RU2249697C1 - Method for open extraction of mineral resources deposits - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: method includes extraction of quarry to planned depth with use of quarry ore chutes with accumulating bunkers, cutting ore chutes with deepening of mining in quarry, crushing ore blocks and pieces from face from bunker walls by explosives, loading ore to railway vehicles, cutting and shutting upper portion of ore chutes at each level when mining approaches there is performed by division on beds and semi-shelves with charges in wells, providing for crushing of rock to needed dimensions and safety of mine walls, and further decrease of pieces size and increasing efficiency of ore chute operation by excluding ore suspension is achieved by use of crushing assembly in form of bowl with plate at base, working as anvil under layer of rock, from where ore mass is self-propelled to bunker, and from there by feeder is sent to crusher and further through intermediate conveyer to main conveyer.

EFFECT: higher efficiency.

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Description

The invention relates to the mining industry, to methods of open-cast mining using the workings of an open-underground complex - opencast mine. A method for open-cast mining of steeply dipping and inclined deposits involves mining the quarry to the design depth using opencast ore mines with accumulating bunkers, cutting ore mines as mining operations deepen in the quarry, crushing oversized materials and rock blocks from the dump from the bunker walls using explosives (explosives), loading ores in railway vehicles. When mining the quarry to the design depth, cutting and redeeming the upper part of ore passes at each horizon when mining approaches them is carried out by dividing into layers and sub-steps with charges in the wells, ensuring crushing of the rock to standard sizes and preservation of the production walls. A further reduction in the size of the pieces and an increase in the efficiency of the ore discharge by eliminating ore freezes is achieved by using a crushing unit in the form of a mortar bowl with a plate in the base, working as an anvil under a layer of rock, from which the ore mass flows by gravity into the bunker and from it is fed by the feeder to the crusher and further through the intermediate conveyor - to the main conveyor.

The method allows to increase the efficiency of the extraction of minerals by eliminating ore freezes in ore passages and the use of explosives on crushing oversized materials, the destructive effect of explosions on the walls of bunkers and the use of more economical conveyor transport, which increases the distribution area of the open method when developing mineral deposits.

The invention relates to the mining industry and can be used in the open development of steeply declining and inclined deposits.

There is a method of developing an inclined powerful apatite deposit in mountainous areas using open pit mines for transporting ore from upper horizons to the withdrawal adit horizon, where ore is transferred from bunkers by gravity to railway vehicles. As ore is mined in the quarry and the approach to mining, they are cut off by drilling and blasting the surrounding rock mass around the mouth of the ore pass, and the ore hoppers are expanded to allow the ore to move after compaction with shock loads on the bottom of the hatches into vehicles [Rzhevsky V.V., Arsentiev A.A., Anistratov Yu.I. and other quarry ore passes. M .: Subsoil. - 1969. - 208 p.].

The disadvantage of this method is that when cutting the upper part of the ore pass into one ledge due to the breakage of the array by cracks from previous explosions and weathering of rocks, large-sized pieces are formed that reach the hatch devices, and they are crushed by the use of explosives (BB), which is often the reason destruction and hatch devices themselves. When eliminating ore freezes formed under the action of shock compaction loads and its freezing, the walls of the bunkers and the ore passes themselves are destroyed, which reduces the efficiency of the method of extracting minerals as a result of interruptions in ore loading and violation of the rhythm of the processes in the factory.

The closest in technical essence and the achieved result is a method of developing minerals, including mining a quarry to design depth using quarry ore passes and cutting when approaching mining operations to the site of their location, the use of explosives to crush oversized and eliminate freezes, as well as the use of plates for obtaining pieces of standard sizes and loading them with the help of hatches into railway vehicles [Gushchin VV, Epimakhov Yu.A. Kozyrev A.A. et al. Deep ore passes. Apatity Tr. Kola Scientific Center. - 1997. - 195 p.].

The disadvantage of this method is that the cutting of the upper part of the ore passes as ore is mined when the horizons are lowered to the height of the ledge does not preclude the formation of oversized materials, and the use of plates to redistribute the energy of falling stones for crushing them did not find a technical solution, therefore, despite some positive properties of the method , it is also characterized by interruptions in ore loading associated with the elimination of ore freezes in ore passages, bunkers and manhole hopper devices using explosives, crushing oversized materials, and destruction walls of ore passes and bunker devices.

The aim of the invention is to increase the efficiency of the extraction of minerals in an open way by increasing the stability of the quarry and eliminating the destruction of the walls of bunkers and ore passages.

