A lightweight filling material, its preparation method and usage method

Abstract

The present invention relates to the field of filling, and particularly to a lightweight filling material, a preparation method thereof, and a usage method thereof. A lightweight filling material of the present invention, the raw materials for its preparation include composition A and composition B with a mass ratio of 1:1. Composition A includes the following components by mass parts: 60 - 75 parts of water, 70 - 75 parts of portland cement clinker, 15 - 22 parts of fly ash, 8 - 10 parts of sodium percarbonate; Composition B includes the following components by mass parts: 60 - 75 parts of water, 25 - 30 parts of lime, 47 - 50 parts of gypsum, 8 - 18 parts of stone powder, 10 - 12 parts of foam stabilizer. After the lightweight filling material of the present invention is filled into the position to be filled, it can be cured and formed to obtain a filling body, and the density of the filling body is 300 - 900 kg / m³, and the compressive strength is 0.23 - 25 MPa.

Description

Technical Field

[0001] The present invention relates to the field of filling, and in particular to a lightweight filling material, a preparation method thereof and a usage method thereof. Background Art

[0002] Lightweight filling materials are mainly used for filling small coal mine goaf areas. Currently, ultra-high water filling materials are mainly used for filling small goaf areas, and the construction process of this material is simple. However, when it is necessary to remove the filling material mixed in coal through coal preparation after filling, since most coal preparation plants use heavy medium coal preparation, this method requires that the density of the impurities (including the filling material) to be washed out is greater than that of coal in order to separate the coal and the impurities. The density of the crystal water filler of ultra-high water is about 1.2 t / m³, which is less than that of coal (such as anthracite), so this filling material cannot be washed out. Furthermore, due to the presence of the filling material, the coal obtained finally has relatively many impurities, affecting the usage effect of the coal.

[0003] At the same time, in the prior art, since the water-cement ratio of the ultra-high water filling material is relatively high, a large amount of crystal water is contained in the solidified filling material after solidification. When the solidified body is cut by a coal mining machine, the water is easily separated out, which is likely to cause the belt conveyor of the coal mining machine to slip and even cause the coal seam to burst. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a lightweight filling material that is easy to wash and is not likely to have crystal water separated out.

[0005] In order to achieve the technical effects of the present invention, the following technical solutions are adopted for implementation:

[0006] A lightweight filling material, the preparation raw materials of which include composition A and composition B with a mass ratio of 1:1. Composition A includes the following components by mass parts: 60 - 75 parts of water, 70 - 75 parts of portland cement clinker, 15 - 22 parts of fly ash, and 8 - 10 parts of sodium percarbonate;

[0007] Composition B includes the following components by mass parts: 60 - 75 parts of water, 25 - 30 parts of lime, 47 - 50 parts of gypsum, 8 - 18 parts of stone powder, and 10 - 12 parts of foam stabilizer;

[0008] The preparation method of the lightweight filling material includes the following steps:

[0009] (1) Grind the portland cement clinker in composition A to a specific surface area of more than 300 m² / kg, then mix it with fly ash and sodium percarbonate, and add water to obtain slurry A; mix lime, gypsum, stone powder, and foam stabilizer in composition B, and add water to make slurry B;

[0010] (2)After separately transporting slurry A and slurry B, mix slurry A and slurry B and stir evenly to obtain a material slurry (i.e., a lightweight filling material); after the material slurry is filled into the position to be filled, it can be cured and formed to obtain a filling body, and the density of the filling body is 300-900 kg / m³, and the compressive strength is 0.23-16 MPa.

[0011] As a further improvement, step (2) is to separately transport slurry A and slurry B for 50-2000 meters and then mix slurry A and slurry B.

[0012] As a further improvement, in the Portland cement clinker, the content of clinker and gypsum > 80%; in step (2), the conveying flow rate is 10 cubic meters per hour, and the inner diameter of the pipelines for conveying slurry A and slurry B is 32 mm.

[0013] As a further improvement, in the Portland cement clinker, the content of clinker and gypsum > 80%. The high content of effective components can well meet the requirements.

[0014] As a further improvement, the fly ash is grade I fly ash.

