SU1726744A1 - Method of working ore deposits underground - Google Patents

Abstract

The invention relates to underground mining with the laying out of an explored space with hardening mixtures. The goal is to increase the efficiency of ore cleansing by reducing its losses and reducing the cost of building insulating bridges. Transport, haulage, ventilation and drilling workings pass through. The ore is continuously excavated by drilling and blasting wells in the chambers. The developed space is laid with a hardening mixture, first up to the top of the delivery development, then the rest of the chamber is laid after the previously laid bookmark has hardened. After that, a cut-off slot is formed on the contact of the ore-laying by blasting onto the unconsolidated laying of the ore of the first two rows of wells with deceleration when the laying reaches the maximum value of its viscosity index. The first from contact with the bookmark row of wells and the second from the first row of wells is drilled at a distance equal to half the line of least resistance. The time of slowing down the blasting of the second-row wells and the viscosity index of the backfill material are determined by the calculated formulas. 3 ill., 1 tab. WITH/

Description

The invention relates to mining and can be used in the development of mineral deposits by chamber mining systems with the laying of a goaf.

There is a method of underground mining of ore deposits, including carrying out loading and hauling and drilling workings, drilling and blasting wells, excavation of ore by chambers, laying the developed space hardening the mixture and the formation of a cutting gap after hardening the bookmark by drilling and blasting wells.

The disadvantage of this development method is the large amount of unproductive expenditures on excavation of wells and drilling of wells in a bookmark, depletion of ore with backfill material in the formation of a cutting slot in the tab and an increase in the period of working of the chambers caused by waiting for the time of hardening of the bookmarks for excavation of wells and drilling of wells. bookmark.

The closest to the present invention is a method of underground mining of ore deposits, including carrying out of transport, delivery, ventilation and drilling workings, drilling and blasting wells, continuous ore extraction by chambers, laying the worked out space hardening

Xi

GO

about

Xj

Ј

mixture, breaking the ore array on the uncured bookmark and release of ore.

In this method, the compensation space for loosening off the ore being recovered is compacted by a layer of unconsolidated plastic and elevated into the open space of the upper part of the chamber.

The disadvantage of this development method is the large ore losses due to its penetration into the uncured plastic bookmark at the time of breaking the ore mass and the cost of installing insulating bridges of the reinforced structure, since under these conditions a significant static pressure on the volume of the plastic bookmark of the embedded part of the chamber affects the bridge. as well as the danger of a possible breakthrough of the unhardened plastic tab from the chamber into the excavation

The aim of the invention is to increase the efficiency of ore cleansing by reducing the ore loss and reducing the cost of building insulating bridges.

This goal is achieved by the fact that, according to the method of underground mining of ore deposits, including carrying out transport, loading and storage, ventilation and drilling workings, drilling and blasting wells, continuous ore extraction by chambers, laying the developed space with a hardening mixture, breaking the ore body into uncured the laying and production of ore, the laying of the worked-out chamber space is carried out first up to the roof of the loading and hauling workings, then the filling of the worked-out space is solid after the hardening of the previously laid bookmark, the cutting mixture is made in the remaining part of the chamber, after which a cutting gap is formed at the contact of the ore-bookmark by blasting the ore of the first two rows of wells with deceleration when the bookmark reaches the maximum viscosity index. With laying a row of wells and the second row from the first row of wells, a distance of half the line of least resistance is drilled at a distance of half the line of least resistance, is determined from the expression (where ti is the deceleration of ani wells of the first row; T is the time for the separation of the ore layer by blasting the first row of wells); the viscosity index of the filling material is found using the VkGSJ formula. Kpl. ° comp. - the strength of the bookmark in compression; CL - coefficient of plasticity of the bookmark).

Blowing up a series of wells at the time of setting a bookmark to its maximum viscosity index B allows to seal the bookmark as much as possible and to form a compensation cavity at the ore-bookmark contact to loosen the ore being recovered in the chamber. At the same time, after hardening the bookmark, the ore does not penetrate into the bookmark, as a result of which its loss is reduced.

It is known that the strength properties of a bookmark are characterized by its compressive strength crc. and plastic properties - plasticity coefficient (where

Hey and Ed are the moduli of elasticity and total deformation, which characterize the fragile and deformational properties of the bookmark). Strength and plastic properties are interrelated with the viscosity index of the bookmark. Kpl.

By testing the sample bookmarks and calculations it was established that during the period of solidification

laying and achieving the maximum value of the indicator B shows the most rational combination of strength and plastic properties of the bookmark. At this point, the bookmark still achieves slight strength and brittleness, which characterize the destruction of the bookmark.

when exposed to a dynamic load (explosion), on the other hand, its plasticity is relatively high, contributing to podiizhku and compaction when acting on the tab

dynamic load.

The table shows the bookmark indicators for 60 days.

