RU2382200C1 - Opencast with two closely located ore bodies development method - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: method can be used for minerals mining operations at vertical incidence limited with two ore bodies. Execute both ore bodies simultaneous production, one - by ore body contact with host rocks, other one - leaving ore pillars by the cast sides. After the second cast development till an intermediate bottom, go through inclined core entering turning platform and execute transport connection to the transfer platform during pillar development period. Step by step create from the turning platform a new steeply inclined transport exit with a longitudinal slope 20%-25% along the open cast edges, closing an old one, throw opened rock into intermediate bottom and transport, in into to the cast inside stock, already developed until designed depth, after the second cast completion till its designed depth move part of a capping there, creating a pad for the both casts.

EFFECT: mineral development efficiency and outcome increase due to decrease of capping volume, its transportation arm during the following cast deeping and its bottom formation then transferring to underground mining.

5 cl, 1 ex, 1 tbl, 3 dwg

Description

The invention relates to the mining industry and can be used for open-pit mining of mineral deposits with a vertical drop of ore bodies limited in plan, in particular kimberlite pipes with the preparation of the bottom of the quarry for transition to underground mining.

There is a method of reconstruction of a quarry with two nearby ore bodies, including at the intermediate stage the separation of the sides of the general quarry, with the detuning of new sides formed by built-up ledges with parameters acceptable by their stability, separated by safety burs, the formation of transport exits for two-lane movement of heavy dump trucks, at the stage completion of the formation of the headland and the ring traffic exits of the oncoming direction with single-lane traffic dump truck in, abutting on the pivot platform, with detuning pit walls in places steep fall orebody ledges convexly broken profile height of 60-180 m, the factory shipping ore and gangue - external dumps. At the stage of completion, in addition to the headland, an unloading platform is formed, below which a steeply inclined ramp with a longitudinal slope of 300-360 ppm is constructed between the quarries, ore bodies are mined alternately by steeply inclined stub ramps with a width that provides two-way movement of tracked dump trucks and transported the first quarry to the transshipment site, ore is loaded into dump trucks, the empty rock is stored on board the second quarry, and after full The work of the second quarry waste rock of the first and second quarries is placed in the worked out space of the first quarry and inclined adits pass on the base of the rock pillar to bypass drainage water from one quarry to another (RF Patent No. 2314420, Е21С 41/26, published on January 10, 2008 )

The disadvantage of the above technical solution is the limited scope of its application. Limiting factors are the transverse dimensions of the ore bodies and the maximum possible longitudinal slope of the ramps, which leads to a small amount of temporary preservation on board the ore pit and overburden, as well as the impossibility of increasing the depth of open cast mining if necessary. In addition, the introduction of transport congresses on the pedigree pillar necessitates the use of super-steep slopes and the use of low-productivity tracked dump trucks with reloading to heavy dump trucks. The above factors worsen economic indicators and reduce the efficiency of open pit mining.

The closest in technical essence and the achieved result is a method of reconstruction of a quarry with two closely located ore bodies, including at the intermediate stage the separation of the sides of the general quarry, with the detuning of new sides formed by built-in ledges with parameters acceptable by their stability, separated by safety burs, and the formation of transport exits for two-lane movement of heavy dump trucks. At the stage of refinement of ore bodies, a headland and ring transport exits of the opposite direction with single-lane traffic of dump trucks that are joined at the headland are formed, the sides of the quarry are rebuilt in places of steep fall of the ore body with ultra-high ledges, the ore is transported to the factory, and waste rock to an external dump. Transport communications place one of the ore bodies in the part of the quarry field, refine them to the design depth with leaving ore pillars, form a discharge ramp in the worked out space until they adjoin the ramp on the limiting contour of the quarry, and refine the ore pillars in layers, by paying off transport exits, rebuilt by the ore body (RF Patent 2230192, Е21С 41/26, publ. 10.06.04, Bull. No. 16).