[0015] As a further improvement, the effective components of the lime and gypsum are above 90%, and the residue on a 0.08 mm fineness sieve of the lime and gypsum is < 10%. In this way, the reaction is more sufficient.

[0016] As a further improvement, the stone powder includes one or a combination of limestone powder, dolomite powder, and quartz powder.

[0017] As a further improvement, in step (1), grind the Portland cement clinker in composition A to a specific surface area of more than 300 ㎡ / kg, then mix it with fly ash and sodium percarbonate, and add water and stir for 3-5 minutes to obtain slurry A; mix the lime, gypsum, stone powder, and foam stabilizer in composition B, and add water and stir for 3-5 minutes to make slurry B.

[0018] As a further improvement, in step (2), mix slurry A and slurry B and stir for 1 minute to obtain a material slurry with a temperature of 16-25 °C.

[0019] The present invention also provides a method for using the above-mentioned lightweight filling material, and the method for using it is: fill the material slurry into the position to be filled for filling, and after the material slurry is cured and formed, a filling body is obtained; the position to be filled is the position in the underground roadway that needs to be filled; such as: underground goaf or empty roadway.

[0020] In the present invention, heat is provided by the exothermic reaction of lime with water, which promotes the reaction of sodium percarbonate with water to generate oxygen bubbles. A foam stabilizer is used in cooperation to extend the existence time of the foam. Together with stone powder, the fluidity and workability of composition B, slurry A and slurry B are increased. At the same time, the strength of the filling body can be adjusted with stone powder, and thus a filling body with a small density and a wide range of compressive strengths can be obtained.

[0021] By adding fly ash, the fluidity and workability of composition A, slurry A and slurry B are increased. All kinds of substances cooperate with each other synergistically, and thus a lightweight filling material with excellent performance can be obtained.

[0022] At the same time, in the prior art, since the on-site construction environment is complex and it is difficult to adjust production equipment (such as a grouting pump), in order to ensure the smooth progress of production, the mass ratio of composition A to composition B is adjusted to 1:1. In addition, since gypsum is easy to absorb moisture, the slurry is prone to coagulation, and thus it is not easy to cause non-coagulation due to excessive water addition, ensuring normal production.

[0023] The present invention has the following beneficial effects:

[0024] 1. The beneficial effects of the preparation method of the present invention include:

[0025] Since slurry A and slurry B are transported separately, during the transportation process, the temperature of slurry A is relatively low, and sodium percarbonate is not easy to react to generate bubbles. While during the transportation process of slurry B, lime reacts with water to release heat. When reaching the designated position, due to the relatively high temperature of slurry B, when slurry A and slurry B are mixed, the temperature of the mixture (material slurry) is relatively high, which promotes the reaction of sodium percarbonate with water to release bubbles, and thus a lightweight filling material with excellent performance can be obtained. Compared with the case where slurry A and slurry B are mixed first and then transported, the transportation distance can be greatly increased. For places with high space limitations, such as underground coal mines, due to limited space, it is very difficult to transport solid materials. By mixing solid materials with water and then sending them through pipelines, compared with the case where slurry A and slurry B coagulate first and then are transported, a large amount of transportation resources can be saved, the transportation cost can be reduced, and the energy consumption can be reduced. At the same time, transporting slurry A and slurry B first and then mixing can also reduce the density of the filling body, and when the demand for compressive strength is relatively high, it can greatly meet the production needs, producing unexpected technical effects.

[0026] 2. The beneficial effects of the filling body of the present invention include:

[0027] 2.1 Light weight. The density of the filling body of the present invention is 300 - 900 kg / m³, which is less than that of water. The filling body can be separated by water, and the lightweight filling material in the coal mine can be removed through water separation, so that there is not likely to be filling material in the coal mine, improving the purity of the coal.

[0028] 2.2. Wide range of compressive strength. The lightweight filling material prepared by the present invention has a compressive strength that can be adjusted between 0.23 - 16 MPa, with a wide compressive range. Compared with the existing ultra-high water filling material with a narrow compressive range (generally between 1.0 - 1.5 MPa), the compressive strength range is increased, and the application range is wider.

