RU2256075C1 - Method for open extraction of mineral resource deposits - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: method includes opening deposit at distance 150 meters from river and forming of natural filtering wall between river and trench, pumping of water from trench into river, extraction of mineral resource, revegetation of dumps, filling of trench with water, accomplishment of formed water body. Mineral resource is extracted from two serially opened trenches - auxiliary, revegetated as water body, and main, positioned at opposite side of river, and soil from opening of which is used for revegetation of auxiliary trench, while in main trench along whole board on the side of river right beyond mining operations inner dump is formed with width not less than 250 meters and with height at same level with earth surface, water from trenches is fed into river, and then into water body through intermediate collectors, while after forming of water body currents of soil waters between trenches and river are made balanced, balance level is estimated on basis of water levels in auxiliary trench and river.

EFFECT: higher efficiency.

1 dwg, 1 ex

Description

The invention relates to the mining industry and can be used in open pit mining of mineral deposits (PI) located in the coastal zone of rivers, as well as in flooded areas.

The known method / Method of open development of mineral deposits. E 21 C 41/26, No. 1662166, bull. No. 8, 03.20.95 /, where mining of PI in conditions of severe flooding is carried out using drainage penetrations and trenches. After opening the PI around it, diverging trenches are carried out by diverging branches, and the PI is mined from the center to the periphery. The disadvantage of using this method is the violation of groundwater currents, which leads to shallowing and even loss of rivers adjacent to the place of development of PI.

The known method / Method of opening and development of shallow-lying stratified mineral deposits. E 21 C 41/26, No. 1675555, bull. No. 33, 09/07/91 /, in which two trenches, the main and the auxiliary, are opened from different sides of the field. From the trenches, the mine workings are being conducted for the deposit and mining is carried out. In this way, the costs of reclamation of the worked-out field are reduced, but they do not solve the problem of groundwater flow and river conservation.

The known method / Method of water-technical reclamation of used upland pits. E 21 C 41/32, No. 2120552, publ. 1998.10.20 /; which consists in layer-by-layer filling of the quarry zone with the formation of a hydroaccumulating cavity in the lower layer. To raise the groundwater level, an additional well is created, connected to the storage cavity. The quarry is filled in such a way as to ensure the flow of water from it. The method cannot be used in low zones and floodplains.

Known methods of reclamation of landscapes disturbed by open cast mining / Motorina L.V., Zabelina N.M. Reclamation of land disturbed by the mining industry. Overview. M., 1968 /. On the site of former quarries in the USSR, Germany, USA, Canada, ponds were created for recreation of people and household needs. A distinctive feature of mining is their durability. Duration of quarries is tens of years. Relatively strict environmental laws also appeared several decades ago. In this regard, the technology for developing deposits of building materials, coal, referred to in this review, did not include measures for the rehabilitation of quarries in water bodies. At the end of the mining, PI the quarries filled with water were cleaned, the banks were rehabilitated under forest stands and meadows. The disadvantage of such a mining of PI is that nature is not saved, but restored.

The closest prototype of the proposed method from among the known technical solutions is the method of extraction of building materials and reclamation of a quarry under a pond in the area of Zhukovsky, Moscow Region / I. Lazareva. Restoration of disturbed areas for urban development. Publishing house of construction literature. M., 1972 (p. 38-39) /. The method consists in the fact that the opening of the sand-gravel mixture is carried out at a distance of 150 m from the river. This creates a natural filter jumper between the river and the trench. In the process of developing such a quarry, located near the river, water is pumped, as a rule, into the river. After extracting the PI, dumps are reclaimed by afforestation and filling the trench with water during floods and ground inflow through the filtering jumper. Improvement of the formed reservoir is carried out.

The disadvantage of this method is the possibility of its effective application only in the development of building materials. For example, in the extraction of shallow coal, there will be a lack of soil for reclamation of dumps, dumping of the sides and bottom of the created reservoir. The application of the method in the development of several quarries, including on different sides of the river, will lead to a change in the water regime of the river, its shallowing, up to the disappearance, clogging of water pumped from the trenches in a mixture with coal dust.

The proposed method is aimed at eliminating the noted drawbacks, and the following result can be obtained from its use: with more complete extraction of PI, the return of land for economic use will accelerate.

