A method for determining a coal-based solid waste disposal rate of an underground filling working face

Abstract

This invention discloses a method for determining the coal-based solid waste disposal rate in underground backfilling faces. The coal-based solid waste disposal rate is the ratio of the amount of coal-based solid waste disposed of in the backfilling faces to the total amount of coal-based solid waste in the mine. The determination steps are as follows: First, the total amount of coal-based solid waste Q in the mine is calculated; then, based on the proportion of backfilling materials used in the mine, the proportion of coal-based solid waste in the backfilling materials is determined; the layout of each backfilling face in the mine is determined, and the backfilling space volume V is calculated; the weak dynamic force P and the number of actions x of the backfilling support on the backfill body are determined, and a weak dynamic compaction test of the backfilling material is conducted to determine the bulk density ρ of the backfilling material after the weak dynamic action; finally, the total amount of coal-based solid waste Q disposed of in each backfilling face in the mine is calculated. c Finally, the coal-based solid waste disposal rate η is calculated. This invention quantitatively determines the coal-based solid waste disposal effect in the backfilling face through the coal-based solid waste disposal rate, and the results can provide a basis for the design of mine backfilling systems and the evaluation of backfilling effects.

Description

Technical Field

[0001] This invention relates to backfilling mining technology, and in particular to a method for determining the coal-based solid waste disposal rate in solid backfilling mining. Background Technology

[0002] Coal mining generates a large amount of coal-based solid waste, such as gangue, fly ash, and coal slime, while extracting coal resources. The generation of these solid wastes seriously pollutes the surface ecological environment and occupies a large amount of ground space. How to efficiently dispose of coal-based solid waste has become a research hotspot.

[0003] Solid backfilling mining technology, as one of the important technical means of green mining system, mixes coal-based solid waste such as gangue, fly ash, and coal slime, as well as non-coal-based solid waste such as aeolian sand, loess lime, etc., in a certain proportion to make backfill material. It is transported to the underground goaf area for backfilling through feeding wells, belt conveyors, etc. The backfill material can be subjected to weak force through backfilling hydraulic supports to improve the backfilling effect. Solid backfilling mining can efficiently dispose of a large amount of solid waste while relieving coal pressure in the "three underground" areas, realizing water-conserving mining, reducing surface deformation, and effectively protecting the surface ecological environment.

[0004] However, due to various factors such as coal-based solid waste production, backfill face size, backfill material performance requirements, backfill cost, and backfill speed, most mines cannot achieve complete backfill disposal of coal-based solid waste and can only achieve partial disposal. If the coal-based solid waste disposal rate of the underground backfill face can be determined, the coal-based solid waste disposal capacity and disposal effect of solid backfill mines can be predicted and evaluated.

[0005] Therefore, researching a method for determining the disposal rate of coal-based solid waste in underground filling working faces is crucial for accurately grasping the disposal capacity and effectiveness of coal-based solid waste in mines. Summary of the Invention

[0006] The purpose of this invention is to address the above-mentioned technical problems by providing a simple, fast, and reliable method for determining the disposal rate of coal-based solid waste in underground filling working faces, so as to accurately grasp the disposal capacity and effect of coal-based solid waste in mines.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0008] The purpose of this invention is to provide a method for determining the coal-based solid waste disposal rate in underground backfilling working faces. The coal-based solid waste disposal rate is the ratio of the amount of coal-based solid waste disposed of in the mine backfilling working face to the total amount of coal-based solid waste in the mine. The method for determining this rate is as follows:

[0009] a. Calculate the total amount of coal-based solid waste Q in the mine;

[0010] b. Determine the proportion e of coal-based solid waste in the backfill material based on the proportion of the backfill material used in the mine;

[0011] c. Determine the layout of each filling working face in the well and calculate the filling space volume V;

[0012] d. Determine the unit weight ρ of the filling material after weak dynamic action;

[0013] e. Calculate the total amount of coal-based solid waste Q disposed of at each backfilling face in the mine. c :

[0014] Q c =ρVe (1)

[0015] In the formula, Q c ρ represents the total amount of coal-based solid waste disposed of in each backfilling face of the mine; ρ is the bulk density of the backfill material after weak dynamic action; V is the volume of the backfill space; e is the proportion of coal-based solid waste in the backfill material.

