CN116837925A - A closed reclamation method for large pit tailings reservoirs - Google Patents

Abstract

The invention discloses a closed reclamation method for a large pit-type tailings reservoir. The adopted slurry discharge and backfill device (6) is composed of a slurry discharge pipe and a number of floating and sinking tubes. The several floating and sinking tubes are tied to both sides of the slurry discharge pipe. The end of the tailings tank is stably suspended on the water surface in the pit tailings reservoir, and there is a slurry discharge hole below the slurry discharge pipe. Add the set amount of backfill soil, water, and plant seeds into the slurry mixing tank (1) for mixing, and then transport the mixed slurry to the slurry discharge through the slurry air pump (10) and the mud transportation pipe (3) The slurry discharge pipe (8) of the backfill device (6) is discharged through the slurry discharge hole (11), so that a certain section of the upper tailings pit entrance of the pit-type tailings reservoir that needs to be backfilled is covered with soil. The invention is applied to the closed reclamation of large-scale pit-type tailings reservoirs. It ensures that the closure process and final reclamation of large-scale pit-type tailings reservoirs meet safety and environmental protection requirements while achieving low cost, simple construction and short lifespan. Cover with soil.

Description

A closed reclamation method for large pit tailings reservoirs

Technical field

The invention belongs to the technical field of pit-type tailings reservoir closed reservoir reclamation engineering, and in particular relates to a closed reservoir reclamation method using a large open-pit mining pit with a storage capacity of more than 10 million ^m3 as a tailings reservoir.

Background technique

The tailings pond is one of the three major control projects of the mine. It is an important production facility of the mining enterprise. It is mainly used to store tailings or other industrial waste residues discharged from metal and non-metal mines after ore separation. It is a place to maintain the mine. One of the necessary facilities for normal production. Tailings ponds that have reached the final designed elevation or are no longer undergoing tailing discharge operations should be closed. The content of the closure includes the regulation of the beach surface of the tailings pond. The beach surface improvement is to prevent the tailings pond beach surface from weathering after closure, causing dust and environmental pollution. The main project is to cover the tailings pond beach surface with soil and plant vegetation.

There are four main types of tailings ponds: valley-type tailings ponds, mountain-side tailings ponds, flat-land tailings ponds and river-cut tailings ponds. Normally, when these tailings reservoirs implement closed reservoir beach surface management, the accumulated water in the reservoir will first be drained. After the beach surface has sufficient bearing capacity, construction vehicles will be used to transport the surrounding soil to the reservoir for beach surface covering and greening. . In recent years, in order to achieve comprehensive management of open-pit mines after closure, considering that open-pit mines have the advantage of large storage capacity, do not require manual dam construction, have low cost, simple construction, and short life, open-pit mines are used as tail mines. Mine discharge sites can solve problems such as lack of land resources and low actual utilization rate.

As a tailings discharge site, open-pit mines have structural characteristics of a huge concave space that determines that pit-type tailings ponds are different from general tailings ponds. This is mainly reflected in the fact that there is no dry beach in the pit-type tailings ponds, and the tailings water can completely cover all tailings. Therefore, after the pit-type tailings reservoir stops discharging tailings, if the conventional tailings reservoir closed reclamation method is adopted (that is, the overlying water is completely pumped out, and the surrounding soil is transported by vehicle after the beach surface is consolidated and has bearing capacity) Covering soil and greening) for closed reclamation of pit tailings reservoirs will face the following problems: (1) Long closure period: vehicle transportation of covering soil requires a certain bearing capacity of the beach surface, and the beach surface of pit tailings ponds is flooded all year round. If it is necessary to achieve the beach surface bearing capacity to meet vehicle driving requirements, drainage consolidation is required. After all the water in the reservoir is pumped out, the beach surface in the reservoir is exposed to the natural wind. This process takes a long time. (2) Uneven soil covering: Transportation of covering soil in a vehicle garage can easily cause a soil squeezing effect, resulting in uneven and uneven covering of soil on the beach surface. (3) Serious environmental pollution: The traditional tailings reservoir closure method uses vehicles to transport surrounding soil. Due to the large amount of work, transport vehicles will inevitably produce a large amount of exhaust gas to complete the closure work, causing serious adverse effects on the atmosphere. (4) The safety of the disposal method is low: the tailings drainage and consolidation period in the open-pit mine is long, and the consolidation effect cannot be guaranteed. When the consolidation effect in some areas is weak, the use of vehicles to transport covering soil may easily cause vehicle damage, equipment overturning, etc. question. (5) Difficulties in construction organization and management: The use of vehicles to cover soil-covered closed reservoirs for reclamation requires a large number of personnel and engineering vehicles, making on-site construction organization and management difficult. Based on this, the present invention proposes a closed reclamation method for a large pit-type tailings reservoir.

