Mining methods for extremely thin mineral veins

Abstract

The present invention provides a method for mining extremely thin ore veins, and relates to the technical field of underground mining of metal ore deposits. The method for mining extremely thin ore veins provided by the present invention includes: preliminarily determining the ore body information through drilling exploration, and forming a prospecting borehole; setting the rear end of the mining pipeline on the ground, and lowering the front end of the mining pipeline into the ore body through the prospecting borehole; the front end of the mining pipeline is provided with a directional drill bit, and the rear end is connected to a pumping mechanism; then the directional drill bit is used to drill and grind the ore body, and the formed slurry is transported out through the pumping mechanism; during the drilling and grinding mining process, the ore body is accurately positioned using the drilling data and the mining direction of the directional drill bit is adjusted in real time; after the mining is completed, the filling material is transported to the goaf through the prospecting borehole for filling. In the above manner, the present invention does not need to set up complex underground development and mining engineering, and realizes the efficient mining of extremely thin ore veins with broken ore rocks and small ore vein thickness while reducing the mining cost.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining of metal ore deposits, and in particular to a mining method for extremely thin ore veins. Background Art

[0002] At present, traditional mining methods for extremely thin veins mainly include wall-cutting and filling mining, ore-retaining mining, room-and-pillar mining, and comprehensive mining. However, these mining methods have problems such as high mining costs, poor depletion loss indicators, high labor intensity, low mining efficiency, and large environmental damage during the mining process. In addition, when the ore rock is broken or the ore vein thickness is small, traditional mining methods often face the problems of high mining costs and unsafe mining environment. Due to the constraints of economic and technical factors, they cannot be mined normally, making it impossible for the corresponding mineral resources to be effectively utilized. How to efficiently mine extremely thin ore veins with broken ore rocks and small ore vein thickness that cannot be effectively mined by traditional methods is still a problem that needs to be solved urgently.

[0003] In the prior art, the patent with publication number CN115749796A provides a mechanized ore-rock separation method suitable for gently inclined and extremely thin ore veins, including: central pedestrian ventilation uphill excavation, deep hole pre-splitting blasting of the two sides of the surrounding rock, dry filling of the goaf with collapsed surrounding rock, and non-explosive continuous separation of extremely thin ore veins on the roof. This patent solves the outstanding problems of low production capacity, large waste rock output, difficult to control ore depletion, high lifting, transportation and beneficiation costs of the gently inclined and extremely thin ore veins by adopting the ore-rock separation process to replace the ore-rock mixed mining process. The patent with publication number CN109026003A provides a continuous mining method of spiral drill mining machine for soft rock ore bodies of gently inclined and extremely thin ore veins. This patent adopts a spiral drill mining machine for reciprocating mining, while carrying out backfilling uphill and roof support, and forced ventilation of the working face. It has the characteristics of high safety, strong continuity, low depletion rate, economic efficiency, simple process and low labor intensity.

[0004] However, the projects of the above-mentioned patents are mainly concentrated underground, and require a large number of development and mining projects to be arranged in the underground rock mass. Not only is the project volume large and the construction cost high, but it is also only applicable to gently inclined and extremely thin veins. It is difficult to construct and support extremely thin veins with broken ore rocks or small thickness. In actual mining, there are also problems of excessive investment costs and lack of economic feasibility.

[0005] In view of this, it is necessary to design an improved mining method for extremely thin ore veins to solve the above problems. Summary of the invention

[0006] In view of the defects of the above-mentioned prior art, the purpose of the present invention is to provide a mining method for extremely thin mineral veins. By omitting the underground mining preparation project and entering the underground only through a drill bit and a mining pipeline, it is possible to effectively reduce the mining cost while realizing in-situ efficient mining of extremely thin mineral veins with broken ore rocks and small mineral vein thickness.

[0007] To achieve the above object, the present invention provides a method for mining extremely thin mineral veins, comprising the following steps:

[0008] S1. Conduct drilling exploration in the area to be mined, preliminarily determine the ore body information, and form several prospecting boreholes connected to the ore body;

[0009] S2. The rear end of the mining pipeline is set on the ground, and the front end of the mining pipeline is lowered into the ore body through the prospecting borehole; the front end of the mining pipeline is provided with a directional drill bit, and the rear end of the mining pipeline is connected to the pumping mechanism;

[0010] S3. The ore body is drilled and mined by the directional drill bit, and the formed slurry is transported out by the pumping mechanism; during the drilling and mining process, the ore body is accurately located by using the drilling data and the mining direction of the directional drill bit is adjusted in real time;

[0011] S4. After the mining is completed, the filling material is transported to the goaf through the prospecting borehole for filling.

