Filling cementing material as well as preparation method and application thereof

Abstract

The invention relates to a filling cementing material as well as a preparation method and application thereof. The filling cementing material comprises blast furnace slag powder, fly ash, superfine tailing micropowder, an alkaline activator and a sulfate activator, the specific surface area of the superfine tailing micro powder is 600 to 800 m < 2 > / kg. The technical problem to be solved is how to provide the filling cementing material, the performance of the tailing micropowder can be activated to enhance the bonding effect of the filling cementing material, and the mechanical strength and the cementing effect of the filling cementing material are enhanced through the synergistic effect of the superfine tailing micropowder and other raw materials, so that not only is the industrial solid waste of the tailing treated, but also the economic benefit is improved. And cement is avoided, so that carbon reduction and environmental protection are facilitated.

Description

Technical Field

[0001] The invention belongs to the field of filling materials for mine goafs, and in particular relates to a filling gelling material and a preparation method and application thereof. Background Art

[0002] With the advancement of mineral processing technology, the particles of tailings are becoming finer and finer, among which the proportion of 200-mesh tailings fine powder is increasing. The impact on mine safety production is also increasing, and the requirements for filling cementing materials are also becoming higher and higher. The special cementing materials used by mining companies to fill goaf are mainly 425 cement and special filling cementing materials. Among them, the cost of 425 cement filling is relatively high, the dosage is large, and the cement production process produces a large amount of carbon emissions and causes a lot of pollution to the environment. Special filling cementing materials are generally compounded with materials with volcanic ash activity such as mineral powder. Although special filling cementing materials have the advantages of low cost, small dosage, low hydration heat, and directional research and development, they have problems such as slow early coagulation, poor cementing effect of extremely fine tailings, and low strength.

[0003] Tailings are solid waste generated during the mineral processing process. With the rapid development of mineral processing technology, the amount of tailings solid waste is increasing, and currently, the means of resource recycling remain limited. This leads to the accumulation of tailings solid waste, which not only wastes resources but also occupies land. Because tailings contain various silicates, they have the potential to be used as a cementitious material. However, due to the chemical stability of tailings, the preparation of cementitious materials using tailings as a raw material still requires the addition of a large amount of cement clinker to increase the adhesiveness of the cementitious material.

[0004] In view of the above, how to prepare a special binder for filling mine goaf using tailings fine powder, reduce the amount of cement used in the special binder for filling, and improve environmental protection is an urgent problem to be solved in this technical field. Summary of the Invention

[0005] The main purpose of the present invention is to provide a filling cementitious material and its preparation method and application. The technical problem to be solved is how to provide a filling cementitious material that can utilize tail-end micropowder to reduce the amount of cement used in the special filling binder, and has high mechanical strength and good bonding effect, so that it is more suitable for practical use.

[0006] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical solutions. According to the present invention, a filling gelling material is proposed, and its raw materials include:

[0007] Blast furnace slag powder, fly ash, ultrafine tailings powder, alkaline activator, sulfate activator; the specific surface area of ​​the ultrafine tailings powder is 600-800m 2 / kg.

[0008] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0009] Preferably, the content of the ultrafine tailings powder in the aforementioned filling gelling material is 10-20%, based on the mass of the aforementioned filling gelling material being 100%.

[0010] Preferably, the aforementioned filling gelling material, in terms of mass percentage, contains in the aforementioned ultrafine tailings powder: 55-69% tailings dust collection powder, 30-44% blast furnace slag powder and 0.5-1.5% grinding aid.

[0011] Preferably, the content of the alkaline activator in the aforementioned filling gelling material is 2-10%, based on the mass of the aforementioned filling gelling material being 100%; the aforementioned alkaline activator is composed of quicklime and carbide slag in a mass ratio of 2-3:1.

[0012] Preferably, the content of the sulfate activator in the aforementioned filling cementitious material is 5-15%, based on the mass of the aforementioned filling cementitious material being 100%; the aforementioned sulfate activator is selected from at least one of natural gypsum, desulfurized gypsum, fluorgypsum and phosphogypsum.

