In-situ leaching mine hydrometallurgy plant wastewater evaporation system and construction method thereof

Abstract

The invention provides an in-situ leaching mine hydrometallurgy plant wastewater evaporation system and a construction method thereof, and belongs to the technical field of wastewater treatment.The evaporation system comprises an evaporation pond and a plurality of evaporation frames floating on the liquid level of the evaporation pond; the evaporation frame comprises a rectangular floating frame formed by four side plates, and ventilation holes are formed in the parts, outside the liquid level, of the upper portions of the four side plates; the four corners of the floating frame are provided with angle braces respectively, fixing bolts are arranged in the middles of the angle braces, upper and lower fixing cables are connected between the ends of the fixing bolts of every two adjacent angle braces, and upper and lower suspension cables are connected between the upper and lower fixing cables in parallel. And evaporation strips are arranged on the upper and lower suspension cables in parallel. According to the in-situ leaching mine hydrometallurgy plant wastewater evaporation system and the construction method thereof, evaporation is efficient, environmental protection is achieved, energy consumption is avoided, and the application condition is wide.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a wastewater evaporation system for a geothermal mining hydrometallurgical plant and its construction method. Background Technology

[0002] In my country, some in-situ leaching mines and hydrometallurgical plants generate large amounts of wastewater during operation. Currently, the industry primarily relies on evaporation ponds for wastewater treatment, achieving zero discharge through natural evaporation. The area of ​​the evaporation pond is determined by the ratio of the total annual wastewater discharge to the net evaporation rate of the project area. The calculations include a reduction in natural evaporation to ensure sufficient safety margin in the evaporation capacity. The depth of the evaporation pond is determined through a water balance calculation based on monthly wastewater discharge, evaporation, and rainfall. The evaporation pond structure generally employs a combination of excavation and backfilling. First, according to the calculated design evaporation area, a bottom pond is excavated to a certain depth. Then, the excavated soil is used to build a dike around the pond, forming the evaporation pond at the designed depth. Typically, the evaporation pond is divided into several evaporation units. The bottom and walls are lined with impermeable and protective layers, and polluted wastewater is discharged into the pond through pipes.

[0003] Currently, these mining industries mainly use planar evaporation ponds to treat wastewater from hydrometallurgical plants in in-situ leaching mines. This requires the construction of evaporation ponds of considerable size to form sufficient evaporation capacity. This method occupies a large area, has high engineering costs, a wide range of environmental impacts, and is relatively difficult to remediate after decommissioning.

[0004] To improve the evaporation efficiency of evaporation ponds, the technologies currently used in China to accelerate the evaporation capacity of evaporation ponds mainly include methods such as setting up atomizing devices, heating devices, blowing devices, composite devices, evaporation racks, and / or passive acceleration devices in the evaporation pond.

[0005] Most of these methods require continuous power consumption to achieve a certain degree of accelerated evaporation, and are difficult to implement on a large scale, resulting in significant uncertainty regarding their cost-effectiveness.

[0006] Among them, the method of setting a passive acceleration device in the evaporation tank can improve the evaporation efficiency to a certain extent without generating additional energy consumption by using materials that evaporate quickly or structures that facilitate evaporation. However, the degree of improvement is usually quite limited.

[0007] Therefore, there is an urgent need for an efficient, environmentally friendly, energy-free wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants, and its construction method. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants that is efficient, environmentally friendly, energy-free, and widely applicable, as well as a method for its construction.

[0009] To solve the above-mentioned technical problems, the present invention provides a wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants, comprising: Evaporation tank and multiple evaporation racks floating on the liquid surface of the evaporation tank; The evaporation rack includes a rectangular floating frame composed of four side plates, and ventilation holes are provided on the upper part of the four side plates outside the liquid surface; The floating frame is provided with corner braces at its four corners, and fixed bolts are provided in the middle of the corner braces. Upper fixed cables are connected between the ends of the fixed bolts of two adjacent corner braces at the top, and lower fixed cables are connected between the ends of the fixed bolts of two adjacent corner braces at the bottom. Upper suspension cables are connected in parallel between the upper fixed cables, and lower suspension cables are connected in parallel with the upper suspension cables between the lower fixed cables. An evaporation strip made of porous material is arranged in parallel between the upper and lower suspension cables via an evaporation strip fixing device. The middle part of the evaporation strip is fixed to the upper suspension cable, and the two ends of the evaporation strip are respectively fixed to the two adjacent lower suspension cables below the upper suspension cable. The two ends of the evaporation strip hang down below the liquid surface of the evaporation tank. The direction in which the upper and lower suspended cables are arranged in parallel is perpendicular to the wind direction of the maximum wind frequency, and the parallel evaporation strips face the wind direction of the maximum wind frequency.