[0012] As a further improvement of the present invention, in step S3, the step of using the drilling data to accurately locate the ore body and adjust the mining direction of the directional drill bit in real time includes:

[0013] Real-time collection of drilling data during the drilling and grinding process;

[0014] Determine whether the current location of directional drilling belongs to the ore body based on the real-time collected drilling data;

[0015] If the location where the directional drill is mining belongs to the ore body, the mining direction of the directional drill remains unchanged; if the location where the directional drill is mining does not belong to the ore body, the mining direction of the directional drill is adjusted until the location where the directional drill is mining belongs to the ore body.

[0016] As a further improvement of the present invention, the step of determining whether the current directional drill mining position belongs to the ore body comprises:

[0017] Determine the fitting relationship between various while-drilling data corresponding to the ore body to be mined;

[0018] One of the various while-drilling data collected during the drilling and grinding mining process is used as the dependent variable, and the other while-drilling data collected are substituted into the fitting equation as independent variables to calculate the fitting value of the dependent variable; then the actual measured value of the dependent variable is compared with the fitting value, and if the error is within the threshold range, it is determined to belong to the ore body; if the error exceeds the threshold range, it is determined not to belong to the ore body.

[0019] As a further improvement of the present invention, the fitting relationship between various while-drilling data corresponding to the ore body to be mined is obtained by fitting the while-drilling data collected during the drilling exploration in step S1.

[0020] As a further improvement of the present invention, the drilling data includes the rotation speed, drilling rate and drilling pressure of the directional drill bit.

[0021] As a further improvement of the present invention, the outer diameter D1 of the mining pipeline, the diameter D2 of the directional drill bit and the average thickness L of the ore body satisfy the following relationship:

[0022] 0.9D2≤D1≤D2, 0.9L≤D2≤1.1L.

[0023] As a further improvement of the present invention, in step S1, the ore body information includes the ore body location and ore body occurrence.

[0024] As a further improvement of the present invention, in step S2, the pumping mechanism is a screw conveyor or a mortar pump.

[0025] As a further improvement of the present invention, in step S3, the following steps are also included:

[0026] The ore pulp transported by the pumping mechanism is transported to a beneficiation plant for beneficiation to obtain concentrate and tailings.

[0027] As a further improvement of the present invention, in step S4, the filling material is formed by mixing the tailings and cement slurry.

[0028] The beneficial effects of the present invention are:

[0029] The mining method of the extremely thin ore vein provided by the present invention preliminarily determines the ore body information through drilling exploration, and then uses the prospecting borehole formed in the drilling exploration process to lower the mining pipeline with a directional drill bit at the front end into the ore body, and uses the collected drilling data to accurately locate the ore body and adjust the mining direction of the directional drill bit in real time during the drilling and grinding mining process, thereby realizing the in-situ and efficient mining of the extremely thin ore vein. Based on the mining method of the extremely thin ore vein provided by the present invention, there is no need to set up complex underground development and mining projects, and only the prospecting borehole can be used for mining, which has the advantages of small infrastructure investment, fast production speed, low mining cost, and good depletion index. In addition, the method provided by the present invention has little disturbance to the underground original rock, and personnel do not need to work underground. No tailings or waste are generated in the whole process. It can be applied to the mining of extremely thin ore veins with broken ore rocks and small ore vein thickness, and achieves green, safe and environmentally friendly mining effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the stope structure when mining extremely thin ore veins in the embodiment.

[0031] Reference numerals

[0032] 1. Mining pipeline; 2. Directional drill bit; 3. Pipeline derrick; 4. Slurry conveying pipeline; 5. Ore dressing plant; 6. Tailings conveying pipeline; 7. Filling station; 8. Surrounding rock; 9. Ore body. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0035] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0036] The present invention provides a method for mining an extremely thin mineral vein, comprising the following steps:

[0037] S1. Conduct drilling exploration in the area to be mined, preliminarily determine the information of the ore body 9, and form several prospecting boreholes connected to the ore body 9;

[0038] S2. The rear end of the mining pipeline 1 is set on the ground, and the front end of the mining pipeline 1 is lowered into the ore body 9 through the prospecting borehole; the front end of the mining pipeline 1 is provided with a directional drill bit 2, and the rear end of the mining pipeline 1 is connected to the pumping mechanism;

[0039] S3. The ore body 9 is drilled and mined by the directional drill bit 2, and the formed slurry is transported out by the pumping mechanism; during the drilling and mining process, the ore body 9 is accurately located by using the drilling data and the mining direction of the directional drill bit 2 is adjusted in real time;

[0040] S4. After the mining is completed, the filling material is transported to the goaf through the prospecting borehole for filling.

