RU2396430C1 - Method for reclamation of sludge pond compartment filled with grainy wastes of industrial enterprises - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to hydraulic engineering and may be used in reclamation of sludge ponds. Method includes formation of reclamation body over compartment from wastes in tiers, and its outer surface is faced as convex with specified height, and this surface is coated with soil layer. Each tier is arranged by inwash of tier body to form settling pond and beach zone, realised under protection of barrier element erected along perimetre of tier with earth-moving equipment and providing for giving the reclamation body specified shape of external surface within the height of tier body. Barrier element in cross section is erected serially in parts. At first upstream fill is erected from soil material, then beach zone wastes are used to erect downstream fill, afterwards head wall is arranged from soil material suitable for further coating of external surface of reclamation body. Head wall is arranged over upstream fill and partially over downstream fill. It consists of temporary (cut) part and permanent, which forms a layer of soil with variable thickness over upstream fill and partially over downstream fill. Downstream fill is erected by means of excavator, which is equipped with dragline, moves in upstream fill, processes wastes of beach zone and puts them down into downstream fill. External surface is shaped as specified, afterwards it is coated with a layer of soil material taken from temporary part of head wall in barrier element of previous tier. Area of cross section in temporary part of head wall Wg in erected barrier element satisfies the following condition: w_B<bxe_S> where b - width of outer surface of downstream fill in barrier element subject to coating intended to erect the tier following in height by inwash; e_S - thickness of soil layer. If a drain trench is arranged along compartment perimetre on upstream side from its barrier dam, its depth provides for lowering surface of soil water in body and foundation of barrier element in lower tiers of recultivation body below foot of layer of their seasonal freezing.

EFFECT: reduced costs and environmental expenses, increased reliability and wider field of application.

5 cl, 3 dwg

Description

The invention relates to hydraulic engineering and can be used in the reclamation (conservation) of hydraulic dumps, for example tailings, sludge collectors and ash and slag dumps.

A known method of reclamation (conservation), according to which the section of the hydraulic dump is washed with waste to the design level, then the reclamation is stopped and reclamation is carried out [1 and 2].

However, the final state of the surface of the hydraulic dump does not provide a convenient relief. Therefore, when planning, the central part of the section is built up with waste taken from the beach area and imported quarry soil, thus creating a planning body over the section as an element of the technical stage of reclamation (hereinafter: reclamation body). At the same time, the enclosing dams, which received the calculated hydraulic loads during the process of washing the waste into the section, are cut up to 20 percent in height. In addition, the presence of unconsolidated water-saturated waste in the central part of the section does not allow to begin restoration work for a long time after the completion of the washing up of the waste, which delays the transfer of the section area for further use. In addition, the final fill factor of the hydraulic dump with this method of reclamation is 0.75-0.85, and planning work and delaying the reclamation cause anomalous entry into the atmosphere of small fractions of waste in the form of dusting, especially at ash and slag dumps. All this leads to high costs and significant environmental costs.

A known method of reclamation of a section of a hydraulic dump filled with granular waste from industrial enterprises, including forming over a section created by enclosing dams from waste from the reclamation body (scum body) by pinning the pulp into the central part from the pulp duct located above the section, and coating the outer surface of the reclamation body with a layer the soil. In this case, the excess water entering the section is sent through the water supply system to the waste water transport water supply system, and the height position of the outer surface of the reclamation body ensures that after sedimentation in the section, the convex shape necessary for the water to drain from its surface is preserved [3].

The disadvantages of this method, reducing its effectiveness, are as follows:

- directly along the enclosing structures around the entire perimeter of the section, a narrow pond channel is formed, the water of which causes a high hydraulic effect on the enclosing structures, which reduces the reliability, especially the environmental, of the waste-filled section;

- from the channel pond it is necessary to periodically remove the sludge that has settled in it, which is associated with additional costs;

- the entire reclamation body is saturated with water, which in the winter season under pressure acts on the layer of seasonal freezing of waste with the formation of heaving tufts and keys that destroy the outer side surface of the reclamation body, which reduces the reliability of the reclamation body being created;

- throughout the entire period of such a formation of a body of reclamation practically without a pond, it is necessary to carry out dust suppression on the entire surface of the section, which is associated with high costs and significant environmental costs;

- the slope of the outer surface of the body of reclamation during the point of release of the pulp is formed in a natural and almost uncontrolled way, and its value depends on the physicomechanical characteristics of the waste and may be insufficient, while the slope changes (decreases) in the direction from the place of release of the pulp to the enclosing dams, which It does not provide the formation of an optimally prescribed body shape of reclamation.