Contents of the invention

The purpose of this invention is to provide a method that meets safety and environmental protection requirements, has low cost and is easy to construct in order to solve the shortcomings of the existing technology such as long storage period, uneven soil covering, easy environmental pollution, safety problems, and difficulty in construction organization. A simple and short-term closed reclamation method for large-scale pit tailings reservoirs.

In order to achieve the above objects of the present invention, a large-scale pit-type tailings reservoir closed reclamation method of the present invention adopts the following technical solutions to implement:

1) According to the size and shape of the upper tailings pit mouth of the pit-type tailings reservoir that needs to be backfilled, it is divided into several zones: first zone, second zone, third zone...;

2) Based on the geographical environment, transportation, line erection and distance from the tailings pit around the pit-type tailings reservoir, select a suitable location to build a slurry mixing tank, a slurry stacking tank, a slurry mixing tank, and a slurry stacking tank. The slurry stacking tank is equipped with a slurry air pump for transporting slurry; the outlet of the slurry air pump is connected to a mud transportation pipeline that is laid in a certain section of the upper tailings pit entrance above the pit-type tailings reservoir;

3) Arrange a slurry discharge and backfill device horizontally on the water surface of a certain section of the upper tailings pit entrance of the pit-type tailings reservoir that needs to be backfilled;

The described slurry discharge and backfill device is composed of a slurry discharge pipe and a number of floating and sinking cylinders. The several floating and sinking cylinders are tied to both ends of the slurry discharging pipe and are smoothly suspended on the water surface in the pit tailings reservoir; the slurry discharging pipe is One end is connected to the outlet of the mud conveying pipe, the other end of the slurry discharge pipe is a blind pipe, and a slurry discharge hole is provided below the slurry discharge pipe;

4) On the side of the upper tailings pit entrance of the pit-type tailings reservoir, there is a winch/blower equipment or remote controller that controls the movement of the slurry discharge and backfill device; the winch/blower equipment is equipped with a steel wire chain, and each steel wire The chain cable is removably assembled and connected to the corresponding floating and sinking tube arranged at one end of the slurry discharge pipe;

When a remote controller is used, an intelligent driving mechanism is set on the slurry discharge and backfill device, and the remote controller controls the slurry discharge and backfill device to move on the water surface in the pit tailings reservoir.

5) Add a set amount of backfill soil, water, and plant seeds into the slurry mixing tank and stir to prepare a mixed slurry, which is then transported by the slurry through the slurry air pump equipped in the slurry stacking tank. The pipeline transports the mixed slurry to the slurry discharge pipe of the slurry discharge and backfill device, and discharges it through the slurry discharge hole. The winch/blower equipment controls the slurry discharge and backfill device to repeatedly move at a constant speed on the water surface of a certain zone, thereby filling the pits that need to be backfilled. A certain section of the upper tailings pit entrance above the tailings pond will be covered with soil in situ;

6) When the covering soil thickness of a certain partition meets the reclamation requirements, move the slurry discharge and backfill device to the next partition to cover the soil until all partitions are completed.

Preferably, the mud transport pipeline and the slurry discharge pipeline are fixedly connected through a plug-in two-way joint.

Preferably, the number of floats and sinks located at both ends of the slurry discharge pipe is the same and the positions are opposite, so that the slurry discharge pipe is smoothly suspended on the water surface of the pit tailings reservoir.

Preferably, the diameter of the slurry discharge holes is 0.8cm-1.2cm, and the slurry discharge holes are arranged at equidistant intervals below the slurry discharge pipe.

Preferably, the mass concentration of the mixing slurry is 60-70%.

Preferably, the thickness of the covering soil is 20cm-50cm.

Preferably, the width of each partition is 6m-15m.

Preferably, the floating tube is made of high-density polyethylene or polyester synthetic material.

When the length of the slurry discharge pipe is too long, the slurry discharge pipe is composed of several shorter pipes connected into one whole body through an L-shaped two-way threaded joint.

