Application of room and pillar mining method of gold mining are: Xiangxi gold mine, gold mine in Zhangjiakou, Tongguan gold mine, Spirit Lake gold mine, gold and other white male. According to the data of 1987 and the proportion of the application method of gold mines, the amount of mined minerals is 9.1%.
I. Technical conditions for mining
The main mining technical conditions for the deposits of the gold mines using the room and pillar method are listed in Table 1.
Table 1 Technical conditions for mining of the application of the pillar method
Mine name | Ore body | Surrounding rock | Lower wall rock | ||||||
Thickness / m | inclination /(°) | f | Stability | Gold grade /g·t -1 | f | Stability | f | Stability | |
Xiangxi Gold Mine Woxi Mining Area | 3 to 10 Average 4.5 | 20~30 | 8~12 | stable | 3 to 5 | 4~7 | Medium stability | 4~7 | Medium stability |
Linghu Gold Mine | 0.3 to 11.94 Average 2.63 | 25~30 | Medium stability | 5.39 | Unstable | Unstable | |||
No. 505, No. 1498mII, Shaoguan Gold Mine | 7~15 | 15 | 8~12 | Medium stability | 7.89 | 12~14 | Medium stability | 12~14 | Medium stability |
Shaoguan Gold Mine No. 401 vein 402-I Nugget | 0.9 | 8 | 8~10 | 5.11 | 10~12 | Medium stability | 10~12 | Medium stability | |
Large platinum mine | Average 1.5 | 10-20 | 8 | stable | 6 | 8 | stable | 8 | stable |
Zhangjiakou Gold Mine Dongkeng 1404m9 block | 0.6 to 1.6 | 6 to 15 | 13 | Medium stability | 8.53 | 4~6 | Medium stability | 4~6 | Medium stability |
Zhangjiakou Gold Mine Dongkeng 1357m5 block | 5.2 | 6 to 15 | Unstable | 3.62 | Unstable | Medium stability | |||
It can be seen from Table 1 that the ore body mined by the room-column method includes, in terms of thickness, extremely thin ore bodies (such as Shaoguan Gold Mine No. 401 No. 402-I ore block) and thin ore bodies (most mines in the table). And medium-thick ore bodies (such as No. 505mII in No. 505 of Shaoguan Gold Mine, 1357m5 in Dongkeng, Zhangjiakou Gold Mine, etc.); from the inclination of the ore body, they are all gently inclined; from the stability of the ore, most of them are medium Steady or stable, but also unstable.
Second, mining method structural parameters
The main structural parameters of the gold mine house column method are listed in Table 2.
Table 2 Structural parameters of room and pillar mining method
Mine name | Mine layout the way | Mine size (length × net width) / m × m | Mine room column | Top column / m | Bottom column / m |
Xiangxi Gold Mine Woxi Mining Area | Mine shaft Tilt along | 55～60×5 | Intermittent pillar 3m × 4m, 5m along the slope | no | Oblique length 5 to 7 |
Linghu Gold Mine | Mine shaft Tilt along | 50～60×10～12 | 2.5 | 3.0 | |
No. 505, No. 1498mII, Shaoguan Gold Mine | Mine shaft Tilt along | 32×12 | Continuous pillar width 7m | no | |
Shaoguan Gold Mine 401 No. 402 -I Nugget | Mine shaft Tilt along | 60×7.5 | Continuous pillar width 0.5 to 1 m | ||
Large platinum mine | Mine shaft Along the way | 30×4 | Intermittent pillar 2m×2m Pole spacing: 5~6m | 3 | 5 |
Zhangjiakou Gold Mine Dongkeng 1404m9 block | Mine shaft Along the way | Mine net width 6 ~ 8m Mine area 100~120m 2 | Intermittent pillar 2m × 2m ~ 2m × 3m, spacing 2m | ||
Zhangjiakou Gold Mine Dongkeng 1357m5 block | Mine shaft Tilt along | (5 to 22) m to (4 to 12) m | Intermittent pillar 5m × 5m spacing 5 ~ 8m | 4 | 6 |
It can be seen from Table 2 that the layout of the mine is divided into two types according to the relationship between the long axis and the orientation and inclination of the ore body. The net width (span) of the mine is 4 to 12 m, and the area of ​​the mine is 100 to 400 m 2 . The stability of the roof is related to whether or not the anchor is used. There are continuous or intermittent pillars between adjacent mines.