A known method for the construction of a tailing pond, in which along the longitudinal axis of the tailings accumulator from one enclosing dam to the opposite anti-aircraft alluvium from the tails, a dividing dam is formed, the crest of which exceeds the crest of the enclosing dams. Then, the plots transfer to a two-sided dispersed pulp outlet, as a result of which, by the time the drive is full, its surface acquires a convex profile, which increases the capacity of the tailings pond and makes it possible to start all work on the technical stage of reclamation in series by plots [4].

The disadvantages of this method, reducing its effectiveness, are as follows:

- a high degree of readiness of enclosing structures for the beginning of dispersed alluvium;

- fencing dams along the entire perimeter of the tailings for a long time are under high hydraulic impact of surface and groundwater;

- insufficient ability to carry out reclamation until the tailing dump is completely filled;

- the presence of unconsolidated water-saturated tailings near the enclosing dams does not allow to begin restoration work for a long time after the completion of the alluvium at the site;

- uncontrollability of the formation of the optimal convexity of the surface of the drive.

There is a method in which land allotment for a tailing dump is divided into sections with a service life of one to two years and they are put into operation sequentially one after another. Moreover, the embankment is being deboned in the third section, the second is being exploited, and in the first section, reclamation is carried out 2-4 years after the start of operation of the tailings [5].

In fact, a method for the construction and reclamation of a multi-section tailing dump, the filling of each section, i.e. site, carried out in 1-2 years. When implementing this method, difficulties arise, firstly, with the formation of a settling pond of the dimensions necessary for taking water from it, and secondly, with the liquidation of this pond during site planning. All this reduces the efficiency and narrows the scope of the use of the method as the construction of the tailings, and its reclamation.

There is also a method of reclamation (conservation) of a section of a hydraulic dump filled with granular waste from industrial enterprises, adopted as a prototype, which includes performing a drainage trench along the perimeter of the section from the top of its enclosing dam, buried in the section waste and lowering the level of ground water in front of the enclosing dam, forming section from the waste body reclamation (conservation) with giving it a given height convex shape of the outer surface, and covering this surface with a layer of soil. At least the lower part of the reclamation body is formed by tiers, each of which is performed by washing the tier body with the formation of a settling pond and the beach area, carried out under the protection of the enclosing element, erected along the perimeter of the tier from earth-moving equipment dehydrated before development of the beach zone waste, mainly by means of a bulldozer , and providing within the limits of the height of the tier body, giving the body reclamation the specified shape of the outer surface [6].

The disadvantages of this method, reducing its effectiveness and narrowing the scope of its use, are as follows:

- the complexity of dehydration before the development of fine-grained and / or dusty waste, for example, ash and slag of thermal power plants, which increases costs and narrows the scope of the method;

- the material of the tip, temporarily performing structural and technological functions in the enclosing element, is not used productively enough, which increases costs;

- dusting intensity during the development and movement of dehydrated waste with a bulldozer, which leads to environmental costs;

- the reclamation body is saturated with water, which in the winter season can under pressure affect the layer of seasonal freezing of waste with the formation of heaving tufts and keys that destroy the outer side surface of the performed part of the reclamation body, which reduces the reliability of the method.

The problem to which the invention is directed is to increase the efficiency of the method, and the technical result achieved in the implementation of the method is to reduce costs and environmental costs, to increase reliability and to expand the scope of use.