Further, the thickness of the covering soil is 20cm-30cm; the mass concentration of the mixing slurry is 65-70%, in which the mass proportion of plant seeds in the mixing slurry is 1-5%; each The width of the partition is 6m-10m.

The closed reclamation method of a large pit-type tailings reservoir of the present invention has the following positive effects after adopting the above technical solution:

(1) The slurry discharge and backfill device developed by the present invention uses the buoyancy of water to make the slurry discharge pipe float on the water surface of the pit tailings reservoir, and uses a winch/blower equipment to assist the retraction and release of the steel wire chain to achieve control of the slurry discharge and backfill device on the water surface. It moves at a constant speed repeatedly, and the mixed cementing slurry is transported to the slurry discharge pipe through the slurry conveying pipe, and is discharged through a number of slurry discharge holes provided in the slurry discharge pipe for soil covering, which effectively avoids the vehicle soil covering process in the existing technology. The resulting soil squeezing effect results in even soil covering, smooth beach surface, and better soil covering effect.

(2) The present invention uses the in-situ soil covering method to cover the tailings pit beach surface with soil directly on the water surface, which saves the early tailings drainage and consolidation time, greatly shortens the period of closed reservoir reclamation operation, and reduces a lot of manpower and time. The investment in vehicles has the advantages of low cost and simple project organization and management.

(3) The present invention drives the slurry discharge and backfilling device through the winch/blowing equipment and steel wire chain cables to cover the soil. The whole process of closed reservoir reclamation is greener, lower-carbon, and more environmentally friendly.

(4) The present invention eliminates the need for transportation vehicles to cover the pit with soil, and effectively avoids accidents such as vehicle damage and equipment overturning in the pit.

(5) The entire process of the present invention is carried out in a wet environment, effectively avoiding the generation of dust and protecting the environment; the present invention is applied to closed reclamation of large-scale pit-type tailings reservoirs, ensuring the closure process of large-scale pit-type tailings reservoirs and After the final reclamation, it not only meets safety and environmental protection requirements, but also achieves low-cost, simple construction and short-term covering soil.

Description of the drawings

Figure 1 is a schematic diagram of the system layout and structure of the design of a large-scale pit-type tailings reservoir closed reclamation method according to the present invention;

Figure 2 is a schematic structural diagram of the slurry discharge and backfill device used in the method of the present invention;

Figure 3 is a cross-sectional view of A-A in Figure 2;

Figure 4 is a schematic structural diagram of a plug-in two-way connector used in the method of the present invention.

The reference numbers are: 1-slurry mixing tank; 2-slurry stacking tank; 3-slurry transportation pipeline; 4-wire chain; 5-winch/blast equipment; 6-slurry discharge and backfill device; 7-floating and sinking cylinder; 8-slurry discharge pipe; 9-plug-in one-way two-way joint; 10-slurry air pump; 11-slurry discharge hole; 12-L-type two-way threaded joint.

Detailed ways

In order to further describe the present invention, a closed reclamation method for a large pit-type tailings reservoir of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

From the schematic system layout structure diagram of the design of a large-scale pit-type tailings closed storage reclamation method of the present invention shown in Figure 1 and combined with Figures 2 and 3, it can be seen that a large-scale pit-type tailings closed storage tank of the present invention Reclamation methods are implemented using the following technical solutions:

1) According to the size and shape of the upper tailings pit mouth of the pit-type tailings reservoir that needs to be backfilled, it is divided into several zones: first zone, second zone, third zone..., the width of each zone is 6m-10m.

2) Based on the geographical environment, transportation, line erection and distance from the tailings pit around the pit tailings reservoir, select the appropriate location to build the slurry mixing tank 1 and slurry stacking tank 2, slurry mixing tank 1 and slurry stacking tank Tank 2 is connected with a pipeline, and the slurry stacking tank 2 is equipped with a slurry air pump 10 for transporting slurry; the outlet of the slurry air pump 10 is connected to the mud transportation pipeline 3 that is laid in a certain section of the upper tailings pit entrance of the pit-type tailings reservoir. .

3) Arrange the slurry discharge and backfill device 6 horizontally on the water surface of a certain section of the upper tailings pit entrance of the pit-type tailings reservoir that needs to be backfilled.

