Three-dimensional digital optimization design of underground mine mining system

At present, the domestic mine design generally adopts the AutoCAD two-dimensional design method. This method has many problems such as many drawings, large workload, large error, low efficiency, etc. It is difficult to visually express the complex three-dimensional geological features of the mine and the distribution characteristics of the tunnel engineering. The spatial structure relationship of the mine depends entirely on the designer's subjective imagination. If the design scheme is wrong, it is very likely
Caused huge economic losses [1]. With the continuous development of computer technology, the mining engineering softwares such as Surpac, Datamine, Micromine, 3DMine and DiMine have been matured, and have been widely used in mine 3D visualization and mine design [2-9], which has laid a foundation for mine 3D digital design. Solid foundation. The three-dimensional digital design of the mine can clearly display the earth's surface, structure, ore body occurrence characteristics, development of transportation system, roadway engineering, ventilation system, mining process and other information, and assist in the optimization of mining design options. Improve mine design efficiency and accuracy. In this study, three-dimensional optimal design of a large silver-gold mine complex in Guangdong as an example of the mining system.
1 Mine 3D digital design method and process
The foundation of the three-dimensional digital design of the mine is to create a mine foundation model based on the established mine database (mainly including surface model, ore body model, structural model and block model). At present, there are two main types of modeling methods: 1 various models required to make virtual scenes through mature 3D modeling software (Surpac, 3DMine, 3DMax, etc.); 2 modeling by 3D scanners (eg gob model) The modeling methods commonly used are Delaunay triangle connection method, hatching method, midline + roadway section method and roadway measurement method [10]. The main content of the three-dimensional digital design of the mine is to establish a model of the development of transportation system, shaft engineering, ventilation engineering, mining method, goaf, equipment, etc. based on the basic model. Based on this, the rapid statistics of 3D modeling software are used. The function carries out comparative analysis of the corresponding technical and economic indicators and selects the optimal design. The three-dimensional digital design process of the mine is shown in Figure 1.

2 case analysis
2.1 Project Overview
A large-scale complex silver-gold mine in Guangdong is a new mine consisting of adjacent Changkeng Gold and Silver Mine and Fuwan Silver Mine. The designed mining method is underground mining with a production capacity of 6000t/d (1980kt/a). The mining area is adjacent to the Xijiang River. According to the regulations of the “Dagan River in the 500m River” in Guangdong Province, the ore body within 500m west of the Xijiang River is prohibited from mining. The ore body is located in the structural fracture zone (aquifer), which is a gently inclined-sloping, thin-medium-thick ore body. The ore body has a longer strike, a larger morphological change, and a higher ore grade. The mining method is recommended for the mechanized road filling method of the panel, and the rock drilling and scraping machine is used for drilling. The inclination angle of the silver ore body is 10°～30°, and the shape of the ore body changes greatly. Therefore, the height of the middle part of the silver ore body is 30m, and the ore body is divided into -20, -50, -80, -110, -140, -170,- 200, -230, -260m middle section.
The gold ore body is a sloping-sloping ore body, and the change of the ore body shape is relatively small. The design considers the two middle sections to be a middle section mining. The ore bodies within the design range are divided into 10, -50, -110, -170. -230m middle section. Mines have high environmental and safety requirements and mining technology is difficult.
2.2 Basic model creation
(1) Surface model. A series of contours with elevations and elevations (topographic contours) with elevations are automatically connected to the triangulation via Surpac software to generate the surface model.
(2) Ore body model. The ore body model is generated by the hatching method. Firstly, according to the profile of each exploration line of the existing two-dimensional ore body of the mine, the Surpac software converts the coordinates into a series of three-dimensional profiles; then the adjacent exploration lines connect the triangulation according to the trend of the ore body, in the ore body Segment, closed, forming an ore body solid model (Figure 2).

2.3 Develop 3D digital optimization design of transportation system
The tunnel engineering model is mainly generated by Surpac software using the hatching method and the midline + lane section method. Due to the large change of the ore body (especially the silver ore body), considering the flexibility of the middle section of the trackless transportation, it can be well adapted to the change of the ore body shape. The middle section of the design adopts the trackless transportation. The mine and waste rock are all transported by the 30t underground truck. . according to
The topographical features of the mining area, the occurrence characteristics of the ore body and the location of the mining industry site are considered as follows.
2.3.1 Development plan
2.3.1.1 Slope Road (2) Scheme (Scheme I)
There are 2 ramps, which are 1# and 2# ramps. The 1# and 2# slopes are all arranged in the east wing of the deposit. They are arranged in a fold-back arrangement with an opening elevation of +20m. During the infrastructure construction, they are drilled to the middle section of -110m, which are connected to the middle sections. The slope is considered at 12%. In addition, two ramps are provided with a wrong lane or avoiding diverticulum every 300 to 400 m. The 1# ramp is used for the decentralization of personnel, materials and equipment and downhole trucks. It also serves as an intake shaft. It is required to set up a sidewalk. It adopts a straight wall three-core arch section. The straight section has a net width of 5.0m and a straight wall height of 2.5m. 2# Slope road is used for the transportation passage of mine and waste rock. It also serves as the inlet shaft. It does not consider setting the sidewalk. It adopts the straight wall three-core arch section. The straight section has a net width of 4.5m and the straight wall height is 2.6m. The middle section of the ore is loaded into the downhole truck through the vibrating and concentrating machine in the lower part of the stope, and then transported by the 30t underground truck to the surface ore yard or the selected factory silo through the middle section of the roadway, ramp and surface road. The middle section of the waste rock is transported to the waste rock yard by a 30t underground truck through the middle section of the roadway, ramp and surface road.
The physical model of the development transport project of Scheme I is shown in Figure 3.

