阅读说明：本技术 一种离子吸附型稀土堆浸的可生长式堆体结构及堆浸方法 (Ion adsorption type rare earth heap leaching growing type heap structure and heap leaching method ) 是由 杨建华 王泽明 姚池 鞠炜 张小波 于 2021-01-04 设计创作，主要内容包括：本发明公开了一种离子吸附型稀土堆浸的可生长式堆体结构及堆浸方法,涉及湿法冶金技术领域,包括堆体本体,堆体本体的底部设置在底层基岩上,堆体本体的竖向一侧与堆场端部基岩之间设置有注液管网,注液管网用于向堆体本体进行侧向喷射浸取剂,堆体本体沿横向堆置方向分为若干级堆体,堆体的顶部用于进行植被修复。本发明设置可侧向喷射浸取剂的注液管网,提高了布液方式的可控性,并且在侧向进行注射,堆体本体的顶部不会受到浸取剂影响,为堆体本体顶部的植被修复保留了一定的空间；逐级进行稀土的可生长式堆浸(堆置浸取),可以保证每一级堆体的浸取效率,提高了稀土的利用率,保证稀土在堆浸过程中的稳定浸取,减少资源浪费。(The invention discloses a growing type heap structure for ion adsorption type rare earth heap leaching and a heap leaching method, and relates to the technical field of hydrometallurgy. The liquid injection pipe network capable of laterally spraying the leaching agent is arranged, so that the controllability of a liquid distribution mode is improved, the liquid injection is performed in a lateral direction, the top of the stack body is not affected by the leaching agent, and a certain space is reserved for vegetation restoration at the top of the stack body; the step-by-step growing heap leaching (heap leaching) of the rare earth can ensure the leaching efficiency of each level of the heap body, improve the utilization rate of the rare earth, ensure the stable leaching of the rare earth in the heap leaching process and reduce the resource waste.)

1. A kind of ion adsorption type rare earth heap soaks can grow the heap body structure, characterized by that: including the heap body, the bottom of heap body sets up on the bottom bed rock, be provided with between the vertical one side of heap body and the heap end portion bed rock and annotate the liquid pipe network, annotate the liquid pipe network be used for to the heap body carries out the side direction and sprays the leaching agent, the heap body is divided into a plurality of grades of heaps along horizontal heap orientation, the top of heap is used for carrying out the vegetation restoration.

2. The ion-adsorbing rare earth heap-leached growable stack structure of claim 1, wherein: each level of the stack body comprises an upper layer stack body, a permeable layer and a lower layer stack body from top to bottom, the compaction degree of the permeable layer is greater than that of the upper layer stack body and that of the lower layer stack body, and the permeability coefficient of the permeable layer is smaller than that of the upper layer stack body and that of the lower layer stack body.

3. The ion-adsorbing rare earth heap-leached growable stack structure of claim 1, wherein: the cross section of each level of the pile body perpendicular to the transverse stacking direction is trapezoidal, the length of the top of each level of the pile body is 3m, and the height of each level of the pile body is 10 m.

4. The ion-adsorbing rare earth heap-leached growable stack structure of claim 1, wherein: and impermeable layer bottom cushions are arranged between the bottom of each stage of the pile body and the bottom bedrock.

5. The ion-adsorbing rare earth heap-leached growable stack structure of claim 1, wherein: the front of the bottom of each pile body is provided with a main liquid collecting channel, and the bottom bedrocks on two sides of the bottom of the pile body are provided with auxiliary liquid collecting channels.

6. The ion-adsorbing rare earth heap-leached growable stack structure of claim 1, wherein: the stacking bodies of a plurality of stages are respectively a first-stage stacking body, a second-stage stacking body, a third-stage stacking body and an Nth-stage stacking body along the transverse stacking direction, N is more than or equal to 4, the slope angles of the first-stage stacking body, the second-stage stacking body and the third-stage stacking body along the transverse stacking direction are sequentially reduced, the slope angle of the first-stage stacking body along the transverse stacking direction is 55-60 degrees, the slope angle of the second-stage stacking body along the transverse stacking direction is 50-55 degrees, and the slope angles of the third-stage stacking body and the Nth-stage stacking body along the transverse stacking direction are 45-50 degrees.