This goal is achieved by the fact that in the method of open-cast mining of steeply dipping and inclined deposits, which includes mining the quarry to the design depth using quarry ore passages with accumulating bunkers, cutting ore passages as mining operations deepen in the quarry, crushing oversized and rock blocks from the dump from the bunker walls from using explosives (BB), loading ore into railway vehicles, cutting and redeeming the upper part of ore passes at each horizon when mining operations approach them about uschestvlyayut division into layers and podustupy with the charges in the wells, providing the rock crushing conditioned to size and sound generation walls. A further reduction in the size of the pieces and an increase in the efficiency of ore discharge by eliminating ore freezes is achieved by using a crushing unit in the form of a bowl-mortar with a plate in the base, working as an anvil under a layer of rock, from which the ore mass flows by gravity into the hopper and from it is fed into the crusher by feeder and Further through the intermediate conveyor to the main conveyor.

Improving the efficiency of cutting and extinguishing ore passes by eliminating the formation of oversized materials is achieved by dividing the rock thickness by the ledge height into layers and sub-thicknesses of each according to the allocated block sizes according to the fracturing and disruption of the massif by previous explosions and weathering of the rocks. Following the selection of the location and drilling of wells in a ring pattern and the thickening of wells near the walls of the ore pass, charges are placed in the centers of the allocated blocks for crushing them to standard sized pieces. To exclude block cleavage and their fall into the bunker, the first rows of wells around the ore pass are shorter, and deep into the array they are increased with a small excess at the level of the layer being removed. The blasting of wells is carried out in sections with a slowdown, and the opposite sections relative to the ore pass are blown up simultaneously for additional crushing of the pieces and exclude their expansion. Thus, layer after layer is drilled, the rock explodes and is removed and by the end of the work an intact and stable array is created in the walls of the ore pass, and the rock, crushed to a conditional size, enters the hopper and then is shipped.

An increase in the efficiency of ore run operations by eliminating the formation of ore freezes due to its overconsolidation and freezing during interruptions in ore unloading is achieved by using a crushing unit in the form of a bowl-mortar with a plate in the base working as an anvil under a rock layer. The parameters of such a cone-shaped device are determined by the impact of pieces up to 1-1.2 m in size, penetrating into the rocks (ore) up to 3-5 m high and creating extreme compressive and tensile stresses in the layer near the surface of the plate, as a result of which the piece is destroyed. The next pieces, hitting a lumpy medium, deepen, displacing the finely and medium-crushed ore mass, and being in a limiting state, if not destroyed, they become anvil for the following pieces and are destroyed. The ore mass displaced from the bowl-stupa by gravity enters the hopper and is in it in a loosened state, then it is fed by the feeder into the crusher, crushed to the required size and then through the intermediate conveyor it enters the main conveyor and is transported by it to the factory or transshipment point. The size of the stupa bowl (diameter) corresponds to the diameter of the ore pass, this eliminates the impact of pieces on its walls (metal). To ensure its performance, it is installed and attached to a reinforced concrete massive base.

When reducing the height of ore passages to 25-30 m, the thickness of the buffer layer above the plate in the bowl-stupa can decrease to a minimum (h _sl = 20-30 cm), which practically does not reduce the quality of ore crushing. The crushing of pieces of ore about a slab was determined during an experiment conducted by the author in the Sami quarry of Apatit OJSC (Monograph “Deep ore passes, section 9 [2]).

According to the research results, even without special crushing of pieces on the slab, the ore self-crushing coefficient, expressed as the ratio of the average piece diameter before passing through the ore pass and after passing, amounted to Apatit Central OJSC for the apatite ore (fortress coefficient f = 8-10) - 2-2.5 , and the output of pieces above +400 mm 2.5-4%.

When using the crushing link, the crushing coefficient can be 4-5, which will reduce the yield of pieces larger than 350-400 mm to 0.5-1%. Crusher (shakovy) can work in the facilitated mode.

The drawings show a section of a section of the conveyor and ore pass with equipment and elements of the method (Fig.2, 3, 4).

Figure 1 - General scheme 1 - ore; 2 - ledge; 3 - guide (body); 4 - slicing layers; 5 - crushing link (bowl-stupa); 6 - plate; 7 - base (reinforced concrete, precast); 8 - hopper; 9 - crusher (jaw type ShchDP); 10 - plate feeder; 11 - intermediate conveyor; 12 - main conveyor; 13, 14, 15 - development;

Figure 2 - diagram of the cutout of the mouth of the ore 16 - well; 17 - dispersed charges in the wells; 18 - selected blocks.

