CN111456736A - Method for maintaining stability of downward single-access filling false roof and recovering studs - Google Patents
Method for maintaining stability of downward single-access filling false roof and recovering studs Download PDFInfo
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- CN111456736A CN111456736A CN202010302504.4A CN202010302504A CN111456736A CN 111456736 A CN111456736 A CN 111456736A CN 202010302504 A CN202010302504 A CN 202010302504A CN 111456736 A CN111456736 A CN 111456736A
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- filling
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- chamber
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- false roof
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/22—Methods of underground mining; Layouts therefor for ores, e.g. mining placers
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F15/00—Methods or devices for placing filling-up materials in underground workings
Abstract
The invention discloses a method for maintaining stability of a downward single access filling false roof and recovering studs, and relates to the technical field of mining engineering. The method comprises the following steps: firstly, recovering the studs on two sides of the chamber, after the studs in the layers are exploited, immediately constructing ultralong prestressed anchor rods on the upper and lower plate surrounding rocks in a way of being vertical to the trend of the ore body, and welding and fixing exposed ends of the ultralong prestressed anchor rods through reinforcing steel bars; then carrying out cemented filling in the stud goaf, stoping the ore body in the chamber by adopting a downward drift layered non-segmented roadway filling mining method after the filling body is stable, constructing ultra-long anchor rods on the filling body at two sides of the drift after stoping of the chamber in the layered chamber is finished, and welding and fixing the exposed ends of the ultra-long anchor rods with the reinforcing steel meshes in the chamber; and finally, performing differential filling on the layered goaf. And repeating the steps until all the layers in the stope are mined. The method can not only recover the studs on two sides of the stope, but also form an embedded beam structure for filling the false roof by replacing the filling bodies of the studs, thereby improving the resource recovery rate and ensuring the stability of the false roof.
Description
Technical Field
The invention relates to the technical field of mining engineering, in particular to a method for maintaining stability of a downward single access filling false roof and recovering studs.
Background
The downward drift layered filling mining method is suitable for mining ore bodies which are extremely unstable and have high value, particularly when the thickness of the ore bodies is less than 20m, the drift is arranged along the trend; when the thickness of the ore body is more than 20m, the access way is arranged in a vertical direction. In order to ensure that each layered filling false roof in the stope keeps self stability without collapse, a reinforcing mesh is paved in the filling false roof in advance, and an ultra-long anchor rod with a certain row spacing is driven into two adjacent studs. The reinforcing mesh and the overlong anchor rod are firmly welded, so that the overlaying filling false roof is always in an embedded beam type structure in the lower layered mining process, and the stability of the overlaying filling top plate on a single access is ensured. In the prior art, patent document (CN103628878B) discloses a downward access layered non-sublevel roadway filling mining method, which realizes mining of inclined thin ore bodies. However, the method mainly depends on the studs on two sides to maintain the stability of the filling false roof of each layer of the stope, so that ore bodies in the studs cannot be recovered, and the loss of ore amount is large. Therefore, the existing downward access layered non-sublevel roadway filling mining method needs to be improved, and the recovery of the studs is realized under the condition of maintaining the stability of the downward single access filling false roof.
Disclosure of Invention
In order to recover the studs on two sides of a stope, ensure the stability of filling the false roof on a downward single access, realize high-efficiency mining and improve the recovery rate of ores, the invention provides a method for maintaining the stability of filling the false roof on the downward single access and recovering the studs, and the specific technical scheme is as follows.
A method for maintaining stability of a downward single-access filling false roof and recovering studs comprises the following specific steps:
step 1, recovering the studs on two sides of the chamber, and after the studs in the layers are mined, constructing ultralong prestressed anchor rods on the upper and lower surrounding rocks immediately perpendicular to the trend of the ore body, wherein the exposed ends of the ultralong prestressed anchor rods are welded and fixed through reinforcing steel bars;
step 3, after the stoping of the chamber in the stratified is finished, constructing ultra-long anchor rods on filling bodies on two sides of the access road of the chamber, and welding and fixing exposed ends of the ultra-long anchor rods and a reinforcing mesh in the chamber;
repeating the steps 1-4 until all layers in the stope are mined.
