RU2778118C1 - Method for underground hydraulic mining of minerals and a device for its implementation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: inventions group relates to mining and can be used in the development of mineral deposits by the method for borehole hydraulic mining. The method for hydraulic mining of minerals includes opening a productive formation with production and auxiliary wells, placing a device for underground hydraulic mining in production wells, washing out the roof rocks above the productive formation until a cavity is formed in the form of a natural equilibrium arch, reinforcing and filling this cavity with a hardening mixture to create an artificial roof, forming in the productive formation of an inclined artificial bottom in the form of an inverted cone with a taper angle exceeding the angle of repose of the broken rock mass, erosion of the productive formation from the bottom up, periodic cleaning of the artificial bottom and lifting of the broken rock mass to the surface, subsequent backfilling of the mining chamber in the hydraulic fracturing mode through auxiliary wells . At the same time, before the start of erosion, compressed air is supplied to the production chamber and the air is displaced from the bottomhole. Scouring is carried out by a device for underground hydraulic mining with a rotary hydraulic monitor, and due to air pressure, before and during breaking, the water level in the chamber is maintained above the broken rock mass store, but below the outlet of the nozzle of the hydraulic monitor. The performance of the lifting device is controlled by changing the air pressure in the mining chamber. Erosion is carried out in layers, the thickness of which is chosen from the condition of their destruction when falling on the surface of the mass filling the bottom.

EFFECT: creation of a chamber of a given configuration, bringing the performance of the lifting device into conformity with the state of the bottomhole and the productivity of washout, and increasing the reliability of the operation of the device for underground hydraulic mining.

3 cl, 4 dwg

Description

The invention relates to mining and can be used in the development of mineral deposits by the method of borehole hydraulic mining. The use of this technical solution is especially advisable for the development of deposits, represented by ore bodies of stratal, lenticular, nesting, etc. forms covered by unstable rocks. Such deposits include, for example, peat deposits, sapropel deposits, sand and gravel deposits, coal, oil shale. In addition, this form of occurrence is typical for uranium roll deposits.

A known method of underground hydraulic mining of minerals, including the opening of a productive formation with production and auxiliary wells, placement of devices for downhole hydraulic production in production wells, erosion of the roof rocks over the productive formation with the formation of a cavity in the form of a set of natural equilibrium, reinforcement and filling this cavity with a hardening mixture to create an artificial roof formation, formation of an inclined artificial bottom in the form of an inverted cone with a taper angle exceeding the angle of repose of the broken rock mass, erosion of the productive formation from the bottom up, periodic cleaning of the artificial bottom and lifting of the broken rock mass, subsequent backfilling of the mining chamber with a hardening mixture in the hydraulic fracturing mode through auxiliary wells (see RF patent No. 2107165, class MKI 6 E21C 45/00, 1997).

This method allows you to work out productive formations covered by unstable overburden. But the implementation of this method is complicated by the need to create an inclined bottom, which is technically difficult to perform with conventional downhole monitors, as well as the need to periodically change the zenith angle of the liquid jet from horizontal, when the chamber array is washed out, to an inclined one, when cleaning the bottom. In addition, this method does not allow you to quickly adjust the state of the bottomhole space and bring it into line with the productivity of the washout, the performance of the lifting device, which negatively affects the efficiency of the field development.

A device for underground hydroextraction of useful materials is known, including a high-pressure feed string, a rotary monitor with a barrel, a nozzle and a knee, a latch, a hinge with a cavity, hydraulically connecting the monitor and a high-pressure feed string, and a slurry-dispensing column (USSR author's certificate No. 1095014, class MKI 6 E21C 45/00, 1983).

This device does not allow air to be supplied to the bottomhole space, in addition, when the hydraulic monitor is turned in a vertical plane, frequent breakdowns occur due to the fact that the barrel rests against the uncollapsed roof of the initial chamber and jams, breaks, etc.

The problem to be solved by the present invention is to increase the efficiency of mining of mineral deposits.

The technical result achieved as a result of using the invention is to ensure the creation of a chamber of a given configuration, matching the performance of the lifting device with the state of the face and the productivity of the washout, and increasing the reliability of the device for underground hydraulic mining.

