Open-air boundary delineation method

Abstract

The invention discloses a method for delineating an open boundary. The method comprises the following steps: R1, discretizing an ore deposit into a discrete set consisting of a plurality of discrete units; establishing a benefit calculation model according to the current ore deposit attribute; r2, taking the center of each discrete unit as a vertex one by one, selecting a slope angle with proper slope overall stability to construct a cone, and calculating open-pit mining net benefits and underground mining net benefits of all discrete units in the cone; and judging mining attributes of all discrete units in the current cone to obtain a set of exploitable discrete units. According to the method, the ore deposit is discretized, the open-pit mining net benefits and the underground mining net benefits of the discretized units are calculated respectively, and finally, the exploitable discrete unit set is obtained. The invention provides a set of proper delineation method and implementation means for delineating the boundary by comparing open-pit mining and underground mining, and maximization of the total benefit of mining is realized.

Description

Technical Field

[0001] The invention relates to a boundary delineation method, in particular to an open-pit boundary delineation method, and belongs to the technical field of mining. Background Art

[0002] Defining the open pit boundary is an essential and crucial step for both open pit mines and those transitioning from open pit to underground mining. It directly determines the amount of ore and rock within the open pit boundary, impacting the open pit mine's production scale and service life, infrastructure workload, investment, and equipment selection. It also serves as a crucial basis for mine production, operations, and decision-making. For mines transitioning from open pit to underground mining, the delineation of the open pit boundary also impacts the selection of the initial mid-section of the underground mine, the timing of the transition to underground mining, the engineering investment required for underground mining, and the safety of both open pit and underground mining, significantly impacting the production and operation of underground mines. To ensure a smooth transition from open pit to underground mining and maximize the overall benefits of both open pit and underground mining, it is essential to determine the optimal mining boundary.

[0003] Existing methods for delineating open-pit boundaries primarily utilize theories such as the LG graph theory and the floating cone method. These methods, implemented through commercial software, have greatly facilitated open-pit mining operations. However, these software programs are designed only for single open-pit mines and are not suitable for mines transitioning from open-pit to underground mining. In practice, distinguishing the boundaries between open-pit and underground mining is crucial and essential. Open-pit and underground mining are often compared, and strip ratio calculations are used to determine these boundaries. However, due to the large spatial variability in ore grades and the large variety of valuable elements, mining costs vary significantly with spatial location, and slope angles vary with factors such as lithology and elevation. Strip ratio methods cannot account for these variations. Furthermore, both LG graph theory and the floating cone method employ refined boundary delineation based on discretized small units of the ore body. Subsequently, the appropriate boundary for open-pit and underground mining is selected within a series of boundaries using inaccurate strip ratios, rendering refined boundary delineation meaningless.

[0004] As resources with relatively simple mining conditions are gradually depleted, the development of low-grade, complex, and difficult-to-mine ore bodies is gradually being put on the agenda. Delineating the boundaries of these ore bodies is becoming more challenging than ever. This is primarily due to the low geological grade of the original ore, the large proportion of low-grade ore, and the impact of surface mining on existing structures on the surface or in the rock mass, such as rivers, crushing stations, belt tunnels, goafs, roads, caves, and existing facilities. Furthermore, the comparison of open-pit and underground mining, and the impact of different mining methods in different mining areas on mining costs, make delineating the boundaries between open-pit and underground mining extremely difficult and difficult to achieve using manual empirical methods. Existing commercial software can only address the issues of single-site open-pit mining. Currently, there is still no suitable delineation method and implementation means for comparing open-pit and underground mining, especially for delineating boundaries between open-pit and underground mining under complex conditions. Therefore, it is urgent to develop a method for delineating the boundaries of open-pit and underground mining under complex conditions on the surface and in the rock mass, rationally delineate the boundaries between open-pit and underground mining, and maximize the overall benefits of open-pit and underground mining. Summary of the Invention

[0005] In view of the lack of a boundary delineation method for open-pit to underground mining projects under complex conditions in the existing technology, the present invention proposes a boundary delineation method for open-pit to underground mining. After formulating the open-pit mining boundary, the mine geological model is converted into a discrete model, and then the mining benefits of the discrete units are calculated respectively, and multiple simulated mining boundaries are set, and the total mining income of each mining boundary is calculated. Finally, the mining boundary for open-pit to underground mining is delineated, filling the gap in the existing methods and maximizing the total benefit of open-pit underground mining.