Preferably, the overlong prestressed anchor rod is a splicing type grouting anchor rod, and the total length of the splicing type grouting anchor rod is 4-8 m.
Preferably, during the extraction of the stud, the ore chute, the chute connecting channel, the pedestrian ventilation patio, the vein-penetrating air inlet channel, the vein-penetrating transportation channel, the cutting drift and the ore loading approach are all arranged on the lower wall of the ore body.
It is also preferable that after the extraction of the stud is completed, a filling-return air shaft is arranged to be connected with the vein-following return air lane, and the vein-following return air lane is communicated with the stope through the reserved filling-return air shaft.
It is also preferable that the reinforcing mesh in the chamber is provided with longitudinal bars, the reinforcing mesh is laid in the goaf and then hung on the reserved reinforcing hooks of the upper layer through the longitudinal bars, and the lower ends of the reinforcing hooks are firmly welded with the horizontal reinforcing bars at the bottom of the upper layer.
It is also preferred that the early-setting admixture be added to the fill material during both cement filling and differential filling.
The method for maintaining the stability of the downward single access filling false roof and recovering the studs provided by the invention has the beneficial effects that:
(1) according to the method, the stud is firstly mined and then filled in a cemented filling mode, so that the recovery rate of ores is greatly improved by the recovered stud, the loss and dilution are reduced, and the economic benefit can be increased; the filling dummy roof is in an embedded beam type stress state by using the overlong anchor rod to be driven into the filling body after the stud is replaced, so that the stability of each layered filling dummy roof is ensured, and the recovery safety is ensured.
(2) After the stoping of the chamber is finished, the overlength anchor rods are arranged on the two sides of the access road, and the anchor rods do not need to be arranged in the upper and lower surrounding rocks which run vertically to maintain the stability of the filling false roof, so that the construction process is simplified, and the production cost is reduced.
The method also has the advantages of simple and convenient construction, flexible mining, simple process, safety, high efficiency and the like.
Drawings
FIG. 1 is a top plan view of a stud and a chamber after filling;
FIG. 2 is a schematic cross-sectional view of a packed false roof and interval pillar production;
in the figure: 1-reinforcing mesh, 2-ultralong anchor rods, 3-filling layers, 4-ultralong prestressed anchor rods, 5-reinforcing steel bars, 6-adjacent chambers, 7-filling bodies, 8-studs, 9-chambers and 10-bearing layers.
Detailed Description
An embodiment of the method for maintaining the stability of the filling of the false roof to the single downward access and recovering the studs according to the present invention will be described with reference to fig. 1 to 2.
In the existing filling mining method for the downward access layered non-segmented roadway, in order to ensure that each layered overlying filling false roof in a stope keeps self stability and does not collapse, a reinforcing mesh needs to be laid in the filling false roof in advance, and an ultra-long anchor rod with a certain spacing row spacing is arranged in two adjacent columns, wherein the length of the stope is 40m, the ultra-long anchor rod is about 7m, and the reinforcing mesh and the ultra-long anchor rod are welded firmly, so that the overlying filling false roof is always in an embedded beam type structure in the process of lower layered mining, and the stability of the overlying filling roof of a single access is ensured. When the method is adopted, ore bodies in the studs cannot be recovered, and the method depends on the studs on two sides to maintain the stability of filling the false roof in each layer of the stope, so that the ore loss is large. To reduce the mining loss of the compartment column, a method of maintaining the stability of a single downward path filling false roof and recovering the compartment column is provided.
