Improvement of Mining Technology in Shallow Hole Retaining Method in Shanggong Gold Mine

Palace is one of the gold mine in Luoyang Yu-kun Mine Mining Ltd. subsidiary, located in Luoyang city Luoning County, Western Hills Township. The mining area is located in the southern margin of the North China Platform and the Xiong'er Mountain Long Section. The exposed stratum of the mining area is monoclinic and spreads to near EW. There are 9 fault-bearing altered rock belts in the mining area. Among them, the F1-I gold-bearing altered rock belt has the largest scale and the best gold content. The F1-I gold-bearing altered rock belt has an elevation of 142~1197m, a strike length of 850m, an ore body trend of 317°, an inclination of 58°-60°, an average thickness of 1.70m, and a thickness variation coefficient of 126%. type. The gold-bearing structural altered rock belt has an average geological grade of 6.11 g/t and an ore body grade variation coefficient of 83%, and is a homogeneous ore body with a useful component distribution. The shape of the ore body is irregular vein shape and thin plate shape. It is vein-like and pod-shaped on the section, and has partial branching and compounding phenomenon. The surrounding rock of the top and bottom of the ore body is dominated by andesite and altered rocks, and a small part of the area is fractured rock, breccia and breccia. The engineering geological conditions are more complex. The water-filled water source of the ore deposit is mainly atmospheric precipitation, the water-filling channel is a fault structural zone, and the hydrogeological conditions are simple types.
In order to further improve the mine's mining efficiency, this study improved the use of the bottom-hole shallow hole retention method [1-5] for the mine.
1 Overview of the preliminary development project of the mining area
The Shanggong Gold Mine has six parallel veins controlled by the F1 structure, which are arranged in order from south to north. The distribution is shown in Figure 1. In order to effectively explore all the veins, after the prospecting and veining firstly explores the F1-1 vein, the exploration and penetrating veins continue to explore other veins. Therefore, when the roadway is transported, the extra-vehicle flat roadway and the pulse-piercing form are used. The outer surface of the F1-1 ore body is arranged around 7m, and a prospecting and penetrating vein is arranged every 50m for prospecting until the ore bodies are exposed. When the mining is carried out, the veins along the veins are drilled.

Bottom column shallow hole retention method
2.1 In-pulse sump retention mining process
(1) Structural parameters. The mine is arranged along the ore body, with a length of about 50m, a stage height of 40m, and a width of the ore body thickness. The top of the mine is 4m thick, the width of the column is 3m, the height of the bottom column is 6~7m, the spacing between the links is 6m, and the spacing of the funnel is 7m (Fig. 2).
(2) Cutting work. In the gondola along the vein transport roadway, every 50m upwards into the veined patio, and through the return air alley. Dig 3m communication roads to the mines on both sides every 6m in the vertical direction of the patio. The cutting lane is excavated at a height of 4m from the roof of the roadway along the roadway. The funnel neck is drilled every 7m in the roadway along the vein transportation lane, and the funnel is formed on the basis of the bottoming tunnel. Main roadway section specifications: 2.0m×2.0m along the roadway of the roadway, 1.8m×1.5m in the pulsed courtyard, 1.8m×1.8m in the connecting road, 1.8m×1.8m in the bottom roadway The funnel is 1.5m x 1.5m.

(3) Mining work. The mining back is carried out from the bottom to the top. The YT-28 rock drill is used to cut the upward or inclined blasthole. The inclination angle is about 60° and the blasthole depth is 2.2m. According to the actual thickness of the ore body, the shape of the ore is adopted. "One" type cloth eye, manual charge, segmented differential blasting.

