Multi-source solid waste filling slurry and preparation method thereof

Abstract

The present invention discloses a multi-source solid waste filling slurry and a preparation method thereof, which belongs to the technical field of green filling mining of coal mines. The raw materials of the multi-source solid waste filling slurry include: multi-source solid waste materials, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid; the raw materials of the multi-source solid waste materials include: tailings, desulfurization gypsum, fly ash and gasification slag. The raw materials used in the present invention are all green and environmentally friendly raw materials, and the cost of various types of solid waste materials is low. No cement needs to be added in the entire preparation process, which effectively reduces the cost of coal mine filling mining, and efficiently and rationally uses various types of solid waste materials, reduces surface accumulation, and vigorously promotes the green mining process of coal, providing a new green filling path for cemented filling mining, and has extensive social and economic benefits in ensuring safe and low-cost mining of mines.

Description

Technical Field

[0001] The present invention relates to the technical field of green filling mining of coal mines, and in particular to a multi-source solid waste filling slurry and a preparation method thereof. Background Art

[0002] Against the backdrop of today's growing energy demand, coal, as a conventional energy source with abundant reserves, widespread distribution, and relatively low prices, plays a vital role in numerous industries, including electricity, metallurgy, building materials, and chemicals. However, with the continued development of coal resources, a series of serious problems have gradually emerged. The emergence of mine goafs often leads to surface subsidence and unstable mine pressure. Ground subsidence and collapse in goafs can easily cause major disasters such as mine instability, posing a serious threat to the safety of mining areas and surrounding areas. Furthermore, the use of coal generates a large amount of industrial solid waste, which not only consumes valuable land resources but also causes significant pollution to the ecological environment.

[0003] To address the problem of mining subsidence, mine filling technology has emerged. Mine filling requires large quantities of high-quality filling materials, and currently available mine filling materials primarily consist of mixed slurries of gangue, cement, and fly ash. However, cement, as a commonly used binder, is relatively expensive, and its extensive use will undoubtedly significantly increase the cost of mine filling. Furthermore, the cement production process produces large amounts of carbon dioxide, making its extensive use detrimental to environmental protection. Furthermore, the mechanical properties of filling materials using cement as a binder need to be improved. Therefore, developing an economical and excellent mechanically performing filling material has become a top priority.

[0004] Furthermore, with the rapid development of industry and the continuous evolution of cities, the production of industrial solid waste is increasing daily. The massive accumulation of these industrial solid waste materials not only occupies a large amount of land resources but also becomes a serious source of pollution, causing significant harm to the environment and ecology. The rational utilization of industrial solid waste has become a key issue that needs to be addressed.

[0005] In summary, if we can use industrial solid waste as the main raw material to develop an economical, efficient and environmentally friendly mine filling material that does not use cement, it will have great development prospects. Summary of the Invention

[0006] The purpose of the present invention is to provide a multi-source solid waste filling slurry and a preparation method thereof to solve the problems existing in the above-mentioned prior art. The multi-source solid waste filling slurry uses tailings, desulfurization gypsum and gasified slag as aggregates, and water-based epoxy resin and its curing agent, water-based acrylic resin, polyacrylic acid and fly ash as gelling materials. It makes full use of multi-source solid waste materials and combines the excellent properties of water-based epoxy resin, water-based acrylic resin and polyacrylic acid to obtain a low-cost, high-performance filling slurry, which provides an economical, efficient and environmentally friendly solution for mine filling. The multi-source solid waste filling slurry uses a variety of industrial solid waste materials as the main components, and can efficiently utilize multi-source solid waste to achieve the best rationality of solid waste filling.

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

[0008] One of the technical solutions of the present invention: a multi-source solid waste filling slurry, the raw materials of which include: multi-source solid waste materials, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid;

[0009] The raw materials of the multi-source solid waste materials include, by mass percentage, 38-45% tailings, 18-24% desulfurized gypsum, 19-24% fly ash and 11-15% gasified slag;

[0010] The sum of the mass of the waterborne epoxy resin and the curing agent is 7.5-12.5% of the mass of the multi-source solid waste material;

[0011] The mass of the water-based acrylic resin is 2-5% of the mass of the multi-source solid waste material;

[0012] The mass of the polyacrylic acid is 0.5-1% of the mass of the multi-source solid waste material.