[0010] Furthermore, the length of the floating frame is 4.0m to 10.0m, and the width of the floating frame is 4.0m to 6.0m; the thickness of the side plate is 6cm to 25cm, and the height of the side plate is 35cm to 80cm.

[0011] Furthermore, the projection plane of the corner brace is an isosceles right triangle, the length of the right-angled side of the corner brace is 10cm to 80cm, the thickness of the corner brace is 25cm to 70cm, and the corner brace is provided with a through mounting hole in the middle for installing the fixing bolt.

[0012] Furthermore, the fixing bolt includes a nut and a screw. The outer diameter of the lower screw body of the nut matches the inner diameter of the mounting hole. The lower screw body of the nut has a tubular hollow structure and is provided with internal threads. The outer diameter of the lower screw body of the screw matches the inner diameter of the tubular hollow structure of the nut and is provided with external threads. The nut is installed in the mounting hole from one side of the corner brace, and the screw is screwed to the nut from the other side of the corner brace. The nut head and the screw head have circumferential grooves in the middle of their sides. The nut and the screw are fixedly connected to the upper fixing cable and the lower fixing cable through the grooves.

[0013] Furthermore, the distance between the upper fixed cable and the lower fixed cable is 30cm to 75cm, the upper suspended cables are arranged in parallel with equal intervals of 5cm to 20cm, and the lower suspended cables are arranged in parallel with equal intervals of 5cm to 20cm.

[0014] Furthermore, the thickness of the evaporation strip is not less than 2.1 mm, the side-by-side spacing between the evaporation strips is 5 cm to 20 cm, the width of the evaporation strip is 2 cm to 40 cm, the length of the evaporation strip is 110 cm to 130 cm, the length of the evaporation strip on one side above the liquid surface is 5 cm to 15 cm, and the length of the evaporation strip on one side below the liquid surface is 50 cm.

[0015] Furthermore, the evaporation strip fixing device includes a slot and a buckle. The centerline of the slot is provided with a first connecting through hole that matches the outer diameter of the upper suspension cable. The slot is connected to the upper suspension cable through the first connecting through hole. The outer surface of the slot is provided with a fixing groove whose width matches the width of the evaporation strip. The centerline of the buckle is provided with a second connecting through hole that matches the outer diameter of the lower suspension cable. The buckle is connected to the lower suspension cable through the second connecting through hole. The outer side of the buckle is provided with a locking opening whose width matches the width of the evaporation strip.

[0016] Furthermore, the floating frame is a lightweight hollow rectangular frame structure made by rotational molding, and the corner brace and the floating frame are integrally molded. The floating frame and the corner brace are made of high-density polyethylene or linear low-density polyethylene. The fixing bolt is a lightweight hollow structure made by rotational molding, and the fixing bolt is made of high-density polyethylene material; The upper and lower fixing cables are made of ultra-high molecular weight polyethylene fiber or polyester fiber. The upper and lower suspension cables are made of ultra-high molecular weight polyethylene fiber or polyester fiber. The slots and buckles of the evaporation strip fixing device are made of high-density polyethylene. The evaporation strip is made of polyester, polypropylene, or polyester nonwoven geotextile with long or short filaments.

[0017] This invention also provides a method for constructing a wastewater evaporation system for a geothermal mining plant, comprising the following steps: Collect data on the average annual evaporation and rainfall of the hydrometallurgical plant area, the duration and flow rate of wastewater discharge from the hydrometallurgical plant, and the area of ​​the proposed evaporation pond; The number of evaporation strips arranged inside the evaporation rack is calculated based on the preliminary basic technical parameters of the evaporation rack, and the height of the floating frame, the width of the side plate of the floating frame, and the size of the reserved holes in the floating frame are determined by buoyancy calculation. Based on the empirical formula for the additional evaporation capacity provided by a single evaporator:

[0018] The additional evaporation capacity that a single evaporator can provide is calculated; Where EM represents the additional evaporation capacity that a single evaporator can provide, m 3 / a; n is the number of evaporation strips in a single evaporator, in strips; A is the area of ​​a single evaporation strip, in m². 2 / strip; E is the local evaporation rate, m³ / a; l is the parallel spacing of the evaporation strips, m, with a value ranging from 0.05m to 0.2m; b is the width of the evaporation strip, m, with a value ranging from 0.02m to 0.4m; t is the lateral spacing of the top slots of the evaporation strips, m, with a value ranging from 0.05m to 0.2m; S is the horizontal projected area of ​​the evaporator frame, m². 2 ; Based on the proposed evaporation pond area, wastewater discharge, annual net evaporation, and the additional evaporation capacity provided by a single evaporator, the number of evaporators required for the evaporation pond is determined, forming the final evaporation system.

[0019] Furthermore, the basic technical parameters of the evaporator include the size of the floating frame, the length and width of the evaporation strips, the spacing between the parallel evaporation strips, and the lateral spacing of the top slots of the evaporation strips.