After the blasting is ventilated, the ore that has collapsed is discharged through the funnel by about 1/3 each time. After partial ore mining, inspect the roof and the two gangs, handle the pumice to ensure safety, level the site, and prepare for the next cycle until the end of the mining, and then release a large amount of ore.
2.2 There is a problem
(1) The loss of mineral loss caused by the removal of the bottom column and the inter-column is too large. Due to the high geological grade of the F1-I vein, the loss of this part of the ore will directly lead to the loss of certain economic benefits.
(2) The ore depletion rate is relatively large, mainly due to the fact that the relevant technical parameters are not effectively controlled during the rock drilling process, resulting in the incorporation of a large amount of waste rock.
(3) When the artificial funnel is used for ore mining, the large block is easy to block the funnel mouth, and the large block in the secondary blasting funnel easily breaks the wooden funnel and affects the mining.
(4) The construction of the bottom leakage is relatively complicated and the tunneling efficiency is low, and the funnel neck cannot be digged in the unstable area of ​​the local vein transportation lane. In addition, the funnel is erected in the vein transportation lane, and the workers are safe to mine and transport. Hidden dangers.
3 mining process improvement
3.1 improvement plan
(1) Improve the structure of the ore block. The structural parameters and arrangement of the ore block are basically unchanged from the original plan. The difference is that the bottomless column structure (extraction wear) is used for mining. The upper and lower sides of the vein are changed from the pulsed inner patio to the outer pulsed patio and the original stope is along the vein. The transport lane specification is slightly expanded and used as a mining cutting tunnel (Fig. 3).

(2) Improve the cutting project. In combination with the layout of the transportation lanes in the middle stage of the preliminary development project, when using the extra-pulse sill-free shallow hole retention method, only the original two adjacent prospecting veins should be placed, and a corner should be arranged every 7m near the lower part of the stope. The ore-penetrating vein can reach the ore body, and each stope is arranged with 6 to 7 ore-penetrating veins, which are 5 to 7 m long. An extra-pulse patio is arranged at 5 to 7 m from the lower side of the stop for pedestrian ventilation and material transportation, while ensuring that the exit has two safety exits. In the vertical direction of the patio, a contact line perpendicular to the ore body orientation is arranged every 6m until it reaches the ore body, and then the mine body is drilled along the ore body to the left and right sides of the mine to drill a 3m wide mine contact road for subsequent recovery. When the stope is connected with the contact road, the contact road on the patio adopts a staggered arrangement, which is conducive to mining management, mining operations and reducing the amount of cutting work.
(3) Improvement of mining technology. 1 Restrict the length of the drill rod, it is required to use the drill rod with the length less than 1.8m to ensure that the hole depth of the rock drilling hole is about 1.5m, to prevent the excessively long drill rod from damaging the surrounding rock of the upper and lower plates during the construction process, affecting the depletion Rate and bulk rate; 2 strictly control the distance between the side hole and the surrounding rock is more than 0.3m. When the surrounding rock of the upper and lower plates is broken, the side hole can be appropriately arranged to the middle; 3 when performing the support work in the stope, to prevent Partial upper and lower discs surrounding the rock fall lead to excessive depletion rate, take the retention point column or use the horizontal support and backboard support, the point column is preferred in the ore rock is broken or the ore grade is not high, the mine line In the narrower area, the support cross bracing should be buried in the ore for more than 0.3m before the shot is fired to prevent it from being blown off during blasting. 4 After the ore is blasted and ventilated, the Z-20W electric rock loader is used. Mineralization is carried out in the veins.
3.2 Implementation effect
According to the engineering practice of the new stope, the main economic and technical indicators before and after the improvement of the mining process are shown in Table 1. It can be seen from Table 1 that: 1 The use of the extra-nozzle bottomless column can not only recover the column and the bottom column at one time, so that the recovery rate is obviously improved, and the cutting ratio is reduced slightly; 2 by limiting the length of the rod and taking support Measures, although the mining efficiency has been reduced, but the depletion rate has been greatly reduced; 3 by using the ore-penetrating rock-filled rock machine to mine, greatly improving the mining efficiency, making the production capacity of the ore block at least one Times.

4 Conclusion
(1) The use of short drill rods and support in the stope can effectively control the bulk rate and depletion rate of ore.

(2) The use of the bottomless column structure to install the rock loader, although the excavation cost of some ore-penetrating veins is increased, the bottom column ore can be recovered at one time, which greatly improves the mining efficiency, reduces the labor intensity of the workers, and improves the labor intensity. The safety factor of the miners.

(3) The layout of the pulsed patio is adopted. Although some excavation works are added, the columns on both sides of the mine can be completely recovered, which reduces the ore loss rate and ensures pedestrian safety more reliably and reliably.
(4) The patio contact road adopts a staggered layout to facilitate mining operations and mining management. Compared with the parallel arrangement, the amount of cutting and cutting works is reduced.
references
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