Metal mine saturated ore rock blasting hole net parameter determination method considering moisture content influence

Abstract

The invention discloses a metal mine saturated ore rock blasting hole net parameter determination method considering the influence of water content, and relates to the field of mine blasting, and the method comprises the following steps: determining a damage reduction coefficient based on the water content of ore rock in a main blasting area; calculating the hole pitch of the main blasting holes and the row pitch of the main blasting holes based on the damage reduction coefficient; if all the ore rocks in the main blasting area are in the saturated state, or one part of the ore rocks are in the saturated state and the other part of the ore rocks are in the normal state, the explosive load of each blast hole in the main blasting area is calculated based on the damage reduction coefficient, the blasting effect can be improved, and then the blasting efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of mine blasting, and particularly to a method for determining blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of moisture content. Background Art

[0002] During the process of mine exploitation, blasting is the main means of crushing ore and rock, and the blasting effect directly affects the production efficiency and economic benefits of the mine. Traditional methods for calculating blast hole pattern parameters usually rely on empirical formulas or numerical simulations, taking into account parameters such as the mechanical properties, integrity coefficient, and fracture characteristics of rocks, but ignoring other parameters. As a result, when blasting according to these blast hole pattern parameters, the blasting effect is not ideal, leading to low final blasting efficiency. Summary of the Invention

[0003] The purpose of this application is to provide a method for determining blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of moisture content, which can improve the blasting effect and thus enhance the blasting efficiency.

[0004] To achieve the above purpose, this application provides the following solutions:

[0005] This application provides a method for determining blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of moisture content. The blast hole pattern parameters include the hole spacing of the main blast holes, the row spacing of the main blast holes, and the charge amount of the blast holes. The method for determining blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of moisture content includes:

[0006] Determine the damage reduction coefficient based on the moisture content of the ore and rock in the main blast area;

[0007] Calculate the hole spacing of the main blast holes and the row spacing of the main blast holes based on the damage reduction coefficient;

[0008] If all the ore and rock in the main blast area are in a saturated state, or part of the ore and rock is in a saturated state and the other part is in a normal state, then calculate the charge amount of each blast hole in the main blast area based on the damage reduction coefficient.

[0009] In one embodiment, the method for determining blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of moisture content further includes:

[0010] If all the ore and rock in the main blast area are in a normal state, then calculate the charge amount of each blast hole in the main blast area according to the hole spacing of the main blast holes and the row spacing of the main blast holes.

[0011] In one embodiment, determining the damage reduction coefficient based on the moisture content of the ore and rock in the main blast area specifically includes:

[0012] Calculate the rock saturation coefficient based on the moisture content of the ore and rock in the main blast area and the saturated moisture content;

[0013] Determine the damage reduction coefficient based on the rock saturation coefficient.

[0014] In one embodiment, calculating the hole spacing and row spacing of the main blasting holes based on the damage reduction coefficient specifically includes:

[0015] Calculating the hole spacing of the main blasting holes according to the damage reduction coefficient, the bottom resistance line of the blast holes in the main blasting area, and the hole density coefficient;

[0016] Calculating the row spacing of the main blasting holes according to the damage reduction coefficient, the hole spacing of the main blasting holes, and the burden area of the blast holes.

[0017] In one embodiment, calculating the charge amount of each blast hole in the main blasting area based on the damage reduction coefficient specifically includes:

[0018] If all the ore and rock in the area where the explosive is located are in a fully saturated state, then calculate the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the damage reduction coefficient, the hole spacing of the main blasting holes, the bench height, the bottom resistance line of the blast holes in the main blasting area, and the unit explosive consumption; calculate the charge amount of each blast hole other than the first row of blast holes in multi-row blasting according to the damage reduction coefficient, the hole spacing of the main blasting holes, the row spacing of the main blasting holes, the unit explosive consumption, the bench height, and the ore and rock resistance increase coefficient;

[0019] If part of the ore and rock in the area where the explosive is located is in a fully saturated state and the other part is in a normal state, then calculate the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the water depth in the blast hole, the explosive depth in the blast hole, the damage reduction coefficient, the hole spacing of the main blasting holes, the bench height, the bottom resistance line of the blast holes in the main blasting area, and the unit explosive consumption; calculate the charge amount of each blast hole other than the first row of blast holes in multi-row blasting according to the water depth in the blast hole, the explosive depth in the blast hole, the damage reduction coefficient, the hole spacing of the main blasting holes, the row spacing of the main blasting holes, the unit explosive consumption, the bench height, and the ore and rock resistance increase coefficient.