The described slurry discharge and backfill device 6 is composed of a slurry discharge pipe 8 and several floating and sinking tubes 7. The floating and sinking tubes 7 are made of environmentally friendly materials such as HMWHDPE (high molecular polyethylene), which is beneficial to increasing the service life of the settling tubes 7. and reduce environmental pollution. A number of floating and sinking drums 7 are tied to both ends of the slurry discharge pipe 8. Several settling drums 7 are fixedly connected to the slurry discharge pipe 8 through steel frames. The number of floating and sinking drums 7 located at both ends of the slurry discharge pipe 8 is the same and their positions are opposite, so that the slurry discharge pipes 8. Use the buoyancy of water to float smoothly on the water surface of the pit tailings reservoir. One end of the slurry discharge pipe 8 is fixedly connected to the outlet of the mud conveying pipe 3 through a plug-in one-way two-way joint 9. The other end of the slurry discharge pipe 8 is a blind pipe. The bottom of the slurry discharge pipe 8 is arranged at intervals and arranged in sequence. The slurry hole 11 enables the mixing slurry to be discharged evenly and improves the uniformity of the covering soil; the diameter of the slurry discharge hole 11 is 0.8cm-1.2cm.

4) On the side of the upper tailings pit mouth of the pit-type tailings reservoir, there is correspondingly provided a winch/blower equipment 5 or a remote controller that controls the movement of the slurry discharge and backfill device 6; the winch/blower equipment 5 is equipped with a steel wire chain 4 , each steel wire chain cable 4 is assembled and connected with the corresponding floating drum 7 arranged at one end of the slurry discharge pipe 8; with this arrangement, the four winches/blower equipment 5 located on both sides assist in the retraction and unfolding of the steel wire chain cable 4 to achieve controlled discharge. The slurry backfill device moves repeatedly and uniformly on the water surface. The steel wire chain rope 4 is made of metal, is light in weight, is easy to cooperate with the winch/blower equipment 5, and has high strength, which can effectively drive the movement of the slurry discharge and backfill device and improve the soil covering efficiency.

5) Add a set amount of backfill soil, water, and plant seeds into the slurry mixing tank 1 and stir to prepare a mixed slurry, which is then transported through the slurry air pump 10 equipped in the slurry stacking tank 2 , the mixed slurry is transported to the slurry discharge pipe 8 of the slurry discharge and backfill device 6 through the mud transport pipe 3, and is discharged through the slurry discharge hole 11, thereby filling a certain section of the upper tailings pit entrance of the pit-type tailings reservoir that needs to be backfilled. Cover with soil. The thickness of the covering soil is 20cm-30cm, and the mass concentration of the mixing slurry is controlled at 66-69%.

6) When the thickness of the covering soil in a certain partition meets the reclamation requirements, move the slurry discharge and backfill device (6) to the next partition to cover the soil until all partitions are completed.

From the schematic structural diagram of the plug-in two-way joint used in the method of the present invention shown in Figure 4 and combined with Figure 1, it can be seen that when the length of the slurry discharge pipe 8 is too large, the slurry discharge pipe 8 is composed of several The shorter pipes are connected into a whole body through the L-shaped two-way threaded joint 12.

The whole closed reservoir reclamation process of the method of the present invention is greener, lower-carbon, more environmentally friendly, and effectively avoids the soil squeezing effect caused by the vehicle soil covering process in the prior art. The soil covering is even, the beach surface is flat, and the soil covering effect is better; The in-situ soil covering method is used to cover the tailings pit beach surface with soil directly on the water surface, which saves the early tailings drainage and consolidation time, greatly shortens the period of closed reservoir reclamation operations, and reduces a large amount of manpower and vehicle capital investment. It has the advantages of low cost and simple project organization and management; it eliminates the need for transportation vehicles to cover the pit with soil, effectively avoiding accidents such as vehicle damage and equipment overturning in the pit; the entire process of the present invention is carried out in a wet environment, effectively avoiding dust production and environmental protection; the present invention is applied to the closed reclamation of large-scale pit-type tailings reservoirs to ensure that the closure process and final reclamation of large-scale pit-type tailings reservoirs meet safety and environmental protection requirements while achieving low cost and low construction costs. Simple and short-term soil covering.

Claims (10)

1. A large pit type tailing pond closed-reservoir reclamation method is characterized by being implemented by adopting the following technical scheme:

1) Dividing the size and shape of the pit mouth of the upper tailings in the pit type tailings pond to be backfilled into a plurality of subareas according to the requirement: one, two, three partition.

