A multi-round regional coal caving method for thick coal seams

Abstract

The present invention provides a multi-round regional coal caving method for thick coal seams. Based on the geological conditions and relevant parameters of the fully-mechanized caving working face, the number of coal caving openings is obtained through reasonable calculation, and the number of coal caving groups of the working face is determined. The first-level, second-level and third-level coal caving openings are determined in sequence according to the advancing direction of the working face; coal is cavitated at the first group of first-level coal caving openings first, then at a group of second-level coal caving openings, and finally at a group of third-level coal caving openings. After multiple rounds of coal caving in each group, it is ensured that the top coal is fully recovered, thereby achieving an improvement in the top coal recovery rate of the working face.

Description

Technical Field

[0001] The invention relates to the technical field of coal caving, and in particular to a multi-round regional coal caving method for thick coal seams. Background Art

[0002] The fully mechanized top coal caving technology has gradually become the main technology for mining thick coal seams in my country, forming a fully mechanized top coal caving mining process mode for various conditions. It is widely used in thick and extra-thick coal seam mining due to its strong applicability, low cost and high efficiency. However, due to the randomness in the caving process, the top coal migration and caving rules show different characteristics for different coal seam occurrence conditions, making it difficult for the fully mechanized top coal caving mining theory to guide on-site production.

[0003] According to the ore discharge ellipsoid theory, mixed gangue is mainly caused by the discharge of gangue in the gangue funnel formed after the adjacent coal discharge port (support) is discharged by the discharge body boundary during coal discharge, that is, the gangue at the joint of the coal discharge ellipsoid and the adjacent gangue funnel is discharged. When one frame discharges coal, the top coal of the adjacent support will also be partially discharged, and the upper gangue will also be discharged. If one frame is discharged completely, the adjacent support will enter the coal flow system with gangue, and this part of the gangue will seriously affect the clean coal yield. Therefore, among the coal losses in the fully mechanized caving working face, the coal losses caused by the coal discharge process account for about half of the losses of the working face or more.

[0004] Based on this, how to reduce the gangue content of coal and improve the top coal recovery rate has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a multi-round regional coal caving method for thick coal seams.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A multi-round regional coal caving method for thick coal seams, comprising:

[0008] Obtain the basic parameters of the coal caving working face; the basic parameters of the coal caving working face include: top coal thickness h, working face length l, coal caving step distance d, scraper conveyor transportation capacity Q, coal bulk density r, coal tensile strength σ t , the internal cohesion of coal c, the height of coal discharge port h z The distance h below the coal gangue boundary line above the coal discharge port m ;

[0009] According to the basic parameters of the coal caving working face and the coal caving capacity of the coal caving openings, the number of coal caving openings n is determined, and the coal caving of the working face is carried out in groups. The number of coal caving openings included in the first group is 4x+1, and the number of coal caving openings included in each of the remaining groups is 4x, and the last group is the remainder of n-1 / 4x; where x is defined as the maximum number of coal caving openings that can be allowed to caving coal at the same time minus 1;

[0010] Starting from one side of the coal mining face, the first coal discharge opening is defined as the first-level coal discharge opening a. 1 , the interval of three coal discharge ports is the second level coal discharge port a 2 , and so on to get i first-level coal discharge ports a i , and the number of first-level coal-discharging openings in the working face is obtained to be n / 4+1;

[0011] Each first-level coal discharge port a i There are three coal discharge ports between them, and the middle one among the three coal discharge ports is designated as the secondary coal discharge port b. i , from left to right is b 1 、b 2 、b 3 By analogy, the remaining two coal discharge ports are defined as level 3 coal discharge ports c i , from left to right is c 1 、c 2 、c 3 And so on;

[0012] Coal is discharged in groups. First, the first-level coal discharge port a in the first group is i Carry out coal discharge, first-level coal discharge port a i The number of simultaneous openings is x+1 in the first coal placing group, x in the other coal placing groups, and e in the number of coal placing rounds. ai , each coal placement time is t a ;

[0013] Waiting for the first group of first-level coal discharge port a i After the coal discharge is completed, open the first group of secondary coal discharge ports b i , Secondary coal discharge port b i The number of simultaneous openings is x, and the number of coal-laying wheels is e bi , each coal placement time is t b ;

[0014] Waiting for the first group of secondary coal discharge port b i After the coal discharge is completed, open the first group of three-level coal discharge ports c i , three-level coal discharge port c i The number of simultaneous openings is 2x, and the number of coal-laying rounds is e ci , each coal placement time is t c ;

[0015] After the first group of coal placing processes is completed, the second and third groups of coal placing processes are carried out in sequence until all coal placing openings in the working face have carried out coal placing and the coal placing process is completed.

