formed by adding water to a fluidized solidification material, or a solidified material formed after solidification. This document sometimes also refers to it as "fluidized solidified soil" or "solidified soil."

[0026] In this article, the term "curing agent incorporation ratio" refers to the ratio of the mass of curing agent to the dry mass of the aggregate used, expressed as a percentage.

[0027] [Premixed coal-based solid waste fluidized bed solidification materials and products]

[0028] One aspect of this application, based on the concept of comprehensive utilization of all components of coal-based solid waste, allows for 100% high-value utilization of all coal-based solid waste through simple processing such as crushing and screening. The pre-mixed coal-based solid waste fluidized bed material of this application includes coal-based solid waste aggregate and a solidifying agent, wherein the coal-based solid waste aggregate comprises 100 parts by weight, and the coal-based solid waste solidifying agent comprises 1-20 parts by weight, and the solidifying agent contains solidifying agents derived from coal-based solid waste.

[0029] In this application, to meet the required performance requirements, the particle size of the coal-based solid waste aggregate needs to be controlled within a specific range, typically below 10 mm. In this application, the coal-based solid waste aggregate uses aggregate grades with different particle size ranges and specific proportions. Preferably, it includes three different grades, for example, coarse aggregate in the range of 5-10 mm, fine aggregate in the range of 2-5 mm, and micro aggregate in the range of 0.075-2 mm.

[0030] In this application, most of the raw particles of coal-based solid waste, especially coal gangue, are between 50mm and 100mm, requiring crushing. The finer the crushing, the higher the cost. Therefore, although the proportion of the three grades in the coal-based solid waste aggregate is not specifically limited, from the perspective of economic and fluidity balance, the proportion of coarse aggregate should not be too high (otherwise the setting time will be too short, affecting construction) nor too low (otherwise the fluidity will be poor), and is usually controlled at 10-30 parts by weight. For example, 15 parts by weight, 20 parts by weight, and 25 parts by weight.

[0031] In this application, the addition of fine aggregate and micro aggregate is crucial for achieving the purpose of this application. A lack of these aggregates significantly reduces the fluidity of the cured material and may lead to construction problems such as localized premature setting or uneven setting. The amount of fine aggregate is typically 30-45 parts by weight (preferably 35, 40, or 42 parts), and the amount of micro aggregate is 30-55 parts by weight (e.g., 32, 35, 40, 45, or 50 parts); excessive amounts may negatively affect fluidity. Generally, the amount of fine aggregate is greater than that of coarse aggregate, and the amount of micro aggregate is greater than that of fine aggregate. The addition of fine and micro aggregates is necessary for achieving the purpose of this application.

[0032] In this application, different grades of aggregate can be obtained by vibration through sieves of different apertures or types. For example, depending on the raw materials, they can first be transported by conveyor belt to different vibrating screens for initial screening. Then, the residue is crushed or pulverized as needed to obtain the required aggregate or powder.

[0033] In this application, the powder particles are smaller than 0.075 mm. Due to the excessively low particle size, adding it alone to a curing agent would cause a significant decrease in fluidity, and traditionally it would be discarded or disposed of separately. However, this application discovers that when such powder is combined with traditional curing agents such as cement, the setting time of the material can be extended, which can precisely compensate for the problem of shortened setting time caused by a high proportion of coarse aggregate, thereby achieving comprehensive utilization of all components.

[0034] In this application, the proportion of powder is generally 10-80% based on the total weight of the curing agent, such as 20%, 30%, 40%, 50%, 60%, 70%, etc. If the proportion is too low, the extension of setting time tends to be insufficient, thus affecting the increase of coarse aggregate usage. On the other hand, if the proportion of powder is too high, the fluidity tends to be insufficient, which may affect construction, especially pipeline transportation.