7. The ion-adsorbing rare earth heap-leached growable stack structure of claim 1, wherein: the liquid injection pipe network comprises a transverse main pipe and a plurality of vertical branch pipes communicated with the transverse main pipe, a plurality of injection ports are formed in each vertical branch pipe, and the injection port at the uppermost end is lower than the top of the pile body.

8. A heap leach process for using the ion-adsorbing rare earth heap leached growable heap structure of any one of claims 1 to 7, characterised in that: the method comprises the following steps:

s1: vertically arranging a liquid injection pipe network on bedrock at the end part of the storage yard;

s2: transversely dividing the pile body into a plurality of levels of piles for piling, vertically dividing each level of piles into three layers of an upper layer pile, a permeable layer and a lower layer pile for piling, keeping the height of each level of piles unchanged, adjusting the slope angle of each level of piles to ensure the stability of the piles, arranging a main liquid collecting channel on one side of each level of piles in the outward piling direction, and arranging auxiliary liquid collecting channels on two sides of the pile body;

s3: heap leaching is carried out on each level of stack body, the injection pressure of leaching agent in a liquid injection pipe network is adjusted in the process of heap leaching of the stack body stage by stage so as to ensure normal leaching of the stack body of each level, and vegetation restoration is carried out on the top of the stack body of the previous level in the process of heap leaching of the stack body of the next level;

s4: and when the leaching efficiency of the last-stage stack body begins to be obviously reduced, the whole stack body is completely leached, and vegetation restoration is carried out on the top of the last-stage stack body.

9. The heap leach of a growable heap structure using ion-adsorbing rare earth heap leaching according to claim 8, wherein: in S3, the heap leaching process of each stage of the stack body includes the following steps:

a 1: opening a pressurizing pipe at the end part, spraying a leaching agent through a liquid injection pipe network, collecting rare earth mother liquor by a main liquid collecting ditch and an auxiliary liquid collecting ditch of a first-stage stack body in the leaching process, filling the main liquid collecting ditch of the first-stage stack body after the leaching and collecting of the first-stage stack body is finished, not performing treatment on the auxiliary liquid collecting ditch, and filling the main liquid collecting ditch of the first-stage stack body to be lower than the first-stage stack body;

a 2: the bottom pad of the impermeable layer of the second-stage stack body is connected with the bottom pad of the impermeable layer of the first-stage stack body, the step of the first-stage stack body is repeated, the second-stage stack body is subjected to heap leaching, and vegetation restoration is started to be carried out on the top of the first-stage stack body at the same time;

a 3: the heap leaching method of the third-stage heap is the same as that of the second-stage heap, heap leaching is carried out step by step, and vegetation restoration is carried out on the top of the previous-stage heap.

10. The heap leach of a growable heap structure using ion-adsorbing rare earth heap leaching according to claim 8, wherein: in S3, in the process of heap leaching of the heap, the lateral injection pressure of the leaching agents of the first-stage heap, the second-stage heap and the third-stage heap is kept unchanged, after the heap leaching of the third-stage heap is finished, the lateral injection pressure of the leaching agents is increased, and the specific injection pressure is determined according to the actual engineering condition.

Technical Field

The invention relates to the technical field of hydrometallurgy, in particular to a growing type heap structure for ion adsorption type rare earth heap leaching and a heap leaching method.

Background

The ion-adsorption type rare earth is a mineral which is adsorbed on the clay surface by hydration or hydroxyl hydration ions and is widely distributed in south China.