The disadvantage of this method is the need to remove the entire volume of overburden from the quarry, followed by the formation in the worked out space of a loose exit, which requires significant costs and time. To exclude a break in ore mining during the construction of the dumping congress, it is necessary to accumulate ore at an expendable warehouse in volumes sufficient to supply the factory with ore, or to reduce processing volumes. All this leads to a large unevenness of mining operations and an increase in the need for mining transportation equipment, and with a decrease in ore processing volumes, a decrease in marketable products. In addition, the completion of ore pillars will be carried out in difficult conditions on a limited spacing strip in a layered way without forming new transport communications on board the quarry and transporting ore through the dump exit, which leads to a large mileage of dump trucks. In addition, this method excludes the possibility, if necessary, of increasing the depth of the quarry, which is limited by the placement in the worked-out space of a loose exit. All this reduces the efficiency of mining operations, worsens economic performance and does not provide the required configuration of the bottom of the quarry for the transition to underground mining.

The technical result of the invention is to increase the efficiency and completeness of the extraction of minerals by reducing the volume of overburden, the shoulder of its rollback during the further deepening of the quarry and the formation of its bottom for the transition to underground mining.

This goal is achieved by the fact that in the method of finalizing a quarry with two nearby ore bodies, including the construction of ring transport exits of the oncoming direction with single-lane movement of dump trucks that are joined at reversal areas, and an unloading platform, the alignment of the quarry sides in places of a steep fall of the ore body with convex-broken ledges profile, separated by safety berm of the required width, the formation in the part of the quarry field along one of the ore bodies of the spiral transport of the congress, with a width that provides two-way traffic, ore mining simultaneously for both ore bodies: one at a time — at the contact of the ore body with the host rocks, at the other — leaving ore pillars on the sides of the quarry, while finalizing the ore pillars, the stage-by-stage formation of a new transport congress with the redemption of the old congress, transportation of ore to the factory, and overburden to the external dump, after the completion of the second quarry, an inclined shaft passes to the intermediate bottom with access to the headland the flap, when finalizing the ore pillars, transport ramps are steeply inclined, aboard overburden, dump overburden to the intermediate bottom and transported to the internal dump of the quarry, which has already been worked out to the design depth, and after the second quarry is refined to the design depth, part of the overburden is moved there to create the rock pillows in both quarries.

Moreover, the formation of steeply inclined transport exits is carried out with a longitudinal slope of up to 20-25%.

And the ore is transported to the factory by articulated dump trucks to the overlooking transshipment platform, where they are loaded into heavy-duty dump trucks and transported aboard the quarry.

For the period of completion of the pillar transport communication to the headland is carried out through an inclined shaft.

Transportation of the overburden to the bottom of the first quarry is carried out by underground wheeled dump trucks delivered to the bottom of the quarry through an inclined shaft.

The construction of an inclined shaft with access to the intermediate bottom of the second (mined) open pit allows for the transport connection of the intermediate bottom of the mined open pit with a headland for the period of ore pillars spacing. This makes it possible to deliver mining equipment (underground dump trucks, bulldozers, caterpillar dump trucks, drilling rigs) and people for re-transportation of overburden thrown down into the spent space of the first quarry, and, if necessary, in ore that has been dumped and delivered through the inclined shaft to the headland, where it is loaded onto heavy trucks and transported along a single-lane exit onto the quarry. The presence of transport communications also allows you to service the work of career drainage. Reducing the distance of transportation of overburden, maintaining the operation of mine drainage ensure the completeness of ore extraction, the efficiency and safety of mining.

The formation of new pillars at the ore pavement from the headland with a steep slope along the side of the mined quarry allows the formation of a new transport link between the overlying and underlying headlands on a limited section of the side, transporting the ore mined when the pillars are separated to a transshipment platform and then loading it on heavy trucks, on board the quarry, which increases the completeness of excavation and the efficiency of work.

Moving part of the overburden of the second quarry, stored in the mined space of the first quarry, allows you to form a rock pillow along both ore bodies, to conduct subsequent underground mining of quarry reserves by systems with collapse with a minimum thickness of the rock pillow, and stability of the lower ledges of the second quarry during refinement. This increases the efficiency of the method.

The formation of steeply inclined transport ramps with a slope of 20-25% reduces the length of the ramps and reduces the size of the carried pillar, which can significantly reduce the volume of overburden in the whole and increase the efficiency of the refinement method.