[0035] In some embodiments, the aggregate of the present invention has a moisture content of less than 10%, in which case a relatively small amount of powder can be used, for example, 40%, preferably 30%. In some embodiments, the aggregate of the present invention has a moisture content of 10% or more, for example, 12% or more, 15% or more, or 18% or more. In this case, a relatively high amount of powder can be used, for example, 50% or more, preferably 55% or more. In some embodiments, the aggregate of the present invention has a moisture content of 10% or more, in which case a higher amount of curing agent can be used.

[0036] In this application, the curing agent, in addition to the powder used in this application, must further include curing agent components. The type of such curing agent components is not limited; any product known in this application can be used, examples of which include cement, quicklime, and power plant slag. This application may use one or more combinations of the above-mentioned components.

[0037] [Preparation Method]

[0038] In another aspect, this application provides a method for preparing a premixed coal-based solid waste fluidized solid product. Any method that includes the step of mixing the premixed coal-based solid waste fluidized solid material described in this application with water is within the scope of this application's preparation method. Optionally, it may further include a step of preparing aggregates from coal-based solid waste, aggregate proportioning, and other preparatory steps.

[0039] In this application, the aggregate preparation step can be carried out using conventional methods, or new aggregate processing methods can be developed for this purpose. Exemplary methods include:

[0040] Crushing steps, for example:

[0041] Primary crushing: Coal gangue with a particle size exceeding 200mm is fed into the jaw crusher via a vibrating feeder and a gangue conveyor belt, with a target particle size of 10mm; after crushing, it is screened by a vibrating screener, and aggregates <10mm are conveyed to a roller crusher for secondary crushing, while gangue >10mm is returned to the jaw crusher for re-crushing.

[0042] Secondary crushing: The double-roll crusher crushes the gangue to the target particle size of 5mm. After screening, some of the aggregate is used to obtain 2-5mm fine aggregate, while the other part is conveyed to the overflow ball mill for tertiary crushing.

[0043] Tertiary crushing: The ball mill grinds the aggregate into powder, which is then sieved to obtain powder with a particle size of <0.075mm.

[0044] Proportioning and mixing steps: Different graded aggregates are fed into the mixing tank through a batching machine for initial mixing according to a specific ratio. The water pump is turned on to supply tap water from the water storage tank. The water injection volume is controlled by a flow counter (so that the solid mass concentration is 45%-60%). The solid-liquid mixture is continuously stirred evenly in the mixing tank.

[0045] In some implementations, coal gangue with a particle size exceeding 200 mm is used, and the particle size is reduced and the gradation optimized through crushing. In cases of redundant aggregate grades, coarse and fine aggregates for road base courses can also be produced concurrently. For example, coal gangue is crushed and transported by conveyor to a vibrating screen for screening to obtain coarse aggregate with a particle size less than 10 mm. Aggregate larger than 10 mm is returned to the crusher for further crushing. The coarse aggregate is further pulverized using a roller mill, and after screening, fine aggregate with a particle size less than 5 mm is obtained. A portion of the fine aggregate is then sent to a ball mill for tertiary pulverization into powder, which is then screened to obtain powder with a particle size less than 0.075 mm.

[0046] In some embodiments, this application provides a method for preparing a coal-based solid waste fluidized solidification product, which further includes the steps of adjusting the proportion of powder in the solidifying agent according to the moisture content of the aggregate, and / or increasing the incorporation ratio of the solidifying agent according to the moisture content of the aggregate. In this case, the method of this application can also be referred to as a method for improving the setting time (especially the initial setting time) of a coal-based solid waste fluidized solidification product.

[0047] [Construction Method]

[0048] In another aspect, this application provides a construction method, which is within the scope of the construction method of this application as long as it involves the production, use and / or transportation of the premixed coal-based solid waste fluidized solidification material or the premixed coal-based solid waste fluidized solidification product described in this application.

[0049] In some implementations, the construction method of this application includes mixing the materials centrally in a factory and then transporting them to the construction site by special vehicles.

