Uranium mine stope waste radiation integrated treatment method

Abstract

The invention belongs to the technical field of mine stope treatment, and particularly relates to a uranium mine stope waste radiation integrated treatment method. The exposed residual ore body at the bottom of the exposed mining stope is covered with concrete, the gamma radiation dosage is reduced, and stope stabilization and radiation shielding are achieved. According to the method, the waste backfilling sequence is planned, the waste with the high radon exhalation rate is backfilled to the bottom according to the radon exhalation rate sequence, the waste with the lower radon exhalation rate is backfilled from top to bottom, the waste serves as a covering material, the covering amount of clean clay is reduced, soil source ground damage is reduced, the gamma radiation dose rate is reduced, and meanwhile radon exhalation is reduced. According to the method, revealed ruins and other site treatment are considered as a whole, waste backfilling of other sites is subjected to unified treatment and comprehensive planning, it is guaranteed that all links are linked, and it is guaranteed that the landscape pattern of final ecological restoration is coordinated with the surrounding environment.

Description

Technical Field

[0001] The invention belongs to the technical field of mine site management, and in particular relates to a method for integrated radiation management of uranium mine site waste. Background Art

[0002] With the development of industry, the mining industry has provided a large amount of mineral resources for industrial production through mining. However, the geographical distribution of open-pit mines in my country is mostly close to densely populated areas, where there is little arable land. Open-pit mining causes great damage to the surface of the earth. The volume of open-pit pits is huge and the locations are numerous and scattered. This not only aggravates the tension between people and land, but also there are residual ores left at the bottom of the open-pit pits, with a high radon emanation rate. A large amount of earthwork is required for covering and management, which breaks the village landscape pattern.

[0003] At present, people generally landfill waste residues of different situations and then cover them with ordinary gravel soil. However, this rough treatment method has no radiation reduction effect on the radiation mining site after open-pit mining of radioactive frames such as uranium mines. The gamma radiation is high, and rainwater can easily penetrate, causing the harmful substances in them to be oxidized and leached, and then flow out with the seepage water. The seepage water exceeds the standard and is difficult to collect and treat, resulting in the inability to reclaim the land and affecting the effective use of the land. Summary of the invention

[0004] The purpose of the present invention is to provide a method for integrated radiation treatment of waste from uranium mines. The method provided by the present invention is safe and effective, and the landscape pattern of ecological restoration is coordinated with the surrounding environment.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for integrated radiation treatment of uranium mine waste, comprising the following steps:

[0007] (1) The exposed residual ore at the bottom of the uranium mine is covered with concrete and first covering clay in sequence, and the exposed residual ore at the bottom of the uranium mine is covered with second covering clay;

[0008] (2) For a uranium mine site with a slope greater than 1:2, the waste is filled in the slope in a predetermined order and then covered with clay until the slope is no more than 1:2; the predetermined order is: the radon exhalation rate of the waste decreases from bottom to top, and in particular, when the void ratio of the waste with the smallest radon exhalation rate is greater than that of the waste with the second smallest radon exhalation rate, the order of the waste with the smallest radon exhalation rate and the waste with the second smallest radon exhalation rate is exchanged;

[0009] (3) For uranium mines with a slope of no more than 1:2, the radon exhalation rate should be less than 0.74 Bq / (m 2 .s) The waste is filled in the slope and then covered with clay;

[0010] There is no time sequence requirement for steps (1) to (3).

[0011] Preferably, the thickness of the covering concrete is 0.20-0.30 m.

[0012] Preferably, the concrete used for the covering concrete is C20 concrete.

[0013] Preferably, the thickness of the first covering clay is 0.40-0.60 m.

[0014] Preferably, the thickness of the second covering clay is not less than 0.8 m.

[0015] Preferably, the thickness of the third covering clay is not less than 0.8 m.

[0016] Preferably, the thickness of the fourth covering clay is not less than 0.8 m.