2.3.1.2 Slope Road + Tape Inclined Well Scheme (Scheme II)
The position, section, function, connected middle section and slope of the slope are the same as those of the 1# slope of Scheme I, but it is required to dig to the -260m elevation during the infrastructure construction. The inclined shaft of the tape is a bright inclined shaft, which is responsible for the lifting task of gold, silver ore and waste rock, and the mine and waste rock are upgraded in different periods. The inclination angle of the slope is 14°, the elevation of the wellhead is 50m, the elevation of the well bottom is -245m, the bandwidth is 1.2m, the belt speed is 3.15m/s. The inspection channel is built in. The straight wall three-heart arch section is adopted, and the straight section is 4.5m wide. The height is 1.9m, and there is a centralized loading point at the bottom. The height of the mining belt is -240m. The mines and waste rock in each middle section are first unloaded from the 30t underground truck to the mine and waste rock. The material is then discharged into the inclined well belt through the collecting belt under the slip shaft. The inclined shaft belt transports the mine and waste rock out of the surface at different intervals. The waste rock after being transported out of the surface is transported to the waste rock yard through a surface waste stone belt. The ore is transported to the plant through a surface ore belt, and a surface reversible belt is connected under the ore belt to discharge the gold and silver mines respectively. Mine bin. The mid-section transportation plan is consistent with option I. The physical model of the development transport project of Scheme II is shown in Figure 4.

2.3.1.3 Slope Road + Bucket Shaft Scheme (Scheme III)
The relevant parameters and functions of the ramp are consistent with the ramps of Scheme II. The bucket shaft is an open shaft and is responsible for the lifting of gold, silver ore and waste rock. The height of the wellhead is +50m, the lowest in the middle of the mine is -230m, the concentration of the centralized transfer is -260m, the level of the bucket is -290m, the bottom of the well is -340m, the diameter of the wellbore is 6.0m, and the ladder is set inside. There is a set of double buckets (silver mine) and a set of single buckets with balance hammer lifting system (gold mine and waste rock) in the wellbore, all of which are wire rope cans. Among them, the double bucket lifting system uses two 5m3 bottom dump buckets and JKM2.8×4 multi-rope friction hoist. The single bucket with balance hammer lifting system adopts 5m3 bottom dump bucket and more than 17.5t. The rope balance hammer adopts JKM2.8×4 multi-rope friction hoist. The concentration level is set at -260m level, the glue width is 1.2m, the belt speed is 1.6m/s, and the length is 1100m. One of the inclined wells was recovered from the bottom of the well, and the horizontal well was drilled from -370m to a level of -290m with an inclination of 30°. The middle section of the mine and waste rock are first transported by the 30t underground truck through the middle section of the roadway to the mine and waste rock shaft for unloading; then they are transported by the vibrating ore concentrator and then transported to the vicinity of the bucket well through the -260m middle transfer belt and unloaded into the bucket. The ore belt, the bucket loading belt will load the mine and waste rock into the bucket and finally propose the surface; finally, it will be transferred to the selected mine bin and waste quarry by the car. The mid-section transportation plan is consistent with option I. The physical model of the development transport project of Scheme III is shown in Figure 5.

2.3.2 Development system plan optimization
The technical and economic comparison analysis of the schemes I, II and III was carried out from the comparable well engineering quantity (using the Surpac software statistics), the comparable total investment, the operating cost, and the present value of the cost. The results are shown in Table 1.

It can be seen from Table 1 that Scheme I is superior to the other two schemes in terms of comparable infrastructure construction, comparable total investment, comparable capital investment, and present value of cost. At the same time, the mine and waste rock of Scheme I do not need to be transported, and the system is simple and flexible. The management is relatively convenient, so the recommended scheme I, that is, the ramp (2) scheme is the optimal scheme.
2.4 ventilation system three-dimensional digital design
According to the occurrence conditions of the ore body and combined with the recommended development transportation system, the ventilation system of the large-scale silver-gold mine is designed to adopt the flank diagonal extraction type.
Considering that the mine production scale is large, the two slopes cannot meet the air intake requirements, so it is necessary to newly dig the special (return) wind shaft. A south inlet wind shaft (4.0m) was newly built in the south wing of the mining area, and a north inlet wind inclined shaft was newly drilled in the north wing of the mining area (using a three-core arch section, the straight section has a net width of 4.5m and a straight wall height of 1.9m). An east return wind shaft (6.5m) was newly drilled in the east wing of the mining area. The solid model of the large silver-gold mine ventilation system is shown in Figure 6. The design fresh air flow first enters from the north inlet wind inclined shaft, the south inlet wind shaft and two slope roads; then it enters the working surface by the inlet wind door, the (wearing) vein roadway, the mining area slope road, the section roadway, etc. After the surface, the dirty wind passes through the ventilated patio, the upper middle section wears (along) the vein roadway, and returns to the stone gate, and finally the east return air shaft draws the surface.

3 Conclusion
Taking a large-scale silver-gold mine in Guangdong as an example, the three-dimensional digital design method of the mine was used to establish the three-dimensional geological model of the mine. Based on this, the three-dimensional design of the mining system was carried out and the development of the transportation scheme was optimized. The three-dimensional digital design level of the mining system has certain reference value.
references
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Author: Guo Mingming; Changsha Nonferrous Metallurgy Design and Research Institute Co., Ltd;
Li Jiehui ; Hunan Institute of Nonferrous Metals;
Article source: "Modern Mining"; 2016.8;
Copyright:

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