Room and pillar type phosphorite mining method for pre-filling and constructing continuous intermediate pillars

Abstract

The invention provides a room-and-pillar type phosphorite mining method for pre-filling and constructing continuous intermediate pillars, and belongs to the technical field of underground mine mining. The method mainly comprises the following steps: S1, advanced mining preparation: constructing a cutting uphill and a strip type roadway of a next to-be-mined ore block in advance while or before the current ore block is mined; s2, strip-type filling is conducted to construct a continuous interval column, continuous and dense concrete filling is conducted on a strip-type roadway at the specific position, a continuous concrete structural body is formed after hardening and serves as an ore block interval column, and the structural body synchronously replaces the functions of an ore top column and an ore bottom column needed by traditional mining; and S3, ore block stoping is conducted, specifically, stoping is conducted on the ore room according to a room-and-pillar method process in cooperation with a small number of reserved ore point columns under lateral and top and bottom plate supporting of the continuous concrete space columns. According to the method, the problem that the stability of ore pillars is poor under the deep high ground pressure condition is effectively solved through the mode of replacing pillars with filling, the hidden danger of roof collapse is eliminated, and meanwhile the recovery rate of phosphorite resources is remarkably increased.

Description

Technical Field

[0001] This invention relates to the field of mining, and in particular to a room-and-pillar phosphate mining method using pre-filled continuous pillars. Background Technology

[0002] Currently, phosphate mining is gradually moving towards deeper areas below the erosion base level. Although the traditional room and pillar mining process has the advantages of relatively simple technology and large production capacity, its drawbacks are becoming increasingly apparent under the complex conditions of high ground pressure at depth.

[0003] In the prior art, such as the prior art CN108708725B, a safe and efficient mining method for gently dipping ore bodies is disclosed. This method involves filling the goaf of a room-and-pillar stope with cemented tailings. After the filling body is formed, the pillars are recovered by inclined tunneling under the protection of the filling body.

[0004] For example, the existing technology CN103967493B discloses a pillar mining method for gently dipping thin ore bodies. This method also involves first filling the mined-out area with cementitious tailings sand, and then recovering the pillars from top to bottom. While these two existing technologies address the problem of residual pillar recovery to some extent, they are essentially secondary recovery processes involving "mining the stope first, then filling, and then recovering the pillars." This process is not only cumbersome with long filling and recovery cycles, but also highly susceptible to ground pressure damage during the initial mining phase in deep, high-stress environments, leading to stope instability. Furthermore, the cost of large-scale filling of the mined-out area before recovering the pillars is high, and the construction is difficult, making it difficult to fundamentally resolve the contradiction between overall stope stability and efficient one-time resource recovery in deep mining.

[0005] In existing technologies, ore pillars are easily damaged under extremely high geostress, leading to an imbalance in the original stress state of the mining area and stress redistribution, which often causes safety accidents such as roof deformation or even collapse. At the same time, in order to ensure the stability of the mining area, traditional methods must retain a large number of permanent ore pillars, bottom pillars and interstitial pillars, which results in a huge loss of mineral resources and makes it difficult to meet the needs of efficient mining. Summary of the Invention

[0006] The main objective of this invention is to provide a room-and-pillar method for mining phosphate mines by pre-filling and constructing continuous pillars. This method solves the safety hazards caused by insufficient stability of ore pillars under high ground pressure in the traditional room-and-pillar method for deep phosphate mining, as well as the technical problems of cumbersome pillar recovery processes and resource waste caused by the inability to extract resources efficiently in one go in the existing technology.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for room-and-pillar phosphate mining with pre-filled continuous pillars, the method comprising: S1. Advance mining preparation: While or before the current mining block is being mined, advance construction of the preparation roadway for the next block to be mined; the preparation roadway includes cutting uphill roadways arranged along the dip of the ore body and strip roadways arranged along the strike of the ore body. S2. Strip-type filling construction of continuous inter-block columns: The strip-type roadway at a specific location completed in step S1 is continuously and densely filled with concrete. After the filling body hardens, a continuous concrete structure is formed. The continuous concrete structure constitutes the inter-block columns and is used to support the top and bottom plates, simultaneously replacing the function of the top and bottom columns required by the block. S3. Block mining: After the inter-block pillars reach the design strength, the rooms formed by the inter-block pillars are mined according to the room-and-pillar mining process, under the lateral and top and bottom support provided by the inter-block pillars. No ore top pillars, bottom pillars and continuous inter-block pillars are reserved during the mining process.