[0017] Preferably, the waste includes one or more of waste residue, tailings, dirt and construction waste.

[0018] Preferably, the waste slag includes one or both of residual ore and waste rock.

[0019] Preferably, the tailings are heap leaching tailings.

[0020] The present invention provides a method for integrated radiation control of waste in uranium mines. The present invention uses concrete to cover the exposed residual ore bodies at the bottom of the open-pit mining site, thereby reducing the gamma radiation dose and achieving site stabilization and radiation shielding. The present invention plans the order of waste backfilling, and backfills the waste with high radon exhalation rate at the bottom in the order of radon exhalation rate, and backfills the waste with lower radon exhalation rate as it goes up. The waste is used as a covering material to reduce the amount of clean clay covered, reduce soil source damage, reduce the gamma radiation dose rate, and reduce radon exhalation. After monitoring, the radon exhalation rate was reduced by more than 80%, and the radon exhalation rate was less than 0.25Bq / m 2 .s. The present invention takes into account the management of open-pit mining ruins and other sites, unifies the management of waste backfill from other sites, makes comprehensive plans, ensures that each link is linked together, and ensures that the final ecological restoration landscape pattern is coordinated with the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of radiation treatment of exposed residual ore bodies in an open-pit uranium mine.

[0023] Figure 2 This is a schematic diagram of integrated management of an open-pit uranium mine site with a slope greater than 1:2 in Example 1;

[0024] Figure 3 This is a schematic diagram of integrated management of an open-pit uranium mine site with a slope not greater than 1:2 in Example 1;

[0025] Figure 4 This is a schematic diagram of the overall structure of the integrated management of an open-pit uranium mine site in Example 1. DETAILED DESCRIPTION

[0026] The present invention provides a method for integrated radiation treatment of uranium mine waste, comprising the following steps:

[0027] (1) Cover the exposed residual ore at the bottom of the uranium mine with concrete and clay in turn, and cover the exposed residual ore at the bottom of the uranium mine with clay;

[0028] (2) For a uranium mine site with a slope greater than 1:2, the waste is filled in the slope according to a predetermined order and then covered with clay until the slope is no more than 1:2; the predetermined order is: the radon exhalation rate of the waste decreases from bottom to top, and in particular, when the void ratio of the waste with the smallest radon exhalation rate is larger than that of the waste with the second smallest radon exhalation rate, the order of the waste with the smallest radon exhalation rate and the waste with the second smallest radon exhalation rate is exchanged;

[0029] (3) For uranium mines with a slope of no more than 1:2, the radon exhalation rate should be less than 0.74 Bq / (m 2 .s) waste is filled on the slope and then covered with clay;

[0030] There is no time sequence requirement for steps (1) to (3).

[0031] The present invention sequentially covers the exposed residual ore at the bottom of the uranium mine with concrete and covering clay (referred to as the first covering clay, specifically as follows Figure 1 As shown in FIG. 1 , the bottom of the uranium mine site where there is no exposed residual ore is covered with clay (referred to as the second covering clay). In the present invention, the concrete used for the covering concrete is preferably C20 concrete.

[0032] In the present invention, the thickness of the covering concrete is preferably 0.20-0.30 m, specifically 0.20 m, 0.22 m, 0.24 m, 0.26 m, 0.28 m or 0.30 m.

[0033] In the present invention, the method of covering with concrete preferably further includes measuring the volume of the uranium mine site. The present invention measures the volume of the uranium mine site to obtain the waste requirement for backfilling the uranium mine site.

[0034] In the present invention, the thickness of the first covering clay is preferably 0.40-0.60 m, and specifically may be 0.40 m, 0.43 m, 0.45 m, 0.48 m, 0.50 m, 0.52 m, 0.55 m, 0.57 m or 0.60 m.