[0020] This invention provides an evaporation system for wastewater from a geothermal leaching mine. A number of evaporation racks are placed in the evaporation tank of the geothermal leaching mine to form an auxiliary evaporation matrix. The evaporation racks float on the liquid surface of the evaporation tank. Each evaporation rack has a large number of evaporation strips made of porous material, with the bottom of the strips submerged in the liquid and the top exposed. Due to capillary action, the wastewater in the evaporation tank spontaneously rises to the top of the evaporation strips, completely wetting them. Under natural evaporation conditions, the liquid on the evaporation strips quickly evaporates into the air, achieving the evaporation of the wastewater in the evaporation tank. Simultaneously, the continuous evaporation of liquid from the evaporation strips into the air under natural evaporation promotes the continuous capillary action of the evaporation strips, thus forming numerous vertical spontaneous evaporation surfaces in the evaporation tank. This significantly increases the effective evaporation area and evaporation capacity of the evaporation tank, thereby greatly improving the evaporation efficiency of wastewater from the geothermal leaching mine.

[0021] Furthermore, the wastewater evaporation system for leaching mines and hydrometallurgical plants provided by this invention features an evaporation rack where the evaporation strips are fixed in the middle to an upper suspension cable, and both ends are fixed to adjacent lower suspension cables below the upper suspension cable. Most of the ends of the evaporation strips dangle below the liquid surface in the evaporation tank. This arrangement of the evaporation strips within each evaporation rack in an inverted V-shape effectively increases the siphon height of the material used for the evaporation strips. After the evaporation rack is placed in the evaporation tank, the evaporation strips generate a continuous and constant spontaneous siphon, forming numerous vertical evaporation surfaces. This significantly increases the evaporation capacity of the evaporation tank without requiring energy consumption. Moreover, the wastewater evaporation system for leaching mines and hydrometallurgical plants provided by this invention includes ventilation holes in the floating frame portion of the evaporation rack that protrudes above the water surface, facilitating airflow inside and outside the floating frame and thus increasing the evaporation efficiency inside the evaporation rack. Because this invention significantly improves the evaporation efficiency of the evaporation pond, it eliminates the need to rely solely on expanding the horizontal evaporation area to achieve sufficient evaporation capacity. This significantly reduces the footprint of the evaporation pond, effectively saving on construction and decommissioning costs, and minimizing environmental pollution and its impact. Therefore, the wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants provided by this invention not only boasts high evaporation efficiency but also low evaporation costs, resulting in high economic benefits while reducing environmental impact.

[0022] Meanwhile, the wastewater evaporation system for leaching mines and hydrometallurgical plants provided by this invention has an upper and lower suspension cable on the floating frame of the evaporation rack arranged in parallel with the direction of the wind with the maximum wind frequency. The evaporation strips arranged side by side on the upper and lower suspension cables face the wind direction with the maximum wind frequency, which can maximize the conversion of wind power into the evaporation capacity of the evaporation strips. Furthermore, the length of the evaporation strips above the liquid surface is 5cm to 15cm on one side, and the length of the evaporation strips below the liquid surface is 50cm on one side. The exposed height of the evaporation strips is limited, and the exposed part is completely wetted and reliably fixed, giving the evaporation rack strong wind resistance.

[0023] Evaporation racks, as independent evaporation units, can be mass-produced in factories. A certain number of evaporation racks can be placed in the evaporation tank according to project needs to achieve the expected evaporation capacity. This flexible approach allows for easy optimization and adjustment of the evaporation capacity of the evaporation tank. The evaporation racks utilize a floating frame structure to automatically raise and lower the evaporation strips as the liquid level in the evaporation tank changes, avoiding potential problems such as the evaporation strips detaching from the liquid surface or insufficient exposure height under extreme conditions.

[0024] Furthermore, the evaporation racks, which are semi-permanent structures within the evaporation pond, are made of chemically-plasticized materials, making them corrosion-resistant, weather-resistant, and durable, with a service life of several to over ten years. After the evaporation racks freeze in winter, the evaporation pond relies on its reserved volume to temporarily hold the winter wastewater; upon thawing the following year, the evaporation racks will automatically float back to the surface and resume their evaporation capacity. Therefore, the wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants provided by this invention also features a long service life, strong environmental adaptability, and low on-site management difficulty.