[0016] Preferably, the calculation formula for the number of coal discharge ports is:

[0017] Preferably, the calculation formula for the maximum number x of primary coal discharge openings that can allow simultaneous coal discharge is: Where A is a constant coefficient.

[0018] Preferably, the calculation formula for the number of coal discharge rounds at the first-level coal discharge port is: In the formula, e ai is the number of coal discharge rounds at the first-level coal discharge port, x 放 It is the number of all coal discharge openings for this coal discharge and those that have been discharged.

[0019] Preferably, the calculation formula for each coal discharge time of the first-level coal discharge port in the first group is: Where g is the acceleration due to gravity.

[0020] Preferably, the calculation formula for the number of coal discharge rounds at the secondary coal discharge port is: Where: e bi It is the number of coal discharge rounds at the secondary coal discharge port.

[0021] Preferably, the calculation formula for each coal discharge time of the secondary coal discharge opening in the first group is: Where g is the acceleration due to gravity.

[0022] Preferably, the calculation formula for the number of coal discharge rounds of the three-level coal discharge port is: Where: e ci It is the number of coal discharge rounds at the third-level coal discharge port.

[0023] Preferably, the calculation formula for each coal discharge time of the three-level coal discharge ports in the first group is: Where g is the acceleration due to gravity.

[0024] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0025] The present invention is based on the geological conditions and relevant parameters of the fully-mechanized caving working face, obtains the number of coal caving openings through reasonable calculation, determines the number of coal caving groups of the working face, and determines the first-level, second-level and third-level coal caving openings in sequence according to the advancing direction of the working face; firstly, coal is caved into the first-level coal caving openings of the first group, then into the second-level coal caving openings of a group, and finally into the third-level coal caving openings of a group; after multiple rounds of coal caving in each group in sequence, it is ensured that the top coal is fully recovered, thereby realizing an improvement in the top coal recovery rate of the working face. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 A flow chart of a method provided by an embodiment of the present invention;

[0028] Figure 2 A flow chart of a coal discharge process provided by an embodiment of the present invention;

[0029] Figure 3 A cross-sectional diagram of multiple rounds of regional coal caving provided in an embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 1- coal caving opening, 2- first-level coal caving opening coal caving area, 3- second-level coal caving opening coal caving area, 4- third-level coal caving opening coal caving area. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The purpose of the present invention is to provide a multi-round regional coal caving method for thick coal seams, which can improve the top coal recovery rate of the working face.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Figure 1 A flow chart of a method provided by an embodiment of the present invention, such as Figure 1 As shown, the present invention provides a method for multi-round regional coal caving in thick coal seams, comprising:

[0036] Step 100: Obtain basic parameters of the coal caving working face; the basic parameters of the coal caving working face include: top coal thickness h, working face length l, coal caving step distance d, scraper conveyor transportation capacity Q, coal bulk density r, coal tensile strength σ t , the internal cohesion of coal c, the height of coal discharge port h z The distance h below the coal gangue boundary line above the coal discharge port m ;

[0037] Step 200: According to the basic parameters of the coal caving working face and the coal caving capacity of the coal caving openings, the number of coal caving openings n is determined, and the coal caving of the working face is carried out in groups. The number of coal caving openings included in the first group is 4x+1, and the number of coal caving openings included in each of the remaining groups is 4x, and the last group is the remainder of n-1 / 4x; wherein x is defined as the maximum number of coal caving openings that can be allowed to caving coal at the same time minus 1;

