Sublevel method of stoping of backfilling of steeply inclined ore bodies

Abstract

The application discloses a kind of interval filling mined-out area stoping inter-column methods of steep ore body, it is related to underground mining technical field.The inter-column method of stoping includes: obtaining interval mined-out area quantity, according to interval mined-out area quantity, obtaining to be filled mined-out area;The inter-column on the both sides of to be filled mined-out area is closed treatment;Fill to be filled mined-out area, collapse the inter-column in the mined-out area not filled;The inter-column that collapses is transported out through the ore drawing structure of recovery mine house between filled mined-out area.The way of gradually recovering inter-column is improved by interval filling, the efficiency and safety of inter-column stoping, reduce the loss of dilution of inter-column stoping, reduce the amount of development engineering, can also realize the effective management to mined-out area, realize the purpose of safe stoping.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground mining, in particular to a method for recovering inter-pillar in a stope area of a steeply inclined ore body by interval filling. BACKGROUND

[0002] In the history of mining medium-thick steeply inclined ore bodies, the open stope method is a commonly used mining method. In the recovery process, each sublevel is divided into ore rooms and ore pillars. After the recovery of the ore rooms, the ore pillars are left to support the stability of the stope area. The remaining ore pillars result in waste of mineral resources, and the unmanaged stope area also poses a huge safety hazard.

[0003] Current technologies for recovering residual ore pillars and managing stope areas directly caving the ore pillars (inter-pillars) can cause safety problems such as stope area collapse and surface subsidence. If the stope area is completely filled before the ore pillars are recovered, the engineering quantity is large, the recovery efficiency is low, and a large amount of dilution will be caused. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art or related art.

[0005] Therefore, the present application provides a method for recovering inter-pillars in a stope area of a steeply inclined ore body by interval filling, which improves the recovery efficiency and safety of the inter-pillars, reduces the loss and dilution of the inter-pillar recovery, reduces the amount of preparation engineering, and effectively manages the stope area to achieve the purpose of safe recovery.

[0006] Specifically, the technical solution includes the following:

[0007] The present application provides a method for recovering inter-pillars in a stope area of a steeply inclined ore body by interval filling, which improves the recovery efficiency and safety of the inter-pillars, reduces the loss and dilution of the inter-pillar recovery, reduces the amount of preparation engineering, and effectively manages the stope area to achieve the purpose of safe recovery.

[0008] The number of interval stope areas is obtained, and a stope area to be filled is obtained according to the number of interval stope areas.

[0009] The inter-pillars on both sides of the stope area to be filled are sealed.

[0010] The stope area to be filled is filled, and the inter-pillars in the unfilled stope area are caved.

[0011] The caved inter-pillars are transported out through the ore extraction structure of the recovery ore room located between the filled stope areas.

[0012] Optionally, the method for recovering inter-pillars further includes:

[0013] The recovery ore room is filled.

[0014] The next stope area to be filled is obtained according to the number of interval stope areas.

[0015] Repeating the step of sealing the interval column on both sides of the to-be-filled goaf until all the interval columns in the middle section are recovered and the recovery mine chamber is filled.

[0016] Optionally, the mine where the steeply inclined ore body is located includes the interval column, and the top column and the bottom column arranged on both sides of the interval column, the interval column includes a manway, a crossheading and a ore extraction structure left during mining, the manway is located between the top column and the bottom column, the manway penetrates through the interval column, the crossheading is located in the middle section of the interval column, the crossheading communicates the manway with the goaf on both sides, and the ore extraction structure is located at the bottom of the recovery mine chamber and is arranged on the same side of the bottom column.

[0017] Optionally, the obtaining of the interval goaf quantity comprises:

[0018] Based on the Mathews stability chart method and the actual mining stope structure parameters of the mine, the interval goaf quantity N is obtained.

[0019] Optionally, the obtaining of the interval goaf quantity N comprises:

[0020] A Mathews stability coefficient N' is obtained, N'=Q'×A×B×C, wherein Q' is a modified value of Q, A is a rock stress coefficient, B is a joint occurrence adjustment coefficient, and C is a goaf exposed surface orientation adjustment coefficient, wherein Q is a rock mass classification, and Q' is a rock mass index;

[0021] According to the un-supported Mathews stability chart of the Mathews stability chart, a hydraulic radius R value is obtained through N';

[0022] According to a rectangular stope hydraulic radius formula, a theoretical maximum length value of the goaf is obtained: R=(a×b) / [2(a+b)], wherein a is a vertical strike span, that is, a goaf width, and an actual goaf width value of the mine is taken; and b is a strike span, and a theoretical maximum length value is calculated according to the formula;

[0023] According to the theoretical maximum length value, the actual goaf length of the mine and the interval column width, the interval goaf quantity N is obtained, N≤(b-l2) / (l1+l2), wherein l1 is the actual goaf length of the mine, which is a known value; l2 is the actual interval column width, which is a known value; and N is obtained by taking an integer.

