RU2278261C1 - Method of combined open-cut and underground steeply pitching deposit development - Google Patents

Abstract

FIELD: mining, particularly to develop mineral deposits formed by permafrost rock and column-shaped ore bodies.

SUBSTANCE: method involves cutting ore body by open-cut mining up to design mark reaching and by open-cut and underground mining up to underground mining mark reaching. During open-cut mining ore body is exposed by inner and outer haulage bench system. During open-cut mining ore is cut by underground excavations in combination with haulage benches. Open-cut works during open-cut mining are carried out with lag interval in vertical direction from underground work equal to not less than working ledge height. Ore located in central ore body part is cut in layers in several steps by blasting down-holes. Ore located in formation-screened ore body part is cut by ascending ring bores drilled from underground excavations. To perform open-cut and underground development recovering excavation is formed in formation-screened ore body part in working pit zone by blasting ring bores drilled from underground excavations. The recovering excavation is expanded in proportion to opened mine work descending by blasting vertical wells at each working step so that subdrilling depth is not less than 1/3 of working step height.

EFFECT: increased efficiency of mine works during ore body cutting below design pit bottom mark.

1 tbl, 11 dwg

Description

The invention relates to the mining industry and can be used to develop mineral deposits from permafrost rocks and ores of predominantly tube-shaped and pillar-shaped forms.

The complex open-underground mining method developed by the IPKON Institute is known, which consists in developing the field in depth in three tiers, while the field is developed by the open method to the design mark for open-cast mining - N ₀ ; from the design mark of open mining to the mark of the beginning of underground mining - N _0-p ; design mark of the beginning of underground mining - N _p ; the opening of all horizons of the quarry with an open method of development is carried out by a system of trenches of external and internal laying, with open-underground mining below the design mark of open mining operations with mine shafts in combination with horizontal underground workings; ore breaking within the limits of open-pit mining is carried out without spreading the sides of the quarry with one high ledge within 100 meters or more by a system of descending blast holes drilled from the bottom of the quarry and ascending drilled from underground workings; the collapsed ore from the zone of open-underground work through a system of exhaust openings enters the underground concentration horizon, where it is loaded into transport vessels using vibratory feeders [Agoshkov MI, Terentyev VI, Kazikaev DM and others. A comprehensive open-underground method for developing powerful steeply dipping ore deposits. In the book. The main directions of development of the open-underground mining method. Rotoprint IPCON USSR Academy of Sciences. 1987. - S.4-16].

The disadvantages of this open-underground mining method are the low efficiency of mining associated with the limitation of the productivity of traffic flows in terms of ventilation and the throughput of underground workings, as well as the increased risk of drilling and blasting near the quenched sides of the quarry.

The closest to the claimed invention by technical essence is a method of open-underground mining for shallow-dipping reservoir deposits with an incidence angle of not more than 50 °, which consists in the fact that a chamber recess is organized on the horizon of the planned bottom of the quarry, the parameters of which provide the collapse of the covering rocks to the surface. As a result of the release of ore in the caving zone, a funnel is formed adjacent to the caving wall, which is reliable protection against scattering of possible detachment of pieces of rock from the caving wall, which guarantees the safe operation of quarry equipment for cleaning caved rocks in the working area of the quarry [Demidov Yu.V. A comprehensive open-underground method of ore mining in the development of powerful inclined deposits. Mountain Information and Analytical Bulletin, 2002, No. 10, p.176-178].

The disadvantage of this open-underground mining method is the insufficiently high efficiency of mining operations during the completion of the field, due to the complexity of managing the caving process to guarantee a caving funnel to the surface under permafrost conditions and the limited size of the quarry in terms of a steeply falling column-like ore body.

The technical result of the invention is to increase the efficiency of mining while finalizing the ore body below the design level of the bottom of the quarry.