[0008] In the preferred embodiment, the specific construction method for advance preparation in step S1 is as follows: Simultaneously, the construction of the inlet and connecting roadway was carried out, with a width of 4-4.5 meters. The completed roadway was supported by anchor bolts throughout. The connecting roadway is located on one side of the stope and is used to connect adjacent mining units.

[0009] In the preferred embodiment, step S1 further includes construction steps along the designed top column location: In the upper middle section, mining was arranged, and No. 1 and No. 7 bottom roadways were constructed from the cutting uphill to both sides respectively; The No. 1 and No. 7 roadways are 4-4.5 meters wide and are connected to the middle / segment roadways of the previous middle section to form a return air inlet and an emergency exit. Anchor bolt support was installed in the No. 1 and No. 7 bottom roadways.

[0010] In the preferred embodiment, before step S2, a step of processing the connecting tunnel is also included: The connecting tunnel is wet-filled to form an auxiliary support structure or isolation zone.

[0011] In the preferred scheme, the specific implementation target of "strip filling to construct continuous columns" in step S2 is the No. 7 bottom roadway: The No. 7 Ladi roadway is a strip-type roadway used to construct pillars between ore blocks; When the construction of the No. 1 bottom roadway is completed and the construction of the No. 2 bottom roadway is half completed, the No. 7 bottom roadway will be poured to form the inter-block pillar.

[0012] In the preferred scheme, the "mining of ore blocks" in step S3 proceeds according to the following time sequence: After the construction of No. 1 bottom roadway is completed, the construction of No. 2 bottom roadway is 50% complete, and the pouring of No. 7 bottom roadway is completed, the construction of No. 3 bottom roadway will begin. At the same time, back mining was carried out in the No. 1 bottom roadway area.

[0013] In the preferred scheme, during the mining process, as the bottom roadway is advanced step by step, point pillars are retained in the stope to provide support in conjunction with the pillars between the blocks; The point pillars are ore point pillars, with a size of not less than 4 meters × 4 meters, and the spacing between adjacent point pillars is set to 7-9 meters.

[0014] In the preferred embodiment, the ore block recovery process in step S3 also includes a safety protection step: Temporary wire mesh is used to enclose the mining area along the direction of the safety exit at the mining face to prevent loose rocks from falling or personnel from accidentally entering unsafe areas.

[0015] In the preferred embodiment, the mining operation in step S3 is carried out by mechanized operation, and the cutting uphill serves as a free face and transportation and ventilation channel during the mining period; During the mining process, the return air passage formed by the connection with the middle / segment roadway is used to create a waste air return air flow path.

[0016] In a preferred embodiment, the method further includes the step of: S4. Post-processing: Following steps S1 to S3, the mine is backed up to the bottom pillar (3) position. After the entire mine is backed up, the entrance to the cutting uphill (4) is sealed by pouring concrete to complete the mining cycle of the block.

