A method of ventilating when mining a broken ore body using the uphole drift fill mining method

Abstract

The application provides a ventilation method for mining a broken ore body by using an up-to-inlet route filling mining method, wherein a steel air duct of a centralized return air roadway is arranged at a position close to a two-step route in a one-step route, a layer-by-layer welding of a layer-raising steel air duct is performed in the one-step route, ventilation of the one-step route is realized through an upper opening of the steel air duct, ventilation of the two-step route is realized through a two-step route ventilation opening in a side surface of the layer-raising steel air duct, and air volume adjustment is realized by adjusting an auxiliary fan, an adjusting plate and a side cover plate according to a value monitored by a wind speed sensor, so that the problem of one-step route dead-end ventilation is solved, the ore pillar is stable, the welding workload of the iron bucket is reduced, the material consumption and the electric energy consumption are reduced, the fallen stones in the steel air duct are cleaned, and the on-demand air supply of the stope is realized.

Description

Technical Field

[0001] This invention mainly relates to the field of mine ventilation safety, specifically a ventilation method for mining fractured ore bodies using the upward-passing backfilling mining method. Background Technology

[0002] When applying the upward-entry backfilling mining method in a fractured ore body, the construction of the riser in the approach is difficult or even impossible due to the fracture of the hanging wall ore body. The approach stope is a single-ended stop, and blasting fumes and heat accumulate, resulting in a harsh working environment for workers.

[0003] Currently, there are two traditional ventilation methods. One is to force ventilation by installing local fans and ventilation ducts at the entrance and connecting roadway. However, the ventilation cross-section is large, the exhaust speed of polluted air is limited, and the exhaust polluted air pollutes the external main roadway, causing secondary pollution. The other is to set up underground shafts in each entrance. However, if the shafts are set up too densely, it will easily cause the mine pillar to become unstable. The welding of iron drums is a lot of work and consumes a lot of materials. At the same time, there is no air volume adjustment device, so it is impossible to achieve flexible air distribution. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a ventilation method for mining fractured ore bodies using the upward-entry backfilling mining method. This invention involves installing a steel ventilation duct connecting to the lower centralized return airway at a location close to the second-step entry roadway in the first-step entry roadway. Layered lifting steel ventilation ducts are welded into the first-step entry roadway. Ventilation for the first-step entry roadway is achieved through the upper opening of the steel ventilation ducts, while ventilation for the second-step entry roadway is achieved through ventilation openings on the sides of the lifting steel ventilation ducts. Simultaneously, based on the values ​​monitored by the wind speed sensor, the airflow can be adjusted by regulating the auxiliary fan, regulating plate, and side cover plate. This solves the problem of single-ended ventilation in the entry roadway, promotes pillar stability, reduces the workload of welding iron drums, lowers material and energy consumption, facilitates the cleaning of fallen rocks from the steel ventilation ducts, and enables on-demand ventilation in the stope.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A ventilation method for mining fractured ore bodies using the upward-passing backfilling mining method includes a central horizontal return airway, a connecting roadway between the upper and middle sections of the return airway, a central return airway in the middle section, auxiliary fans, ventilation walls, installation shafts, steel ventilation ducts, and ventilation doors. The method is characterized in that: the central horizontal return airway is excavated from the main horizontal roadway along a direction perpendicular to the ore body strike to the designed position in the upper middle part of the ore body, and then, along the ore body strike, vein-side roadways are constructed on both sides until the panel boundary is reached. On one side, cross-vein excavation is carried out to the footwall position of the ore body. All central horizontal return airways in the middle section have an upslope of 3°-5°. The central return airway in the middle section has a slope of 45°-70°. The central return airway in the middle section is constructed to the top elevation of the upper and middle horizontal return airway. The connecting roadway between the upper and middle section of the return airway is the upper and middle horizontal return airway. The auxiliary fan is installed near the lower plate of the central return air shaft on one side of the central horizontal return airway. The auxiliary fan is selected based on the ventilation requirements of the panel area. The auxiliary fan is a variable frequency fan. The air wall is a concrete wall that assists in sealing the auxiliary fan. The installation shaft is located in the first step at the junction of the first and second steps. The installation shaft is close to the upper plate of the central horizontal return airway along the channel. The installation shaft is constructed vertically from the central horizontal return airway to the first layer bottom plate elevation of the first step. The first section of the steel air duct is welded together from a vertical section and an inclined section. The first section of the steel air duct is placed in the installation shaft and fixed with concrete. The air door is a series of two normally closed air doors that open towards the horizontal main roadway.