[0013] Preferably, the aforementioned filling cementitious material, based on the mass of the aforementioned filling cementitious material being 100%, the content of the aforementioned blast furnace slag powder is 50-70%, and the content of the aforementioned fly ash is 5-15%.

[0014] The purpose of the present invention and the solution to the technical problem are also achieved by adopting the following technical solutions.

[0015] A method for preparing a filling gelling material according to the present invention comprises the following steps:

[0016] The blast furnace slag powder, fly ash, ultrafine tailing powder, alkaline activator and sulfate activator are mixed evenly to obtain a filling gel material; the specific surface area of ​​the ultrafine tailing powder is 600 to 800 m 2 / kg.

[0017] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0018] Preferably, in the method for preparing the aforementioned filling gelling material, tailings dust collection powder, blast furnace slag powder and grinding aid are mixed to form a mixture A, and the mixture is ground to obtain the aforementioned ultrafine tailings powder.

[0019] Preferably, in the aforementioned method for preparing the filling gelling material, the mixture A comprises, by mass percentage, 55-69% tailings dust powder, 30-44% blast furnace slag powder and 0.5-1.5% grinding aid.

[0020] The purpose of the present invention and the technical problems solved therein are also achieved by the following technical solutions: According to the present invention, a mine goaf filling slurry is provided, wherein the mine goaf filling slurry is mixed with the aforementioned filling cementitious material and tailings slurry in a lime-sand mass ratio of 1:4 to 12.

[0021] By means of the above technical solution, the present invention provides a filling gelling material and its preparation method and application, which have at least the following advantages:

[0022] The present invention provides a filling gelling material and a preparation method thereof, wherein tailings dust collecting powder is prepared into a filling gelling material with a specific surface area of ​​600 to 800 m 2 / kg of ultrafine tailings powder destroys the surface structure of the silica / aluminate crystal phase in the tailings, exposes more reaction active sites of the tailings powder, and thus enhances the chemical activity of the tailings powder; further, through the synergistic excitation of alkaline activators and sulfate activators, the dissolution of active aluminum phase and active silicon phase in ultrafine tailings powder, solid waste materials blast furnace slag powder and fly ash is increased, and the active aluminum phase reacts to form ettringite crystals (AFt) under the action of calcium hydroxide and sulfate ions. The ettringite crystals (AFt) use the ultrafine tailings powder as crystal nuclei to quickly form a stable supporting skeleton structure; at the same time, the active silicon phase reacts with calcium hydroxide to form CSH gel, which fills the pores in the supporting structure and produces a cementing effect with the aggregate, eventually forming a filling body with strong strength. In addition, the filling cementitious material provided by the present invention avoids the use of cement and uses solid waste blast furnace slag powder, fly ash, and tailings powder as main raw materials, which not only contributes to environmental protection, but also helps to increase the reuse of solid waste such as tailings, that is, saves resources and reduces production costs.

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a graph showing the specific surface area of ​​the ultrafine tungsten tailings powder in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] To further illustrate the technical means and effectiveness of the present invention in achieving its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, describes a filling gelling material, its preparation method, and its application. The specific implementation, structure, features, and effectiveness of the material are described in detail below.

[0026] Existing technical research has found that although tailings contain a variety of silicates and have the potential to be used as cementitious materials, due to the stable chemical properties of tailings, that is, they are highly inert and have low hydration activity, there is no mature technology on the market to use tailings as raw materials for cementitious materials. Therefore, in the existing technology, tailings are mainly added to filling materials as aggregate components to play a supporting role, and their bonding effect is limited.