At present, the ion adsorption type rare earth is mainly extracted by an in-situ leaching method and a heap leaching method. In-situ leaching is to inject a leaching agent into an in-situ mine, and obtain a single rare earth material through purification, impurity removal, precipitation, calcination and extraction separation of mother liquor. In the in-situ leaching process, the seepage path of a leaching agent is often uncontrollable, and the leaching agent can diffuse and seep into the surrounding environment, so that the underground water and the surrounding environment of the in-situ mine are seriously polluted. In some in-situ rare earth mines with complex environmental conditions, the geological characteristics of the rare earth mines do not meet the basic requirements of leaching engineering, and part of the rare earth mines are not suitable for in-situ leaching and collection. Compared with in-situ ore leaching, heap leaching can reduce the pollution to the surrounding environment in the in-situ ore leaching, has better controllability, and has higher extraction rate to the rare earth with different grades than the in-situ ore leaching, but in the process of heap leaching, the rare earth ore is removed from the in-situ mine, and the in-situ vegetation is damaged. As shown in fig. 1, the conventional rare earth heap leaching method carries the rare earth ore from in-situ mining to the storage yard for leaching, sprays a leaching agent 15 at the top, repairs vegetation of the leached rare earth heap, and splits the mining, leaching and repairing, and the heap leaching method increases the engineering cost and has problems related to ecological environment. Aiming at the requirements of green mines, vegetation restoration is carried out simultaneously in the heap leaching process, which has important significance for green development of ion-adsorption type rare earth, and because the leaching agent 15 is injected into the heap body from the top in the traditional heap leaching method, the top of the heap body 14 is fully contacted with the leaching agent 15, and vegetation restoration of the top of the rare earth heap body 14 cannot be carried out simultaneously in the heap leaching process.

Disclosure of Invention

The invention aims to provide a growing type heap structure for ion adsorption type rare earth heap leaching and a heap leaching method, which are used for solving the problems in the prior art.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides an ion adsorption type rare earth heap leaching growable heap body structure, which comprises a heap body, wherein the bottom of the heap body is arranged on a bottom bed rock, a liquid injection pipe network is arranged between the vertical side of the heap body and the bed rock at the end part of a heap field, the liquid injection pipe network is used for laterally injecting leaching agents to the heap body, the heap body is divided into a plurality of levels of heaps along the transverse stacking direction, and the top of the heap body is used for vegetation restoration.

Preferably, each level of the stack body comprises an upper layer stack body, a permeable layer and a lower layer stack body from top to bottom, the compaction degree of the permeable layer is greater than that of the upper layer stack body and that of the lower layer stack body, and the permeability coefficient of the permeable layer is smaller than that of the upper layer stack body and that of the lower layer stack body.

Preferably, the cross section of each level of the stack body perpendicular to the transverse stacking direction is trapezoidal, the length of the top of each level of the stack body is 3m, and the height of each level of the stack body is 10 m.

Preferably, impermeable layer bottom mats are arranged between the bottoms of all the stages of the stacks and the bottom bedrock.

Preferably, the front of the bottom of the pile body at each stage is provided with a main liquid collecting channel, and the bottom bedrocks at two sides of the bottom of the pile body are provided with auxiliary liquid collecting channels.

Preferably, the plurality of stages of the stacks are respectively a first stage stack, a second stage stack, a third stage stack and an Nth stage stack along the transverse stacking direction, N is more than or equal to 4, the slope angles of the first stage stack, the second stage stack and the third stage stack along the transverse stacking direction are sequentially reduced, the slope angle of the first stage stack along the transverse stacking direction is 55-60 degrees, the slope angle of the second stage stack along the transverse stacking direction is 50-55 degrees, and the slope angles of the third stage stack and the Nth stage stack along the transverse stacking direction are 45-50 degrees.

Preferably, the liquid injection pipe network comprises a transverse main pipe and a plurality of vertical branch pipes communicated with the transverse main pipe, a plurality of injection ports are formed in each vertical branch pipe, and the injection port at the uppermost end is lower than the top of the pile body.

The invention also provides a heap leaching method of the ion adsorption type rare earth heap leaching growing type heap structure, which comprises the following steps:

s1: vertically arranging a liquid injection pipe network on bedrock at the end part of the storage yard;

s2: transversely dividing the pile body into a plurality of levels of piles for piling, vertically dividing each level of piles into three layers of an upper layer pile, a permeable layer and a lower layer pile for piling, keeping the height of each level of piles unchanged, adjusting the slope angle of each level of piles to ensure the stability of the piles, arranging a main liquid collecting channel on one side of each level of piles in the outward piling direction, and arranging auxiliary liquid collecting channels on two sides of the pile body;

s3: heap leaching is carried out on each level of stack body, the injection pressure of leaching agent in a liquid injection pipe network is adjusted in the process of heap leaching of the stack body stage by stage so as to ensure normal leaching of the stack body of each level, and vegetation restoration is carried out on the top of the stack body of the previous level in the process of heap leaching of the stack body of the next level;

s4: and when the leaching efficiency of the last-stage stack body begins to be obviously reduced, the whole stack body is completely leached, and vegetation restoration is carried out on the top of the last-stage stack body.