Figure 3 - layout of wells and sections of the sequence of blasting wells.

Figure 4 - diagram of the element of the crushing link with crushed ore entering the hopper.

Concrete example

On the basis of technical and economic analysis, for the Nyorkpakhskoye and Oleniy Ruchey apatite ore deposits represented by hollow and inclined ore bodies, it was found that instead of using motor vehicles with a transport shoulder of 3-16 km on the surface, it is more expedient to use opencast mine conveyors with conveyor transport ore to a transshipment point. The ore transportation distance for the first deposit will be 1.5-2 km, for the second - 3-3.5 km.

The height of the benches h _y = 15 m. Drilling of wells by the SBSh-250 MN machine, transportation of ore to ore passes by Belaz-7519 dump trucks.

Ore slopes have a height of 200-350 m, depending on the mountainous terrain, their diameter is 3 m.

Sump testing to design depth is as follows.

After sinking of ore passes in the area of their bottom, a crushing link (bowl-stupa) is installed with a base in the form of a powerful plate 6 and a height of 3 m with an angle of inclination of the walls to the base of 45-60 ° and is mounted on a reinforced concrete base, a hopper with a feeder 10 (plate, used in factories), a chamber 13 is being constructed for a crusher (jaw type ShchDP) with a productivity of 1.5-2000 t / h and the necessary equipment (intermediate conveyor), a route is being created for the main conveyor 12. The capacity of the hopper is 8 3-5 thousand tons, calculated taking into account unevenness loading ore into the ore pass 1.

Before loading the ore into the ore pass in the stupa bowl 5, a protective layer with a thickness of 1.5-2 m is created and at the beginning crushed ore is loaded with separation of pieces 1-1.2 m, and then ordinary ore is sent.

As mining operations decrease in a quarry, cutting is performed (redemption of ore passes 1). For this, a ledge 2 with a height of 15 m is divided in height into layers 4 with a thickness of 4-5 m, depending on the block composition of the rocks of the 18 array around ore pass 1. Drilling of wells 16 during excavation of the first layer is carried out according to a ring pattern with thickening to the walls of the ore pass and a variable depth. The diameter of the wells is 200-250 mm. The distance between the walls of the ore pass and the first row is 0.5-1 m, then the depth between the rows increases to 2-3 m. The depth of the wells of the first row is 3.5-4 m, the last 4.5-5 m. This eliminates the possibility of chipping blocks near the walls of the ore pass and their getting into the ore launching trunk. The magnitude of the charge 17 in the wells 16 is regulated depending on the size of the crushed block and the identified individuality limited by cracks. This eliminates the underworking of blocks. Blasting the rows of wells in sections with the opposite direction of the rocks, exploding from opposite sides of the ore pass, which contributes to the completion of the material. After completion of work on removing layers of rocks, a new mouth of the ore pass is formed with undisturbed walls and a stable array, and oversized pieces do not fall into the ore pass, and the work of the ore pass, and therefore the quarry, is stable and rhythmic in nature.

Sources of information

1. Rzhevsky V.V., Arsentyev A.A., Anistratov Yu.I. and other quarry ore passes. M .: Subsoil. - 1969. - 208 p.

2. Gushchin V.V., Epimakhov Yu.A. Kozyrev A.A. et al. Deep ore passes. Apatity., Tr. Kola Scientific Center. - 1997 .-- 195 p.

Claims (1)

A method for open-cast mining of steeply dipping and inclined deposits involves mining the quarry to the design depth using opencast ore mines with accumulating bunkers, cutting ore mines as mining operations deepen in the quarry, crushing oversized materials and rock blocks from the dump from the bunker walls using explosives (explosives), loading ore to railway transport, cutting and redeeming the upper part of ore passes at each horizon when mining operations approach them is carried out by dividing into layers and accesses from behind in rows in the wells, ensuring crushing of the rock to a standard size and preservation of the walls of the mine, and further reducing the size of the pieces and increasing the efficiency of ore discharge by eliminating ore hangs is achieved by using a crushing link in the form of a bowl-mortar with a plate in the base that works as an anvil under the rock layer , from which the ore mass flows by gravity into the hopper and from it is fed by a feeder to the crusher and then through an intermediate conveyor to the main conveyor.

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