[0016] f. Calculate the coal-based solid waste disposal rate η:

[0017]

[0018] In the formula, η is the coal-based solid waste disposal rate; Q c Q represents the total amount of coal-based solid waste disposed of at each backfilling working face of the mine; Q is the amount of coal-based solid waste in the mine.

[0019] Optionally, in one embodiment of this application, the coal-based solid waste includes gangue, fly ash, and coal slime, etc. This application is applicable to all application scenarios of coal-based solid waste and is not limited to specific coal-based solid waste components. Further details are omitted here, but all raw materials involving coal-based solid waste fall within the protection scope of this application.

[0020] Optionally, in one embodiment of this application, step b, the method for determining the proportion e of coal-based solid waste in the backfill material, includes:

[0021]

[0022] In the formula, e represents the proportion of coal-based solid waste in the filling material; q c q represents the amount of coal-based solid waste in the backfill material. t This refers to the amount of other materials added to the filling material besides coal-based solid waste.

[0023] Optionally, in one embodiment of this application, step c, the method for calculating the filling space volume V, includes:

[0024]

[0025] In the formula, V is the volume of the filling space; n is the number of filling working surfaces; h i The mining height is set for the i-th working face; l i L is the length of the i-th working surface; iLet be the advancing length of the i-th working face.

[0026] Optionally, in one embodiment of this application, in step d, the determination of the bulk density ρ of the filling material after weak dynamic action is obtained by a weak dynamic compaction test device for filling materials. The device includes a base plate and a hydraulic cylinder and a filling material box fixed on the base plate.

[0027] A hydraulic cylinder fixing plate is fixed to one end of the base plate, and a filling material box is fixed to the other end. The filling material box has an opening on the side facing the hydraulic cylinder fixing plate, and filling material is placed in the filling material box.

[0028] The bottom of the cylinder is fixed to the cylinder fixing plate, and the cylinder head is fixed to a vertical pressure plate. The pressure plate extends into the opening of the filling material box. The cylinder drives the pressure plate to move along the cylinder axis in the filling material box to compact the filling material.

[0029] In this application, the method for conducting a weak dynamic compaction test of the filling material using the device described above is as follows: after compacting the filling material with weak force P x ​​times, the bulk density ρ of the filling material after weak dynamic action is measured. Specifically, this includes: placing the filling material in the filling material box, compacting the filling material with weak force P as the cylinder pressure x times, after which the filling material becomes a cuboid under weak dynamic action, and reading the length l of the compacted body of the filling material after weak dynamic action. x Calculate the volume of the compacted filling material, and further obtain the unit weight ρ of the filling material under weak dynamic action. The calculation formula is as follows:

[0030]

[0031] In the formula, ρ is the unit weight of the filling material after weak dynamic action, t / m³. 3 m represents the mass of the filling material, in tons; l x s is the length of the compacted filling material after weak dynamic action, in meters; s is the internal width of the filling material box, in meters; h is the internal height of the filling material box, in meters.

[0032] Optionally, in one embodiment of this application, the side plate of the filling material box is a transparent acrylic plate, and a scale is provided along the axial direction of the hydraulic cylinder for reading the length l of the compacted core of the internal filling material. x .

[0033] Optionally, in one embodiment of this application, the weak power P provided by the hydraulic cylinder is 1 to 3 MPa.

[0034] Optionally, in one embodiment of this application, a cylinder support plate is fixed on the base plate to support the cylinder barrel of the cylinder.

[0035] Optionally, in one embodiment of this application, a reinforcing steel plate is provided on the outer side of the cylinder fixing plate to stabilize the cylinder fixing plate.

[0036] Optionally, in one embodiment of this application, fastening bolts and corner reinforcing ribs are provided between adjacent side plates of the filling material box to reinforce the filling material box.

