WO2013105881A2

WO2013105881A2 - Method for constructing an injection system for developing the non-water-saturated part of an ore body during subterranean leaching

Info

Publication number: WO2013105881A2
Application number: PCT/RU2013/000004
Authority: WO
Inventors: Геннадий Сергеевич ГРЕБНЕВ; Николай Васильевич САВЕНЯ; Михаил Николаевич САВЕНЯ; Константин Александрович ЗАБОЛОЦКИЙ
Original assignee: Общество С Ограниченной Ответственностью "Уральская Геотехнологическая Компания"
Priority date: 2012-01-11
Filing date: 2013-01-09
Publication date: 2013-07-18
Also published as: EA201300066A1; WO2013105881A3; RU2012100893A

Abstract

The method for constructing an injection system for developing the non-water-saturated part of an ore body during subterranean leaching relates to the field of mining and, more specifically, to geotechnical mine development methods. The method consists in constructing injection openings and entails determining the largest water-bearing zone in the non-water-saturated part of an ore body at the hydrogeological and geophysical survey stage, said zone being situated, as a rule, below the covering deposits in the upper part of the non-water-saturated ore body, and opening the zone by means of injection openings. The injection openings are in the form of infiltration ditches or trenches or drains or injection wells, depending upon the thickness of the largest water-bearing zone, the location thereof and the thickness of the covering deposits. Using the proposed method makes it possible to increase extraction of the commercial component as a result of the inclusion of the non-water-saturated part of an ore body in the development process and the equal distribution of leaching solution, reduce injection system construction costs, and improve the environmental situation at the area of operations by reducing the number of injection openings and, as a result, the number of possible spills.

Description

METHOD FOR CONSTRUCTING A PURCHASING SYSTEM FOR TREATMENT OF AN IRRIGATED PART OF THE ORE BODY UNDER UNDERGROUND LEACHING

Technical field

The invention relates to mining, and in particular to geotechnological methods for mining deposits.

With geotechnological mining methods, the most important factor for successful development of a field is the permeability of the productive horizon during underground leaching. In addition, with underground leaching, the presence of partial or complete water cut of the ore and the confinement of ore mineralization to pores and cracks are important. It is known that during underground leaching, the geofiltration medium is characterized by heterogeneity both in plan and in section, especially in its non-irrigated part. Therefore, accounting, identifying and using these features can reduce costs in the construction of an injection system for working out the unified part of the ore body.

State of the art

Known methods for mining deposits having areas with a shallow bed of ores using infiltration channels built from the surface (A.I. Kalabin, "Extraction of minerals by underground leaching" M .: Atomizdat, 1969, pp. 240-245).

A known method of leaching underground deposits at the place of their formation (US US JY <3278233, IPC E21B43 / 28, 1966-10-1 1), according to which the fields are filled with water. Air is passed through a humidified field to remove water, and then served

DEPARTMENT OF YUSCHI YL YST (P EQUAL 26) acid gas to form an aqueous acidic solvent. Then water is fed into the deposit and the leached components are leached. The process is cyclically repeated.

The disadvantages of this method are the complexity and duration of the process.

A known method of mining using the dissolution process (US JY "4586752, IPC C22BZ / 06; C22B60 / 02; E21B43 / 28, publ. 1986-05-06), which is especially applicable for the development of deposits, at least partially covered with underground water The process is conducted in three stages: at the first stage, the leaching solution is injected and a production solution is discharged onto the surface; on the second, they carry out only the issuance of a production solution to the surface; on the third, they again start pumping the leach and pumping out the production solution.

The disadvantage of this method is that the implementation at the second stage of the process only issuance to the surface of the production solution leads to its dilution pulled by groundwater, which complicates the process of processing them.

There is a method of preparing technological solutions for underground leaching (RU JV2 21 1 1350, MPK6 21B43 / 28, publ. 05/20/1998), which consists in the fact that when located with an ore deposit or individual ore bodies of an anhydrous ore horizon, water is pumped through injection wells in anhydrous rocks, withstand it and send the solutions to the lower reservoir to be leached.

There is a method of underground leaching of metals from anhydrous ores (RU JY ^O 2126085, MPK6 E21B43 / 28, publ. 02/10/1999), in which anhydrous ore parts are pre-flooded to fill anhydrous reservoir-infiltration deposits through injection wells

SUBSTITUTE SHEET (RULE 26) horizon and after reaching the water level in the pumping wells corresponding to the provision of pumping, leaching solutions and pumping water from the pumping wells begin to be pumped into the pumping wells.

The disadvantage of these methods is the need to use an external source of water supply, the ability to draw water from it and the organization of measures to prevent the spreading of the solution into the anhydrous parts of the ore-bearing horizon. In addition, in the conditions of such deposits, it is problematic to maintain the balance of injection - pumping of solutions.

