RU2806387C1 - Method of mining ore bodies - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: invention can be used in the mining of steeply dipping ore bodies of low and medium thickness. The method, which involves the arrangement of rhomboidal-shaped chambers in a checkerboard pattern on adjacent floors, includes the excavation of loading orts, delivery and trench drifts, drilling sublevel drifts, cut-out raise, formation of the outlet trench to the full thickness of the ore body by breaking wells, formation of a slot by breaking wells on the raise. The breaking of the chamber is carried out with the delivery of ore by the force of explosion and gravity into the outlet trench. The ore is partially stored to protect the bottom from direct impacts from pieces of ore. The inclination of the lower faces of the chamber is increased by doubling the number of outlet workings to the angle of collapse of the partially stored ore. To optimize drilling and blasting operations, drilling drifts run on two sublevels obliquely to the horizon. In order to protect the inclined part of an extended ceiling from repeated seismic effects of explosions and to level the edges of the chamber, condensed fans of wells are drilled along these edges preventively and smooth-wall blasting is carried out. A temporary support pillar is formed in the center of the chamber with adjustable parameters corresponding to the stability of the hanging wall rocks. The rear sight is collapsed into the outlet trench after the chamber has been worked out.

EFFECT: increase in the productivity and intensity of excavation and ore extraction rates, as well as the stability of the hanging wall and bottom.

1 cl, 3 dwg

Description

The invention relates to the mining industry and can be used in the mining of steeply dipping ore bodies of low and medium thickness.

There is a known method for mining steeply dipping ore bodies using a system with the delivery of ore by explosion, including the sinking of a loading ore, outlet funnels, sublevel drilling drifts, a cut-off riser, the formation of a cutting slot, the breaking of a chamber in two stages, leaving a temporary ledge that forms an additional ore receiving tank to the funnels and the delivery of ore explosion [A.S. No. 199064, MPK E21s, Cl. 5 s. 7, 13. VII. 1967, bulletin. No. 15].

The disadvantage of this method is the leaving of a temporary intra-chamber pillar, the subsequent collapse of which is associated with increased losses and dilution.

The closest to the invention is a method for mining steeply dipping ore bodies of low and medium thickness with rhomboidal-shaped chambers located in a checkerboard pattern on adjacent horizons, with breaking from a sublevel drift, delivery of ore by force of explosion and gravity along the inclined lower edges of the chamber and release through one funnel [A .WITH. No. 609433, (51) M. Cl. ² E21s 41/06, 12/15/79, bulletin. 46].

Disadvantages of the prototype method:

- low productivity of bottom preparation with excavation of the pipe and funnel;

- low intensity of the cleaning excavation, since it is limited by the output through a single funnel located in the corner part of the chamber;

- vulnerability of the outlet from intense wear due to the large volume of ore (up to 70-80 thousand tons) discharged through one funnel, and the high risk of the chamber becoming out of working order;

- the angle of inclination of the lower edges of the camera in Fig. is not steep enough. 2 it is equal to 45°) for the free flow of partially stored (and used as an ore cushion, which is necessary to protect the bottom workings from direct impacts with large pieces of ore;

- an obtuse angle where the wells meet the contour of the chamber, which is associated with its ridged relief after breaking, causing increased losses of ore during breaking and its retention on the soil of the chamber;

- a large area of exposure of the hanging wall rocks, covering two floors, carries the risk of large-scale uncontrolled collapse of the chamber;

- repeated seismic load from explosions on the extended inclined part of the ceiling (pillar along the upper edge of the chamber) in combination with rock pressure weakens it and requires an increase in thickness;

- transfer of ore by explosion through the funnel and settling of enriched ore fines on the edges of the chamber;

- the formation of lower and upper undercuts is unsafe, costly and ineffective due to their local area;

- lateral outflow of ore from the chute onto loading port 3 (Fig. 2) makes it difficult to fully use the power of the LHD, designed for end loading;

- recovery of ~50% of reserves by downward wells reduces the efficiency of extraction;

- the greater depth of the wells in fans in the middle of the chamber, commensurate with the height of the floor, leads to overdrilling the total length of the wells, is more difficult to control the design direction, and leads to an increase in the yield of oversized items;

- low rates of ore recovery when mining the superstructure pillar and ceiling in the second stage;

- in conditions of increased risk of mining production, the release of ore from a chamber (especially large sizes) only through one opening contradicts the requirements of technical operation regarding the need to reserve the throughput of the narrowest technological link;

- sharply (multiple) different volumes of reserves in the layers mined at different stages of chamber mining make it difficult to synchronize ore flows during mining and release;

- high resource intensity, measured by the amount of deposit reserves occupied by mining operations, per 1 ton of production capacity of the mine;

- low level of safety in mining operations, associated with a significant probability of emergency situations threatening the failure to fulfill the mine’s production program.