[0013] The filling slurry of the present invention uses multi-source solid waste materials composed of tailings, desulfurization gypsum, fly ash and gasification slag as main raw materials. The microscopic morphology of tailings is generally a regular block structure, with a rough surface and a high specific surface area. Its particle size is large, and it is the solid waste material with the largest amount used in the filling slurry. Tailings not only play a role in skeleton support, but also, due to the microscopic characteristics of its surface, contribute to the effective attachment of hydrated gelling materials such as water-based epoxy resin, thereby improving the overall bonding strength and structural stability of the filling body. The microscopic morphology of desulfurization gypsum is generally an irregular plate-like or sheet-like structure, which is conducive to its mutual interlaced superposition in the filling slurry system, providing the filling slurry system with certain structural stability and filling properties. And its specific surface area is large, which can better undergo physical adsorption and chemical reaction with other substances (such as gelling materials, etc.), promote the coagulation and hardening process of the material, and enhance the overall strength and durability of the material. Fly ash is generally spherical in shape, with a relatively smooth surface and a porous structure, which allows it to absorb more hydration products, thereby improving the strength and durability of the fill. Fumed slag exhibits irregular, blocky micromorphology, a porous structure, and a rough surface. These characteristics give fumed slag excellent filling, adsorption, strength support, and chemical reactivity in fill, enhancing fill performance. The use of these multi-source solid waste materials lays the foundation for the excellent mechanical properties of fills prepared using fill slurries. Furthermore, the synergistic effect of the water-based epoxy resin and its curing agent used in the fill slurry effectively improves the performance of the solid waste materials. The water-based epoxy resin plays a key role in the fill slurry as a bonding and reinforcement agent. Its excellent bonding properties enable it to tightly bind various solid waste materials together, forming a strong fill structure. Furthermore, the water-based epoxy resin improves the fill's water resistance, corrosion resistance, and durability. The water-based epoxy resin curing agent, when used in conjunction with the water-based epoxy resin, promotes the epoxy resin's curing reaction, forming a stable three-dimensional network structure, further enhancing the strength and stability of the filling. Water-based acrylic resin has excellent adhesion to solid waste materials such as tailings, fumed slag, desulfurized gypsum, and fly ash, complementing the water-based epoxy resin in strengthening the bond between aggregates and cementitious materials, thereby reducing voids within the filling. Polyacrylic acid provides a higher degree of anchoring for particulate matter, enhancing the stability of the bonded objects and further reducing pores and cracks within the filling, further improving filling performance. This multi-source solid waste filling slurry utilizes a variety of solid waste materials and works in conjunction with the water-based epoxy resin and its curing agent, water-based acrylic resin, and polyacrylic acid. This minimizes the use of water-based epoxy resin and its curing agent without the need for additional activators, significantly reducing filling costs. Specifically, within a specific dosage range and concentration conditions, the specific raw material combination and ratio can further enhance the filling's overall properties, such as compressive strength. The present invention obtains low-cost and high-performance filling slurry without using cement.

[0014] Furthermore, the raw materials of the multi-source solid waste filling slurry also include a defoaming agent; the mass of the defoaming agent is 2% of the sum of the dry matter mass of the multi-source solid waste material, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid.

[0015] Furthermore, the defoaming agent includes organosilicon and tributyl phosphate; the mass ratio of the organosilicon to the tributyl phosphate is 1:2.

[0016] Silicone, as a defoamer, effectively eliminates bubbles generated during the preparation process, improving the density and uniformity of fillings made from multi-source solid waste, thereby enhancing the performance of the fillings. Tributyl phosphate, as a defoamer, works synergistically with silicone to ensure that the filling slurry maintains excellent performance during the preparation process, further reducing the impact of bubbles on the quality of the filling.

[0017] Further preferably, the raw materials of the multi-source solid waste filling slurry include: multi-source solid waste materials, water-based epoxy resin, curing agent, water-based acrylic resin, polyacrylic acid and defoaming agent;

[0018] The sum of the mass of the waterborne epoxy resin and the curing agent is 7.5-10% of the mass of the multi-source solid waste material;

[0019] The mass of the water-based acrylic resin is 4-5% of the mass of the multi-source solid waste material;

[0020] The mass of the polyacrylic acid is 0.75% of the mass of the multi-source solid waste material;

[0021] The mass of the defoaming agent is 2% of the sum of the dry matter masses of the multi-source solid waste materials, the water-based epoxy resin, the curing agent, the water-based acrylic resin and the polyacrylic acid.

[0022] Regarding the dosage of water-based epoxy resin and its curing agent, adding too much will result in excessive costs, while adding too little will affect the performance of the filling. To save costs and meet practical requirements, a water-based epoxy resin and its curing agent should be added to the multi-source solid waste material at a concentration of 7.5-12.5% by weight. More preferably, the addition amount should be 7.5-10%.

[0023] Furthermore, the particle size of the tailings is ≤2.5 mm.

[0024] Furthermore, the mass proportion of the components with a particle size of ≤4.75 mm in the gasified slag is higher than 98%.

