Method for determining reasonable boundary line from open-pit mining to underground mining of mine

Abstract

The invention discloses a method for determining a reasonable boundary line from open-pit mining to underground mining of a mine. According to the technical scheme, the method comprises the steps that A, the stripping ratio is calculated; b, drawing a realm diagram; c, optimizing and adjusting; when the stripping ratio is calculated, the following factors including the ore volume, the stripping object volume and the economic and reasonable stripping ratio need to be considered. The method solves the problems of safety, environment, economy, technology and other defects in the existing method for determining the reasonable boundary line from open-pit mining to underground mining.

Description

Technical Field

[0001] The invention relates to the field of mine development technology, in particular to a method for determining a reasonable boundary for converting open-pit mining to underground mining. Background Art

[0002] Open-pit to underground mining refers to the method of first using open-pit mining on the upper part and then using underground mining on the lower part when the overburden of the ore deposit becomes thinner and extends to a larger extent. In the process of open-pit to underground mining, there is a gradual decrease in open-pit production and a gradual increase in underground production until the open-pit mine is closed and the underground mine reaches the designed scale. This period of time is called the transition period. The mining plan and technology in the transition period require that the mine continue to produce, mine safely, have a short transition period and save investment. In the process of open-pit to underground mining, it is necessary to consider the transition period recovery plan, the development system and mining technology of the open-pit to underground mining.

[0003] The existing methods for determining the reasonable boundary of open-pit to underground mining have some defects, which are mainly reflected in the following aspects: Safety issues: The stability of high slopes and boundary pillars is an important issue during the transition from open-pit mining to underground mining. The high slopes and boundary pillars left over from open-pit mining may have stability issues during underground mining, which may lead to safety accidents; Inadequate drainage measures: In open-pit and underground mining, drainage measures were not taken as designed, which may cause the groundwater level to rise and affect the safety of underground operations; Mining sequence problem: When open pit and underground mining are combined, the mining sequence does not conform to the design, which may lead to resource waste or reduced mining efficiency; Insufficient protective measures: Failure to adopt protective measures such as leaving safety top pillars or rock cushions as designed, which may lead to accidents such as roof collapse during underground mining; Environmental impact: Open-pit mining will destroy a large area of ​​local vegetation and have a great impact on the environment. Although underground mining can reduce surface damage, its drainage facilities and engineering workload are large, and it is easy to cause waterlogging problems in rainy climate conditions; Economic considerations: The existing methods mainly rely on the principle of economically reasonable stripping ratio when determining the boundary of open pit to underground mining. However, this method may ignore the influence of geological conditions, technical feasibility and environmental factors, resulting in certain limitations in actual operation. Technical feasibility: When determining the scope of open-pit mining, it is necessary to consider geological conditions such as the shape, thickness, and inclination of the ore body, as well as technical factors such as mining technology, equipment selection, and slope stability. If these factors are not fully considered, it may lead to technical infeasibility; Existing methods have defects in safety, environment, economy and technology when determining the reasonable boundary of converting open-pit mining to underground mining, and need to be further improved and optimized. Summary of the invention

[0004] The purpose of the present invention is to provide a method for determining a reasonable boundary of a mine from open pit to underground mining, so as to solve the problems of safety, environment, economy and technology defects in the existing determination of a reasonable boundary of a mine from open pit to underground mining.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A method for determining a reasonable boundary for converting open pit mining to underground mining is implemented by the following technical solutions: A. Calculate the stripping ratio; B. Draw the boundary map; C. Optimize and adjust; When calculating the stripping ratio, the following factors need to be considered: ore volume, stripping material volume and economically reasonable stripping ratio.

[0006] Through the above steps, detailed operations can be carried out to determine the boundary of open-pit mining to underground mining, ensuring the economy, technology and safety of mining.

[0007] As a further preferred embodiment of the present invention, the stripping ratio in step A=ore volume / stripping material volume, and when determining the economically reasonable stripping ratio, it needs to be calculated based on market price and mining cost factors.

[0008] As a further preferred embodiment of the present invention, the drawing of the boundary map in step B mainly includes the following steps: B1. Determine the mining depth: determine the lowest and highest mining elevations of open-pit mining according to geological conditions and mining technical requirements; B2. Determine the bottom boundary: determine the mining depth on the geological cross-section map, adjust the mine bottom elevation, and project the mining range onto the stratification plane, thereby defining the open-pit mining boundary; B3. Draw the boundary map: draw the open-pit mining boundary map on the geological stratification plan map and the sectional map, combined with the ore body occurrence conditions and the mine layout requirements.

[0009] As a further preferred embodiment of the present invention, the mining depth is determined specifically by determining the open-pit mining depth on a geological profile, and the lowest mining elevation is determined as 1405 m.

[0010] As a further preferred embodiment of the present invention, before delineating the mining boundary of the open pit, it is also necessary to determine the perimeter of the open pit bottom plane and determine the slope structure and slope.