[0006] According to an embodiment of the present invention, a method for delineating an open-air boundary is provided.

[0007] A method for delineating an open-air boundary, the method comprising the following steps:

[0008] R1. Discretize the ore deposit into a discrete set consisting of multiple discrete units; establish an open-pit mining benefit estimation model and an underground mining benefit estimation model for any discrete unit based on the current ore deposit properties;

[0009] R2. Construct a cone with the center of each discrete unit as the vertex and select a slope angle that is suitable for the overall stability of the slope. Calculate the net benefits of open-pit mining and underground mining for all discrete units in the cone based on the open-pit mining benefit calculation model and the underground mining benefit calculation model. Determine the mining properties of all discrete units in the current cone based on the net benefits of open-pit mining and underground mining, and then obtain a set of mineable discrete units.

[0010] Preferably, the discrete unit in step R1 is a three-dimensional model or a two-dimensional model; preferably a hexahedron or a quadrilateral, more preferably a cube.

[0011] Preferably, the deposit attributes include basic parameters of discrete units constituting the deposit; preferably, they include geological parameters, technical parameters and economic parameters of the discrete units.

[0012] Preferably, the geological parameters include quality G, %; slope geological division Z; unit volume weight D, t / m 3 .

[0013] The technical parameters include open-pit recovery rate Rml, %; open-pit mixing rate Mml, %; underground recovery rate Rmd, %; underground mixing rate Mmd, %.

[0014] The economic parameters include open-pit unit ore mining cost A1, RMB / t; unit ore stripping cost B, RMB / t; unit grade element price P, RMB / t; underground unit ore mining cost A2, RMB / t; open-pit mining cost adjustment coefficient C1; underground mining cost adjustment coefficient C2; stripping cost adjustment coefficient C3; ore dressing cost Cp, RMB / t; ore dressing recovery rate Rp, %; other open-pit mining costs E1, RMB / t; other underground mining costs E2, RMB / t.

[0015] Preferably, the open-pit mining benefit estimation model of any discrete unit is:

[0016] The net value of open pit mining of a single discrete mineral unit, X1, is:

[0017]

[0018] Where L is the length of the discrete unit, m; W is the width of the discrete unit, m; H is the height of the discrete unit, m; D is the unit volume weight of the discrete unit, t / m 3 ; Rml is the open pit recovery rate, %; Mml is the open pit mixing rate, %; G is the discrete unit quality, %; P is the price of the unit grade element, yuan / t; Rp is the mineral processing recovery rate, %; A1 is the open pit unit ore mining cost, yuan / t; C1 is the open pit mining cost adjustment coefficient; Cp1 is the mineral processing cost of the first element in the discrete unit, yuan / t; Cp2 is the mineral processing cost of the second element in the discrete unit, yuan / t; Cp n is the beneficiation cost of the nth element in the discrete unit, RMB / t; E1 is other costs of open-pit mining, RMB / t.

[0019] The net value of open pit mining of a single discrete rock unit, X2, is:

[0020]

[0021] Where B is the unit ore stripping cost, RMB / t; C3 is the stripping cost adjustment coefficient.

[0022] The underground mining benefit calculation model of any discrete unit is:

[0023] The net value of underground mining of a single discrete mineral unit, X3, is:

[0024]

[0025] Where, Rmd is the underground recovery rate, %; Mmd is the underground mixing rate, %; A2 is the underground unit ore mining cost, yuan / t; C2 is the underground mining cost adjustment coefficient; E2 is other underground mining costs, yuan / t.

[0026] Preferably, the calculation method of the unit grade element price is:

[0027]

[0028] Where y is the price per unit weight, yuan / t; f is the grade value, %.

[0029] Preferably, the net benefit of open-pit mining of all discrete units in the cone is calculated based on the open-pit mining benefit calculation model and the underground mining benefit calculation model as follows:

[0030] Vj T =∑X1+∑X2……(Formula 5)

[0031] Where, ∑X1 is the net mining value of all open-pit mineral units within the cone, RMB; ∑X2 is the net mining value of all open-pit rock units within the cone, RMB.

