RU1777621C - Method for recovery of mineral deposits by leaching - Google Patents

Abstract

The invention relates to the mining industry and can be used in the development of minerals using the PV method. The goal is to reduce the loss of useful component and the consumption of leaching solutions. The trapezoidal decompression zone around the well filters is carried out by drilling horizontal slots, which form in the form of an ellipse, with the major axes directed towards adjacent wells in a row. Slots are drilled in ascending order from the soil of the ore bed, followed by the collapse of each rock layer between the overlying and underlying slots into the worked out space. Gaps are laid by natural segregation of ore fractions with the preservation of large ore fractions in them or by artificial filling material (sand), depending on the size of 3 s fractions of the ore body. p fl, 2 ill. Yo

Description

The invention relates to mining and can be used in the development of underground leaching of deposits represented by productive horizons, composed of weakly permeable interlayers lying in the thickness of well-permeable enclosing rocks.

A known method of developing mineral deposits by underground leaching in poorly permeable ores, including the formation of gaps by erosion of minerals within the productive horizon, filling the gaps with filter material, equipping the wells with filters with isolation from gangue by installing packers, feeding the leaching reagent to pump out the productive solution from pumping wells.

The disadvantage of this method is the low efficiency of its application in the development of poorly permeable ore layers lying in the thickness of well-permeable enclosing rocks, as well as significant residual acidity, low content of useful components in productive solutions and large losses of useful components in the bowels.

The closest to the invention in technical essence and the achieved results is a method of leaching ores through wells, including opening the productive horizon by injection and pumping wells, placement of hydro-mining equipment in them, forming VJ VI VI

Oh Yu

 With

the zone of decompression by sinking of vertical trapezoidal slots with a large base near the well. After each slot is drilled from the same hydraulic monitor, it is filled with filtering material (sand), and then the next gap is washed out and laid. Wells are equipped with filters with isolation from waste rock by installing packers, supplying leaching reagent to injection wells and pumping productive solution from pumping wells.

This method has a significant drawback: it does not allow the formation of a well-permeable section of the ore body well prepared for leaching, because erosion of the next vertical gap requires cleaning the wellbore to the lower base of the cracks, while the filling material (sand) is removed, and if the angle of the lower base of the trapezoidal gap is greater than the angle of repose of the filling material, then the latter is completely removed, and if less, then the backfill material is partially removed.

The result is the closure (collapse) of the walls of the vertical slit under the influence of mountain pressure, which causes a sharp deterioration in the filtration properties of the prepared section (permeability reduction). Later, when working solutions are supplied to it, the latter does not come into contact with the worked out massif completely, which causes under extraction beneficial component and its loss, increased consumption of leaching solutions and environmental pollution.

The aim of the invention is to reduce the loss of useful component and the flow rate of leaching solutions by ensuring the increased permeability of the leached section of the ore body during its entire working life.

The goal is achieved in that in the method of mining by underground leaching, which includes opening the productive horizon with pumping and injection wells, placing hydraulic production equipment in the wells, forming slots in the zone of increased permeability, having a trapezoid cross-section with a large base at the wells, tab its filtering material, equipment of wells with filters with isolation from the surrounding rocks by installing packers. feed

leaching reagent wells and pumping productive solution from pumping wells, a trapezoidal zone of increased permeability form in the form of a zone

decompression by horizontal slits, which form in the form of an ellipse, with large bases directed towards adjacent wells in a row, they are drilled in an ascending order from the soil of the ore formation, followed by the collapse of each layer of rock located between the overlying and underlying cavities erosion into the worked out space,

The power of successively eroded cavities (slots) is determined from the expression

GP2 ggi

Claims (3)

