RU2661769C1 - Method of refinement of deep kimberlite quarries - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to the mining industry and is created with reference to the development of deep kimberlite quarries in the extreme climatic conditions of the permafrost zone of the North. Method comprises the construction of a high vertical bench along the contour of the tube with preliminary pre-splitting, the strengthening of the proximal rock mass with cable ties from the underground excavations through the wells, shipment of diamond-bearing ore with its transportation using the motor vehicles through the spiral stems to the concentrating mill. Moreover, the spiral stems in the completion area pass from the side of the pit, while for working off the side pillars at a certain distance from the vertical slope, the annular horizontal excavation is constructed, the slope is strengthened with the cable ties, where the ties are located along and across the vertical bench, placing the prism of a possible collapse into the rope basket, which is fixed in the annular working with the cables to the channels, and transportation of ore is carried out both through the exits, which traverse along the ore body, and through the spiral workings with temporary storage of part of the ore at the site during the completion of ore exits.

EFFECT: technical result is the increased efficiency of refinement of kimberlite quarries under the conditions of transition to the development of reserves of deposits by means of the underground method.

1 cl, 1 tbl, 4 dwg

Description

A way to refine deep kimberlite quarries

The invention relates to the mining industry and is created with reference to the completion of deep kimberlite quarries in extreme climatic conditions of the permafrost zone of the North.

There is a method of finalizing kimberlite quarries, including the formation of a high vertical ledge, installing a metal safety wall on its safety berm, working out the deep section of a kimberlite pipe using milling-type electric excavation machines, delivering the rock mass from the bottom of the quarry to the surface using tower cranes or aerostatic lifts, providing completeness of the extraction of minerals in the open method (see. Tochilin V.N. Resource-saving technologies p the development of small kimberlite pipes / Sat: Actual problems of the development of kimberlite deposits: current status and prospects of solution, Mater.International Scientific and Practical Conf. (Mirny, 2001) - M: Publishing House "Ore and Metals ", 2002. - S. 346-351).

The disadvantages of the method are the reduced safety of technological operations when conducting mining operations on the soles of vertical ledges, the limited scope of its application due to the insignificant height of the tower lifts, low productivity of the vertical scheme of lifting the rock mass and additional costs for mounting and dismounting the equipment of the lifts.

There is also known a method of extracting minerals under the sides of the quarry, including opening and extracting it in separate blocks, without violating the stability of the side, by subsequently loading the lower part of the side of the side of the side with overburden to compensate for its weakening (see SU No. 926284, class E21C41 / 00, publ. 07.05.82).

The disadvantages of the known solutions are the need for additional re-excavation of rocks, a limited area of application mainly for horizontal reservoir-like deposits and significant loss of minerals due to the abandonment of undeveloped safety pillars.

There is a method of excavating near-side mineral pillars during quarrying, including the formation of a stable vertical slope of the bead by forming a gap at the ore contact with the rock, drilling the pillars from the surface, breaking them into the mined quarry space, strengthening the contact rock mass, and shipment of the broken ore by excavators to dump trucks it along career roads (see Rylnikova M.V. Integrated development of ore deposits in a combined way. - Magnitogorsk, Publishing House of MGU, 1998.- P. 111-12 0).

The disadvantages of this method are the low efficiency due to the significant complexity and the complexity of the work to strengthen the contact rock mass and the increased danger to the operation of mining equipment caused by possible rock failure due to the thawing of the fractured contact mass of permafrost.

Closest to the invention in technical essence is a method for finalizing deep kimberlite quarries, including the construction of a high vertical ledge along the tube contour with preliminary slitting, strengthening the contact rock mass, installing catching shelves on a vertical slope, and shipment of ore with removal at temporary exits dumped from waste rocks (see Vlasov V.M., Androsov A.D. Technologies for open diamond mining in the permafrost zone - Yakutsk: Publishing House of the YaNTS SB RAS. 2007. P. 202-204, 213-218).