To achieve the specified technical result in the proposed method, which includes forming a reclamation body over the section from the waste, giving it a height-shaped outer surface, and covering this surface with a soil layer, at least the lower part of the reclamation body is formed in tiers, each of which are carried out by washing the tier body with the formation of a settling pond and the beach area, carried out under the protection of the enclosing element, erected along the perimeter of the tier with earthmoving equipment and providing according to the invention, the enclosing element in cross section is erected sequentially in parts, first the elevated prism is erected from the soil material, then a lower prism is erected from the waste from the beach area, and then from the soil material suitable for subsequent coating of the outer surface of the body of reclamation, i.e. layer of soil, erect a head, which is located above the upper and partially above the lower prism and which consists of a temporary (cut) part and a constant, forming a layer of soil above the upper and partially above the lower prism, and the lower prism is erected by means of an excavator that moves along the upper prism , produces waste from the beach area and puts it in a downstream prism, the outer surface of which, after giving it a given shape, is covered with a layer of soil material of the temporary part of the head of the enclosing electric ment previous tier, and the cross-sectional area of the tip portion of the temporary w erected _in the boundary element satisfies the following condition:

w _in ≤b × e _p ,

where b is the width of the outer surface of the lower prism of the enclosing element to be coated, which is intended to be erected for washing up the next tier in height;

e _p - the thickness of the soil layer (coating).

Additionally:

- the excavator is equipped with a dragline;

- along the perimeter of the section on the upper side of its enclosing dam perform a drainage ditch;

- in the case of the perimeter of the section on the upper side of its enclosing dam of the drainage trench, buried in the waste section and lowering the surface of the groundwater in front of the dam, the depth of the drainage trench provides a lowering of the surface of the groundwater in the enclosing element and in the body of the tier in the lower (first a) tiers of the body of reclamation below the sole of the layer of their seasonal freezing;

- the section is supplied with water conduits providing drainage of water from the drainage ditch and the drainage trench outside the section.

The main distinguishing features of the proposed method, ensuring the achievement of the specified technical result, is a group of features in successive parts of the construction of the head of the enclosing element using a dragline excavator, specification of the soil material and the size of the head, temporarily performing structural and technological functions in the enclosing element and performing perimeter section of the drainage ditch and a drainage trench with a specified value of its depth.

The invention is illustrated by drawings, in which the section is depicted at the time of completion of the 8th tier, while the degree of reduction of horizontal dimensions exceeds the degree of reduction of vertical dimensions in figure 1 by 10 times, in figure 2 - 5 times, in figure 3 - without reduction:

- figure 1 shows the reclaimed section of the hydraulic dump, cross section;

- figure 2 - node 1 in figure 1;

- figure 3 is a transverse section through the enclosing element.

Section 1 (hereinafter: section) was created on a flat terrain with fencing dams 2 and filled to the design level with waste that is fine-grained and / or dusty, for example, ash and slag of thermal power plants. Wastes of beach zone 3 are characterized by a filtration coefficient k _f <1 m / day and a slope of the beach surface 4 i _pl <0.005, a fraction of one, and beach 4 itself has a weak bearing capacity. Prudkovy zone 5 is composed of dusty clay fractions. The excess water that entered the section when it was filled, through the waste water wells, drain pipes and the discharge channel not shown in the drawings, was directed to the waste water recycling water supply system, carried out via the main slurry line. Reclamation is carried out by forming a reclamation body 6 over the section from the waste, giving it the convex shape of the outer surface 7 given by height, and covering this surface with a soil layer 8. The lower and middle part of the reclamation body 6 is formed in tiers 9, each of which is made by washing from waste body tier 9 with the formation of a settling pond 10 and beach area 3. This alluvium is carried out under the protection of the enclosing element 11, erected around the perimeter of the tier 9 intended for the implementation of earthmoving equipment flowing within the height h _i of the tier 9 body, giving the reclamation body 6 a predetermined shape of the outer surface 7.

Already during the first tier 9, along the perimeter of the section, on the top side of the dam 2, if the section is not drained, a drainage trench 12 is made. The depth of the drainage trench 12 into the waste of the section provides a lowering of the surface water table (depression curve) 13 in front of the enclosing dam 2 by a given value, and in the body and base of the enclosing element 11 - below the sole 14 of the seasonal freezing layer. At the same time perform a catchment ditch 15, which is located above the drainage trench 12 or near it. Section 1 is provided with water conduits (not shown) that drain the water from the catchment ditch 15 and the drainage trench 12 outside of section 1.