[0050] In some embodiments, the construction method of this application includes pouring the prepared fluidized solidified soil in layers 20-30cm thick, utilizing its self-compacting properties to reduce the number of vibrations, and covering it with geotextile and watering it after pouring. In some embodiments, the construction method of this application includes: first using fluidized solidified soil (wet density 1600kg / m³) to seal the seepage points of the foundation pit, and then pouring backfill in sections, controlling the thickness of each pouring layer to be 2-3 meters, with a 24-hour interval between two pours to accumulate heat of hydration.

[0051] Example 1

[0052] This example is a mix proportion test case of coal gangue aggregate (or soil material).

[0053] 1. Coal gangue pretreatment

[0054] The excavated gangue used has the following specifications: SO3 content ≤1.0%, loss on ignition ≤20%, organic matter content <5%, total oxide (SiO2+Al2O3+Fe2O3) content ≥80%, and moisture content <10%. Before use, tree roots, humus, domestic waste, and industrial waste are removed. A combination of jaw crusher and vibrating screen is used. After crushing, the material is screened in four stages (10mm, 5mm, 2mm, and 0.075mm) to obtain continuous four-stage aggregates: coarse aggregate (5-10mm), fine aggregate (2-5mm), micro-aggregate (0.075-2mm), and powder (<0.075mm).

[0055] 2. Curing agent

[0056] Ordinary Portland cement of grade PO42.5 and the powder obtained in step 1 (dry powder) were used.

[0057] 3. Aggregate proportion

[0058] In the aggregate proportioning test, coarse aggregate, fine aggregate, and powder were used as the three factors in the orthogonal experiment, with three test levels set for each factor. The proportions were: coarse aggregate 20-30%, fine aggregate 30-45%, and powder 3-7%. The prepared aggregates and powders were mixed according to the proportions specified in the three-factor, three-level orthogonal experiment, and stirred thoroughly using a mixer to obtain an aggregate mixture. Water was added to the aggregate mixture, and after thorough mixing, a curing agent (a mixture of PO42.5 cement and powder) was added to the aggregate mixture at a ratio of 10%, controlling the water addition to maintain a water-to-solid ratio of 0.5. Data were processed using SPSS.

[0059] Table 1 Results of orthogonal test on aggregate gradation

[0060]

[0061] Note: All percentages in the table are based on the total mass of the aggregate mixture, where coarse aggregate + fine aggregate + micro aggregate totals 100%; curing agent (i.e., powder + cement) totals 10%, and only the percentage of powder is shown in the table; setting time was measured in a greenhouse and the value is rounded to the nearest whole number.

[0062] As shown in Table 1 above, the slump of the fluidized solidified soil obtained from each test group was above 160 mm, meeting the basic requirements for pipeline transportation. Furthermore, according to the basic requirements of most construction standards such as DB1310 / T298-2023, the initial setting time of fluidized solidified soil should be ≥45 minutes, and the final setting time should be <720 minutes. The setting times of the fluidized solidified soil in each of the above test groups all meet this basic requirement. Not only do the performance parameters of the fluidized solidified soil in each test group meet the requirements under on-site mixing conditions, but the fluidized solidified soil of this application also meets the requirements under certain special and more stringent construction conditions. For example, considering the complexity of actual construction, it is necessary to produce pre-mixed fluidized solidified soil at the production site and then carry out construction on-site far from the production site. In this case, the initial setting time should generally be controlled to be above 4 hours.

[0063] The fluidized solidification material of this application can be applied to backfilling of cavities, pits, trenches, culverts, soil stabilization and solidification, and non-load-bearing filling of the interior and upper spaces of buildings and structures, as well as backfilling of abutments, culverts, and walls in transportation engineering. For these application categories, most construction standards require higher fluidity. For example, for general fluid mixtures, the fluidity is generally above 160mm, such as 180mm-220mm. For highly fluid mixtures, a fluidity greater than 220mm is required. Under this stringent application scenario, considering fluidity and setting time, test group 5 was confirmed as the optimal mix proportion. Subsequent tests were conducted based on the mix proportion of test group 5.