[0029] 2.3. Integrity: It can be cast in-situ according to different needs. Since the material is in a liquid state when it enters the underground roadway, the liquid will fill every space and can be closely combined with the roadway, thus also having good water resistance.

[0030] 2.4. No crystallization water will be precipitated: Due to the small water-cement ratio and small water consumption in the formula of the present invention, all water participates in the hydration reaction, and there is no crystallization water in the coagulum, so no crystallization water will be precipitated, and it will not cause the belt of the coal mining machine to slip or even cause the coal seam to burst. Compared with the existing ultra-high water filling material, its coagulum contains a large amount of crystallization water, producing unexpected technical effects.

[0031] 2.5. Environmental protection: The main raw materials used are siliceous materials and calcareous materials existing in nature, which do not contain harmful substances and have no pollution to the environment and no fire hazards.

[0032] 2.6. Economy: The comprehensive cost is low. Specific implementation manners

[0033] Example 1

[0034] A lightweight filling material, the preparation raw materials of which include composition A and composition B with a mass ratio of 1:1. Composition A includes the following components by mass parts: 60 parts of water, 70 parts of portland cement clinker, 15 parts of fly ash, and 8 parts of sodium percarbonate; Composition B includes the following components by mass parts: 60 parts of water, 25 parts of lime, 47 parts of gypsum, 11 parts of stone powder, and 10 parts of foam stabilizer.

[0035] Example 2

[0036] A lightweight filling material, the preparation raw materials of which include composition A and composition B with a mass ratio of 1:1. Composition A includes the following components by mass parts: 75 parts of water, 75 parts of portland cement clinker, 22 parts of fly ash, and 10 parts of sodium percarbonate;

[0037] Composition B includes the following components by mass parts: 75 parts of water, 30 parts of lime, 50 parts of gypsum, 18 parts of stone powder, and 12 parts of foam stabilizer.

[0038] Example 3

[0039] A lightweight filling material, the raw materials for its preparation are composition A and composition B with a mass ratio of 1:1. Composition A includes the following components by mass parts: 75 parts of water, 75 parts of Portland cement clinker, 15 parts of fly ash, and 10 parts of sodium percarbonate; Composition B includes the following components by mass parts: 75 parts of water, 30 parts of lime, 50 parts of gypsum, 8 parts of stone powder, and 12 parts of foam stabilizer.

[0040] Example 4

[0041] A lightweight filling material, the raw materials for its preparation include composition A and composition B with a mass ratio of 1:1. Composition A includes the following components by mass parts: 60 parts of water, 70 parts of Portland cement clinker, 22 parts of fly ash, and 8 parts of sodium percarbonate; Composition B includes the following components by mass parts: 60 parts of water, 25 parts of lime, 47 parts of gypsum, 18 parts of stone powder, and 10 parts of foam stabilizer.

[0042] Comparative Example 1.1

[0043] The raw materials are the same as those in Example 1, with the only difference being that composition B does not add stone powder, the mass of other components in composition B increases by 11 parts, and the mass ratio of the increased other components in composition B is water:lime:gypsum:foam stabilizer = 60:25:47:10.

[0044] Comparative Example 1.2

[0045] The raw materials are the same as those in Example 1, with the only difference being that composition B does not add foam stabilizer, the mass of other components in composition B increases by 10 parts, and the mass ratio of the increased other components in composition B is water:lime:gypsum:stone powder = 60:25:47:11.

[0046] Comparative Example 1.3

[0047] The raw materials are the same as those in Example 1, with the only difference being that composition A does not add sodium percarbonate, the mass of other components in composition A increases by 8 parts, and the mass ratio of the increased other components in composition A is water:Portland cement clinker:fly ash = 60:70:15.

[0048] Comparative Example 1.4

[0049] The raw materials are the same as those in Example 1, with the only difference being that composition B does not add lime, the mass of other components in composition B increases by 25 parts, and the mass ratio of the increased other components in composition B is water:gypsum:stone powder:foam stabilizer = 60:47:11:10.

