EA039979B1 - METHOD FOR UNDERGROUND DEVELOPMENT OF MASSIVE METALLOGENIC DEPOSITS - Google Patents

Description

The invention relates to the development of metallogenic mineral deposits by an underground method.

There are many methods of underground mining of ore deposits [1], which, to a greater or lesser extent, allow achieving the required results: in terms of labor productivity and safety, mechanization of mining operations, in terms of completeness and purity of mining, and in terms of environmental impact. Each of them has a set of both positive and negative characteristics. The task of specialists is to choose the optimal one for a particular field. However, it is necessary to recognize a more productive way when a development method is created for specific conditions. This approach was used in the creation of the present invention.

Massive metallogenic deposits are often a combination of smaller constituent fragments, which differ significantly, sometimes by several times, or even by an order of magnitude, from each other in terms of their metal content. Therefore, the problem of finding the possibility of separate mining and separate processing of different grades of ore is relevant. Among the known there are no development methods that provide advanced selective extraction of high-grade ore and processing of the remaining volume of low-grade ore directly in the spent block using hydrometallurgy processes. The presence of such a development method will allow optimizing the technological process of extracting a useful component and expanding the range of economic maneuver during the development of the deposit.

To achieve this goal, a number of conditions must be met:

1. Possibility of layer-by-layer extraction of ore with a given withdrawal step;

2. Ensuring direct access of people and mechanisms to the bare area of the stope for testing, zoning and separate breaking of ore;

3. The use of mechanized haulage of ore from the stope to the shaft;

4. Possibility of warehousing (storage) of poor ore in the bowels in a space waterproofed from the enclosing mountain range.

5. Irrigation with chemical or bacterial solutions of the stored ore, collection of the saturated solution and its supply to the processing plant.

To fulfill the above conditions, the development method with loose backfill can be most easily adapted [2, 3]. Therefore, it is taken as a prototype.

The essence of this method is that the deposit, depicted in the form of a schematic vertical section in Fig. 1 are divided into steep layers with normal thickness a and slope angle α.

From the stope 1, the ore is excavated with bands 2 of thickness Ab in an inclined layer, moving from bottom to top, and the mined-out space is backfilled by laying backfill material on the bottom of the working with a layer 3 of thickness Ah. Thus, all inclined layers of the ore deposit are mined, i.e. there is a gross extraction of ore and its replacement with a backfill supplied from outside.

From a technical point of view, blasted ore can play the role of a backfill. This opens up the prospect of separating ore in the stope according to quality indicators. Higher-quality ore is first of all given out on the mountain, and lesser-quality ore is left in the bowels in the form of a bookmark for the period of block mining. After this period, poor ore can also be involved in processing by chemical or bacterial leaching directly in underground conditions.

In the development method proposed as the invention, the ore deposit is initially divided into excavation blocks (FIG. 2).

By analogy with the prototype, the block is divided into steep layers with normal power a and inclination angle α. The thickness of the layer is determined by the type of mining and transport equipment. The angle of inclination α must necessarily exceed the angle of repose of the blasted ore. The fulfillment of this condition will exclude the formation of voids between the formed array from the exploded ore and the whole massif.

The scheme of preparatory and cutting work is similar to the prototype.

The stope working is horizontal, with the exception of the cut-off sections, which are small in length. In cross section, it has the shape of a triangle. The lying side of the overlying ore layer acts as an inclined ceiling. If necessary, the ceiling can be fastened with a simple mobile support. The stope is represented by a subvertical wall of the stope.

There is no doubt that this method of development provides direct safe access to an extended face along its entire height. If this possibility is used for direct geological monitoring, then it is possible to classify each layer of the ore that is beaten off by quality indicators. The content of a useful component, the degree of oxidation of the ore, the strength of the ore and its other technological characteristics can act as quality indicators of the ore.

Theoretically, it is possible to provide separate mining of ore with a high degree of differentiation according to various indicators. However, in practice it is sufficient to restrict ourselves to dividing the ore into two parts, one of which is of high quality and can be processed without delay at the factory with

- 1 039979 obtaining an accelerated economic effect. Poor ore must be left in the bowels as a bookmark. Upon completion of mining operations in the block, it is subjected to leaching.