The technical result is achieved by the fact that in the method of combined open-underground mining of steeply dipping deposits, including mining the ore body in an open way to the design mark, open-underground method from the design mark of the quarry to the mark of the beginning of underground mining, while opening the ore body with the open mining method lead by a system of transport berm external and internal, with an open-underground mining method, they are carried out by underground mine workings in combination with a conveyor with berm, and in the open pit mining method in the working area of the open pit they form a recovery mine, open pit mining with the open-pit mining method is carried out with an interval of vertical lag from underground mining not less than the height of the working ledge, with ore breaking in the central parts of the ore body are carried out layer by layer with ledges by blasting of descending blast holes; in the contact part of the ore body, the ore is broken by a system of ascending fan wells drilled from underground mine workings with the formation of a catching workout, and the catching workout as open mining is reduced, is expanded by blasting vertical wells on each working ledge with a depth of at least 1/3 of the working ledge height.

To fully disclose the technical nature and advantages of the claimed invention in relation to deposits of kimberlite pipes located in the zone of permafrost in the harsh climatic conditions of Yakutia, an example of the completion of the field is presented, shown in figures 1, 2, 3, 4, 5.

Figure 1 shows the plan of the quarry in waste form to the design level (290 m) - the mark of the beginning of open-underground mining.

Figure 2 shows the plan of the quarry at the time of achieving the combined open-underground mining of the design level, i.e. the end of mining in the so-called transitional zone H _0-p .

In Fig. 3, a section shows the position of open-underground mining at the time of their completion and the scheme for opening the contact part of the ore body with underground workings in the transition zone, i.e. between the project mark of open mining and the mark of the beginning of underground mining.

Figure 4 shows a diagram of the development of open and underground mining in the transition zone, i.e. between the project mark of open mining and the mark of the beginning of underground mining.

Figure 5 shows the sequence of work on the sinking and expansion of the catching workings from underground workings and from the working horizons of open mining.

Designations in figures 1-5

1 - transport berm external location;

2 - internal transport berm;

3, 4, 5 - underground mining - adit, inclined ramps, ventilation well, respectively;

6 - ring breed drift;

7 - design mark of open cast mining (-290 m);

8 - pit side;

9 - the central part of the ore body at the border of the transition of open-underground mining to underground mining;

10 - the contact part of the ore body;

11 - loop steeply inclined transport berm;

12 - transshipment platform on the horizon (-290 m);

13 - temporary ore warehouse on the horizon (-290 m);

14 - orth-race;

15 - transshipment point on the horizon (-170 m);

16 - the redeemed side of the quarry in the zone of transition of open mining to open-underground mining;

17 - capture production;

18 - beaten ore in the area of underground mining of the contact part of the ore body;

19 - beaten ore in the open-cast mining zone of the central part of the ore body;

20 - face of the working horizon;

21 - temporary steeply inclined congress in the zone of open mining;

22 - front opencast mining in the central part of the ore body;

23 - downstream blast holes;

24 - vertical wells to expand the capture output;

25 - deviated wells to expand the capture output;

26 - ascending fan wells;

27 - ring ore drift;

28 - working ledges.

The proposed method involves conducting mining to the design 7 mark (-290 m) in an open way (Fig. 1) and below the design mark of 7 open cast mining (-290 m) (Fig. 2, 3, 4, 5) simultaneously in two ways: in the central part 9 of the ore body - in an open way, and on the adjacent part 10 of the ore body - in an underground way.

A kimberlite pipe to the design 7 mark (-290 m) to a depth of H ₀ = 600 m is developed by an open method (Fig. 1). The opening of the ore body is carried out by transport berms of external 1 and internal 2 deposits. The ore and rocks are broken by ledges, layer by layer, by blasting downstream wells 16–17 m deep drilled from working ledges (working ledge height is 15 m, non-working ledge is 45 m). The broken rock mass is loaded with the help of EKG-12.5 mining shovels and Letorn 1100 wheel loaders into Cat 785C high-capacity dump trucks and 2 is transported to the surface via transport berms 2, overburden is located in waste rock dumps.

To increase the efficiency of the ore body refinement below the design mark of 7 opencast mining and to the mark of the beginning of underground mining, the so-called transitional zone is allocated from the mark (-290 m) to the mark (-380 m), where the deposit is mined using a combined open-underground method ( figure 2, 3, 4, 5).