[0024] Optionally, Q is a rock mass classification, Q' is a rock mass index, Q' is a modified rock mass classification Q, and Q' is obtained when a joint surface alteration degree coefficient and a ground stress influence factor coefficient value in the Q value are both 1: Q'= (RQD / J α )×(Jr / J n wherein RQD is a rock quality designation, J n is a number of joint sets, J r is a joint roughness coefficient, J α is a joint alteration coefficient.

[0025] Optionally, the closing treatment of the interval pillars on both sides of the to-be-filled goaf comprises:

[0026] filling soil in the manway ventilation shaft formed by the interval pillars;

[0027] wherein the soil is surface soil of the mining area.

[0028] Optionally, the filling of the to-be-filled goaf comprises:

[0029] walling up the ore extraction structure;

[0030] filling the bottom layer of the to-be-filled goaf on both sides of the interval goaf, with a filling height of 8m to 10m;

[0031] filling the upper layer of the to-be-filled goaf.

[0032] Optionally, the filler for filling the to-be-filled goaf is a mixture of lime sand and water, the mass ratio of the lime sand is more than 72%, the mass ratio of the lime sand is 1:4 to 1:6 when filling the bottom layer, the bottom layer filling strength is greater than 5MPa; the mass ratio of the lime sand is 1:15 when filling the upper layer, and the upper layer filling strength is greater than 2MPa.

[0033] Optionally, the interval pillars in the caving unfilled goaf comprise:

[0034] a top heading drill roadway and a bottom heading drill roadway are arranged on both sides of the interval pillars;

[0035] based on the top heading drill roadway and the bottom heading drill roadway, blast hole arrangement is performed in the interval pillars, and the interval pillars are caved.

[0036] The interval pillar recovery method for the backfilling goaf of the steeply inclined ore body provided by the embodiment of the present application, wherein the interval pillar recovery method comprises the following steps: firstly, the number of the interval goaf is obtained; and then, the goafs on both sides of the interval goaf are filled to form a recovery mine room; before filling the goafs on both sides of the interval goaf, the interval pillar is sealed to prevent the filling material of the filled goaf from entering the recovery mine room and affecting the ore extraction of the subsequent interval pillar; after the sealing of the interval pillar is completed, the goafs to be filled on both sides of the interval goaf are filled; then, the blast hole arrangement of the interval pillar in the interval goaf is performed; then, the interval pillar in the middle section is caved and transported out through the bottom structure of the recovery mine room, so as to realize the recovery of the interval pillar. Through the interval pillar recovery method, the recovery efficiency and safety of the interval pillar can be improved, the loss and dilution of the interval pillar recovery are reduced, the amount of the preparation engineering is reduced, and the management of the goaf can be realized to prevent the problems of the caving and the surface subsidence, and the safety of the goaf can be improved.

[0037] The above description is only a summary of the technical scheme of the present application. In order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following will describe the specific embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative labor.

[0039] Figure 1 The step flow chart of the interval pillar recovery method according to an embodiment of the present application;

[0040] Figure 2a The structural schematic diagram of the interval pillar recovery according to an embodiment of the present application;

[0041] Figure 2b The A-A direction schematic diagram of the embodiment shown in Figure 2a

[0042] Figure 3 The schematic diagram of the unsupported Mathews stability chart of the Mawdesley extended Mathews stability chart according to an embodiment of the present application.

[0043] Wherein, Figure 2a And Figure 2b The correspondence between the reference signs and the component names in the drawings is as follows:

[0044] ​1: pillar, 2: top pillar, 3: bottom pillar, 4: lower packing body, 5: upper packing body, 6: soil, 7: ore extraction structure, 8: recovery room, 9: top drilling roadway, 10: bottom drilling roadway, 11: manway, 12: crossheading, 13: blast hole arrangement. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0046] Before the further detailed description of the embodiments of the present application, the orientation nouns such as "upper", "lower", "side" in the embodiments of the present application do not have the meaning of limiting the scope of protection of the present application.

[0047] In order to make the technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0048] Figure 1 A step flow chart of the pillar recovery method according to an embodiment of the present application.

