RU2490459C1 - Method to mine thick steep deposits of unstable ores - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method to mine thick steep deposits of unstable ores includes separation of an ore body into floors, and floors - into horizontal or flat layers, mined in a descending order, extraction of ore within layers by stopes, filling of the mined space with hardening materials, tunnelling of stopes of the second and further layers under the filling mass. When mining the second and subsequent layers, they tunnel primary and secondary stopes, first primary stopes are tunnelled, the distance between which is accepted as equal to width of the secondary stope, after filling of the primary stopes with hardening material and gaining of normative strength by the hardening material they tunnel secondary stopes between filling massifs established in primary stopes, at the same time when tunnelling primary stopes their side surfaces are given a shape of planes inclined to the side of adjacent secondary stopes, and the angle between the side surface of the primary stope and the horizontal surface is determined on the basis of the expression.

EFFECT: increased safety of mining works and reduced costs for tunnelling of stopes.

2 dwg

Description

The invention relates to the mining industry and can be used in underground mining of powerful steeply dipping deposits of unstable ores.

A known method of developing deposits of unstable ores (Patent RU No. 2309253, publ. 10/27/2007), including the separation of the ore body into horizontal or slightly inclined layers, worked out in an ascending order, excavation of layers with horizontal or slightly inclined treatment openings and tab filling with hardening materials.

The disadvantages of this method are the increased danger of sewage treatment associated with the collapse of the roof and sides of the openings, as well as the significant cost of securing the openings and laying the worked out space. This is explained by the periodic, as the layers are mined, deformation of the undermined ore mass associated with incomplete filling of the worked out space with filling material, compaction of the filling mass in the process of hardening and conducting cleaning operations in the layers. Due to the increase in the degree of disturbance of the undermining ore mass, the transition to the mining of each new upstream layer is accompanied by an increase in the risk of mining and production costs.

A known method of developing steeply declining deposits of unstable ores (Patent RU No. 2209972, publ. 08/10/2003). This method includes dividing the ore body into floors, and floors into horizontal or slightly inclined layers, worked out in a descending order. In the layers are starting preparatory workings. The extraction of ore within the layers is carried out by horizontal or slightly inclined treatment openings, passable from the starting preparatory workings. Snapshots after their full-length are laid with hardening materials. As starting workings, drifts or orts are used.

The disadvantages of this method in the development of powerful steeply dipping deposits of unstable ores are the increased danger of treatment and significant costs for fixing treatment plants.

A known method of developing powerful steeply dipping deposits of unstable ores (Patent RU No. 2405108, publ. 11/27/2010). This method, adopted as a prototype method, includes dividing the ore body into floors, and floors into horizontal or slightly inclined layers, worked out in a descending order. Excavation of ore within the layers by fillings, laying of worked out space with hardening materials. Driving through the passages of the second and subsequent layers under the backfill array created during mining of the above layers.

The disadvantages of this method when developing powerful steeply dipping deposits of unstable ores are:

- Increased risk of mining due to the high intensity of spontaneous collapse of rocks and ore from the sides of the openings of the second and subsequent layers located under the filling array.

- Low penetration rate of the entry, associated with the need to clean the rock mass that collapsed from the side of the entry and the “frill” of the side surfaces of the entry before filling in; installation along the entire length of the tabs lining with overlapping sides of the tabs with a special tightening.

The technical result of the proposed method is to increase the safety of mining and reduce the cost of sinking.