Example 1
A method for maintaining the stability of filling a false roof downward to a single access and recovering studs, which can recover studs and maintain the stability of filling the false roof downward to the single access. Firstly, mining ore bodies in two adjacent studs of the ore room, and then driving overlength prestressed anchor rods with a certain row spacing into the upper and lower tray surrounding rocks in the studs in a manner of being perpendicular to the direction of the ore bodies. The exposed end of the long anchor rod is firmly welded with the reinforcing mesh by paving the reinforcing mesh in the stud. The layered studs are subsequently cemented. By the method, the replacement stud filling body, the reinforcing mesh, the overlong anchor rod and the filling false roof in the chamber can form a whole, so that the filling body of the replacement stud ore body is always in a stable state. When the stoping and filling of the pillars on the two sides of the stope are finished, the layered stoping of the ore body in the stope is started from top to bottom, and each layer is about 3 m. After the mining of each layered ore body is finished, the filling body after the stud replacement is driven into the ultra-long anchor rods with a certain row spacing, the reinforcing mesh is laid in the inlet, and then the exposed ends of the ultra-long anchor rods are firmly welded with the reinforcing mesh. After construction, differential filling is carried out in the layered access road, in order to save cost, a bearing layer and a filling layer are respectively arranged, wherein the bearing layer has higher strength and higher cement content, and can bear overlying uniformly distributed loads, the overlying uniformly distributed loads comprise two parts, namely the gravity of a filling body and initial ground pressure, and the general compressive strength is more than 4 MPa. When the next layered ore body is mined, the overlying filling false roof is always in an 'embedded beam' type stress state, so that the stability of the filling false roof is ensured, and the whole collapse or slippage is avoided.
The downward single-route stoping refers to that when the thickness of an ore body is thin, only one route is arranged in the same layer in a stope, and stoping of the upper-layer route and stoping of the lower layer are directly carried out after filling is finished, so that the upper-layer route and the lower-layer route are necessarily arranged in parallel.
The method for maintaining the stability of the downward single access filling false roof and recovering the studs comprises the following specific steps:
step 1, firstly, the studs on two sides of the chamber are recovered, after the studs in the layers are mined, the overlength prestressed anchor rods are constructed on the upper and lower surrounding rocks immediately and vertically to the direction of the ore body, and the exposed ends of the overlength prestressed anchor rods are welded and fixed through reinforcing steel bars.
Because the size of the roadway section is limited, the ultra-long anchor rod needs to adapt to the size of the roadway section. Therefore, the overlong prestressed anchor rod is a splicing type prestressed grouting anchor rod, the total length of the splicing type grouting anchor rod is 4-8m, and can also be 5m or 7m, and prestress needs to be applied to the surrounding rock in the installation process of the overlong prestressed anchor rod, so that the surrounding rock is in a compression state rather than a tension state, and the stability of the surrounding rock is improved. And grouting after installation to ensure that the surrounding rocks of the upper and lower plates are firmly bonded with the anchor rod. Before the extraction of the stud, the mining preparation and the cutting roadway are uniformly arranged on the lower wall of the ore body and comprise an ore chute, a chute connecting channel, a pedestrian ventilation patio, a vein-through air inlet channel, a vein-through transportation channel, a cutting drift and an ore loading route. The pedestrian ventilation raise is arranged at a position 2m away from a lower plate contact zone in the center of the ore body, and an ore pass and a pass connecting channel are tunneled at the position, close to the ore body, in the center of the lower plate; and the stoping work is carried out from top to bottom, a cutting gallery is tunneled to the ore body by a pedestrian ventilation raise during stoping, and a stoping access is arranged in the cutting gallery.
And 2, filling the goaf of the stud in a cemented filling mode, and stoping the ore body by adopting a downward access layered non-sublevel roadway filling mining method after the filling body is stable. And after the extraction of the stud is finished, arranging a filling-air return shaft to be connected with the vein-following air return roadway, wherein the vein-following air return roadway is communicated with the stope through the reserved filling-air return shaft.
And 3, after the stoping of the chamber in the stratified is finished, constructing the overlength anchor rods on the filling bodies on the two sides of the access road of the chamber, and welding and fixing the exposed ends of the overlength anchor rods and the reinforcing mesh in the chamber.
The reinforcing steel bar net in the chamber is provided with longitudinal bars, the reinforcing steel bar net is laid in a goaf and then hung on the reserved reinforcing steel bar hooks on the upper layer through the longitudinal bars, the lower end of the reinforcing steel bar net is firmly welded with the bottom reinforcing steel bar net to ensure that the artificial false roof cannot be greatly bent and sunk, and the overlength anchor rods are laid along two sides of an approach path instead of a vertical direction (namely, the upper and lower tray surrounding rocks) after the chamber is mined, so that the construction process is greatly simplified, the section size of the trend of the ore body is 3 × 40m, and the sections of two sides of the ore body are only 3 × 5m, so that the method improves the recovery efficiency and reduces the mining cost.