[0049] As shown in Figure 1 An embodiment of the present application provides a pillar recovery method for gap filling goaf of steeply inclined ore body, the pillar recovery method comprising:

[0050] Step 1: obtaining the number of gap goafs, and obtaining the goafs to be filled according to the number of gap goafs;

[0051] Step 2: sealing the pillars on both sides of the goafs to be filled;

[0052] Step 3: filling the goafs to be filled and caving the pillars in the unfilled goafs;

[0053] Step 4: transporting the caved pillars out through the ore extraction structure of the recovery room located between the filled goafs.

[0054] The method for stoping the middle column comprises the following steps: first, the number of the interval goaf is obtained, and the interval goaf is formed by filling the goafs on both sides of the interval goaf; before filling the goafs on both sides of the interval goaf, the middle column is sealed to prevent the filling material from entering the recovery room and affecting the ore drawing of the middle column; after the sealing of the middle column is completed, the goafs on both sides of the interval goaf are filled, and then the middle column in the interval goaf is arranged with blast holes, the middle column in the middle section is caved, and the middle column is transported out through the bottom structure of the recovery room, so that the middle column is stoped. The method for stoping the middle column can improve the stoping efficiency and safety of the middle column, reduce the loss and dilution of the middle column, reduce the amount of preparation engineering, and can also realize the treatment of the goaf, prevent the occurrence of the problems of caving and surface subsidence, and improve the safety of the goaf.

[0055] Specifically, the loss is the ore that cannot be mined during mining, and the dilution is that other non-ore objects such as waste rock and filling material are mixed in the ore during mining, which reduces the grade of the mined ore. In the related art, the middle column is stoped after the goaf is filled, which needs to wait for the hardening of the filling body and needs to re-excavate the stoping roadway and ore drawing structure. Since the middle column is stoped after the goaf is filled with filling material, part of the ore in the original goaf cannot be mined during mining, and the filling material is mixed in the middle column during mining, which causes loss and dilution. In the present application, the middle column is stoped before the goaf is filled, which does not need to wait for the hardening of the filling body and does not need to wait for the excavation of the ore drawing structure, so the stoping efficiency is improved; part of the residual ore in the original goaf can be blasted during mining, and the filling material is not mixed, so the loss and dilution are reduced; the preparation is a key preparation stage in mining engineering, that is, a preparation engineering, and the main task is to divide the ore block by excavating the roadway to create conditions for subsequent drilling, ventilation, transportation and other operations. The related art includes the excavation of the stoping roadway and the ore drawing structure. The present application does not need to excavate the ore drawing structure, and the amount of excavation of the stoping roadway is also reduced, so the amount of preparation engineering is reduced.

[0056] In a possible implementation, the method for stoping the middle column further comprises:

[0057] Step 5, filling the recovery room;

[0058] Step 1, obtaining the next to-be-filled goaf according to the number of the interval goaf;

[0059] Repeat the steps after the sealing treatment of the middle column on both sides of the to-be-filled goaf until all the middle columns in the middle section are recovered and the recovery room is filled.

[0060] Wherein, after the caving and removal of the inter-pillar 1 in the recovery room 8, the recovery room 8 is filled in the same way as the filling of the goaf to be filled; the goaf to be filled is filled gradually from one side to the other side, and the inter-pillar 1 in the recovery room 8 is recovered, after the recovery of the inter-pillar 1 in one group of recovery rooms 8 and the filling of the recovery room 8, the filling and recovery of the inter-pillar 1 in the next group of goaf to be filled is carried out, and so on until the recovery of all the inter-pillars 1 in the middle section (the outermost two inter-pillars 1 are not recovered) and the filling of all the goafs is completed. After the filling of the recovery room 8 is completed, it is determined whether all the goafs are filled, if yes, the process is ended, otherwise, the filling of the goaf to be filled after the interval goaf is carried out.

[0061] It can be understood that the recovery room 8 is the interval goaf, if the number of interval goafs is 1, then from one side to the other side of the goaf, the goaf is numbered as No. 1 goaf, No. 2 goaf, …, No. X goaf, then No. 1 goaf and No. 3 goaf are filled first, No. 2 goaf is set as the recovery room 8, after the filling of the recovery room 8, No. 5 goaf is filled, and No. 4 goaf is set as the recovery room 8; if the number of interval goafs is 2, then No. 1 goaf and No. 4 goaf are filled first, and No. 2 goaf and No. 3 goaf in the middle are set as the recovery room 8, after the filling of the recovery room 8, No. 7 goaf is filled, and No. 5 goaf and No. 6 goaf are set as the recovery room 8, and so on.