[0020] In one embodiment, calculating the charge amount of each blast hole in the main blasting area according to the hole spacing and row spacing of the main blasting holes specifically includes:

[0021] Calculating the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the hole spacing of the main blasting holes, the bench height, the bottom resistance line of the blast holes in the main blasting area, and the unit explosive consumption;

[0022] Calculating the charge amount of each blast hole other than the first row of blast holes in multi-row blasting according to the hole spacing of the main blasting holes, the row spacing of the main blasting holes, the unit explosive consumption, the bench height, and the ore and rock resistance increase coefficient.

[0023] According to the specific embodiments provided in the present application, the present application has the following technical effects:

[0024] The present application provides a method for determining the parameters of blasting hole network for saturated ore rock in metal mines taking into account the influence of water content. Some mines have special geological conditions, large underground water inflow, and the rock mass has been soaked in groundwater for a long time. The free water content inside is high, and it is even in a saturated state. Water plays an important role in controlling the strength of rock and is an important factor that cannot be ignored. There are a large number of initial defects in the rock mass, such as voids, pores, microcracks and joints. The existence of these defects increases the contact between water and rock mass, thereby changing the mechanical properties and deformation characteristics of the rock mass. On the one hand, the mechanical properties of the rock are degraded or weakened due to the corrosive effect of water on the rock mass. On the other hand, the hydraulic action will also have a certain influence on the fracture mechanics properties of the rock mass. In the traditional method of calculating the parameters of the blasting hole network, the influence of water content is often ignored. However, the moisture content of ore rock is one of the important factors affecting the blasting effect. The change of moisture content will change the physical and mechanical properties of ore rock, and then affect the propagation of blasting stress wave, the expansion of cracks and the distribution of blasting block size, resulting in unsatisfactory blasting effect, high block rate, many roots, large blasting vibration and other problems, which in turn affect the blasting efficiency. This application first determines the damage reduction coefficient based on the moisture content of ore rock in the main blasting area, and then calculates the blasting hole network parameters based on the damage reduction coefficient. The moisture content is taken into account in the process of calculating the blasting hole network parameters, which can improve the blasting effect, reduce the large block rate, and reduce the later crushing cost, thereby improving the blasting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A flow chart of a method for determining hole pattern parameters for blasting saturated rock in a metal mine taking into account the influence of water content provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the process of determining the main blasthole spacing and the main blasthole row spacing;

[0028] Figure 3 This is a schematic diagram of the ore and rock status in the main blasting area;

[0029] Figure 4 Schematic diagram of four water-bearing states of ore rocks in the main blasting area;

[0030] Figure 5 The three-dimensional reconstruction images of dry, natural and saturated specimens after blasting;

[0031] Figure 6It is a schematic diagram of regional segmentation;

[0032] Figure 7 It is a schematic diagram of the crack conditions in each area of the specimen after blasting;

[0033] Figure 8 It is a schematic diagram of the fractal dimension of each area;

[0034] Figure 9 It is a schematic diagram of the water content in the saturated state and the natural state;

[0035] Figure 10 It is a schematic diagram of the Stefan effect;

[0036] Figure 11 It is a schematic diagram of the meniscus effect;

[0037] Figure 12 It is a schematic diagram of the internal free water state of the ore specimen in the dry state and the natural state. Specific implementation manners

[0038] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0039] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0040] In an exemplary embodiment, as Figure 1 shown, a method for determining the blast hole pattern parameters of saturated ore and rock in a metal mine considering the influence of water content is provided. The method for determining the blast hole pattern parameters of saturated ore and rock in a metal mine considering the influence of water content includes the following steps 201 to step 203. The blast hole pattern parameters include the hole spacing of the main blast holes, the row spacing of the main blast holes, and the charge amount of the blast holes. Blasting can be carried out according to the blast hole pattern parameters during blasting, where:

[0041] Step 201: Determine the damage reduction coefficient based on the water content of the ore and rock in the main blast area.