[0025] Furthermore, the present invention provides an evaporation system for wastewater from a geothermal mining hydrometallurgical plant and its construction method. When constructing the evaporation system, based on the empirical formula for the additional evaporation capacity provided by a single evaporator, the additional evaporation capacity that a single evaporator can provide in actual production can be calculated. This allows for the preliminary determination of the technical parameters of the evaporator and the number of evaporators to be placed in the evaporation tank. Ultimately, an economical and efficient wastewater evaporation system for a geothermal mining hydrometallurgical plant can be determined, providing a relatively effective mathematical solution for the design and widespread application of wastewater evaporation systems for geothermal mining hydrometallurgical plants. Attached Figure Description

[0026] Figure 1 A top view of the floating frame of a wastewater evaporation system for a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention; Figure 2 This is a side view of the floating frame of a wastewater evaporation system for a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention. Figure 3 A cross-sectional view of the floating frame AA of a wastewater evaporation system for a geothermal mining hydrometallurgical plant provided in an embodiment of the present invention; Figure 4 A cross-sectional view of the floating frame BB of a wastewater evaporation system for a geothermal mining hydrometallurgical plant provided in an embodiment of the present invention; Figure 5 A cross-sectional view of the floating frame of a wastewater evaporation system for a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention; Figure 6 This is a top view of a fixed cable in a wastewater evaporation system for a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention. Figure 7 A cross-sectional view of the fixed cable FF of a wastewater evaporation system in a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention; Figure 8 This is a top view of the nut of a fixing bolt in a wastewater evaporation system of a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention. Figure 9 A cross-sectional view of the nut DD of a fixing bolt for a wastewater evaporation system in a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention; Figure 10This is a top view of a fixing bolt for a wastewater evaporation system in a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention. Figure 11 A cross-sectional view of the screw EE of a fixing bolt for a wastewater evaporation system in a geothermal mining hydrometallurgical plant, provided as an embodiment of the present invention; Figure 12 A top view of the suspension cable of a wastewater evaporation system in a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention; Figure 13 A top view of a slot in a wastewater evaporation system for a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention; Figure 14 A cross-sectional view of the slot HH of a wastewater evaporation system for a geothermal mining hydrometallurgical plant provided in an embodiment of the present invention; Figure 15 A top view of a snap-fit ​​device for an evaporation system of wastewater from a geothermal mining plant, provided in an embodiment of the present invention; Figure 16 This is a top view of the evaporation strips of a wastewater evaporation system in a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention. Figure 17 This is a side view of the evaporation strips of a wastewater evaporation system for a geothermal mining hydrometallurgical plant, provided in an embodiment of the present invention. Figure 18 This is a top view of the overall structure of the evaporation rack in a wastewater evaporation system for a geothermal mining hydrometallurgical plant, as provided in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached drawings: 1-Floating frame, 2-Ventilation hole, 3-Angle brace, 4-Upper fixing cable, 5-Lower fixing cable, 6-Upper suspension cable, 7-Lower suspension cable, 8-Evaporation strip, 9-Mounting hole, 10-Nut, 11-Screw, 12-Slot, 13-Snap, 14-Fixing bolt, 101-Nut thread, 102-Internal thread, 103-Nut head, 104-Nut head groove, 111-Screw thread, 112-External thread, 113-Screw head, 114-Screw head groove, 121-Fixing groove, 122-First connecting through hole, 131-Second connecting through hole, 132-Bayonet. Detailed Implementation

[0028] An embodiment of the present invention provides a wastewater evaporation system for a geothermal mining plant, comprising an evaporation tank and multiple evaporation racks floating on the surface of the liquid in the evaporation tank.

[0029] See Figures 1 to 5The evaporator rack includes a rectangular floating frame 1 composed of four side plates. The floating frame 1 structure should be able to provide sufficient buoyancy for the entire evaporator rack. To reduce the weight of the floating frame 1, it is a lightweight hollow rectangular frame structure manufactured using a rotational molding process. Furthermore, to improve the strength of the floating frame 1, the four side plates are integrally molded. Additionally, to ensure the stability of the floating frame 1 structure, corner braces 3 are provided at each of the four corners of the floating frame 1.

[0030] Among them, the projection plane of the corner brace 3 is an isosceles right triangle, and the corner brace 3 and the floating frame 1 are integrally formed.

[0031] In one specific embodiment of the present invention, the length of the right-angled side of the corner brace 3 is set to 10cm to 80cm, and the thickness of the corner brace 3 is set to 25cm to 70cm.

[0032] Considering factors such as device operating efficiency, stability of the floating frame 1 structure, and ease of management, the length of the floating frame 1 is controlled between 4.0m and 10.0m, the width of the floating frame 1 is controlled between 4.0m and 6.0m, the thickness of the side plate of the floating frame 1 is controlled between 6cm and 25cm, and the height of the side plate is controlled between 35cm and 80cm.

[0033] In order to improve the corrosion resistance and aging resistance of the evaporator, and also to reduce the weight of the evaporator itself, the main floating frame 1 and the corner brace 3 of the evaporator are made of high-density polyethylene or linear low-density polyethylene.

[0034] Furthermore, in order to accelerate the airflow inside and outside the float frame 1 and improve the evaporation efficiency of the wastewater inside the float frame 1, a certain number of ventilation holes 2 are horizontally spaced at intervals on the upper part of the liquid surface of the four side plates of the float frame 1.