[0062] Figure 2a A schematic diagram of the structure of the recovery inter-pillar according to an embodiment of the present application; Figure 2b A-A direction schematic diagram of the embodiment shown in Figure 2a

[0063] It should be noted that, as shown in Figure 2a and Figure 2b , the mine where the steeply inclined ore body is located includes the inter-pillar 1, and the top pillar 2 and the bottom pillar 3 arranged on both sides of the inter-pillar 1, the inter-pillar 1 includes the personnel ventilation shaft 11, the communication passage 12 and the ore removal structure 7 left over during mining, the personnel ventilation shaft 11 is located between the top pillar 2 and the bottom pillar 3, the personnel ventilation shaft 11 penetrates the inter-pillar 1, the communication passage 12 is located in the middle section of the inter-pillar 1, the communication passage 12 communicates the personnel ventilation shaft 11 with the goafs on both sides, and the ore removal structure 7 is located at the bottom of the recovery room 8, and the ore removal structure 7 is arranged on the same side as the bottom pillar 3.

[0064] Wherein, each part described above is a necessary passage during mining, the present application aims to recover the group of pillar goafs left over from the existing mining from bottom to top in the order of the middle section, and there are multiple layers of mine pillars under the mine as shown in Figure 2a , wherein the top pillar 2 and the bottom pillar 3 also need to be recovered, but are not within the scope of the present application, the present application mainly realizes the recovery of the inter-pillar 1, and the recovery is shown in the attached Figure 2a ​The stepwise backfilling of the goaf (including the to-be-filled goaf and the recovered room 8) is performed from left to right in sequence.

[0065] In an implementable embodiment, the obtaining of the number of interval goafs comprises:

[0066] Based on the Mathews stability chart method and the actual mining stope structure parameters of the mine, the number of interval goafs N is obtained.

[0067] It should be noted that the theoretical maximum goaf length calculated by the Mathews stability chart method can ensure the stability of the goaf.

[0068] Specifically, the obtaining of the number of interval goafs N comprises:

[0069] The Mathews stability coefficient N' is obtained, N' = Q' × A × B × C, wherein Q' is a modified value of Q, A is a rock stress coefficient, B is a joint occurrence adjustment coefficient, and C is a goaf exposed surface orientation adjustment coefficient, wherein Q is a rock mass quality classification, and Q' is a rock mass quality index;

[0070] According to the unlined Mathews stability chart of the Mathews stability chart, the hydraulic radius R value is obtained by N';

[0071] According to the rectangular stope hydraulic radius formula, the theoretical maximum length value of the goaf is obtained: R = (a × b) / [2 (a + b)], wherein a is a vertical strike span, that is, the width of the goaf, and the actual width value of the mine goaf is taken; b is a strike span, and the theoretical maximum length value is calculated by the formula;

[0072] According to the theoretical maximum length value, the actual goaf length of the mine, and the interval pillar width, the number of interval goafs N is obtained, N ≤ (b - l2) / (l1 + l2), wherein l1 is the actual goaf length of the mine, which is a known value; l2 is the actual interval pillar width, which is a known value; and N is obtained by taking the integer part downward.

[0073] Wherein, A is a rock stress coefficient, B is a joint occurrence adjustment coefficient, and C is a goaf exposed surface orientation adjustment coefficient, A, B, and C are obtained by the Mathews stability chart.

[0074] It should be noted that Q' is obtained when the joint surface alteration degree coefficient and the ground stress influence factor coefficient value in Q value are both 1: Q' = (RQD / J α ) × (J r / J n ), wherein RQD is a rock mass quality index, J n is a joint set number, J r is a joint roughness coefficient, and J αLet Q be the joint alteration coefficient, Q be the rock mass quality grade, Q' be the rock mass quality index, and Q' be the modified rock mass quality grade. This formula is a conventional calculation formula in this field and will not be elaborated further.