[0042] Step 202: Calculate the hole spacing of the main blast holes and the row spacing of the main blast holes based on the damage reduction coefficient.

[0043] Step 203: If all the ore and rock in the main blast area is in a saturated state, or part of the ore and rock is in a saturated state and the other part is in a normal state, then calculate the charge amount of each blast hole in the main blast area based on the damage reduction coefficient.

[0044] Implement the above steps 201 to 203. First, determine the damage reduction coefficient based on the moisture content of the ore and rock in the main blasting area, and then calculate the blasting hole pattern parameters based on the damage reduction coefficient. Considering the moisture content in the process of calculating the blasting hole pattern parameters, it is possible to optimize the blasting hole pattern parameters according to the ore and rock characteristics under different moisture content conditions, achieve precise blasting, improve the blasting effect, and thus improve the blasting efficiency.

[0045] In another exemplary embodiment of the present application, before step 201, it further includes: testing the moisture content of the ore and rock. Specifically, collect the ore and rock samples in the main blasting area and test the moisture content and saturated moisture content of the ore and rock. The steps are as follows:

[0046] Use a core drilling and sampling device to take samples in the main blasting area. The sampling depth shall not be lower than the depth of the blast hole. The core samples obtained on site are arranged according to the position of the drilling depth, and the ore and rock in a total of 3 regions, namely the middle and both ends, are taken, the surface moisture is wiped dry, and immediately wrapped with plastic wrap to ensure that the moisture content does not change.

[0047] Break the obtained core samples with a hammer, take 6 - 8 appropriately sized ore fragments, and divide them into two groups, A and B, equally. For group A specimens, first weigh the wet mass m s of each ore fragment, and then put it into an oven at a temperature of 105°C - 110°C and weigh it every 12 hours until the weight no longer changes. Immediately transfer the sample to a desiccator after drying and cool it to room temperature (about 30 minutes), and weigh its dry mass m g . Calculate its moisture content w using the mass difference before and after drying. The calculation formula is Repeat three times for each group of specimens and take the average value.

[0048] Place the specimens in group B in water, with the water surface covering the surface of the specimens and soak for 48 hours. After 48 hours, weigh the specimens every 12 hours (wipe the surface moisture dry when weighing) until the weight of the specimens no longer changes, and weigh the weight m b at this time. Then place the specimens in an oven at a temperature of 105°C - 110°C and weigh them every 12 hours until the weight no longer changes. Immediately transfer the sample to a desiccator after drying and cool it to room temperature (about 30 minutes), and weigh its dry mass m bg . Calculate its saturated moisture content w b using the mass difference before and after drying. The calculation formula is Repeat three times for each group of specimens and take the average value.

[0049] In another exemplary embodiment of the present application, step 201 specifically includes:

[0050] Calculate the rock saturation coefficient β based on the moisture content and saturated moisture content of the ore and rock in the main blasting area. The specific formula is: Generally, the value of β ranges from 0 to 1.

[0051] Determine the damage reduction coefficient η based on the rock water saturation coefficient. The specific formula is as follows: η is the damage reduction coefficient considering the water content. Different mines use different formulas for the hole spacing and row spacing. η is a reduction based on them and is not limited to a certain formula. The formula for determining η here is for mines in a rich water environment.

[0052] In another exemplary embodiment of the present application, step 202 specifically includes:

[0053] Calculate the main blast hole spacing a according to the damage reduction coefficient, the bottom resistance line of the main blast area holes, and the hole density coefficient. w 。

[0054] Calculate the main blast hole row spacing b according to the damage reduction coefficient, the main blast hole spacing, and the hole burden area. w 。

[0055] Figure 2 is a schematic diagram of the determination process of the main blast hole spacing and the main blast hole row spacing. Figure 2 Part (a) in is a schematic diagram of the determination process of the main blast hole spacing and the main blast hole row spacing under a high water saturation coefficient. Figure 2 Part (b) in is a schematic diagram of the determination process of the main blast hole spacing and the main blast hole row spacing under a medium water saturation coefficient. Figure 2 Part (c) in is a schematic diagram of the determination process of the main blast hole spacing and the main blast hole row spacing under a low water saturation coefficient. Based on this, the present application introduces η on the basis of the conventional hole pattern parameter calculation formula to obtain the main blast hole spacing a w and the main blast hole row spacing b w , where a w =ηmW1, S w =a w ×b w =ηS. In the formula: W1 is the bottom resistance line of the main blast area holes, m represents the hole density coefficient (the ratio of the hole spacing to the row spacing), generally m = 1.2 - 1.5, S is the hole burden area (determined according to the hole diameter), in square meters; S w is the hole burden area considering the water content, in square meters.