To do this, during mining, a waterproofing protection 2 (Fig. 3) is created at the bottom of the block, and an areal mortar receiver 3 is mounted there.

Breaking of ore in each technological cycle is carried out in stages. First of all, high-quality ore is beaten off and shipped. In the second stage, poor ore is beaten off, which is laid in a layer of a certain thickness on the bottom of the stope. If necessary, the ore is subjected to mechanical crushing and pelletizing directly in the stope. Thus, repeating the technological cycles many times, the inclined layer is worked out, then the next overlying layer, etc. until the block is complete. Irrigation system 5 is mounted in the workings extinguished in the upper limit position 4.

Upon completion of mining operations in the block, it is completely ready for leaching. To do this, ore is irrigated at the upper elevations of the block. The solution passes through an array of destroyed ore, is saturated with metal and enters the bottom solution receiver, from where it is pumped into an accumulation tank in the capital mining, then - according to the technological scheme of hydrometallurgy.

To speed up the leaching reaction, air (oxygen) is supplied to the destroyed massif through pipes 7, which are mounted in the stope, covered with ore and, gradually increasing, are removed to the extinguished workings.

Alternatively, the soaking process is carried out as an injection by means of wells drilled into the stocked ore from the mine workings.

Practical implementation

The implementation begins with the driving of a standard set of workings that provide access to the block being mined. With some variations, depending on the specific conditions, this set may include haulage and ventilation crosscuts, a spiral transport exit, vertical workings designed for ventilation, rock mass bypass, as well as other auxiliary workings.

Preparatory and threaded workings, as well as mining operations carried out directly in the block, are identical to the prototype and are detailed in [3].

The development of each inclined layer begins with the penetration of the threaded workings 1 (Fig. 3), the role of which is played by the development, which is essentially a stope at the bottom of the block. The working has a triangular cross section. This not quite traditional shape fits organically into a geometric model with inclined layers. In addition, the triangular shape of the cross-section gives additional stability to the working, and the inclined ceiling can be simply and technologically fastened with a mobile support, ensuring the safety of work in the stope.

Before the start of the cleaning process, a waterproofing jumper 2 is built in the cut working and a mortar receiver 3 is mounted in the form of perforated pipes, which are connected by a pipeline to the storage tank in the capital mining working. Perforated pipes are given a slight slope towards the main pipeline, which ensures the gravity flow of the solution to the pipeline. Similar measures are carried out during the development of each worked out inclined layer. Thus, by the end of the block mining, an areal mortar receiver will be built at its lower level.

Cleaning operations in the inclined layer begin with geological testing of the bottomhole and identification of zones with a high metal content. These zones are drilled and blasted first. The beaten off rich ore is shipped and issued to the mountain. The second stage drills the remaining areas of the stope. After blasting, the poor ore is laid in a layer on the bottom of the mine. If necessary, dictated by the leaching technology, the blasted ore is subjected to additional preparation directly in the stope by crushing and pelletizing. This operation ends the cleaning cycle. By repeated repetition of cycles, the entire inclined layer is worked out, then, similarly, the overlying layer, etc.

Broken ore acquires a larger volume due to loosening. It is possible to achieve the required volume balance, taking into account the loosening and shipment of high-quality ore, by additional shipment of low-grade ore, with one type of imbalance, or by delivering rock mass from outside, with another type of imbalance. It is most practical to initially maintain a balance by manipulating the volume of shipped ore.

In the upper part of the block, the workings 4 are stopped (repaid) in a predetermined limit position. The location of repaid workings at the same level is unacceptable, as this weakens the stability of the ceiling of the block. Therefore, the production of each subsequent layer is stopped lagging behind the production of the layer of the previous one. Thus, the workings are able to maintain their integrity for a long time, while the ceiling rests on the formed array of destroyed ore in the intervals between the workings.