[0007] The lower ends of the first section of steel ventilation duct are welded with sliding grooves on both sides, and the adjustment plate is welded with a push-pull handle on one side. The adjustment plate can move freely on the sliding groove by operating the push-pull handle. The protective net cover is a metal mesh that can be fitted onto the upper opening of the first section of steel ventilation duct and the upper layer steel ventilation duct. When there is gravel falling in the upper mining area, the adjustment plate is pulled to the outside of the lower opening of the first section of steel ventilation duct.

[0008] The riser steel ventilation duct is welded to the previous section of the steel duct before each layer is filled, starting from the second layer of the first-step mining area. The vertical rise of the riser steel ventilation duct is equal to the designed filling height of each layer. The inclination angle of the riser steel ventilation duct is consistent with the dip angle of the ore body. A second-step ventilation opening is provided on the lower side of the riser steel ventilation duct adjacent to the second-step mining area. The second-step ventilation opening is welded with wire mesh. There is a sealed magnetic strip with a sealing ring around the four edges of the side cover plate. The side cover plate is strongly adsorbed onto the second-step ventilation opening to prevent tailings leakage during filling.

[0009] The side cover plate is removed during the second-step approach mining to achieve access ventilation. The second-step approach ventilation opening is not treated during the first layer filling of the second-step approach. After the next layer mining is completed, the second-step approach ventilation opening near the bottom plate is resealed with the side cover plate, and the side cover plate on the second-step approach ventilation opening near the top plate is removed.

[0010] The wind speed sensor is installed in the access road to measure the ventilation volume of the access mining area. When the wind speed sensor reading exceeds the normal range, the air volume can be adjusted by adjusting the auxiliary fan, the adjustment plate and the side cover plate.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] This invention solves the problem of single-ended ventilation in the access roadway by setting up a steel ventilation duct in the first-step access roadway, close to the second-step access roadway. Layer by layer, the steel ventilation ducts are welded into the first-step access roadway. Ventilation for the first-step access roadway is achieved through the upper opening of the steel ventilation ducts, while ventilation for the second-step access roadway is achieved through the ventilation openings on the sides of the raised-layer steel ventilation ducts. Simultaneously, based on the values ​​monitored by the wind speed sensor, the airflow can be adjusted by adjusting the auxiliary fan, regulating plate, and side cover plate. This solves the problem of single-ended ventilation in the access roadway, is beneficial to the stability of the mine pillar, reduces the amount of welding work on the iron drum, lowers material and energy consumption, facilitates the cleaning of fallen rocks from the steel ventilation ducts, and enables on-demand air supply to the mining area. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the method of the present invention;

[0014] Figure 2 This is a schematic diagram of the method of the present invention;

[0015] Figure 3 yes Figure 1 A magnified view of part I;

[0016] Figure 4 yes Figure 2 A magnified view of part II;

[0017] Figure 5 yes Figure 2 A magnified view of a portion of section III;

[0018] The following are the labels shown in the diagram: 1. Centralized return airway in the middle section; 2. Connecting passage between the upper and middle section return air shafts; 3. Centralized return air shaft in the middle section; 4. Auxiliary fan; 5. Air wall; 6. Installation shaft; 7. Steel air duct; 8. Slide groove; 9. Adjusting plate; 10. Push-pull handle; 11. Protective net cover; 12. Upward-floor steel air duct; 13. Two-step access ventilation opening; 14. Side cover plate; 15. Sealed magnetic strip; 16. Air door; 17. Wind speed sensor.