The technical result is achieved by the fact that in the method of hydraulic mining of minerals, including the opening of the productive formation with production and auxiliary wells, the placement of a device for underground hydraulic mining in the production wells, the erosion of the roof rocks above the productive formation until a cavity is formed in the form of a natural equilibrium arch, reinforcement and filling of this cavity hardening mixture to create an artificial roof, formation of an inclined artificial bottom in the productive formation in the form of an inverted cone with a taper angle exceeding the angle of repose of the broken rock mass, erosion of the productive formation from the bottom up, periodic cleaning of the artificial bottom and lifting the broken rock mass to the surface, subsequent backfilling of the production chamber in the hydraulic fracturing mode through auxiliary wells, characterized in that before the start of the erosion of the productive formation, compressed air is supplied to the production chamber and water is displaced from the bottomhole, the erosion is carried out by a device for underground hydraulic mining with a rotary hydraulic monitor, and due to air pressure, before and during breaking, the water level in the chamber is maintained above the broken rock mass store, but below the outlet of the nozzle of the hydraulic monitor, while the performance of the lifting device is regulated by changing the air pressure in the mining chamber, Erosion is carried out in layers, the thickness of which is chosen from the condition of their destruction when falling on the surface of the mass filling the bottom.

The thickness of the layers is determined from the ratio

where h is the thickness of the eroded layer, m;

H is the distance from the eroded layer to the surface of the mass filling the bottom, m;

K - coefficient characterizing the strength of the rock mass;

k is a coefficient characterizing the surface of the material filling the bottom.

The method is carried out by a device for underground hydraulic mining of minerals, including a high-pressure supply line for liquid, a rotary hydraulic monitor with a shaft, a nozzle and a knee, a latch, a hinge with a cavity, hydraulically connecting the hydraulic monitor and a high-pressure supply line, a lifting unit with a slurry-dispensing column, characterized in that the device is equipped with a compressed air pipeline, the nozzle and the barrel are made removable, the barrel is made of a flexible elastic material, and the high-pressure supply line for the liquid and the compressed air pipeline are located inside the pulp-dispensing column and contact with it and between themselves with their walls.

In addition, the device is equipped with a spring-loaded probe and a hydraulic monitor rotation limiter, which are fixed on the surface of the pulp-dispensing column, while the rotation limiter is pivotally fixed above the hydraulic monitor, and the probe is made of adjustable length and is movably fixed in the guide housing.

The specified totality includes all the essential features, each of which is necessary, and all together are sufficient to achieve the specified technical result.

The invention is illustrated by drawings, where

in fig. 1 shows the general scheme of testing the camera;

in fig. 2 - device for underground hydraulic mining;

in fig. 3 - section along A-A;

in fig. 4 - view 1.

The method is carried out as follows.

A production well 1 and auxiliary wells 2 and 3 are drilled from the surface of the deposit. A production well 1 and auxiliary wells 2 are drilled to the boundary of the overburden 4 and the productive formation 5. A device for underground hydraulic mining of minerals 6 is placed in the production well 1 and the overburden 4 is washed out. on the border with the productive formation 5. In the process of erosion of the overburden 4 above the productive formation 5, a cavity 7 is formed, bounded by the surface of the arch of natural equilibrium.

After the formation of cavities 7 in overburden 4, in auxiliary wells 2 and cavities 7 through wells 2, metal reinforcement 9 is mounted, the upper ends of which are fixed to the surface. Then, a hardening solution is supplied to the cavity 7 through auxiliary wells 2 until the volume of the cavity 7 is completely filled with it. The hardening solution is supplied until its level exceeds the upper boundary of the surface of the arch of natural equilibrium. After hardening of the hardening solution, a stable artificial roof is formed.

The stable artificial roof formed in this way reliably isolates the covering rocks 4 located above the roof from falling on the bottom 10 of the mining chamber 11.

After the formation of an artificial roof, the production well 1 is passed to the soil of the productive formation.

A device for underground hydraulic mining of minerals 6 with a supply line 12, a slurry column 13, a compressed air pipeline 14 and a rotary hydraulic monitor with a shaft 15, a nozzle 16 and an elbow 17, is lowered to the bottom of the well 1 and the erosion of the productive formation 5 begins. the mining chamber 11 form an inclined bottom 10 in the form of an inverted cone with a taper angle exceeding the angle of repose of broken rock mass. The formation of the inclined bottom 10 guarantees the unconditional hit of the broken mineral in its lower part, i.e. to the bottom of the well.