[0037] Beneficial Effects: One of the primary purposes of backfilling mining is the disposal of coal-based solid waste such as gangue. The disposal rate of coal-based solid waste is a crucial parameter for designing mine backfilling systems and an important indicator for evaluating the effectiveness of mine backfilling. This invention can accurately determine the coal-based solid waste disposal rate of underground backfilling faces based on the proportion of backfilling materials used in the mine, the layout of backfilling working faces, and weak dynamic compaction tests of backfilling materials. This rate is the ratio of the amount of coal-based solid waste disposed of at the mine backfilling working face to the total amount of coal-based solid waste in the mine, thus providing a basis for mine backfilling system design and backfilling effectiveness evaluation. This method is simple to implement, has a wide range of applications, and is highly practical. Attached Figure Description

[0038] Figure 1 A step-by-step diagram illustrating the method for determining the disposal rate of coal-based solid waste in underground backfilling working faces;

[0039] Figure 2 Front view of the equipment used for weak dynamic compaction testing of filling materials.

[0040] Wherein: 1-base plate, 2-reinforcing steel plate, 3-cylinder fixing plate, 4-cylinder, 5-cylinder support plate, 6-pressure plate, 7-upper side plate, 8-right side plate, 9-rear side plate, 10-corner reinforcing rib, 11-fastening bolt, 12-scale; 13-scale corresponding to the length of filling material after weak dynamic action, 14-filling material after weak dynamic action, 15-left side plate.

[0041] Figure 3 Top view of the equipment used for weak dynamic compaction testing of filling materials. Detailed Implementation

[0042] The coal-based solid waste disposal rate is the ratio of the amount of coal-based solid waste disposed of in the mine backfilling face to the total amount of coal-based solid waste in the mine. The method for determining the coal-based solid waste disposal rate in underground backfilling faces provided in this embodiment of the invention is as follows: Figure 1 As shown, the method for determining it includes the following steps:

[0043] a. Calculate the total amount of coal-based solid waste Q in the mine;

[0044] b. Determine the proportion e of coal-based solid waste in the backfill material based on the mix ratio of the backfill material used in the mine. In this embodiment of the application, as an example, the calculation method is as follows:

[0045]

[0046] In the formula, e represents the proportion of coal-based solid waste in the filling material; q c q represents the amount of coal-based solid waste in the backfill material. t This refers to the amount of other materials added to the filling material besides coal-based solid waste;

[0047] c. Determine the layout of each filling working face downhole and calculate the filling space volume V. In this embodiment of the application, as an example, the calculation method is as follows:

[0048]

[0049] In the formula, V is the volume of the filling space; n is the number of filling working surfaces; h i The mining height is set for the i-th working face; l i L is the length of the i-th working surface; i Let be the advancing length of the i-th working face;

[0050] d. Determine the unit weight ρ of the filling material after weak dynamic action;

[0051] e. Calculate the total amount of coal-based solid waste disposed of at each backfilling face in the mine.

[0052] In the formula, Q c ρ represents the total amount of coal-based solid waste disposed of in each backfilling face of the mine; ρ is the bulk density of the backfill material after weak dynamic action; V is the volume of the backfill space; e is the proportion of coal-based solid waste in the backfill material.

[0053] f. Calculate the coal-based solid waste disposal rate η

[0054]

[0055] In the formula, η is the coal-based solid waste disposal rate; Q c Q represents the total amount of coal-based solid waste disposed of at each backfilling working face of the mine; Q is the amount of coal-based solid waste in the mine.

[0056] In one example, the coal-based solid waste includes gangue, fly ash, and coal slime, etc.; the non-coal-based solid waste may include aeolian sand, loess, lime, etc.