[0050] Comparative Example 1.5

[0051] The preparation raw materials are the same as those in Example 1. The difference in the preparation method from Example 1 is only that: in step (2) of the preparation method, it is not necessary to separately transport slurry A and slurry B for 1000 meters. Instead, slurry A and slurry B are directly mixed and then transported for 1000 meters; other preparation methods are the same as those in Example 1.

[0052] Comparative Example 1.6

[0053] The preparation raw materials are the same as those in Example 1. The difference in the preparation method from Example 1 is only that: in step (2) of the preparation method, after separately transporting slurry A and slurry B for 50 meters, slurry A and slurry B are mixed; other preparation methods are the same as those in Example 1.

[0054] Comparative Example 3.1

[0055] The preparation raw materials are the same as those in Example 3. The difference is only that: no stone powder is added to Composition B, the mass of other components in Composition B increases by 8 parts, and the mass ratio of the other components increased in Composition B is water:lime:gypsum:foam stabilizer = 75:30:50:12.

[0056] Comparative Example 3.2

[0057] The preparation raw materials are the same as those in Example 3. The difference is only that: no foam stabilizer is added to Composition B, the mass of other components in Composition B increases by 12 parts, and the mass ratio of the other components increased in Composition B is water:lime:gypsum:stone powder = 75:30:50:8.

[0058] Comparative Example 3.3

[0059] The preparation raw materials are the same as those in Example 3. The difference is only that: no sodium percarbonate is added to Composition A, the mass of other components in Composition A increases by 10 parts, and the mass ratio of the other components increased in Composition A is water:portland cement clinker:fly ash = 75:75:15.

[0060] Comparative Example 3.4

[0061] The preparation raw materials are the same as those in Example 3. The difference is only that: no lime is added to Composition B, the mass of other components in Composition B increases by 30 parts, and the mass ratio of the other components increased in Composition B is water:gypsum:stone powder:foam stabilizer = 75:50:8:12.

[0062] Comparative Example 3.5

[0063] The preparation raw materials are the same as those in Example 3. The difference in the preparation method from Example 3 is only that: in step (2) of the preparation method, it is not necessary to separately transport slurry A and slurry B for 1000 meters. Instead, slurry A and slurry B are directly mixed and then transported for 1000 meters; other preparation methods are the same as those in Example 3.

[0064] Comparative Example 4.1

[0065] The preparation raw materials are the same as those in Example 4, with the only difference being that: stone powder is not added to Composition B, the mass of other components in Composition B increases by 18 parts, and the mass ratio of the other components added in Composition B is water:lime:gypsum:foam stabilizer = 60:25:47:10.

[0066] Comparative Example 4.2

[0067] The preparation raw materials are the same as those in Example 4, with the only difference being that: the foam stabilizer is not added to Composition B, the mass of other components in Composition B increases by 10 parts, and the mass ratio of the other components added in Composition B is water:lime:gypsum:stone powder = 60:25:47:18.

[0068] Comparative Example 4.3

[0069] The preparation raw materials are the same as those in Example 4, with the only difference being that: sodium percarbonate is not added to Composition A, the mass of other components in Composition A increases by 8 parts, and the mass ratio of the other components added in Composition A is water:portland cement clinker:fly ash = 60:70:22.

[0070] Comparative Example 4.4

[0071] The preparation raw materials are the same as those in Example 4, with the only difference being that: lime is not added to Composition B, the mass of other components in Composition B increases by 25 parts, and the mass ratio of the other components added in Composition B is water:gypsum:stone powder:foam stabilizer = 60: 47:18:10.

[0072] Comparative Example 4.5

[0073] The preparation raw materials are the same as those in Example 4, and the difference in the preparation method from Example 4 is only that: in step (2) of the preparation method, it is not necessary to separately transport slurry A and slurry B for 1000 meters. Instead, slurry A and slurry B are directly mixed and then transported for 1000 meters; other preparation methods are the same as those in Example 1.

[0074] In each of the examples and comparative examples, the raw materials used can be: in the portland cement clinker, the content of clinker and gypsum > 80%; the fly ash is class I fly ash; the effective components of the lime and gypsum are both above 90%, and the residue on a 0.08 mm sieve of the lime and gypsum < 10%; the stone powder is limestone powder; the stone powder can also be one or a combination of limestone powder, dolomite powder, and quartz powder. The foam stabilizer model is AE - 1450; it can be purchased from Nanjing Xinyi Synthetic Technology Co., Ltd.; brand: Xinyi Synthetic; model AE - 1450; the trade name is also called powder air-entraining agent.

