RU2425219C1 - Open development method of mineral deposits - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method involves construction of working flank, drilling-and-blasting preparation of rock for excavation, excavation and transportation of rock. Working flank of pit of convex-concave shape is formed during drilling and preparation of horizon with advance. At that, frontal work advance speed on projections forms working platforms of above-lying benches with width which is bigger than adjacent below lying benches, and working platforms of below lying overburden benches are formed of the width which is bigger than that of adjacent above-lying working platforms.

EFFECT: reducing the scope of work on removal of overburden and providing maximum capacity of the pit.

2 tbl, 2 dwg

Description

The invention relates to the mining industry and can be used for the detuning of the working side of the quarry.

There is a method of open mining of minerals (application of the Russian Federation No. 2005135900/03, IPC E21C 41/00), including the detuning of the working side with the creation of ramps for transporting overburden to dumps, increasing the depth of the quarry, reducing the number of wells and increasing the safety of work. The disadvantages of this method are the need to create exits for transportation of overburden to dumps located near the quarry in the zone of the second and subsequent stages of field development, as well as the construction of inclined elevators for transporting rock mass from lower horizons when deepening the work, which leads to an increase in the stripping ratio.

There is a method of open mining of minerals (application of the Russian Federation No. 2003135554/03, IPC E21C 41/26), including detuning and spacing in the center of the section of a well-shaped mine with vertical ledges with small parameters for mining steeply inclined layers of the next stage after changing the development order of overburden and ore zones .

The disadvantage of this method is the detuning of the well-shaped production before mining the layer, which increases the time of deepening and mining of the horizon.

There is a method of open mining of minerals (RF patent No. 2294434, IPC E21C 41/26, 09/27/2005), taken as a prototype, which improves the efficiency of mining by reducing the volume of overburden in the deep, limited in terms of quarries while maintaining the completeness of the excavation .

The method includes, at the first stage, the detachment of the quarry sides with an angle of inclination below the maximum permissible stability, drilling and blasting of rocks for excavation, transportation of ore and overburden by capital transport exit by wheeled transport, at the second stage, the formation of a transshipment point site and completion to the design depth with the detuning of the sides with tilt angles extremely permissible in stability. At the same time, the capital ramp is cut from the site of the transshipment point, increasing its longitudinal slope, ore pillars left at the first stage are worked out, the quarry side is rebuilt with ultra-high ledges, the lower ledge is rebuilt at the contact of the ore body, a temporary ramp is built in the quarry part, ore and overburden are transported to the site of the transshipment point by caterpillar transport, and for completion to the design depth, a capital congress is dumped and ore pillars are being finalized under a temporary congress.

The disadvantage of this method is the formation between adjacent horizons of the working platforms of the minimum width, which allows to achieve an angle of inclination in this area of not more than 50-55 ° at the maximum possible value of 75-80 °. The formation of parallel transport berms of the first and second stages with common adjoining platforms will clearly lead to an underestimation of the slope of transport exits at the second stage, i.e. to the overrun of transport, which does not allow to use the geometric space to the fullest extent and reduces the volume of ore mining or, when the ore is fully refined, leads to an increase in the overburden volume of the first stage of mining. All this reduces the efficiency of mining the field.

The technical result is to reduce the amount of work to remove overburden and provides the maximum productivity of the quarry.

The technical result is achieved in that in a method of open mining of minerals, including the detuning of the working side, drilling and blasting the rocks for excavation, excavation and transportation of rock, form the working side of the quarry concave-convex shape when opening and preparing the horizon with a deep, while the speed of advancement of the front of work on the ledges forms the working platforms of the overlying mining ledges with a width greater than adjacent underlying ones, and the working platforms of the underlying overburden ledges form a width greater than with ezhnyh overlying worksites.

The method of detuning the working side of the quarry is as follows.

In accordance with the classification of reserves according to the degree of preparedness (A.I. Arsentyev. Laws for the formation of a working area of a quarry // LGI. - 1986), reserves ready for excavation (lead overhangs for overburden (BC Khokhryakov. Designing quarries // M .: NEDRA - 1980)) are in the reserve strip of work sites, outside their minimum width. Therefore, the width of the reserve strip is an important factor in the classification of reserves of rock mass in quarries according to preparedness.