[0057] In one example, the weak dynamic compaction test of the filling material refers to simulating the weak dynamic action of the downhole filling support on the filling body. The filling material is compacted x times with a weak force P in a dedicated weak dynamic compaction test device, and its unit weight ρ is then measured. The dedicated test device for conducting the weak dynamic compaction test of the filling material is, for example... Figure 2 As shown, it mainly consists of a base plate 1, an oil cylinder 4 fixed on the base plate 1, and a filling material box. The side plate of the filling material box is a transparent acrylic plate, and there are scales printed on the left and right side plates. The oil cylinder 4 can adjust the pressure.

[0058] The specific structure of the device used in this application for conducting a weak dynamic compaction test of filling material includes: a cylinder fixing plate 3 is fixed to one end of the base plate 1, and the filling material box is fixed to the other end. The filling material box has an opening on one side facing the cylinder fixing plate 3, and filling material is placed in the filling material box; the bottom of the cylinder 4 is fixed to the cylinder fixing plate 3, and a vertical pressure plate 6 is fixed to the cylinder head of the cylinder 4. The pressure plate 6 extends into the opening of the filling material box, and the cylinder 4 drives the pressure plate 6 to move along the axial direction of the cylinder 4 in the filling material box to compact the filling material.

[0059] In one example, the side panels of the filling material box (such as...) Figure 2 , Figure 3 The upper side plate 7, right side plate 8, rear side plate 9, and left side plate 15 of the cylinder 4 are made of transparent acrylic sheets, and scales 12 are provided on both the left and right side plates along the axial direction of the cylinder 4 for reading the length l of the compacted core of the internal filling material. x .

[0060] In one example, the hydraulic cylinder provides a weak power P of 1 to 3 MPa.

[0061] In one example, a cylinder support plate 5 is fixed on the base plate 1 to support the cylinder barrel of the cylinder 4.

[0062] In one example, the cylinder fixing plate 3 is provided with a reinforcing steel plate 2 on the outside to stabilize the cylinder fixing plate 3.

[0063] In one example, fastening bolts 11 and corner reinforcing ribs 10 are provided between adjacent side plates of the filling material box to reinforce the filling material box.

[0064] The specific steps for using this device to conduct weak dynamic compaction tests on filling materials are as follows:

[0065] i. Weigh an appropriate amount of filling material and place it in the filling material box of the special experimental apparatus;

[0066] ii. Set the hydraulic cylinder pressure to a low-power P and compact the filling material x times;

[0067] iii. The filling material in the experimental device is transformed into a cuboid under weak dynamic action. The length of the filling material after weak dynamic action on the experimental device is read from the corresponding scale 13.

[0068] iv. Calculate the volume of the compacted backfill material, i.e., the backfill material 14 after weak dynamic action, and further calculate the unit weight ρ of the backfill material after weak dynamic action. The calculation formula is as follows:

[0069]

[0070] In the formula, ρ is the unit weight of the filling material after weak dynamic action, t / m³. 3 m represents the mass of the filling material, in tons; l x s is the length of the compacted filling material after weak dynamic action, in meters; s is the internal width of the filling material box, in meters; h is the internal height of the filling material box, in meters.

[0071] In one example, the weak dynamic force of the filling stent is typically 1–3 MPa.

[0072] Example

[0073] The invention will be further described below with reference to a specific mine example:

[0074] A certain mine has approximately 500,000 tons of gangue from its existing gangue pile, occupying a large amount of surface space and severely polluting the environment. To address the gangue and other coal-based solid waste, the mine plans to implement solid backfill mining, mixing gangue, coal slime, and sand in a 6:2:2 ratio and backfilling them into the goaf, then compacting the mixture using hydraulic backfill supports. The mine has a production capacity of 1 million tons per year, with remaining recoverable reserves of approximately 18 million tons. The gangue content of the coal seam is approximately 8%, and the coal slime production accounts for approximately 4% of the raw coal yield. The calculation process for its coal-based solid waste disposal rate is as follows:

[0075] a. Calculate the total amount of coal-based solid waste Q in the mine.

