RU2698752C1 - Method for driving of inclined shafts and horizontal underground mines in cryolithozone conditions - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to the mining industry and is intended primarily for development of diamond-containing ores in cryolite zone using inclined shafts and underground mines. Method includes application of non-explosive technologies of rock mass destruction, their selective extraction, fixation of excavations by mechanized complex and transportation of rock mass. At that, in order to increase efficiency of driving of inclined shafts and horizontal underground mines in cryolite zone conditions due to elimination of negative effect of destructive element of tunneling equipment in bottomhole zone, boreholes and underground mines pass using laser process unit. Working face of the mine is treated with a laser beam from its center, for which a cylindrical hole with depth of 1 m is first created, which is then gradually expanded, conically shaped by laser beam processing, forming in the plane of the working face a continuous process of deepening and expanding the funnel-shaped cavity to the final contour of the bottomhole plane. Drilling of working in kimberlites by means of laser beam is performed by narrow cuts excluding formation of mechanical stresses in developed massif of kimberlite and preserving integrity of diamonds contained in it.

EFFECT: use of the present invention will make it possible to preserve integrity of the surrounding massif of rocks, to improve quality of extracted mineral raw material at extraction of kimberlites and ecological purity of development.

1 cl, 1 tbl, 4 dwg

Description

The invention relates to the mining industry and was created primarily for the development of diamond ores in the permafrost zone using inclined shafts and underground workings.

There is a well-known drilling and blasting method of driving underground workings, including drilling of cut-in, jack-off and contouring holes in the face and their subsequent loading and blasting (see Mine and Underground Construction: Textbook for High Schools. - M.: Publishing House of Moscow State Mining University. - 3rd edition, revised and supplemented, volume 3, 2003. - 732 p. - S. 210-234).

A disadvantage of the known solution is the destruction of the contour mass during the explosion of contouring charges, which can provoke rock outfalls in the bottomhole space and create a dangerous situation when people work in the bottomhole space of underground mining.

There is also a method of sinking horizontal and inclined workings, shafts using a tunneling harvester of selective destruction, including an arrow-shaped actuator equipped with a milling crown with a cutting tool (see Mining Encyclopedia, Moscow, Sovetskaya Encyclopedia Publishing House, 1989, Volume 4. - S. 267-268).

The disadvantage of this method is the limited scope, mainly in coal mines, since when performing tunneling works on hard rocks and the development of permafrost, the permafrost zone rarely increases not only the wear of cone and milling crowns, but also significantly increases the energy consumption, which results in significant labor costs.

Closest to the invention in technical essence is a method of conducting inclined and horizontal underground workings using a complex of tunneling equipment (see Mountain Encyclopedia, Moscow, Sovetskaya Encyclopedia Publishing House, 1989, Volume 4. - P. 268 - 269), including mechanical destruction mass, loading and transportation of rock mass, as well as fastening workings mechanized complex.

The disadvantage of this method is the low efficiency of sinking caused by the use of a complex set of equipment when sinking underground workings, which includes techniques for destroying the massif, loading and transporting the rock mass, securing the face in the aggregate, which negatively affect not only the state of the surrounding massif, but also sanitary -hygienic labor standards in the bottomhole space. Moreover, when developing kimberlite ores while preserving the natural qualities of jewelry stones, the use of this method entails the destruction of large-class diamonds.

The objective of the present invention is to increase the efficiency of driving inclined shafts and horizontal underground workings in the permafrost zone by eliminating the negative impact of the destructive organ of the tunneling equipment in the bottomhole zone.

To solve this problem, the method of driving inclined shafts and horizontal underground workings in the permafrost zone, including the use of non-explosive technologies for the destruction of the rock mass, their selective excavation, fastening the workings with a mechanized complex and transporting the rock mass, differs in that in order to increase the efficiency of driving inclined shafts and horizontal underground workings in the permafrost zone by eliminating the negative impact of the destructive organ of the tunneling equipment bottomhole ore, shafts and underground workings are carried out using a laser technological installation, and the bottom of the workings is treated with a laser beam from its center, that is, first a cylindrical hole is created up to 1 m deep, then the cylinder diameter is gradually expanded, giving it a conical configuration by laser treatment beam, forming in the face plane a continuous process of deepening and expanding the funnel-shaped cavity to the final contour of the face plane, and driving the mine through kimberlites with p Using the power of the laser beam, narrow cuts are carried out, eliminating the formation of mechanical stresses in the developed kimberlite massif and preserving the integrity of the diamonds contained in it.

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 proposed method, new features in comparison with the prototype are:

- the use of a laser technological installation for driving underground workings;

- the use of a new complex of mining and loading equipment, incorporating a laser processing unit;

- the formation of a funnel-shaped configuration of the face in its central part, constantly expanding to the final contour of the face in the course of mining operations;

- laser processing of kimberlites with narrow cuts, as well as the formation of the contours of the face area.