[0035] See Figure 6 and Figure 7 To facilitate the fixing of the upper fixing cable 4 and the lower fixing cable 5, a through mounting hole 9 is provided in the middle of the corner brace 3, and a fixing bolt 14 is installed in the mounting hole 9 of the corner brace 3. The upper fixing cable 4 is connected between the ends of the fixing bolts 14 on the upper part of two adjacent corner braces 3, and the lower fixing cable 5 is connected between the ends of the fixing bolts 14 on the lower part of two adjacent corner braces 3.

[0036] The fixing bolt 14 includes a nut 10 and a screw 11.

[0037] See Figure 8 and Figure 9 The outer diameter of the nut body 101 of the nut 10 matches the inner diameter of the mounting hole 9, and the nut body 101 is a tubular hollow structure with an internal thread 102 on the inner wall of the tubular hollow structure of the nut body 101.

[0038] See Figure 10and Figure 11 The outer diameter of the screw body 111 of the screw 11 matches the inner diameter of the nut body 101 of the tubular hollow structure of the nut 10, and the screw body 111 is provided with external thread 112.

[0039] In this design, the nut 10 is installed in the mounting hole 9 from one side of the bracket 3, and the screw 11 is inserted into the mounting hole 9 from the other side of the bracket 3 and screwed into the nut 10, thereby connecting the nut 10 and the screw 11 together to form a fixing bolt 14. Furthermore, in order to ensure that the nut 10 and the screw 11 are tightly connected and prevent them from loosening and falling off, both the nut 10 and the screw 11 are equipped with anti-slip washers (not shown in the figure).

[0040] In one specific embodiment of the present invention, when installing the fixing bolt 14, the nut 10 is first passed through the mounting hole 9 in the middle of the corner brace 3 from top to bottom, and then the screw 11 is screwed into the internal thread 102 of the nut 10 screw body 101 from the bottom of the corner brace 3. The nut 10 and the screw 11 are fastened through their internal thread 102 and external thread 112, thereby achieving effective fixing of the fixing bolt 14.

[0041] In one specific embodiment of the present invention, the upper fixing cable 4 is fixedly connected to the nut 10 of the fixing bolt 14, and the lower fixing cable 5 is fixedly connected to the screw 11 of the fixing bolt 14.

[0042] To facilitate the connection between the nut 10 and the upper fixing cable 4, and to prevent the upper fixing cable 4 from slipping off the nut head 103 of the nut 10, a nut head groove 104 is provided circumferentially in the middle part of the side of the nut head 103 of the nut 10. The upper fixing cable 4 is wound around the nut head groove 104 as a fixed fulcrum. After the upper fixing cable 4 is wound around the nut head groove 104 on the four corner braces 3 of the floating frame 1, the connector of the upper fixing cable 4 is reliably fixed, and the upper fixing cable 4 is fixed to the upper part of the fixing bolt 14.

[0043] Similarly, in order to facilitate the connection between the screw 11 and the lower fixing cable 5, and also to prevent the lower fixing cable 5 from slipping off the screw head 113 of the screw 11, a screw head groove 114 is provided circumferentially in the middle part of the side of the screw head 113 of the screw 11. The lower fixing cable 5 is wound around the screw head groove 114 as a fixed fulcrum. After the lower fixing cable 5 is wound around the screw head groove 114 on the four corner supports 3 of the floating frame 1, the connector of the lower fixing cable 5 is reliably fixed, and the lower fixing cable 5 is fixed to the lower part of the fixing bolt 14.

[0044] Furthermore, the upper fixed cable 4 and the lower fixed cable 5 should be tightened separately during installation to ensure that the upper fixed cable 4 and the lower fixed cable 5 have sufficient resistance to deformation.

[0045] Since the thickness of the corner braces at the four corners of the float frame 1 is less than the height of the side plate of the float frame 1, the upper fixing cable 4 and the lower fixing cable 5 are suspended inside the side plate of the float frame 1 after installation, and the distance between the upper fixing cable 4 and the lower fixing cable 5 is less than the height of the side plate of the float frame 1.

[0046] In one specific embodiment of the present invention, the distance between the upper fixed cable 4 and the lower fixed cable 5 is 30cm to 75cm.

[0047] The fixing bolt 14 is a lightweight hollow structure made using a rotational molding process, and its material is high-density polyethylene. The upper fixing cable 4 and the lower fixing cable 5 are made of ultra-high molecular weight polyethylene fiber or polyester fiber. These materials have stronger corrosion resistance and oxidation resistance, as well as high strength, making components such as the fixing bolt 14, upper fixing cable 4, and lower fixing cable 5 more durable.

[0048] See Figure 12 The upper fixed cables 4 are connected in parallel to the upper suspended cables 6, and the lower fixed cables 5 are connected in parallel to the lower suspended cables 7, which are parallel to the upper suspended cables 6.

