Advanced Technology for Comprehensive Utilization of Safe and Efficient Filling and Mining in Lushan Phosphorus Mine

The high phosphorus Fanshan mine, the mine is divided into low-water boundary East and West, Eastern region of low water, the aqueous layer was coated on the high pressure West Q2. Because the aquifer is the living and agricultural water of nearby residents, and the road surface, cultivated land and orchard are not allowed to collapse and destroy the Q2 aquifer, the mine has not been mined. Mine mining area caused by something obvious imbalance in the rate of decline, resulting in mine reserves accounted for more than 2/3 of the Western phosphorus iron ore development and utilization of resources can not, greatly reducing the mine life, a direct impact on continuing operations and mine development. According to the original design, the East District will be exhausted by 2017, and the development of the Western District has reached the current 900,000 t/a in 6 years. The Western Region Filling Mining Technology has realized the protection of groundwater resources and the ecological environment while achieving the Safe and efficient mining, the long-term non-exploitable West Phosphorus ore resources (reserved resource reserves of about 32 million tons) have been fully exploited and utilized, significantly improving the economic benefits of the mine, and highlighting the sustainable and harmonious development of the Laoshan phosphate mine. effect.
1Western area filling mining method and process optimization process
In order to make the mine continue to develop steadily, the mine proposed mining the western part of the ore body by changing the mining method. That is to say, the dredging method of the original design of the mining reform in the Western District is the filling method, which protects the water resources and the surface environment while ensuring the safety of mining. The Laoshan phosphate mine has been exploited in the eastern region for more than ten years. In practice, it has accumulated more research results on the variation of rock and rock, the mechanical properties of rock, and the first-hand data such as the variation of the bedrock surface, the differentiation zone and the thickness of the Q2 aquifer in the western region. Have the technical advantage of implementing filling mining.
1.1 Western District Mining Method Technology Optimization Process
The design and construction of the project supporting project began in the West District in 2008. The mining method test began in July 2010. The progress of the test work is not smooth. The main performance is the bedding, joints and fissures of the rock, the roof of the stope is not stable, and the support The workload is large. If the workers work under the large exposed roof, the safety conditions of the operation are poor. Therefore, the mining process and the layout of the stope have been forced to change many times, and the “point column” has been changed to “vertical ore body orientation”. The continuous column of the room column filling mining method", because the exposed area of ​​the roof is changed to "upward horizontal layering two-step filling method", the first step of the mine is 8m wide, and the two-step mine is 7m wide, but this type The mining method still has personnel working under the large exposed roof, and the working conditions have not been improved. Later, the “upward horizontal stratification two-step filling method” was changed to “upward horizontal stratification high and low approach” (see Figure 1) and “segmented diamond mining filling method”. Starting from July 2011, the “Upward Horizontal Stratified High and Low Approach” filling method mining method experiment was carried out at the 437 level 8-18# ore block; after more than 2 years of testing, the operating conditions were compared in the first layer of mining. Safety, the amount of support is relatively small, but when the second layer is recovered, the top layer is exposed to a large area due to the low coverage of the first layer. The ground pressure is severe, and every 2m of excavation requires support. The efficiency is low, the safe working conditions are poor, the mining cost is high, and the mining method is forced to change. At the same time as the upper horizontal stratified approach mining method test, the “sectioned diamond mining post-filling mining method” test was carried out in the middle section of the 425 section 4-8#. After nearly 2 years of experiments, it was determined. This mining method is more suitable for the ore rock conditions of the Laoshan phosphate mine.