The enclosing element 11 (Fig. 3) in cross section consists of an upper prism 16, a lower prism 17 and a head 18. The head 18, temporarily performing structural and technological functions, consists of a temporary (cut-off) part 19 and a constant part 20, which forms a layer soil 8 of variable thickness above the high prism 16.

The enclosing element 11 is erected sequentially in parts. First, a top prism 16 is erected from the soil material, then a bottom prism 17 is erected from the beach waste. After all this, a head 18 is erected from the soil material suitable for subsequent coating of the outer surface of the reclamation body 6. This head is placed above the horse 16 and partially above grassroots 17 prism. The lower prism 17 is erected by means of an excavator 21, which is equipped with a dragline, moves along the upper prism 16, produces waste products in the open pit 22 of the beach zone 3 and puts them into the lower prism 17. Using a bulldozer (bulldozer not shown), the outer surface of the lower prism 17 is given the desired shape and its cover layer 8 soil (soil) temporary material (of cut) portion 19 of tip 18 enclosing member 11 of the previous tier 9. The cross sectional tip portion of the temporary w erected _in the boundary lementa satisfies the condition:

w _in ≤b × e _p ,

where b is the width of the outer surface of the lower prism of the enclosing element to be coated, which is intended to be erected for washing up the next tier in height;

e _p - the thickness of the soil layer (coating).

In the given dependence, subject to the “less” condition, when soil layer 8 is performed on the site, additional delivery of soil material will be required, and if the condition is “equal”, the soil balance will be optimal. Figure 3, the width of the coating b = 24 m, provided that the coating is performed ahead of the construction of the head 18 of the subsequent tier 9.

The angle of inclination of the surface of the body of reclamation with respect to the horizon α usually does not exceed 3 degrees [7]. When the height of the tier h _i = 1.5 and the accepted slope of the body of the reclamation i _p = 0.05, the distance between the axes of the heads of the 18 enclosing elements 11 (the width of the reclamation strip) l = h _i / i _p = 1.5 / 0.05 = 30 m

When washing the bodies of tiers 9, the water is taken from the sludge pond 10 by first building up spillway wells (not shown), then by constructing new spillway wells (not shown) or by performing floating machine or siphon water intakes 23. Formation of the upper part 24 of the reclamation body 6 is carried out in according to the project.

The proposed method has the following advantages.

1. Mounting prism 16 and head 18 both during construction and during operation practically do not create dusting.

2. The requirements of stability are imposed on the mount prism 16. As an extreme case, the bottom prism 17 can completely take on the anti-filtration functions when washing up the body of the tier 9. Moreover, the volume of the high prism 16 is not large, its height usually does not exceed 1.5 m, and the pavement 25 specially for the excavator 21 may not be required or be lightweight, and without the use of geosynthetics.

3. The axis of the excavator is equidistant both from the open pit 22 and from the center of the lower prism 17. This allows the use of a dragline excavator with a moderate boom length, which will reduce the cost of excavating waste.

4. Excavator 21, equipped with a dragline, develops waste that is due to capillary rise of water in a wet state, and, if necessary, below groundwater level. After laying such wet and water-saturated wastes in the bottom prism 17, they immediately give them the desired shape and cover with a soil layer immediately in short sections with bulldozer 8. Under these conditions, these works are carried out practically without the formation of dry waste surfaces and they do not create significant dusting and do not require significant dust suppression costs watering machines.

5. The soil material of the head 18 is used productively, first it is temporarily used in the enclosing element 11, then - constantly in the conservation body 6, as its soil layer 8.

The indicated advantages of the method to the specified extent cannot be provided when the road 25 is located under the excavator 21 both at the surface with a weak bearing capacity of the beach 4, and on the crest of the head 18, as well as at another intermediate level.

Used sources

1. Recommendations for the design of ash and slag dumps of thermal power plants: P 26-85 / VNIIG, L., 1986. P.67-68.

2. Recommendations for the reclamation of waste ash and slag dumps of thermal power plants. " RD 34.202-95.M .: SPO ORGRES, 1997.

3. USSR copyright certificate No. 1052614. The method of wet storage of tailings tailing. / Saratov I.E., Remizov B.I., Bondarenko A.I. et al., IPC E02B 7/06, 1981.