[0017] This invention provides a method for room-and-pillar phosphate mining using pre-filled continuous pillars. The method involves constructing a pre-existing mining roadway and immediately backfilling it with strip concrete, creating a high-strength continuous concrete structure as permanent pillars before mining operations. This pre-filled continuous concrete pillar provides stronger and more uniform lateral and roof / floor support than traditional dispersed ore pillars, effectively addressing deep high-pressure environments and significantly enhancing the stability of the stope throughout the mining cycle, fundamentally eliminating the safety hazard of roof deformation and collapse. Simultaneously, this method achieves "replacing ore with concrete," using artificially constructed continuous structures to simultaneously replace the ore pillars, floor pillars, and pillars that must be reserved in traditional mining. This allows these high-value phosphate resources to be fully extracted in the initial mining stage without the need for complex secondary pillar recovery operations, greatly improving the resource recovery rate of the mine while ensuring mining safety. In addition, this technology optimizes the mining and filling process, organically combining the construction of support structures with mining operations. Through specific timing of bottom pulling and pouring, it achieves continuous and mechanized mining operations, significantly improving the mining efficiency of deep ore bodies. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the cutting of the uphill and connecting tunnels in this invention; Figure 2 This is a schematic diagram of the construction of the No. 1 bottom roadway and the filling of the connecting roadway of the present invention; Figure 3 This is a schematic diagram of the construction of the No. 2 bottom-pull tunnel and the pouring of the No. 7 bottom-pull tunnel of the present invention; Figure 4 This is a schematic diagram of the construction of the No. 3 bottom-pull tunnel of the present invention; Figure 5 This is a schematic diagram of the mining advancement in the middle of the stope and the ore pillar retention of the present invention; Figure 6 This is a schematic diagram illustrating the temporary wire mesh enclosure method used in this invention along the safety exit mining area; Figure 7 This is a schematic diagram of the construction of the No. 6 bottom haulage roadway at the bottom of the mine in this invention; Figure 8 This is a schematic diagram of the completion of mine stope mining and the closure of the cutting entrance to the hillside in this invention.

[0019] In the diagram: 1. Middle / segment roadway; 2. Top pillar; 3. Bottom pillar; 4. Cutting uphill; 5. Connecting roadway; 6. Inter-block pillar; 7. Point pillar; 8. Return air vent; 9. Dry backfill; 10. Temporary mesh enclosure. Detailed Implementation

[0020] Example 1 like Figure 1-8 As shown, a method for room-and-pillar phosphate mining with pre-filled continuous pillars is described, the method comprising: S1. Advance mining preparation: While or before the current mining block is being mined, advance construction of the preparation roadway for the next block to be mined; the preparation roadway includes the cutting uphill roadway 4 arranged along the dip of the ore body and the strip roadway arranged along the strike of the ore body. S2. Strip-type filling to construct continuous inter-column: The strip-type roadway at a specific location completed in step S1 is continuously and densely filled with concrete. After the filling body hardens, a continuous concrete structure is formed. The continuous concrete structure constitutes the inter-column 6 of the ore block and is used to support the top and bottom plates, simultaneously replacing the function of the top column 2 and bottom column 3 required by the ore block. S3. Mining of ore blocks: After the inter-block pillars 6 reach the design strength, the ore blocks formed by the inter-block pillars 6 are mined in accordance with the room-and-pillar mining process, under the lateral and top and bottom plate support provided by the inter-block pillars 6. No ore top pillars, bottom pillars and continuous inter-block pillars are reserved during the mining process.

[0021] Step S1 emphasizes constructing the cutting incline and strip tunnels for the next ore block simultaneously with or before the current block's mining, achieving advanced deployment of mining preparation work and providing a spatial foundation for subsequent backfilling. Step S2 proposes an innovative concept of replacing natural ore top and bottom pillars and inter-pillars with concrete backfill. By continuously and densely pouring concrete into tunnels at specific locations, an artificial continuous concrete structure is formed as a permanent support. This structure can actively bear ground pressure.

[0022] Step S3 clarifies that after the concrete structure reaches its strength, it will be used for mining, utilizing its lateral and roof / floor support, thus eliminating the need to retain the ore resources that were originally used for support. The beneficial effect of this technical solution is that by replacing low-strength ore pillars with pre-constructed high-strength artificial pillars, it significantly solves the problem of stope stability under high ground pressure in deep mining, eliminates the risk of roof collapse, and simultaneously replaces and mines out all the original necessary roof / floor pillars and pillars, greatly improving the recovery rate of phosphate ore resources.