In the early days of hardening the bookmark, there is a rapid increase in its strength.

oj. decreasing by 8–10 days, and vice versa, its plastic properties of a KPL will sharply decrease by this period. At the time of a sharp decrease in Kpl, the maximum value of the indicator B is reached. It is during this period that it is necessary to blow up the wells in order to reduce the degree of destruction of the bookmark and at the same time achieve a large movement of the contact of the ore body with the bookmark.

During the drilling of wells, the chamber is hardened in two stages: I - voids from the soil level to the roof of the excavation, in which an insulating bridge is installed; II - the emptiness of the rest of the top

parts of the camera after setting the tab 1 queue. This allows the use of lightweight collapsible insulated jumpers and reduces the cost of their construction.

Blasting the first rows of wells with slower ti and t2 allows imposing the impact energy of the second-row broken layer of ore on the layer of ore of the first row of wells in the process of the explosion and thus enhancing the impact of the explosion on the bookmark, and therefore thicker it. This creates a positive effect of a single smooth load on the bookmark in the form of a piston effect, allowing to reduce the destructive effect of the explosion on the bookmark, but to a greater extent increase the displacement of the broken ore layers to create a compensation space and normal development of subsequent rows of wells.

If this condition is not observed, as is the case in practice with ordinary short-delay blasting, repeated shock loads occur and this positive effect is not achieved.

The deceleration time of electric detonators in wells of the first row is taken less, for example, instantaneous action, and the time of slowing down the wells of the next row is based on the calculations, it determines the time T depending on the value of W and the known propagation speeds of the shock wave Uud and the time of formation of cracks VTp in a well ore layer for specific physicomechanical properties of the ore massif:

 , t 9. W 1, W 1 I - I beats t Ttr - i -FT

W W VyA 2VTP

W (V.

one

+

Vyfl + 2 1

V

tr

UD

2 v

ms

tr

The determination of the value of T is based on the physical essence of the action of the explosion of explosives in a number of wells in the punching layer with a thickness equal to w / 2 in this case.

After the explosion of the explosive charge in the first row of wells, a shock wave is formed, which moves from the charge B to the downhole plane of the discarded layer, reflects from this plane and moves in the opposite direction, exhibiting a chipping effect. Shock wave action time

This is equal to 1 to 2: Uud W: Uud.

Under the action of a reflected shock wave in the layer, cracking occurs, the time of which is equal to tTp - -: VTp Then, under the influence of pressure of gases as a combustion product of explosives in charge, the layer of the first row of wells begins to separate from the ore massif, shock load

from the explosion of a layer of the second row of wells, i.e. through the summation of time T.T. and tTp, taking into account the deceleration time of electric detonators in the well of the first row. When blasting 5 wells of the first row with instantaneous detonators (m.) Time. The exploded first two rows of wells form a cutting slit with a width equal to W + Al and sufficient for the initial

10 of the volume of the compensation chamber space, where D1 is the amount of movement of the contact ore-bookmark, which according to research results is 0.3 and 0.5 W for wells with a diameter of 70 and 105 mm.

15 The distance of the first row of wells from contact with the bookmark and the second row of wells from the first row, equal to W / 2, allows to ensure the quality of ore crushing and to achieve the best separation from the ore

20 of the backfill massif, since it is known that at the contact of the ore massif with the clamping medium represented by collapsed rocks or bookmark, the quality of the ore crushing deteriorates due to the loss of the energy of the shock waves. In this case, the loss of broken ore is reduced ..

FIG. 1 shows a camera. In the stage of drilling the ore massif by explosive wells, a transverse section; in fig. 2

30 — camera in the stage of formation of a cutting slit by the explosion of the first two rows of wells at the contact of the ore-bookmark, cross section; in fig. 3 - the camera is in the stage of its complete breaking, cross section.

35 On the sub-floor in the next developed chamber 1. adjacent to the previously developed and embedded hardening mixture 2, chamber 3, from the drilling 4 and ventilation 5 workings, the ore massif is drilled

40 explosive wells 6. wherein, at the contact, the ore-bookmark 7 is drilled in two rows of wells 8 from W / 2 to cut the cutting gap Q. After the bookmark 2 has hardened in the adjacent chamber 8 to its maximum value

45 viscosity index B, when the tab acquires a rational combination of strength and plastic properties, i.e. sufficient compliance with a lesser degree of its destruction by blasting the first two rows of wells 8 with a deceleration of the first row and the second row form a cutting slot 9. The compensation space is formed due to the explosion of two wells and a compacted deposit 55 tab on the value of D |. After the ore is discharged from the slit, its width is W + D1, which is sufficient for loosening the ore that is subsequently beaten. The value of D | contributes to the imposition of a shock load of the explosion of the second row of wells on the ore layer of the first row of wells at the time of its separation from the ore array due to an increase in vol. 2 relative to c by an amount T equal to the time spent on the separation of the reservoir of the first row of wells.