[0038] Step 300: Starting from one side of the coal mining face, the first coal discharge opening is set as the first-level coal discharge opening a 1 , the interval of three coal discharge ports is the second level coal discharge port a 2 , and so on to get i first-level coal discharge ports a i , and the number of first-level coal-discharging openings in the working face is obtained to be n / 4+1;

[0039] Step 400: Each first-level coal discharge port a i There are three coal discharge ports between them, and the middle one among the three coal discharge ports is designated as the secondary coal discharge port b. i , from left to right is b 1 、b 2 、b 3 By analogy, the remaining two coal discharge ports are defined as level 3 coal discharge ports c i , from left to right is c 1 、c 2 、c 3 And so on;

[0040] Step 500: Coal is discharged in groups. First, the first-level coal discharge port a in the first group is i Carry out coal discharge, first-level coal discharge port a i The number of simultaneous openings is x+1 in the first coal placing group, x in the other coal placing groups, and e in the number of coal placing rounds. ai , each coal placement time is t a ;

[0041] Step 600: Wait for the first group of first-level coal discharge ports a i After the coal discharge is completed, open the first group of secondary coal discharge ports b i , Secondary coal discharge port b i The number of simultaneous openings is x, and the number of coal-laying wheels is e bi , each coal placement time is t b ;

[0042] Step 700: Wait for the first group of secondary coal discharge ports b i After the coal discharge is completed, open the first group of three-level coal discharge ports c i , three-level coal discharge port c i The number of simultaneous openings is 2x, and the number of coal-laying rounds is e ci , each coal placement time is t c ;

[0043] Step 800: After the first group of coal placing processes are completed, the second and third groups of coal placing processes are carried out in sequence until all coal placing openings of the working face have carried out coal placing and the coal placing process is completed.

[0044] Specifically, x is defined as follows: since the first-level caving openings are far apart (three caving openings are spaced apart in the first-level caving openings, one caving opening is spaced apart in the second-level caving openings, and the third-level caving opening is the last to caving), the first-level caving opening has the largest caving range and the largest caving volume among the three caving openings, and the caving speed is close to the caving speed of a single caving opening that is not affected. At this time, assuming that the transport capacity of the scraper conveyor is 1500t / h, and the caving speed of a single caving opening that is not affected is 300t / h, that is, x is 1500 / 300-1=4.

[0045] like Figure 2 As shown, a thick coal seam multi-round regional coal caving process in this embodiment has the following main processes:

[0046] ①. Record the top coal thickness h, working face length l, coal placement step d, scraper conveyor transport capacity Q, coal bulk density r, coal tensile strength σ t , the internal cohesion of coal c, the height of coal discharge port 1 h z , the coal gangue boundary line above the coal discharge port 1 moves down by a distance h m ;

[0047] ②. According to the basic parameters of the coal caving working face and the coal caving capacity of the coal caving opening 1, determine the number n of coal caving openings 1, and caving the working face in groups. The first group contains 4x+1 coal caving openings 1, and the remaining groups contain 4x coal caving openings 1. The last group is (n-1)%(4x), which is the remainder of n-1 / 4x.

[0048] ③. If Figure 3 As shown, starting from one side of the coal mining face, the first coal discharge opening 1 is defined as the first-level coal discharge opening a i , denoted as a 1 , which is located in the first-level coal discharge area 2, and the second first-level coal discharge area is three coal discharge areas 1 apart, denoted as a 2 , and so on, the number of first-level coal discharge ports in the working face is

[0049] ④、Each first-level coal discharge port a i There are three coal discharge ports 1 between them, and the middle one among the three coal discharge ports 1 is defined as the secondary coal discharge port b. i , from left to right is b 1 、b 2 、b 3 By analogy, it is located in the second-level coal discharge area 3, and the other two coal discharge ports 1 are defined as the third-level coal discharge ports c. i, from left to right is c 1 、c 2 、c 3 By analogy, it is located in the coal discharge area 4 of the third-level coal discharge port;

[0050] ⑤. Coal is discharged in groups. First, the first-level coal discharge port a in the first group i Carry out coal discharge, first-level coal discharge port 1a i The number of simultaneous openings is x+1 in the first coal placing group, x in the other coal placing groups, and e in the number of coal placing rounds. ai , each coal placement time is t a ;