[0032] Preferably, the mining attributes of all discrete units in the current cone are determined based on the net benefits of open-pit mining and underground mining, and the set of mineable discrete units is obtained as follows:

[0033] When Vjl is calculated by Equation 4 T When ≤0, open-pit mining is not carried out;

[0034] When Vjl is calculated by Equation 4 T When >0, calculate the sum of the mining value of all underground mineral units within the cone:

[0035] The net benefit of underground mining for all discrete units within the cone is calculated based on the open-pit mining benefit calculation model and the underground mining benefit calculation model:

[0036] Vj X =∑X3……(Formula 6)

[0037] Where ∑X3 is the net mining value of all underground mineral units in the cone, yuan.

[0038] When Vjl is calculated by Equation 5 and Equation 6 T >Vjl X When , all discrete units in the cone can be mined in open pits. All discrete units in the cone are marked as 1, and all discrete units marked as 1 are the set of mineable discrete units.

[0039] When Vjl is calculated by Equation 5 and Equation 6 T =Vjl X When , all discrete units in the cone can be mined in the open pit or underground.

[0040] When Vjl is calculated by Equation 5 and Equation 6 T <Vjl X When , all discrete units within the cone can be mined underground.

[0041] Preferably, the method further comprises:

[0042] R3: Construct a simulated mining boundary with the center of each discrete unit as the vertex, calculate the number of mineable units in each simulated mining boundary, and obtain the optimal mining boundary by statistics.

[0043] Preferably, step R3 is specifically as follows: each time, a cone-shaped simulated mining boundary is constructed with the center of different discrete units as the vertex, the number of open-pit mining units in each simulated mining boundary is counted, and then the number of mineable units counted each time is compared with the number of mineable units counted last time. When the number of mineable units counted twice is equal, the open-pit mining units in this simulated mining boundary are output. After all the simulated mining boundaries with the centers of different discrete units as the vertex components are counted, all open-pit mining units are output, that is, the optimal mining boundary.

[0044] In the present invention, by discretizing the ore deposit and calculating them separately, the open-pit mining benefit estimation model and the underground mining benefit estimation model of each discrete unit are obtained, and then a cone is constructed one by one with the center of each discrete unit as the vertex combined with the slope angle, and the net benefits of open-pit mining and underground mining of all discrete units in the cone are calculated, and finally a set of mineable discrete units is obtained. The present invention reasonably delineates the mining boundary, and delineates the boundary by comparing open-pit mining and underground mining, especially the boundary delineation of open-pit to underground mining under complex conditions. A set of appropriate delineation methods and implementation means are proposed to maximize the total mining benefit.

[0045] In the present invention, the discrete model can be either a three-dimensional model or a two-dimensional model, wherein the two-dimensional model must be on a vertical plane. Furthermore, in establishing the open-pit mining and underground mining benefit estimation models for any discrete unit, the present invention calculates various parameters, including geological, technical, and economic parameters, particularly various costs such as quality, unit volume weight, mining cost, mineral processing recovery rate, and cost adjustment coefficients, to ensure the accuracy and comprehensiveness of the models, thereby accurately comparing the net benefits of open-pit and underground mining.

[0046] In the present invention, further, the mining benefits of each simulated mining state calculated with the center of each discrete unit as the vertex can be compared to obtain the mining state with the best benefits, so as to achieve the best mining benefit.

[0047] In the present invention, the component discrete model software can be a three-dimensional visualization software, preferably any one of AUTOCAD, DIMINE, SURPAC, 3DMINE, and MICROMINE. In addition, the slope angle suitable for the overall stability of the slope described in step R2 can be calculated by the method described in CN117669120A.

[0048] In the present invention, whether the units divided by the slope line are included in the calculation is distinguished in the following way: if the center of a unit is within the cone range, the unit is calculated; if the center of the unit is not within the cone range, the unit is not calculated.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. This invention provides a method for delineating open-pit boundaries. By discretizing a mineral deposit and separately calculating the net benefits of open-pit mining and underground mining for each discrete unit, a set of mineable discrete units is ultimately obtained. A suitable delineation method and implementation approach are proposed for comparing open-pit and underground mining boundaries, maximizing the overall mining benefit.