The embedded beam structure means that when the layered mining of an ore body is carried out, ultra-long anchor rods with certain row spacing are embedded into ore pillars (or filling bodies) on two sides, the other ends of the anchor rods are firmly welded with reinforcing mesh arranged in an artificial false roof (filling body), and the anchor rods embedded into the ore pillars (or filling bodies) are reinforced by grouting, so that the anchor rods-the ore pillars (filling bodies) on two sides-a filling top plate form a whole, and the structure can always ensure the stability of the overlying filling false roof.
Repeating the steps 1-4 until all layers in the stope are mined.
In the steps, the coagulant is added into the filling material in the process of cement filling and differential filling, so that the maintenance time is shortened, and the exploitation efficiency is improved.
Example 2
To further illustrate the beneficial effects of a method for maintaining the stability of a downward single-pass packed false roof and recovering studs, the actual mining of a certain gold mine is taken as an example for further explanation.
The geological data and mining technical conditions of a certain gold ore can be known, the ore body is 150-200 m away from the earth surface, the average thickness is 5.0m, and the average length of the ore body in a stope is 40m, the total length of the pillars at two sides of adjacent stopes is 15m (7.5 m each), the height is 50m, the inclination angle is about 75 degrees, the average grade of the ore is 3.98g/t, and the ore body is extremely crushed. The lithology of the ore is yellow iron sericite, and the phenomenon of natural collapse is serious; the ore body surrounding rock is sericite-petrolite granite, the ore body upper wall is extremely broken, the stability of the lower wall is general, the thickness is over 2m, the local collapse is serious, and the control cannot be realized. The coefficient of prev of the ore is 6-8, and the coefficient of prev of the rock is 4-6. Ore density: 2.68t/m3。
And (4) adopting a downward access layered non-sublevel roadway filling mining method to carry out stoping on ore bodies and adjacent studs in the stope. The height of each layer is 3m (the first mining layer is 2m), and the total number of the layers is 17. Only the cost required by mining accuracy, cutting, stoping workload, filling and mineral processing and the benefit of stoping the ore are calculated when the stoping studs are mined.
As shown in Table 1, the tunnel workload of exploiting, preparing and cutting the stud requires about 2573.6m3The cost is 500 yuan/m according to the contract3And calculating, and investment of 128.7 ten thousand RMB is needed.
TABLE 1 engineering scale for developing, cutting and mining roadway during pillar extraction
The filling cost comprises two parts of filling materials and a filling process. And filling by adopting a cementing filling mode, wherein the cementing material is 425# ordinary portland cement, the filling aggregate is tailing of the mine tailing warehouse and crushed stone conveyed out from the underground, and the filling water is underground pit wastewater. A mortar-to-sand ratio of 1:4 (assuming that each layered filling is entirely made up of bearing layers) was used, i.e. a cement content of 200kg/m3. The cost of the cement required by each cubic meter is 60 yuan calculated by 300 yuan per ton. Considering the material cost of tailings, broken stones, early strength agent and the like, the material cost is estimated to be 65 yuan/m3. The filling process comprises factors of ventilation, slurry preparation, transportation, equipment loss, power supply, water supply, drainage and the like, and the estimated cost is 30 yuan/m3. Links such as steel bar laying, construction of an ultra-long anchor rod and the like are considered, and the cost required by each cubic meter is estimated to be 50 yuan. Total 145 yuan/m3The volume of the pillars at two sides of the chamber is 7.5 × 2 × 5 × 50-3750 m3The cost required for filling is calculated to be about 54.4 ten thousand yuan.
If the beneficiation cost is calculated according to 50 yuan per ton, the beneficiation cost of one stud ore is about 50 × 10050 to 50.3 ten thousand yuan.
Therefore, the mining, cutting, filling and mineral separation cost of one stud totals 233.4 ten thousand yuan.
According to the market price of the produced gold: the ore amount of each compartment column can be mined according to 3750m3And calculating to obtain 39999 g of gold by calculating the weight of the ore to be 10050 tons, and realizing the total yield of 1480 ten thousand yuan by calculating according to the market price of 370 yuan/g of gold.
Therefore, by adopting the method, 10050 tons of more than the amount of the pillared ores can be recovered, the total profit amount is 1480-233.4-1246.6 ten thousand yuan, and the mine benefit is greatly improved.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.