[0023] In the preferred embodiment, the specific construction method for advance preparation in step S1 is as follows: Simultaneously, the construction of the inlet cutting 4 and the connecting roadway 5 was carried out. The width of the inlet cutting 4 and the connecting roadway 5 was 4-4.5 meters, and the completed roadway was supported by anchor bolts throughout. The connecting roadway 5 is located on one side of the stope and is used to connect adjacent mining units.

[0024] This step explicitly stipulates the simultaneous construction of the uphill and connecting roadways, with both widths controlled between 4 and 4.5 meters, and supported by bolts throughout. This width setting is designed to accommodate the operational space requirements of mechanized equipment such as medium-deep hole drilling rigs and loaders, while limiting the exposed area to maintain roadway stability and prevent stress concentration leading to deformation. Full-length bolt support ensures the long-term stability of the roadway before the filling material forms, avoiding maintenance challenges associated with premature construction. The connecting roadway, located on one side of the stope, not only serves as a passage connecting adjacent mining units but also lays the spatial foundation for the subsequent construction of a continuous artificial isolation zone, achieving an organic unity between roadway excavation and filling construction functions.

[0025] In the preferred embodiment, step S1 further includes a construction step along the designed top column 2 location: In the upper middle section, mining was arranged, and No. 1 and No. 7 bottom pull roadways were constructed on both sides of the cutting uphill section 4. The No. 1 and No. 7 roadways are 4-4.5 meters wide and are connected to the middle / segment roadway 1 of the previous middle section to form the return air inlet 8 and the emergency exit. Anchor bolt support was installed in the No. 1 and No. 7 bottom roadways.

[0026] During the mining layout of the upper section, No. 1 and No. 7 bottom-pull roadways were constructed from the cutting uphill direction on both sides, with widths also set at 4 to 4.5 meters. The key to this layout is to connect these bottom-pull roadways with the middle or segmental roadways of the upper section, thus directly forming return air inlets and emergency exits. The beneficial effects of this technique are that a complete wastewater ventilation and safety escape system is established in the early stages of mining. The negative pressure ventilation created by the connection project effectively improves the deep-well working environment, while clearly defining the left and right boundaries of the stope, providing a spatial benchmark for subsequent orderly mining.

[0027] In the preferred embodiment, before step S2, a processing step for the connecting lane 5 is also included: The connecting lane 5 was wet-filled to form an auxiliary support structure or isolation zone.

[0028] This step transforms the original empty roadway into a solid auxiliary support structure or isolation zone. Wet backfilling ensures the backfill material has good fluidity and roof support, forming a high-strength solid wall after hardening. Its beneficial effects include converting the connecting roadway into part of the artificial support structure, which not only isolates adjacent stopes but also enhances the overall bearing capacity of the area, preventing the impact of adjacent goaf and surrounding rock movement on the current working face, and ensuring the independence and safety of block mining.

[0029] In the preferred scheme, the specific implementation target of "strip filling to construct continuous columns" in step S2 is the No. 7 bottom roadway: The No. 7 Ladi roadway is a strip-type roadway used to construct the inter-block pillar 6; When the construction of the No. 1 bottom roadway is completed and the construction of the No. 2 bottom roadway is half completed, the No. 7 bottom roadway will be poured to form the inter-block pillar 6.

[0030] Specifically, the No. 7 bottom-level tunnel was poured after the construction of the No. 1 bottom-level tunnel was completed and the No. 2 bottom-level tunnel was halfway completed. The scientific basis of this timing design lies in utilizing the pre-reserved rock mass from the No. 2 bottom-level tunnel to temporarily support the roof, while simultaneously utilizing the space from the No. 1 bottom-level tunnel for operations. This ensures that the stress in the surrounding rock mass remains under control during the pouring of the No. 7 tunnel. Its beneficial effect is that it achieves parallel and overlapping operations of mining and backfilling, ensuring the timely construction of continuous inter-pillars while avoiding stress concentration caused by large-area overhangs, thus ensuring the safety of the backfilling operation and the integrity of the backfill material.