1.2 Sectional diamond-shaped mining filling method
(1) Adopting the outer pulse slope of the lower plate, the main mining and cutting projects include: segmentation along the vein contact road, section mining stopway, 1#, 2# rock drilling, mining approach, mining contact Roads, filling ventilation and returning wells, ore chutes, cutting wells and cutting wells. The layout of the mining project first determines the location of the segmented veins along the veins. Each of the ore blocks is arranged with two chutes, and the chutes are arranged at the lower and outbound contact points to shorten the shunting distance during the excavation and mining. Improve the efficiency of mining. Then, each ore block constructs a stopway connecting road to the ore body. After the contact road is in place, 1 to 2 rock drilling lanes are arranged. The first section is arranged with a rock drilling lane, and the upper two sections are arranged with two rock drilling lanes. The upper and lower sections of each ore block correspondingly form a diamond-shaped mining unit. The specific arrangement is shown in Figure 2.
(2) The ore blocks are arranged along the ore body, with a length of 50-60 m, a width of the ore body horizontal thickness, 18-20 m, a middle section height of 45 m, a segment height of 10-12 m, and a 8 m wide between the nuggets. The pillars are arranged in the inter-column between the upper and lower middle sections for ventilation, filling and drainage. In the ore block, three diamond-shaped mines are arranged along the section from bottom to top along the ore body. The height is 24m and the length is 25~52m. The width is the horizontal thickness of the ore body. The bottom structure is arranged at the bottom of the diamond-shaped mine, 6-7 excavation roads and a rock drilling road, forming the bottom structure of the ore. Due to the limitation of the mine rock drilling equipment and charging equipment, in the middle of the lower two diamond-shaped mines Design auxiliary rock drilling section, two section rock drilling road rock drilling, bottom rock drilling lane cutting "V" type trench as the mining roadway, combined with the outbound ore mining, greatly improving the recovery rate; The residual ore is cleaned by the remote-controlled scraper; the mine is filled immediately after the mine is finished, the empty roof time is not more than 4 months, and the roof is strictly connected. After the final filling of the filling body, the sub-section mining room is returned. The next charging cycle. Before the mining of the mine, the reinforced roadway is arranged along the lower part of the upper middle section of the ore body, and the long anchor line is arranged along the entire length of the mine from the inclined direction of the vertical ore body of the reinforced roadway.

During the test, the structural parameters optimization and technical innovation of the stope were continuously carried out. Optimized the mining parameters, bottom structure, filling project, filling sand-to-sand ratio, cutting ratio, roof pre-supporting, and mining equipment improvement for segmented diamond mining method, reducing mining ratio and mining cost, and improving The mining efficiency and the safety of the mining are optimized; the filling parameters and the filling sand ratio are optimized, the filling top rate is increased, and the filling cost is reduced.
After on-site industrial trials and continuous optimization of mining methods in recent years, the Western Region Filling Mining Test has achieved success, not only achieving the purpose of high-pressure underwater safe mining in the Western District, but also gradually optimizing mining methods, reducing mining costs, and improving A lot of research work has been done on production efficiency. By the end of 2015, the total recovery of industrial ore bodies in the western region was 2.512 million tons, and the mineralized surrounding rock was 857,700 tons, which laid the foundation for the improvement of mine production capacity and sustained and stable development. The mining cost in the West District decreased from an average of 150 yuan/t in 2012 to 90 yuan/t in 2015. The filling cost has been reduced from 25 yuan/t in 2012 to 12 yuan/t in 2015. The main indicators are shown in Table 1.