Third, the mining process
The mining process and related parameters of each mine room column are listed in Table 3.
Table 3 Mining technology of room and pillar mining
Mine name | Recovery order and promotion method | Fall mine | Mining | Roof management |
Xiangxi Gold Mine Woxi Mining Area | Layered mining when the thickness of the mine is greater than 5m. The working face of the step is inclined from the top to the bottom. The lower layer is 3 to 4.5 m ahead of the mining. When the thickness of the mine is less than 5m, the bottom layer (2m high) is taken last time. | Shallow-eye drop mine, eye depth 2 ~ 3m, W = 0.8 ~ 1.2m, blasthole parallel to the bottom plate, plum-shaped arrangement | Mining with 30kW electric raft | Mainly rely on the pillars on both sides of the mine to maintain the roof. Retain temporary pillars in case of faults or local instability, or anchor reinforcement |
Linghu Gold Mine | The horn type working face is inclined from the top to the bottom. | Shallow eye drop mine. The direction of the blasthole is at an angle of 45° to the centerline of the mine. | With 30kW electric raft, the bucket volume is 0.26m 3 | Use wedge-type anchor bolt to protect the top anchor rod length 2m, bolt net degree 1m×1m |
No. 505 vein of Shaoguan Gold Mine No. 1498mII | First cut the top of the mine and anchor the stalk, then stratify back from the bottom to the mining room, and finally return to the mining column on both sides of the mining room. | Use YGZ-90 rock drill to drill the center deep hole, fan-shaped arrangement, forward tilt 75°, W= 1.6m, hole depth less than 10m, aperture 60mm, manual charge, non-electric differential detonator and detonating cord double detonation, each blasting 1 to 2 rows | Most of the ore (69.1%) was thrown into the ore trench during blasting, and the remaining ore was discharged by electricity before blasting. | The mine has been cut and bolted before mining. Bolt mesh (1~1.2) m×1m, anchor is expanded metal anchor |
401 No. 402-I Nugget, Shaoguan Gold Mine | The trumpet-shaped work surface is tilted back and forth from the top to the bottom. | Shallow-eye shallow mine, the angle between the blasthole and the long axis of the mine is 42°, the depth of the eye is 3m, the row spacing is 1m, the eye distance is 0.5m, the non-conducting squib is slightly detonated, and each blasting is 3 rows. | Most of the ore is thrown into the way when it is blasted, and it is discharged by electricity in the way. The ore that has not been thrown into the way is manually cleaned into the way. | It mainly relies on the pillars on both sides of the mine. Reinforce with anchor when local instability |
Large platinum mine | Digging along the long axis of the mine, and then expanding from one end to the other to the width of the mine | Shallow-eye drop mine, eye depth 1.5m, W= 0.8m, W/d= 20, blasthole parallel arrangement | The 7.5kW electric raft is used for transportation, and the 7.5kW electric shovel is used for loading and unloading. | Mainly relying on the pillars on both sides of the mine |
Zhangjiakou Gold Mine Dongkeng 1404m9 block | Dig the road along the long axis of the mine, and then expand the mining to the boundary of the mine | Shallow-eye mine, eye depth 1.6 ~ 1.8m, eye distance 0.8m | In the way, it is transported to the mountain with 5.5kW electric raft, and then transported with 13kW electric shovel. | It is mainly supported by mortar anchors. The length of the bolt is 1.6~1.8m and the density is 0.8~1/m 2 . Partial wood column and wooden shed support |
Zhangjiakou Gold Mine Dongkeng 1357m5 block | First cut the top of the mine and hit the anchor to protect the roof, then push the slope to the working direction | Shallow-eye mine, eye depth 1.8~2m | Electric eel mining, there are 15kW and 28kW, the bucket is 0.2m 3 and 0.3cm 2 respectively. | Anchor rod and metal mesh joint support. Bolt density 1.9 / m 2 , metal mesh network 5 × 5cm 2 and 3 × 3cm 2 |
It can be seen from Table 3 that the room and pillar mining method applied in gold mines is divided into two types: shallow-eye falling mine and medium-deep hole falling mine. When using shallow-eye mining, if the mine thickness is less than 4~5m, single-layer mining is adopted, and when the thickness is more than 4~5m, stratified recovery is adopted. The form of the working face is divided into an upward step, a down step and a squat-shaped working surface. The propulsion mode of the working face is divided into a variety of ways, from the bottom to the bottom, and from the bottom to the top, and along the strike. The quarry is used for transportation and transportation, and individual mines are used for explosive operation.