[0064] Example 2

[0065] This embodiment is used to test the effect of adding fly ash on the properties of premixed fluidized solidification materials.

[0066] Premixed fluidized solidification material was prepared according to the formulation shown in Table 2 below. Specifically, aggregates of all grades were mixed evenly using a mixer to obtain an aggregate mixture. Water was added to the aggregate mixture, and after stirring evenly, a curing agent (a premix of PO42.5 cement, fly ash, and / or powder) was added to the aggregate mixture at a curing agent incorporation ratio of 10%, controlling the amount of water added to maintain a water-to-solid ratio of 0.5.

[0067] Table 2 Results of fly ash addition test

[0068]

[0069] Note: Percentages in the table are based on the total mass of the aggregate mixture; compressive strength values ​​are rounded to two decimal places.

[0070] As shown in Table 2 above, compared with test group 1, when an appropriate amount of fly ash was added to form a three-component curing agent (test group 2), although the fluidity and early strength of the solidified soil decreased, the later compressive strength was greatly improved. Therefore, similar to powder, fly ash can compensate for the later strength, greatly improving the strength after 28 days. In addition, when fly ash was used to replace all the powder, i.e., when a two-component curing agent was formed (test group 3), the 28-day compressive strength decreased significantly, indicating that the three-component curing agent (test group 2) worked together to achieve high strength in the later stage. When the fluidity of the solidified soil obtained by the two-component curing agent (test group 1) was further reduced compared with the corresponding fluidity obtained by the three-component curing agent (test group 2), it indicated that the powder with a specific particle size in this application has a stronger effect on improving fluidity.

[0071] Example 3

[0072] This embodiment is used to test the effect of aggregate moisture content on the properties of premixed fluidized solidification materials.

[0073] 1. Formulation of fluidized solidification materials

[0074] Aggregate composition: 25% coarse aggregate, 35% fine aggregate, and 40% micro-aggregate;

[0075] Hardener: 3% powder, 7% PO42.5 cement, admixture ratio 10%;

[0076] Water-to-solid ratio: 0.5.

[0077] 2. Effect of moisture content in aggregate composition

[0078] The moisture content of the aggregate composition was controlled according to the table below to prepare fluidized solidified soil, and its properties were measured. The results are shown in Table 3.

[0079] Table 3 Results of Moisture Content Test

[0080]

[0081] Note: Condensation time was measured in the greenhouse and the value was rounded to the nearest whole number.

[0082] Table 3 shows that the moisture content of the aggregate composition affects the initial setting time of the resulting fluidized solidified soil. When the aggregate moisture content is increased to 14 ± 0.2%, the initial setting time decreases by approximately 11%, while having no substantial effect on the final setting time. Furthermore, when the moisture content is further increased, the initial and final setting times do not change substantially. In addition, changes in the moisture content of the aggregate composition also have no substantial effect on the fluidity.

[0083] Based on the investigation of the influence of aggregate moisture content on the initial setting time of fluidized solidified soil, this application further attempts to optimize the formulation and admixture ratio of the curing agent. See Table 4 for details.

[0084] Table 4 Results of the formulation optimization test (25℃)

[0085]

[0086] Note: All percentages in the aggregate mixture are based on the total mass of the aggregate mixture; setting time was measured in a greenhouse and the value was rounded to the nearest whole number.

[0087] Table 4 shows that the results of test group 2 indicate that, with a constant curing agent admixture ratio, simply increasing the proportion of powder does not substantially prolong the initial setting time; instead, it causes a decrease in the final setting time, possibly due to a reduction in cement content. The results of test group 3 indicate that, with a constant curing agent admixture ratio, using fly ash instead of the powder in this application not only fails to prolong the initial setting time but actually shortens it. Therefore, the ability of powder to prolong setting time may be due to its specific chemical composition or particle size. The results of test group 4 indicate that increasing the amount and admixture ratio of powder can significantly prolong the initial setting time. In conclusion, the problem of decreased initial setting time caused by aggregate moisture content can be compensated for by optimizing the curing agent formulation and admixture ratio, with appropriately increasing the proportion of powder in the curing agent showing a significant effect.