[0051] 2. The method for delineating open-pit boundaries provided by the present invention fully considers multiple parameters including geological parameters, technical parameters and economic parameters, ensuring the accuracy and comprehensiveness of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the discrete set map obtained after discretizing the mineral deposit in Example 1.

[0053] Figure 2 This is a discrete set diagram including the net mining value of each discrete unit in Example 1.

[0054] Figure 3A discrete set graph of a cone is constructed with the center of the 30th unit as the vertex in Example 1.

[0055] Figure 4 This is the optimal efficiency mining boundary diagram in Example 2. DETAILED DESCRIPTION

[0056] The technical solutions of the present invention are illustrated below with examples, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0057] Example 1

[0058] According to an embodiment of the present invention, a method for delineating an open-air boundary is provided.

[0059] A method of defining the open-air realm:

[0060] R1. Discretize the ore deposit into a discrete set consisting of cubes with a side length of 1m (see Figure 1 ), the shaded part represents the mineral unit, and the blank part represents the rock unit; the value of quality G is shown in the figure (i.e. the value of grade in the figure), and the unit volume weight D is 2.7t / m 3 ;

[0061] The technical parameters include open pit recovery rate Rml, which is 0.95; open pit mixing rate Mml, which is 0.05; underground recovery rate Rmd, which is 0.9; underground mixing rate Mmd, which is 0.1;

[0062] The unit cost of open-pit ore mining A1 is determined according to the properties of each unit; the unit ore stripping cost B is 8 yuan / t; the unit grade element price P is yuan / t, and the price of 58% grade iron ore concentrate is 500 yuan / t; the unit ore mining cost A2 of underground ore is 34 yuan / t; the open-pit mining cost adjustment coefficient C1 is 1; the underground mining cost adjustment coefficient C2 is 1; the stripping cost adjustment coefficient C3 is 1; the mineral processing cost Cp is 10 yuan / t; the mineral processing recovery rate Rp is 60%; other costs of open-pit mining E1 are 2 yuan / t; other costs of underground mining E2 are 1 yuan / t.

[0063] Establish a model for estimating the benefits of open-pit mining for any discrete unit:

[0064] Net value of open pit mining of a single discrete mineral unit X1:

[0065]

[0066] Net value of open pit mining of a single discrete rock unit X2:

[0067]

[0068] It can be obtained that the unit with serial number 1 is a discrete rock unit, and the net value is calculated as follows:

[0069]

[0070] Unit number 5 is a discrete mineral unit, and its net value is calculated as follows:

[0071]

[0072] Unit number 7 is a discrete mineral unit, and its net value is calculated as follows:

[0073]

[0074] The calculation process of the net value of open-pit mining for the remaining units is similar.

[0075] A model for estimating the underground mining benefits of any discrete mineral unit is established:

[0076]

[0077] Unit number 5 is a discrete mineral unit, and its net value is calculated as follows:

[0078]

[0079] Unit number 7 is a discrete mineral unit, and its net value is calculated as follows:

[0080]

[0081] The calculation process of the net value of underground mining of other mineral units is similar, and the final results are as follows: Figure 2 .

[0082] R2. Construct a cone with the center of each discrete unit as the vertex and select a slope angle that is suitable for the overall stability of the slope, and determine whether it is mineable.

[0083] First, determine whether the cone with the center of the first unit as the vertex is mineable:

[0084] A cone is constructed with the center of the first unit as the vertex and a slope angle of 45° as the cone angle. The net value of open-pit mining of all mineral units within the cone is:

[0085] ∑X1=0

[0086] The net sum of open pit mining for all open pit rock units within the cone is:

[0087] ∑X2=-21.6

[0088] Then we have:

[0089] Vj T =∑X1-∑X2=-21.6

[0090] Vj T <0, the ore body within the cone cannot be mined.

[0091] The judgment is to construct a cone with the center of the fifth unit as the vertex and the slope angle of 45° as the cone angle. The net value of open-pit mining of all mineral units in the cone is:

[0092] ∑X1=70.56

[0093] The net sum of open pit mining for all open pit rock units within the cone is:

[0094] ∑X2=0

[0095] Then we have:

[0096] Vj T =∑X1-∑X2=70.56

[0097] Further calculation of the value of all mineral units in the cone when mined underground:

[0098] Vj X =∑X3=1.48

[0099] Vj T >Vjl X , all discrete units in the cone can be mined in open pits, and all discrete units in the cone are marked as 1.