Preferably, in S3, the heap leaching process of each stage of the stack body includes the following steps:

a 1: opening a pressurizing pipe at the end part, spraying a leaching agent through a liquid injection pipe network, collecting rare earth mother liquor by a main liquid collecting ditch and an auxiliary liquid collecting ditch of a first-stage stack body in the leaching process, filling the main liquid collecting ditch of the first-stage stack body after the leaching and collecting of the first-stage stack body is finished, not performing treatment on the auxiliary liquid collecting ditch, and filling the main liquid collecting ditch of the first-stage stack body to be lower than the first-stage stack body;

a 2: the bottom pad of the impermeable layer of the second-stage stack body is connected with the bottom pad of the impermeable layer of the first-stage stack body, the step of the first-stage stack body is repeated, the second-stage stack body is subjected to heap leaching, and vegetation restoration is started to be carried out on the top of the first-stage stack body at the same time;

a 3: the heap leaching method of the third-stage heap is the same as that of the second-stage heap, heap leaching is carried out step by step, and vegetation restoration is carried out on the top of the previous-stage heap.

Preferably, in S3, during the heap leaching step by step, the lateral injection pressures of the leaching agents of the first-stage heap, the second-stage heap and the third-stage heap are kept unchanged, and after the heap leaching of the third-stage heap is finished, the lateral injection pressure of the leaching agents is increased, and the specific injection pressure is determined according to the actual engineering conditions.

Compared with the prior art, the invention has the following technical effects:

according to the invention, the liquid injection pipe network capable of laterally spraying the leaching agent is arranged between the bedrock at the end part of the storage yard and the stack body, so that the controllability of a liquid distribution mode is improved, and the injection is performed in the lateral direction, so that the top of the stack body is not influenced by the leaching agent, and a certain space is reserved for vegetation restoration at the top of the stack body; the stack body is divided into a plurality of stages, the rare earth can be grown and heap leached (heap leaching) step by step, the leaching efficiency of each stage of stack can be ensured, in the process of leaching the next stage of stack, the leaching agent simultaneously flows through the previous stage of stack, the utilization rate of the rare earth is improved, the rare earth is ensured to be stably leached in the process of heap leaching, and the resource waste is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of a conventional ion-adsorption-type rare earth heap leaching process;

FIG. 2 is a schematic view of the structure of the ion-adsorbing rare earth heap-leached growable heap of the present invention (in the transverse stacking direction);

FIG. 3 is a schematic view of the structure of the ion-adsorbing rare earth heap-leached growable heap of the present invention (perpendicular to the transverse stacking direction);

FIG. 4 is a schematic view of a liquid injection pipe network according to the present invention;

wherein: 1-yard end bedrock, 2-liquid injection pipe network, 3-impermeable layer bottom pad, 4-bottom bedrock, 5-main liquid collecting channel, 6-auxiliary liquid collecting channel, 7-main liquid collecting channel to be filled and repaired, 8-permeable layer, 9-upper layer stack body, 10-lower layer stack body, 11-first layer stack body, 12-second layer stack body, 13-third layer stack body, 14-stack body, 15-leaching agent, 21-transverse main pipe, 22-vertical branch pipe and 23-jet orifice.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

The invention aims to provide a growing type heap structure for ion adsorption type rare earth heap leaching and a heap leaching method, which are used for solving the problems in the prior art.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Example one

As shown in fig. 2-4: the embodiment provides a growing formula heap structure that ion adsorption type rare earth heap leached, including the heap body, the bottom of heap body sets up on bottom bed rock 4, is provided with between the vertical one side of heap body and the yard tip bed rock 1 and annotates liquid pipe network 2, annotates liquid pipe network 2 and is used for carrying out the side direction to the heap body and sprays the leaching agent, the ammonium sulfate solution is selected to the leaching agent, the heap body is divided into a plurality of grades of heaps along horizontal heap (the direction is transversely piled for from the right to the left in figure 2), the top of heap is used for carrying out the vegetation restoration.