[0049] Among them, the upper suspended cables 6 are arranged in parallel with equal intervals of 5cm to 20cm, and the lower suspended cables 7 are arranged in parallel with equal intervals of 5cm to 20cm.

[0050] In this system, an evaporation strip 8 made of porous material is arranged side by side between the upper suspension cable 6 and the lower suspension cable 7 via an evaporation strip fixing device. The middle part of the evaporation strip 8 is fixed to the upper suspension cable 6, and the two ends of the evaporation strip 8 are respectively fixed to the two adjacent lower suspension cables 7 below the upper suspension cable 6, with both ends of the evaporation strip 8 hanging down below the liquid surface of the evaporation tank.

[0051] As a specific embodiment of the present invention, the evaporation strip fixing device includes a slot 12 and a buckle 13. Both the slot 12 and the buckle 13 are perforated structures with connecting holes set along the axis. The slot 12 and the buckle 13 can be pre-connected to the upper suspension cable 6 and the lower suspension cable 7 through the connecting holes, and are reliably fixed to the upper suspension cable 6 and the lower suspension cable 7 according to the design spacing.

[0052] See Figure 13 and Figure 14 The slot 12 has a first connecting through hole 122 at its axial position that matches the outer diameter of the upper suspension cable 6. The slot 12 is connected to the upper suspension cable 6 through the first connecting through hole 122. Furthermore, the outer surface of the slot 12 has a fixing groove 121 with a width matching the width of the evaporation strip 8.

[0053] See Figure 15The buckle 13 has a second connecting through hole 131 at its axis position that matches the outer diameter of the lower suspension cable 7, and the buckle 13 is connected to the lower suspension cable 7 through the second connecting through hole 131. In addition, the buckle 13 has a locking slot 132 on each of its two outer sides, the width of which matches the width of the evaporation strip 8.

[0054] The upper suspension cable 6 and the lower suspension cable 7 are made of ultra-high molecular weight polyethylene fiber or polyester fiber. The slots 12 and buckles 13 of the evaporator strip fixing device are made of high-density polyethylene. These materials have stronger corrosion resistance and oxidation resistance, as well as high strength, making the upper suspension cable 6, lower suspension cable 7, slots 12, and buckles 13 durable.

[0055] See Figure 16 , Figure 17 and Figure 18 The upper part of the evaporation strip 8 is hung on the slot 12 of the upper suspension cable 6, and the two ends of the evaporation strip 8 are respectively passed through the buckles 13 on the two adjacent lower suspension cables 7 at the bottom of the upper suspension cable 6, with the two ends of the evaporation strip 8 hanging down below the liquid surface of the evaporation tank. That is, the ends of the evaporation strip 8 hang down into the wastewater after passing through the buckle 132 on the buckle 13.

[0056] Because the outer surface of the slot 12 has a fixing groove 121 with a width matching that of the evaporation strip 8, when the evaporation strip 8 is hung on the slot 12, it is precisely locked within the fixing groove 121 and will not move left or right on the slot 12. Simultaneously, because the first connecting through hole 122 of the slot 12 matches the outer diameter of the upper suspension cable 6, the slot 12, after being connected to the upper suspension cable 6 through the first connecting through hole 122, is less likely to move left or right on the upper suspension cable 6.

[0057] Furthermore, since most of the end of the evaporation strip 8 is submerged in wastewater, it has a certain weight after being wetted. Also, the width of the buckle 13 of the latch 132 matches the width of the evaporation strip 8. Thus, after the evaporation strip 8 passes through the latch 132, it can be secured within the latch 132 and is not easily detached from it. Simultaneously, since the second connecting through hole 132 of the latch 13 matches the outer diameter of the lower suspension cable 7, the latch 13, after being connected to the lower suspension cable 7 through the second connecting through hole 132, is not easily moved left or right on the lower suspension cable 7.

[0058] In this way, the evaporation strips 8, which are fixed side-by-side on the upper suspension cable 6 and the lower suspension cable 7, are arranged in an inverted V-shape. This inverted V-shape arrangement significantly increases the vertical capillary water absorption height of the evaporation strips 8 from 3cm-6cm to 10cm-15cm, making it possible to use the evaporation strips 8 on the evaporation rack. Simultaneously, the inverted V-shape arrangement allows the siphon water flow inside the evaporation strips 8 to form a perpetual automatic loop under external evaporation conditions. This eliminates the need for additional energy consumption or the addition of extra surfactants or other auxiliary materials, enabling the evaporation strips 8 to continuously absorb water against gravity. This creates numerous vertical evaporation surfaces within the evaporation tank, effectively enhancing the evaporation capacity and significantly improving the evaporation efficiency of the wastewater within the tank.