Regulation of the volume of reserves ready for excavation on the ledges, the size of the reserve strip of working sites allows for the optimal formation of the working area of the quarry, which corresponds to the established productivity of the quarry and the operating ratio of stripping.

For example, consider the working side of a quarry folded with 14 ledges. The height of the ledges adopted at the quarry, h = 15 m, the required depth of the recess h _g = 15 m / year, the minimum width of the working platform V _m = 45 m, the average annual operational productivity of excavators Q _e = 830000 m ³ / year, the angle depth directions β = 23 °.

To determine In _i - the average width of the working platform on the ledge - it is necessary to determine the area of the working site S _i and the length of the front of the work on the ledge L _i on the combined mining plan. The normative movement of the lower ledge (according to formula 1) for the quarry under consideration U _n = 65.70 m / year.

The results of calculations of the normative movement of the ledges, provided that the minimum width of the working platforms and the minimum required number of excavators in the quarry under consideration are presented in Table 1. As the data in Table 1 show, the required number of excavators working on the ledge is a fractional number, therefore, to ensure uniform movement of all the ledges, it is necessary to move the excavators from the ledge to the ledge or have their reserve.

Using the normative advancement of the working zone of the quarry established above, it is possible to obtain the magnitude of the advancement of the front of work on working ledges and the minimum required number of excavators at the end of the preparation of any horizon. In open pit mining, it is necessary to ensure not only normative, but also the movement of the open pit working area, which corresponds to the established open pit productivity in terms of rock mass and the demand for ore from this pit.

Installed productivity corresponding to periods of relative stabilization of demand for raw materials of a given quarry at the time of completion of preparation of any given horizon, both for mineral resources (P) and overburden (V)

where ΔP 'is the difference in the extracted volumes of minerals with the established productivity of the quarry in minerals and productivity with the normative movement of working ledges, m ³ ;

ΔV 'is the difference in the recoverable volumes of overburden at the established quarry productivity for overburden and productivity for the regulatory movement of ledges, m ³ .

Table 1 Normative advancement of the front of work on the ledges of the iron ore quarry and the number of excavators required for this Ledge mark L _i , m S _i , m B _i , m

l _i , m n _i , the excavator. 175 1320 71808 54,4 585 696.3 -45.6 0 160 1450 75835 52.3 540 641.9 -36.2 0 145 1380 76866 55.7 495 589.6 -28.9 0 130 1260 71568 56.8 450 533.9 -18.2 0 115 1180 63956 54,2 405 477.1 -6.4 0 one hundred 1160 61944 53,4 360 422.9 2,8 0.05 85 1020 53346 52.3 315 369.5 11.2 0.2 70 980 50372 51,4 270 317.2 18.5 0.33 55 930 48546 52,2 225 265.6 25.1 0.42 40 850 45985 54.1 180 213.4 32.3 0.5 25 730 40588 55.6 135 159.3 41,4 0.55 10 690 36156 52,4 90 103.7 52 0.65 -5 610 31293 51.3 45 51.3 59,4 0.66 -twenty 520 - - - - 65.7 0.62 Total 140080 728263 51.72 - - 15,64 3.98

The difference in the extracted volumes of minerals in the quarry with the established productivity for minerals and for productivity in the normative movement of ledges

where ΔB ' _pi is the difference in the movement of the working platforms of mining ledges, m;

L _pi - the length of the front of work on minerals on the i-th ledge, m

The difference in the recoverable overburden volumes in the quarry with the established overburden productivity and for the overburden productivity with the normative step movement

where ΔB ' _bi - the difference in the movement of the working stripping strips, m;

L _bi - the length of the front of stripping operations on the i-th ledge, m

As a result of the advancement of the working ledges by an amount greater than in the case of normative advancement, on the working ledges more than the minimum areas were formed, i.e. there is a reserve strip of work sites characterizing the availability of volumes of reserves ready for excavation on ledges.

For the quarry as a whole, the volume of minerals in the reserve strips of the working sites is reserves ready for excavation, at the time of completion of the preparation of this horizon

where n _pi is the number of mining excavators on the i-th ledge.