Key technology and equipment for 2-section diamond mining filling method

(1) Safe and reasonable thickness determination technology for security pillars. Based on the physical and mechanical parameters test of mineral rock, engineering geological survey research, rock mass quality evaluation and rock mechanics parameter engineering treatment, through the three-dimensional stress analysis numerical simulation software of geotechnical engineering, the reasonable safety thickness and east-west area of ​​the roof isolation pillar The optimization of the width of the isolated pillar is carried out. It is determined that the numerical simulation result of the thickness of the roof pillar of the three-layer ore body is 121m; the numerical simulation result of the thickness of the roof pillar of the two-layer ore body is 76m. Through numerical simulation, the minimum safe width value of the isolated pillars in the east and west areas is 16.46m.
(2) Security pillar reinforcement technology. In order to prevent the phenomenon of spontaneous layering after the excavation of the ore body, in the true thickness direction of the vertical ore body at the bottom of the security pillar, according to the row spacing of 3m, each row of 3 long cable anchors with a length of 18~25m is used to strengthen the security. Pillar strength.
(3) The original geological exploration drilling and sealing inspection and plugging technology. The original geological exploration has passed through the aquifer and ore body due to the control of the ore body. If the original geological borehole is not sealed or the sealing quality is unqualified, the geological borehole will become the water guiding channel, posing a threat to the production of the stope. Hand-held GPS is used to locate the surface of all geological exploration boreholes, and the boreholes whose unsealed or unsealed quality is unqualified are screened and treated by cement grouting on the surface.
(4) Geophysical exploration and water guiding structure technology. In addition to geological exploration boreholes that are unsealed or unqualified in sealing quality may constitute a water-conducting threat, geological structures are the biggest hidden dangers of possible water-conducting; electrical methods are used on the surface to identify larger possible water-conducting structures, combining The underground mineway engineering treats it: reserve a protected mine (rock) column.
(5) Filling and topping technology. The mined-out area formed after the mining of the segmented diamond-shaped mine is mainly used to fill the borehole every 15m from the upper filling roadway to ensure multi-point feeding, multiple filling and sub-leveling of the filling slurry; Pulp concentration, appropriate increase of sand-sand ratio; construction of filling roadway in advance at the top of the mine, after the blasting of the stope and the filling of the roadway, using the filling slurry and the height difference of the goaf to improve the roofing rate.
(6) Application of high-precision detonating detonator and blasting vibration tester. The high-precision detonating tube is used to blast the stope and the blasting vibration tester is used to test the blasting vibration regularly. The blasting parameters are continuously optimized, the single-shot dose in the western area is effectively controlled, the blasting effect is improved, and the surface residential area and Q2 are greatly reduced. The disturbance of the confined water layer ensures the safe recovery of the ore body in the western area.
(7) Introduction and application of remote-controlled forklifts. In view of the mining property of the segmented diamond-shaped mining method in the Western District, after the mining of a single ore block, the exposed area of ​​the roof is about 900m2, and the length of the empty zone is 30m. At this time, if it relies solely on the electric scraper for mining, In the case of entering the empty area, the loss rate is high and the demand for mining is not met. In response to this problem, the domestic remote-controlled scraper has been introduced, which greatly improves the ore recovery rate, improves economic efficiency, and ensures the safety of underground workers. .
(8) Application of the empty area detector. The Lushan Phosphate Mine introduced the VS150-MK3 3D laser scanner in January 2014. After a period of practical application, the 3D laser scanning technology has a good guiding significance for mine production and safety. The 3D laser scanner can accurately measure the volume of the goaf, and provide technical support for the improvement of the next filling design and the calculation of the filling amount and the accurate calculation of the C material amount, as well as the optimization of the blasting parameters and the control of the depletion rate.
(9) Introduction and application of imported and domestic hydraulic trolleys. Since the hole equipment in the original construction is YGZ-90 drilling rig , the precision of the hole in the construction is poor, the efficiency is low, and there are many large blocks. In order to solve this problem, the imported hydraulic simber1253 rock drilling rig with higher precision in the construction hole is introduced. Domestic Huatai HT rock drilling trolley, after the introduction of equipment, the practice liquid
The rock drilling efficiency of the 1253 rock drilling rig is 120m/shift, and the domestic Huatai rock drilling rig is 100m/shift. The construction efficiency of the middle hole is greatly improved, the precision of the deep hole in the construction is improved, and the blasting effect is improved.
3 conclusions
(1) The research proposes the diversified protection of Q2 aquifer mining technology by filling mining, pillar support and displacement deformation monitoring. In this study, an appropriate amount of security pillars are left between the mining area and the middle section, which can effectively support the surrounding rock and the roof of the stope and control the displacement deformation. Displacement and deformation monitoring can verify the support effect of the filling body and the pillar, and predict safety hazards.
(2) Research and development of the segmented diamond-shaped mine tailings cement filling mining method, which is a mining method researched and developed in combination with the caving method and filling method and the ore body shape of the western part of the Lushan Phosphate Mine, which is the first in China and abroad. The innovation of the mining method makes full use of the mining structure of the sub-column sublevel caving method, realizes the segmental empty-field mining, and fills the empty space after the helium. It has the mining high efficiency of the caving method and the safety of the filling method.