[0027] After in-depth research, the inventors found that the main reason for the stable chemical properties and strong inertness of tailings is that they have fewer silicate reaction active sites, which makes it difficult for tailings to combine with other components during use, resulting in weak hydration and thus weak bonding. Based on this discovery, the present invention grinds the tailings into ultrafine tailings powder by grinding, increases the specific surface area of ​​the particles, and makes the specific surface area of ​​the particles reach 600-800m 2 / kg, so that more silicate reaction active sites are exposed on the surface of the structure. Under the action of the activator, the ultrafine tailings powder works synergistically with the blast furnace slag powder and fly ash, which not only increases the bonding effect of the prepared cementitious material, but also improves the mechanical strength of the cementitious material. It can be used as a filling cementitious material and can avoid the use of cement. This not only helps to protect the environment, but also helps to increase the reuse of solid waste such as tailings, that is, save resources and reduce production costs.

[0028] In view of the above, the present invention provides a filling gelling material, the raw materials of which include:

[0029] Blast furnace slag powder, fly ash, ultrafine tailings powder, alkaline activator, sulfate activator;

[0030] The specific surface area of ​​the ultrafine tailings powder is 600 to 800 m 2 / kg.

[0031] In the aforementioned solution, in some embodiments, the blast furnace slag powder is S95 granulated blast furnace slag powder; in other embodiments, the fly ash is Class II fly ash.

[0032] The above-mentioned scheme of the present invention not only effectively enhances the chemical activity of the tailings powder, but also increases the dissolution of the active aluminum phase and the active silicon phase in the ultrafine tailings powder, solid waste materials blast furnace slag powder and fly ash through the synergistic excitation of the alkaline activator and the sulfate activator. The active aluminum phase reacts with calcium hydroxide and sulfate ions to form ettringite crystals (AFt). The ettringite crystals (AFt) use the ultrafine tailings powder as the crystal nucleus to quickly form a stable supporting skeleton structure; at the same time, the active silicon phase reacts with calcium hydroxide to form CSH gel, which fills the pores in the supporting structure and produces a cementing effect with the aggregate, ultimately forming a filling body with strong strength.

[0033] In order to increase the bonding effect and mechanical strength of the prepared filling gelling material, the aforementioned scheme is preferably used in some embodiments. The ultrafine tailings powder is calculated as a percentage by mass and includes: in terms of mass percentage, the ultrafine tailings powder contains: 55-69% tailings dust collection powder, 30-44% blast furnace slag powder and 0.5-1.5% grinding aid. By adopting this technical scheme, on the basis of increasing the specific surface area of ​​the tailings powder, the ultrafine tailings powder can dissolve more active silicon phase in an alkaline environment and form enough reaction sites for ettringite (AFt) crystallization, providing better basic conditions for the rapid formation of a stable supporting skeleton structure.

[0034] In some embodiments of the aforementioned scheme, preferably, the alkaline activator is composed of quicklime and carbide slag in a mass ratio of 2 to 3:1; the sulfate activator is selected from at least one of natural gypsum, desulfurized gypsum, fluorinated gypsum and phosphogypsum; under this condition, the alkaline activator and the sulfate activator can better stimulate the dissolution of ions in blast furnace slag powder, fly ash and ultrafine tailings powder, improve hydration, and form a filling cementitious material with better strength.

[0035] In order to achieve better synergistic effects of the components and enhance the bonding and mechanical strength of the prepared filling gelling material, in some embodiments, preferably, the contents of the components are as follows, in terms of mass percentage:

[0036] 50-70% blast furnace slag powder, 5-15% fly ash, 10-20% ultrafine tailings powder, 2-10% alkaline activator, 5-15% sulfate activator.

[0037] In the aforementioned scheme, in order to avoid the prepared filling cementitious material from self-hydrating and hardening before use due to excessive moisture content in the raw material components, thereby affecting the bonding effect of the filling cementitious material, in some embodiments, preferably, the moisture content of the ultrafine tailings powder, blast furnace slag powder, fly ash, alkaline activator and sulfate activator are all ≤0.5%.