The use of articulated dump trucks for transporting the rock mass to the reloading platform allows to reduce the size of the pillar and the overburden volume, respectively, to reduce the number of dump trucks, which allows to increase the depth of the quarry and the completeness of the extraction of minerals, to form the bottom of the quarry for going to underground mining, to increase the efficiency of the refinement method in whole.

The method is illustrated by drawings,

where in Fig.1 shows the position of mining at the end of the mining of the first quarry in plan and section along AA;

figure 2 shows the position of mining at the final stage of finalization of the second quarry of the eastern ore body (VRT) in plan and section along AA;

figure 3 is a section along aa in figure 2; the position of the bottom of the quarry at the time of transition to underground mining,

where 1 is the quarry on the western ore body (ZRT)

2 - open pit on the eastern ore body (ART)

3 - ring transport exits of the oncoming direction with single-lane traffic;

4 - a headland on which the ring transport exits of the opposite direction are joined at a depth of 490 m;

5 - temporary rear sight of ART;

6 - temporary spiral two-way exits;

7 - platform under the portal of the inclined trunk;

8 - an inclined trunk;

9 - a headland of ring two-way oncoming exits at a depth of 355 m;

10 - steeply inclined transport exit on board the ART;

11 - transshipment platform at a depth of 250 m;

12 - internal overburden dump on ZRT;

13 - pedigree pillow for ZRT and VRT.

Concrete example

Field tr. “Udachnaya” is represented by two steeply falling independent ore bodies 1 and 2 - western and eastern, separated by a rock lintel. Testing is carried out in stages along the depth of the general quarry. The projected pit depth was taken equal to 610 m, however, to ensure a smooth transition to underground mining of quarry reserves and the formation of a rock pillow, it was necessary to increase the pit depth by another 30 m, i.e., the pit depth was increased to 640 m.

In the process of mining the rock mass in the contours of the initial stages of development of the field, the depth of the side of the Udachny open pit is formed by built-up ledges at an angle of inclination of slopes of 60-75 °, separated by safety burs of the required width and two-lane transport ramps of the opposite direction to a depth of 400 m with turning and reloading sites. The width of the ramps to a depth of 400 m provides two-way movement of heavy vehicles. The preparation of rocks for excavation is carried out by a blasting method, then the rock mass is shipped by excavators to dump trucks and transported to a concentration plant and to external dumps.

In the depth range from 400 to 490 m, the open pit is opened by single-lane ramps of the oncoming direction 3, which are joined at a depth of 490 m with a turning platform 4, on which a pilot industrial underground section (OPPU) with tunneling of two sub-parallel tunnels is built (in Fig. 1 , 2 and no.).

The sides of the quarry are formed by ledges of a convex-broken profile with a height of 45 m. And the upper part of the ledge with a height of 30 m is formed at an angle of 75 °, the lower part with a height of 15 m is formed at an angle of 90 °. Overburden is exported to an external dump on board the initial quarry, and ore is transported to a concentration plant.

Further, the autopsy is performed on the eastern ore body (VRT) 2 with the ore pillars being left 5 by a temporary two-lane spiral exit 6. At the same time, about 8 million tons of ore and 3.5 million m ³ overburden are temporarily conserved on board the VRT quarry. They begin to work out the western ore body (ZRT) 1 to the level of 640 m. At the same time, the VRT 2 is being worked out to an intermediate mark of 610 m.

By the time of completion of opencast mine 1 at the ZRT to the design elevation (640 m), an inclined shaft 8 passes from the site 7 on the northern side at a depth of 610 m into the annulus with access to the overlying headland 4 at a depth of 490 m, which serves as an emergency exit and transport exit (OPPU site).

The next stage begins with the separation of the temporary pillar 5. The separation height of the temporary pillar 5 (Hp) is determined by the dimensions in plan between the headland on the northeast side at a depth of 355 m, the docking on the headland at a depth of 490 m, the maximum permissible longitudinal slope of the transport exit 20 % and is determined by the formula

Нр = ГП × Iп, m,

where Hp is the separation height, m;

GP - dimensions in plan between two adjacent sites, m;

Ip - the maximum longitudinal slope of the transport exit,%.