The technical result is achieved by the fact that in the method of developing powerful steeply dipping deposits of unstable ores, including dividing the ore body into floors, and floors into horizontal or slightly inclined layers mined in a descending order, excavation of ore within the layer with fillings, laying of worked out space with hardening materials, penetration of the fill of the second and subsequent layers under the stowage array, during the development of the second and subsequent layers, primary and secondary approaches pass, first primary visits pass and, the distance between which is taken equal to the width of the secondary pass, after laying the primary passages with hardening material and a set of hardening material of standard strength between the filling arrays created in the primary passages, secondary passages pass, while during the passage of the primary passages their lateral surfaces are shaped like planes that are inclined in the direction of adjacent secondary entries, and the angle between the lateral surface of the primary entry and the horizontal plane is determined from the expression

φ≥arctgh / 1,

where: φ is the angle of inclination of the lateral surfaces of the primary approaches to the horizontal plane, deg;

h is the height of the entry, m;

1 - depth of distribution into the ore mass in the side of the primary entry of the area of destruction of the ore mass by rock pressure when the lateral surface of the primary entry is located at an angle of 90 ° to the horizontal plane, m

The essence of the proposed method for the development of powerful steeply dipping deposits of unstable ores is illustrated by the schemes presented in figure 1 and figure 2.

The diagram in figure 1 illustrates the sequence of penetration of primary and secondary entries of the second layer under the filling array created during mining of the first layer.

Figure 1: 1 - ore mass;

2 - filling array created as a result of filling up the worked out space (completed passages) with hardening materials;

3, 5, 7 - primary entries (3 and 5 are laid with hardening materials, 7 - passed, but not laid with hardening materials);

4, 6 - secondary entries (4 - passed, but not laid by hardening materials, 6 - in the sinking stage).

8 - ore mass;

a - the width of the primary entries, m;

b is the width of the secondary leads, m;

m is the power of the first layer, m;

h is the thickness of the second layer (the height of the second layer), m

φ is the angle of inclination of the lateral surfaces of the primary approaches to the horizontal plane, deg.

Figure 2 presents a diagram explaining the location on the side of the primary entry of the area of destruction of the ore mass by rock pressure when the lateral surface of the primary entry is located at an angle of 90 ° to the horizontal plane.

Figure 2: a - the width of the primary entry, m;

OR - the side surfaces of the primary entry, located at an angle of 90 ° to the horizontal plane;

OPF - areas of destruction of the ore mass by rock pressure in the sides of the primary entry;

1 - depth of distribution into the ore mass in the side of the primary entry of the area of destruction of the ore mass by rock pressure when the lateral surface of the primary entry is located at an angle of 90 ° to the horizontal plane, m

The method is as follows.

The ore body is divided into floors, and floors into horizontal or slightly inclined layers, which are worked out in a descending order. The extraction of ore within the layer is carried out by sinking. The worked out space (completed passages) is laid with hardening materials.

When working out the second and subsequent layers, primary and secondary approaches are distinguished. Initially, primary approaches of width a pass, the distance between which is taken equal to the width of the secondary approach b. When driving primary approaches, their lateral surfaces are shaped into planes inclined towards adjacent (adjacent) secondary approaches, and the angle between the side surface of the primary approach and the horizontal plane is determined from the expression φ≥arctgh / 1.

The sinking of primary sits with inclined lateral surfaces is technically easy to implement both when sinking sips with selective action combines (for example, P-110, AM-50), and with a blasting method of sinking them.

After laying the primary entries and gaining standard strength with the hardening material between the filling arrays created in the primary entries, secondary entries pass. So the primary entry 3 and 5 (figure 1) passed and laid hardening material. The lateral surfaces DC and NM of these passages are inclined towards the secondary pass 4. After the hardening material in the passages 3 and 5 reaches the standard strength, pass the secondary run 4 and lay it with hardening material.

Giving during sinking of the primary openings 3, 5 and 7 (Fig. 1) to their lateral surfaces form planes inclined towards the secondary openings, and the location of the lateral surfaces of the primary openings at an angle φ≥arctgh / 1 to the horizontal plane allows to reduce the intensity of spontaneous ore collapse from sides of the primary sunset. This is because the ore from the OPF regions (Fig. 2) by the rock pressure of the ore mass in the sides of the primary sinking is extracted during sinking.