Specifically, in the present embodiment, each level of the stack includes an upper stack 9, a permeable layer 8 and a lower stack 10 from top to bottom, the degree of compaction of the permeable layer 8 is greater than that of the upper stack 9 and the lower stack 10, the permeability coefficient of the permeable layer 8 is less than that of the upper stack 9 and the lower stack 10, and the ratio of compacted porosity of the permeable layer 8 is about 0.6. The rare earth stacks at all levels are stacked in layers, and the permeability of the permeable layer 8 in the middle is weak, so that more leaching agents can flow to the upper stack 9, and the utilization rate of rare earth resources of the upper stack 9 is improved.

In this embodiment, the cross section of each level of the stack perpendicular to the transverse stacking direction is trapezoidal, the slopes on both sides of the trapezoid are 45 ° to 50 °, the width of the platform at the top of the trapezoid is 8m to 12m (based on the direction shown in fig. 3), the length of the top of each level of the stack is 3m (along the transverse stacking direction shown in fig. 2), and the height of each level of the stack is 10 m.

In this embodiment, an impermeable layer bottom mat 3 is arranged between the bottom of each level of the pile body and the bottom bedrock 4.

In this embodiment, the place ahead of the bottom of the heap of each level all is provided with main album of liquid ditch 5, is provided with on the bottom bed rock 4 of heap body bottom both sides and assists album of liquid ditch 6. The width of the main liquid collecting channel 5 is 1.2m, and the height is 0.6 m; the width of the auxiliary liquid collecting channel 6 is 0.8m, and the height is 0.4 m.

In the embodiment, the plurality of stages of stacks are respectively a first stage stack 11, a second stage stack 12, a third stage stack 13 and an Nth stage stack along the transverse stacking direction, N is more than or equal to 4, the slope angles of the first stage stack 11, the second stage stack 12 and the third stage stack 13 along the transverse stacking direction are sequentially reduced, the slope angle of the first stage stack 11 along the transverse stacking direction is 55-60 degrees, the slope angle of the second stage stack 12 along the transverse stacking direction is 50-55 degrees, the slope angles of the third stage stack 13 and the Nth stage stack along the transverse stacking direction are 45-50 degrees, and in the stacking process of each stage of stacks, the slope angles of the stages of stacks are adjusted, so that the stability of the stacks in the heap leaching process is ensured.

In this embodiment, the liquid injection pipe network 2 includes a horizontal main pipe 21 and a plurality of vertical branch pipes 22 communicated with the horizontal main pipe 21, each vertical branch pipe 22 is provided with a plurality of injection ports 23, and the injection port 23 at the uppermost end is lower than the top of the pile body. Annotate liquid pipe network 2 and select for use the PE water supply pipe, horizontal person in charge 21 selects for use the PE pipe of 50mm pipe diameter, vertical lateral pipe 22 selects for use the PE pipe of 20mm pipe diameter, each vertical lateral pipe 22 parallel arrangement, horizontal person in charge 21 and vertical lateral pipe 22's pipe diameter can be adjusted according to the actual engineering condition, the interval of each vertical lateral pipe 22 and the interval of each jet 23, should design according to the working shaft in the actual engineering and spray intensity, do at leachant jet 23 and prevent blockking up the processing, satisfy the leaching requirement of tombarthite, annotate the distance at liquid pipe network 2 tops apart from tombarthite heap body top and should design according to the required height of vegetation restoration, in order to satisfy later stage vegetation restoration's needs.

In the embodiment, the liquid injection pipe network 2 capable of laterally spraying the leaching agent is arranged between the bed rock 1 at the end part of the storage yard and the stack body, so that the controllability of a liquid distribution mode is improved, the injection is performed in the lateral direction, the top of the stack body is not influenced by the leaching agent, a certain space is reserved for vegetation restoration at the top of the stack body, the leaching agent is sprayed in the lateral direction to leach and collect rare earth, and the utilization rate of the rare earth of each stage of the stack body is improved; the heap body is divided into a plurality of stages, the rare earth can be grown and heap leached (heap leaching) step by step, after the rare earth leaching of the previous stage of heap is finished, the heap leaching of the next stage of heap is carried out, the leaching efficiency of each stage of heap can be ensured, and in the process of leaching the next stage of heap, a leaching agent simultaneously flows through the previous stage of heap, so that the utilization rate of the rare earth is improved, the stable leaching of the rare earth in the heap leaching process is ensured, and the resource waste is reduced; the slope angle of the stacks of different levels and the pressurizing strength of the lateral spraying leaching agent are adjusted, and the stability of the rare earth stacks in the rare earth heap leaching process is improved.