All indications of new signs eliminate the disadvantages of existing methods of driving inclined tables, horizontal underground workings and provide the following enhanced positive properties:

- the use of a laser technological installation for driving underground workings ensures the efficient implementation of explosive-free preparation of rock mass during mining and preparatory work;

- the use of a new complex of mining and loading equipment with a laser processing unit allows you to maintain the integrity of the massif in the process of mining;

- the creation of a funnel-shaped construction of the face and its constant expansion to the final contour in the process of tunneling provides the best mode of destructible effect of the laser beam;

- laser processing of the production loops and the destruction of kimberlite by narrow cuts preserves the stability of the marginal massif and the integrity of diamond crystals during mining operations.

The claimed technical solution is illustrated by drawings, where figure 1 shows the scheme of the LTU when driving an inclined shaft in the complex: loader, belt feeder and dump truck on the surface; figure 2 - scheme of the LTU when driving horizontal underground mining complex consisting of: loader, belt conveyor, belt reloader, dump truck on the surface; figure 3 - scheme of the LTU when driving a horizontal underground mine consisting of: a scraper loader, a dump truck and on the surface with overloading the rock mass from the dump truck into the dump truck; figure 4 is a design diagram for determining mining objects during the development of a buried placer, where A is a contour of a buried placer by the traditional open method, B is a contour of a buried placer by the claimed method.

The method is as follows.

The inclined shaft 1 is drilled using an LTU 2, which processes the face plane with a laser beam 3 in circles from its center to the final contour 4 of the face plane (see Fig. 1). Loaded at the bottom of the rock mass 5, the loader 6 transports along the inclined shaft 1 to the hopper 7, from which it is unloaded into dump trucks 8, delivering the rock mass to the destination. To ventilate the bottom-hole space, a fan 9 is installed at the mouth of the inclined shaft, which pumps fresh air through the ventilation pipe 10 into the working area of the LTU. Thus, according to such a new technological scheme, an inclined shaft is drilled using laser technology.

Another embodiment of a new technical solution for horizontal underground excavation is a tunneling complex with a LTU, which includes a loader, a conveyor belt, a belt loader and a dump truck on the surface (see Fig. 2). Horizontal underground excavation are using LTU 2 as follows. The rock mass 5 destroyed by the laser beam 3 is loaded by a loader 6 through a loading device 11 onto a conveyor belt 12, which delivers the load to the surface along an inclined shaft 1. Then, using the loading conveyor 13, the rock mass is loaded into dump trucks 8, which deliver it to its destination. To ventilate the bottom-hole space, large-diameter ventilation holes 14 are drilled through which contaminated air is removed by the fan 15.

The next new variant technical solution is a tunneling complex: LTU, a dump truck used in underground mining (for example, the production of the Mogilev plant) and a hopper feeder (see Fig. 3).

Horizontal underground excavation is carried out using LTU 2 with the loading of the rock mass 5 by a harvesting machine 16 into dump trucks 17, which are delivered along an inclined shaft 1 to an assembly hopper 18 located on the day surface. From the assembly hopper by dump trucks 8, the rock mass is transported to destination points as necessary. Ventilation of the bottomhole space in the process of underground mining is carried out by a fan 15 through exhaust wells 14.

Thus, the implementation of a new technical solution for underground mining has been performed for three technological schemes with various complexes of tunneling equipment, but with the obligatory presence of LTU. That is, the essence and effectiveness of the recommended technical solution is disclosed as a result of comparing the technical and economic indicators of the three proposed options and choosing the best of them according to the economic criterion.

An example of a specific implementation of the claimed technical solution.

The initial data for the calculations are as follows:

- the depth of the buried placer, N _p = 50 m;

- the slope of the inclined trunk, α = 4 °;

- the cost of a laser technological installation with a capacity of 10 kW, C _lu = 300 thousand dollars;

- the width of the double-track car trunk, W _st = 18.5 m;

- the average height of the trunk, h _article = 4.5 m;

- the length of the horizontal underground excavation L _pv = 70 m

The calculations are performed in the following sequence.

1. The volume of work on the excavation of underground workings:

- the cross-sectional area of the trunk S _article,

- barrel length L _article

- the volume of work on the sinking of the inclined shaft V _article

- the volume of work on driving a horizontal underground mine V _pv ,

then

- the total volume of underground workings V _p

2. Calculation of the costs of driving underground workings using a laser technological installation.

A 10 kW laser processing unit is powered by an electric drive.

