Application of shallow hole mining and mining method in Yaogangxian tungsten mine

The shallow hole retention method is used under the condition that the ore and surrounding rock are moderately stable, and the thickness is from very thin to thick, the steeply inclined ore body has small inclination change, and the ore has no oxidation, agglomeration and spontaneous combustion. The mining process of the shallow hole retention method includes rock drilling, charging, blasting, ventilation, partial ore-mining, and flat field (first processing the working surface pumice ). The comprehensive method of retaining ore is a deformation scheme suitable for thin ore bodies with inclination angle greater than 30° and less than 55°. Due to its adaptability and simple equipment (air-leg rock drill and electric raft), it is widely used in small and medium-sized mines in China. .
1 Overview Yaogangxian mining non-ferrous metal mining industry limited liability company located in Yizhang County, Chenzhou City, Rucheng County, three counties at the junction of Zixing, leaning riding Nanling Mountains northeast ridge of the field. Mine began mining in 1914, now mining capacity of 400,000 t, an annual output of wolframite concentrates more than 2000 t. The reserves of tungsten ore in the mine are 1.78 million tons, with an average grade of 0.25%. The ore body is oriented at 285° to 315°, tending to the southwest or northeast, with a dip angle of 60° to 80°, a few below 60°, and a thickness of 1 to 40 m. The ore body is composed of large veins and fine veins, with a length of more than 1400m and a depth of several hundred meters to 1300m.
There are 26 middle sections of Yaogangxian Mine. At present, the middle section of the main mining is 23 mid-range (550m level) and 24 middle section (510m level).
Test stope range: upper limit 23 middle section 501 8-S (level +550.845m), lower limit 24 middle section 501 branch 8-S (level +506.343m). The starting mining position is the top plate of the lower contact road of the stope, and the final mining position is the top column bottom plate of the stope, which can take a total height of 37.0m. The length of the advancement along the strike direction is 44.5 m, and the length of the working face is 89.7 m.
The mine vein of this mining face is 24-501 branches and 8 veins of the lower vein, and 23-501 branches and 8 veins of the upper and middle veins. The vertical height of the upper and lower veins is 44.1m, and the inclined length is 47.7m. 24-501 8-pulse thickness is 0.25m, and 23-501 8-pulse thickness is 0.50m. The upper middle section of the 23-501 branch 8-5 is adopted as the mining stope, and has no effect on the lower middle section mining.
There is no mining in the lower middle section of 25-501, and there is no impact on the mining of this working face. Platinum hardness coefficient of ore: 10-12 for ore, 8-10 for granite. The weight of ore in the middle and above is generally 2.64t/m3, of which 2.76t/m3 is in the meteorite area; the middle part is 20~26 in the deep, Yangmei The average weight of the ore in the middle section of Lingshan District was 2.66 t/m3. The ore has a humidity of 0.057% and a looseness factor of 1.6, of which 1.45 in the Dayanen area and 1.65 in the meteorite area. The ore angle of the ore with a particle size of 50 mm is 45°, and the ore is smaller than 10 mm. The angle of repose is 35° to 37°.
2 mining process
The ore body of the 2.1501 8-pulse stope is located between the middle section of the 23rd and the middle section of the 24th. The surrounding rock of the ore body is mainly granite, Devonian hopping sandstone and Cambrian shallow metamorphic rock series. It is a stable, non-weatherable mineral composition, and has a tighter structure and good stability due to alteration. Its ultimate compressive strength is generally greater than 60 MPa, and the internal friction angle is above 80°. It belongs to the hard rock group, ore body and circumference. The boundaries between the rocks are obvious. The thickness of the ore body is small, and the thickness of the thin ore body is generally stable. The data revealed by a large number of tunnels in the mine indicate that the stability of the ore and surrounding rock is very good, and there is generally no bad engineering geological problem. Most of the tunnels do not need support. According to the statistics in the middle of the 19th section, the total length of the support in the tunnel of nearly 2000m is less than 50m, indicating that the ore is stable.
2.2 The choice of mining technology According to the mining experience of this mine and similar mines [1-8], the economic value of the nuggets when using the intra-pulse transport flat roadway is 2,380,400 yuan, which is 23 more than the secondary cutting plan. .66 million yuan. Therefore, it is decided to arrange the transportation along the vein at the contact line of the lower part of the ore body, and a small chute is connected to the stope every 5m. In the inter-column, the pedestrian uphill and the contact road leading to the stope are arranged, and the upper stage is transported. The lane returns.