[0041] Through the above-mentioned method, the present invention can greatly simplify the mining and verification engineering, directly use the prospecting borehole formed in the drilling exploration process, and only need to lower the mining pipeline 1 with the directional drill bit 2 at the front end of the mining into the ore body 9 to carry out drilling and grinding mining, and the mining direction of the directional drill bit 2 can be adjusted using the drilling data during the mining process, so as to achieve accurate positioning and mining of the ore body 9. Compared with the conventional underground mining method, the present invention does not need to set up complex underground development and mining and verification engineering, the infrastructure investment is smaller, the production speed is faster, the mining cost is lower, and the disturbance to the underground original rock is small. Personnel do not need to work underground, and it has higher safety, and can be applied to the mining of extremely thin veins with broken ore rocks and small ore vein thickness.

[0042] like Figure 1 As shown, in some preferred embodiments of the present invention, the underground mining area includes surrounding rock 8 and ore body 9, wherein the thickness of the ore body 9 is less than 0.8m, which is an extremely thin ore vein. The mining pipeline 1 is lowered into the ore body 9 through the prospecting borehole, and a pipeline derrick 3 for fixing and adjusting the position of the mining pipeline 1, a beneficiation plant 5 for beneficiating the slurry transported by the mining pipeline 1, and a filling station 7 for preparing the tailings output by the beneficiation plant 5 into filling materials are also provided on the ground. The overall structure is relatively simple, the engineering volume is small, and it can realize full-process waste-free mining.

[0043] More specifically, in some preferred embodiments of the present invention, the mining method of extremely thin mineral veins comprises the following steps:

[0044] S1. Delineation and drilling positioning of the ore body 9: Drilling exploration is carried out in the area to be mined, so that the prospecting borehole formed penetrates the surrounding rock 8 on the upper part of the ore body 9 and connects with the ore body 9. By checking the types of rock formations corresponding to different hole depths and combining with corresponding geological information, the ore body 9 is preliminarily delineated, and the location of the ore body 9, the occurrence of the ore body 9 and other ore body 9 information are determined.

[0045] The number of prospecting boreholes can be selected according to the actual exploration needs, and it is sufficient to complete the preliminary delineation and positioning of the ore body 9. In the process of drilling exploration, the drilling data of each drilling can also be collected to analyze the difference in the drilling data when drilling on the surrounding rock 8 and the ore body 9, respectively, to provide a judgment basis for the precise positioning of the subsequent drilling and grinding mining process.

[0046] S2. Setting up the mining pipeline 1: Setting the rear end of the mining pipeline 1 on the pipeline derrick 3. The pipeline derrick 3 can be used to fix the rear end of the mining pipeline 1 and adjust the position of the mining pipeline 1, so that the front end of the mining pipeline 1 is lowered into the ore body 9 through the prospecting borehole formed in step S1.

[0047] A directional drill bit 2 is provided at the front end of the mining pipeline 1, and a drill rod connected to the directional drill bit 2 is provided inside the mining pipeline 1. The directional drill bit 2 is connected to a drilling rig arranged on the ground through the drill rod. The mining direction and related mining parameters of the directional drill bit 2 are controlled by the drilling rig. The staff does not need to work underground, but only needs to operate the drilling rig on the ground to control the underground directional drill bit 2, which has higher safety.

[0048] A pumping mechanism is also connected to the rear end of the mining pipeline 1. During the drilling and grinding process of the directional drill bit 2, the drilling mud will enter the inner cavity of the drill rod and then be discharged through the slurry outlet on the directional drill bit 2 to cool the drill bit, clean the drill tool, and bring back the drill cuttings. On this basis, the ore debris formed by the directional drill bit 2 after drilling and grinding will be mixed with the mud to form a slurry, which can be transported out by the pumping mechanism. The pumping mechanism is preferably a screw conveyor or a mortar pump, and other types of pumping mechanisms can also be selected according to actual needs, as long as the mortar can be transported out.