[0031] In the preferred scheme, the "mining of ore blocks" in step S3 proceeds according to the following time sequence: After the construction of No. 1 bottom roadway is completed, the construction of No. 2 bottom roadway is 50% complete, and the pouring of No. 7 bottom roadway is completed, the construction of No. 3 bottom roadway will begin. At the same time, back mining was carried out in the No. 1 bottom roadway area.

[0032] The timeline for mining block recovery was defined, stipulating that construction of the No. 3 bottom-reaching roadway and mining of the No. 1 bottom-reaching area would only commence after the completion of the No. 1 bottom-reaching stage, the completion of the No. 2 bottom-reaching stage, and the completion of the No. 7 bottom-reaching stage pouring. This stipulation aims to allow sufficient curing time for the concrete backfill and ensure that mining operations are always conducted within the protection range of an effective support system. Its beneficial effect lies in establishing a steadily advancing operational cycle, ensuring that before a new mining free face forms, the surrounding support structures, especially the artificial columns formed by the No. 7 bottom-reaching stage, have already acquired preliminary load-bearing or isolation capabilities, thereby significantly reducing the dynamic risks of deep mining.

[0033] In the preferred scheme, during the mining process, as the bottom roadway is advanced step by step, point pillars 7 are retained in the stope to provide support in conjunction with the inter-block pillars 6. Point column 7 is an ore point column with a size of not less than 4 meters × 4 meters, and the spacing between adjacent point columns 7 is set to 7-9 meters.

[0034] As the roadway advances, it is required that ore support pillars with dimensions no less than 4 meters by 4 meters and a spacing of 7 to 9 meters be maintained. These support pillars, together with the surrounding continuous concrete columns, form a point-line combined support system. The beneficial effect is that although most of the roof and floor pillars are replaced, support pillars are still needed inside the stope to control the local span of the roof and prevent localized roof collapses. The 4-meter by 4-meter dimensions and the 7- to 9-meter spacing are optimized parameters derived from rock mechanics calculations, which can meet the support requirements of deep ground pressure while minimizing ore loss, achieving an optimal balance between safety and resource recovery.

[0035] In the preferred embodiment, the ore block recovery process in step S3 also includes a safety protection step: Along the safety exit direction at the mining face, temporary wire mesh is used to enclose the mining area to prevent loose rocks from falling or personnel from accidentally entering unsafe areas.

[0036] Specific safety protection measures have been added, namely, temporary wire mesh enclosure along the safety exit direction of the mining face. Since cutting uphill or safety passages are often areas frequently traversed by personnel and equipment, loose rocks generated during mining operations can easily cause injury. The beneficial effect of this technical feature is that it establishes a flexible isolation barrier, effectively intercepting potentially falling loose rocks and preventing personnel from accidentally entering unsafe areas where work is underway or where the roof is unstable. This significantly improves the safety management level of the production site and embodies a people-oriented safety production philosophy.

[0037] In the preferred embodiment, the mining operation in step S3 is carried out by mechanized operation, and the cutting uphill 4 serves as the free face and transportation and ventilation channel during the mining period; During the mining process, the return air flow path is formed by the return air inlet 8 that is formed by the connection with the middle / segment roadway 1.

[0038] The design emphasizes mechanized operations and utilizes the cutting incline as a free face, transportation, and air intake channel, while exhausting polluted air through the return air vents formed by the through-flow. This setup clearly defines the mine's ventilation network and logistics path. Its benefits include shortening ore handling distances and improving the operational efficiency of trackless equipment such as loaders by using the cutting incline as a central hub; simultaneously, fresh air enters from the cutting incline, while polluted air is directly exhausted to the upper and middle section return airway through the return air vents, forming a complete through-flow system that effectively solves the problem of ventilation and heat dissipation difficulties in deep mining.