[0019] a. Main fracture surface of ore body; b. Footwall boundary of ore body; c. Ore body; d. Connecting roadway to the access stope; e. Sectional roadway; f. Horizontal main roadway; g. Upper and middle level horizontal return airway; h. First-step access stope; i. Second-step access stope; j. Ore chute. Detailed Implementation

[0020] The present invention will be further described in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0021] like Figure 1-5 As shown, this includes the central horizontal return airway 1, the connecting passage between the upper and middle section return air shafts 2, the central return air shaft 3, auxiliary fan 4, air wall 5, installation shaft 6, steel ventilation duct 7, and air door 16. The central horizontal return airway 1 is excavated from the main horizontal roadway along the direction perpendicular to the ore body strike to the designed position in the upper middle part of the ore body. Then, along the ore body strike, it is constructed along both sides of the vein roadway until the panel boundary. On one side, it is excavated through the vein to the footwall position of the ore body. All central horizontal return airways 1 have a 3° uphill slope. The central return air shaft 3 has dimensions of 2.0m x 2.0m and a slope of 60°. The central return air shaft 3 is constructed to the top elevation of the upper and middle section horizontal return airway. The connecting passage between the upper and middle section return air shafts 2 is the connecting passage between the upper and middle section horizontal return airway and the central return air shaft 3. The auxiliary fan 4 is installed... Near the lower plate of the central return airway 1 in this middle section, the auxiliary fan 4 is selected based on the ventilation requirements of the panel area. The auxiliary fan 4 is a variable frequency fan. The air wall 5 is a concrete wall that helps to seal the auxiliary fan 4. The installation well 6 has a size of 1.5m*1.5m. The installation well 6 is located in the first step of the roadway at the junction of the first and second steps. The installation well 6 is close to the upper plate of the central return airway 1 in this middle section along the channel. The installation well 6 is constructed vertically from the central return airway 1 to the first layer bottom plate elevation of the first step. The first section of steel ventilation duct 7 has a size of 1.0m*1.0m. The first section of steel ventilation duct 7 is welded into one piece by vertical and inclined sections. The first section of steel ventilation duct 7 is placed in the installation well 6 and fixed with concrete. The air door 16 is a normally closed air door that opens continuously towards the horizontal main roadway.

[0022] Specifically, sliding grooves 8 are welded to both sides of the lower end of the first section of steel ventilation duct 7. The length of the sliding grooves 8 is 2.0m. A push-pull handle 10 is welded to one side of the adjusting plate 9. By operating the push-pull handle 10, the adjusting plate 9 can move freely on the sliding grooves 8. The protective net cover 11 is a metal mesh that can be fitted onto the upper opening of the first section of steel ventilation duct and the rising layer steel ventilation duct 12. The mesh size of the protective net cover 11 is 0.2m*0.2m. When there is gravel falling in the upper mining area, the adjusting plate 9 is pulled out to the lower opening of the first section of steel ventilation duct 7.

[0023] Specifically, the rising steel ventilation duct 12 is welded to the previous section of the steel duct before each layer is filled, starting from the second layer of the first-step mining area. The vertical rise of the rising steel ventilation duct 12 is equal to the designed filling height of each layer. The inclination angle of the rising steel ventilation duct 12 is consistent with the dip angle of the ore body. A second-step ventilation opening 13 is provided on the lower side of the rising steel ventilation duct 12, adjacent to the second-step mining area. The second-step ventilation opening 13 has a specification of 0.6m*0.6m and is welded with a steel wire mesh with a specification of 0.2m*0.2m. The side cover plate 14 is a high-strength flat steel side cover plate with a specification of 0.9m*0.9m. There is a sealed magnetic strip 15 with a sealing ring 0.05m inward around the four edges of the side cover plate 14. The side cover plate 14 is strongly adsorbed on the second-step ventilation opening 13 to prevent tailings leakage during filling.

[0024] Specifically, the side cover plate 14 is removed from the second-step approach ventilation opening 13 during the second-step approach mining to achieve approach ventilation. The second-step approach ventilation opening 13 is not treated during the first layer filling of the second-step approach. After the next layer mining is completed, the second-step approach ventilation opening 13 near the bottom plate is sealed again with the side cover plate 14, and the side cover plate 14 on the second-step approach ventilation opening 13 near the top plate is removed.

[0025] Specifically, the wind speed sensor 17 is installed in the access road to measure the ventilation volume of the access mining area. When the value measured by the wind speed sensor 17 exceeds the normal range, the air volume can be adjusted by adjusting the auxiliary fan 4, the adjusting plate 10 and the side cover plate 14.

[0026] Example:

[0027] In a certain mine, the No. 1 mining area in the -796m section is mined using the upward-entry backfilling mining method. The average thickness of the ore body is 50m, the width of the mining area is 120m, and the dip angle of the ore body is 55°. The hanging wall ore body is broken and cannot be used to construct a raise, while the footwall surrounding rock is stable.