Roof management application of anchors, irregular pillars and wood column support.
Fourth, the main technical and economic indicators
The main technical and economic indicators for the application of the room-column method in gold mines are shown in Table 4.
Table 4 Main technical and economic indicators of room and pillar mining method
Mine name | Nugget production capacity /t·d -1 | Picking ratio /m·kt -1 | Ore damage Loss rate /% | Ore poor Rate /% | Explosive consumption /m 3 ·t -1 | Pit wood consumption /kg·t -1 | Remarks |
Xiangxi Gold Mine Woxi Mining Area | 70 | 20.5 | 13.8~17.4 | 5~10 | 0.275 | 0.0002 | |
Linghu Gold Mine | 65 | twenty two | 10.9 | 11.9 | 0.462 | Bolt consumption 0.159 roots/t | |
No. 505, No. 1498mII, Shaoguan Gold Mine | 75 | Mine room 18 Pillar 33.34 | 14.5 | 8.35 | 0.48 | Bolt consumption 0.468 roots/t | |
401 No. 402-I Nugget, Shaoguan Gold Mine | 45~50 | 40 | 15.2 | 20.2 | 0.46 | ||
Large platinum mine | 15~20 | 40 | twenty two | 35 | 0.59 | 0.002 | |
Zhangjiakou Gold Mine Dongkeng 1404m9 block | 17 | 5.7 | 0.16~0.48 | 0.0014 | |||
Zhangjiakou Gold Mine Dongkeng 1357m5 block | 50.7 | 18.5 | 27.3 | 1.38 | 0.233 | 0.147 | Mining cost 10.36 yuan / t (1982) |
As can be seen from Table 4, the production capacity of the ore block is mostly 50 to 70 t/d. The production capacity of the ore block is higher than that of the comprehensive method. The reason is that when the room and column method is applied, several mine houses can be arranged in one mine block for simultaneous production. The ore loss rate is mostly 15% to 20%, and the ore depletion rate is 5% to 35%, which varies widely.
V. Review
The room-column method is mainly used in thin and extremely thin ore bodies in gold mines. Therefore, the single-layer mining of shallow-eye mining is mainly used in the mining process. An important trend in the practice and experimental study of gold mine production is the use of bolt guards to maintain operational safety and reduce loss and depletion. For example, the Zhangjiakou gold mine experiment has studied the pole column method, which greatly reduced the ore loss rate, depletion rate and pit wood consumption, and proposed different maintenance methods and structural parameters for different roof stability. Another example is the Linghu Gold Mine, which has been studied and studied. “The mining method along the inclined receding anchor roof protection columnâ€, due to the use of anchor roof protection, and taking reasonable structural parameters and mining sequence, the room and column method is applied to the roof. Under unstable conditions, it has achieved success and has been promoted and applied in this mine. Shaoguan Gold Mine in the No. 505 vein 148mII block tested the "anchor roof pre-controlled throwing blasting room column method", before the mining room mining, the roof was cut open and bolted to ensure the stability of the roof during the mining. In the Zhangjiakou gold mine in the 1357m5 block of Dongkeng, the anchor column and metal mesh were used for the extremely unstable roof, and good results were obtained. In the roof management technology, in addition to the application of various forms of anchors, generally, the use of irregular ore pillars, wood column support and other measures. Due to the uneven distribution of grades in the gold ore bodies, there is a great change. In order to fully recover the resources, the richer ore sections are not discarded, so a feature of the room-column method is applied. In addition, in the mining of thin ore bodies with a thickness of less than 1 m, in order to reduce the depletion rate, the Shaoguan gold mine was tested by the selective mining and mining method, and the ore depletion rate was reduced from 43% in mixed mining to 20.2%. The effect is remarkable. In terms of mining technology, Shaoguan Gold Mine has quite a special feature in the study of the medium-thickness ore body column method. It applies the medium-deep hole mining and throwing blasting technology, which greatly improves the ergonomics and the production capacity of the ore block. The conditions of the mine have reference value. The main disadvantage of the application of the housing in gold mines is the high ore loss rate and depletion rate (15%-20% and 5%-35% respectively), especially when the pillars account for a high proportion of the ore and cannot be fully recovered. The ore loss rate is higher. Therefore, how to further reduce ore loss and depletion is still an important issue in the application and research of the room and pillar method.
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