[0100] A cone is constructed with the center of the 30th unit as the vertex and a slope angle of 45° as the cone angle. The net value of open-pit mining of all mineral units within the cone is:

[0101] ∑X1=70.56

[0102] The net sum of open pit mining for all open pit rock units within the cone is:

[0103] ∑X2=-43.2

[0104] Then we have:

[0105] Vj T =∑X1+∑X2=27.36

[0106] Further calculation of the value of all mineral units in the cone when mined underground:

[0107] Vj X =∑X3=1.48

[0108] Vj T >Vjl X, all discrete units in the cone can be mined in open pits, and all discrete units in the cone are marked as 1.

[0109] A cone is constructed with the center of the 40th unit as the vertex and a slope angle of 45° as the cone angle. The net value of open-pit mining of all mineral units within the cone is:

[0110] ∑X1=17.5

[0111] The net sum of open pit mining for all open pit rock units within the cone is:

[0112] ∑X2=-237.6

[0113] Then we have:

[0114] Vj T =∑X1+∑X2=-220.1

[0115] Because Vjl T When ≤0, open-pit mining is not carried out.

[0116] According to the above method, the cone vertex is moved to all units in turn to determine whether they can be mined, and finally all minable boundaries are obtained (such as the cone constructed with the center of the 30th unit, the 31st unit, etc. as the vertex and the slope angle of 45° as the cone angle).

[0117] Example 2

[0118] Repeat Example 1, except that it also includes:

[0119] R3: Starting from the cell numbered 1, each time the center of a different discrete cell is used as the vertex, a cone-shaped simulated mining boundary is constructed. The number of open-pit mining units in the simulated mining boundary with the center of cell No. 1 as the vertex is 0, the number of open-pit mining units in the simulated mining boundary with the center of cell No. 2 as the vertex is 0, ..., the number of open-pit mining units in the simulated mining boundary with the center of cell No. 5 as the vertex is 1, the number of open-pit mining units in the simulated mining boundary with the center of cell No. 6 as the vertex is 1, and the open-pit mining units in the simulated mining boundary No. 6 are output; ...; the number of open-pit mining units in the simulated mining boundary with the center of cell No. 30 as the vertex is 7, the number of open-pit mining units in the simulated mining boundary with the center of cell No. 31 as the vertex is 7, and the open-pit mining units in the simulated mining boundary No. 31 are output. After all the simulated mining boundaries with the centers of different discrete cells as the vertex components are counted, all open-pit mining units are output, that is, the optimal mining boundary (such as Figure 4 ).

Claims

1. A method for delineating an open-air boundary, characterized by: The method comprises the following steps: R1. Discretize the ore deposit into a discrete set consisting of multiple discrete units; establish an open-pit mining benefit estimation model and an underground mining benefit estimation model for any discrete unit based on the current ore deposit properties; R2. Construct a cone with the center of each discrete unit as the vertex and select a slope angle that is suitable for the overall stability of the slope. Calculate the net benefits of open-pit mining and underground mining for all discrete units in the cone based on the open-pit mining benefit calculation model and the underground mining benefit calculation model. Determine the mining properties of all discrete units in the current cone based on the net benefits of open-pit mining and underground mining, and then obtain a set of mineable discrete units.

2. The method according to claim 1, wherein: The discrete unit described in step R1 is a three-dimensional model or a two-dimensional model; preferably a hexahedron or a quadrilateral, more preferably a cube.

3. The method according to claim 1 or 2, characterized in that: The mineral deposit attributes include basic parameters of the discrete units constituting the mineral deposit; preferably, the basic parameters include geological parameters, technical parameters and economic parameters of the discrete units; Preferably, the geological parameters include quality G, %; slope geological division Z; unit volume weight D, t / m 3 ; The technical parameters include open pit recovery rate Rml, %; open pit mixing rate Mml, %; underground recovery rate Rmd, %; underground mixing rate Mmd, %; The economic parameters include open-pit unit ore mining cost A1, RMB / t; unit ore stripping cost B, RMB / t; unit grade element price P, RMB / t; underground unit ore mining cost A2, RMB / t; open-pit mining cost adjustment coefficient C1; underground mining cost adjustment coefficient C2; stripping cost adjustment coefficient C3; ore dressing cost Cp, RMB / t; ore dressing recovery rate Rp, %; other open-pit mining costs E1, RMB / t; other underground mining costs E2, RMB / t.