[0075] Specifically, within the group of pillar voids left by the stope method, the number N of interleaved goafs is determined using the Mathews stability chart method and actual stope structure parameters from the mine. At the terminal level, preparations are first made to fill the first goaf ( Figure 2a The first goaf and the N+2 goaf are designated as the goaf to be filled. The N goafs in the middle form the recovery stope 8. First, the ventilation shaft 11 and connecting passage 12 in the intermediate column 1 are filled to prevent the filling slurry from flowing into the recovery stope 8 and blocking the bottom ore extraction structure 7 of the recovery stope 8, thus affecting the ore extraction of the intermediate column 1. Then, the first and N+2 goafs are filled. After the filling material solidifies and reaches the required strength, the N goafs in the middle of the first and N+2 goafs, i.e., the recovery stope 8, are used as the blasting free face to blast the intermediate column 1 in the intermediate recovery stope 8. The blasted intermediate column 1 is then transported out through the bottom roadway using the ore extraction structure 7 left at the bottom of the recovery stope 8. After the blasting of the interstitial pillar 1 in the middle part between the first and N+2 goafs, i.e., within the recovery stope 8, is completed, the recovery stope 8 is also filled, completing the first ore extraction from the interstitial pillar 1 and the filling of the goaf. Then, the 2N+3 goaf is filled, forming the recovery stope 8 between the N+2 goaf (already filled) and the 2N+3 goaf. The interstitial pillar 1 within this recovery stope 8 is blasted and collapsed, and the collapsed interstitial pillar 1 is transported out through the ore extraction structure 7 at the bottom of the recovery stope 8. Finally, the recovery stope 8 is filled. Then, 3N+4 goafs are filled, and after filling the recovery stope 8 between the 2N+3 and 3N+4 goafs, 4N+5 goafs are filled, and this process is repeated until all interstitial pillar 1s have collapsed and all goafs (goafs to be filled and recovery stopes 8) have been filled.

[0076] It should be noted that, in the direction of mining depth, the filling of goaf, the filling of inter-column 1 and the recovery of ore chamber 8 are carried out from bottom to top. In the horizontal direction (length), the filling steps of filling every N are repeated until the treatment of all goaf and the recovery of inter-column 1 are completed.

[0077] In one feasible implementation, sealing the columns on both sides of the goaf to be filled includes:

[0078] Soil was filled into the pedestrian ventilation shafts formed by the intercolumnar columns;

[0079] The soil in question is the surface soil of the mining area.

[0080] It should be noted that the inter-column 1 is provided with a manway ventilation shaft 11 and a connecting passage 12 connected to the goaf, in order to prevent the slurry of the filling material from flowing into the recovery room 8 through the inter-column 1 during the filling of the goaf, it is necessary to block the manway ventilation shaft 11 and the connecting passage 12 in front of the goaf on both sides of the recovery room 8. The inter-column 1 on the side of the goaf facing the recovery room 8 is mainly blocked, which can be filled and compacted with the existing surface soil on the mine. Since the natural repose angle of the soil 6 is usually 30° to 40°, the soil 6 will solidify together with the filling material on both sides of the goaf after being in contact with the filling material in the connecting passage 12, so that the filling material on both sides of the goaf will not enter the recovery room 8 through the connecting passage 12 while the manway ventilation shaft 11 is filled, thereby achieving good blocking effect.

[0081] Specifically, during the filling of the goaf on both sides of the recovery room 8, it can be observed whether the filling material slurry flows out from the bottom structure outlet of the recovery room 8. It can be checked whether the filling material slurry seeps into the recovery room 8 from the manway ventilation shaft 11 of the inter-column 1, and whether the filling material slurry runs during the filling of the goaf. If it is found that the filling material slurry flows out from the manway ventilation shaft 11, the filling of the goaf is stopped, and subsequent treatment is carried out. After the manway ventilation shaft 11 and the connecting passage 12 are completely closed again, the filling treatment of the goaf is continued.

[0082] In an embodiment, the filling of the goaf to be filled includes:

[0083] Blocking the ore-drawing structure with a wall;

[0084] Filling the bottom layer of the goaf to be filled on both sides of the interval goaf, and the filling height is 8m to 10m;

[0085] Filling the upper layer of the goaf to be filled.

[0086] The ore-drawing structure 7 is a structure left over from the original mining, which is similar to a fence structure with a sharp angle on top, which can make the collapsed inter-column 1 pass through the inclined slope of the sharp angle and be discharged from the outlet, avoiding accumulation in the recovery room 8. Since the goaf is provided with the ore-drawing structure 7, the ore-drawing structure 7 is blocked with cement before the goaf is filled with the filling material slurry, so as to prevent the filling material slurry from seeping out through the ore-drawing structure 7.

[0087] It should be noted that the filling material slurry for filling the goaf to be filled is a mixture of sand and water, and the mass ratio of the sand is more than 72%. The mass ratio of the sand is 1:4 to 1:6 during the bottom layer filling, and the bottom layer filling strength is greater than 5MPa. The mass ratio of the sand is 1:15 during the upper layer filling, and the upper layer filling strength is greater than 2MPa.