The known solution is characterized by low efficiency caused by significant volumes of overburden excavation operations during quarrying, additional costs for the construction of spiral ramps from waste rocks and a decrease in the safety of mining operations under high vertical slopes.

The objective of the present invention is to increase the efficiency of refinement of kimberlite quarries in the transition to the development of reserves of deposits by underground mining.

The technical effect obtained when solving the problem is expressed in increasing the completeness of the extraction of diamond ores and ensuring the safety of work under high vertical slopes when using existing mining equipment and without additional capital investments.

To solve this problem, the method of finalizing deep kimberlite quarries involves driving from the side of the quarry in the zone of completion of spiral trunks, while to work on the pillars at a certain distance from the vertical slope, an annular horizontal excavation is constructed, the slope is strengthened with cable ties, and the couplers are placed along and across the vertical ledge , placing the prism of a possible collapse in a cable basket, fixed in an annular mine with cables to the channels, and ore transportation is made They are dressed both through the exits passed through the ore body, and spiral workings with temporary storage of part of the ore at the work site during the completion of the ore exits.

A comparative analysis of the characteristics of the claimed solution with the signs of analogues indicates the conformity of the claimed solution to the criterion of "novelty."

In the new method, new features in comparison with known solutions are:

• the use of spiral underground workings, passed from the side of the quarry to the depth of its being developed section;

• creating a cable tie along the slope and the upper platform of the vertical ledge, placing the prism of a possible collapse in the cable basket;

• the construction of an annular horizontal mine with the placement of channels in it to secure the cable ties;

• Creation of a temporary ore warehouse at the site during the completion of ore congresses.

All these new features eliminate the shortcomings of existing methods for finalizing deep kimberlite quarries and provide the following enhanced new positive properties:

• the use of spiral underground workings in the completion zone precludes the production of additional overburden volumes for excavating the onboard pillars of ore;

• creation of a cable tie along the slope and the upper platform of the vertical ledge and the subsequent formation of the cable basket provide safe working conditions under vertical slopes;

• temporary storage of ore on the working platform of the ledge during the completion of ore congresses ensures the full extraction of diamond-containing ores in the process of completing mining operations.

The claimed solution is illustrated by drawings. The figure 1 shows the layout of the spiral underground workings in the area of completion of the quarry in a transverse section; figure 2 is a plan of the location of the spiral underground and opencast mining; figure 3 - cable tie to hold the prism of a possible collapse in a steady state; figure 4 - sequential position of the front of mining during the completion of the quarry.

The method is as follows.

Quarry 1 has been worked out to the design depth, characterized by position 2. In this case, ore pillars 4 remain along the contour of the ore body 3 (see Fig. 1). For data extraction from pillars with an elev. 0 side of the quarry pass inclined spiral underground workings 5 to the depth of its being developed section (mark -60 m). Then, along the contour of the ore body 3, spiral congresses 6 pass to elevation. –30 m (see Fig. 2). As the formation of working sites 7 and 8, respectively, at the horizons of -15 m, -30 m and the movement of the front of the work to a sufficient distance across the ore body 3 (elevation -30 ÷ -60 m) pass a deep trench 9.

On mark -60 m dock the deep trench 9 with the spiral underground workings 5. Thus, from the bottom of the open pit 2 to the day surface, a new transport scheme is formed through the underground workings 5 and the existing spiral ore exits 6.

In addition, to ensure the safety of work under a vertical ledge 10 and to maintain the prism of a possible collapse 11 in a stable state, it is strengthened with cable ties 12 laid in wells and secured with channels 13 in an annular underground mine 14. Moreover, the underground mine is placed at a certain distance from the vertical slope ledge 10 (see Fig. 3).

Mining operations in the quarry space during its development are developed in the following sequence.

First, work out horizons of -15 and -30 m. Then proceed to the development of horizons of -45 and -60 m. In the process of eliminating ore pillars 4 and ramps 6 form a temporary ore warehouse 15 at the bottom of quarry 2 (see Fig. 4). After the formation of a new transportation scheme through underground workings 5, they begin to finalize the on-board pillars of ore 4 and eliminate the ore exits 6. The quarry is refined using the existing mining transportation equipment without additional capital investments, i.e. excavator and car complexes.