4. The method according to claim 3, wherein: The open-pit mining benefit calculation model of any discrete unit is: The net value of open pit mining of a single discrete mineral unit, X1, is: Where L is the length of the discrete unit, m; W is the width of the discrete unit, m; H is the height of the discrete unit, m; D is the unit volume weight of the discrete unit, t / m 3 ; Rml is the open pit recovery rate, %; Mml is the open pit mixing rate, %; G is the discrete unit quality, %; P is the price of the unit grade element, yuan / t; Rp is the mineral processing recovery rate, %; A1 is the open pit unit ore mining cost, yuan / t; C1 is the open pit mining cost adjustment coefficient; Cp1 is the mineral processing cost of the first element in the discrete unit, yuan / t; Cp2 is the mineral processing cost of the second element in the discrete unit, yuan / t; Cp n is the beneficiation cost of the nth element in the discrete unit, RMB / t; E1 is other costs of open pit mining, RMB / t; The net value of open pit mining of a single discrete rock unit, X2, is: Where, B is the unit ore stripping cost, RMB / t; C3 is the stripping cost adjustment coefficient; The underground mining benefit calculation model of any discrete unit is: The net value of underground mining of a single discrete mineral unit, X3, is: Where, Rmd is the underground recovery rate, %; Mmd is the underground mixing rate, %; A2 is the underground unit ore mining cost, yuan / t; C2 is the underground mining cost adjustment coefficient; E2 is other underground mining costs, yuan / t.

5. The method according to claim 4, characterized in that: The calculation method of the unit grade element price is: Where y is the price per unit weight, yuan / t; f is the grade value, %.

6. The method according to any one of claims 3 to 5, characterized in that: The net benefit of open-pit mining for all discrete units within the cone is calculated based on the open-pit mining benefit calculation model and the underground mining benefit calculation model: Vj T =∑X1+∑X2……(Formula 5) Where, ∑X1 is the net mining value of all open-pit mineral units within the cone, RMB; ∑X2 is the net mining value of all open-pit rock units within the cone, RMB.

7. The method according to claim 6, characterized in that: The mining attributes of all discrete units in the current cone are determined based on the net benefits of open-pit mining and underground mining, and the set of mineable discrete units is obtained as follows: When Vjl is calculated by Equation 4 T When ≤0, open-pit mining is not carried out; When Vjl is calculated by Equation 4 T When >0, calculate the sum of the mining value of all underground mineral units within the cone: The net benefit of underground mining for all discrete units within the cone is calculated based on the open-pit mining benefit calculation model and the underground mining benefit calculation model: Vj X =∑X3……(Formula 6) Where, ∑X3 is the net value of mining of all underground mineral units in the cone, yuan; When Vjl is calculated by Equation 5 and Equation 6 T >Vjl X When , all discrete units in the cone can be mined in open pits, and all discrete units in the cone are marked as 1. All discrete units marked as 1 are the set of mineable discrete units. When Vjl is calculated by Equation 5 and Equation 6 T =Vjl X When , all discrete units in the cone can be mined in open pits or underground; When Vjl is calculated by Equation 5 and Equation 6 T <Vjl X When , all discrete units within the cone can be mined underground.

8. The method according to any one of claims 1 to 7, characterized in that: The method further includes: R3: Construct a simulated mining boundary with the center of each discrete unit as the vertex, calculate the number of mineable units in each simulated mining boundary, and obtain the optimal mining boundary by statistics.

9. The method according to claim 8, characterized in that: Step R3 is specifically as follows: each time, a cone-shaped simulated mining boundary is constructed with the center of different discrete units as the vertex, and the number of open-pit mining units in each simulated mining boundary is counted, and then the number of mineable units counted each time is compared with the number of mineable units counted last time. When the number of mineable units counted twice is equal, the open-pit mining units in this simulated mining boundary are output. After all the simulated mining boundaries with the centers of different discrete units as the vertex components are counted, all open-pit mining units are output, that is, the optimal mining boundary.

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