[0049] Preferably, in some embodiments of the present invention, the outer diameter D1 of the mining pipe 1, the diameter D2 of the directional drill bit 2, and the average thickness L of the ore body 9 satisfy the relationship: 0.9D2≤D1≤D2, 0.9L≤D2≤1.1L. In this way, the diameter of the directional drill bit 2 can be basically consistent with the thickness of the ore body 9, so that the mining of the ore body 9 in the thickness direction can be completed at one time, and the mining direction of the directional drill bit 2 only needs to be adjusted along the direction of the ore body 9, which can achieve efficient mining of extremely thin ore veins.

[0050] S3. Drilling and grinding mining: The directional drill bit 2 is used to perform drilling and grinding mining on the ore body 9, and the formed ore slurry is transported out through the pumping mechanism.

[0051] During the drilling and grinding process, the ore body 9 is accurately positioned using the drilling data and the mining direction of the directional drill bit 2 is adjusted in real time. The specific steps are as follows:

[0052] Real-time collection of drilling data during the drilling and grinding process;

[0053] Determine whether the location currently mined by the directional drill 2 belongs to the ore body 9 according to the real-time collected while-drilling data;

[0054] If the mining position of the directional drill bit 2 belongs to the ore body 9, the mining direction of the directional drill bit 2 remains unchanged; if the mining position of the directional drill bit 2 does not belong to the ore body 9, the mining direction of the directional drill bit 2 is continuously adjusted until the mining position of the directional drill bit 2 belongs to the ore body 9.

[0055] In order to determine whether the current location mined by the directional drill head 2 belongs to the ore body 9, it is first necessary to determine the fitting relationship between the various while-drilling data corresponding to the ore body 9 to be mined. The fitting relationship can be preliminarily estimated based on the ore body 9 information preliminarily determined in step S1, based on experience or by referring to relevant materials, and more preferably, it is fitted based on the while-drilling data collected during the drilling exploration in step S1, so as to obtain real data that is more in line with the actual situation and improve the accuracy of the judgment.

[0056] Based on the downhole data collected during the drilling exploration stage, the downhole data obtained when drilling on the surrounding rock 8 can be compared with the downhole data obtained when drilling on the ore body 9, and the differences between the downhole data when drilling in different rock formations can be analyzed, and then the rules can be summarized, so that in the drilling and mining stage, it can be determined whether the rock formation belongs to the surrounding rock 8 or the ore body 9 based on the collected downhole data.

[0057] Specifically, in one embodiment of the present invention, the drilling data collected during drilling exploration and drilling and grinding mining include the rotation speed, drilling rate and drilling pressure of the directional drill bit 2. By analyzing the drilling data collected during the drilling exploration stage, it is found that the drilling rate is related to the rotation speed and drilling pressure, but when the rock formation types are different, even based on the same rotation speed and drilling pressure, the actual drilling rate will be significantly different. Based on this, the relationship between the drilling rate, rotation speed and drilling pressure corresponding to the surrounding rock 8 and the ore body 9 can be obtained respectively by data fitting. Among them, the relationship between the drilling rate, rotation speed and drilling pressure corresponding to the ore body 9 is the fitting relationship.

[0058] On this basis, the drilling rate can be used as the dependent variable, the rotation speed and the drilling pressure can be used as the independent variables, and the rotation speed and the drilling pressure collected in real time during the drilling and grinding process can be substituted into the fitting relationship to calculate the fitting value of the drilling rate. Then the fitting value of the drilling rate is compared with the actual measured value of the drilling rate. If the error is within the threshold range, it is determined to belong to the ore body 9; if the error exceeds the threshold range, it is determined not to belong to the ore body 9. Among them, the threshold range of the error can be determined according to the degree of difference between the surrounding rock 8 and the ore body 9.

[0059] Through the above-mentioned method, the type of rock layer can be accurately identified according to the changes of the drilling information, so as to adjust the mining of the directional drill bit 2 and realize the precise mining of extremely thin mineral veins.

[0060] S4. Slurry beneficiation and tailings backfilling: After the slurry formed in step S3 is transported out by a pumping mechanism, it is transported to a beneficiation plant 5 through a slurry conveying pipeline 4 for beneficiation. The useful components in the slurry are separated and enriched by grinding, magnetic separation, flotation and other processes to obtain concentrate and tailings. Then the tailings are transported to a filling station 7 through a tailings conveying pipeline 6, and the tailings are mixed with cement slurry to form a filling material. Finally, the filling material is transported to the goaf through a prospecting borehole for filling.