[0035] In the present invention, the thickness of the second covering clay is preferably not less than 0.8 m, and specifically may be 0.8 m, 0.9 m, 1.0 m, 1.1 m, 1.2 m, 1.5 m, 1.8 m, 2.1 m, 2.5 m, 3 m, 5 m, 8 m or 10 m.

[0036] The present invention fills wastes in a predetermined order on a slope with a slope greater than 1:2 in a uranium mine, and then covers the wastes with clay (recorded as the third covering clay) until the slope is no more than 1:2; the predetermined order is: the radon exhalation rate of the wastes decreases from bottom to top, and in particular, when the void ratio of the waste with the smallest radon exhalation rate is greater than that of the waste with the second smallest radon exhalation rate, the order of the waste with the smallest radon exhalation rate and the waste with the second smallest radon exhalation rate is exchanged.

[0037] In the present invention, the source of the waste is preferably a mine, specifically including one or more of a small-area mine (less than 30% of the area of ​​a uranium mine), a dispersed mine, a mine near a residential area, a mine near a planting area, and a mine that is used without restriction after decontamination; the waste preferably includes one or more of waste residue, tailings, soil, and construction waste; the waste preferably includes one or two of residual ore and waste rock; the tailings are preferably heap leaching tailings. The present invention uses different materials for backfilling and radiation shielding covering of uranium mines according to the slope and location.

[0038] Among the wastes collected by the present invention, residual ore, waste rock and tailings generally have high radon release rates and high radioactive content, while contaminated soil and construction waste generally have low radon release rates. Among them, the radon release rate of residual ore is 0.70-2.00 Bq / (m 2 .s), the radon release rate of tailings is 0.95~0.50Bq / (m 2 .s), the radon release rate of waste rock is 0.70~0.30Bq / (m 2 .s), the radon exhalation rate of polluted soil is 0.30~0.16Bq / (m 2 .s), the radon release rate of construction waste is less than 0.07Bq / (m 2 .s).

[0039] In the present invention, the packing thickness of the waste is preferably determined by the amount of the collected waste.

[0040] In the present invention, the thickness of the third covering clay is preferably not less than 0.8 m, and specifically can be 0.8 m, 0.9 m, 1.0 m, 1.1 m, 1.2 m, 1.5 m, 1.8 m, 2.1 m, 2.5 m, 3 m, 5 m, 8 m or 10 m.

[0041] The present invention reduces the radon exhalation rate to less than 0.74 Bq / (m 2 .s) of waste is filled on the slope and then covered with clay (referred to as the fourth covering clay).

[0042] In the present invention, the thickness of the fourth covering clay is preferably not less than 0.8 m, and specifically can be 0.8 m, 0.9 m, 1.0 m, 1.1 m, 1.2 m, 1.5 m, 1.8 m, 2.1 m, 2.5 m, 3 m, 5 m, 8 m or 10 m.

[0043] In order to further illustrate the present invention, the scheme of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be understood as limiting the protection scope of the present invention.

[0044] Example 1

[0045] The method for integrated radiation treatment of uranium mine waste in this embodiment includes the following steps:

[0046] (1) Determine the amount of waste to be collected based on the capacity of the open-pit uranium mine site; transport all the solid waste from a certain mine to the open-pit uranium mine site for filling and burial, so that the mine reaches the level of unlimited use.

[0047] (2) There are exposed residual ore at the bottom of the open-pit uranium mine, and the surface is covered with 0.30m thick C20 concrete and then covered with 0.50m thick clay. The area at the bottom where there is no exposed residual ore is leveled and compacted, and the surface is covered with 1m thick clay.

