Application of post-mortar filling mining method in stage mine molybdenum mine

1 mining technology strip

The Batou molybdenum mine is located at a distance of about 22km from the northwest of Gutian County, Fujian Province, and is under the jurisdiction of Fengpu Township. Geographical coordinates: east longitude 118°39'9.55"-118°40'22.7", north latitude 26°45'42.5"~26°46'48.14". The mining area belongs to the middle and low mountainous landforms. The main ridges are NW-near SN. The elevation elevation is 1113.8m, the lowest is 725m, and the relative height difference is 388.8m. The terrain is high in the northwest and low in the southeast. The terrain is deep and the slope is large. It is V-shaped and U-shaped. The valleys are covered with cliffs and the vegetation is extremely developed. There are 83 ore bodies in the mining area, including 9 main ore bodies, numbered I#, II#, III#, IV#, V#, VI#, VII#, IX#, XI#, sporadic industrial ore bodies. 37, sporadic low-grade ore bodies 37.
The I#, II# and IX# ore bodies are large in scale, and the distribution along the strike and tendency is relatively stable. The inclination angle of the ore body is 10°～35°, the overall inclination angle is about 12°, and the thickness changes greatly. Ⅰ # ore body is the most important area of ore, rock occur in the upper, industrial seam (332) + (333) a molybdenum metal resources 1051.54t, accounting for 67.20% of the total amount of resources mining, thick as 5.05 ~ 17.63m, the average thickness is 12.02m, of which the single-layer single-layer sees the maximum thickness of 35.26m. The molybdenum ore body is distributed in the plaque-like biotite monzonitic granite body, and the surface is poorly exposed, mainly concealed ore body. The surface of the II# ore body is well exposed in the eastern part of the ore, which is the marked mineral layer. Compared with the mining area, the ore layer is distributed back-to-back between the east and west ore sections. The ore deposits in the western ore section are controlled by the primary layer joints of the north-western wing of the dorsal shape. Most of the dip angles are gentle, and they are soothing and wavy. There are branching and compositing phenomena along the strike and the trend. The whole layer is layered and lenticular along the granite primary layer. The joint distribution, the mineralization intensity is related to the degree of rock fragmentation and the degree of joint fissure development.
The rock of the ore-bearing ore and the surrounding rock of the top and bottom plates are generally porphyry medium-fine-grained biotite monzonitic granite, which belongs to the hard engineering geological rock group. According to the drilling exposure, the core is generally long columnar and columnar, with good rock integrity, average RQD value of 81%, rock compressive strength greater than 60MPa, rock mass quality index of 0.345, and rock mass quality is excellent. The tunnel reveals that the ore body and its surrounding rock are generally stable and have no support phenomena. The overall engineering geological conditions are simple.
2 mining method selection
If the caving method is used for mining, in order to form normal mining conditions and prevent a large number of cavings from causing safety accidents, the upper part of the caving ore layer shall be covered with rock as a covering layer. Due to the gentle dip angle of the ore body, a rock cover layer corresponding to the horizontal area of ​​the ore body shall be formed. According to the mine data produced by the domestic caving method, the normal thickness of the rock cover layer is about 20 m, while the average thickness of the main ore body is only 12.02 m. The amount of rock blasting is basically the same as that of mining blasting. The ore mining cost is high and the efficiency is low. The surface forest resources of the mining area are rich. The economic plants are mainly pine, cedar and bamboo, and the surface is not allowed to fall. Therefore, this method is not applicable.
According to the occurrence characteristics of the ore body and the mining technical conditions, the I#, II#, IX# ore body is the first mining object, and the ore body with a thickness of not less than 8 m is selected for mining in the stage mining house [1]. Figure 1), this part of the resources accounted for about 90% of the design utilization of resources; for the thick 4 ~ 8m ore body, the shallow hole room column method, the part of the resources accounted for about 10% of the design resources.