[0038] The present invention also provides a method for preparing a filling gelling material, which comprises the following steps:

[0039] S1: Mix tailings dust powder, blast furnace slag powder and grinding aid to form mixture A, grind to obtain a specific surface area of ​​600-800m 2 / kg of ultrafine tailings powder; the grinding aid is isopropanolamine solution and / or limestone powder; this can not only better maintain the efficacy of each raw material component, but also better reduce the grinding difficulty between particles of different raw material components and improve grinding efficiency; in some embodiments, the mass concentration of the isopropanolamine solution is 20-40%.

[0040] In some embodiments of the aforementioned scheme, the preparation method of tailings dust collection powder is as follows:

[0041] The tailings in the tailings slurry are separated by a filter press process, and wet powder is collected. In some embodiments, preferably, the moisture content of the wet powder is ≤10%, which helps to reduce the cost of the subsequent drying process.

[0042] In order to facilitate the smooth progress of the subsequent grinding process and suppress the hydration of the raw material components during the grinding process, preferably, in some embodiments, the wet powder is dried at 400-500° C. to a moisture content of ≤0.5%, and then the fine tailings powder is collected by a dust collection system to obtain tailings dust collection powder.

[0043] In some embodiments of the above scheme, preferably, the particle size of the tailings dust collection powder is 300-450 meshes, which is conducive to grinding it into the ultrafine tailings powder described in the invention and is also conducive to reducing grinding consumption costs.

[0044] The above scheme is to make it easier to obtain particles with a specific surface area of ​​600 to 800 m 2 / kg of ultrafine tailings powder. In some embodiments, preferably, the aforementioned mixture A comprises, by mass percentage, 55-69% tailings drying dust collection powder, 30-44% blast furnace slag powder and 0.5-1.5% grinding aid.

[0045] S2: Add blast furnace slag powder, fly ash, alkaline activator and sulfate activator to the ultrafine powder and mix them evenly.

[0046] In the aforementioned scheme, since the residual moisture in each raw material component can easily cause hydration of the gelling material raw material during the high-temperature grinding process, and the hydration of the gelling material raw material not only increases the difficulty of the grinding process, but may also affect the gelling effect of the gelling material prepared by the present invention, preferably, in some embodiments, the mixture A is first ground at 20-30°C for at least 8-15 minutes to remove the residual moisture in each raw material component under low temperature conditions, and then the temperature is raised to 70-100°C for grinding. This can improve the grinding efficiency and more easily ensure the inherent efficacy of each raw material component.

[0047] The present invention also provides a mine goaf filling slurry, which is a mixture of the aforementioned filling cementitious material and tailings slurry in a ash-sand mass ratio of 1:4 to 12, wherein the ash mass in the ash-sand mass is the mass of the filling cementitious material, and the sand mass is the solid content of the sand in the tailings slurry. The filling material prepared under this condition has good adhesion and strong mechanical effect.

[0048] The present invention will be further described below with reference to specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0049] Unless otherwise specified, the materials and reagents mentioned below are commercially available products familiar to those skilled in the art. Unless otherwise specified, the methods described are all well-known methods in the art. Unless otherwise defined, technical or scientific terms used shall have the same meanings as those commonly understood by those skilled in the art.

[0050] The specific surface area test, compressive strength test, and flexural strength test methods of the ultrafine tungsten tailings powder in the following embodiments and comparative examples are as follows:

[0051] Specific surface area test of ultrafine tailings powder: In this test, the specific surface area of ​​the ground material is determined with reference to GB / T8074-2008 "Determination of specific surface area of ​​cement - Blaine method".

[0052] Compressive Strength Test: According to the national standard "JGJ / T 70-2009 Standard for Test Methods for Basic Properties of Building Mortar," the weighed materials were poured into a JJ-5 cement mortar mixer and mixed. Stirring was timed for 3 minutes to ensure uniform mixing. The mixing bucket was removed and a test mold was poured. The mold was smoothed and excess slurry was scraped off. The mold was placed in a curing box and cured to the appropriate age for testing. A 70.7*70.7*70.7mm test mold was used for the test.