Thus, the developed method provides an effective and safe completion of deep kimberlite quarries in the context of the transition to the development of reserves of underground deposits.

An example of a specific implementation of the method

The initial data for the calculations are as follows:

- the final depth of the quarry, N _to = 330m;

- depth of the section under development, N _d = 60m;

- the diameter of the kimberlite pipe, d = 200m;

- the height of the working ledge, h _y = 15m;

- the general angle of slope of the side of the quarry, ɤ = 50 °;

- the cost of developing 1 m ³ of rocks in an open way, With _about = 3.41 dollars / m ³ ;

- the cost of developing 1 m ³ of rocks by underground method, With _p = 10.2 dollars / m ³ ;

- the slope of the spiral ramps on the side of the quarry, β = 4 °;

- the slope angle of the working ledge, α = 75 °;

- the width of the spiral exit, W _with = 20m;

- the cross-sectional area of the inclined shaft for moving dump trucks, S _p = 134m ² ;

- the slope of the inclined trunk, ∆ = 4 °.

The calculations are performed in the following sequence:

1. The volume of ore left on the sides of the quarry as technological losses - V _p

_с * h² _у * ctgβ,V _p =

_c * h ² _y * ctgβ,

where W _with - the width of the spiral exit, m;

h _y - the height of the working ledge, m;

β - the slope of the spiral exit, m

those. V _p = 4 * 0.5 * 15 ² * ctg4 ° +15 ² * 20 * ctg 4 ° + 2 * 15 ² * 20 * ctg4 ° + 3 * 15 ² * 20 * ctg4 ° + 4 * 15 ² * 20 * ctg4 ° = 6435 + 65250 + 130500 + 195750 +261000 = 658935 m ³

2. Volumes of production of additional overburden for the extraction of pillars - V _in

a) overburden volumes during quarry mining to a depth of 300 m - V ₁

V ₁ = (S ₁ + S ₂ ) * 0.5 * N _k1 ,

where N _k1 - the depth of the quarry, m;

S ₁ , S ₂ - respectively, the area of the bottom of the quarry and the area on the surface, m ² ;

² = 3,14 * 100² = 31400 м² = 31,4 тыс.м³ S ₁ =

² = 3.14 * 100 ² = 31400 m ² = 31.4 thousand m ³

²= 3,14 * (R + H * ctg

) = 3,14 * ( 100 + 300 * ctg50° ) = 400111 м² = 400, 1 тыс.м² S ₂ =

² = 3.14 * (R + H * ctg

) = 3.14 * (100 + 300 * ctg50 °) = 400111 m ² = 400, 1 thousand m ²

* H_к1 = 0,5 * (31400 + 400111) * 300 = 64726650 м³ = 64,7 млн.м³ V ₁ =

* H _k1 = 0.5 * (31400 + 400111) * 300 = 64726650 m ³ = 64.7 million m ³

b) overburden volumes during quarry mining to a depth of 360 m - V ₂

V ₂ = (S ₁ + S ₂ ) * 0.5 * N _k2 ,

where N _k2 - the depth of the quarry of the second stage, m;

²= 31400 м² S_one =

²= 31400 m²

* ( R+ H_к2 * ctg

) )² = 3,14 * (100+360 * 0,839)² = 507436 м² = 507,4 тыс.м² S ₂ =

* (R + H _K2 * ctg

)) ² = 3.14 * (100 + 360 * 0.839) ² = 507436 m ² = 507.4 thousand m ²

* H_к2 = 0,5 (31400 + 507436) * 360 = 96990480 м³ = 96,99 млн.м³ V ₂ =

* H _k2 = 0.5 (31400 + 507436) * 360 = 96990480 m ³ = 96.99 million m ³

V _in = V ₂ - V ₁ = 96.99 - 64.7 = 32.29 million m ³

That is, for the extraction of onboard pillars of ore in the traditional way (with the separation of the sides of the quarry), 32.29 million m ^{3 of} overburden rocks will need to be removed.

