RU2524716C1 - Strip mining of minerals including working of ore bodies in contact between ore and capping in sub-benches - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: proposed method comprises drilling the vertical wells, charging the latter, placing the charges, short-delay blasting of said wells and selective excavation. Blasting of blocks is performed in bulk. Note here that all three dimensions of blasted block, i.e. width, length and height, are set irrespective of the position of contacts and the number of ore bodies. After block blasting, portion of shotpile is dumped over slope roof with working of the first pass over rock on the side of ore body hanging side. Depending on attitude of ore body in blasted block, selective working of productive bench is performed in two sub-benches with mining in layers.

EFFECT: decreased losses of ore and ore dilution.

1 dwg

Description

The invention relates to the mining industry and can be used in the development of steeply falling ore deposits with a complex mineralization structure.

There is a method of developing ore bodies in the contact zones of ore and overburden with sub-steps (No. 2398111, published: 04/08/2009), including dividing the productive layer in the contact zones into sub-steps with a height depending on the angle of inclination of the ore body, its power, and development from drilling wells from the lying side of the deposit at a distance from the horizontal contact corresponding to the minimum area of the lost ore triangle.

The disadvantage of this method is that it is associated with the implementation of the initially large volume of stripping operations from the side of the hanging side of the pool with a large ore body capacity and does not reduce ore loss when working out contact from the side of the lying side of the pool.

A known method of processing explosive blocks (No. 2012806, published 05/15/1994), including the development of blasted rocks by allowing them to selectively be developed by an excavator by changing the contact angle to a ledge coordinated with the slope, when the ore losses and its clogging are reached are the same as during mining with a consistent drop in contact.

The disadvantage of this method is the need to create additional blast holes, which leads to an increase in the cost of drilling and blasting.

There is a method of open pit mining of inclined inclined strata of a mineral (No. 2062879, published 06/27/1996), which includes opening the upper seam horizontally with a trench from the side of the hanging side by an excavator, working out a rock triangle between the side of the trench and the roof of the upper seam, mining the upper seam, inter-layer and the underlying formation with a time and space lag to a depth equal to the depth of the cut trench with the shipment of the rock mass in vehicles.

The disadvantage of this method is the complexity of the development technology due to the involvement of additional mining equipment. The invention relates to the development of adjoining inclined formations and is least suitable for the development of steeply falling ore deposits.

A known method of processing explosive blocks (No. 2102598, published 01.20.1998), including the extraction of minerals with the help of taps with the development of the last calls in the forward and reverse directions sequentially from top to bottom and its shipment to vehicles in order to improve the quality of the extracted minerals, reduce losses and reduce the cost of crushing by thin-layer milling.

The disadvantage of this method is the need to engage in the process of additional extraction equipment (cable scraper), which leads to an increase in the cost of excavation work.

There is a method of developing near-contact zones (Khokhryakov B.C. Open-pit mining of mineral deposits. M .: Nedra, 1982. - 280 p.), During which wells are drilled to the height of the ledge and the layer is worked out equally from the side of the lying side and the hanging one.

The disadvantage of this method is that this does not take into account the influence of either the angle of incidence of the ore body or its power, which leads to increased losses of ore and its dilution.

A known method of processing explosive blocks (No. 2012806, published 05/15/1994), adopted as a prototype, including the development of blasted rocks by providing the possibility of their selective development by an excavator by changing the contact angle to a ledge coordinated with the slope upon reaching the ore loss and its clogging are the same as when developing with a consistent drop in contact.

The disadvantage of this method is the need to create additional blast holes, which leads to an increase in the cost of drilling and blasting.

The technical result is to reduce losses of ore and its dilution.

The technical result is achieved by the fact that the preparation of the rocks for excavation is carried out mainly by the gross method; in accordance with the technology of gross blasting, all three sizes of the blasting block (width, length and height) or some of them are set regardless of the position of the contacts and the number of ore bodies; initially, a part of the collapse is shipped along the roof of the ledge with the first penetration through the rock from the side of the hanging side of the ore body; depending on the occurrence conditions, the development of a 10-meter production ledge in two sub-steps of 5 m and with the division of the sub-height of 5 m in height should be provided; to increase the level of selective excavation during the development of low-grade ore bodies, a 5-meter approach can be worked out by excavation layers of 2.5 m each.

The method is illustrated in figure 1.