[0028] When using this method, the first step is to design the upward-entry filling mining method based on the ore body conditions of the mining area. The first-stage approach is 7m wide, and the second-stage approach is 8m wide. After the first-stage approach reaches three sections, the second-stage approach is constructed sequentially. After the first-stage approach is completed and the bottom excavation is finished, the central horizontal return airway 1 is constructed perpendicular to the ore body strike from the main horizontal roadway where the ore body is narrower. The central horizontal return airway 1 has a 3m x 3m diameter, a three-centered arch shape, and a 3° slope. Construction continues until 20m from the upper boundary of the ore body, then along the ore body strike on both sides of the vein. After the left vein is constructed to the mining area boundary, 50m of excavation is carried out towards the lower footing. Construction begins from the lower footing head. Section 3, a centralized return air shaft, has a slope of 60° and dimensions of 2m x 2m. The construction elevation reaches the top slab elevation of the -736m horizontal main roadway. A 70m connecting passage 2 for the upper and middle section return air shafts is constructed in the -736m horizontal main roadway, with dimensions of 3m x 3m. Installation shaft 6, 1.5m x 1.5m in size, is constructed in the first-step roadway at the junction of the first and second-step roadways, connecting to the bottom slab of the first-step roadway. A total of 8 shafts are required. A pre-fabricated first-section steel ventilation duct 7, 1.0m x 1.0m in size, is placed in each installation shaft 6. The first-section steel ventilation duct 7 is composed of a vertical section and an inclined section welded together, with the inclined section at 55° and a length of 3m. The joint between the first-section steel ventilation duct 7 and the installation shaft 6 is filled with concrete. The auxiliary fan 4 is installed in the lower plate of the -796m horizontal channel, with a power of 55kW and adjustable frequency. A concrete wall 5 is constructed on the outside of the auxiliary fan 4. Two consecutive normally closed air doors 16 are erected in the middle section of the horizontal centralized return airway 1 near the -796m main roadway, opening towards the horizontal main roadway. An air volume regulating device consisting of a slide 8, an adjusting plate 9, and a push-pull handle 10 is fabricated below the first section of steel air duct 7. A lifting layer steel air duct 12 is fabricated with a specification of 1.0m*1.0m and a length of 3m, with an installation inclination angle of 55°. Starting from the second layer of the first-step approach mining area, the lifting layer steel air duct 12 is connected before each layer is filled, and a protective net cover 11 with a mesh size of 0 is fitted on the upper opening. A 2m*0.2m steel ventilation duct 12 is provided on the lower side of the second-step access road, with a ventilation opening 13 of 0.6m*0.6m in size and welded with a wire mesh of 0.2m*0.2m in size. The side cover plate 14 is 0.9m*0.9m in size, with a sealed magnetic strip 15 with a sealing ring 0.05m inward from the four edges, which can strongly adhere to the second-step access road ventilation opening 13. The second-step access road ventilation opening 13 is not treated when the first layer of the second-step access road is filled. After the next layer of mining is completed, the second-step access road ventilation opening 13 near the bottom plate is sealed again with the side cover plate 14, and the side cover plate 14 on the second-step access road ventilation opening 13 near the top plate is opened.

[0029] The ventilation route for the first-step approach mining is as follows: intake shaft—transport roadway and ramp—section roadway—connecting roadway—entry mining area—steel ventilation duct (12 and 7)—central horizontal return airway 1—central return airway 3—upper-middle return airway connecting roadway 2—-736m horizontal return airway—central return airway—main return airway—main return airway—surface.

[0030] The ventilation route for the two-step approach is as follows: intake shaft—transport roadway and ramp—section roadway—connecting roadway—entry mining area—two-step approach ventilation opening 13—steel ventilation duct (12 and 7)—central horizontal return airway 1—central return airway 3—upper-middle return airway connecting roadway 2—-736m horizontal return airway—central return airway—main return airway—main return airway—surface.

[0031] Airflow control measures: Install wind speed sensor 17 in each intake. When the measured value exceeds the normal range, the airflow can be adjusted by adjusting the auxiliary fan 4, the regulating plate 10 and the side cover plate 14.