[0075] Preparation Method

[0076] The preparation methods of the filling materials in Examples 1, 2, 3, 4, 1.1 - 1.4, 3.1 - 3.4, and 4.1 - 4.4 include the following steps:

[0077] (1) Grind the portland cement clinker in Composition A to a specific surface area of more than 300 ㎡ / kg, then mix it with fly ash and sodium percarbonate, and add water and stir for 3 - 5 minutes to obtain Slurry A; mix the lime, gypsum, stone powder, and foam stabilizer in Composition B, add water and stir for 3 - 5 minutes to make Slurry B.

[0078] (2) After transporting Slurry A and Slurry B separately for 1000 meters, mix Slurry A and Slurry B, stir evenly, and the stirring time is 1 minute to obtain a material slurry with a temperature of 16 - 25 °C; Slurry A and Slurry B can be transported by a double - liquid grouting pump (transport driving force), the transport distance is 1000 meters, the rated transport flow of the double - liquid grouting pump is 10 cubic meters per hour, and the inner diameters of the pipelines (or pipes) for transporting Slurry A and Slurry B are both 32 millimeters. The power of the double - liquid grouting pump is 22 thousand KW. The transport speeds of Slurry A and Slurry B can be the same, and they reach the designated position simultaneously.

[0079] The inner diameter of the pipeline can also be selected from 25 - 51 mm. Only with an inner diameter of 32 mm, it is not easy to block the pipeline after a long time of use, nor will there be a situation where the pipeline is blocked due to the pipeline being too thick after a long time of use.

[0080] The usage methods of the filling materials in Examples 1, 2, 3, 1.1 - 1.6, 3.1 - 3.5, and 4.1 - 4.5 include the following steps:

[0081] The usage method is as follows: Fill the material slurry into the position to be filled for filling. After the material slurry solidifies and forms, a filler is obtained; the position to be filled is the position in the underground roadway that needs to be filled. The curing time is 35 - 40 minutes.

[0082] For the convenience of testing, pour (fill) the material slurry into a mold placed in the underground roadway, and it solidifies and forms in 40 minutes to make a material test block (which is also a filler) for testing.

[0083] Effect test

[0084] Test method:

[0085] 1. The method used for density testing is the density test method in JGJ / T 70 - 2009 "Standard Test Methods for Basic Properties of Building Mortars".

[0086] 2. The test method used for compressive strength testing is the cube compressive strength test method in JGJ / T 70 - 2009 "Standard Test Methods for Basic Properties of Building Mortars".

[0087] The test results are shown in Table 1.

[0088] Table 1

[0089] Example Density (kg / m³) Uniaxial compressive strength (MPa) Example 1 578 5.1 Example 2 425 1.6 Example 3 300 0.23 Example 4 900 16.0 Comparative example 1.1 578 3.5 Comparative example 1.2 868 7.9 Comparative example 1.3 1736 19.1 Comparative example 1.4 1446 12.9 Comparative example 1.5 754 6.7 Comparative example 1.6 578 5.1 Comparative example 3.1 300 0.1 Comparative example 3.2 500 1.0 Comparative example 3.3 1666 18.0 Comparative example 3.4 1400 12.0 Comparative example 3.5 700 7.0 Comparative example 4.1 900 8.0 Comparative example 4.2 1500 23.0 Comparative example 4.3 1777 25.0 Comparative example 4.4 1480 13.4 Comparative example 4.5 1110 17.1 Ultra-high water filling material purchased on the market 1160 1.1

[0090] As can be seen from Table 1, the light filling material of the present invention has a low density and a wide compressive strength range, and can be well washed by water (the light filling material in coal can be removed by water washing to improve the purity of coal and meet the usage requirements), and has good application effects.

[0091] By separately transporting Composition A and Composition B, not only are the raw materials for preparation good, but also the transportation distance is long.