[0051] ⑥, Wait for the first group of first-level coal discharge port a i After the coal discharge is completed, open the first group of secondary coal discharge ports b i , Secondary coal discharge port b i The number of simultaneous openings is x, and the number of coal-laying wheels is e bi , each coal placement time is t b ;

[0052] ⑦, Wait for the first group of secondary coal discharge port b i After the coal discharge is completed, open the first group of three-level coal discharge ports c i , three-level coal discharge port c i The number of simultaneous openings is 2x, and the number of coal-laying rounds is e ci , each coal placement time is t c ;

[0053] ⑧. After the first coal-discharging process is completed, the second and third coal-discharging processes are carried out in sequence until all coal-discharging ports 1 of the working face have completed coal-discharging, and the coal-discharging process is completed.

[0054] in, Where: n is the number of coal caving openings 1, h is the thickness of top coal in the working face, l is the length of the working face, σ t is the tensile strength of coal, and c is the cohesive force c of coal.

[0055] Further, In the formula: x+1 is the maximum number of first-level coal discharge ports that can discharge coal at the same time, d is the coal discharge step distance, A is a constant coefficient, which is related to the strength of coal and is taken as 1.2~1.6, r is the bulk density of coal, and Q is the hourly transportation capacity of the scraper conveyor.

[0056] Specifically, Where: e ai is the coal discharge round at the first-level coal discharge port, x 放 The number of all coal discharge ports 1 for this coal discharge and those that have been discharged; Where: t a is the coal discharge time of the first-level coal discharge port, hz Height of coal discharge port 1, h m is the downward movement distance of the coal-gangue boundary line above the coal discharge port 1, and g is the gravitational acceleration

[0057] Optionally, Where: e bi It is the coal discharge round for the secondary coal discharge port; Where: t b It is the coal releasing time at the secondary coal releasing port.

[0058] Furthermore, Where: e ci The coal discharge shifts for the three-level coal discharge port; Where: t c It is the coal releasing time at the third-level coal releasing port.

[0059] The thick coal seam multi-round regional coal caving process of the present invention is taken as an example in a coal mine in Shanxi:

[0060] ①. The coal seam thickness of the calibrated working face is 7.5m, the top coal thickness is 3.5m, the working face length is 200m, the coal discharge step distance is 3m, the scraper conveyor transportation capacity is 2000t, the coal bulk density is 1.4, the coal tensile strength is 1.1Mpa, the coal cohesion is 4Mpa, the height of the coal discharge port 1 is 3m, and the downward distance of the coal gangue boundary line above the coal discharge port 1 is 1.25m;

[0061] ②. Determine the number of coal openings 1 based on the basic parameters of the working face and the physical parameters of the coal. Then the coal is discharged in groups at the working face. The first group includes coal discharge port 1. That is, 4x+1=13, the number of coal discharge ports 1 included in each of the remaining groups is 12, and the number of coal discharge ports 1 included in the last group is 5;

[0062] ③. Starting from one side of the coal mining face, the first coal discharge opening 1 is defined as the first-level coal discharge opening a. i , denoted as a 1 , the interval of three coal discharge ports 1 is the second level coal discharge port, denoted as a 2 , and so on, the number of first-level coal discharge ports 1 in the working face is calculated to be

[0063] ④、Each first-level coal discharge port a i There are three coal discharge ports 1 between them, and the middle one among the three coal discharge ports 1 is defined as the secondary coal discharge port b. i The other two coal discharge ports 1 are set as the third-level coal discharge ports c i ;

[0064] ⑤. Coal is discharged in groups. First, the first-level coal discharge port a in the first group i Carry out coal discharge, first-level coal discharge port a iThe number of simultaneous openings is 4 in the first coal discharge group, and 3 or less in the other coal discharge groups. The number of coal discharge rounds is The first coal discharge time is Second;

[0065] ⑥、Wait for the first level coal discharge port a i After the coal is discharged, open the secondary coal discharge port bi and the secondary coal discharge port b. i The number of simultaneous openings is 3, and the number of coal wheels is Coal discharge time is Second;

[0066] ⑦, Wait for the second level coal discharge port b i After the coal discharge is completed, open the third-level coal discharge port c i , three-level coal discharge port c i The number of simultaneous openings is 6, and the number of coal wheels is Coal discharge time is Second;

[0067] ⑧. After the first coal-discharging process is completed, the second and third coal-discharging processes are carried out in sequence until all coal-discharging ports 1 of the working face have completed coal-discharging, and the coal-discharging process is completed.