Claims

1. A ventilation method for mining fractured ore bodies using the upward-entry backfilling mining method, comprising a central horizontal return airway (1), an upper-middle return air shaft connecting roadway (2), a central return air shaft (3), an auxiliary fan (4), a ventilation wall (5), an installation shaft (6), a first-section steel ventilation duct (7), a chute (8), an adjusting plate (9), a push-pull handle (10), a protective net cover (11), a rising-layer steel ventilation duct (12), a two-step entry ventilation opening (13), a side cover plate (14), a sealed magnetic strip (15), and a ventilation door (16), characterized in that: The central horizontal return airway (1) of this section is excavated from the main horizontal roadway along the direction perpendicular to the ore body strike to the designed position in the upper middle part of the ore body. Then, along the ore body strike, the vein roadway is constructed on both sides until the boundary of the panel. On one side, the vein is excavated to the footwall position of the ore body. The central horizontal return airway (1) of this section has an upslope of 3°-5°. The slope of the central return air shaft (3) of this section is 45°-70° and is constructed to the top elevation of the upper central horizontal return airway. The connecting roadway (2) of the upper central return air shaft is the connecting channel between the upper central horizontal return airway and the central central return air shaft (3). The auxiliary fan (4) is installed near the vein in the footwall on one side of the central horizontal return airway (1). The selection of the auxiliary fan (4) The ventilation requirements of the panel area are calculated, and the auxiliary fan (4) is a variable frequency fan; the air wall (5) is a concrete wall that helps to seal the auxiliary fan (4); the installation well (6) is located in the first step of the roadway at the junction of the first step roadway and the second step roadway, and is close to the upper plate direction of the horizontal centralized return airway (1) of the middle section. The installation well (6) is constructed vertically from the horizontal centralized return airway (1) of the middle section to the first layer bottom plate elevation of the first step roadway; the first section of steel air duct (7) is welded into one piece by a vertical section and an inclined section. The first section of steel air duct (7) is placed in the installation well (6) and fixed with concrete pouring; the air door (16) is a continuous two normally closed air door that opens towards the horizontal main roadway. The lower ends of the first section steel ventilation duct (7) are welded with the sliding grooves (8) on both sides, and the adjustment plate (9) is welded with the push-pull handle (10) on one side. By operating the push-pull handle (10), the adjustment plate (9) can move freely on the sliding grooves (8). The protective net cover (11) is a metal mesh that is adapted to the upper opening of the first section steel ventilation duct (7) and the rising layer steel ventilation duct (12) and is used to be fitted on the upper opening of the first section steel ventilation duct (7) or the rising layer steel ventilation duct (12). When there is gravel falling in the upper mining area, the adjustment plate (9) is pulled completely outside the lower opening of the first section steel ventilation duct (7). Starting from the second layer of the first-step mining area, the rising steel ventilation duct (12) is welded to the previous steel ventilation duct before each layer is filled; the vertical rise of the rising steel ventilation duct (12) is equal to the designed filling height of each layer, and its inclination angle is consistent with the dip angle of the ore body; the rising steel ventilation duct (12) has a second-step ventilation opening (13) on the side of the lower side of the duct that is close to the second-step mining area, and the second-step ventilation opening (13) is welded with wire mesh; the four edges of the side cover plate (14) are provided with a ring of sealed magnetic strips (15) with sealing rings, and the side cover plate (14) is strongly adsorbed on the second-step ventilation opening (13) to prevent tailings leakage during filling; During the two-step approach mining, the side cover plate (14) is removed from the two-step approach ventilation opening (13) to achieve approach ventilation; the two-step approach ventilation opening (13) is not treated during the first layer filling of the two-step approach. After the next layer mining is completed, the two-step approach ventilation opening (13) near the bottom plate is sealed again with the side cover plate (14), and the side cover plate (14) on the two-step approach ventilation opening (13) near the top plate is removed.

2. The ventilation method for mining fractured ore bodies using the upward-pass backfilling mining method according to claim 1, characterized in that: The wind speed sensor (17) is installed in the access road and is used to measure the ventilation volume of the access mining area. When the measured value of the wind speed sensor (17) exceeds the normal range, the air volume is adjusted by adjusting the auxiliary fan (4), the adjustment plate (9) and the side cover plate (14).

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