SU1747699A1 - Method of stabilizing quicksand in open workings - Google Patents

Abstract

The invention relates to the mining industry and m. used in open cast mining of horizontal deposits. The goal is to increase the stability of the ledge and reduce water inflow into the working area during the subsequent mining of the ledge rocks. Along the ledge through stable overburden 3 and float 2 a row of vertical wells 4. Wells 4 charge explosives 6 in float 2 and explosives 5 to be released in covering rocks 3. The jumper is formed by blasting the indicated explosive charges. When blasting in floating 2, cavities are formed. These cavities are filled with cover rocks from an explosion explosion into the cavity. At the same time, explosive charges of explosive 5 are ejected with a deceleration relative to charges of WB 6 in flown 2, the indicated deceleration of the duration of the formation of cavities in the quill 2. The wells of the hole 4 in the row are drilled at a distance of different sum of the cavity diameter and the width of the compression zone 1 sf files, 3 Il.

Description

O.R.- .Ј „..- .. u r .....;. U; U. ..... o .-. °. e- ° .-. 6

. (Whig /

 -

FIELD OF THE INVENTION The invention relates to the mining industry, namely, to the technology of opencast mining of horizontal mineral deposits covered with overburden, including quicksand.

There is a known method for consolidating quicksand (silication). Liquid glass (sometimes with the addition of calcium chloride) is injected into the rock mass through the injectors driven into it. As a result of the physicochemical effect of injected agents with reinforced rock, a silica hydrogel is formed in it, which hardens and improves the stability, water resistance and strength of the rock. Clay rocks with a high content of fine particles and a low filtration coefficient have been proposed to strengthen with a multi-component lime mortar. In the rock mass, a series of wells are drilled, which are filled with a mixture of cement, lime and clay rocks. When this material interacts with reinforced rocks in the slope, piles are made of a material of higher strength than reinforced rocks that form around the wells of the zone of low humidity and increased strength. The methods outlined are costly. They do not allow the overburdening of ledges with flood inclusions, and therefore cannot be used in opencast mining of overburdened deposits, including flooding.

Nibis is closer to the proposed method of artificially freezing gbry rocks. The method consists in the fact that parallel to the slope of the ledge under development in the massif of quaff, its thickness creates an ice-ground barrier that protects the bottom from the penetration of water into it and strengthens the slope of the ledge. A low temperature for freezing the flosun is obtained by injecting refrigerating agents (ammonia, carbon dioxide, freon) into it. Along the contour of the ice-earth barrier, wells are pumped through the strata of aquifers into the wells, which are injected into the wells. As a result of cooling, cylinders of frozen rock are formed around the freezing columns, which increase over time and, finally, join together, forming a solid ice-ground fence.

The disadvantages of the method of freezing rocks in relation to open-cast mining are the difficulty of strengthening the overburden ledges (10-15 m high and

more) and significant costs for the creation of ice-ground fencing (1.5-2 m long). It is technically and technologically difficult to organize the freezing of the narrow floor 1 floating yards in parallel with the tapping. It is necessary to maintain the ice-ground barrier in the frozen state over the entire length of the ledge, which requires the creation of a huge freezing system.

The purpose of the invention is to increase the stability of the ledge and reduce water inflow into the working area during the subsequent mining of the ledge rocks. The proposed method of strengthening the quicksand is advisable to use when developing a ledge according to the non-transport scheme. More stable slopes of the ledges provide less re-excavated overburden, as a result of a decrease in water inflow, the loss and clogging of the mineral is reduced,

The goal is achieved by the fact that along the ledge, through stable overburden and fluvun, a drill of a number of vertical wells and in a quill forms a web. For this, the wells are charged with the charge of explosive (BB) in the quiver and the charge of the BB to be released into the overburden. The bridges are formed by blasting the indicated explosive charges with the formation of cavities in the quicksand and filling the latter with covering rocks from an explosion explosion into the cavity, and the explosive charges of the explosive discharge are decelerated relative to the charges of the explosive in swims The wells in a row are drilled at a distance equal to the sum of the cavity diameter and the width of the compression zone of the quicksand rocks between the cavities. This makes it possible to create a hydraulic jumper in a floating vessel for the first time in an explosive manner. The internal explosive charges in the body of the quicksand create cavities that are filled with a covering, more stable rock with the help of emission charges. As a result of compaction of ductile rocks with the energy of internal explosions, layers with increased strength parameters are formed around cavities. This method of strengthening the quicksand is a new efficient method. On the one hand, the quicksand is compacted in compression zones; on the other hand, it is reinforced by B cavities with overburden.

Figure 1 shows downhole charges; figure 2 - the formation of cavities, fig.Z - filling quicksand covering rock.

The method is used in the open development of a horizontal reservoir 1, in the roof of which lies water-saturated quicksand 2 The quicksand is covered with resistant rocks 3. The method involves drilling blasting wells 4, in which ejection charges 5 are placed, and internal charges 6. The method with the formation of cavities 7 and compression zones 8.

The quicksand is strengthened as follows.

First, vertical blastholes 4 are drilled in the ledge through the strata of overburden 3 and floating 2 (up to the roof of the ore formation 1). The wells are drilled in a row at a distance from each other, equal to the sum of the diameter of the cavity 7 and the width of the compression zone 8 The row of wells are arranged parallel to the slope of the step being developed, at some distance from the slope. The wells are then charged. At the top of the well, charge 5 is placed at the bottom, and internal charge 6 at the bottom. An explosive network is assembled. They include a moderator in the network, which must explode charges 5 and 6 at different times. The ejection charges in relation to the internal charges must detonate with a deceleration equal to the duration of the formation of cavities 7 in the flood sea. . Compression zones 8 are created between cavities in the thickness of the quicksand. In these zones, the initial porosity of the rock is reduced due to its compression and other structural changes occurring in the pore space under the action of shock and elastic waves, qualitatively changing

the structure of plastic rock, making it more monolithic and less permeable. The length of charges 5 is calculated on the basis of the condition of filling the cavities 7 with the rock-covering rock 3. When these charges are blown up, the stable rock is thrown into the mass of the quicksand, due to which the silt is compacted and strengthened. When blasting an entire row of wells, a water barrier is formed. It will prevent the influx of water into the working area, where the stripping and crushing equipment operates.

Claims (2)

1. A method for strengthening flowwater in open pit mining, including drilling along a step of a series of vertical wells through stable overburden and flow, and forming a jumper in a flow, characterized in that, in order to increase the stability of the step and reduce water inflow into the working area during the development of rocks of the ledge, the wells charge the explosive charge in the quiver and the explosive charge to be released in the overburden, and the formation of a jumper leads to the blasting of these explosive charges with the formation of cavities in the float and filling the last they cover the rocks from the explosion to eject into the cavity, while the explosive charges of explosives are released with a deceleration relative to the charges BB along the flow line, equal to the duration of the formation of cavities in the bottom line. 2. A method according to claim 1, characterized in that the wells in a row are drilled at a distance equal to the sum of the cavity diameter and the width -1 of the compression zone (UL 2.2 fig.Z