[0076] The coal-based solid waste of this mine mainly consists of gangue and coal slime. The total amount of gangue is approximately 1.94 million tons, which is the sum of the gangue from the mine's existing gangue mountain (500,000 tons) and the total amount of gangue in the recoverable resource reserves (the gangue content in the coal seam is approximately 8%, so it is 1.44 million tons). The coal slime content is approximately 720,000 tons (coal slime production accounts for approximately 4% of the raw coal). Therefore, the total amount of coal-based solid waste, Q, is approximately 2.66 million tons.

[0077] b. Determine the proportion of coal-based solid waste in the filling material based on the ratio of the filling material used in the mine.

[0078] The backfill material used in this mine has a ratio of gangue:coal slime:sand = 6:2:2, in which coal-based solid waste accounts for 80%.

[0079]

[0080] According to formula (Ⅰ), the proportion of coal-based solid waste is calculated to be (6+2) / 10 = 80%;

[0081] c. Determine the layout of each filling working face in the well and calculate the filling space volume V according to formula (II).

[0082] The mine plans to set up four backfilling working faces. The parameters and backfilling space of each working face are shown in Table 1.

[0083]

[0084] In the formula, V is the volume of the filling space; n is the number of filling working faces, and in this mine, n = 4; h i The mining height is set for the i-th working face; l i L is the length of the i-th working surface; i Let be the advancing length of the i-th working face;

[0085] Table 1 Working Face Parameters

[0086]

[0087] d. The weak dynamic force P of the filling support in this mine is 2.2 MPa, and the number of times it is applied is 8. Based on this, a weak dynamic compaction test of the filling material is carried out.

[0088] like Figure 2 As shown, 10 kg of filling material was placed in the filling material box of the experimental apparatus and compacted 8 times at 2.2 MPa. The length of the filling material after weak dynamic action was read from the scale 13 on the transparent acrylic plate, which is the length l of the compacted filling material after weak dynamic action. x If the density is 16.6 cm, then the bulk density ρ of the filling material after weak dynamic action can be calculated using equation (V) to be 1.50 t / m³. 3 :

[0089]

[0090] In the formula, ρ is the unit weight of the filling material after weak dynamic action, t / m³. 3 m represents the mass of the filling material, in tons; l x s is the length of the compacted filling material after weak dynamic action, in meters; s is the internal width of the filling material box, in this embodiment, s = 0.2m; h is the internal height of the filling material box, in this embodiment, h = 0.2m.

[0091] e. According to formula (Ⅲ), the total amount of coal-based solid waste disposed of in each backfilling face of the mine is 2,256,000 t:

[0092] Q c =ρVe (Ⅲ)

[0093] In the formula, Q c ρ represents the total amount of coal-based solid waste disposed of in each backfilling face of the mine; ρ is the bulk density of the backfill material after weak dynamic action, 1.50 t / m³. 3 V represents the volume of the filling space, which is 1,880,000 m³. 3 e indicates that coal-based solid waste accounts for 80% of the filling material;

[0094] f. According to formula (Ⅳ), the coal-based solid waste disposal rate η is calculated to be 84.8%.

[0095]

[0096] In the formula, η is the coal-based solid waste disposal rate; Q c Q represents the total amount of coal-based solid waste disposed of at each filling working face of the mine, 2,256,000 tons; Q represents the amount of coal-based solid waste in the mine, 2,660,000 tons.

[0097] The actual amount of coal-based solid waste disposed of in the mine was approximately 2,203,000 tons, measured using methods such as belt scales. However, due to a decrease in the gangue content of coal seams in some areas, the actual amount of coal-based solid waste produced by the mine decreased to 2,598,000 tons. Therefore, the actual coal-based solid waste disposal rate of the mine was 82.9%, and the error between the theoretical value (84.8%) and the actual value was less than 2%.