[0056] In another exemplary embodiment of the present application, the bottom resistance line of the main blast area holes is calculated according to the formula . In the formula: d is the hole diameter, in meters; Δ is the charge density, kg / m 3 ; τ is the charge coefficient, τ = 0.35 - 0.65; q is the unit explosive consumption, kg / m 3 .

[0057] In practical applications, with the deepening of ore and rock mining, in deep open-pit mines in a rich water environment, the blasting depth can reach 400 m below the original ground surface. At this depth, the groundwater is abundant, the water content in the blast holes of each main blasting area is rich, and the water content states of the holes in the main blasting area are close, and the properties of the ore and rock are not very different. Unless it is an extremely large blasting area, it is very difficult to have a situation where one blast hole contains water and the surrounding ore and rock is in a saturated state, while another blast hole does not contain water and the surrounding ore and rock is in an unsaturated state. As Figure 3 shown, when blasting in the main blasting area, there is a certain amount of accumulated water in the hole. It is considered that the ore and rock below the water surface of the accumulated water in the hole is saturated ore and rock, and the water content of the rock mass above the water surface is lower than that of the saturated ore and rock, and it is regarded as normal ore and rock. In the design of the charging structure in the traditional main blasting area, if the water content state of the ore and rock is considered, there are three different situations as Figure 4 shown: Figure 4 In part (a), all the ore and rock is in a saturated state. Figure 4 In part (b), some of the ore and rock is in a saturated state, and the explosive is located in the saturated ore and rock area. Figure 4 In part (c), some of the ore and rock is in a saturated state, and the explosive is partly located in the normal rock mass area and partly located in the saturated rock mass area. Figure 4 In part (d), all the ore and rock is in the state of normal rock mass. Based on this, in another exemplary embodiment of the present application, step 203 specifically includes:

[0058] If all the ore and rock in the area where the explosive is located is in a saturated state, as Figure 4 shown in part (a) and Figure 4 shown in part (b), then according to the damage reduction coefficient, the hole spacing of the main blast holes, the bench height, the bottom resistance line of the blast holes in the main blasting area, and the unit explosive consumption, calculate the charge amount Q1 of each blast hole in single-row blasting or the charge amount Q1' of each blast hole in the first row of blast holes in multi-row blasting. The specific calculation formula is where H represents the bench height, and the unit is meter.

[0059] According to the damage reduction coefficient, the hole spacing of the main blast holes, the row spacing of the main blast holes, the unit explosive consumption, the bench height, and the ore and rock resistance increase coefficient, calculate the charge amount of each blast hole except the first row of blast holes in multi-row blasting. The specific calculation formula is where k represents the ore and rock resistance increase coefficient, which is the ore and rock resistance increase coefficient considering the front row of each hole, and the value of k is 1.1 - 1.2.

[0060] If part of the ore and rock in the area where the explosive is located is in a saturated state and the other part is in a normal state, as Figure 4As shown in part (c), calculate the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the water depth in the blast hole, the depth of explosive in the blast hole, the damage reduction coefficient, the hole spacing of main blast holes, the bench height, the bottom resistance of blast holes in the main blasting area, and the unit explosive consumption. The specific calculation formula is Wherein, l1 represents the water depth in the blast hole, and l2 represents the depth of explosive in the blast hole.

[0061] Calculate the charge amount of each blast hole except the first row of blast holes in multi-row blasting according to the water depth in the blast hole, the depth of explosive in the blast hole, the damage reduction coefficient, the hole spacing of main blast holes, the row spacing of main blast holes, the unit explosive consumption, the bench height, and the coefficient of increase in ore and rock resistance. The specific calculation formula is

[0062] In another exemplary embodiment of the present application, the method for determining the blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of moisture content further includes:

[0063] Step 204: If all the ore and rock in the main blasting area are in a normal state, calculate the charge amount of each blast hole in the main blasting area according to the hole spacing of main blast holes and the row spacing of main blast holes, as Figure 4 shown in (d).