[0088] For example, the ash in the lime-sand mixture can be cement or cementitious powder, while the sand is tailings, which is mineral waste that can be directly taken from the mine. Generally, after being mixed in proportion to form a filler slurry and solidified, the strength generally does not change much. Usually, the strength of the lower filler body 4 is greater than 5MPa, and the strength of the upper filler body 5 is greater than 2MPa. The upper filler body 5 also serves as the base plate for the recovery of the bottom pillar of the upper mining area in the depth direction, so its strength cannot be lower than 2MPa.

[0089] It is understandable that the filling of the goaf and the recovery stope 8 can be achieved by laying pipelines into the goaf or drilling holes on the surface to fill the goaf and the recovery stope 8 with filler slurry, which is existing technology and will not be elaborated here.

[0090] In one feasible implementation, the interstitial pillars within the collapsed and unfilled goaf include:

[0091] Top excavation tunnels and bottom excavation tunnels are set on both sides of the column;

[0092] Based on the top-excavated borehole roadway and the bottom-excavated borehole roadway, blast holes are arranged in the inter-column to cause the inter-column to collapse.

[0093] After the sealing of the inter-column 1 is completed and the goaf to be filled is filled, the inter-column 1 is sealed on both sides above and below, that is, on both sides of the bottom and top of the ventilation shaft 11. Figure 2a One tunnel is excavated in each of the left and right directions, namely the top excavation borehole 9 and the bottom excavation borehole 10. The lengths of the top excavation borehole 9 and the bottom excavation borehole 10 are equal to the thickness of the support column 1. Figure 2b The distances between the left and right sides are the same. The connecting passage 12 in the original pedestrian ventilation shaft 11 serves as the boundary. Above and below the connecting passage 12, blast holes are arranged 13 via the top excavation borehole roadway 9 and the bottom excavation borehole roadway 10, respectively. Figure 2b As shown, multiple blast holes are arranged in a fan shape to improve the reliability of the collapse of the inter-pillar 1. After the inter-pillar 1 collapses, it forms fragments, which fall into the roadway below through the ore extraction structure 7 at the bottom of the recovery room 8. The ore is then transported out by mine cars to realize the recovery of the inter-pillar 1.

[0094] Example

[0095] Taking a mining area in a certain mine as an example, there are several goaf areas in a certain section of the mine, such as... Figure 2a The diagram shows the goaf areas along the strike line, numbered sequentially from left to right as 1, 2, 3, 4, 5, ... The goaf area spans approximately 30m along the strike line and 52m perpendicular to the strike line (perpendicular to the strike line refers to...). Figure 2a (In the direction of the middle and outside), the thickness of the intercolumnar column is 2m, that is Figure 2b The distance between the left and right sides.

[0096] The number of interval goaf N is determined using the Mathews stability chart method, and the Mathews stability coefficient N' is the ability of the rock mass to maintain stability under given stress conditions, and the calculation formula is:

[0097] N' = Q' x A x B x C (1)

[0098] In the formula, Q' is the modified value of Q, A is the rock stress coefficient, B is the joint occurrence adjustment coefficient, C is the exposure surface orientation adjustment coefficient of the goaf, Q is the rock mass classification, Q' is the rock mass index, and the rock mass classification Q is modified. When the joint surface alteration degree coefficient and the ground stress influence factor coefficient value in Q value are both 1, the following formula is obtained:

[0099] Q' = (RQD / J α ) x (J r / J n ) (2)

[0100] In the formula, RQD is the rock mass index, J n is the joint set number, J r is the joint roughness coefficient, and J α is the joint alteration coefficient. Formula (2) is a conventional formula in the art, and will not be described again.

[0101] The rock stress coefficient A is mainly related to the ratio of the uniaxial compressive strength σ c of the intact rock and the horizontal induced stress σ1 parallel to the exposed surface. When σ c / σ1 ≤ 2, A = 0.1; when 2 < σ c / σ1 < 10, A = 0.1125 ( σ c / σ1 ) - 0.125; and when σ c / σ1 ≥ 10, A = 1. The two values σ c and σ1 can be obtained by experiment and calculation, which belong to the existing obtaining method.

[0102] The joint occurrence adjustment coefficient B depends on the angle between the main joint set direction and the working face, and is obtained by the Mathews stability chart method. The angle α between the working face rock wall and the joint and the joint occurrence adjustment coefficient B are obtained by the chart, and according to the angle between the working face rock wall and the joint in the embodiment, B = 0.8 is obtained.