4. RF patent No. 2162151. The method of construction of the tailings. / Makeev A.Yu., Zoteev V.G., Kamkin I.R. and other IPC Е02В 7/06, Е21C 41/26. Filed 2000.04.26. Publ. 2001.01.20.

5. RF patent №2335631. A method for the joint construction and reclamation of a tailing dump. / Senkus V.V., Perfilov A.A., Senkus V.V. and other IPC Е21С 41/32, ЕОВВ 7/06, Filed 2006.10.31. Publ. 05.05.10.

6. RF application No. 2007141429. A method of preserving a section of a hydraulic dump of granular waste from industrial enterprises. / Vaikum V.A., Rudnov V.M., Yagin V.P., IPC Е02В 7/00. Filed November 7, 2007. Publ. 05/20/2009.

7. Recommendations for the reclamation of waste ash and slag dumps of thermal power plants. RD 34.202.-95 / RAO "UES of Russia". - M.: SPO ORGRES, 1997.

Designations

1 - section

2 - enclosing dam (sections)

3 - beach area

4 - beach (surface)

5 - pond zone

6 - reclamation body

7 - outer surface (reclamation bodies)

8 - soil layer (coating)

9 - tier (reclamation bodies)

10 - settling pond

11 - enclosing element

12 - drainage trench

13 - depression curve

14 - sole of the layer of seasonal freezing

15 - drainage ditch

16 - mount prism (enclosing element)

17 - grassroots prism (enclosing element)

18 - head (fencing element)

19 - temporary (cut) part of the head

20 - the constant part of the head

21 - excavator (dragline)

22 - quarry

23 - floating water intake

24 - upper body reclamation

25 - pavement

h _i - the height of the tier body.

i _pl - beach slope

i _p - the slope of the surface of the body of reclamation

e _p - the thickness of the soil layer (coating)

l - the distance between the axes of the heads of the enclosing elements

b is the width of the outer surface of the lower prism of the enclosing element

α is the angle of inclination of the surface of the body of reclamation in relation to the horizon.

Claims (5)

1. The method of reclamation of a section of a hydraulic dump, filled with granular waste from industrial enterprises, comprising forming a reclamation body above the section from waste, giving it a convex shape of a given height that is set to the height of the outer surface and coating this surface with a soil layer, at least the lower part of the reclamation body being formed tiers, each of which is performed by washing the tier body with the formation of a settling pond and a beach area, carried out under the protection of the enclosing element, erected along the perimeter of the tier and with earthmoving equipment and providing, within the tier body height, giving the body reclamation a predetermined shape of the outer surface, characterized in that the enclosing element in the cross section is erected sequentially in parts, with the top prism being erected first from the ground material, then the bottom prism being erected from the beach waste, then from soil material suitable for subsequent coating of the outer surface of the body of reclamation, i.e. layer of soil, erect a head, which is located above the upper and partially above the lower prism and which consists of a temporary (cut) part and a constant, forming a layer of soil above the upper and partially above the lower prism, and the lower prism is erected by means of an excavator that moves along the upper prism , produces waste from the beach area and puts it in a downstream prism, the outer surface of which, after giving it a given shape, is covered with a layer of soil material of the temporary part of the head of the enclosing electric ment previous tier, and the cross-sectional area of the tip portion of the temporary w erected _in the boundary element satisfies the following condition:
w _in ≤b × e _p ,
where b is the width of the outer surface of the lower prism of the enclosing element to be coated, which is intended to be erected for washing up the next tier in height;
e _p - the thickness of the soil layer. 2. The method according to claim 1, characterized in that the excavator is equipped with a dragline. 3. The method according to claim 1, characterized in that along the perimeter of the section on the upper side from its enclosing dam perform a drainage ditch. 4. The method according to claim 1, characterized in that in the case of performing along the perimeter of the section on the top side of its enclosing dam a drainage trench buried in the waste section and lowering the surface of the groundwater in front of the boundary dam, the depth of the drainage trench provides a lowering surface of the groundwater in the body and the base of the enclosing element in the lower (first) tiers of the body of reclamation below the bottom of the layer of their seasonal freezing. 5. The method according to claim 3 or 4, characterized in that the section is equipped with water conduits to drain water from the drainage ditch and the drainage trench outside the section.

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