The specified result is achieved due to the fact that PIs are opened and mined from two trenches in succession: the auxiliary, which is being restored under the reservoir, and the main one, located on the opposite side of the river. At the same time, in the main trench along the entire non-working side from the river side, immediately after mining, dumping of the internal dump is carried out at least 250 m wide and at the level of the earth's surface. It is proved by calculation and experimental methods that such a thickness of the bridge is an obstacle to the flow of groundwater. The soil from the opening of the main trench is used for the restoration of the auxiliary trench. Water from the trenches is pumped into the river and the reservoir (after the end of the extraction of PI) through intermediate sumps made in the form of tanks. In this case, after the creation of the reservoir, the flow of groundwater between the trenches and the river is achieved, as judged by the water levels in the river and the reservoir.

It should be noted that the method is also applicable to the special case when trenches are located on one side of the river. At the same time, natural jumpers are also provided, according to the method dumps and pumping systems are created.

An example of the method can be shown on the development of the Balakhta coal mine in the Krasnoyarsk Territory (“Conclusion ...”, Appendix 1).

In the drawing, the positions indicate: 1 - auxiliary trench, 2 - natural filtering bridge, 3 - river, 4 - internal dump of the main trench, 5 - main trench, 6 - contour of the main trench development, 7 - water conduit from the trench to the sump, 8 - sump auxiliary trench, 9 - water conduit from the sump to the river, 10 - the gate-distributor, 11 - the sump of the main trench.

Exploration indicates a coal deposit in the area of river 3 (the width of the river called Cheese is up to 10 m, the average depth is 1 m, valuable fish species are found). Coal lies on both sides of the river at a depth of 4-10 m from the surface. The formation height is up to 18-36 m, reserves are estimated at 200 million tons.

At a distance of 150 m from the river, an auxiliary trench 1 is being developed, i.e. a recess, measuring 900 × 300 m over the surface and 30 m deep. Through a natural filtering jumper 2, water from the river enters trench 1. From trench 1, water is pumped through conduit 7 to a settling tank adjacent to the trench 8. There may be several sedimentation tanks, these are ponds with a waterproofed inner surface. After sedimentation of suspended particles and, if necessary, additional purification, the water is returned to the river 3 through the water conduit 3. Coal is extracted from the drained trench 1. Based on the pace of development of the auxiliary trench 1, the start time of the development of the main trench 5 is established, the overburden of which is used as material for filling the spent space of the auxiliary trench 1 for the future reservoir.

The development of the main trench 5 from the river side is carried out in such a way that immediately behind the coal excavation an internal dump 4 is created with a width of 250-300 m and a height at the level of the earth's surface. This event significantly reduces the outflow of water from the river into the trench through the corresponding jumper. The main trench 5 is drained by pumping water into the river through the adjoining sump 11 through water conduits equipped with a gate-distributor 10. The gate-distributor allows water to be directed from the sump 11 either to river 3 or to the auxiliary trench 1. After coal mining from the auxiliary trench is completed 1 and its preparation as a reservoir bed, the pumping of water into the river is stopped. After 10-15 months, the reservoir will be filled with water from the river through jumper 2, groundwater through the entire surface of the bed, atmospheric floods and water pumped out of the main trench through the sump 11 and the shutter-distributor 10. With the filling of the trench, it is necessary to observe the balance of water flows and monitor the level water in the river and created pond. The level should correspond to design values, which depend on the rate of water filtration through jumpers, atmospheric precipitation, degree of evaporation, and household water intakes. The specified condition is met by dumping the inner blade 4 and the pumping system through the device 10, 11.

As the side of the main trench moves away from the river towards the development contour 6, the water inflow through the bridge from the river decreases, and the main trench can become auxiliary for the next cycle of work on its restoration into the reservoir. And the created reservoir is a single hydraulic system with a river. The surface of the blade 4 is reclaimed under forest stands and fields.

Thus, using the proposed method provides almost complete extraction of coal, preservation of the river and its biological resources, as well as the constant return of the worked land to economic use in the form of clean reservoirs and a landscaped area.

Claims (1)

A method of open development of mineral deposits (PI), including opening a deposit at a distance of up to 150 m from the river and creating a natural filter bridge between the river and the trench, pumping water from the trench into the river, extracting PI, reclamation of dumps, filling the trench with water, landscaping the reservoir , characterized in that PIs are opened and mined sequentially from two trenches - auxiliary, recultivated under a pond, and the main one, located on the opposite side of the river, and soil from overburden to They use it to reclaim the auxiliary trench, while in the main trench along the entire side of the river, immediately after mining, dumping of the internal dump is not less than 250 m wide and at the level of the earth's surface, the water from the trenches is pumped into the river, and then into the body of water through intermediate sedimentation tanks, and after creating the reservoir, they ensure that the groundwater currents between the trenches and the river are balanced, as judged by the water levels in the auxiliary trench and the river.