Figure 1. The procedure for mining the bottom with sub-steps. The sequence numbers show the order of development.

A cutting trench is passed through the ore zone using blasting. The width of the cutting trench H is determined by the parameters of the technological equipment used, as well as by the quantity and endurance of the contour of the ore bodies. Sequence numbers 1-7 (figure 1) shows the sequence of development of the prepared block, the development of the block is carried out from the side of the hanging side of the ore body with sequential mining of sub-steps. Projects of mass explosions for stripping, mining and mining and preparatory work are developed in accordance with the "Typical project for the production of mass explosions."

Blasting ore blocks taking into account the minimum disturbance of natural occurrence should be predominantly gross in a clamped environment. During gross blasting, all three sizes of the blasting block (width, length and height) or some of them are set regardless of the contact position of heterogeneous rocks on the basis of general technological considerations. Separate blasting is necessary when it is possible to carry out simultaneous or selective blasting of ore bodies and rocks.

Multi-row short-delayed gross blasting of a block can be carried out by a selected (open) front of work, in a clamped environment and with a retaining wall of unassembled blasted rock.

Multi-row blasting in a clamped medium provides a more complete preservation of the parameters of ore bodies occurring after an explosion due to the lower coefficient of loosening of rocks after the explosion (Cr = 1.05 ÷ 1.2).

At the stage of ore excavation from co-exploded complex blocks, there is a separate mining of ores for processing at the factory and using heap leaching technology, non-industrial (wretched) ores and waste rock. At the same time, ore mining is carried out under the following basic conditions:

- blasting of rock and ore is predominantly gross;

- the position of the contact "ore-rock" and ore grades is determined by the geological service with the exposure of pegs on the collapse of the blasted rock mass;

- excavation of the rock mass in a complex face is always carried out in the direction from the hanging side of the ore body to the lying one, with the least losses and dilution of the ores. The development of ore bodies (RT) from the lying side of the deposit to the hanging is prohibited;

- depending on the conditions of occurrence, it is necessary to develop a mining ledge in two sub-steps of 5 m and with a sub-sub-division of 5 m high. To increase the level of selective excavation in the development of low-grade ore bodies, a 5-meter sub-approach can be worked out by 2.5 m excavation layers;

- in accordance with the technology of gross blasting, all three sizes of the blasted block (width, length and height) or some of them are set regardless of the position of the contacts and the number of RTs based on the required volume of the finished blasted rock mass;

- initially part of the camber is shipped along the roof of the ledge, with the first penetration through the rock from the side of the hanging side of the RT.

The extraction of ores from co-exploded complex blocks is accompanied by separate extraction of ores for processing at the factory and using heap leaching technology, non-industrial (wretched) ores and waste rock.

In case of separate excavation of ore-rock, sorting (separate excavation and loading) is carried out only by the width of the face. With separate excavation, the conditional quality of the extracted mineral is achieved: by the correct choice of the method, sorting methods and the procedure for mining the face, by carefully preparing the face for an explosion, by installing an excavator as close as possible to the face.

In the method of sorting with separate scooping of ore and rock, it is advisable to divide the face into sub-steps of 4-5 m high, to work out each sub-step in layers of 2-2.5 m in height. To ensure standard losses and dilution in the given geological conditions, the layer height is calculated sorting.

Separate digging is achieved by adjusting the thickness of the chips and the degree of filling of the bucket and usually starts from the top of the face, provided that the height of the face does not exceed the height of digging of the excavator (Нз <Нч).

Separate excavation is characterized by a separate excavation by the value of the maximum radius of excavator digging along the width of the excavator entry followed by loading of ores and rocks. The extraction of the rock mass can be carried out by an ECG excavator or hydraulic, with which the selective excavation can be improved.

Claims (1)

The method of open development of mineral deposits, including the mining of ore bodies in the zones of contact of ore and overburden with pockets, including drilling vertical wells, loading wells, placing charges, short-blasting wells, selective development by an excavator, characterized in that the blocks are blasted using a gross method, all three sizes of the blasting block — the width, length and height — are set regardless of the position of the contacts and the number of ore bodies; after the blasting of the block, part of the shaft on the roof with the sinking of the first shoulder stope breed by the hanging wall of the ore body, depending on the conditions of occurrence of ore bodies in exploded block selective mining ledge development is carried out in two podustupa followed by working off of the recessed layers.

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