[0103] The exposure surface orientation adjustment coefficient C of the goaf can be estimated by the empirical formula (C = 8 - 6 cos α). The gravity adjustment coefficient of the two sides of the working face takes the maximum value 8, and the gravity adjustment coefficient of the roof of the horizontal working face takes the minimum value 2. Here, the Mathews stability chart method is used to obtain the exposure surface orientation adjustment coefficient C (gravity adjustment factor C) of the working face. According to the inclination of the working face in the embodiment, C = 5.4 is obtained.

[0104] Based on the mine rock mechanics data, based on the Mathews stability chart method, the parameters are Q'=8.73, A=0.95, B=0.80, C=5.4, then N'=35.84.

[0105] According to the corresponding relationship between the stability coefficient N' and the hydraulic radius R of the unsupported Mathews stability chart in the Mawdesley expanded Mathews stability chart, as shown in the accompanying Figure 3 As shown in the accompanying drawings, in the unsupported transition zone, when N'=35.84, a vertical line is drawn upward and intersects the second curve encountered, and then the longitudinal coordinate of the intersection point is the hydraulic radius R=13.18m. The vertical strike span of the stope is about a=52m, according to the hydraulic radius calculation formula of the rectangular stope R=(a×b) / [2(a+b)], the maximum span along the strike is b=55.63m, and the length of the mine along the stope is about l1=30m, the interval column thickness is l2=8m, and the number of goaf intervals N≤(b-l2) / (l1+l2)=(55.63-8) / (30+8)=1.25, so N is 1, that is, the number of filling is one interval for every one interval in the existing goaf. That is, according to the hydraulic radius calculation formula of the rectangular stope: R=(a×b) / [2(a+b)], where a is the vertical strike span, that is, the goaf width, and the actual goaf width value of the mine is taken; b is the span along the strike, which is the theoretical maximum length value calculated by the formula. N≤(b-l2) / (l1+l2). In the formula, l1 is the actual goaf length of the mine, and l2 is the actual interval column width, and finally N is rounded down.

[0106] Figure 2a The first goaf, the second goaf, the third goaf, the fourth goaf and the fifth goaf are sequentially arranged from left to right, and after the above calculation, the interval column between the first goaf and the third goaf is first sealed, and after the sealing is completed, the first goaf and the third goaf are simultaneously filled by the filler body, so that the lower filler body close to the bottom column reaches a strength of 5MPa or more, the height of the lower filler body is 8m to 10m, and the upper filler body close to the top column reaches a strength of 2MPa or more. The bottom ore extraction structure on both sides of the recovery mine needs to be sealed by cement wall before the goaf is filled. Then the explosives are placed in the blast hole, the interval column in the recovery mine is caved, and is transported out through the bottom ore extraction structure. Finally, the ore extraction structure is sealed by cement wall, and the recovery mine is filled with filler body, and the strength of the filler body and the goaf filler body is consistent.

[0107] It can be understood that the inter-columnar pillars needing to be blocked can be blocked first and then the goaf is gradually filled with the filler body, or the inter-columnar pillars are gradually filled, that is, the inter-columnar pillars on both sides of the goaf to be filled are blocked first, and then the inter-columnar pillars on both sides of the next goaf to be filled are blocked after the inter-columnar pillars are mined and the recovery mine is filled. If N=2, the second goaf and the third goaf are used as the recovery mine, and the recovery mine has three inter-columnar pillars, and the middle building can not be blocked and can be directly arranged with the blast hole.

[0108] The filler body filling of the fifth goaf is continued, the fourth goaf between the third goaf and the fifth goaf is used as the recovery mine, and then the above steps are repeated, the ore pillar in the fourth goaf is mined, the fourth goaf is filled, and then the seventh goaf is filled, and the above steps are repeated until the middle inter-columnar pillars in the goaf are completely recovered and the goaf is completely filled.

[0109] In the present application, the terms "first" and "second" are used only for descriptive purposes and are not to be construed as indicating or implying relative importance. The term "a plurality of" refers to two or more, unless otherwise expressly specified.

[0110] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the present application cover any and all variations of the present application comprising modifications, alterations, substitutions, and equivalents thereof that follow within the spirit and scope of the present application. The specification and examples are to be regarded as exemplary only.