[0061] Through the above method, the useful components in the slurry obtained by mining can be effectively used as concentrate, and the tailings can be refilled into the goaf. The whole mining process does not produce tailings or waste, achieving a green and environmentally friendly mining effect. Among them, the specific mineral processing technology and the proportion of each component in the filling material can be selected according to the actual needs.

[0062] In summary, the mining method of extremely thin ore veins provided by the present invention can effectively utilize the prospecting boreholes formed during the drilling exploration process, lower the mining pipeline 1 with a directional drill bit 2 at the front end into the ore body 9, and then adjust the mining direction of the directional drill bit 2 in combination with the drilling data, so as to achieve accurate positioning and mining of the ore body 9. On this basis, the ore pulp obtained by mining is sent to the ore dressing plant 5 for ore dressing, and the tailings produced can be mixed with cement slurry to form a filling slurry, and then transported to the goaf through the prospecting borehole for filling, thereby realizing full-process waste-free mining. In addition, based on the method provided by the present invention, there is no need to set up complex underground development and mining projects, the disturbance to the underground original rock is small, and personnel do not need to work underground. It also has the advantages of small infrastructure investment, fast production speed, low mining cost, and good impoverishment index. It can be applied to the mining of extremely thin ore veins with broken ore rocks and small ore vein thickness, and achieve green, safe, and environmentally friendly mining effects.

[0063] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for mining extremely thin mineral veins, characterized in that: The steps include: S1. Conduct drilling exploration in the area to be mined, preliminarily determine the ore body information, and form several prospecting boreholes connected to the ore body; during the drilling exploration process, collect the drilling data of each drilling; S2. The rear end of the mining pipeline is set on the ground, and the front end of the mining pipeline is lowered into the ore body through the prospecting borehole; the front end of the mining pipeline is provided with a directional drill bit, and the rear end of the mining pipeline is connected to the pumping mechanism; S3. The ore body is drilled and mined by the directional drill bit, and the formed slurry is transported out by the pumping mechanism; during the drilling and mining process, the ore body is accurately located by using the drilling data and the mining direction of the directional drill bit is adjusted in real time, and the specific steps include: Real-time collection of drilling data during the drilling and grinding process; Determine whether the current location of directional drilling belongs to the ore body based on the real-time collected drilling data; If the location mined by the directional drill belongs to the ore body, the mining direction of the directional drill remains unchanged; if the location mined by the directional drill does not belong to the ore body, the mining direction of the directional drill is adjusted until the location mined by the directional drill belongs to the ore body; The step of determining whether the current directional drill mining position belongs to the ore body includes: According to the while-drilling data collected during the drilling exploration in step S1, a fitting relationship between various while-drilling data corresponding to the ore body to be mined is obtained; the while-drilling data includes the rotation speed, drilling rate and drilling pressure of the directional drill bit, and the relationship between the drilling rate, rotation speed and drilling pressure corresponding to the ore body is the fitting relationship; The drilling rate in the drilling data collected during the drilling and grinding process is used as the dependent variable, and the collected rotation speed and drilling pressure are substituted into the fitting relationship as independent variables to calculate the fitting value of the drilling rate; then the actual measured value of the drilling rate is compared with the fitting value, and if the error is within the threshold range, it is determined to belong to the ore body; if the error exceeds the threshold range, it is determined not to belong to the ore body; the threshold range of the error is determined according to the degree of difference between the surrounding rock and the ore body; S4. After the mining is completed, the filling material is transported to the goaf through the prospecting borehole for filling.

2. The method for mining extremely thin mineral veins according to claim 1, characterized in that: The outer diameter D1 of the mining pipeline, the diameter D2 of the directional drill bit and the average thickness L of the ore body satisfy the following relationship: 0.9D2≤D1≤D2, 0.9L≤D2≤1.1L.

3. The method for mining extremely thin mineral veins according to claim 1, characterized in that: In step S1, the ore body information includes the occurrence of the ore body.

4. The method for mining extremely thin mineral veins according to claim 1, characterized in that: In step S2, the pumping mechanism is a screw conveyor or a mortar pump.

5. The method for mining extremely thin mineral veins according to claim 1, characterized in that: In step S3, the following steps are also included: The ore pulp transported by the pumping mechanism is transported to a beneficiation plant for beneficiation to obtain concentrate and tailings.

6. The method for mining extremely thin mineral veins according to claim 5, characterized in that: In step S4, the filling material is formed by mixing the tailings and cement slurry.

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