Mine work reserve at the time the horizon is completed

Overburden volume in the reserve strip of the working platform of the i-th overburden ledge - overtaking ahead

where T _vi - the reserve of work of the i-th overburden ledge, months;

L _WB - the length of the block overburden excavator, m;

Q _ev - overburden excavator productivity, m ³ / month;

ΔB _vi - the width of the reserve strip of the i-th overburden ledge, m

For the quarry as a whole, the amount of overburden in the reserve strips of the working sites is the advance of the overburden, at the time of completion of the preparation of this horizon

where n _bi is the number of overburden excavators on the i-th ledge.

Reserve overburden career at the time of completion of this horizon

Thus, the value of the reserve for minerals and overburden does not depend on the length of the front of work on the ledges, the length of the excavator blocks and when the maximum length of the front of work and the maximum number of excavators are met, if direct proportionality is observed (n _pi and n _bi are integers)

.

.

The distribution of ΔV 'and ΔP' values on the ledges along the height of the working board determines the level of reliability of the mining system-quarry.

As it was established above, at the maximum possible value of reserves ready for excavation in the upper production ledges and overburden advances in the lower overburden, the reliability of the mining quarry system will be close to maximum.

The laws of formation of career space are such that the length of the front of work of the overlying ledges is longer than the underlying ones, and this allows us to replace the distribution of ΔV 'and ΔP' with the distribution of ΔB ' _pi and ΔB' _in .

In general, for mining ledges it is necessary to provide

advancement of the front of work under which the condition

ΔP _(i-1) > ΔP _i > ΔP _{(i + 1)}

or

For overburden steps in this case, the following condition must be met

ΔV _(i-1) > ΔV _i > ΔV _{(i + 1)}

or

Common to all working ledges of the quarry is the condition

B _i > B _min .

As a result of extraction of the volume ΔV 'and production of the volume ΔP', the working board of the quarry will occupy a position corresponding to the established productivity of the quarry at the time of completion of the (n + 1) -th horizon, and the working platforms on the ledges will form in a position different from the normative.

Thus, the width of the reserve strip of the working platform on this horizon is formed when extracting the volumes of the rock mass both on this horizon and on the overlying one. Width of working platforms on mining ledges

When establishing the width of the working platforms of overburden and mining ledges, the conditions must be met

where ΔB ' _p1 is the difference in the movement of the working platforms for the upper production ledge, m;

_ΔB ' _in - the difference in the movement of the working platforms for the lower overburden ledge, m

The distribution of ready-to-mine reserves and overburden lead, at the time of completion of a series or all horizons, providing a high level of reliability of the mining system-quarry, allows for optimal planning of the development of mining operations. The results of calculating the values of reserves ready for excavation and overburden lead for an iron ore quarry developing a steeply dipping deposit of complex structure for a ten-year mining period are presented in Fig. 1 (Table 2) (1 - volume of reserves ready for excavation, thousand m ³ ; 2 - excavation horizon; 3 - preparation horizon; 4 - horizon 40; 5 - horizon 25; 6 - horizon 10).

The ledge distribution of the reduction in the movement of work sites is related to the question of maintaining the optimal value of the reserve strip of work sites. If we extend the reduction in the movement of work sites in the reserve zone to overburden ledges, then with an increase in ΔB ' _i on the upper production ledge, this value can be increased on the overburden benches and thereby attribute the extraction of the corresponding overburden volumes to a later date.

Improving the reliability of the mining system-quarry can be achieved in the case when the volume of reserves ready for excavation of the overlying mining ledge is greater than the underlying; for overburden benches - overtaking ahead (analogue of volumes of reserves ready for excavation for overburden benches) of the overlying step should be less than that of the underlying. Thus, the working side of the quarry in the section should take a concave shape in the overburden and convex in the mining.

On the intermediate plan of the iron ore quarry (figure 2) presents the design position of the working side and the optimal position of the ledges (dashed line), characterized by an increase in the reliability of the mining system-quarry from 0.48 to 0.63.

Claims (1)

A method of open mining of minerals, including the detuning of the working board, drilling and blasting the rocks for excavation, excavation and transportation of rock, characterized in that the working board is formed by a concave-convex pit when opening and preparing the horizon with a recess, while the speed of advancement of the front of work on ledges forms the working platforms of the overlying mining ledges with a width greater than adjacent lower ones, and the working platforms of the underlying overburden benches with a width greater than adjacent overlying p bochih sites.

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