3-stage mining room post-filling mining method
3.1 Stope components
The mine room is arranged perpendicular to the direction of the ore body, and is recovered in two steps, one step back to the mining column and two steps back to the mining room. The mine is 20m wide and the pillar width is 10m. The length is the horizontal thickness of the ore body. The height is the vertical thickness of the ore body. Each of the 4 mines is divided into 1 panel. It is first returned to the mining column. After the mining is completed, the tail rubber is filled. After the tail rubber filling body reaches the curing period, it can be returned to the mining room, and the mining room is filled with graded tail sand after mining.
3.2 mining cutting
Dig into the transport lanes on the upper and lower plates of the ore body, perpendicular to the upper and lower discs, and the roadway for the excavation and scraper of the roadway (the ore-penetrating vein), and the excavation and excavation approach along the ore body along the ore roadway, the distance between the roads is 6 ~8m, using a layer of rock drilling roadway to dig the trench roadway. A manhole equipment well and a stope mine are drilled in the center of the mine, and the section rock drilling roadway is drilled every 10m from the pedestrian equipment well. The cutting patio is arranged in the middle part of one side of the mining room, and the cutting patio is used as a free surface to blast the cutting groove along the width direction of the mining room. The Kailuo Ditch drills the upper fan-shaped blasthole in the gully tunnel, which is formed in the same segment as the falling mine.
Taking the 795-1906-S stope as an example, the total engineering volume of the stope is 664m, the cutting ratio is 4.8m/kt [2], and the amount of cutting work is shown in Table 1.

3.3 mining mining
Advance from the side of the mine to the other side along the length of the mine. Using the YGZ-90 rock drill with CTC141 rock drilling rig to drill the upper fan-shaped middle hole in the section rock drilling roadway, the hole diameter is 55mm, the minimum resistance line is 1.5m, the hole bottom distance is 2m, the hole hole angle is 42°, the blast hole The row spacing is 1.5m, the ammonium explosive is used, the FZY-1 charge is charged, and the continuous charging method is coupled. For hard ore rocks, it is necessary to block with the mud, the length of the mud blockage is not less than 0.8m, and the charge density is 1g/cm3 [3]. The cutting groove is used as the free surface for blasting, and the blasting is performed for 3 to 5 rows of blastholes. The millisecond differential blasting method is adopted, and the non-conducting squib detonator is detonated. In order to ensure the quality of ventilation, the middle and deep holes in all sectioned rock drilling roadways are completed and qualified by geological, measuring and mining technicians before the medium and deep hole blasting charge design [4].
3.4 mining site mining
The EST-2D electric scraper is used to mine the ore and transport the ore to the ore slip. The scraper transport distance is no more than 200m [5]. In the process of mining, if a large ore is encountered, it shall be treated by blasting, and the secondary blasting shall be carried out in the exiting ore of the stope.
3.5 Gob processing
After stope mining is completed, use beneficiation plant tailings backfill mined-out area, before filling, good layout first drain port and haulage tunnel leading to the middle of all of the stope block of reinforced concrete for export. The pillars are filled with a 1:5 lime sand ratio, and the mine is filled with graded full tailings.
4 Conclusion
(1) After the implementation of the post-filling mining method in the stage mine, the mining capacity can reach 3000t/d, and the mining efficiency is guaranteed.

(2) Rock drilling and blasting operations are carried out in the roadway, and personnel do not need to enter the operation below the empty area to avoid the occurrence of safety accidents.
(3) The implementation of the post-filling mining method in the stage mine has not only improved the ore recovery rate, but also effectively controlled the ground pressure activities and saved the tailings storage capacity.
(4) According to the effect of medium-deep hole blasting, gradually adjust the row spacing, hole bottom distance and single hole charge, and gradually optimize the blasting parameters to obtain the best blasting effect.
(5) For the two-step mining recovery, it is recommended to use Orica high-precision detonating tube per-hole detonation technology to improve the blasting effect, reduce the damage of the blasting vibration to the tail rubber filling body, and reduce the ore caused by the filling body. Secondary depletion.
references
[1] Li Gongtang. Wuyang Iron ore mining stage subsequent room filling mining method of application [J]. Modern Mining, 2014 (11): 41-42.
[2] Yin Yiqiao. Preliminary study on post-filling mining method for segmented empty field [J]. Nonferrous Metals: Mine Section, 1997 (11): 33-35.
[3] Wang Xiaofeng, Wang Weidong, Zhang Huatao, et al. Measures to improve the quality of deep hole blasting in section rock drilling [J]. Henan Science and Technology, 2011 (8): 16-19.
[4] Xie Yongsheng. Sublevel subsequent filling mining method in the study of lead-zinc mine Du Pakistan of [J]. Nonferrous Metals Engineering, 2012(2): 17-20.
[5] Guo Jinfeng. Experimental study on post-filling mining method for segmented empty field [J]. Jiangxi Nonferrous Metals, 2000 (9): 5-8.