[0053] Flexural Strength Test: In accordance with the national standard "JGJ / T 70-2009 Standard for Test Methods for Basic Properties of Building Mortar," the weighed materials were poured into a JJ-5 cement mortar mixer and mixed. Stirring was timed for 3 minutes to ensure uniform mixing. The mixing bucket was removed and a test mold was cast. The mold was loaded into the test mold in two layers, vibrating each layer 60 times. The mold was then placed in a curing chamber and cured to the appropriate age for testing. The test mold used was a 40mm x 40mm x 160mm prism, the same as the cement mortar test mold.

[0054] In the following Examples 1 to 4, the tailings dust collection powder comes from tungsten tailings, and the element contents in the tungsten tailings are as follows:

[0055] 60-70% silicon dioxide, 8-15% aluminum oxide, 10-15% calcium oxide, 3-5% iron oxide, 0-5% other elements.

[0056] Example 1

[0057] This embodiment provides a filling gelling material and its preparation method and application, as follows:

[0058] 1) Preparation of tungsten tailings dust powder

[0059] The tailings (coarse) in the tungsten tailings slurry are separated by a filter press process to ensure that the moisture content of the wet powder is 10%; the wet powder is placed in a drying furnace at 400-500°C and dried at a high temperature to a moisture content of 0.5%. The dried fine tailings powder is collected by an air separation dust collection system to obtain tungsten tailings dust collection powder, wherein the particle size of the tungsten tailings dust collection powder is 325-425 mesh.

[0060] 2) Preparation of ultrafine tungsten tailings powder

[0061] Tungsten tailings dust collection powder is mixed with blast furnace slag powder and an active grinding aid (limestone powder) in a mass ratio of 60:39:1. The mixture is then placed in an ultrafine ball mill, and steel grinding balls are added, with a mass ratio of grinding balls to grinding material of 5:1. The mixture is ground at 25°C for 10 minutes, then heated to 80°C and ground for 15 minutes to obtain ultrafine tungsten tailings powder. The element content of the ultrafine tungsten tailings powder in this embodiment is: 49.4% silicon dioxide, 12.5% ​​aluminum oxide, 12.4% calcium oxide, 12.1% iron oxide, and 13.6% other elements.

[0062] The specific surface area of ​​the obtained ultrafine tungsten tailings powder is shown in the attached Figure 1 As shown in the figure, a represents the distribution curve of the number of micropowder particles, and b represents the cumulative distribution curve of the number of micropowder particles. The test results show that the average specific surface area of ​​ultrafine tungsten tailings micropowder particles is 743.4m 2 / kg.

[0063] 3) Preparation of filling gelling materials

[0064] S95 granulated blast furnace slag powder, Class II fly ash, alkali activator (composed of quicklime and carbide slag in a mass ratio of 2.5:1) and sulfate activator (natural gypsum) are all dried to a moisture content of less than 0.5%.

[0065] According to the raw material mass ratio shown in Table 1, dried S95 granulated blast furnace slag powder, Class II fly ash, alkali activator, sulfate activator and ultrafine tungsten tailings powder are weighed, mixed evenly, and then air-blast homogenized to obtain the filling cementitious material described in this embodiment.

[0066] 4) Application of filling cementitious materials

[0067] Raw materials: the filling cementitious material prepared in this example (hereinafter referred to as "filling cementitious material"), tailings slurry, and commercially available 425 cement (purchased from Southern Cement Co., Ltd.).

[0068] Group ingredients:

[0069] Group A: Mix the tailings slurry with the filling cementitious material at a lime-sand mass ratio of 1:4;

[0070] Group B: Mix the tailings slurry with the filling cementitious material at a lime-sand mass ratio of 1:8;

[0071] Group C: Mix the tailings slurry with the filling cementitious material at a lime-sand mass ratio of 1:12;

[0072] Group D: Mix tailings slurry with 425 cement at a lime-sand mass ratio of 1:4;

[0073] Group E: The tailings slurry was mixed with 425 cement at a lime-sand mass ratio of 1:8;

[0074] Group F: Mix the tailings slurry with 425 cement at a lime-sand mass ratio of 1:12.

