In order to ensure the safety of the construction process and reduce the loss rate of ore, especially to reduce the ore loss in the upper part of the peach-shaped pillar, this paper proposes a layered and reinforced concrete artificial false bottom design. The bottom structure is 7m high and the size of the mine exit is 3m×3m. Considering that the scraper is shoveled, the fuselage can be shoveled when it is in a straight line, which not only reduces the damage of the scraper, but also improves the shovel. Mine efficiency. The shovel is carried out in the funnel approach, so the length of the funnel approach is analyzed. The scraper enters the funnel approach to shovel. The longer the fuselage, the longer the length of the required funnel approach and the greater the loss of ore. Therefore, in order to reduce the amount of ore loss, it is determined to use the ST2D type scraper. According to the parameters of the ST2D type scraper, the funnel approach length is designed. When the funnel approach length is 6m and 7m, the operation of the scraper is shown in Figure 1. In order to ensure that the scraper smoothly enters the funnel approach and reverses into the scraper once, consider that the funnel approach is 6m and 7m long, and the centerline turning radius is 4.5m, and the centerline 4.5m turning radius line The distance between the inner 3m turning radius line is 1.5m, and the maximum width of the scraper is 1.638m, which is much larger than half the width of the scraper. Therefore, the scraper can be transferred to the funnel approach. It can be seen from Fig. 1 that in the case of 6m and 7m, when the scraper is turned into parallel with the approach, the tail distance of the tail is 9.8m and 11m respectively, judging from the farthest position of the ore outflow, in the case of 6m The head of the scraper just reached the edge of the pile, and there is still a distance in the case of 7m. Considering that the length of the funnel approach is longer, the ore loss is larger and the distance is larger. Therefore, the 6m long funnel can be used. Meet the shoveling requirements while reducing ore loss and improving shovel efficiency. After the end of each approach, the corresponding mining structure (gutter) is reserved during filling, and the top of the trench is anchored, and the width of the top of the rocking tunnel is greater than 4.0m and the thickness is greater than 0. The 5m reinforced concrete structure is filled with C20 concrete to ensure the safe construction of rock drilling and medium-deep hole blasting. In addition, the watering body of each road is connected by steel bars to ensure that the poured reinforced concrete forms a whole. The layered construction is carried out in 3 steps: The first step is to dig the first section of the shovel and section. Enter the stratification from the roadway (A, A1, A2) at the northern end of the main slope of the west, and dig a 27m long section (3.5m × 3.5m) in the east-west direction at the A2 position, and then at the position of the shovel From the north to the south, the first section of the shovel (3m × 3m) is drilled and the length is 50m. After the shovel is completed, the section of the road (3.5m × 3.5m) is drilled to the east and west sides, and the length is 27m. 2 is shown. Support two gangs during the excavation process to prevent accidents. The second step is to construct the second section, from the middle section of the roadway to the south of the construction approach (3m × 3.5m), when the road is filled, first build a layer of reinforced concrete greater than 0.5m thick at the bottom, and then Fill the way. The designed rock drilling and mining roads are not filled, and the filling bodies on both sides of the rock drilling and mining roads are made of high-grade concrete to ensure the safety of mining, as shown in Figure 3. There are 9 ways in the section, and 2 working faces are constructed at the same time. In order to make the adjacent roads not be constructed at the same time, and the new construction approach is not adjacent to the newly completed approach, the approach shown in Figure 4 is adopted. The order of construction replacement. After the construction of the second section is completed, it will be recovered from the south to the north. The third step is to carry out the sealing treatment after the second section is mined, the middle section is reserved, and then the first section is constructed, and the first section is arranged as shown in FIG. 5. In this section, 8 roads are excavated. In order to reduce the amount of unnecessary tunneling and watering in the rock, the three roads on the east side are constructed from the middle section of the road from south to north. The road is constructed from north to south from the north side section. The principle of construction sequence is also that the adjacent approaches are not constructed at the same time, and the new construction approach is not adjacent to the newly completed approach. The construction sequence of this section is shown in Figure 6. Through the use of reinforced concrete artificial false bottom, each layered construction approach is cross-arranged, and the watering bodies support each Other, which improves the stability of the bottom structure; the shovel approach and the shovel path are protected by reinforced concrete, which is safely guaranteed. The operating environment has also been improved; making full use of mineral resources, increasing the recovery rate, extending the service life of the mine, and lowering the cost to make it have obvious economic and social benefits. At the same time, the blasting and ore-mining has an impact on the bottom structure, the demineralization process causes damage to the bottom structure, and how to detect the bottom structure, etc., it is also necessary to improve and improve it. In short, the use of artificial false bottoms for mining high-grade ore bodies is of great significance, and the importance of increasing the recovery rate of ore resources has gradually emerged under the current shortage of mineral resources. This technology has broad application prospects. . Packaging Printing,Custom Printed Boxes,Printed Packaging Bags,Customized Packaging Boxes Hangzhou Aoxin Culture Technology Co., Ltd. , https://www.aoxinks.com
1 Geological Overview The ore body within the designed mining area is mainly sulfide ore. The ore body is north-south trending and tends to the west. The designed ore section has a length of 100m and an elevation of 1540~1600m. The shape of the ore body varies greatly along the strike. Sulfide ore bodies are generally stable, with an average density of 3.6 to 3.8 t/m3, a looseness coefficient of 1.53, a natural angle of repose of 36°50' to 41°25', and a friction angle of 40°33'. The block size is generally greater than 10 cm. The surrounding rock of the sulphide ore body is marble or gray dolomite , which is relatively intact and stable, and generally is not easy to collapse; the bottom plate is skarn and granite , which is hard rock, the granite is easy to weather, and it is not stable after weathering. On the west side of the mine section, a north-south-high west main slope (4m×4m) has been excavated, which is located in the upper rock mass of the ore body, and the elevation is just close to the bottom of the ore body. In the north and south sides of the mine section, there are tunnels for the service of the mine section.