[0092] By mixing sodium percarbonate, foam stabilizer, stone powder, etc., the density and compressive strength of the obtained filling body can both meet the requirements, and unexpected technical effects are produced.

[0093] Each component of the present invention synergizes and cooperates with each other. Removing any one component may result in the inability to meet the requirements of the usage effect.

[0094] At the same time, it was found in the experiment that when the raw materials for preparation, the preparation method, and the usage method of Examples 1-4 remained unchanged and the transportation distance was 2000 meters, the density and compressive strength of the obtained filling body were basically the same as those when the transportation distance was 1000 meters.

[0095] In the present invention, the lime is quicklime.

[0096] The parts in the present invention are parts by mass, for example, it can be kg.

[0097] The above are only the preferred embodiments of the present invention, and the scope of implementation of the present invention cannot be limited thereby. That is, all simple equivalent changes and modifications made according to the content recorded in the claims of the present invention and the invention specification still fall within the scope covered by the claims of the present invention. In addition, the abstract part and the title are only used to assist in searching for patent documents and are not used to limit the scope of rights of the present invention.

Claims

1. A lightweight filling material, characterized in that, The raw materials for its preparation include composition A and composition B with a mass ratio of 1:

1. Composition A includes the following components by mass parts: 75 parts of water, 75 parts of Portland cement clinker, 15 - 22 parts of fly ash, and 10 parts of sodium percarbonate; Composition B consists of the following components by mass parts: 75 parts of water, 30 parts of lime, 50 parts of gypsum, 8 - 18 parts of stone powder, and 12 parts of foam stabilizer; The preparation method of the lightweight filling material includes the following steps: (1) Grind the Portland cement clinker in composition A to a specific surface area of more than 300 ㎡ / kg, then mix it with fly ash and sodium percarbonate, and add water to obtain slurry A; Mix lime, gypsum, stone powder, and foam stabilizer in composition B, and add water to make slurry B; (2) After transporting slurry A and slurry B respectively, mix slurry A and slurry B and stir evenly to obtain the material slurry; After the material slurry is filled into the position to be filled, it can solidify and form a filling body. The density of the filling body is 300 - 425 kg / m³, and the compressive strength is 0.23 - 1.6 MPa; Step (2) is to transport slurry A and slurry B for 50 - 2000 meters respectively, then mix slurry A and slurry B to obtain a material slurry with a temperature of 16 - 25℃; The transport flow rate in step (2) is 10 cubic meters per hour, and the inner diameters of the pipelines for transporting slurry A and slurry B are both 32 millimeters.

2. The lightweight filling material according to claim 1, wherein In the Portland cement clinker, the content of clinker and gypsum > 80%.

3. A lightweight filling material according to claim 1, characterized in that, The fly ash is grade I fly ash.

4. A lightweight filling material according to claim 1, characterized in that, The effective components of the lime and gypsum are both above 90%, and the residue on a 0.08 - millimeter fineness sieve of the lime and gypsum < 10%.

5. A lightweight filling material according to claim 1, characterized in that The stone powder includes one or a combination of limestone powder, dolomite powder, and quartz powder.

6. The preparation method of a lightweight filling material according to claim 1, characterized in that, In step (1), grind the Portland cement clinker in composition A to a specific surface area of more than 300 ㎡ / kg, then mix it with fly ash and sodium percarbonate, and stir with water for 3 - 5 minutes to obtain slurry A; Mix lime, gypsum, stone powder, and foam stabilizer in composition B, and stir with water for 3 - 5 minutes to make slurry B.

7. The preparation method of a lightweight filling material according to claim 6, characterized in that, In step (2), mix slurry A and slurry B and stir for 1 minute to obtain a material slurry with a temperature of 16 - 25℃.

8. The preparation method of a lightweight filling material according to claim 6, characterized in that, The foam stabilizer model is AE - 1450.

9. The method of using a lightweight filling material according to any one of claims 1-5, characterized in that, Its usage method is: Fill the material slurry into the position to be filled for filling. After the material slurry solidifies and forms, a filling body is obtained; The position to be filled is the position in the underground roadway that needs to be filled.