In the transition zone, the opening of the central part 9 of the ore body is performed by loop steeply inclined transport berms 11, which are built from the horizon (-290 m) to the horizon (-380 m) with a slope of no more than 20 °, with a total length of 250 m, placed along the side of the loading dock 12 located on the horizon (-290 m). Ore breaking during the detuning of steeply inclined transport berms 11 is carried out by ledges in layers in a blasting manner. The beaten ore is loaded with the help of front-end loaders to dump trucks with an articulated frame and delivered via steeply inclined transport berms 11 to the loading platform 12, loaded into mining dump trucks and delivered via transport berms of internal 2 and external 1 laying to the surface. The development of the front of 22 mining operations in the central part 9 of the ore body is carried out after opening the horizon (-350 m) with a temporary steep ramp 21.

The ore is broken at the mining in the central part 9 of the ore body by layer-by-layer breaking of working ledges 28 with a height of 15 m using downstream blast holes 23 drilled by SBSh-250MN machines. Transportation of broken ore 19 is carried out by two modes of transport. From the lower working horizons (-335 m) and (-350 m) along a temporary steep ramp 21, a loop steeply inclined transport berm 11 and to a temporary ore depot 13 located on a transshipment platform 12 (horizon (-290 m)), the ore is delivered by special vehicles for transporting ore along steep slopes (for example, articulated dump trucks or tracked tractor transport). From a temporary warehouse 13, ore is transported by dump trucks 9 (CAT 785C), with a lifting capacity of 135 tons through transport berms of internal 2 and external 1 laying to the processing plant or ore warehouse on the surface of the quarry. Ore loading both in the faces of 20 working horizons (-335 m) and (-350 m), and in temporary ore storage 13 is carried out by Letorn 1100 wheel loaders.

In order to ensure the continuity of mining operations during the transition from the open-cast mining zone to the combined open-underground mining zone and to ensure the opening of the contact part 10 of the ore body (Figs. 2, 3) in parallel with conducting open cast mining from aboard 8 quarry from the horizon ( -170 m) to the horizons (-305 ÷ -380 m), excavation of opening underground workings is carried out: adit 3, inclined ramp 4, and from the day surface with elevation. (+310 m), a vertical ventilation well 5 with a diameter of 3.5 m is drilled. Ring rock drifts 6, ring ore drifts 27 and run-in races 14 are also drilled (Fig. 4). Tunneling of underground workings is carried out by drilling and blasting along the bottom of the workings of cutting and boreholes (holes). The broken rock mass is loaded with an underground loader onto Atlas Copco MT 2000 underground dump trucks and transported via underground workings 14, 27, 6, 4, 3 to transfer station 15. Then, the rock mass is loaded onto mining dump trucks and internal transport berms 2 and external 1 laying is taken to the surface. The horizontal 3, 6, 27, 14 and inclined 4 underground workings are fastened using a metal arch support. Vent hole 5 is not attached.

The ore is blasted in the contact part 10 of the ore body (Fig. 4) by a blasting method. To do this, from the ring ore drift 27, the fans of the ascending wells 26 are drilled, the length of which is from 2 to 13 m, the distance between the individual fans of the wells is 2-3 m, the number of rows of fans of the wells 26 is 3-4 (i.e., the parameters of the fan wells 26 are determined by the design contour of the blasting area). After the explosion of fan holes 26 along the perimeter of the contact of the ore body and the host rocks (between the horizons (-350 m) and (-335 m) - mark of open mining), a catch mine 17 is formed, filled with crushed ore 18.

The beaten ore 18 from the recovery mine 17, falling under its own weight, fills the annular ore drift 27 and partially the orth-ride 14, where, using underground loading equipment, it is delivered to the annular rock drift 6 and loaded into the Atlas Copco MT 2000 underground dump trucks. Next ore through an annular rock drift 6, inclined ramp 4, adit 3 is delivered to the reloading point of open pit 15 located 120 m above the design mark for completion of open cast mining (Fig. 3, horizon (-170 m)). From the transshipment point 15, ore is discharged to the surface by mining vehicles. Thus, 90-85% of the recaptured ore from the volume of the catching mine 17 is removed.

To ensure that, as open mining is reduced, the possibility of the timely formation of a recovery mine 17, open cast mining is carried out in relation to underground mining with a vertical lag of at least no less than the height of the working ledge 28.