2.3 broken veins The method of breaking the veins of the working face is to break the veins, and each of the ore blocks is equipped with a 7655 and YSP-45 gas-leg rock drill .

According to the rock drilling equipment, the diameter of the blasthole is 38mm, the 7655 is used to drill the horizontal hole and the inclined hole, and the YSP-45 is used for the chiseling up hole. In order to ensure that the height of each collapse is 2m, the blasthole is 0.2m deep, and the total blasthole depth is 2.2m. The blastholes are arranged in parallel staggered, collapsing to the side, taking 1m for the resistance line and 1m for the hole spacing. The blockage length is 0.5m. The rock anti-water ammonium lanthanum explosive was selected, the charging density was 0.78kg/m3, and the blast hole per metre was 2.43t.
2.4 ore mining The mining method of mining and mining includes gravity ore mining, electric shovel mining, rock mining outlaying, scraper mining, and vibrating ore mining. According to the angle of repose of the ore, the mining site uses gravity to mine.
2.5 Roof control The place to be supported by the stope is almost neglected, and the shed-type support is used in the lower middle section. The stope funnel uses a safety baffle in the goaf.
During the initial pressure and periodic pressure, if necessary, in the lower middle section, the roof of the roadway is transported by pit wood or U-shaped steel to form a braided supporting structure.
2.6 Management of goaf area (1) The mine shall formulate a unified plan for the treatment of empty areas according to the distribution of the goaf, and handle it in a planned and step-by-step manner.
(2) The mine shall determine the maximum allowable quantity and retention period of the empty area according to the stability of the ore and the mining method used, and report it to the competent department for approval. For empty area treatment, methods such as caving surrounding rock, filling and sealing, and isolation should be adopted according to the specific conditions.
(3) The method of treating the goaf by caving surrounding rock is suitable for the surface to allow for subsidence, and the movement of the rock after the collapse will not affect the surface.
(4) In order to control the range of ground pressure activities and prevent large-scale collapse of rock formations, a goaf treatment method for isolating or supporting ore (rock) columns may be used.
(5) The treatment method of the closed goaf is mainly used for the isolated goaf where the surface is allowed to fall, and it must be isolated from the passages of other mining areas.
3 Conclusion According to the geological characteristics of 501 8 ore bodies, the mining method of intra-pulse transport flat-hole shallow-hole mining is adopted, which saves the loss rate and production cost of the gangue volume of the ore, which is beneficial to the development of mine mining. Contribution.
references:
[1] Huang Jiaxian, Song Yi, Wei Liuyong, et al. Optimization of shallow hole retention method for coral black tungsten ore [J]. Mining Technology, 2015, 15 (01): 10-13.
[2] Wang Hanzhang. The shallow hole retention method in the Yuquanba gold mine should be [J]. Mining Technology, 2015, 15 (02): 22-24.
[3] Ma Kaichuan. Study on optimization of structural parameters of stope in a shallow hole retaining ore method in a mine [J]. Hunan Nonferrous Metals, 2015(04): 7-10.
[4] Jiang Yadong. Application of shallow hole retention method optimization scheme in thicker ore body [J]. Xinjiang Nonferrous Metals, 2014(S2): 53-54, 57.
[5] Feng Huiqiang. Application of shallow hole retention method in Xiajiao Mine [J]. Mining Technology, 2014, 14 (05): 5-6.
[6] Wang Kehong, Chen Xingming. Improvement and practice of the bottom structure of shallow ore-retaining method in thick ore bodies [J]. Mining Research and Development, 2016, 36(01): 19-22.
[7] Yang Fujun, Gao Haichuan. Research and exploration of high efficiency shallow hole retention method [J]. Metal Mine, 2007 (06): 84-86.
[8] Shi Naimin, Chen Zhiqing. The application of the pit-bottomed shallow hole retention method in Wutun Mine [J]. China Mining, 2010 (07): 75-76, 93.
Article source: Mining Technology; 2017, 12(1)
Author: Zhang Zhixiang; Hunan Yaogangxian Mining Co., Ltd., Hunan Chenzhou City 424 209
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