[0064] In another exemplary embodiment of the present application, step 204 specifically includes:

[0065] Calculate the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the hole spacing of main blast holes, the bench height, the bottom resistance of blast holes in the main blasting area, and the unit explosive consumption. The specific calculation formula is Q1 = Q1' = q · a w ·W1·H.

[0066] Calculate the charge amount of each blast hole except the first row of blast holes in multi-row blasting according to the hole spacing of main blast holes, the row spacing of main blast holes, the unit explosive consumption, the bench height, and the coefficient of increase in ore and rock resistance. The specific formula is Q2 = k · q · a w ·b w ·H.

[0067] The present application can be widely applied to blasting engineering in various mines such as metal mines, non-metal mines, and coal mines.

[0068] The design principle of the above embodiments of the present application is as follows:

[0069] Hematite samples were used to prepare three types of specimens: dry state (water content 0%), natural state (water content 0.33%), and saturated water state (water content 1.67%). A hole was drilled in the middle of the specimen, and a blasting test was carried out using 75 mg of lead azide. After the test, CT scanning was performed, and the scanned slices were reconstructed three-dimensionally. The reconstructed diagram is as shown in Figure 5 shown, Figure 5 where part (a) in Figure 5 is the reconstructed diagram corresponding to the dry state, Figure 5 part (b) in

[0070] is the reconstructed diagram corresponding to the natural state, and part (c) in

[0071] is the reconstructed diagram corresponding to the saturated water state. The expansion of blasting cracks is roughly divided into three stages: Ⅰ. The stage of the action of blasting stress waves. In this stage, the specimen is subjected to stress waves, and cracks are generated due to the rupture of the specimen. Ⅱ. The stage of the action of explosion-generated gases. In this stage, the explosion-generated gases are filled into the cracks formed in the stage of the action of blasting stress waves and expand to drive the cracks to continuously expand outward until the cracks penetrate. Ⅲ. The stage of the action of inertial forces. After the radial cracks penetrate to the outside, a connected channel appears between the inside and the outside of the specimen. The explosion-generated gases in this channel are the least hindered, so the explosion-generated gases inside the specimen quickly escape from here. After that, the crack expansion of the specimen mainly depends on the action of inertial forces, and the cracks gradually stop moving as the inertial forces weaken. Figure 6 shown, the specimens were divided into regions as shown in Figure 7 shown, Figure 7 where part (a) in Figure 7 is the three-dimensional crack situation of each region in the dry state, Figure 7 part (b) in Figure 8 is the three-dimensional crack situation of each region in the natural state, and part (c) in

[0072] is the three-dimensional crack situation of each region in the saturated water state. Through calculation, the fractal dimensions of the overall damage of the specimens in the dry, natural, and saturated water states are 2.25, 2.29, and 2.14 respectively. The three-dimensional fractal dimensions of each region are as shown in

[0073] In areas ① and ②, the damage degrees of the specimens in groups A and B are not much different, while the damage degree of the specimens in group C shows a rapid decrease. The damage degree of group C is relatively reduced by 4.11% and 1.35% compared with that of group B. In areas ④ and ⑤, both groups A and C show a certain degree of reduction compared with group B, and again, the reduction speed of group C is faster. Group C is relatively reduced by 12.16% and 20.83% compared with group B, while group B is reduced by 4.05% and 11.11%.

[0074] The crack propagation in areas ① - ③ mainly includes two stages, Ⅰ and Ⅱ, and the crack propagation in areas ④ and ⑤ mainly includes three stages, Ⅰ - Ⅲ. Figure 8 It can be seen that the difference between the specimens in the saturated water state and the natural state in areas ④ and ⑤ is the largest. Therefore, it can be obtained that the influence of the water content state on crack propagation mainly acts in the third stage. For the specimens in the saturated water state, the overall damage is reduced by 6.55%, and the damage in each area is reduced by 1.35% - 20.83%. To ensure the blasting effect, the overall damage reduction is taken as 10%.