1.67 2qn mi -I.y , m where mi is the thickness of the left (collapsed) ore layer, m; Zqn is the distributed load of the left ore layer on the erosion cavity. kN / m; 2y - the specific gravity of leached ores, kN / m3, and the permissible height of the decompression zone, above which overconsolidation of rocks occurs, is determined from the expression N hollow Nlk + Nck 2 shopping center cr (o m where Nlk is the power of the zone of development of the reservoir, M Nick. - the height of the immediate roof, m; mi is the thickness of the left interlayers in the decompression zone, m; Kp (t) 1.7--0.51 ° 2 is the empirical coefficient of loosening of clay rocks; t is the time of mining the ore site, days. In the case of addition of the mined ore body section by large (more than 1 mm) and small (more than 0.25 mm) ore fractions carry out the natural laying of cavities (gaps) of erosion of segregation of ore fractions with preservation of large ore fractions in them, since they themselves act as bookmarks, and in the case of addition of the mined of the ore body portion with small fractions of ore to prevent adhesion of the walls of the slit, the slots are artificially filled with filtering material (sand). The supply of the reagent solution to the leach section through the trapezoidal zone of decompression by horizontal slots, in the form of an ellipse, with large axes directed towards adjacent wells in a row, allows to reduce the loss of useful component and the flow rate of leaching solutions, which increases the efficiency of the method of underground leaching in On the whole, since it is precisely such a shape and arrangement of erosion cavities in plan that make it possible to exclude the possibility of formation of stagnant zones during leaching by ensuring the same lenght of the streamlines of leaching solutions. This leads to a more even development of the ore mass. In the cross section, the slots forming the decompression zone of the ore mass are arranged horizontally. This prevents the filling of the filling material (sand) from the gap, which leads to the closure (collapse) of the walls of the gap under the influence of mountain pressure and a sharp deterioration in the filtration properties of the prepared section (decrease in permeability). From the condition that decompression should capture the ore bed and partially the roof rocks for the full development of the ore zone, we find Nrazupl. (Cr (1 - 1) + 2 Ш1 Nlk + Nnk, where is nrazupl. - permissible height of the decompression zone, when exceeded, re-compaction of the rocks occurs; Kp (t) 1.7 - 0.3t ° 2 empirical coefficient of loosening of clay rocks as a function of time; t is the time of mining the ore site, days; gtr - thickness of the left interlayers in the decompression zone, m; Nlk. power of the development zone (formation) m; NNK - the height of the roof itself, m. Where from Nlk + Nnk -Smu i 1 Kp (t) In FIG. 1 shows a diagram of an arrangement of a trapezoidal decompression zone with horizontal slits, a section; in FIG. 2 is a layout diagram of decompression zones, plan. The method is carried out as follows. 5 10 15 20 25 3Q 35 P 5 0 On the area of the reservoir, the contours of injection 1, pumping 2 wells and the future decompression zone with horizontal slots 4 are outlined. Productive horizon 3 is opened by injection wells 1a, 16, ... and pumping wells 2a, 26 .... From these wells, a trapezoidal decompression zone is formed by sinking horizontal slots 4 and collapsing of each rock layer 5 located between the overlying and underlying slots 4. To exclude the possibility of formation of stagnant zones by horizontal erosion cavities 4, forming the decompaction zone of the leached area, they are shaped into ellipses, with large axes directed towards adjacent wells in the row, formed naturally during erosion of the rocks by decreasing the rotation speed of the hydraulic monitor when approaching to the axis connecting the wells of the same name in a row. Such a shape of the leach zone decompression zone in plan provides the same length of the leach solution flow lines, which leads to a more uniform study of the ore mass by leach solutions, reduction of stagnant zones and component loss subsoil. The power of successively eroded slots 4 is set depending on the power of the remaining ore layers 5, the distributed load of the left ore layer 5 on the slot 4, the specific gravity of the leached ores, and the permissible height of the decompression zone is determined depending on the total thickness of the left interlayers b in the zone softening and loosening coefficient of clay rocks. Horizontal slots 4, forming the decompression zone, are laid by natural segregation of ore activities, with the preservation of large (+ 10-15 mm) fractions in them in the case of addition of the mined ore body section large (+ 10-15 mm) and small (less than 0.25 mm ) ore fractions, and in the absence of large (+ 10-15 mm) ore fractions, slots 4 are laid with artificially good filtering material (sand). Between the upper and lower boundaries of the decompression zone, a filter 7 is installed with packers 8 in the lower and upper parts of the ore gap, isolating it from the host rocks 6. After that, the underground leaching process is started. The leaching reagent under excess pressure created at the injection wells 1 penetrates through the permeable tab of the slots 4 into the trapezoidal decompression zone and moves to the decompression zones at the pumping wells 2, partly through the ore mass 3, and partly through the ore mass with access to well-permeable rocks b returning to the ore massif 3 to the decompression zone at the pumping wells 2, due to the created funnel of depression, ensuring uniform and complete exploration of the ore beds 3. The application of the present invention will improve the efficiency of the underground leaching method in the processing of poorly permeable ores lying in the thickness of well-permeable enclosing rocks. Formula 1. A method of extracting minerals by underground leaching, which includes opening the productive horizon by injection and pumping wells, placing hydro-mining equipment in the wells, and forming slots with an increased permeability zone having in section is a trapezoidal shape with a large base near the well, laying it with filter material, equipping the wells with filters with isolation from the enclosing rocks by installing packers, feeding leaching reagent to the injection wells and pumping productive solution and pumping wells, characterized in that, in order to reduce the loss of useful component and the flow rate of leaching solutions by ensuring the increased permeability of the leached section of the ore body during the entire time of its mining, the trapezoidal zone of increased permeability is formed in the form of a decompression zone with horizontal slots, which form in the form of ellipses, the major axes directed towards adjacent wells in a row, and their penetration is carried out in an ascending sequence from ore plazg soil with the subsequent collapse of each layer rocks located between the overlying and underlying erosion cavities in the worked out space. 2. The method according to claim 1, characterized in that the power of the subsequently eroded slots is determined from the expression SH2 PSHCH 1.67-2dp mi -2y m where mi is the thickness of the left (collapsing) ore layer, m; 20p - distributed load of the left ore layer on the erosion cavity, kNm;  - specific gravity of leached ores, kN / m3, and the permissible height of the decompression zone, when exceeded, the compaction of the rocks occurs, is determined from the expression: N hollow NLK + NNK - 2tk KrTO m where is Nlk. power of the development zone (plastga), m; Nick - the height of the immediate roof, m; mi is the thickness of the left interlayers in the decompression zone, m; Kp (t) 1.7-0.3 tO, 2 - empirical coefficient of loosening of clay rocks; t is the time of mining the ore site, days. 3. The method according to p. 1, characterized in that in the case of adding the mined section of the ore body with large (+ 10-15 mm) and small (less than 0.25 mm) ore fractions natural filling of slots is carried out by segregation of ore fractions with preservation of large ore fractions in them, which serve as bookmarks. 4, The method according to claim 1, characterized in that in the case of addition of the ore body section with small (less than 0.25 mm) ore fractions, artificial filling of the gaps is carried out with filtering material (sand). NNK. N layer Nl.K. -% l.i