[0048] (3) The side slope of the open-pit uranium mine in this embodiment is flattened and compacted on the spot, and is divided into A to D steps from the bottom to the top. The overall structure is as follows Figure 4 As shown:

[0049] AC side slope: the original site is leveled and compacted, and the solid waste slag (thickness 0.5-0.8m), heap leaching tailings (thickness 1.5-2m), waste rock (thickness 0.5-0.8m), construction waste (thickness 1-1.2m, the void ratio is greater than the waste soil, the filling order of the two is swapped) and waste soil (thickness 0.3-0.5m) transported from the entire mine are backfilled in sequence, and the slope is filled and leveled at the same time, and covered with 1m of clay to form a slope with a slope not greater than 1:2;

[0050] Point C: The original site is leveled and compacted, and a platform is arranged at point C to form a C platform. The width of the C platform is 4m and covered with 1m of clay to maintain the long-term stability of the slope;

[0051] Point D: The original site is leveled and compacted, and a platform is arranged at point D to form platform D. The width of platform D is 4m, backfilled with 2m of construction waste and covered with 1m of clay to maintain the long-term stability of the slope;

[0052] CD side slope: the original site is leveled and compacted, and the steps of backfilling, leveling and covering are the same as those of AC side slope. Figure 2 As shown;

[0053] DB side slope: level and compact the original site, backfill 0.5-0.8m of solid waste slag transported from the entire mine, cover with 1m of clay, and build drainage ditches. Figure 3 As shown;

[0054] Point B: The surface is covered with C20 concrete with a thickness of 0.30m, and then covered with clay with a thickness of 1m.

[0055] This embodiment solves the environmental pollution problem of open-pit uranium mines, and the radon release rate is 0.82-5.34 Bq / (m 2 .s) is reduced to 0.195~0.253Bq / (m 2 .s), ecologically restored open-pit uranium mines will be coordinated with natural landscapes and rural villages, while small and contaminated sites will be relocated and centralized for cleanup to ensure maximum and unrestricted use of land.

[0056] It can be seen from the above embodiments that the method provided by the present invention achieves site stabilization and radiation shielding, reduces the coverage of clean clay, reduces soil source damage, reduces the gamma radiation dose rate, and at the same time reduces radon release, and the landscape pattern of ecological restoration is coordinated with the surrounding environment.

[0057] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for integrated radiation treatment of uranium mine waste, characterized in that: The following steps are involved: (1) The exposed residual ore at the bottom of the uranium mine is covered with concrete and first covering clay in sequence, and the exposed residual ore at the bottom of the uranium mine is covered with second covering clay; (2) For a uranium mine site with a slope greater than 1:2, the waste is filled in the slope in a predetermined order and then covered with clay until the slope is no more than 1:2; the predetermined order is: the radon exhalation rate of the waste decreases from bottom to top, and in particular, when the void ratio of the waste with the smallest radon exhalation rate is greater than that of the waste with the second smallest radon exhalation rate, the order of the waste with the smallest radon exhalation rate and the waste with the second smallest radon exhalation rate is exchanged; (3) For uranium mines with a slope of no more than 1:2, the radon exhalation rate should be less than 0.74 Bq / (m 2 .s) The waste is filled in the slope and then covered with clay; There is no time sequence requirement for steps (1) to (3).

2. The method according to claim 1, characterized in that The thickness of the covering concrete is 0.20-0.30 m.

3. The method according to claim 1 or 2, characterized in that: The concrete used for the covering concrete is C20 concrete.

4. The method according to claim 1, characterized in that: The thickness of the first covering clay is 0.40-0.60 m.

5. The method according to claim 1 or 2, characterized in that: The thickness of the second covering clay is not less than 0.8 m.

6. The method according to claim 1 or 2, characterized in that: The thickness of the third covering clay is not less than 0.8 m.

7. The method according to claim 1 or 4, characterized in that: The thickness of the fourth covering clay is not less than 0.8 m.

8. The method according to claim 1, characterized in that The waste includes one or more of waste residue, tailings, dirt and construction waste.

9. The method according to claim 8, characterized in that The waste slag includes one or both of residual ore and waste rock.

10. The method according to claim 8, characterized in that The tailings are heap leaching tailings.

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