Therefore, the cost of the production of stripping operations for the extraction of pillars of ore with traditional technology Z ₁ will be

З ₁ = V _в * С _о ,

where With _about - the cost of developing 1 m ³ of rocks in an open way, $ / m ³

З ₁ = 32.29 * 3.41 = 110.1 million dollars.

3. Recommended technology does not require overburden operations. Costs are provided only for the excavation of inclined spiral trunks, passed from the side of the quarry with a slope of 4 ° to a depth of 60 m.

a) the length of the inclined shaft is calculated by the formula,

=

= 860 м,L _stem =

=

= 860 m,

where L _stem - the length of the inclined trunk, m

b) the scope of work for sinking the inclined shaft will be equal,

V _st = S _st * L _st = 120 * 860 = 103,200 m ³ = 103.2 thousand m ³ ,

where S _stem - the cross-sectional area of the trunk, m ² ,

S _shaft = 120m ²

Then the cost of sinking the barrel Z ₂ with the recommended technology will be,

З ₂ = V _stem * С _p ,

where C _p - the cost of developing 1m ³ rocks under the underground method, $ m ³

З ₂ = 103200 * 10.2 = 1.06 million dollars

The economic effect is calculated as the cost difference with the traditional and recommended technologies for the extraction of pillars, i.e.

E = Z ₁ - Z ₂ ,

where E is the economic effect of the implementation of the new technical solution, mln.

E = 110.1-1.06 = 109.04 million dollars.

The table shows the expected technical and economic indicators from the introduction of a new technology for refinement of the quarry. From the results it follows that the developed new technology for quarrying with the use of underground workings provides an additional profit to the diamond mining company in the amount of 109.4 million dollars. At the same time, the best conditions will be created for mining deep horizons of kimberlite pipes in the transition from open work to underground. In addition, the development should be recommended for implementation at existing enterprises in the conditions of decreasing mineral reserves of diamond ores.

Table

Expected technical and economic indicators from the introduction of a new technology for refinement of the quarry

№№
n / n The name of indicators Designations Technologies Traditional Recommended one Final quarry depth, m N _to 300,0 360,0 Including final depth, m N _k2 - N _k1 60.0 60.0 2 The diameter of the kimberlite pipe, m d 200,0 200,0 3 The volume of pillars of ore in the sides of the quarry, thousand m ³ V _p 658.9 658.9 four Production volumes of stripping operations for the extraction of pillars of ore, mln.m ³ Vc 32.29 - 5 The volume of work on the sinking of inclined shafts, thousand m ³ V _stem - 103,2 6 The cost of developing 1 m ³ of open-cast rock, $ / m ³ With _about 3.41 - 7 The cost of developing 1m ³ of rocks underground, $ / m ³ C _p - 10,2 8 Stripping costs, mln USD W ₁ 110.1 - 9 Exploration costs of inclined spiral-shaped trunks in the completion zone, mln USD H ₂ - 1.06 10 Lower costs for the extraction of onboard pillars of ore, mln USD E - 109.04 Note: cost data are taken from actual indicators of development of 1m ³ of rocks at ALROSA enterprises

Claims (1)

A method for finalizing deep kimberlite quarries, including the construction of a high vertical ledge along the tube contour with preliminary slitting, strengthening the contact rock mass with cable ties from underground workings through wells, shipment of diamond-containing ore with road transport through spiral trunks to an enrichment plant, characterized in that it has spiral trunks in the completion zone, they pass from the quarry, while for working off the side pillars at a certain distance tons of vertical slope, an annular horizontal excavation is constructed, the slope is strengthened with cable ties, and the couplers are placed along and across the vertical ledge, placing the prism of possible collapse in a cable basket fixed in the ring working with cables to the channels, and ore transportation is carried out as through exits passed through the ore body and spiral workings with temporary storage of part of the ore at the working site during the completion of ore exits.

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