[0111] The above only is the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of recovering the intervening pillars of a steeply inclined ore body by the method of backfilling of the mined-out area by spaced filling, characterised by the fact that, The method comprises: obtaining the number of interval goafs, and obtaining a to-be-filled goaf according to the number of interval goafs; performing sealing treatment on the interval pillars on both sides of the to-be-filled goaf; filling the to-be-filled goaf and collapsing the interval pillars in the unfilled goaf; transporting the collapsed interval pillars out through the ore drawing structure of the recovery mine located between the filled goafs; The method further comprises: filling the recovery mine; obtaining a next to-be-filled goaf according to the number of interval goafs; repeating the step of performing sealing treatment on the interval pillars on both sides of the to-be-filled goaf until the interval pillars in all middle sections are recovered and the recovery mine is filled; The mine where the steeply inclined ore body is located comprises the interval pillars, and the top and bottom pillars arranged on both sides of the interval pillars, the interval pillars comprise a manway ventilation shaft, a communication passage and the ore drawing structure left during mining, the manway ventilation shaft is located between the top and bottom pillars, the manway ventilation shaft penetrates through the interval pillars, the communication passage is located in the middle section of the interval pillars, the communication passage communicates the manway ventilation shaft with the goafs on both sides, and the ore drawing structure is located at the bottom of the recovery mine and is arranged on the same side of the bottom pillar; The method of obtaining the number of interval goafs comprises: obtaining the number N of interval goafs based on the Mathews stability chart method and the actual stope structure parameters of the mine; The method of obtaining the number N of interval goafs comprises: obtaining a Mathews stability coefficient N', N' = Q' × A × B × C, wherein Q' is a modified value of Q, A is a rock stress coefficient, B is a joint occurrence adjustment coefficient, and C is a goaf exposed surface orientation adjustment coefficient, wherein Q is a rock mass classification, and Q' is a rock mass index; obtaining a hydraulic radius R value through N' according to an unsupported Mathews stability chart of the Mathews stability chart; obtaining a theoretical maximum length value of the goaf according to a rectangular stope hydraulic radius formula: R = (a × b) / [2 (a + b)], wherein a is a vertical strike span, that is, a goaf width, and the actual goaf width value of the mine is taken; b is a strike span, and a theoretical maximum length value is calculated according to the formula; obtaining the number N of interval goafs according to the theoretical maximum length value, the actual goaf length of the mine and the interval pillar width, N ≤ (b - l2) / (l1 + l2), wherein l1 is the actual goaf length of the mine, which is a known value; l2 is the actual interval pillar width, which is a known value; and N is obtained by taking an integer.

2. The method for the retreatment of the pillars between the stope areas of the steeply inclined ore body by the method of the panel-by-panel backfilling of the mined-out areas according to claim 1, characterized in that, Q is rock mass quality classification, Q' is rock mass quality index, Q' is modified rock mass quality classification Q, Q' is obtained when the joint surface alteration degree coefficient and the ground stress influence factor coefficient value in Q value are both 1: Q'= (RQD / J α ) x (J r / J n ), in the formula, RQD is rock quality index, J n is joint group number, J r is joint roughness coefficient, J α is joint alteration coefficient.

3. The method for the retreatment of the pillars between the stope areas of the steeply inclined ore body by the method of the panel retreatment by the sublevel backfilling according to claim 1, characterized in that, The sealing treatment on the interval pillars on both sides of the to-be-filled goaf comprises: filling soil in the manway ventilation shaft formed by the interval pillars; The soil is surface soil of the mine area.

4. The method for the retreatment of the pillars between the stope areas of the steeply inclined ore body by the method of the panel-by-panel backfilling of the mined-out areas according to claim 1, characterized in that, The filling of the to-be-filled goaf comprises: blocking the ore drawing structure by walling; filling the bottom layer of the to-be-filled goaf on both sides of the interval pillars, and the filling height is 8 m to 10 m; filling the upper layer of the to-be-filled goaf.

5. The method of claim 4, wherein, The filler for filling the goaf to be filled is a mixture of lime sand and water, the mass ratio of the lime sand is more than 72%, the mass ratio of the lime sand is 1:4 to 1:6 when filling the bottom layer, the filling strength of the bottom layer is greater than 5MPa; the mass ratio of the lime sand is 1:15 when filling the upper layer, the filling strength of the upper layer is greater than 2MPa.

6. The method for the retreatment of the pillars between the stope areas of the steeply inclined ore body by the method of the panel retreatment by the sublevel backfilling according to claim 1, characterized in that, The inter-column in the caving goaf not filled includes: Top and bottom drilling roadway are arranged on both sides of the inter-column; Based on the top and bottom drilling roadway, blast hole arrangement is carried out in the inter-column, and the inter-column is caved.

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