[0075] Preparation of test blocks:

[0076] The mixtures of groups A to F were subjected to the following process steps:

[0077] The mixed materials were stirred evenly, respectively prepared into filling slurries, injection molded, and made into test blocks, which were cured for 28 days in an environment with a temperature of 20±2°C and a relative humidity of 95%.

[0078] Index detection:

[0079] The compressive strength and flexural strength of the test blocks prepared in each group were measured at 3 days, 7 days, and 28 days during the curing process. The results are shown in Table 2.

[0080] Example 2

[0081] This embodiment provides a filling gelling material and its preparation method and application. The preparation process parameters and steps are basically the same as those in Example 1, except that:

[0082] 1) The raw materials of the filling gelling material prepared in this embodiment are shown in Table 1; and the average specific surface area of ​​the ultrafine tungsten tailings powder particles is 756.3m 2 / kg.

[0083] 2) Application of filling cementitious materials

[0084] Raw materials: the filling gelling material prepared in this example, tailings slurry.

[0085] Group ingredients:

[0086] Group A: Mix the tailings slurry with the filling cementitious material at a lime-sand mass ratio of 1:4;

[0087] Group B: Mix the tailings slurry with the filling cementitious material at a lime-sand mass ratio of 1:8;

[0088] Group C: Mix the tailings slurry with the filling cementitious material at a lime-sand mass ratio of 1:12;

[0089] The remaining steps are the same as those in Example 1, and the detection indicators and methods are the same as those in Example 1. The detection results are shown in Table 2.

[0090] Example 3

[0091] This embodiment provides a filling gelling material and its preparation method and application, as follows:

[0092] 1) Preparation of tungsten tailings dust powder

[0093] The tailings (coarse) in the tungsten tailings slurry are separated by a filter press process to ensure that the moisture content of the wet powder is 8%; the wet powder is placed in a drying furnace at a high temperature of 400-500°C and dried to a moisture content of 0.3%. The dried fine tailings powder is collected by an air separation dust collection system to obtain tungsten tailings dust collection powder, wherein the particle size of the tungsten tailings dust collection powder is 300-425 mesh.

[0094] 2) Preparation of ultrafine tungsten tailings powder

[0095] The tungsten tailings dust collection powder is mixed with blast furnace slag powder and active grinding aid (30% isopropanolamine solution by mass concentration) in a mass ratio of 55:43.5:1.5. The mixture is then put into an ultrafine ball mill and steel grinding balls are added. The mass ratio of grinding balls to grinding materials is 6:1. The mixture is ground at 20°C for 15 minutes, and then the temperature is raised to 100°C and ground for 15 minutes to obtain ultrafine tungsten tailings powder.

[0096] After testing, the average specific surface area of ​​the ultrafine tungsten tailings powder particles obtained is 789.6m 2 / kg.

[0097] 3) Preparation of filling gelling materials

[0098] S95 granulated blast furnace slag powder, Class II fly ash, alkali activator (composed of quicklime and carbide slag in a mass ratio of 2:1) and sulfate activator (desulfurization gypsum) are all dried to a moisture content of less than 0.3%.

[0099] According to the raw material mass ratio shown in Table 1, dried S95 granulated blast furnace slag powder, Class II fly ash, alkali activator, sulfate activator and ultrafine tungsten tailings powder are weighed, mixed evenly, and then air-blast homogenized to obtain the filling cementitious material described in this embodiment.

[0100] 4) Application of filling cementitious materials

[0101] The filling cementitious material prepared in this example was mixed with tailings slurry at a lime-sand mass ratio of 1:4, and test blocks were prepared according to the method described in Example 1 and cured under the same conditions.

[0102] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 2.