[0075] Analysis of the principle of damage reduction: In open - pit metal mines, the internal structures of the ore rocks in the saturated water state and the natural state in the same main blasting area are the same as a whole, and only the difference in the free water content exists. Taking the hematite in the Shougang Qian'an Shuichang Iron Mine as an example, the water content rate of the ore rock in the saturated water state is 1.67%, and the water content rate of the ore rock in the natural state is 0.33%. The solid part of the ore rock material can be regarded as many plates, and the free water in the defects can be regarded as an incompressible liquid between the plates. Therefore, it can be considered that the free water in the internal defects of the rock mass under the two water - content states is in the state as Figure 9 shown. Figure 9 Part (a) in it shows the state of the free water in the internal defects of the rock mass in the saturated water state, Figure 9 and part (b) in it shows the state of the free water in the internal defects of the rock mass in the natural state. In the saturated water state, all the internal defects of the ore are filled with free water, and only a little free water exists in the defects in the natural state, and the rest of the space is air.

[0076] As Figure 10 shown, when two plates are separated in the vertical direction at a relative speed, the liquid will exert a reverse resistance stress on the two plates. From the expression of the resistance stress of the Stefan effect, it can be obtained that the resistance generated by the Stefan effect is proportional to the relative movement speed of the two side plates. Therefore, even if there is less free water in the ore rock with a low saturation water - content rate, under the action of a high - strain - rate load such as the blasting load, the resistance generated by it still has a certain hindering effect on the nucleation and propagation of micro - cracks, and will increase the ability of the ore to resist the blasting load.

[0077] The meniscus effect is as Figure 11 shown. Figure 11 Part (a) in it shows the schematic diagram of the crack - tip propagation under static load.Figure 11 Part (b) in it is a schematic diagram of crack tip propagation under dynamic load. In the static test, under the action of external static stress σ s , pore water pressure P2 is generated in the free body inside the ore. Since the crack propagation speed is relatively slow, the water inside the ore can reach the crack tip in time, as shown in Figure 11 part (a), which promotes crack propagation. Therefore, in the static test, as the moisture content increases, the strength of the specimen shows a decreasing trend. Under the action of dynamic load σ d , the crack propagation speed is very fast. Since the free water cannot reach the crack tip in time during the crack propagation process, the free water inside the ore cannot play a lubricating role in the crack tip, increasing the difficulty of crack propagation. At the same time, the free water in the crack will form a meniscus, as shown in Figure 11 part (b), generating a resistance stress P4 at the crack tip, hindering crack propagation.

[0078] When the ore is in the natural state, the content of free water in the pores is low, as shown in Figure 9 part (b). The free water adheres to the surface of the ore skeleton and is difficult to form the Stefan effect and meniscus effect. At this time, the physicochemical effect is the dominant one, the strength of the ore decreases, and at the same time, the free water reduces the initiation difficulty of the initial crack. Therefore, the damage is the greatest at this moment; when the ore is in the saturated water state, the free water in the ore reaches saturation, as shown in Figure 9 part (a). Although the strength of the ore is further reduced, at this time, the Stefan effect and meniscus effect are the dominant ones, and the propagation of explosion cracks is hindered, and the damage is reduced instead. Especially in the third stage of crack propagation, the acting force of stress wave and explosion-generated gas decreases. At this time, crack propagation is mainly affected by inertial force, while the resistance generated by the Stefan effect and meniscus effect remains unchanged, increasing the difficulty of crack propagation, which significantly reduces the damage degree of the ore.

[0079] Figure 12 Part (a) shows the state of internal defects of the ore when it is in the dry state. There is no free water inside the defects, and there is a certain interval between the upper and lower plates, which is filled with air. Figure 12 Part (b) shows the state of internal defects of the ore when it is in the natural state. There is only a little free water, and the rest of the space is air.

[0080] The strength of the specimen in the dry state is not affected by free water, and the crack initiation is not affected by the lubrication effect of water. Therefore, it is not affected by physical and chemical effects. At the same time, the Stefan effect and the meniscus effect do not occur. At this time, the crack propagation is only affected by the properties of the ore itself. In the natural state, the Stefan effect and the meniscus effect also do not occur, but the strength of the ore is reduced to a certain extent by the influence of water. At the same time, the crack initiation is affected by the lubrication of water, and the initiation difficulty is reduced. Therefore, its damage is higher than that in the dry state.