[0039] In a preferred embodiment, the method further includes the step of: S4. Post-processing: Following steps S1 to S3, the ore is back-mined to the position of the bottom pillar 3. After the entire ore mining operation is completed, the entrance to the cutting uphill section 4 is sealed by pouring concrete to complete the mining cycle of this block.

[0040] The regulations define the final steps of the mining cycle, namely S4 post-mining. After mining to the stope pillar position according to the established steps, the entrance to the cutting incline is sealed with concrete. This step marks the completion of a block's mining cycle. Its beneficial effects are that by sealing the cutting incline, the mined-out hazardous area is completely isolated from the production system, preventing the impact shockwaves from later-stage rockfalls in the goaf from harming other work areas. It also creates closed boundary conditions for the mining of adjacent blocks, achieving orderly succession of mine production and a closed loop for goaf management.

[0041] Example 2 To further illustrate with reference to Example 1, the present invention provides a method for room-and-pillar phosphate mining using pre-filled continuous pillars, such as... Figures 1 to 8 As shown, advance preparation is first carried out. Simultaneously with or before the current mining operation, the uphill section 4 and connecting roadway 5 are constructed. The roadway width is controlled at 4-4.5 meters, and the entire roadway is anchored. Connecting roadway 5, located on one side of the stope, is used for subsequent wet-cast filling to form a continuous concrete structure, namely the inter-block pillar 6. This structure will serve as a permanent inter-block pillar, simultaneously replacing the functions of the top pillar 2 and bottom pillar 3 required by the ore block.

[0042] Next, the bottom-pull and backfilling arrangements are carried out. Backfilling is arranged in the upper middle section along the designed top pillar 2 position. The No. 1 bottom-pull roadway is constructed from the cutting uphill section 4 to both sides. This roadway, marked as "Bottom-1" in the attached diagram, has a width of 4-4.5 meters and is connected to the middle / segment roadway 1 of the upper middle section, thus forming the return air inlet 8 and emergency exit. Simultaneously, the connecting roadway 5 is wet-filled. The backfilling operation follows a specific time sequence. When the construction of the No. 1 bottom-pull roadway is completed, the construction of the No. 2 bottom-pull roadway (shown in the diagram) begins. When the No. 2 bottom-pull roadway is halfway completed, the No. 7 bottom-pull roadway (shown in the diagram) is poured. When the construction of the No. 1 bottom-pull roadway is completed, the No. 2 bottom-pull roadway is 50% complete, and the No. 7 bottom-pull roadway pouring is finished, the construction of the No. 3 bottom-pull roadway (shown in the diagram) begins, and backfilling is simultaneously arranged in the No. 1 bottom-pull roadway.

[0043] Throughout the entire block mining process, the bottom-pull mining steps described above are followed sequentially until the stope bottom pillar 3 is reached. To ensure stope stability, ore support pillars 7 are reserved within the stope, with a size of no less than 4 meters × 4 meters and a spacing of 7-9 meters. Simultaneously, along the safety exit direction of the mining face, i.e., the sidewall of the cutting incline 4, temporary wire mesh enclosure 10 is installed to ensure safety. After all stope mining is completed, the entrance to the cutting incline 4 is sealed with concrete, completing the mining cycle for this block.

[0044] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for room-and-pillar phosphate mining with pre-filled continuous pillars, characterized in that: The method includes: S1. Advance mining preparation: At the same time or before the current mining block is being mined, advance construction of the mining preparation roadway for the next block to be mined; the mining preparation roadway includes the cutting uphill (4) arranged along the dip of the ore body and the strip roadway arranged along the strike of the ore body. S2, Strip-type filling to construct continuous inter-column: The strip-type roadway at a specific location completed in step S1 is continuously and densely filled with concrete. After the filling body hardens, a continuous concrete structure is formed. The continuous concrete structure constitutes the inter-column (6) of the ore block and is used to support the top and bottom plates, simultaneously replacing the functions of the top column (2) and bottom column (3) required by the ore block. S3. Mining of ore blocks: After the inter-block pillars (6) reach the design strength, the ore blocks formed by the inter-block pillars (6) are mined in accordance with the room-and-pillar mining process under the lateral and top and bottom plate support provided by the inter-block pillars (6). No ore top pillars, bottom pillars and continuous inter-block pillars are reserved during the mining process.