In addition to solving the problem of maintaining the ceiling in a stable state, with such a scheme for the repayment of stopes, it becomes possible to compensate for the shrinkage of the bulk mass as a result of

- 2 039979 for its inevitable seal. This is done by adding material to the bottom of the extinguished working. Thus, the stability of the ceiling is ensured for a long period of time.

In extinguished workings, an irrigation system 5 is installed, by means of which a chemical or bacterial solution is sprayed over the upper area of the stored ore. The solution, flowing down through the array of destroyed ore, is enriched with metal and collected by solution receivers 3, from where it is fed through pipelines to the accumulation tank, and from it for further processing.

The supply of solution to the array of exploded ore can also be organized through wells drilled into this array from capital mining workings.

If the rate of the leaching process is significantly affected by the presence of air (oxygen), then it is fed into the destroyed massif through pipes 7, which are mounted in the stope in the course of mining, covered with ore and, gradually increasing, are removed to the extinguished workings.

During the production of mining operations, absolutely the entire surface of the mined block, including the side and bottom, alternately at different times in separate fragments falls into the zone of active operations with direct access to them for people and equipment. This provides an opportunity to objectively assess the integrity of the enclosing rock mass and, if necessary, to carry out waterproofing measures. Thus, the stored ore is in a waterproof container, which allows leaching in the mode of complete flooding of the ore with the possibility of active control of the saturation concentration. From a technological point of view, such a design and the process carried out in it can be interpreted as a multiply enlarged analogue of vat leaching. A large volume of ore allows longer leaching time without loss of productivity compared to batch processing of the same volume in small capacity vats. In turn, an increase in the time of exposure of the solution to the ore allows you to increase the size of its crushing.

Claims (5)

CLAIM 1. The method of underground mining of massive metallogenic deposits, which includes dividing the ore deposit into mining blocks, dividing each block into steep layers, mining the layers in ascending sequence, mining each layer from bottom to top with longwalls from the stope with a triangular cross-section with an inclined ceiling and a sub-vertical face plane, characterized in that a waterproofing bridge is constructed at the bottom of the cut working of each layer and mortar receivers are mounted, which, as a result of mining operations, are covered with destroyed ore, the mining cycle begins with geological monitoring of the mining face, zoning the face plane according to the quality indicators of the ore, ore breaking is carried out in two stages, first, high-quality ore is beaten off and shipped, then the ore remaining in the face is beaten off, the ore is laid in a layer on the bottom of the stope, ending with this operation the cycle of stope work, the cycles are repeated until p complete mining of the layer, gradually raising the stope to the ceiling of the block, where it is stopped in a predetermined position, and the development of each subsequent layer is stopped below the development of the previous layer, which provides support for the formed areal ceiling of the block on an array of blasted ore, irrigation devices are mounted in the stopped workings or bulk soaking of the ore with a chemical or bacterial solution, which, passing through the stored ore, is saturated with metal, after which it is collected in the solution receivers at the bottom of the block, from where it is sent to the place of further processing. 2. The method according to claim 1, characterized in that the broken ore is subjected to mechanical crushing before being placed on the sole. 3. The method according to claim 2, characterized in that after crushing the ore is pelletized. 4. The method according to claim 1, characterized in that the leaching solution is supplied to the array of destroyed ore through wells drilled from capital workings. 5. The method according to claim 1, characterized in that to speed up the leaching process, air (oxygen) is supplied to the destroyed ore massif through pipes that are mounted in the stope, covered with ore and, gradually increasing, are removed to the extinguished workings. - 3 039979 Vertical section perpendicular to the clearing working 1 - working development; 2 - layer of extracted ore; 3 - a layer of poured bookmarks. Fig. 1 Axonometry of the extraction block a - the angle of inclination of the working layer; m is the normal thickness of the layer. Fig. 2 - 4 039979 Vertical section of the mining block 1 - threaded workings: 2 - waterproofing jumper: 3 - mortar receivers: 4 - extinguished workings: 5 - sprinklers: 6 - ore stockpiled: 7- pipes for supplying air (oxygen)