Before the washout begins, compressed air is supplied to the production chamber and water is displaced from the bottomhole, ensuring the operation of the hydromonitor in a “dry” (relatively drained) bottomhole. Erosion of the productive formation 5 is carried out within the boundaries of the mining chamber 11. Breaking is carried out from the bottom up with periodic descent of the device for underground hydraulic mining of minerals 6 to the bottom of the well 1, where all the broken rock mass accumulates, which, through the lifting unit and the slurry column 13, due to the excess pressure in the mining chamber 11 is issued to the surface. Since the angle of the inclined bottom 10 exceeds the angle of repose of the broken rock mass, the entire eroded rock mass accumulates at the bottom of the production well 1 and, as the next descent of the device for underground hydraulic mining of minerals 6, by gravity, under the action of gravity, enters the lifting unit . This eliminates losses on the soil of the mining chamber 11.

Before and during the washout, compressed air is supplied to the chamber cavity and such excess pressure is created at which the liquid level is above the broken rock mass store, but below the outlet of the nozzle of the hydromonitor. In this way, work is achieved in a dry face and, at the same time, partial disintegration of the rock mass due to soaking. By changing the air pressure (but observing the indicated restrictions), it is possible to regulate the performance of the lifting unit and the pulp dispensing column. With increasing pressure, productivity increases and the possibility of blocking the face with destroyed rock mass is excluded.

Erosion is carried out in layers, the thickness of which is chosen from the condition of their destruction when falling on the surface of the mass filling the bottom, and is determined from the ratio

where h is the thickness of the eroded layer, m;

H is the distance from the eroded layer to the surface of the mass filling the bottom, m;

K - coefficient characterizing the strength of the rock mass;

k is a coefficient characterizing the surface of the material filling the bottom.

The coefficients are determined empirically.

For laying the production chamber 11, the hardening mixture is fed into the auxiliary wells 3 in the hydraulic fracturing mode. The hydraulic fracturing channels, extending from the auxiliary wells 3, will be directed towards the goaf of the production chamber 11, because after the formation of the mined-out space of the mining chamber 11, the redistribution of stresses caused by rock pressure will occur, with a decrease in their values towards the mining chamber 11. Through the formed hydraulic fracturing channels, the hardening mixture enters the mining chamber 11 and fills it. During the operation of laying the mining chamber 11, a device for underground hydraulic mining of minerals 6 is dismantled from the well 1.

The method is carried out by a device for underground hydraulic mining.

The device includes a high-pressure supply line 12, a pulp-dispensing column 13, a compressed air pipeline 14, a rotary hydraulic monitor with a barrel 15, a nozzle 16 and a knee 17. In addition, a hinge 18 spring-loaded by a spring 19, a sliding probe 20 movably fixed in the housing 21 and a rotation limiter 22, fixed on the axis 23. The probe is made of adjustable length (for example, two or three sections, with the possibility of fixing the sections relative to each other). Steps are made on the outer surface of the turn limiter to change the angle of rotation of the hydraulic monitor.

The device works as follows.

The device is lowered into the well 1, the bottomhole part of the well is isolated with a packer (not shown in the drawing), compressed air is injected through the compressed air pipeline 14 into the washout zone, displacing water and draining the bottomhole. Then liquid is fed into the monitor through the supply line 12 and the pulp-dispensing column 13, the compressed air pipeline 14 and the supply line 12 are rotated. carries out the erosion of the rock. Since the longitudinal axis of the barrel 15 of the monitor is displaced relative to the axis of rotation of the hinge 18 and forms a shoulder, the reactive force of the jet flowing from the nozzle 16 forms a torque that tends to turn the barrel 15 of the monitor in a vertical plane. Since the barrel 15 of the monitor is made of a flexible elastic material, when it hits the walls of the chamber being worked out or pieces of collapsing rock fall on it, it bends, which prevents it from breaking. The implementation of the shaft 15 and nozzle 16 is removable, allows you to quickly respond to changing washout conditions, use nozzles with different nozzle configurations, increase or decrease, depending on the size of the goaf, the length of the shaft, etc.