2. The method for pre-filled continuous pillar construction in room-and-pillar phosphate mining according to claim 1, characterized in that: in In step S1, the specific construction method for advance preparation is as follows: Simultaneously, the construction cuts the uphill (4) and the connecting roadway (5). The width of the cuts (4) and the connecting roadway (5) is 4-4.5 meters, and the completed roadway is supported by anchor bolts throughout. The connecting roadway (5) is located on one side of the mine and is used to connect adjacent mining units.

3. The method for room-and-pillar phosphate mining with pre-filled continuous pillars according to claim 2, characterized in that: Step S1 also includes construction steps along the designed top column (2) location: In the upper middle section, the mining was arranged, and the No. 1 bottom roadway and the No. 7 bottom roadway were constructed from the cutting uphill (4) to both sides respectively; The width of the No. 1 and No. 7 roadways is 4-4.5 meters, and they are connected to the middle / segment roadway (1) of the previous middle section to form a return air inlet (8) and an emergency exit; Anchor bolt support was installed in the No. 1 and No. 7 bottom roadways.

4. A method for pre-filled continuous pillar-type phosphate mining according to claim 3, characterized in that: in Before step S2, there is also a step of processing the connecting alley (5): The connecting lane (5) is filled with wet pouring to form an auxiliary support structure or isolation zone.

5. The method for room-and-pillar phosphate mining with pre-filled continuous pillars according to claim 3, characterized in that: the specific implementation object of "strip-type filling to construct continuous pillars" in step S2 is the No. 7 bottom roadway: The No. 7 Ladi roadway is a strip-type roadway used to construct the inter-block pillar (6); When the construction of the No. 1 bottom roadway is completed and the construction of the No. 2 bottom roadway is half completed, the No. 7 bottom roadway is poured to form the inter-block pillar (6).

6. A method for room-and-pillar phosphate mining with pre-filled continuous pillars as described in claim 5, characterized in that: In step S3, "mining of ore blocks" proceeds according to the following time sequence: After the construction of No. 1 bottom roadway is completed, the construction of No. 2 bottom roadway is 50% complete, and the pouring of No. 7 bottom roadway is completed, the construction of No. 3 bottom roadway will begin. At the same time, back mining was carried out in the No. 1 bottom roadway area.

7. A method for room-and-pillar phosphate mining with pre-filled continuous pillars as described in claim 6, characterized in that: During the mining process, as the bottom roadway is advanced, point pillars (7) are retained in the stope to support the inter-block pillars (6); Point column (7) is an ore point column with a size of not less than 4 meters × 4 meters, and the spacing between adjacent point columns (7) is set to 7-9 meters.

8. A method for room-and-pillar phosphate mining with pre-filled continuous pillars as described in claim 1, characterized in that: in Step S3, the ore block recovery process, also includes safety protection steps: Temporary wire mesh enclosure (10) is used to close the mining area along the direction of the safety exit at the mining face to prevent loose rocks from falling or personnel from accidentally entering unsafe areas.

9. A method for room-and-pillar phosphate mining with pre-filled continuous pillars as described in any one of claims 1 to 8, characterized in that: The mining operation in step S3 adopts mechanized operation, and the cutting uphill (4) serves as the free face and transportation and ventilation channel during the mining period; During the mining process, the return air passage (8) formed by the connection with the middle / segment roadway (1) is used to form a waste air return air flow path.

10. A method for room-and-pillar phosphate mining with pre-filled continuous pillars as described in claim 1, characterized in that: The method also includes the following steps: S4. Post-processing: Following steps S1 to S3, the mine is backed up to the bottom pillar (3) position. After the entire mine is backed up, the entrance to the cutting uphill (4) is sealed by pouring concrete to complete the mining cycle of the block.

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