[0103] Example 4

[0104] This embodiment provides a filling gelling material and its preparation method and application, as follows:

[0105] 1) Preparation of tungsten tailings dust powder

[0106] The tailings (coarse) in the tungsten tailings slurry are separated by a filter press process to ensure that the moisture content of the wet powder is 9%; the wet powder is placed in a drying furnace at a high temperature of 400-500°C and dried to a moisture content of 0.4%. The dried fine tailings powder is collected by an air separation dust collection system to obtain tungsten tailings dust collection powder, wherein the particle size of the tungsten tailings dust collection powder is 325-450 mesh.

[0107] 2) Preparation of ultrafine tungsten tailings powder

[0108] The tungsten tailings dust collection powder is mixed with blast furnace slag powder and active grinding aid (limestone powder) in a mass ratio of 69:30.5:0.5. The mixture is then put into an ultrafine ball mill and steel grinding balls are added. The mass ratio of grinding balls to grinding materials is 4:1. The mixture is then heated to 70°C and ground for 30 minutes to obtain ultrafine tungsten tailings powder.

[0109] After testing, the average specific surface area of ​​the ultrafine tungsten tailings powder particles obtained is 636.8m 2 / kg.

[0110] 3) Preparation of filling gelling materials

[0111] S95 granulated blast furnace slag powder, Class II fly ash, alkali activator (composed of quicklime and carbide slag in a mass ratio of 3:1) and sulfate activator (phosphogypsum) are all dried to a moisture content of less than 0.4%.

[0112] According to the raw material mass ratio shown in Table 1, dried S95 granulated blast furnace slag powder, Class II fly ash, alkali activator, sulfate activator and ultrafine tungsten tailings powder are weighed, mixed evenly, and then air-blast homogenized to obtain the filling cementitious material described in this embodiment.

[0113] 4) Application of filling cementitious materials

[0114] The filling cementitious material prepared in this example was mixed with tailings slurry at a lime-sand mass ratio of 1:4, and test blocks were prepared according to the method described in Example 1 and cured under the same conditions.

[0115] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 2.

[0116] Example 5

[0117] This embodiment provides a filling gelling material and its preparation method and application. The preparation process parameters and steps are basically the same as those in Example 1. The difference is that the element content of the ultrafine tungsten tailings powder in this embodiment is: 58% silicon dioxide, 6% aluminum oxide, 8% calcium oxide, 10% iron oxide, and 18% other elements. The remaining steps are the same as in Example 1. The average specific surface area of ​​the ultrafine tungsten tailings powder particles obtained is 726.2m 2 / kg.

[0118] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 2.

[0119] Example 6

[0120] This embodiment provides a filling gelling material and its preparation method and application. The preparation process parameters and steps are basically the same as those of Example 1. The difference is that in the preparation process of the ultrafine tungsten tailings powder of this embodiment, the tungsten tailings dust collection powder is mixed with blast furnace slag powder and active grinding aid (limestone powder) in a mass ratio of 60:39:1, and then the mixture is put into an ultrafine ball mill, steel grinding balls are added, and the mass ratio of grinding balls to grinding materials is 5:1. The temperature is directly raised to 80°C and ground for 15 minutes to obtain ultrafine tungsten tailings powder. The remaining steps are the same as those of Example 1. The average specific surface area of ​​the ultrafine tungsten tailings powder particles obtained is 600.3m 2 / kg.

[0121] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 2.

[0122] Example 7

[0123] This embodiment provides a filling gelling material, a preparation method thereof, and an application thereof. The preparation process parameters and steps are basically the same as those of Example 1, except that the moisture content of each component in this embodiment is greater than 1.

[0124] The remaining steps are the same as in Example 1. The average specific surface area of ​​the obtained ultrafine tungsten tailings powder particles is 553.6 m 2 / kg.

[0125] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 2.

[0126] Comparative Example 1

[0127] The difference between this comparative example and Example 1 is that the mass percentage of the raw materials of the prepared filling gelling material is shown in Table 1, and the remaining steps are the same as those of Example 1, and the testing indicators and methods are the same as those of Example 1. The test results are shown in Table 2.