With the approach of open cast mining to the catching mine 17 along the horizon (-305 m), work is underway to expand it for the underlying horizon (-320 m) to the required width of 15 m (the sequence of work to expand the catching mine as the opencast mining decreases is shown in FIG. .5). To do this, at a distance of 5 m from the contour of the recovery mine 17, vertical wells 24 are drilled to a depth of 20 m, i.e. with an excess of 1/3 of the height of the working ledge 28. This depth of the wells 24 provides a sufficient amount of expansion of the catching production 17. When mining the horizon (-320 m), vertical wells 24 are drilled at a distance of 3 m from the contour of the catching working 17 and additionally drill inclined wells 25 since during the working off of this working ledge 28, the distance between the vertical wells 24 and the contour of the unexpanded part of the recovery mine 17 is 8 m, which exceeds the line of least resistance of blasted rocks. The required width of the catching excavation 17 on the underlying horizon (-335 m) will be 18 m.

The work on the creation of the recovery mine 17 and on its expansion on the underlying horizons is similar to the above. During the development of horizons (-320 m) and (-350 m), vertical wells 24 and deviated wells 25 are drilled at a distance of 3 m from the contour of the recovery mine 17, the drilling depth of vertical wells 24 is 20 m, and inclined wells 25 are drilled through the horizon. The width of the catching mine 17 during the period of mining horizons (-305 m; -320 m; -335 m; -350 m; -365 m; -380 m) on working ledges 28 will be equal to 10; fifteen; eighteen; twenty; 23 and 26 m.

The required total width of the catching mine 17 is determined from the values of the range of stones falling from the quenched side 16 of the quarry, taking into account the technical reserve according to safety rules

W _b = l _pad + l _app ,

where l _pad - the range of stones falling from the extinguished side 16, m;

l _zap - the technical reserve of the width of the catching output 17, 1 _zap = 1 ÷ 2 m

Open cast mining is carried out at a safe distance from the quenched sides 16 of the quarry, which is determined by the total required width of the catching mine 17 along its upper contour W _b (Fig. 2).

The results of calculating the necessary width of the open catching mine 17, established taking into account the range of stones falling from the quenched side 16 of the quarry according to the "Temporary guidelines for managing the stability of the sides of the quarry in non-ferrous metallurgy" [4], are summarized in table 1.

Table 1 No. Abs. mark, m Departed side height 16 quarries, m The required width W _b capture output 17, m one -290 45 10 2 -305 60 fifteen 3 -320 75 eighteen four -335 90 twenty 5 -350 105 23 6 -365 120 26

A trap mine 17 is created along the side 16 of the quarry in sections whose length should be equal to the length of the excavator block (L _b = 50 ÷ 100 m), within which 4 to 8 explosions of rows of ascending fan wells 26 are produced.

The depth of the recovery mine 17, taking into account that part of the broken ore 18 is left as a damper cushion, is 11-12 m. With this depth and a minimum width of 10 m, the recovery mine 17 will be able to take up to 800-850 m ^{3 of} scree and dumps in the area 10 m long. Such a capacity of the recovery mine 17 will be able to ensure the safety of open cast mining with a fairly high probability.

Thus, in a combined open-underground method, involving the formation of a catching mine to collect screes and dumps from the cleared sides of the quarry, an effective refinement of the ore body between the design mark for the completion of open mining and the mark for the start of underground mining can be ensured.

Claims (1)

A method of combined open-underground mining of steeply dipping deposits, including opencast mining of the ore body to the design mark, open-underground mining to the mark of the beginning of underground mining, while opening the ore body with the open mining method is carried out by a system of external and internal laying berms, when open -the underground mining method is carried out by underground mines in combination with transport berms, moreover, in the working area of a quarry with an open-underground mining method the workings form a trapping mine, characterized in that in the open-underground mining method, open-cast mining is conducted with an interval of vertical lag from underground mining not less than the height of the working ledge, and ore breaking in the central part of the ore body is carried out layer by layer with ledges by blasting of the downstream explosive wells, in the contact part of the ore body, the ore is broken by a system of ascending fan wells drilled from underground mine workings with the formation of catching workings and at the same time, the capture output as the opencast mining is reduced is expanded by blasting vertical wells on each working ledge with a depth of at least 1/3 of the working ledge height.

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