[0098] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for determining the disposal rate of coal-based solid waste in underground backfilling working faces, characterized in that, The coal-based solid waste disposal rate is the ratio of the amount of coal-based solid waste disposed of at the mine backfilling face to the total amount of coal-based solid waste in the mine. The method for determining this rate is as follows: (a). Statistically mine the total amount of coal-based solid waste Q ; (b) Determine the proportion of coal-based solid waste in the backfill material based on the proportion of the backfill material used in the mine. e ; (c) Determine the layout of each filling working face downhole and calculate the volume of the filling space. V ; (d) Determine the bulk density ρ of the filling material after weak dynamic action; With weak power P Compacted filling material x The bulk density ρ of the filling material after weak dynamic action was subsequently measured, specifically including: placing the filling material in a filling material box, and applying weak dynamic action. P For hydraulic cylinder pressure compaction filling material x After this, the filling material transforms into a cuboid under weak dynamic action, and the length of the compacted filling material after weak dynamic action is read. l x Calculate the volume of the compacted filling material, and further obtain the unit weight ρ of the filling material under weak dynamic action. The calculation formula is as follows: (5) In the formula, ρ is the unit weight of the filling material after weak dynamic action, t / m³. 3 ; m For the mass of the filling material, t; l x The length of the compacted filling material after weak dynamic action, in meters; s The internal width of the filling material box is in meters (m). h The internal height of the filling material box is in meters (m). (e) Calculate the total amount of coal-based solid waste disposed of at each backfilling face of the mine. Q c : (1) In the formula, Q c ρ represents the total amount of coal-based solid waste disposed of at each backfilling face in the mine; ρ is the bulk density of the backfill material after weak dynamic action. V To fill the space volume; e The percentage of coal-based solid waste in the filling material; (f). Calculate the coal-based solid waste disposal rate η: (2) In the formula, η is the coal-based solid waste disposal rate; Q c The total amount of coal-based solid waste disposed of in each backfilling working face of the mine; Q This refers to the amount of coal-based solid waste from the mine.

2. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 1, characterized in that, The coal-based solid waste includes gangue, fly ash, and coal slime.

3. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 1, characterized in that, In step (b), the determination of the proportion of coal-based solid waste in the backfill material is... e The methods include: (3) In the formula, e The percentage of coal-based solid waste in the filling material; q c This refers to the amount of coal-based solid waste in the filling material; q t This refers to the amount of other materials added to the filling material besides coal-based solid waste.

4. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 1, characterized in that, In step (c), the calculation of the filling space volume V The methods include: (4) In the formula, V To fill the space volume; n The number of working faces to be filled; h i For the first i Each working face is at a high elevation; l i For the first i The length of each working face; L i For the first i The working face advance length.

5. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 1, characterized in that, In step (d), the density ρ of the filling material after weak dynamic action is determined by the weak dynamic compaction test device of the filling material. The device includes a base plate (1) and a hydraulic cylinder (4) fixed on the base plate (1) and a filling material box. One end of the base plate (1) is fixed with a cylinder fixing plate (3), and the other end is fixed with a filling material box. The filling material box has an opening facing the cylinder fixing plate (3), and filling material is placed in the filling material box. The bottom of the cylinder (4) is fixed on the cylinder fixing plate (3), and the cylinder head of the cylinder (4) is fixed with a vertical pressure plate (6). The pressure plate (6) extends into the opening of the filling material box. The cylinder (4) drives the pressure plate (6) to move along the axial direction of the cylinder (4) in the filling material box to compact the filling material.

6. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 5, characterized in that, The side panel of the filling material box is made of transparent acrylic sheet, and a scale is provided along the axial direction of the oil cylinder (4) for reading the length of the compacted core of the filling material inside. l x .

7. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 5, characterized in that, The weak power provided by the hydraulic cylinder P The pressure is 1~3 MPa.

8. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 5, characterized in that, A cylinder support plate (5) is fixed on the base plate (1) to support the cylinder barrel of the cylinder (4).

9. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 5, characterized in that, The cylinder fixing plate (3) is provided with a reinforcing steel plate (2) on the outside to stabilize the cylinder fixing plate (3).

10. The method for determining the disposal rate of coal-based solid waste in underground backfilling working faces according to claim 5, characterized in that, The side plates of the filling material box are provided with fastening bolts (11) and corner reinforcing ribs (10) to reinforce the filling material box.

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