(3) The mining unit is designed as a diamond block. The shape of the roof of the empty area after the mining is approximately arched, which makes use of the good structure of the arched roadway and improves the stability of the roof of the mine. The computerized three-dimensional finite element numerical simulation method was used to establish the mathematical model of the underground mining of the Laoshan Phosphorus Mine. The possible parameters of the stope structure, the exposed area of ​​the goaf, the size of the pillar, the thickness of the roof insulation layer and the stress during the mining process, The numerical simulation analysis of strain and displacement changes provides a theoretical basis for mining method selection, optimization of mining sequence and determination of roof isolation thickness. Through numerical simulation and experiment, the safe size of the pillar, the main structural parameters of the mining method and the filling process suitable for the mining method are determined, which effectively prevents the damage caused by the top high confined aquifer.
(4) The mining method equipment and personnel are not directly operated under the top plate of the exposed area with large exposed area, and the operation safety conditions are good; the production efficiency is high, the labor intensity is small; the filling cost is low, the filling top rate is high, and the quality is good. The use of remote control ore mining equipment enables safe and efficient mining under open field conditions.
(5) Established a ground pressure monitoring network system suitable for the characteristics of the Laoshan phosphate mine. Including uphole underground settlement observation system, microseismic monitoring system. It provides a reliable basis for the ground pressure control and safety management of the Laoshan Phosphorus Mine.
(6) Research on wear-resisting technology of shaft filling drilling pipeline, completely solve the problem of fast filling and drilling wear, improve the service life of filling drilling, and ensure the timeliness of filling.
(7) Extend the service life of the mine and maintain the harmonious development of the enterprise and the mining area. With the success of mining in the western region in recent years, the Lushan Phosphate Mine has increased the mining capacity by 32 million tons. According to the current mining scale, the mine service life can be increased by 14a. More importantly, it can stabilize the work and life of employees and enable the workers to live and work in peace. Realize the harmonious development of employees and enterprises.
The mining area is surrounded by the National Grape Planting Industry Demonstration Park. It is also a tourist protection zone with a long history and culture. The West District filling method can effectively control the large-scale settlement and collapse of the roof of the stope to prevent the destruction of the Q2 aquifuge and the roof. It can effectively protect the safety of high pressure water, protect groundwater resources and ecological environment, so that the surrounding environment of the mining area is not destroyed, and the surface cultivated land and road surface do not settle. At the same time as the safe and efficient mining of the ore body in the western part of the Laoshan Phosphate Mine, the demonstration project has positive practical significance for the ecological environment protection of the mining area.
The test of the Q2 high-pressure aquifer mining method in the western part of Lushan Phosphate Mine was successful in domestic chemical mines or other similar mining industries, such as gently inclined, moderately stable surrounding rock, ore ore with other medium or thicker conditions. Mines with broken conditions can be promoted or borrowed.
Segmented diamond-shaped mine filling method mining, low production cost, safe and efficient, easy to master the process, convenient production organization, providing mining experience for similar mines at home and abroad.
references:
[1] Liu Tongyou. Filling mining technology and application [M]. Beijing: Metallurgy Industry Press, 2001.
[2] Qiu Xiande, Huang Mukun, Wang Xinfei, et al. Application of numerical calculation in stability evaluation of goaf [J]. Mine Pressure and Roof Management, 2002, 19(4): 105-107.
[3] Zhang Ronglin. The stability of the goaf in the northern mining area and its impact on the safe mining of the lower ore body [J]. Metal Mine, 2003, 5(2): 10-11.
[4] Goode, Li Xibing. Modern metal deposit mining science and technology [M]. Beijing: Metallurgical Industry Press, 2006.
[5] Changsha Mining Research Institute Co., Ltd. Summary report on research on safe mining technology in the west of Lushan Phosphate Mine [R]. Zhangjiakou: Hebei Lushan Phosphate Mine Co., Ltd., 2012.

Article source: Mining Technology; 2017.17(2)

Author: Lu Shu Ping, Chang Wei, Zhao, Wu Xu, WANG Chao; Fanshan phosphate Hebei Co., Zhangjiakou City, Hebei 075 641

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