Disclosure of the invention. The invention is characterized by a multi-purpose transformation of technology due to the multiplicity and variety of disadvantages. It is aimed at increasing the productivity and intensity of mining, ore recovery rates, eliminating the risk of collapse of hanging wall rocks, and increasing the stability of the bottom workings.

The essence of the invention is revealed by a combination of the following actions and techniques.

The claimed method, which provides for a staggered arrangement of rhomboidal-shaped chambers on adjacent floors, includes driving loading orts, delivery and trench drifts, cutting uplift, forming an outlet trench by breaking wells for the entire thickness of the ore body, forming a cutting slot by breaking wells into uplift. The breaking of the chamber is carried out with the delivery of ore by the force of explosion and gravity with partial magazineing of the ore, which is necessary to protect the bottom from direct impacts from pieces of ore.

The difference between the method is that by doubling the number of outlet workings, the slope of the lower faces of the chamber is increased to the angle of collapse of the partially stored ore. This solution simultaneously provides the principle of 2-fold redundancy of the capacity of a critically “narrow” technology link. To optimize drilling and blasting operations, drilling drifts run on two sublevels obliquely to the horizon. In order to protect the inclined part of an extended ceiling from repeated seismic effects of explosions and to level the edges of the chamber, condensed fans of wells are drilled along these edges preventively and smooth-wall blasting is carried out. A temporary support pillar is formed in the center of the chamber with adjustable parameters corresponding to the stability of the hanging wall rocks. After the chamber has been worked out, the temporary rear sight is collapsed into the outlet trench.

The positive effect of the invention is manifested in a set of indicators: increasing the productivity and intensity of excavation, the completeness and quality of ore extraction, reducing the risk of collapse of hanging wall rocks, increasing the structural strength of the bottom, and the reliability of the production program.

The essence of the invention is illustrated by the drawing, where in FIG. 1 shows the general technological diagram of the method and all technical results. In fig. Figure 2 shows the formation of a temporary support pillar in a transverse section. Fig. 3 shows a diagram of drilling a condensed fan of wells for smooth-wall blasting.

The drawing shows: delivery road 1, loading holes 2, trench road 3, reinforced outlet face 4, ceiling 5, artificial “crack” 6 formed by smooth-wall blasting, condensed fan of wells 7 for smooth-wall blasting, drilling niche 8 for drilling condensed fans of wells, outlet trench 9, angle of inclination of the lower edges of the chamber equal to the angle of collapse β of partially stored ore, inclined sublevel drilling workings 10, angle of meeting α of the fan of production wells with the design contour of the chamber, temporary support pillar 11, cut-off rising 12, bifurcation 13 of cut-off rising, ventilation-passage joint 14, drilling stope 15 for collapsing the temporary support pillar, collapsed rock 16.