[0088] Furthermore, the slump data shows that the fluidity did not change significantly during the above-mentioned formulation optimization process, indicating that the formulation optimization in this application will not have an adverse effect on the fluidity.

[0089] Comparative example

[0090] To demonstrate the performance advantages of the formulation in this application, this application also prepared fluidized solidified soils using conventional coal gangue aggregate (particle size <10mm, 78% residue on a 5mm sieve) and selectively omitting one or two of the three aggregates. Except for the different aggregate composition, all other aspects were the same as in test group 5 of Example 1. The performance results of the obtained fluidized solidified materials are shown in Table 5.

[0091] Table 5. Performance results of cured materials obtained with different aggregates

[0092]

[0093] Note: Percentages are based on the total mass of the aggregate mixture, with the sum of coarse aggregate, fine aggregate, and micro aggregate totaling 100%; setting time was measured in a greenhouse and the value was rounded to the nearest integer.

[0094] As shown in Table 5 above, under the same conditions, the fluidized solidified soil prepared using conventional coal gangue aggregate is inferior to the formulation of this application in terms of fluidity, setting time, and compressive strength. Furthermore, the performance of the fluidized solidified soil deteriorates when there is a gradient difference in particle size among different aggregates. The compaction degree of the test group in Example 1 of this application is 1.65 g / cm³. 3 The density of the comparative example was significantly lower than that of this application.

[0095] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. Various adjustments or changes may be made to the exemplary embodiments described in this specification without departing from the scope or spirit of the invention. The scope of the claims should be interpreted in the broadest possible sense to cover all modifications and equivalent structures and functions.

Claims

1. A premixed coal-based solid waste fluidized solidification material, characterized in that, Includes aggregates and curing agents, but excludes retarders, wherein: The coal-based solid waste refers to coal gangue waste generated during coal mine construction, development and tunneling, coal mining or coal washing, and its moisture content is less than 10%. All the aggregates are coal-based solid waste aggregates, including coarse aggregates with a particle size of 5-10 mm, fine aggregates with a particle size of 2-5 mm, and micro aggregates with a particle size of 0.075-2 mm. The coarse aggregates are 10-30 parts by weight, the fine aggregates are 30-45 parts by weight, and the micro aggregates are 30-55 parts by weight. The amount of micro aggregates is greater than that of fine aggregates. Apart from these, there are no other aggregates. The curing agent is composed of powder obtained by crushing the coal-based solid waste to particles smaller than 0.075 mm and cement. Based on the total weight of the curing agent, the powder accounts for 25-40% and the curing agent accounts for 1-20% of the weight of the aggregate. The fluidized solidified soil obtained by mixing the premixed coal-based solid waste fluidized solidification material with water has an initial setting time of more than 4 hours, a final setting time of less than 720 minutes, and a slump of more than 160 mm.

2. The premixed coal-based solid waste fluidized solidification material according to claim 1, characterized in that, The dry ash content of the coal-based solid waste is >50%.

3. The premixed coal-based solid waste fluidized solidification material according to claim 2, characterized in that, Coal gangue refers to tunneling coal gangue and / or washed coal gangue.

4. A method for preparing a building material, characterized in that, The step includes mixing the premixed coal-based solid waste fluidized solidification material according to any one of claims 1-3 with water.

5. A building material prepared by the method of claim 4.

6. The building material according to claim 5, characterized in that, It exists in the form of pre-cured premixed fluidized solidified soil; or it exists in the form of solidification process or after solidification.

7. A construction method for a filling project, characterized in that, This includes the processes of producing, using, and / or transporting the building materials as described in claim 5 or 6.

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