The segmented empty field post-filling mining method is mainly applicable to the underground mining of inclined-sloping, thick and relatively continuous and stable ore bodies. It has the advantages of large production capacity, safety and reliability, and has been promoted and applied in many mines at home and abroad [1-4] ]. The design and selection of the Shangxikeng molybdenum mine is 300,000 t/a, and the flat mining method is adopted. In order to reduce the cost of mining operations and improve production efficiency, according to the technical conditions of mining and the occurrence of ore bodies, the mine adopts an empty field (the combination of the segmented empty field method and the bottomless shallow hole retention method) and the post-filling mining method. Picking up.
1 Mine Overview
The Shangxikeng molybdenum mine is developed for Pingshuo. A total of 5 layers of flat rafts are set up, which are 850, 800, 750, 700, 650m flat rafts. The main flat raft is set at 650m level, and the flat sluice is near 18 lines. There are 3 ore slides in the main level, which are connected with the other 4 layers. The ore chutes are arranged near the 10th, 2nd, and 5th lines. All the ore in the well is transported to the surface by 650m horizontally. The main flat is the entry passage of personnel, materials and equipment, and also serves as the inlet of the mine. In addition, there is a sub-level raft to the surface near the 2nd and 5th lines, which is responsible for the waste rock transportation in the middle of 650m, and also serves as the inlet well. There are two flat exits in each of the 700, 750, 800, and 850m sections. Each flat is connected to the main chute. A main ventilation patio is installed near the 7th line, and diagonal ventilation is formed with each flat mouth. Withdrawn ventilation.
2 mining conditions
The rock mass in the ore section is composed of hard black cloud sloping granulite and a few metamorphic rocks such as gneiss granite . The rock structure types are mainly layered, strip or block. Affected by weathering and structure, the rock in the ore section has a gradual transition from top to bottom from fragmentation to integrity and from weak to hard. The shallow IV and V structural planes in the ore section are particularly developed, the II and III grades are less, the ore body and surrounding rock are well stabilized, and the mining conditions are better.
During the construction of the tunnel, only a small part of the roof has collapsed and dropped, which mainly occurs in the structurally fractured and fissure-developed dense belts, and the collapse caused by the weaker interlayer has not been seen.
Slate ore and the top and bottom of a single, major biotite plagioclase leptite, Ra = 117.5 ~ 136.8MPa, belongs to hard rock. The surrounding rock of the ore body and its top and bottom plates is stable, and the stability of the surrounding rock of the mine section is stable and basically stable.
The geological conditions of the deposit are a simple type of vein deposits dominated by hard, semi-hard block and strip-like rocks. The hydrological conditions of the deposit are simple, the normal water inflow is 729m3/d, and the maximum water inflow is 769m3/d.
In the occurrence of ore body, the main ore body of IV1 is continuous and stable, and there is no phenomenon of bifurcation and extinction along the strike and the tendency. Although the ore body is damaged by the late vein rock, it is local and not destructive. The ore body remains intact and continuous. The ore body is bounded by the 0 line, the south line of the 0 line is steep, 75°～80°, and the part is upright; the 0 line is slowed by the north dip angle, 6°～75°, a small amount is 50°, the ore body is along the strike. There is distortion.
3 mining method selection
According to the technical conditions of the mining and the occurrence of the ore body, the empty field is selected and then the mining method is used for mining. The stope is arranged along the strike. The length of the stope is 50-60m, the height of the middle section is 50m, the bottom column is not left, the top column is 6~8m, the column is 6~8m, and the recovery rate is 82.2%. For ore bodies with a horizontal thickness greater than 8 m, a segmented empty-field mining method (a medium-deep hole ore deposit, accounting for about 35%) is used, as shown in Figure 1, for shallow ore-retaining mining methods for ore bodies with a horizontal thickness of less than 8 m ( About 65%), as shown in Figure 2.
4 mining process
4.1-segment empty field method
(1) The formation of the stope. The stope is arranged along the strike. The length of the stope is 50m, the width is the thickness of the ore body, the height of the middle section is 50m, the top column is 6~8m, and the column is 6~8m.
(2) Precision cutting. The cutting work mainly includes the excavation of pedestrian material patio, sectioned rock drilling roadway, along the vein discharge roadway, the mining road, the mine drainage well, and the cutting patio. The pedestrian material is placed 50m apart in the middle column, and the sectioning rock height is 13~15m. The middle section along the vein is 6~7m high and excavate along the vein discharge roadway and the outburst way. Dig a mine outflow well every 100m.