[0025] Furthermore, the curing agent is a curing agent for water-based epoxy resin.

[0026] Furthermore, the waterborne epoxy resin is a bisphenol epoxy resin, and the curing agent includes an amine curing agent and / or an acid anhydride curing agent.

[0027] The second technical solution of the present invention: The method for preparing the multi-source solid waste filling slurry comprises the following steps:

[0028] After uniformly mixing the multi-source solid waste material, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid, water is added until the mass concentration of the multi-source solid waste filling slurry is 69-76%, and the mixture is stirred uniformly to obtain the multi-source solid waste filling slurry;

[0029] And / or, after uniformly mixing the multi-source solid waste material, water-based epoxy resin, curing agent, water-based acrylic resin, polyacrylic acid and defoaming agent, add water to the mass concentration of the multi-source solid waste filling slurry to be 69-76%, stir evenly to obtain the multi-source solid waste filling slurry.

[0030] Further preferably, water is added to a mass concentration of the multi-source solid waste filling slurry of 73-76%.

[0031] The third technical solution of the present invention: application of the above-mentioned multi-source solid waste filling slurry in mine filling.

[0032] The present invention discloses the following technical effects:

[0033] (1) The filling slurry of the present invention does not add cement, thus avoiding the large amount of carbon dioxide emissions generated during the cement production process. It is more environmentally friendly and economical than traditional filling slurries that use cement as the main gelling material.

[0034] (2) The raw materials used in the present invention are all green and environmentally friendly raw materials, and various types of solid waste materials are low-cost. No cement needs to be added in the entire preparation process, which effectively reduces the cost of coal filling mining. In addition, various types of solid waste materials are used efficiently and rationally, which reduces surface accumulation and vigorously promotes the green mining process of coal. It provides a new green filling path for cemented filling mining, and has extensive social and economic benefits in ensuring safe and low-cost mining of mines.

[0035] (3) The filling slurry preparation process of the present invention is simple, and the water-based epoxy resin and its curing agent can be diluted arbitrarily by adding water. Therefore, the formula and preparation process can be adjusted according to different engineering scenarios such as mine filling, and it has strong adaptability and flexibility.

[0036] (4) The filling slurry of the present invention uses water-based epoxy resin and its curing agent as the main gelling materials. Compared with traditional organic solvent-based resins, water-based epoxy resin is non-toxic, odorless, and pollution-free, meets environmental protection requirements, and can be used in combination with multi-source solid waste materials, reducing the occupation of land resources and pollution to the environment by industrial solid waste, realizing the recycling of resources, and having significant environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in 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 paying any creative work.

[0038] Figure 1 is the XRD diffraction pattern of the tailings used in the embodiments of the present invention;

[0039] Figure 2 : is a SEM image of the tailings used in the embodiments of the present invention;

[0040] Figure 3 is the XRD diffraction pattern of the desulfurized gypsum used in the embodiments of the present invention;

[0041] Figure 4 This is a SEM image of the desulfurized gypsum used in the examples of the present invention;

[0042] Figure 5 is the XRD diffraction pattern of the fly ash used in the embodiments of the present invention;

[0043] Figure 6 is a SEM image of fly ash used in the examples of the present invention;

[0044] Figure 7 The XRD diffraction pattern of the fumed slag used in the embodiments of the present invention is;

[0045] Figure 8 This is a SEM image of the gasified slag used in the examples of the present invention;

[0046] Figure 9 This is an SEM image of a filling body prepared using the filling slurry prepared in Example 1, with a scale of 20.0 μm;

[0047] Figure 10 This is an SEM image of a filling body prepared using the filling slurry prepared in Example 1, with a scale of 10.0 μm;

[0048] Figure 11 This is an SEM image of a filling body prepared using the filling slurry prepared in Example 1, with a scale of 1.0 μm. DETAILED DESCRIPTION

[0049] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0050] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0051] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0052] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0053] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0054] As a first aspect of the present invention, the present invention provides a multi-source solid waste filling slurry, the raw materials of which include: multi-source solid waste materials, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid;

[0055] The raw materials of the multi-source solid waste materials include, by mass percentage, 38-45% tailings, 18-24% desulfurized gypsum, 19-24% fly ash and 11-15% gasified slag;

[0056] The sum of the mass of the waterborne epoxy resin and the curing agent is 7.5-12.5% of the mass of the multi-source solid waste material;

[0057] The mass of the water-based acrylic resin is 2-5% of the mass of the multi-source solid waste material;

[0058] The mass of the polyacrylic acid is 0.5-1% of the mass of the multi-source solid waste material.

[0059] As a preferred embodiment of the present invention, the raw materials of the multi-source solid waste filling slurry also include a defoamer; the mass of the defoamer is 2% of the sum of the dry matter mass of the multi-source solid waste material, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid.