The closest in technical essence to the claimed method of constructing an injection system for working out the non-irrigated part of the ore body during underground leaching, adopted as a prototype, is a method of artificial replenishment of groundwater (SNiP 2.04.02-84 Guide for the design of facilities for groundwater abstraction, part 2, n. P), according to which facilities are provided for taking water from a source, its preliminary preparation, and actually the infiltration facilities (injection systems) through which they are supplied (inf ltratsiyu) water in the aquifer. As infiltration systems, pools (ponds), platforms, ditches, grooves are used, which are open infiltration structures that are used to replenish groundwater reserves of the first aquifer in the absence or low thickness of cover (alluvial) poorly permeable sediments, and in case of significant the power of such deposits is used by closed infiltration systems, which are used as tubular drains, galleries, adits, boreholes and mine wells. The use of open or closed infiltration systems is determined by the technical characteristics of the equipment used and the geological conditions at the place of work. Compulsory

SUBSTITUTE SHEET (RULE 26) The condition for the effective operation of such structures is the presence of a high geofiltration uniformity in the non-irrigated part of the horizon into which water is supplied from the replenishment source, both in plan and in section, and the absence of deposits that impede the infiltration movement of water in the roof of the aquifer.

Mineral deposits mined by underground leaching, especially for their non-irrigated parts, are characterized by geofiltration heterogeneity of the medium both in plan and in section, which can be used to reduce costs in the construction of injection systems in underground leaching processes.

Geofiltration heterogeneity is created during the weathering of various intermediate and final decomposition products of minerals and rocks, which can dissolve and be carried away by surface waters. Their migration is carried out in the form of mechanical suspensions, colloidal and true solutions, as a result of which zones with different filtration permeability are formed. The upper part of the deposit, which can subsequently be blocked by subsequent cover (alluvial) deposits, is usually subject to the greatest weathering.

Thus, layers of increased filtration capacity with a thickness of the order of a few meters in the upper part of the weathering crust, formed naturally as a result of chemical and physical weathering of rocks, fine fractions during crust formation and evolutionary weathering, can serve as a natural collector for feeding leaching solutions to the non-irrigated part of the ore body , and for the development of deposits having areas with a shallow ore bedding, with geotechnological methods of mining using calling infiltration channels, or trenches, or drains, or injection wells.

SUBSTITUTE SHEET (RULE 26) The disadvantages of this method include the low percentage of extraction of the natural component, significant costs for the construction of the injection system and poor environmental conditions due to the organization of a large number of injection workings, and, as a result, the number of possible spills. In addition, an open long-acting source of water should be located nearby, the selection of water from which will not harm the environment.

Disclosure of invention

The problem to which the invention is directed, is to develop a method for constructing an injection system for working out the non-irrigated part of the ore body during underground leaching.

The technical result of the proposed solution is to increase the degree of extraction of the useful component due to the involvement in the development of the non-irrigated part of the ore body, uniform distribution of the leaching solution, reducing the cost of constructing the injection system and improving the environmental situation at the place of work by reducing the number of injection workings and, as a result , the number of possible spills.

Distinctive features of the claimed technical solution from the closest analogue are:

- study of the filtration heterogeneity of the non-irrigated part of the ore body in the context and in the plan in the process of hydrogeological and geophysical surveys at the deposit and identifying the most conductive ore interval;

- the ability to supply a leach solution to the identified most water-spaced ore interval using infiltration ditches or trenches, or drains, or injection wells; at

SUBSTITUTE SHEET (RULE 26) this, the choice of a specific injection system depends on the size of the most water-spaced ore interval, its location and thickness of the overburden identified during geological surveys.

In this case, the flooded part of the ore body is opened as usual using injection and pumping openings.

To achieve a technical result, according to the method of constructing an injection system for working out the non-watered part of the ore body during underground leaching, including the construction of injection workings, according to the invention, in the non-water part of the ore body during hydrogeological and geophysical surveys, the most water-spaced interval is allocated, usually located under cover deposits in the upper part of the non-irrigated ore body, and open it with injection workings.

With this:

one . as injection workings, infiltration ditches or trenches, or drains, or injection wells are used;

2. infiltration ditches or trenches, or drains, or injection wells are constructed depending on the thickness of the identified most water-conducting interval, its location and the thickness of the overburden.

Brief Description of the Drawings

The implementation of the proposed method for the construction of an injection system for mining the non-irrigated part of the ore body during underground leaching is illustrated by the figures.

Figure 1 shows a diagram of the infiltration ditch;

in FIG. 2- shows a diagram of the infiltration well;

in FIG. 3 shows the location of the wells on the test cells.

SUBSTITUTE SHEET (RULE 26) The table shows the results of experimental fillings in the boreholes Ν ° Ν_> 1, 2, 3.