[0059] Meanwhile, in a preferred embodiment of the present invention, the direction in which the upper suspension cable 6 and the lower suspension cable 7 are arranged parallel to each other is perpendicular to the wind direction of the maximum wind frequency. Thus, the evaporation strips 8, arranged side-by-side on the upper suspension cable 6 and the lower suspension cable 7, also face the wind direction of the maximum wind frequency, maximizing the conversion of wind power into the evaporation capacity of the evaporation strips 8. Under strong winds, this promotes the evaporation of moisture on the evaporation strips 8. Furthermore, the length of the evaporation strips 8 above the liquid surface is 5cm to 15cm on one side, and the length of the evaporation strips 8 below the liquid surface is 50cm on one side. The exposed height of the evaporation strips 8 is limited, and the exposed portion is completely wetted and reliably fixed to prevent the evaporation strips 8 from being blown away or damaged, giving the evaporation rack strong wind resistance.

[0060] Furthermore, the evaporation racks, as independent evaporation units, can be mass-produced in factories. A certain number of evaporation racks can be placed in the evaporation tank according to project needs to achieve the expected evaporation capacity. This flexible approach allows for easy optimization and adjustment of the evaporation capacity of the evaporation tank at any time. The evaporation racks utilize a floating frame structure to automatically raise and lower the evaporation strips as the liquid level in the evaporation tank changes, avoiding potential problems such as the evaporation strips detaching from the liquid surface or insufficient exposure height under extreme conditions.

[0061] In one specific embodiment of the present invention, to improve the corrosion resistance and service life of the evaporation strip 8, the evaporation strip 8 is made of polyester, polypropylene, or polyester nonwoven geotextile with long or short filaments. To ensure durability, the thickness of the evaporation strip 8 is not less than 2.1 mm. Simultaneously, the parallel spacing between the evaporation strips 8 positioned on the upper suspension cable 6 and the lower suspension cable 7 is 5 cm to 20 cm, the width of the evaporation strip 8 is 2 cm to 40 cm, and the length of the evaporation strip 8 is 110 cm to 130 cm.

[0062] This invention provides a method for constructing a wastewater evaporation system for a geothermal mining plant, comprising the following steps: Step 1) Collect the average annual evaporation and rainfall of the hydrometallurgical plant area, the duration of wastewater discharge from the hydrometallurgical plant, the discharge flow rate, and the area of ​​the proposed evaporation pond.

[0063] Step 2) Calculate the number of evaporation strips arranged in the evaporation rack according to the preliminary basic technical parameters of the evaporation rack, and determine the height of the floating frame, the width of the side plate of the floating frame, and the size of the reserved holes of the floating frame through buoyancy calculation.

[0064] The basic technical parameters of the evaporator include the size of the floating frame, the length and width of the evaporation strips, the spacing between parallel evaporation strips, and the lateral spacing of the slots at the top of the evaporation strips.

[0065] Step 3) Based on the empirical formula for the additional evaporation capacity that a single evaporator can provide:

[0066] The additional evaporation capacity that a single evaporator can provide is calculated.

[0067] Where EM represents the additional evaporation capacity that a single evaporator can provide, m 3 / a; n is the number of evaporation strips in a single evaporator, in strips; A is the area of ​​a single evaporation strip, in m². 2 / strip; E is the local evaporation rate, m³ / a; l is the parallel spacing of the evaporation strips, m, with a value ranging from 0.05m to 0.2m; b is the width of the evaporation strip, m, with a value ranging from 0.02m to 0.4m; t is the lateral spacing of the top slots of the evaporation strips, m, with a value ranging from 0.05m to 0.2m; S is the horizontal projected area of ​​the evaporator frame, m². 2 .

[0068] Step 4) Based on the proposed evaporation pond area, wastewater discharge, annual net evaporation, and the additional evaporation capacity that a single evaporator can provide, determine the number of evaporators required for the evaporation pond to form the final evaporation system.

[0069] The following examples illustrate the construction method of a wastewater evaporation system for a geothermal mining hydrometallurgical plant provided by the present invention.

[0070] A geothermal leaching mine in a certain region of Northwest China discharged 16,400 cubic meters of process wastewater from its hydrometallurgical plant. 3 All wastewater will be discharged into an evaporation pond for natural evaporation treatment, achieving zero wastewater discharge. The maximum rainfall at the project site is 860 mm, and the average evaporation is 2970 mm. An evaporation capacity reduction factor of 0.8 is considered. The strongest wind direction and force throughout the year is 45° west of north. The proposed evaporation pond area is 3900 m². 2 .

[0071] 1) Collect basic data for the project area The maximum rainfall at the project site is 860 mm, the average evaporation is 2970 mm, the strongest wind direction and force throughout the year is 45° west of north, and the hydrometallurgical plant discharges 16400 m³ of process wastewater. 3 / a, The proposed evaporation pond has an area of ​​3900m² 2 .