2 funnel approach size determination
For the comparison of ST2D and ST7 scrapers, the parameters of the scraper are shown in Table 1 [4]. 
3 concrete false bottom design The bottom structure is divided into 3 layers, which are constructed from top to bottom.
3.1 First stratified construction This stratification is mainly for the replacement of the ore lost from the tip of the peach-shaped ore column, and there is only one approach along the strike (3m × 3m). In the process of mining, the ore below 2m on both sides of the approach road can be retracted, and the concrete is filled after the end of the mining. Support the roof during the tunneling process to prevent roofing accidents.
3.2 Second layer construction This layering is mainly to form the upper part of the trench. The direction of the roadway (4m×4m) is perpendicular to the direction of the road. The layered floor is the same as the floor of the west main ramp. Directly digging into the east from the main slope of the west, a total of 24, the maximum length of the road is 47.5m.
Two working faces are used for construction at the same time. In order to make the adjacent access roads not constructed at the same time, and the new construction approach is not adjacent to the newly completed approach, the jump mining is adopted. Due to the large volume of watering and the hydration heat phenomenon of concrete, cracking is prone to occur. Therefore, layered watering is adopted, the layering height is 0.5m, the cement number is C20～C25, and the joint of the funnel and the neck is cemented. For C30. Reinforcement is made of 18~20mm rebar, single-layer arrangement, with a spacing of 160mm. The position where the part is easily damaged is double-layered ribs and 18mm rebar with a spacing of 160-180mm.
3.3 The third layer of the third layer is mainly to form the lower part of the trench. The approach is arranged along the ore body. The section of the road is 3m×3.5m. When the road is filled, first build a bottom. The layer is thicker than 0.5m thick reinforced concrete (to ensure the recovery of the lower ore), and then the filling is fully filled. The designed rock drilling and mining roads are not filled, and the filling bodies on both sides of the rock drilling and mining roads are made of high-grade concrete to ensure the safety of mining.
4 Conclusion
References [1] He Hongxuan, Fan Yongkui. The application of steel structure artificial false bottom in the Yu'erya gold mine [J]. Gold, 2008, 29(1): 33-36.
[2] Luo Shaowen, Li Yulin. Destructive form of concrete false bottom and method of reinforcement [J]. Mining Research and Development, 1996, 16(2): 19-21.
[3] Gong Xinhua, Hou Kepeng, Sun Jian. Application status and prospect of artificial false bottom in metal mines [J]. China Tungsten Industry, 2014, 29 (1): 21-24.
[4] Wang Yunmin. China Mining Equipment Handbook [M]. Beijing: Science Press, 2007
Article source: "Modern Mining", 2017.4
Author: Sun made the hospital, Cheng Chung; Yunnan Sub financial Mines Ltd. Houke Peng, Sun Huafen; Faculty of Land Resource Engineering, Kunming University of Science Copyright:
Artificial false bottom design of a sulphide ore reinforced concrete
The earliest in the early 1980s, by the Changchun Gold Research Institute in the implementation of reinforced concrete Honghuagou gold false bottom [1], to improve the recovery of resources. Some mines have also used artificial false bottoms to replace the ore bottom column in high-grade ore belts in order to recover the bottom column minerals as much as possible [2]. At present, the main form of artificial false bottom in metal mines is the reinforced concrete false bottom, in addition to the false bottom of different materials and forms such as steel structure false bottom, paste filling false bottom, pit wood false bottom, steel net flexible isolation false bottom; The application range of the false bottom is also developed from the initial extremely thin and thin veins to medium and thick ore bodies; the applicable mining methods have also evolved from the initial retention method to the filling method and the bottomed column collapse method [3].