[0081] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0082] In this article, specific examples are used to elaborate on the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for determining the blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of water content, characterized in that, The blasting hole pattern parameters include the hole spacing of the main blasting holes, the row spacing of the main blasting holes, and the charge amount of the blast holes; the method for determining the blasting hole pattern parameters of water-saturated ore rock in a metal mine considering the influence of moisture content includes: Determining the damage reduction coefficient based on the moisture content of the ore rock in the main blasting area; Calculating the hole spacing of the main blasting holes and the row spacing of the main blasting holes based on the damage reduction coefficient; If all the ore rock in the main blasting area is in a water-saturated state, or part of the ore rock is in a water-saturated state and the other part is in a normal state, then calculate the charge amount of each blast hole in the main blasting area based on the damage reduction coefficient.

2. The method for determining the blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of water content according to claim 1, wherein, The method for determining the blasting hole pattern parameters of water-saturated ore rock in a metal mine considering the influence of moisture content further includes: If all the ore rock in the main blasting area is in a normal state, then calculate the charge amount of each blast hole in the main blasting area according to the hole spacing of the main blasting holes and the row spacing of the main blasting holes.

3. The method for determining the blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of water content according to claim 1, characterized in that Determining the damage reduction coefficient based on the moisture content of the ore rock in the main blasting area specifically includes: Calculating the rock water saturation coefficient based on the moisture content of the ore rock in the main blasting area and the saturated moisture content; Determining the damage reduction coefficient based on the rock water saturation coefficient.

4. The method for determining the blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of water content according to claim 1, characterized in that, Calculating the hole spacing of the main blasting holes and the row spacing of the main blasting holes based on the damage reduction coefficient specifically includes: Calculating the hole spacing of the main blasting holes according to the damage reduction coefficient, the bottom resistance line of the blast holes in the main blasting area, and the hole density coefficient; Calculating the row spacing of the main blasting holes according to the damage reduction coefficient, the hole spacing of the main blasting holes, and the burden area of the blast holes.

5. The method for determining the blast hole pattern parameters of saturated ore and rock in a metal mine considering the influence of water content according to claim 1, characterized in that, Calculating the charge amount of each blast hole in the main blasting area based on the damage reduction coefficient specifically includes: If all the ore rock in the area where the explosive is located is in a water-saturated state, then calculate the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the damage reduction coefficient, the hole spacing of the main blasting holes, the bench height, the bottom resistance line of the blast holes in the main blasting area, and the unit explosive consumption; calculate the charge amount of each blast hole except the first row of blast holes in multi-row blasting according to the damage reduction coefficient, the hole spacing of the main blasting holes, the row spacing of the main blasting holes, the unit explosive consumption, the bench height, and the ore rock resistance increase coefficient; If part of the ore rock in the area where the explosive is located is in a water-saturated state and the other part is in a normal state, then calculate the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the water depth in the blast hole, the explosive depth in the blast hole, the damage reduction coefficient, the hole spacing of the main blasting holes, the bench height, the bottom resistance line of the blast holes in the main blasting area, and the unit explosive consumption; calculate the charge amount of each blast hole except the first row of blast holes in multi-row blasting according to the water depth in the blast hole, the explosive depth in the blast hole, the damage reduction coefficient, the hole spacing of the main blasting holes, the row spacing of the main blasting holes, the unit explosive consumption, the bench height, and the ore rock resistance increase coefficient.

6. The method for determining the blast hole pattern parameters of saturated ore and rock in metal mines considering the influence of water content according to claim 2, characterized in that, Calculating the charge amount of each blast hole in the main blasting area according to the hole spacing of the main blasting holes and the row spacing of the main blasting holes specifically includes: Calculating the charge amount of each blast hole in single-row blasting or the charge amount of each blast hole in the first row of multi-row blasting according to the hole spacing of the main blasting holes, the bench height, the bottom resistance line of the blast holes in the main blasting area, and the unit explosive consumption; Calculating the charge amount of each blast hole except the first row of blast holes in multi-row blasting according to the hole spacing of the main blasting holes, the row spacing of the main blasting holes, the unit explosive consumption, the bench height, and the ore rock resistance increase coefficient.

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