RU2477371C1 - Method of working-out backfilling in flooded potassium mine - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method of working-out backfilling in flooded potassium mine involves well drilling, preparation of pulp by mixing carrying liquid and solid particles, supply of pulp through wells to flooded working-outs, and backfilling of working-outs. Drilling of injection well and well for liquid pumping-out is performed from day surface to flooded working-out meant for backfilling. Carrying liquid for pulp preparation is taken from flooded backfilled working-out on the level of its soil through the nearest well of the drilled wells. After excess pressure appears on the mouth of the injection well, pulp is supplied continuously; total supply volume of pulp solid particles to the mine through the injection well does not exceed the volume of possible liquid filtration through a sinkhole formed during flooding of potassium mine.

EFFECT: invention allows reducing the deposition of ground surface above flooded mine owing to preventing probable leaching.

1 dwg

Description

The invention relates to the mining industry and can be used when laying the workings of planned or accidentally flooded mines.

There is a method of preventing flooding of potash mines and dangerous deformations of the earth's surface during breakthroughs into underground water mines, including drilling wells from the earth's surface to the chambers, feeding filling materials into the chambers through the wells (Pat. 2341658 RF. Method of preventing flooding of potash mines and dangerous deformations of the earth's surface during breakthroughs into underground water mines No. 2007123225/03; declared on 06/20/07; published on 06/20/08, bull. No. 17).

However, this method is time-consuming and requires certain costs for the preparation of pulp for laying cameras.

Closest to the proposed technical solution is a method of water filling of flooded underground voids, including filling flooded underground voids by pumping coarse dispersed hydraulic mixtures through wells from the surface (Gaidin AM Hydro-filling of flooded underground voids. / A.M. Gaidin. // Gorn.Zhurn. - 2011. - No. 2. - S.34-36).

The disadvantage of this method is that in the process of supplying slurry through the well, it is possible to plug the well with settled material.

The technical result of the invention is to reduce the subsidence of the earth's surface over a flooded mine by preventing the possible leaching of carnallite pillars.

The technical result is achieved by the fact that in the method of laying the workings in a flooded potash mine, including drilling wells, preparing pulp by mixing carrier fluid and solid particles, feeding the pulp through the wells into the flooded workings, laying the workings, drilling an injection well and wells for pumping liquid out from the day surface in the flooded mine, designed for laying, while the carrier fluid for the preparation of pulp is taken from the flooded mortar to work at the level of after the occurrence of excess pressure at the mouth of the injection well, the pulp is supplied continuously, and the total volume of pulp solid particles supplied to the mine through the injection well does not exceed the volume of possible fluid filtration through the funnel formed during the flooding of the potash mine.

The implementation of the method is considered on the example of the technological scheme for laying the workings of the carnallite layer of the accidentally flooded mine of the First Bereznikovsky potash mine.

At the time of the flooding of the mine, part of the carnallite workings turned out to be underdeveloped. After the flooding of the mine due to decomposition of carnallite and the formation of additional cavities under these workings, large subsidence of the earth's surface is expected. A decrease in subsidence can be achieved by re-laying the flooded workings.

The essence of the method is illustrated in the drawing, which shows a general diagram of the bookmark workings of a flooded mine.

The drawing indicates: 1 - injection well; 2 - well for pumping liquid; 3 - mortgaged production; 4 - dump truck; 5 - place of storage of the filling material; 6 - loader; 7 - mixer; 8 - pump; 9 - soil pump; 10 - sealant; 11 - pressure gauge; 12 - development; 13 - ventilation output, 14 - failure funnel.

The method is as follows.

On the earth's surface, over predefined sections of the bookmark, a pulp preparation unit is equipped. For this purpose, filling material is delivered to the storage location 5, for example, by a dump truck 4, from where the filling material is loaded into the mixer 7, into which a liquid is supplied, by a loader 6.

To carry out the laying work, two wells are drilled. One of them, for example, injection well 1, at the mouth of which a sealant 10 is installed, serves to supply filling pulp, and the other well 2 - for pumping liquid. The wells are drilled so that they fall into the pledged mine 3. The fluid pumped out using the submersible pump 8 from the well 2 is fed into the mixer 7 and used to prepare the filling pulp.

The bookmark is made as follows.

The resulting pulp from the mixer 7 with a soil pump 9 is pumped into the injection well 1.

The control of the bookmarking process is carried out according to the indicators of the manometer 11 located at the mouth of the injection well 1.

Under the pressure of the column of pulp in the well, the laying of the workings 3 and 12 is carried out, which are close to the injection well 1.

After the start of filing the filling material in the injection well 1, the pressure in it, according to the pressure gauge, is absent, and then, as the workings are laid, it increases until it becomes excessive.

To ensure the efficiency of filling operations and to exclude the possibility of blocking the well with the settled material in it after the occurrence of excessive pressure at the mouth of the injection well, the pulp is continuously supplied.

It should be noted that the pressure loss on the transportation of pulp in a flooded mine is expected to be greater than during normal laying due to the fact that the movement of the pulp along the laid workings 3 and 12 occurs in the form of a flooded stream. In this case, the liquid from the openings 12, when laying, enters the ventilation opening 13 and then to the failure funnel 14, through which excess liquid is filtered.

When the pressure in the well, recorded on the pressure gauge 11, becomes close to the pressure of the pump 8, the tab workings 3 and 12 stop.

A potash mine is a container with walls through which the liquid is not filtered, so when pulp is fed into a flooded potash mine, water will rise in a failure funnel 14 formed when the mine is flooded.

Since the roof of the flooded mine contains mineralized water, then when they rise, salinization of groundwater occurs. Therefore, with a large feed rate of pulp, water will flow out of the failed funnel 14 onto the earth's surface, which is unacceptable by environmental conditions.

To prevent salinization of groundwater, the hourly supply of solid in the mine is limited so that it does not exceed the volume of possible liquid filtration through a failure funnel in the range from cover salt to the level of fresh water or the corresponding level of saline water. If the supply of solid exceeds the possible filtration volume, then salinization of groundwater will occur.

Liquid sampling from the well for pumping liquid 2 must be carried out near the soil of the paved mine 3, which will ensure the maximum MgCl ₂ content in the liquid and exclude the possible leaching of pillars, such as carnallite, and therefore prevent the subsidence of the earth's surface.

The proposed method allows to reduce the cost of laying the chambers by using liquid from a flooded mine to prepare pulp and to reduce the subsidence of the earth's surface by preventing the possible leaching of carnallite pillars.

Claims (1)

A method of laying workings in a flooded potash mine, including drilling wells, preparing pulp by mixing carrier fluid and solid particles, feeding pulp through wells into the flooded workings, laying workings, characterized in that the drilling of the injection well and the well for pumping the liquid out from the surface to the flooded the development intended for laying, while the carrier fluid for the preparation of pulp is taken from the flooded laying production at the level of its soil through the nearest oburennyh wells feeding the pulp after the occurrence of an overpressure on the discharge wellhead is continuously produced, while the total solids feed pulp particles into the mine through the injection well is less than the possible volume of filtration liquid through the failed funnel, resulting in flooding of potash mines.