Diagram of the infiltration ditch (Fig. 1) includes: 1 - cover deposits; 2 - clay layer; 3 - zone of increased water conductivity; 4 - non-irrigated horizon; 5 - flooded horizon; 6 - injection manifold; 7 - a pipe; 8 - infiltration ditch; 9 - soil backfill; 10 - clay backfill; 1 1 - plastic film; 12 - filter material; 13 - spreading zone.

Scheme infiltration wells (Fig. 2) includes: 1 - cover deposits; 2 - clay layer; 3 - zone of increased water conductivity; 4 - non-irrigated horizon; 5 - flooded horizon; 12 - filter material; 13 - spreading zone; 14 is a well; 15 - casing with a filter; 16 - annular cementation.

The layout of the wells in the test cells (Fig. 3) includes: 1 - cover deposits; 2 - clay layer; 3 - zone of increased water conductivity; 4 - non-irrigated horizon; 5 - flooded horizon; 12 - filter material; 13 - spreading zone; 14 - well; 15 - casing with a filter; 16 - annular cementation.

The best embodiment of the invention

An obligatory stage of field development should be the conduct of hydrogeological studies by known methods, for example, during which the degree of water cut of the field and the possibility of its development by geotechnological methods are established.

In the presence of a non-irrigated part of the field involved in mining, hydrogeological and geophysical methods identify the zone of increased water conductivity in its upper part and, depending on the depth and thickness of the location, open it with infiltration

SUBSTITUTE SHEET (RULE 26) ditches, or trenches, or drains, or injection wells, and in the case of a zone of increased filterability to the surface, ponds are built.

Injection workings are constructed as follows (Fig. 1). With a small thickness of cover deposits, infiltration ditches 8 are constructed to open the identified zone of increased water conductivity 3, they are covered with filtering acid-resistant material 12, the filtration properties of which are higher than those of the identified most water-conducting interval, covered with plastic film 1 1, covered with clay 10 and backfill soil 9 and roll away. Leaching solutions are fed into the layer of filtering material through pipes 7 connected to the injection manifold 6.

With a large thickness of the overburden (Fig. 2), wells 14 are drilled, cased with pipes 15 with perforation in the lower part located in the zone of the revealed increased water conductivity 3.

Irrigation ponds are arranged in natural or artificial excavations on the surface of the ore body. The feasibility of their use is determined by the topography and properties of the leaching reagents.

The number of ditches, wells and ponds is selected from the condition of overlapping in terms of infiltration flows and the required irrigation density.

The proposed method has been tested in the field ^'during the hydrogeological works on the part neobvodnonnom field of silicate nickel ores.

The non-irrigated zone was located in the upper part of the ore body and is overlain by alluvial deposits with a thickness of 5-7 meters.

In the process of hydrogeological studies, the thicknesses of the non-irrigated part of the ore body and its upper, more permeable part were determined, which amounted, respectively, to 28-35 and 2-4 m.

SUBSTITUTE SHEET (RULE 26) To determine the productivity (injectivity) of the injection wells and the spreading area of the leach solutions, three cells with the same geological conditions were selected and three drilling holes with a diameter of 500 mm each were constructed respectively (Fig. 3).

A solution was supplied through the Ns l borehole to the upper, most permeable, non-irrigated part of the ore body, and through the J4b2 and N ° 3 boreholes, to the underlying non-watered parts located ten and twenty meters deeper, respectively.

In the course of the experiment, the injectivity of the boreholes, the spreading area of the solutions, and the time to reach the maximum spreading area of the solutions were determined. The spreading area of the solutions was determined by geophysical observations. The results are shown in the table.

As can be seen from this table, the injectivity and spreading area of the solutions along the N ° l borehole constructed in the upper part of the non-irrigated ore body is significantly higher than the similar values for the 2 and _ι_3 boreholes, which makes it possible to use a significantly smaller number of injection boreholes with the same volume of solutions injected into the ore body , and therefore reduce the cost of their construction and minimize environmental risks associated with accidents of the injection system. In addition, the uniform distribution of leaching solutions and the possibility of supplying them to the non-irrigated horizons of the ore body can increase the degree of extraction of useful components.

Thus, the above example shows the advantage of the proposed method of constructing an injection system for mining the non-irrigated part of the ore body during underground leaching over the known ones.

SUBSTITUTE SHEET (RULE 26) Table

SUBSTITUTE SHEET (RULE 26)

Claims

CLAIM

one . A method of constructing an injection system for working out the non-watered part of the ore body during underground leaching, including the construction of injection workings, characterized in that in the non-water part of the ore body during hydrogeological and geophysical surveys the most water-spaced interval is located, which is usually located under cover deposits in the upper part unhydrated ore body, and open it with injection workings.

2. The method according to p. 1, characterized in that as the injection workings, infiltration ditches or trenches, or drains, or injection wells are used.

3. The method according to p. 2, characterized in that the infiltration ditches or trenches, or drains, or injection wells are constructed depending on the capacity of the identified most water-conducting interval, its location and the thickness of the overburden.

SUBSTITUTE SHEET (RULE 26)