[0060] As a preferred embodiment of the present invention, the defoaming agent includes organosilicon and tributyl phosphate; the mass ratio of the organosilicon to the tributyl phosphate is 1:2.

[0061] As a preferred embodiment of the present invention, the water-based epoxy resin is a bisphenol-type water-based epoxy resin. A water-based epoxy resin refers to a stable dispersion system obtained by dispersing epoxy resin in the form of particles or droplets in a dispersion medium with water as the continuous phase. Specifically, a water-based epoxy resin is a stable dispersion system that is primarily composed of epoxy resin and is dispersed in water by introducing hydrophilic groups or using emulsifiers. Its main components include epoxy resin and additives such as hydrophilic groups introduced to impart hydrophilicity to the epoxy resin or emulsifiers used. It contains groups such as epoxy and hydroxyl groups.

[0062] As an embodiment of the present invention, the curing agent is a curing agent for waterborne epoxy resin, that is, a substance that can react with waterborne epoxy resin to solidify it, mainly including compounds such as amines and acid anhydrides, mainly containing groups such as amino groups and carboxyl groups.

[0063] As an embodiment of the present invention, the waterborne epoxy resin is the waterborne epoxy resin component in a two-component waterborne epoxy resin, and the curing agent is the curing agent component in the two-component waterborne epoxy resin.

[0064] As an embodiment of the present invention, the water-based acrylic resin is mainly formed by polymerization of acrylic ester monomers and other vinyl monomers, and its main components are acrylic ester, methacrylate, vinyl monomers and water-based monomers.

[0065] As an embodiment of the present invention, the polyacrylic acid is a water-soluble high molecular polymer containing a large number of strong polar groups such as carboxyl groups on the molecular chain, and its chemical formula is (C3H4O2) n .

[0066] As an embodiment of the present invention, the organosilicon is a type of organic compound containing silicon element, which has excellent heat resistance, weather resistance and water resistance, etc. Its main structural feature is containing silicon-oxygen bonds, etc.

[0067] As an embodiment of the present invention, the tailings are waste discharged after a mineral processing plant grinds ore and selects useful components under specific economic and technical conditions. The main crystalline mineral component in the tailings is SiO2.

[0068] As an embodiment of the present invention, the desulfurization gypsum is a by-product produced by thermal power plants, chemical companies, etc. after desulfurization of sulfur-containing flue gas under specific environmental protection technology (limestone-gypsum wet desulfurization) conditions. The main crystalline mineral component in the desulfurization gypsum is CaSO4·2H2O, and other crystalline mineral components include a small amount of CaCO3.

[0069] As an embodiment of the present invention, the fly ash refers to the fine ash collected from the flue gas after coal combustion, which is the main solid waste discharged from coal-fired power plants. The main crystalline mineral component is SiO2, and other crystalline minerals are Al2SiO5, AlPO4, and A12O3.

[0070] As an embodiment of the present invention, the gasified slag is a solid residue formed by the incomplete combustion of coal with oxygen or oxygen-enriched air to generate CO and H2, in which the inorganic minerals in the coal undergo different physical and chemical transformations along with the carbon particles remaining in the coal. The main crystalline mineral components are C 30 H 14 N4O4Zn·2H2O.

[0071] As a preferred embodiment of the present invention, the particle size of the tailings is ≤2.5 mm.

[0072] As a preferred embodiment of the present invention, the mass proportion of components with a particle size of ≤4.75 mm in the gasified slag is higher than 98%.

[0073] As a second aspect of the present invention, the present invention provides a method for preparing the multi-source solid waste filling slurry, comprising the following steps:

[0074] After uniformly mixing the multi-source solid waste material, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid, water is added until the mass concentration of the multi-source solid waste filling slurry is 69-76%, and the mixture is stirred uniformly to obtain the multi-source solid waste filling slurry;

[0075] And / or, after uniformly mixing the multi-source solid waste material, water-based epoxy resin, curing agent, water-based acrylic resin, polyacrylic acid and defoaming agent, add water to the mass concentration of the multi-source solid waste filling slurry to be 69-76%, stir evenly to obtain the multi-source solid waste filling slurry.

[0076] As a preferred embodiment of the present invention, water is added to the multi-source solid waste filling slurry to a mass concentration of 73-76%.

[0077] As a third aspect of the present invention, the present invention provides the use of the above-mentioned multi-source solid waste filling slurry in mine filling.

[0078] The multi-source solid waste filling slurry and its preparation method of the present invention are further described below with reference to specific embodiments.