[0128] Comparative Example 2

[0129] The difference between this comparative example and Example 1 is that the mass percentage of the raw materials of the prepared filling gelling material is shown in Table 1, and the remaining steps are the same as those of Example 1, and the testing indicators and methods are the same as those of Example 1. The test results are shown in Table 2.

[0130] Table 1 Mass percentage of filling gelling materials in each embodiment (%)

[0131] Group blast furnace slag powder fly ash Ultrafine tungsten tailings powder Alkali activator Sulfate activator Example 1 60 10 15 10 15 Example 2 50 15 10 10 15 Example 3 70 5 10 5 10 Example 4 65 8 20 2 5 Example 5 60 10 15 10 5 Example 6 60 10 15 10 5 Example 7 60 10 15 10 5 Comparative Example 1 65 10 15 10 0 Comparative Example 2 70 10 15 0 5

[0132] Table 2 Test results of various embodiments and comparative examples

[0133]

[0134] The results of the above examples and comparative examples show that the test blocks prepared by using the filling cementitious material provided by the present invention have good mechanical strength and can be used as a filling cementitious material to fill mined-out areas.

[0135] In Comparative Example 2, due to the lack of alkaline activator, the setting property of the prepared filling gelling material was poor, and the relevant properties of the test blocks prepared therefrom were not further tested.

[0136] The technical features in the claims and / or the specification of the present invention may be combined, and the manner of combination is not limited to the combination obtained by reference in the claims. The technical solutions obtained by combining the technical features in the claims and / or the specification are also within the scope of protection of the present invention.

[0137] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A filling gelling material, characterized in that: Its raw materials include: Blast furnace slag powder, fly ash, ultrafine tailings powder, alkaline activator, sulfate activator; the ultrafine tailings powder has a specific surface area of ​​600 to 800 m 2 / kg.

2. The filling gelling material according to claim 1, characterized in that: Taking the mass of the filling gelling material as 100%, the content of the ultrafine tailings powder is 10-20%.

3. The filling gelling material according to claim 1, characterized in that: Calculated by mass percentage, the ultrafine tailings powder contains: 55-69% tailings dust collection powder, 30-44% blast furnace slag powder and 0.5-1.5% grinding aid.

4. The filling gelling material according to claim 1, characterized in that: Based on the mass of the filling gelling material being 100%, the content of the alkaline activator is 2-10%; the alkaline activator is composed of quicklime and carbide slag in a mass ratio of 2-3:

1.

5. The filling gelling material according to claim 1, characterized in that: Based on the mass of the filling cementitious material being 100%, the content of the sulfate activator is 5-15%; the sulfate activator is selected from at least one of natural gypsum, desulfurized gypsum, fluorstypsum and phosphogypsum.

6. The filling gelling material according to claim 1, characterized in that: Based on the mass of the filling cementitious material being 100%, the content of the blast furnace slag powder is 50-70%, and the content of the fly ash is 5-15%.

7. A method for preparing a filling gelling material, characterized in that: It includes the following steps: The blast furnace slag powder, fly ash, ultrafine tailings powder, alkaline activator and sulfate activator are mixed evenly to obtain a filling gelling material; the ultrafine tailings powder has a specific surface area of ​​600 to 800 m 2 / kg.

8. The preparation method according to claim 7, characterized in that Tailings dust collection powder, blast furnace slag powder and grinding aid are mixed to form a mixture A, and the mixture is ground to obtain the ultrafine tailings powder.

9. The preparation method according to claim 8, characterized in that The mixture A comprises, by weight percentage, 55-69% of tailings dust collection powder, 30-44% of blast furnace slag powder and 0.5-1.5% of grinding aid.

10. A slurry for filling a mine goaf, characterized in that: The mine goaf filling slurry is prepared by mixing the filling cementitious material according to any one of claims 1 to 6 and tailings slurry in a lime-sand mass ratio of 1:4 to 12.

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