Claims (6)
1. A method for maintaining stability of a downward single-access filling false roof and recovering studs is characterized by comprising the following specific steps:
step 1, recovering the studs on two sides of the chamber, and after the studs in the layers are mined, constructing ultralong prestressed anchor rods on the upper and lower surrounding rocks immediately perpendicular to the trend of the ore body, wherein the exposed ends of the ultralong prestressed anchor rods are welded and fixed through reinforcing steel bars;
step 2, filling the goaf of the stud in a cemented filling mode, and stoping ore bodies in the chamber by adopting a downward access layered non-segmented roadway filling mining method after the filling bodies are stable;
step 3, after the stoping of the chamber in the stratified is finished, constructing ultra-long anchor rods on filling bodies on two sides of the access road of the chamber, and welding and fixing exposed ends of the ultra-long anchor rods and a reinforcing mesh in the chamber;
step 4, performing differential filling on the goaf in the layered chamber, arranging a bearing layer at the position adjacent to the lower layer, and arranging a filling layer above the bearing layer;
repeating the steps 1-4 until all layers in the stope are mined.
2. The method for maintaining the stability of a downward single-access filling false roof and recovering studs according to claim 1, wherein the ultra-long prestressed anchor is a split grouting anchor, and the total length of the split grouting anchor is 4-8 m.
3. The method of claim 1, wherein the ore pass, pass connection, pedestrian ventilation patio, drift inlet, drift transport, cut gate and ore loading approach are all disposed on the footwall of the ore body during recovery of the compartment.
4. The method for maintaining the stability of the downward single-pass filling false roof and recovering the stud according to claim 3, wherein a filling-return air shaft is arranged to be connected with the vein-following return air shaft after the stud recovery is completed, and the vein-following return air shaft is communicated with the stope through the reserved filling-return air shaft.
5. The method for maintaining the stability of the downward single-access filling of the false roof and recovering the stud as claimed in claim 1, wherein the reinforcing mesh in the chamber is provided with longitudinal bars, the reinforcing mesh is laid in the goaf and then hung on the reserved reinforcing hooks of the upper layer through the longitudinal bars, and the lower ends of the reinforcing hooks are welded and fixed with the horizontal reinforcing bars at the bottom of the upper layer.
6. The method of maintaining false roof stability and recovering studs for a single access pack according to claim 1 wherein an early coagulant is added to the pack material during the cement pack and differential pack.
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Citations (5)
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|---|---|---|---|---|
| CN1162690A (en) * | 1996-04-12 | 1997-10-22 | 崔正洙 | Underground mining process |
| CN101737052A (en) * | 2009-12-28 | 2010-06-16 | 河北邯邢矿冶设计院有限公司 | Sublevel fill-mining method |
| CN101858217A (en) * | 2010-05-18 | 2010-10-13 | 中南大学 | House pillar changeable panel upward demix filling mining method |
| CN104727820A (en) * | 2015-04-07 | 2015-06-24 | 长沙有色冶金设计研究院有限公司 | Two-step sublevel open-stop and delayed filling mining method |
| CN109595016A (en) * | 2018-12-27 | 2019-04-09 | 中南大学 | False top construction method is exploited to admission passage filling under one kind |
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2020
- 2020-04-17 CN CN202010302504.4A patent/CN111456736B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1162690A (en) * | 1996-04-12 | 1997-10-22 | 崔正洙 | Underground mining process |
| CN101737052A (en) * | 2009-12-28 | 2010-06-16 | 河北邯邢矿冶设计院有限公司 | Sublevel fill-mining method |
| CN101858217A (en) * | 2010-05-18 | 2010-10-13 | 中南大学 | House pillar changeable panel upward demix filling mining method |
| CN104727820A (en) * | 2015-04-07 | 2015-06-24 | 长沙有色冶金设计研究院有限公司 | Two-step sublevel open-stop and delayed filling mining method |
| CN109595016A (en) * | 2018-12-27 | 2019-04-09 | 中南大学 | False top construction method is exploited to admission passage filling under one kind |
Non-Patent Citations (1)
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| 冯帆等: "浅埋下向单一进路巷道胶结充填顶板稳定性分析", 《采矿与安全工程学报》 * |
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