[0079] The raw materials used in the following examples and comparative examples were all purchased from the market, wherein:

[0080] The XRD diffraction pattern of the tailings used is shown in Figure 1 , SEM images are shown in Figure 2 ,Depend on Figure 1 It can be seen that the maximum diffraction peak appears between 20° and 30° in the XRD diffraction pattern, and there are smaller diffraction peaks at other angles, indicating that the crystalline mineral components in the tailings are mainly SiO2, and the content of other crystalline minerals is relatively small;

[0081] Depend on Figure 2 The SEM image of the tailings shows that the tailings have a relatively regular polyhedral block structure, which can provide a stable skeleton support for the filling body. The surface has obvious concave-convex texture, is relatively rough, and has a large surface area. This allows the tailings to be closely combined with the hydrated gelling material during the filling body formation process, promoting a stronger bonding of the various parts of the filling body, and ultimately forming a higher strength overall specimen.

[0082] The XRD diffraction pattern of the desulfurized gypsum used is shown in Figure 3 , SEM images are shown in Figure 4 ,Depend on Figure 3 It can be seen that the maximum diffraction peak appears between 10° and 55° in the XRD diffraction pattern, and there are other diffraction peaks, indicating that the main crystalline mineral component of desulfurized gypsum is CaSO4·2H2O, and other crystalline mineral components contain CaCO3;

[0083] Depend on Figure 4 The SEM image of desulfurized gypsum shows that its microstructure presents an irregular plate-like or flaky structure. This structure is conducive to interlaced superposition in subsequent applications, providing certain structural stability and filling properties for related material systems. Its surface is relatively smooth, but there are some tiny pores and textures. These pores and textures increase its specific surface area, allowing the desulfurized gypsum to better physically adsorb and chemically react with other substances (such as cementitious materials, additives, etc.) when used as a building material or industrial filler, promoting the coagulation and hardening process of the material and enhancing the overall strength and durability of the material.

[0084] The XRD diffraction pattern of the fly ash used is shown in Figure 5 , SEM images are shown in Figure 6 ,Depend on Figure 5It can be seen that the XRD diffraction pattern has the largest diffraction peak between 20° and 30°, and there are multiple other diffraction peaks between 30° and 45°, indicating that the main crystalline mineral component of fly ash is SiO2, and other crystalline mineral components are A12SiO5, AlPO4, and Al2O3;

[0085] Depend on Figure 6 The SEM image of fly ash shows that the fly ash microstructure is spherical. The surface of these spherical particles is relatively smooth and of different sizes. The surface has a porous structure. The size and shape of these pores are different, so they can absorb more hydration products, thereby improving the strength and durability of the filling body.

[0086] The XRD diffraction pattern of the fumed slag used is shown in Figure 7 , SEM images are shown in Figure 8 ,Depend on Figure 7 It can be seen that the XRD diffraction spectrum has the largest diffraction peak only between 20° and 30°, and it is the only diffraction peak in the spectrum, indicating that the mineral composition of the fumed slag is single, and the main component is C 30 H 14 N4O4Zn·2H2O;

[0087] Depend on Figure 8 The SEM image of the gasified slag shows that the microstructure of the gasified slag is irregular, porous and has a rough surface. These characteristics make the gasified slag have good filling properties, adsorption properties, strength support and certain chemical reaction activity in the filling body, which can improve the performance of the filling body.

[0088] The particle size statistics of the tailings and gasified slag used in the specific examples and comparative examples of the present invention are shown in Table 1 (where % is mass percentage), and the particle size range of other raw materials is not limited.

[0089] Table 1

[0090]

[0091] The water-based epoxy resin used was epoxy emulsion HT-5150, purchased from Hubei Jinshengyuan Environmental Protection Technology Co., Ltd.

[0092] The curing agent used was curing agent G08, purchased from Hubei Jinshengyuan Environmental Protection Technology Co., Ltd.

[0093] The mass ratio of the waterborne epoxy resin to its curing agent in each embodiment and comparative example is 2:1;

[0094] The aqueous acrylic resin used was aqueous acrylic emulsion E0504, purchased from Shenzhen Jitian Chemical Co., Ltd.

[0095] The polyacrylic acid used was polyacrylic acid DL-03, purchased from Jinan Delan Chemical Co., Ltd.

[0096] The organic silicon used was industrial defoamer CI-0560, purchased from Guangdong Nanhui New Materials Co., Ltd.;

[0097] The molecular weight of tributyl phosphate used was 266.31 and was purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd.