When the distance between the primary runs 3, 5 and 7, (Fig. 1), equal to the width of the secondary runs b, and the secondary walks 4 and 6 after laying the primary walks with hardening material and a set of hardening material of standard strength between the filling arrays created in the primary walks , eliminates the possibility of spontaneous collapse of the sides of the secondary entries. This is explained by the fact that, at the indicated distance between the primary entries and the accepted sequence of operations in the sides of the secondary entries, there is a stable filling array of hardening materials.

The depth 1 of spreading into the ore mass in the side of the primary entry of the area of destruction of the ore mass by rock pressure when the side surface of the primary entry is located at an angle of 90 ° to the horizontal plane (Fig. 2) is determined in each case using well-known methods of mine, laboratory or analytical studies.

The parameters a, b, m and h are determined during the design of the technological scheme for mining the ore body, taking into account the influence of geological and mining factors.

Using the proposed method can improve the safety of mining and reduce the cost of sinking. Improving the safety of work is associated with: the exception of spontaneous collapse of the ore mass from the sides of the openings; improving the quality of bookmarks of the worked-out space. The reduction in costs is associated with: a decrease in the volume of work associated with stripping cuts from the ore mass and "frill" of the side surfaces of the cuts before performing filling operations; reducing the cost of fastening and tightening the sides of the openings; an increase in penetration rate.

The inventive method is intended for use in underground mining of powerful steeply falling ore deposits, characterized by low strength characteristics of the ores. In the Russian Federation, this method with significant social (security) and economic effect can be used in the development of rich iron ore deposits of the Belgorod group: Yakovlevsky, Gostischevsky, etc.

An example of a specific application in the conditions of the Yakovlevsky mine.

A steeply dipping rich iron ore deposit is being mined at the Yakovlevsky mine. The main types of ores of this deposit are loose iron-mica-martite and martite-iron-mica ores with low uniaxial compressive strengths, from 0.3 to 15 MPa.

The development system is layered, the order of mining layers is descending. The thickness of the layer is 4.5 m, the width of the primary (a, figure 1) and secondary (b, figure 1) of the entry - 5 m

When conducting mining operations of the second and subsequent layers under the stowing massif under the conditions of the Yakovlevsky mine, as a result of increased rock pressure, the ore mass in the sides of the openings is destroyed and the ore mass spontaneously collapses into the openings. At the same time, up to 5-6 tons of ore and more collapses in the areas of openings about 5 m long. The depth 1 (figure 2) of the distribution into the ore mass in the side of the primary entry of the area of destruction of the ore mass by rock pressure when the lateral surface of the primary entry is located at an angle of 90 ° to the horizontal plane is 0.5-1.0 m

When implementing the proposed method, the frequency of cases of spontaneous dangerous collapse of the ore mass from the sides of the openings decreases several times, the total reduction in the cost of conducting and maintaining treatment openings leaves at least 15-20% compared with the known methods, the speed of penetration of openings increases by at least 10-15%.

Claims (1)

A method for developing powerful steeply dipping deposits of unstable ores, including dividing the ore body into floors, and floors into horizontal or slightly inclined layers mined in descending order, excavation of ore within the layer by fillings, laying of worked out space with hardening materials, drilling of fillings of the second and subsequent layers under the filling array characterized in that during the development of the second and subsequent layers, primary and secondary approaches pass, first primary visits pass, the distance between they are taken equal to the width of the secondary run-in, after laying the primary run-by hardening material and a set of standard strength by hardening material between the filling arrays created in the primary run-in, secondary run-ins pass, while during the passage of the primary run-in their lateral surfaces are shaped to planes inclined towards adjacent secondary sunset, and the angle between the lateral surface of the primary sunset and the horizontal plane is determined from the expression
φ≥arctgh / l,
where φ is the angle of inclination of the side surfaces of the primary approaches to the horizontal plane,
h is the height of the entry,
l is the depth of distribution into the ore mass in the side of the primary entry of the area of destruction of the ore mass by rock pressure when the lateral surface of the primary entry is located at an angle of 90 ° to the horizontal plane.

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