[0011] Before defining the mining boundary of the open-pit mine, it is also necessary to determine the perimeter of the open-pit mine bottom plane. This can ensure that within the entire open-pit mining range, the ore recovery rate is the highest and the amount of rock stripping is the least; the slope structure and slope are determined because the stability of the open-pit mine slope is a necessary condition to ensure the normal production of the open-pit mine.

[0012] As a further preferred embodiment of the present invention, when drawing the open-pit mining boundary map, it is necessary to carry out the drawing on the geological stratification plan and cross-section map in combination with the ore body occurrence conditions and the stope layout requirements.

[0013] As a further preference of the present invention, the economically reasonable stripping ratio is an important indicator for delineating the boundary of open-pit mining when drawing the boundary map, and its calculation formula is usually: N=c-a / b, wherein c is the open-pit mining cost, a is the underground mining cost, and b is the open-pit stripping cost; when the open-pit mining cost is close to or higher than the underground mining cost, consider switching to underground mining; when the stripping ratio of open-pit mining is close to or higher than the economically reasonable stripping ratio, it indicates that the cost-effectiveness of continuing open-pit mining has decreased. At this time, the costs and benefits of open-pit mining and underground mining are comprehensively considered to decide whether to switch to underground mining.

[0014] As a further preferred embodiment of the present invention, in order to more accurately evaluate the cost-effectiveness of open-pit mining and underground mining, a dynamic economic analysis method is used to convert the costs of different stripping times into discounted costs based on the year of production of the open-pit mine.

[0015] As a further optimization of the present invention, the optimization adjustment is specifically carried out from the following points: (1) Economic rationality: ensuring that the average stripping ratio within the boundary is not greater than the economically reasonable stripping ratio; (2) Technical feasibility: considering the geological conditions such as the shape, thickness, inclination of the ore body, as well as mining technology, equipment selection, and slope stability technical factors; (3) Safety and environmental protection: ensuring that the boundary demarcation complies with relevant safety regulations and environmental protection standards; (4) Laws and regulations: ensuring that the mining scope complies with national laws, regulations and policy requirements.

[0016] Ensure the rationality and economy of mining scope.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. Through the above steps, detailed operations can be carried out to determine the boundary of open-pit mining to underground mining, ensuring the economy, technology and safety of mining.

[0018] 2. Before defining the mining boundary of the open-pit mine, it is also necessary to determine the perimeter of the open-pit mine bottom plane. This can ensure that within the entire open-pit mining range, the ore recovery rate is the highest and the amount of rock stripping is the least; the slope structure and slope are determined because the stability of the open-pit mine slope is a necessary condition to ensure the normal production of the open-pit mine.

[0019] 3. Optimization and adjustment can ensure the rationality and economy of mining conditions. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention described and shown herein can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Specific embodiment 1: A method for determining a reasonable boundary for converting open pit mining to underground mining is implemented by the following technical solutions: A. Calculate the stripping ratio; B. Draw the boundary map; C. Optimize and adjust; When calculating the stripping ratio, the following factors need to be considered: ore volume, stripping material volume and economically reasonable stripping ratio.

[0025] Through the above steps, detailed operations can be carried out to determine the boundary of the mine from open pit to underground mining, ensuring the economic, technical and safety of mining; The stripping ratio in step A = ore volume / stripping volume. When determining the economically reasonable stripping ratio, it needs to be calculated based on market prices and mining cost factors; The drawing of the boundary map in step B mainly includes the following steps: B1, determining the mining depth: determining the lowest and highest mining elevations of open-pit mining according to geological conditions and mining technical requirements; B2, determining the bottom boundary: determining the mining depth on the geological cross-section map, adjusting the mine bottom elevation, projecting the mining range onto the stratification plane, thereby defining the mining boundary of the open-pit mine; B3, drawing the boundary map: drawing the open-pit mining boundary map on the geological stratification plane map and the sectional map, combining the ore body occurrence conditions and the mine layout requirements; Principles for defining the boundaries of open-pit mining: Make full use of resources: confine as many ores as possible within the open-pit mining area to give full play to the advantages of open-pit mining; Ensure safe production: The final open-pit boundary slope angle should not be greater than the angle allowed by the open-pit slope stability to ensure production safety; Stripping ratio control: The boundary stripping ratio should not be greater than the economically reasonable stripping ratio to ensure economic benefits; Determining the mining depth specifically includes determining the open-pit mining depth on the geological profile map, and determining the lowest mining elevation as 1405m; Before demarcating the mining boundary of the open pit, it is also necessary to determine the perimeter of the open pit bottom plane and determine the slope structure and slope; Before defining the mining boundary of the open pit, it is also necessary to determine the perimeter of the open pit bottom plane, so as to ensure that the ore recovery rate is the highest and the amount of rock stripped is the least within the entire open pit mining range; the slope structure and slope are determined because the stability of the open pit slope is a necessary condition to ensure the normal production of the open pit; It needs to be carried out on the geological stratification plan and cross-section, combined with the ore body occurrence conditions and the requirements of the stope layout; When drawing a boundary map, the economically reasonable stripping ratio is an important indicator for delineating the boundary of open-pit mining. Its calculation formula is usually: N=c−a / b, where c is the cost of open-pit mining, a is the cost of underground mining, and b is the cost of open-pit stripping. When the cost of open-pit mining is close to or higher than the cost of underground mining, consider switching to underground mining. When the stripping ratio of open-pit mining is close to or higher than the economically reasonable stripping ratio, it indicates that the cost-effectiveness of continuing open-pit mining has decreased. At this time, the costs and benefits of open-pit and underground mining should be comprehensively considered to decide whether to switch to underground mining. In order to more accurately evaluate the cost-effectiveness of open pit and underground mining, a dynamic economic analysis method is used to convert the costs of different stripping times into discounted costs based on the year of production of the open pit mine; When determining the reasonable boundary of converting open-pit mining to underground mining, other factors should also be considered comprehensively: environmental impact: minimizing the environmental impact and damage caused by mining; Technical conditions: ensure that the technical conditions for mining boundary delineation are compatible with equipment performance; Laws and regulations: Comply with the relevant laws and regulations to ensure legality and compliance; The optimization and adjustment are specifically carried out from the following aspects: (1) Economic rationality: ensuring that the average stripping ratio within the boundary is not greater than the economically reasonable stripping ratio; (2) Technical feasibility: considering the geological conditions such as the shape, thickness, inclination, etc. of the ore body, as well as mining technology, equipment selection, and slope stability technical factors; (3) Safety and environmental protection: ensuring that the boundary demarcation complies with relevant safety regulations and environmental protection standards; (4) Laws and regulations: ensuring that the mining scope complies with national laws, regulations and policy requirements.