The remaining reserves of the chamber 1. Beat the ore 10 with the help of loading and hauling machines along the delivery 11 and the transport 12 workings are delivered to the ore passes at the formed slot by explosive wells 6.

After complete production of the broken ore 10, chamber 1 is laid with a hardening mixture 2. At the same time, the spent space is laid down first to the top of the excavation workings 11, pre-installing pre-assembled insulating bridges 13 of a lightweight type. Then, after the laid bookmark has hardened, the remaining voids in the upper part of chamber 1 are filled. After these works are completed, the cleaning cavity cycle is repeated in the next chamber 14.

Example. The proposed method of underground mining of ore deposits used in the development of polymetallic deposits, represented by steeply dipping ore deposits of valuable ores with a capacity of 20-40 m in rocks of medium resistance. The site of the deposit was worked out by continuous sublevel chamber ore excavation with the laying of hardening mixtures and the use of self propelled equipment.

The main parameters of the excavation: the height of the floor is 60 m, the substage is 15 m, the width of the chambers is 10 m, the length of the chambers is 20-40 m, it is equal to the thickness of the ore deposit, the distance between the loading and tapping workings is 8-8.5 m. , borehole blasting and ore production in chambers were carried out according to the proposed method.

On the sub-floor in the next developed chamber 1, adjacent to the previously developed and installed hardening mixture 2, chamber 3 from the drilling 4 and ventilation 5 workings, the ore massif was drilled with LPS-3 drilling machines with a diameter of 105 mm, 2 The contact ore-bookmark 7 drilled two rows of wells 8 s, 1 m for cutting the cutting gap 9. The standard strength of the hardening mixture is 4.7-5 MPa at three months of age. The composition of the hardening mixture, kg / m3; Portland cement 400-220; final tailings of the processing plant 1370, water 400 l / m3.

On the 8-10th day after hardening of the bookmark 2 in the adjacent chamber 3 to the maximum viscosity index, 5-11.5 MPa in the chamber 1, two rows of wells 8 were blown up at the contact of the ore-bookmark and a cutting slit 9 was formed with a width of 2 , 7-2.8 m, moreover, the movement of the ore-laying contact plane was 0.4-0.5 m due to compaction of the hardening mixture 2 into the 0 adjacent chamber 3 by means of an explosion.

The viscosity index B was determined according to the calculation tables, which were compiled periodically according to the results of tests of the cubes supplied to the mine 5 of the backfill mixture for the required strength H.-di to determine the deformation characteristics of Ey and Unit.

The wells of the first p-type were blown up with a slowdown, 12 ms, the second p-yes –c 0, 12 + 4,, 37MC.

The regulation of the time for slowing the explosion of charges in the wells was carried out using an electric blasting device Impulse.

5 After the ore was released from the cutting gap 9, the remaining reserves of the chamber were repaired with 1 set of 6 s and 2 m. Repulsed ore 10 using Toro-200 PDM for delivery 1T (m2) and transport 0.12 (, 0 m2) mine workings delivered to bloc ore passes.

After complete production of the broken ore 10, chamber 1 was laid with a hardening mixture 2: first, the developed space was laid to the roof of the delivery workings 11, and pre-installed light-weight collapsible insulating bridges of metal spreader posts trimmed with boards. Then, after the laid bookmark was hardened, the remaining voids in the upper part of chamber 1 were filled. After completing these works, the cleaning excavation cycle was repeated in the next chamber 14. 5 Using the developed method of underground mining, compared with the prototype, it reduced the ore loss and reduced costs for the construction of insulating strings.

Claims (1)

Invention Formula The method of underground mining of ore deposits, including carrying out transport, loading and hauling, 5 ventilation and drilling workings, drilling and blasting wells, continuous extraction of ore by chambers, laying of the developed space with a hardening mixture, breaking the ore massif into an uncured laying and production of ore, about tl is Due to the fact that, in order to increase the efficiency of the clearing excavation by reducing its losses and reducing the cost of constructing insulating bridges, the spent space of the chambers is laid out first before the roof of the loading and hauling workings, then the spent space is filled with the hardening mixture after hardening the previously laid bookmark, after which they form a cutting gap on the ore-bookmark contact by blasting the ore of the first two rows of wells with a deceleration laying the maximum value of its index in s0 bones, while the first from contact with the bookmark row of wells and the second from the first row of wells is drilled at a distance equal to half the line of least resistance, the retardation time of the second row of wells is determined from the expression (where ti is the retardation of the wells of the first row; T is the time for the separation of the ore by blasting the first row of wells); the viscosity index of the filling material is found using the formula V .. Kpl (where sgcf is the strength of the bookmark on compression Kpl, the coefficient of plasticity of the bookmark). 15