2) According to the geographical environment around the pit type tailing pond, traffic transportation, line erection and distance from the tailing pit, a slurry mixing tank (1) and a slurry stacking groove (2) are built at proper positions, the slurry mixing tank (1) and the slurry stacking groove (2) are connected through a pipeline, and a slurry air pump (10) for conveying slurry is arranged in the slurry stacking groove (2); the outlet of the slurry air pump (10) is connected with a slurry conveying pipeline (3) paved to a certain area of the tailing pot mouth at the upper part of the pit type tailing pond;

3) Transversely arranging a slurry discharging backfilling device (6) on the water surface of a certain partition of the pit mouth of the upper tailings of the pit-type tailings pond to be backfilled;

the slurry discharging backfill device (6) is formed by combining a slurry discharging pipeline (8) and a plurality of floating and sinking cylinders (7), wherein the floating and sinking cylinders (7) are bound at two ends of the slurry discharging pipeline (8) and stably suspend on the water surface in the pit type tailing pond; one end of a slurry discharge pipeline (8) is connected with an outlet of the slurry conveying pipeline (3), the other end of the slurry discharge pipeline (8) is a blind pipe, and a slurry discharge hole (11) is arranged below the slurry discharge pipeline (8);

4) A winch/blower device (5) or a remote controller for controlling the slurry discharging and backfilling device (6) to move is correspondingly arranged at the side edge of the upper tailing pot mouth of the pit type tailing pond; the winch/blower equipment (5) is provided with steel wire chain ropes (4), and each steel wire chain rope (4) is assembled and connected with a floating and sinking cylinder (7) correspondingly arranged at one end of the slurry discharging pipeline (8);

5) Adding a set amount of backfill soil, water and plant seeds into a slurry mixing pool (1) for stirring to prepare mixed slurry, conveying the mixed slurry to a slurry discharge pipeline (8) of a slurry discharge backfilling device (6) through a slurry conveying pipeline (3) by a slurry air pump (10) for conveying the slurry, and discharging the mixed slurry through a slurry discharge hole (11), thereby covering a certain partition of a tailing pot hole at the upper part of a pit type tailing pond needing backfilling;

6) When the soil covering thickness of a certain partition meets the reclamation requirement, the slurry discharging backfilling device (6) is moved to the next partition for soil covering until the soil covering of all the partitions is completed.

2. The large pit type tailing pond closed reclamation method as recited in claim 1, wherein the method comprises the following steps: the slurry conveying pipeline (3) is fixedly connected with the slurry discharging pipeline (8) through a plug-in type straight two-way joint (9).

3. The large pit type tailing pond closed reclamation method as recited in claim 1, wherein the method comprises the following steps: the floating and sinking cylinders (7) at the two ends of the slurry discharge pipeline (8) are the same in number and opposite in position, so that the slurry discharge pipeline (8) is stably suspended on the water surface of the pit type tailing pond.

4. The large pit type tailing pond closed reclamation method as recited in claim 1, wherein the method comprises the following steps: the aperture of the pulp discharging holes (11) is 0.8cm-1.2cm, and the pulp discharging holes (11) are sequentially arranged below the pulp discharging pipeline (8) at equal intervals.

5. The large pit type tailing pond closed reclamation method as recited in claim 1, wherein the method comprises the following steps: the mass concentration of the mixing slurry is 60-70%.

6. The large pit type tailing pond closed reclamation method as recited in claim 1, wherein the method comprises the following steps: the thickness of the covering soil is 20cm-50cm.

7. The large pit type tailing pond closing reclamation method according to claim 1, 2, 3, 4, 5 or 6, wherein the method comprises the following steps: the width of each partition is 6m-15m.

8. The large pit type tailing pond closing reclamation method as recited in claim 7, wherein: the floating and sinking cylinder (7) is made of high-density polyethylene or polyester synthetic material.

9. The large pit type tailing pond closing reclamation method as recited in claim 8, wherein the steps of: the slurry discharging pipeline (8) is formed by connecting a plurality of pipelines with shorter lengths into a whole through an L-shaped two-way threaded joint (12).

10. The large pit type tailing pond closing reclamation method as recited in claim 8, wherein the steps of: the thickness of the covering soil is 20cm-30cm; the mass concentration of the mixing slurry is 65-70%, wherein the mass ratio of the plant seeds in the mixing slurry is 1-5%; each partition has a width of 6m-10m.