[0068] The beneficial effects of the present invention are as follows:

[0069] The multi-round regional coal caving process in thick coal seams provided by the present invention can effectively improve the top coal caving effect, reduce top coal waste, and reduce residual un-caved top coal by reasonably grouping and grading the coal caving openings, thereby improving the top coal recovery rate, reducing coal losses, and improving economic benefits.

[0070] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0071] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for multi-round regional coal caving in thick coal seams, characterized in that: include: Obtain basic parameters of coal caving working face; The basic parameters of the coal caving working face include: top coal thickness h , working surface length l , Coal caving step distance d , Scraper conveyor transport capacity Q , bulk density of coal r , tensile strength of coal σ t , Coal cohesion c , Coal discharge port height h z Distance from the coal gangue dividing line above the coal caving opening h m ; According to the basic parameters of the coal caving working face and the coal caving capacity of the coal caving openings, the number of coal caving openings is determined. n , the coal is discharged in groups at the working face, and the number of coal discharge ports in the first group is 4x+1 , the number of coal discharge ports in each of the remaining groups is 4x , the last group is n-1 / 4x The remainder of x It is defined as the maximum number of primary caving openings that can allow coal to be caved simultaneously minus 1; Starting from one side of the coal mining face, the first coal caving opening is designated as the first-level coal caving opening. a 1 , the second level coal discharge port is three coal discharge ports apart a 2 , and so on. i First level coal discharge port a i , and the number of first-level coal discharge openings in the working face is n / 4+1 ; Each level of coal discharge port a i Interval 3 A coal vent, 3 The middle one among the coal discharge ports is designated as the secondary coal discharge port. b i , from left to right: b 1 , b 2 , b 3 By analogy, the remaining two coal discharge ports are designated as level 3 coal discharge ports. c i , from left to right: c 1 , c 2 , c 3 And so on; Coal is discharged in groups. First, the first level of the first group of coal discharge ports is a i Carry out coal discharge, first-level coal discharge port a i The number of simultaneous openings in the first coal discharge group is x+1 The remaining coal-laying groups are x , the number of coal-laying rounds is e ai , each coal placement time is t a ; Waiting for the first group of first-level coal discharge port a i After the coal discharge is completed, open the first set of secondary coal discharge ports b i , Secondary coal discharge port b i The number of simultaneous openings is x , the number of coal-laying rounds is e bi , each coal placement time is t b ; Waiting for the first group of secondary coal discharge ports b i After the coal discharge is completed, open the first set of three-level coal discharge ports c i , three-level coal discharge port c i The number of simultaneous openings is 2x , the number of coal-laying rounds is e ci , each coal placement time is t c ; After the first group of coal placing process is completed, the second and third groups of coal placing process are carried out in sequence until all coal placing openings of the working face have been coal placed, and the coal placing process is completed; The calculation formula for the number of coal discharge ports is: ; The maximum number of coal discharge openings that can be allowed to discharge coal at the same time x The calculation formula is: in, A is a constant coefficient; The calculation formula for the number of coal discharge rounds at the first-level coal discharge port is: ; In the formula, e ai is the number of coal discharge rounds at the first-level coal discharge port, x 放 The number of all coal caving openings for this coal caving and those that have been caving; The calculation formula for each coal discharge time of the first-level coal discharge port in the first group is: ; In the formula, g is the acceleration due to gravity; The calculation formula for the number of coal discharge rounds at the secondary coal discharge port is: ; Where: e bi The number of coal discharge rounds at the secondary coal discharge port; The calculation formula for each coal discharge time of the secondary coal discharge port in the first group is: ;The calculation formula for the number of coal discharge rounds at the third-level coal discharge port is: ; Where: e ci The number of coal discharge rounds at the third-level coal discharge port; The calculation formula for each coal discharge time of the three-level coal discharge port in the first group is: .

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