(3) Mining process. The vertical upward fan-shaped blasthole is drilled with a YGZ-90 rock drill . At the time of mining, the cutting patio disposed in the center of the stope is generally retracted for the two ends. The mining uses a 1.5m3 diesel scraper, and the ore is placed in the middle section along the vein mine car by the mine.
(4) Ventilation of the stope. Fresh air flows through the veins → pedestrian material wells → rock drilling contact roads → upper middle section return air passages.
(5) Main technical and economic indicators. The comprehensive production capacity of the stope is 250-300t/d, the rock drilling efficiency is 30m/shift, the cutting ratio is 21.5m/kt, the scraping efficiency of the scraper is 200t/shift, the loss rate is 20%, and the loss is 20%.
The rate is 14%.
4.2 Bottomless column shallow hole retention method
(1) The formation of the stope. The stope is arranged along the ore body. The length of the stope is 50m, the width is the thickness of the ore body, the middle section is 50m high, the top column is 6~8m, and the column is 6~8m.
(2) Precision cutting. Dig into the pedestrian material patio and contact road, along the vein excavation roadway, mining road, mine drainage, cutting and other roads.
(3) Mining process. The horizontal blasthole is constructed with the YT-27 rock drill , and the blasthole inclination angle is 0°～5°. The layered mining face is arranged in a ladder section, and the layered mining height is 1.8~2m. Manual charging, segmented millisecond blasting, non-conducting squib detonation, and secondary crushing are carried out in the stope. After the mine is out of the mine, the Z-17A rock loader is used for mining. Each time the mining volume is 1/3, each mine wear must be evenly mined to ensure that the ore is evenly lowered and the working face is smooth.
(4) Ventilation of the stope. Fresh wind flows through the veins → pedestrian material patio → rock drilling contact flat road → upper middle section return air passage. Local fan ventilation is used in single-track roadway and difficult-to-ventilate locations.
(5) Main technical and economic indicators. The comprehensive production capacity of the stope: the mine is 100~120t/d, the rock drilling efficiency is 35~40t/(Taiwan·Ban), the cutting ratio is 18.5m/kt, and the scraping efficiency of the scraper is 200t/(Taiwan·Ban). The loss rate is 16% and the depletion rate is 8%.
4.3 Gob area treatment
The goaf is filled with graded tailings and the tailings are filled at a concentration of 70%. The tailings discharged from the plant are graded by a cyclone at a 590m classification station, and the grit above the 38μm level enters the sand storage tank, and the fine-grained tailings overflowing out are returned to the tailings reservoir. The sand is mixed with the mortar to make a mortar with a concentration of not less than 50%, and is transported to the vertical silo of the filling station by a water isolation pump. The upper part of the sand silo is provided with an overflow pipe, and the vertical sand bin is filled and then filled with pulp. According to the requirements of the mining process, after the hydraulic pulping, the sand is made into a mortar with a concentration of more than 70%, and is transported to the underground filling site by gravity.
5 Conclusion
After many years of mining practice, the empty-field post-filling mining method has been gradually improved in the Shangxikeng molybdenum mine. The actual mining technical indicators are: comprehensive cutting ratio of 15.5m/kt, recovery rate of 85.3%, and depletion rate of 10%. The production capacity is 1200t/d, and the maximum mining capacity of the single stope is 600t/d.
Therefore, the empty field post-filling mining method has achieved success in the Shangxikeng molybdenum mine, which has improved production efficiency, reduced the amount of mining and cutting engineering, and reduced the cost of mining operations. It is recommended to continuously summarize the experience in the future mining process, further optimize the design parameters, strengthen the safety production management, improve the efficiency of equipment mining, and fully exploit the potential of filling the mining method after the empty field.
references
[1] Guo Jin Feng. Experimental study on post-filling mining method for segmented empty field [J]. Jiangxi Nonferrous Metals, 2000, 14 (3): 8-10.
[2] Yan Xiaolei, Song Xiaojie. Application of Ling Po filling method will in the iron ore [J] in deep high range subsequent empty field. Nonferrous Metals: Mines, 2013, 65(3): 21-23.
[3] Xie Yongsheng. Sublevel subsequent filling mining method in the study of lead-zinc mine Du Pakistan of [J]. Nonferrous Metal Engineering, 2012, 2(1): 38-43.
[4] Xiao Baofeng, Yao Xiang. Application Test and filling method [J] Deep copper ore ASHELE stage subsequent empty field. Mining Technology, 2006, 6(3): 195-198.
Author: Yun Gang; Fujian Xinhua Engineering Co., Ltd;
Article source: "Modern Mines"; 2016.5;
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