[0098] Example 1

[0099] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0100] Multi-source solid waste materials were weighed according to the mass percentages of 45% tailings, 20% desulfurization gypsum, 20% fly ash, and 15% gasification slag, and water-based epoxy resin and its curing agent accounting for 10% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 3% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 0.75% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate (the mass ratio of silicone and tributyl phosphate is 1:2) accounting for 2% of the total mass of dry matter (the sum of the dry mass of multi-source solid waste materials, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid). After mixing the raw materials evenly, an appropriate amount of water was added and stirred to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0101] Example 2

[0102] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0103] Multi-source solid waste materials were weighed according to the mass percentages of 43% tailings, 22% desulfurization gypsum, 20% fly ash, and 15% gasification slag, and water-based epoxy resin and its curing agent accounting for 10% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 3% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 0.75% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2). After mixing the raw materials evenly, add appropriate amount of water and mix and stir to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0104] Example 3

[0105] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0106] Multi-source solid waste materials were weighed according to the mass percentage of 38% tailings, 24% desulfurization gypsum, 24% fly ash, and 14% gasification slag, and water-based epoxy resin and its curing agent accounting for 12.5% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 4% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 1% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2). After mixing the raw materials evenly, add appropriate amount of water and mix and stir to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0107] Example 4

[0108] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0109] Multi-source solid waste materials were weighed according to the mass percentages of 41% tailings, 23% desulfurization gypsum, 23% fly ash, and 13% gasification slag, and water-based epoxy resin and its curing agent accounting for 7.5% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 5% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 0.5% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2). After mixing the raw materials evenly, add appropriate amount of water and mix and stir to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0110] Example 5

[0111] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0112] Multi-source solid waste materials were weighed according to the mass percentage of 42% tailings, 20% desulfurization gypsum, 24% fly ash, and 14% gasification slag, and water-based epoxy resin and its curing agent accounting for 10% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 2% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 0.75% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2) were weighed. After mixing the raw materials evenly, an appropriate amount of water was added and mixed to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0113] Example 6

[0114] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0115] Multi-source solid waste materials were weighed according to the mass percentages of 45% tailings, 19% desulfurization gypsum, 23% fly ash, and 13% gasification slag, and water-based epoxy resin and its curing agent accounting for 12.5% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 3% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 1% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2). After mixing the raw materials evenly, add appropriate amount of water and mix and stir to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0116] Example 7

[0117] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0118] Multi-source solid waste materials were weighed according to the mass percentage of 44% tailings, 22% desulfurization gypsum, 19% fly ash and 15% gasification slag, and water-based epoxy resin and its curing agent accounting for 7.5% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 4% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 0.5% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2) were weighed. After mixing the raw materials evenly, an appropriate amount of water was added and mixed to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 74%.

[0119] Example 8

[0120] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0121] Multi-source solid waste materials were weighed according to the mass percentages of 44% tailings, 18% desulfurization gypsum, 23% fly ash, and 15% gasification slag, and water-based epoxy resin and its curing agent accounting for 10% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 5% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 0.75% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2). After mixing the raw materials evenly, add appropriate amount of water and mix and stir to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0122] Example 9

[0123] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0124] Multi-source solid waste materials were weighed according to the following mass percentages: 43% tailings, 22% desulfurization gypsum, 24% fly ash, and 11% gasification slag. Water-based epoxy resin and its curing agent accounting for 12.5% of the total mass of multi-source solid waste materials, water-based acrylic resin accounting for 2% of the total mass of multi-source solid waste materials, polyacrylic acid accounting for 0.5% of the total mass of multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2) were weighed. After mixing the raw materials evenly, an appropriate amount of water was added and mixed to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0125] Comparative Example 1

[0126] The same as Example 1, except that the mass of tailings and the like is replaced by gasified slag (ie, tailings are not used, and the amount of gasified slag is reduced to 60%).

[0127] Comparative Example 2

[0128] Same as Example 1, except that the desulfurization gypsum and other materials are replaced by tailings.

[0129] Comparative Example 3

[0130] The same as Example 1, the only difference is that the gasification slag and other masses are replaced by desulfurization gypsum.

[0131] Comparative Example 4

[0132] Same as Example 1, except that the desulfurized gypsum is replaced by cement (ordinary Portland cement P.O42.5).

[0133] Comparative Example 5

[0134] The same as Example 1, except that the water-based epoxy resin and its curing agent, as well as polyacrylic acid and the like are replaced by water-based acrylic resin.

[0135] Comparative Example 6

[0136] The same as Example 1, except that the amount of water added was controlled to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 85%.

