RU2320873C2 - Method for pit protection against underground water inflows - Google Patents

Abstract

FIELD: mining, particularly mining and pit protection against underground water inflow in the case of open-pit kimberlite pipe and other mineral deposits development in subpermafrost horizon.

SUBSTANCE: method involves discharging water initially contained in deposit section to be developed and precipitation water from said deposit section; drilling injection wells around kimberlite pipe perimeter and performing explosions through regular system from pit bottom to create joined subvertical annular and subhorizontal rock fissured zones which have uniform fissures; supplying plugging materials therein and creating joined solid watertight diaphragms shaped as integral cups.

EFFECT: possibility to create watertight diaphragm, which protects deposit section to be developed against underground water ingress.

Description

The invention relates to mining, in particular for protecting quarries from the influx of groundwater during open pit mining of kimberlite pipes and deposits of other minerals in the permafrost (aquifer) horizon.

There is a method of protecting quarries in these conditions, including drainage - pumping or drainage of groundwater entering the quarry with their direction through a system of pipes with pumps into open reservoirs or underground aquifers of deep occurrence [1]. Prototype.

The disadvantages of this method are:

the need to create a complex system of outlet pipes with pumps and wells for pumping water entering the quarry into deeper reservoir horizons directly below the field being developed or lifting water upwards with its subsequent transportation through pipes for discharge into open reservoirs, if possible for environmental reasons, or injections into deeper reservoir horizons at a distance from the field;

the need, often, to move huge volumes of water, measured in hundreds of thousands of cubic meters.

The technical task is to create a continuous waterproof anti-filtration curtain that protects the developed part of the field from further groundwater inflows and the drainage of the underground waters originally contained in it.

A method is proposed for protecting a part of a kimberlite pipe or other mineral deposits developed in the permafrost horizon from an underground water influx, including the drainage of initially contained water, including those coming from sediments, in a part of the water field planned for development, namely, that injection wells are drilled along the perimeter of the kimberlite pipe and, on a regular network, from the bottom of the quarry, they create explosions in them subvertical annular and subhorizontal contiguous zones high fracture rocks, homogeneous by this criterion, then fed therein through injection wells plugging materials and create continuous waterproof curtain, forming one piece cup-shaped.

Introduced in the claims is such an essential feature that, previously, injection wells are drilled along the kimberlite pipe’s perimeter and along a regular network from the bottom of the quarry, it allows subsequent explosions to create contiguous subvertical annular and horizontal zones of highly fractured rocks that are homogeneous by this feature.

Introduced in the claims is such an essential feature that into the zones of high fracture rocks created by the explosions, which are homogeneous by this feature, plugging materials are fed through injection wells under pressure, and after hardening, they get joined subvertical and subhorizontal continuous monolithic waterproof antifiltration curtains that form one unit the shape of a glass.

The method is as follows. To create a subvertical part of the anti-filtration curtain, wells are drilled around the perimeter of the kimberlite pipe, so that the entire part planned for development is protected from water inflow, and, through a regular network, for example, at the tops of squares or rectangles, from the bottom of the quarry, wells are drilled to the design depth, then by explosions they create, respectively, subvertical and subhorizontal zones of rocks of high fracture, uniform in this sign, joined and hydraulically connected. Further, through the same wells, if necessary reconstructed by repeated drilling, grouting materials are supplied into the high fracture zones under pressure, after hardening of which a continuous monolithic waterproof antifiltration curtain in the form of a glass is formed, inside which the developed part of the field is located. It is preferable to use plugging materials that are not susceptible to the damaging effects of aggressive groundwater and whose volume during solidification increases, which contributes to a better filling of the pore space. The distance between the wells is chosen so that during explosions in two neighboring wells between them a homogeneous zone of fractured rocks is created. The degree of homogeneity of the fractured zone prior to injection of the solution can be estimated using geophysical studies in wells, in particular, by measuring successively the resistance between the electrodes in two neighboring wells, which will be filled with water under the considered conditions. In areas with high resistance and, consequently, a relatively lower degree of rock destruction, explosions should be repeated to increase their fracturing. The presence of a hydraulic connection between the subhorizontal and subvertical zones of highly fractured rocks can be established by known methods: by feeding solutions with various indicators — salts, dyes, radioactive isotopes — into the well at the bottom of the quarry and controlling their entry into the wells along the perimeter of the quarry. The waters that were initially contained in the rock volume isolated by the anti-filter curtains and entering the quarry with precipitation are removed by known methods of drainage and / or drainage. This is also the case when developing parts of coal deposits, bauxite in karst cavities, and alluvial gold deposits found in aquifers, although often in the field of permafrost development they are limited to the development of minerals in the frozen state, leaving the whole between the mined part of the deposit and the permafrost (aquifer) .

The advantage of the proposed method is to create a reliable antifiltration curtain in the form of a glass that isolates the mined part of the field from the influx of groundwater.

The source of information

1. Mountain Encyclopedia, Volume 1. - M .: Publishing House. The Soviet Encyclopedia, 1984, see p.407.

Claims (1)

A method of protecting a part of a kimberlite pipe or other mineral deposits developed in the permafrost horizon from an underground water influx, including the drainage of initially contained water, including those coming with sediments, in a part of the water field planned for development, characterized in that perimeter injection wells are drilled kimberlite pipe and, on a regular network, from the bottom of the quarry, create explosions in them subvertical annular and subhorizontal contiguous zones of rocks of high t gussinesses, homogeneous by this feature, are then fed into them through injection wells grouting materials and create continuous waterproof anti-filter curtains, forming one in the form of a glass.