[0026] Ensure the rationality and economy of mining scope.

[0027] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining a reasonable boundary for converting open-pit mining to underground mining, characterized in that: This is achieved through the following technical solutions: A. Calculate the stripping ratio; B. Draw the boundary map; C. Optimize and adjust; When calculating the stripping ratio, the following factors need to be considered: ore volume, stripping material volume and economically reasonable stripping ratio.

2. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 1 is characterized in that: The stripping ratio in step A = ore volume / stripping material volume. When determining an economically reasonable stripping ratio, it needs to be calculated based on market prices and mining cost factors.

3. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 1 is characterized in that: The drawing of the boundary map in step B mainly includes the following steps: B1, determining the mining depth: determining the lowest and highest mining elevations of open pit mining according to geological conditions and mining technical requirements; B2, determining the bottom boundary: determining the mining depth on the geological cross-section map, adjusting the mine bottom elevation, projecting the mining range onto the stratified plane, thereby delineating the mining boundary of the open pit; B3. Draw a boundary map: On the geological stratification plan and cross-section, draw an open-pit mining boundary map in combination with the ore body occurrence conditions and mine layout requirements.

4. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 3 is characterized in that: The determination of the mining depth is specifically to determine the open-pit mining depth on the geological profile map, and to determine the lowest mining elevation as 1405m.

5. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 3 is characterized in that: Before defining the mining boundary of the open pit, it is also necessary to determine the perimeter of the open pit bottom plane and determine the slope structure and slope.

6. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 3 is characterized in that: When drawing the open-pit mining boundary map, it is necessary to combine the ore body occurrence conditions and mining site layout requirements on the geological stratification plan and cross-section map.

7. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 3 is characterized in that: When drawing a boundary map, the economically reasonable stripping ratio is an important indicator for delineating the boundary of open-pit mining. Its calculation formula is usually: N=c−a / b, where c is the open-pit mining cost, a is the underground mining cost, and b is the open-pit stripping cost. When the open-pit mining cost is close to or higher than the underground mining cost, consider switching to underground mining. When the stripping ratio of open-pit mining is close to or higher than the economically reasonable stripping ratio, it indicates that the cost-effectiveness of continuing open-pit mining has decreased. At this time, the costs and benefits of open-pit and underground mining should be comprehensively considered to decide whether to switch to underground mining.

8. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 4 is characterized in that: In order to more accurately evaluate the cost-effectiveness of open-pit and underground mining, a dynamic economic analysis method is used to convert the costs of different stripping times into discounted costs based on the year of production of the open-pit mine.

9. The method for determining the reasonable boundary of converting open-pit mining to underground mining according to claim 1 is characterized in that: The optimization and adjustment are specifically carried out from the following aspects: (1) Economic rationality: ensuring that the average stripping ratio within the boundary is not greater than the economically reasonable stripping ratio; (2) Technical feasibility: considering the geological conditions such as the shape, thickness, inclination, etc. of the ore body, as well as mining technology, equipment selection, and slope stability technical factors; (3) Safety and environmental protection: ensuring that the boundary demarcation complies with relevant safety regulations and environmental protection standards; (4) Laws and regulations: ensuring that the mining scope complies with national laws, regulations and policy requirements.