Due to the lack of sufficient information on laser technologies and their application in the mining industry, some indicators in the calculations are based on expert estimates.

a). The cost of sinking underground excavations W _PV

where Z _article - the costs of sinking the inclined shaft, dollars;

Z _pv - the cost of sinking horizontal underground excavation, dollars

where C _pv - the cost of developing 1 m ³ of rocks by underground method, dollars / m ³ (Spv = 10.2 dollars / m ³ , see RU No. 2661769, publ. 07.20.2018).

b) The cost of mining mining equipment for the development of buried placer,

Complex 1: LTU - loader - bunker farm - dump truck;

Complex 2: LTU - loader - conveyor lift - belt feeder - dump truck;

Complex 3: LTU - stock picker - dump truck - dump truck.

Cost indicators of mining equipment:

LTU = 300 thousand dollars; loader = 40 thousand dollars; bunkering = 10 thousand dollars; dump truck = 120 thousand dollars; harvesting machine = 50 thousand dollars; conveyor lift = 150 thousand dollars; belt feeder = 10 thousand dollars

The number of dump trucks in all the considered variants is mostly the same, therefore they are excluded from the calculations.

Then, the cost of acquiring mining equipment for the formation of these types of complexes will be:

Complex 1:

Zpr1 = 300 + 40 +10 +120 = 470 thousand dollars;

Complex 2:

Zpr2 = 300 + 40 + 150 +10 +120 = 620 thousand dollars;

Complex 3:

Zpr3 = 300 + 50 + 120 + 120 = 590 thousand dollars.

From the calculations made it follows that the most advantageous solution when developing a buried placer is to use a complex of equipment as part of a pilot plant - a loader - a bunker farm - a dump truck. At the same time, it should be noted that with an increase in mining of the buried placer, the situation may change.

Thus, for the calculations of a comparative assessment of the effectiveness of the implementation of the recommended technical solution, an open method was adopted as a traditional option for working out the buried placer.

A. Traditional technology.

With the open-cast mining of buried placers, a certain amount of overburden work is required to be performed with V _vsk with the detachment of the quarry sides at traditional angles of 55 °. The contours of the quarry in waste form are shown in FIG. 4A. With the dimensions of the buried placer equal to 1000 × 500 m, the thickness of the ore body is 3 m, the volumes of mining and overburden V _vsk and additional volumes V _add to create normal working sites for mining the buried placer can be found:

where m is the thickness of the ore body, m = 3 m,

where W _RP - the normal width of the working platform, W _RP = 60 m,

Hence, the total production volume of stripping operations V _VSG for the excavation of buried placers,

Total costs of testing of buried deposits of conventional open-pit Z _OS is,

where C _OS - the cost of developing 1 m3 of rock in an open way, dollars / m3 (average cost for AK ALROSA, see RU No. 2233982, published on 08/10/2004).

B. Recommended technology (see Fig. 4B).

The cost of mining the buried placer by the recommended method Z _pc will be:

where Z _ps - the cost of mining the reserves of the buried placer by the underground method, dollars

Thus, the expected economic effect of the implementation of the new technical solution e will be equal to

The table shows the expected technical and economic indicators from the implementation of a new technical solution. From the results of the calculations of technical and economic efficiency from the implementation of a new technical solution, a significant improvement of the main development indicators follows. According to preliminary estimates, the expected economic effect amounted to $ 55.4 million.

An additional effect will be provided by improving the environmental situation in the mining region, which, according to expert estimates, ranges from a 2 to 5-fold reduction in the technogenic press on the environment.

Table

Expected technical and economic indicators from the implementation of a new technical solution

No. p / p The name of indicators Technology Traditional Recommended one Depth of buried placer mining, m fifty fifty 2 The volume of work on the excavation of underground workings for mining the buried placer, m3 - 66360,0 3 Placer parameters: length, width, power, m 1000 × 500 × 3 1000 × 500 × 3 four Scope of overburden operations for excavation of a buried placer with a slope angle of 55 °, million m3 20.8 - five The cost of mining the buried placer in an open way, mln. 70.8 - 6 The cost of mining the buried placer in the recommended manner, mln. 15.4 7 The economic effect of the implementation of a new technical solution, million dollars - 55,4 eight Decrease in technogenic press on the environment according to expert assessment, multiplicity - 2 ÷ 5 times

Claims (1)

A method for driving inclined shafts and horizontal underground workings under conditions of cryolithozone, including the use of non-explosive technologies for the destruction of a rock mass, their selective excavation, fastening workings with a mechanized complex and transporting rock mass, characterized in that the shafts and underground workings are carried out using a laser technological installation, the working bottom is treated with a laser beam from its center, for which, first, create a cylindrical hole up to 1 m deep, which they are expanding steadily, giving it a conical configuration by processing with a laser beam, forming a continuous process of deepening and expanding the funnel-shaped cavity in the plane of the face to the final contour of the face plane, and mining through the kimberlites using a laser beam is carried out by narrow cuts, eliminating the formation of mechanical stresses in the developed kimberlite massif and maintaining the integrity of the diamonds contained in it.

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