[0137] Comparative Example 7

[0138] A multi-source solid waste filling slurry, the preparation steps are as follows:

[0139] Multi-source solid waste materials were weighed according to the mass percentages of 55% tailings, 7% desulfurization gypsum, 10% fly ash, and 28% gasification slag, and water-based epoxy resin and its curing agent accounting for 5% of the total mass of the multi-source solid waste materials, water-based acrylic resin accounting for 10% of the total mass of the multi-source solid waste materials, polyacrylic acid accounting for 0.25% of the total mass of the multi-source solid waste filling materials, and silicone and tributyl phosphate accounting for 2% of the total mass of dry matter (the mass ratio of silicone and tributyl phosphate is 1:2). After mixing the raw materials evenly, add appropriate amount of water and mix and stir to obtain a multi-source solid waste filling slurry with a mass concentration (dry matter content) of 73%.

[0140] Comparative Example 8

[0141] Same as Example 1, except that the mass of polyacrylic acid is replaced by water-based acrylic resin.

[0142] Comparative Example 9

[0143] Same as Example 1, except that the waterborne acrylic resin is replaced by waterborne epoxy resin and its curing agent.

[0144] Comparative Example 10

[0145] The same as Example 1, except that equal amounts of waterborne epoxy resin and its curing agent, as well as waterborne acrylic resin and polyacrylic acid are replaced by cement (ordinary Portland cement PO 42.5).

[0146] Comparative Example 11

[0147] Same as Example 1, except that the organosilicon is replaced by tributyl phosphate.

[0148] Test Example 1

[0149] The filling slurries prepared in Examples 1-9 and Comparative Examples 1-11 were respectively prepared into filling bodies, and the compressive strength test was performed. The filling body preparation method is as follows: the filling slurry is slowly poured into a pre-prepared cylindrical mold with a diameter of 50×100 mm. To prevent bubbles from being generated again during the pouring process, the filling slurry is vibrated while pouring. The upper surface is then smoothed with a shovel. The mold after pouring is placed in a cool place and allowed to stand for 2 days. Then, the mold is demolded. After the test piece is removed, it is covered with a disposable plastic film and allowed to stand for (24±2) hours at (20±5)°C. The test pieces are then numbered and demolded. After demolding, the test pieces are first cured in a standard curing room (relative humidity above 92%) for 7 days, and then naturally cured in air (relative humidity 60%) for 28 days to obtain the filling body.

[0150] Figure 9-11 The SEM images of the filling body prepared by the filling slurry of Example 1 at different magnifications are shown in FIG. Figure 9-11It can be seen that under the auxiliary bonding effect of water-based acrylic resin and polyacrylic acid, water-based epoxy resin and curing agent undergo cross-linking reaction to form a continuous three-dimensional network structure on the surface of the solid waste material, which produces an interlayer connection effect on the solid waste material, making it closely connected, greatly reducing the gaps between the solid waste materials, and thus improving the strength of the filling body.

[0151] The uniaxial compressive strength performance of the prepared filling body was measured using a ZSC-107R rock triaxial creep system. The results are shown in Table 2.

[0152] Table 2

[0153]

[0154]