Example two

The embodiment provides a heap leaching method adopting the first embodiment, which includes the following steps:

s1: a liquid injection pipe network 2 is vertically arranged on the bedrock 1 at the end part of the storage yard, and an impermeable layer bottom pad 3 of a first-stage stack body 11 is arranged while the liquid injection pipe network 2 is arranged, wherein the angle of the impermeable layer bottom pad is 3-5 degrees with the transverse stacking direction;

s2: transversely dividing the pile body into a plurality of piles for piling, controlling the section of each pile perpendicular to the transverse piling direction to be approximately symmetrical trapezoid, vertically dividing each pile into an upper pile 9, a permeable layer 8 and a lower pile 10 for piling, selecting rare earth with lower compactness and larger permeability coefficient for the upper pile 9 and the lower pile 10, selecting a rare earth thin layer with high compactness and smaller permeability coefficient for the middle permeable layer 8, keeping the height of each pile unchanged, adjusting the slope angle of each pile to ensure the stability of the pile, after the piling is finished, arranging liquid collecting grooves around each stable pile, arranging a main liquid collecting groove 5 on one side of each pile in the outward piling direction, and arranging auxiliary liquid collecting grooves 6 on two sides of the pile body;

s3: after the liquid collecting ditches are arranged, heap leaching is carried out on each stage of the pile body, a pressurizing pipe at the end part is opened, a leaching agent is sprayed through a liquid injection pipe network 2, the upper part of each layer of the upper layer of the pile body 9 and the lower layer of the pile body 10 uses larger spraying pressure, the lower part of each layer of the upper layer of the pile body 9 and the lower layer of the pile body 10 can use relatively smaller spraying pressure, the spraying pressure of the leaching agent in the liquid injection pipe network 2 is adjusted in the pile body step-by-step heap leaching process to ensure the normal leaching of each stage of the pile body, rare earth mother liquid is collected by a main liquid collecting ditch 5 and an auxiliary liquid collecting ditch 6 in the leaching process, and vegetation restoration is carried out on the top of the front stage of the pile body in the later stage of pile body leaching process;

in S3, the heap leaching process of each stage of the stack includes the steps of: a 1: opening a pressurizing pipe at the end part, spraying a leaching agent through a liquid injection pipe network 2, collecting rare earth mother liquor by a main liquid collecting ditch 5 and an auxiliary liquid collecting ditch 6 of a first-stage stack body 11 in the leaching process, filling the main liquid collecting ditch 5 of the first-stage stack body 11 (a repaired main liquid collecting ditch 7 is filled as shown in figure 2) after the first-stage stack body 11 is leached and collected, not disposing the auxiliary liquid collecting ditch 6, and filling the main liquid collecting ditch 5 of the first-stage stack body 11 to be lower than the first-stage stack body 11; a 2: the impermeable layer bottom pad 3 of the second-stage stack body 12 is connected with the impermeable layer bottom pad 3 of the first-stage stack body 11, the step of the first-stage stack body 11 is repeated, the second-stage stack body 12 is subjected to heap leaching, and vegetation restoration is started to be carried out on the top of the first-stage stack body 11; a 3: the heap leaching method of the third-stage stack 13 is the same as that of the second-stage stack 12, heap leaching is carried out step by step, and vegetation restoration is carried out on the top of the previous-stage stack at the same time;

in S3, in the process of heap leaching the heap step by step, the lateral spray pressure of leaching agents of the first-stage heap 11, the second-stage heap 12 and the third-stage heap 13 is kept unchanged, after the heap leaching of the third-stage heap 13 is finished, the lateral spray pressure of the leaching agents is increased, and the specific spray pressure is determined according to the actual engineering condition;

s4: and when the leaching efficiency of the last-stage stack body begins to be obviously reduced, the whole stack body is completely leached, and vegetation restoration is carried out on the top of the last-stage stack body.

The principle and the implementation mode of the present invention are explained by applying specific examples in the present specification, and the above descriptions of the examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.