Implementation of the invention. The invention is focused on the use of high-performance mining equipment, so the trench method of preparing the bottom was chosen instead of sinking a hole and a funnel according to the prototype. Preparatory work in the chamber includes driving the delivery drift 1, the loading gates 2 and the trench drift 3, which runs at the level of the roof of the loading gates, which eliminates the need for tunneling. In the conditions of mining production, which is characterized by high risk, operating rules require reserving the throughput of the most “narrow” technological links. In the prototype method, the critical “narrow” link is the release of ore from the chamber, which involves the use of only one funnel for release. The invention provides for a 100 percent reserve of production productivity. But even with a 2-fold increase in the number of outlet workings in the chamber, the outlet hole (especially the face) remains the most vulnerable place in the bottom due to the large volume of ore released through one working. The most effective means of achieving production continuity is maintenance-free operation of the bottom, ensuring the maintenance of workings in operating mode throughout the entire service life. For this purpose, before the formation of the outlet trench, the connection of the loading ort with the trench drift is preventively secured with cable rods, and especially reliably with reinforcement - face 4. This measure avoids repair work in the bottom during the formation of the trench and the excavation. Another weak link of the prototype method is the repeated seismic impact of blasting on the extended inclined part of the ceiling 5. To avoid this phenomenon, it is proposed to form an artificial “crack” 6 separating the future ceiling from the mass being broken off. In the invention, such a “crack” is created by advanced smooth-wall blasting of a condensed fan of wells 7 along the contour of the chamber. This technological solution also performs another important function. The artificial “crack” serves as a separation plane along which the ore is torn off when breaking the chamber and thereby smoothes the edge of the chamber, ensuring the unimpeded delivery of ore by the force of explosion and gravity. The individual plane, as well as the frontal reinforcement, is created preventively. Drilling of a condensed fan of wells for smooth-wall blasting is carried out from a drilling niche 8 formed from a trench drift. The outlet trench 9 is formed by breaking the wells after the formation of an artificial “crack”. The potential of the method is determined by the completeness of ore delivery along inclined faces into the outlet trench. The prototype method does not meet this requirement, since the accepted angle of inclination of the lower edges of 45° and their ridged relief lead to the accumulation of part of the broken ore on the soil of the chamber. It aggravates the retention of ore and its compaction in the layer left on the bottom, which is necessary to protect the workings from direct impacts from pieces of ore. In the invention, the angle of inclination of the lower faces of the chamber is increased to the collapse angle of partially stored ore β, which eliminates the retention of ore on the inclined faces. The complete flow of ore from the chambers is also facilitated by the smooth surface of the lower edges created by smooth-wall blasting. This factor also helps to increase the extraction of ore from the ceiling, which is collapsed in the second place.

The principle of production flow requires synchronization and equal productivity of adjacent technological processes, in this case breaking and tapping. In the prototype method, the volume of drilling with one drilling rig in the middle of the chamber is several times greater than the volume of drilling on the flanks of the chamber. Under such conditions, it is difficult to ensure the same breaking performance at different stages of chamber development, corresponding to the release performance. The invention provides for doubling the number of drillings 10 in the chamber by drilling them on two sublevels obliquely to the horizon. This solution not only simplifies the regulation of mining productivity, but also eliminates over-drilling of the total length of the holes by reducing the depth of the holes in the fans, which helps to increase the ore yield from 1 m of holes. In addition, with a shallower depth of wells, it is easier to control their design direction, which makes it possible to reduce the tightening of chambers during breaking and the output of oversized items.

The performance of chamber-type systems is determined by the reliability of controlling the hanging wall outcrop area. The prototype method is not endowed with this function, since it is designed for a constant and prohibitively large area of exposure of the hanging wall, corresponding to the combined height of two floors. Moreover, the outcrop area is not tied to the actual stability of the rocks of the chamber being mined, but is strictly specified by the parameters of the chamber of the upper floor. The invention is equipped with a flexible system for controlling the area of exposure of hanging wall rocks. The scheme for cutting work in the chamber provides for the possibility of leaving a temporary support pillar 11 in the center of the chamber. Moreover, depending on the stability of the rocks on the hanging side of the chamber being mined, the height (along the dip) of the pillar is adjusted. The physical and mechanical properties of the rocks of the hanging wall of the mined chamber are established in advance during the process of drilling the cut-off riser 12. To allow for optimal placement and formation of the supporting pillar, the cut-off riser bifurcates in the middle of the chamber 13. The riser is connected to the overlying horizon by a ventilation-pass joint 14. After mining the chamber, a temporary the supporting pillar is collapsed into the outlet trench from the drill stope 15. The ceiling pillar 5, together with the near-gate pillar, is collapsed last after mining adjacent chambers. The invention is distinguished by a complex innovative structure, multi-vector optimization transformation of technology and a high level of creativity.

Claims (1)

A method for mining steeply dipping ore bodies of low and medium thickness with rhomboidal-shaped chambers located in a checkerboard pattern on adjacent floors, including the sinking of loading ores, delivery and trench drifts, drilling sublevel drifts, cut-off risers, the formation of an outlet trench by breaking wells for the entire thickness of the ore body, formation of a cutting slot by breaking wells into a riser, drilling fans of wells, breaking a chamber with the delivery of ore by force of explosion and gravity into the outlet trench, characterized in that by doubling the number of outlet workings, the slope of the lower edges of the chamber is increased to the collapse angle of partially stored ore, to optimize drilling and blasting operations drilling drifts run on two sublevels obliquely to the horizon, to protect the inclined part of the extended ceiling from the seismic effects of explosions and to level the edges of the chamber, condensed fans of wells are drilled preventively along these edges and smooth-wall blasting is carried out, a temporary support pillar with adjustable parameters corresponding to stability is formed in the center of the chamber hanging wall rocks.