[0155] As can be seen from Table 2, by comparing Example 1 with Comparative Example 1, it can be found that after the tailings are replaced by fumed slag, the filling strength decreases by 66.1%. This is because the tailings, as an important filling aggregate, play a huge role in supporting the filling, while the fumed slag can play a certain macroscopic supporting role, but since its main component is C 30 H 14N4O4Zn·2H2O cannot provide SiO2 for the reaction of the cementitious material, so its macroscopic support effect is weaker than that of tailings. Comparing Example 1 with Comparative Example 2, it can be found that the strength of the filling body decreased by 59.5% when the desulfurized gypsum was replaced with tailings. This is because the tailings have larger particles and a relatively rough surface, and the contact area with the cementitious material is relatively small, and the bonding effect is not as good as that of desulfurized gypsum. As a result, the cementitious material cannot fully exert its bonding and reinforcement effects, resulting in a decrease in the performance of the filling body. Comparing Example 1 with Comparative Example 3, it can be found that the strength of the filling body decreased by 59.7% when the gasified slag was replaced with desulfurized gypsum. This is because the gasified slag may have a higher reactivity and can react chemically with water-based epoxy resin, curing agent, etc. to form a more stable structure, while the reactivity of desulfurized gypsum is relatively low, and the bonding with other materials is not tight enough, which reduces the strength of the filling body. Comparing Example 1 with Comparative Example 4, it was found that replacing desulfurized gypsum with cement decreased the filling strength by 42.5%. This is because cement has a faster hydration reaction rate, which may form a certain strength in the early stage. However, in multi-source solid waste filling, an overly rapid reaction may lead to internal stress concentration, affecting the development of strength in the later stage. Desulfurized gypsum reacts relatively slowly, and may gradually form a stable structure with other materials over a longer period of time, thus giving the filling better long-term strength. Comparing Example 1 with Comparative Example 5, it was found that replacing the water-based epoxy resin and its curing agent with a water-based acrylic resin decreased the filling strength by 49.3%. This is because the bonding effect of water-based acrylic resin is weaker than that of water-based epoxy resin, its curing agent, and water-based acrylic resin. A single water-based acrylic resin cannot effectively bond various solid waste materials together. Comparing Example 1 with Comparative Example 6, it was found that when water was added to the filler at a mass concentration of 85%, the filler strength decreased by 52.9%. This is because excessive water alters the hydration reaction process of various materials in the filler. For fly ash, the hydration reaction is too rapid or uneven, resulting in a loose structure of the resulting hydration product, which cannot provide sufficient strength support. Furthermore, excessive water may also wash away some unreacted gelling materials, such as the water-based epoxy resin and its curing agent, further reducing the filler strength. Comparing Example 1 with Comparative Example 7, it was found that when the raw material dosage in Comparative Example 7 was changed beyond the claimed range, the filler strength decreased by 64.6%, indicating that changing the dosage range reduced the various advantages of the filler slurry. Comparing Example 1 with Comparative Example 8, it was found that replacing polyacrylic acid with a water-based acrylic resin decreased the filler strength by 55.1%. This is because, compared with polyacrylic acid, the water-based acrylic resin forms a less dense and complete network structure in the filler, failing to provide sufficient early strength and later strength growth, resulting in a decrease in the filler's mechanical properties.Comparing Example 1 with Comparative Example 9, it was found that replacing the water-based acrylic resin with a water-based epoxy resin and its curing agent decreased the filling strength by 45.2%. This is because the water-based epoxy resin forms a relatively rigid three-dimensional network structure after curing. When the filling resists external forces or internal stress changes, this rigid structure cannot absorb and disperse stress through deformation as effectively as the water-based acrylic resin. This can easily lead to cracks in the filling even with relatively small deformations, reducing the filling's crack resistance and overall stability. Comparing Example 1 with Comparative Example 10, it was found that replacing the water-based epoxy resin and its curing agent, as well as the water-based acrylic resin and polyacrylic acid, with cement decreased the filling strength by 75.2%. This is because cement primarily bonds particles through the hydration products generated by the hydration reaction. The bond between cement and particles is mainly physical adsorption and weak chemical bonding, and its bonding mode is relatively simple. The bonding effect on particles with smoother surfaces or lower chemical activity, such as tailings, is not as good as with water-based epoxy resins and their curing agents, as well as resin and polymer systems such as water-based acrylic resins and polyacrylic acid. This results in reduced cohesion and integrity of the filling. Comparing Example 1 with Comparative Example 11, it can be seen that replacing silicone with tributyl phosphate reduces the filling strength by 43.6%. This is due to the poor defoaming effect of tributyl phosphate alone, which results in a large number of bubbles remaining within the filling. These bubbles increase the porosity of the filling, loosening the structure, and thus reducing its strength and stability.

[0156] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A multi-source solid waste filling slurry, free of cement, characterized in that: Raw materials include: multi-source solid waste materials, water-based epoxy resin, curing agent, water-based acrylic resin, polyacrylic acid and defoaming agent; The raw materials of the multi-source solid waste materials include, by mass percentage, 38-45% tailings, 18-24% desulfurized gypsum, 19-24% fly ash and 11-15% gasified slag; The sum of the mass of the waterborne epoxy resin and the curing agent is 7.5-12.5% of the mass of the multi-source solid waste material; The mass of the water-based acrylic resin is 2-5% of the mass of the multi-source solid waste material; The mass of the polyacrylic acid is 0.5-1% of the mass of the multi-source solid waste material; The mass of the defoaming agent is 2% of the sum of the dry matter mass of the multi-source solid waste material, water-based epoxy resin, curing agent, water-based acrylic resin and polyacrylic acid; The defoaming agent includes organosilicon and tributyl phosphate; the mass ratio of the organosilicon to the tributyl phosphate is 1:

2.

2. The multi-source solid waste filling slurry according to claim 1, characterized in that: The particle size of the tailings is ≤2.5mm.

3. The multi-source solid waste filling slurry according to claim 1, characterized in that: The mass proportion of the components with a particle size of ≤4.75 mm in the gasified slag is higher than 98%.

4. The method for preparing multi-source solid waste filling slurry according to any one of claims 1 to 3, characterized in that: The following steps are involved: After uniformly mixing multi-source solid waste materials, water-based epoxy resin, curing agent, water-based acrylic resin, polyacrylic acid and defoaming agent, water is added until the mass concentration of the multi-source solid waste filling slurry is 69-76%, and the mixture is stirred uniformly to obtain the multi-source solid waste filling slurry.

5. Use of the multi-source solid waste filling slurry according to any one of claims 1 to 3 in mine filling.

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