Placement of the supply stave 12 and the compressed air pipeline 14 in contact with each other and the wall of the slurry column 13 provides the maximum flow area of the latter, which allows you to lift, ceteris paribus, pieces of the largest diameter.

To create an inclined bottom, clean it and change the direction of the jet of the jet, the device is equipped with a probe 20 located in the guide housing 21, and a rotation limiter 22. The rotation limiter 22 is fixed on the axle 23. On the one hand, the rotation limiter 22 is in contact with the probe 20, and with the other with a water monitor. The surface (outer), along which it contacts with the probe 20, is made stepped to allow changing the fixation of the angle of inclination, moreover, the edges of the steps are made rounded.

When lowering the slurry column 13, the probe 20 abuts against the bottom of the well and moves in the guide housing 21 until the slurry column 13 also sinks to the bottom of the well (or is stopped at a predetermined distance from it). When moving, the probe 20 disengages from the rotation limiter 22. Due to the reactive force that occurs when a jet of liquid flows out of the nozzle 16, the monitor rotates around the hinge axis 18 and presses on the rotation limiter 22, which also rotates around the axis 23 until it stops in the probe 20 Due to the fact that the probe 20 is made sliding, it is possible to change the angle by which the monitor is rotated.

When lifting the pulp-extracting column 13, under the action of the spring 19, due to the fact that the ribs of the steps are rounded, the probe 20 returns to its original position, turns the rotation limiter 22, and that, in turn, the hydraulic monitor, the barrel 15 of which takes a horizontal position. Thus, an automatic change in the inclination of the hydromonitor is carried out from horizontal, during erosion, to the angle of repose, during the formation of the bottom and its cleaning, and vice versa.

The use of these methods and devices in the development of, above all, high-value ores, such as diamond-bearing kimberlites and primary gold deposits, ensures reliable extraction of the useful component from the mining chamber. In the case of insufficient stability of the side rocks of the chamber, the proposed technical solution allows you to quickly stop the erosion with simultaneous backfilling of the chamber's worked out part, restoring the stable state of the chamber walls and continuing to mine the upper part of the chamber without performing tripping operations of the mining projectile and maintaining its performance for the entire period of chamber mining. Also, the use of these methods and devices meets the requirements of environmental protection, especially when working in unstable host rocks.

Claims (3)

1. A method for hydraulic mining of minerals, including opening a productive formation with production and auxiliary wells, placing a device for underground hydraulic mining in production wells, washing out the roof rocks above the productive formation until a cavity is formed in the form of a natural equilibrium arch, reinforcing and filling this cavity with a hardening mixture to create an artificial roofs, formation of an inclined artificial bottom in the productive formation in the form of an inverted cone with a taper angle exceeding the angle of repose of the broken rock mass, erosion of the productive formation from the bottom up, periodic cleaning of the artificial bottom and lifting the broken rock mass to the surface, subsequent laying of the mining chamber in the hydraulic fracturing mode through auxiliary wells, characterized in that before the start of the washout, compressed air is supplied to the production chamber and the air is displaced from the bottomhole, the washout is carried out by a device for underground hydraulic mining with a rotary hydraulic monitor, and due to yes air pressure, before and during breaking, the water level in the chamber is maintained above the store of broken rock mass, but below the outlet of the nozzle of the hydraulic monitor, while the performance of the lifting device is regulated by changing the air pressure in the mining chamber, erosion is carried out in layers, the thickness of which is selected from the condition their destruction when falling on the surface of the mass filling the bottom. 2. A device for underground hydraulic mining of minerals, including a high-pressure supply line for liquid, a rotary hydraulic monitor with a shaft, a nozzle and a knee, a latch, a hinge with a cavity, hydraulically connecting the hydraulic monitor and a high-pressure supply line, a lifting unit with a slurry discharge column, the device is equipped with a compressed air pipeline , the nozzle and the barrel are made removable, the barrel is made of a flexible elastic material, and the high-pressure supply line for the liquid and the compressed air pipeline are located inside the pulp-dispensing column and contact with it and between themselves with their walls. 3. The device according to claim 2, characterized in that it is equipped with a spring-loaded probe and a hydraulic monitor rotation limiter, which are fixed on the surface of the pulp-dispensing column, while the rotation limiter is pivotally fixed above the hydraulic monitor, and the probe is made of adjustable length and is movably fixed in the guide housing.

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