With the dimensions in the plan between adjacent platforms equal to 715 m and a longitudinal slope of 20%, the separation height will be 715 × 0.2 = 143 m. From the headland 2, the steep ramp 7 will start at a depth of 150 m, therefore, the total height of the side separation will be 293 m

To do this, a new opening system is formed from turnaround 9 at a depth of 355 m by two-lane steep ramps 10 with access to turnaround 4 at a depth of 490 m. Below this platform 4, the opening direction changes to the opposite and on the eastern side of open pit 2, steep ramp 10 drops to a depth of 640 m. Articulated dump trucks with a carrying capacity of 38 tons are used for ore transportation.

The development of a temporary pillar of 5 ART. In this case, the overburden is dumped to the bottom of open pit 2, and the ore is transported by articulated dump trucks to the loading dock 11 at a depth of 250 m, where it is loaded onto heavy-duty dump trucks and transported to the factory.

The sides of the quarry 2 of the ART are formed by ledges of a convex-broken profile with a height of 45 m. In this case, the upper part of the ledge with a height of 30 m is formed at an angle of 75 °, the lower part with a height of 15 m is formed at an angle of 90 °. Overburden is discharged into the lower contour of open pit 2, where it is loaded onto underground dump trucks and transported along an inclined shaft 8 to the mined space of open pit 1 and stored in an internal dump 12 of the ZRT. Ore when the temporary pillar 5 is separated, the VRT is loaded onto articulated dump trucks with a 6 × 6 wheel arrangement, which ensures their operation on longitudinal slopes up to 20-25%, and is transported along steep ramps 10 and further along existing ramps to the loading dock 11, loaded onto heavy trucks and transported on board the quarry, to the processing plant.

After refinement of the ore pillar of VRT to design elevations, part of the overburden is moved from the western ore body to the eastern one, having built a rock pillow over both ore bodies.

The table illustrates the cost-effectiveness when using the proposed method of mining in comparison with the use of traditional methods using dumping exits.

Table Option ORE PRODUCTION, MILLION TONS Overburden volume, mln.m ³ Volume of transport work, mln.tkm Mining period, years Traditional 12.5 15.0 500.0 5 The proposed method 12.5 3.5 150.0 5

The proposed method allows to reduce the volume of exported (transported) overburden in the quarry contour by 11.5 mln.m ³ , store overburden into the quarry mined space in the amount of 3.5 mln.m ³ , simultaneously forming a rock pillow at the bottom of the quarry, and reduce the amount of transport work by 350.0 million .km, which gives savings of 2.2 billion rubles. In addition, the loading of the lower horizons of the quarry provides greater safety of mining operations by increasing the local stability of the ledges during the transition period from open to underground mining.

Claims (5)

1. A method of refining a quarry with two nearby ore bodies, including the construction of ring traffic exits of the oncoming direction with single-lane movement of dump trucks that are joined at turning sites, and a transshipment platform, detachment of the sides of the quarry in places of steep fall of the ore body with ledges of a convex-broken profile, separated by safety bores the necessary width, the formation of a part of the quarry field, one of the ore bodies, a spiral transport exit, a width that provides two third-party traffic of vehicles, ore mining simultaneously at both ore bodies, one at a time - at the contact of the ore body with the host rocks, at the other - leaving ore pillars on the sides of the quarry, while finalizing the pillars, stage-by-stage formation of new transport exits from the headland with repayment of old ones, transportation ore to the factory, and overburden to the external dump, characterized in that after the completion of the second quarry, an inclined shaft passes to the intermediate bottom with access to the headland, while the ore targets are being finalized Cove transport conventions form steeply inclined, on the side executed by quarry waste rock dumped on the intermediate bottom and transported to the inner blade career already spent to TD, and after completion of the second pit to the design depth is moved to a part of the overburden to create a rock cushion in both pits. 2. The method according to claim 1, characterized in that the formation of steeply inclined transport exits is carried out with a longitudinal slope of up to 20-25%. 3. The method according to claim 1, characterized in that the ore is transported to the factory by articulated dump trucks to the loading dock, where they are loaded into heavy dump trucks and transported aboard the quarry. 4. The method according to claim 1 or 3, characterized in that for the period of completion of the pillar transport communication to the transshipment site is carried out through an inclined shaft. 5. The method according to claim 1, characterized in that the transportation of the overburden to the bottom of the first quarry is carried out by underground wheeled dump trucks delivered through an inclined shaft.

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