[0072] 2) Preliminary technical parameters of the new evaporation rack To facilitate the fabrication and on-site operation of the evaporator rack, its size should not be too large. The preliminary internal dimensions are planned as 5.0m x 5.0m, with a floating frame side panel width of 0.06m. The evaporation strips will be made of 2.1mm thick polyester filament non-woven geotextile, with a strip width of 5cm, a single-side strip length of 60cm, a strip length protruding 10cm above the water surface on each side, a longitudinal spacing of 5cm between strips, and a transverse spacing of 5cm between the top slots of the strips. Approximately 4800 evaporation strips can be installed within the evaporator rack. Based on buoyancy calculations, the floating frame side panel height is determined to be 0.8m, with the side panel submerged in water at a depth of 0.6m. Holes with equal intervals of 0.12m (height) x 0.36m (width) are pre-drilled at the top of the side panel.

[0073] 3) Determine the additional evaporation capacity provided by a single evaporator. Local natural net evaporation capacity m / a

[0074]

[0075] =86.5m 3 / a 4) Determine the number of evaporation racks The required projected area of ​​the evaporation tank without an evaporation rack is approximately 9720 m². (The calculation is incomplete and requires further context.) 2 Currently, the available construction site area is only 3900m². 2 Its evaporation capacity = (2970-860)÷1000×0.8×3900 = 6583.2m³ 3 / a, the gap between the target evaporation rate and the target evaporation rate = 16400 - 6583.2 = 9816.8m 3 / a. To achieve the target evaporation rate, a certain number of new evaporation racks are designed to be placed in the evaporation tank to form a high-efficiency evaporation system together with the evaporation tank.

[0076] The number of new evaporator racks needed is 9816.8 ÷ 86.5 = 114. Considering a certain margin, the number of new evaporator racks required for the evaporation system is taken as 130.

[0077] 5) Comparison of evaporation capacity between this new evaporation system and traditional evaporation ponds The final location was determined to be 3900m. 2 130 new evaporation racks were installed in the evaporation tank, forming an evaporation acceleration system together with the evaporation tank, which can meet the needs of wastewater evaporation treatment in the immersion metallurgical plant area of ​​this project.

[0078] In this project, the evaporation capacity using the traditional evaporation pond method is 9720 m³. 3 After applying a three-dimensional high-efficiency evaporation system within the evaporation tank, the evaporation capacity reached 17828 m³. 3 / a, the evaporation capacity is increased by nearly 2.0 times. It can be seen that this evaporation system can multiply the evaporation capacity of a limited area evaporation pond without consuming energy or requiring additional additives, which greatly saves land resources and engineering investment, while also effectively reducing the potential pollution range.

[0079] The wastewater evaporation system and its construction method provided by this invention have the following characteristics: 1. The evaporation strips in the evaporation rack of this invention are arranged in an inverted V-shape, which significantly increases the vertical capillary water absorption height of the geotextile evaporation strips from 3cm-6cm to 10cm-15cm, thus making the application of geotextile on the evaporation rack possible. Simultaneously, the inverted V-shape arrangement allows the siphonic water flow inside the evaporation strips to form a perpetual automatic loop under external evaporation conditions, without requiring additional energy or auxiliary materials such as surfactants. This enables the evaporation strips to continuously absorb water against gravity, forming numerous vertical evaporation surfaces within the evaporation tank, thereby effectively enhancing the evaporation capacity of the evaporation tank and greatly improving evaporation efficiency.

[0080] 2. As the evaporation strip in the evaporation rack, the geotextile material is a widely used and excellent geosynthetic material in the engineering field. It has the advantages of high durability, high corrosion resistance, high toughness, high stability, and low cost, and has a service life of up to several decades. Therefore, the evaporation rack of the present invention can be put into use as a permanent facility. Compared with siphon evaporation devices using other fabric materials, it has very obvious technical and economic advantages.

[0081] 3. This invention uses an evaporator as an independent evaporation unit. The evaporator can be mass-produced in the factory. According to the project needs, a certain number of evaporators can be put into the evaporation tank to achieve the expected evaporation capacity. The project implementation method is flexible and convenient to optimize and adjust the evaporation capacity of the evaporation tank at any time. At the same time, the workload of on-site management and maintenance is also very small.

[0082] 4. This invention utilizes a floating frame structure to automatically raise and lower the evaporation strips according to changes in the liquid level of the evaporation tank, avoiding potential problems such as strips detaching from the liquid surface or insufficient elevation under extreme conditions. The length of the evaporation strips on the floating frame is typically 110cm to 130cm, while only 10cm to 25cm of the strips are exposed above the liquid surface and are in a saturated state, with most of them submerged below the liquid surface. Furthermore, the evaporation strips are reliably fixed, giving the entire device strong wind resistance. Simultaneously, ventilation holes are provided in the exposed portion of the floating frame, and the evaporation strips within the floating frame are arranged at intervals facing the direction of the strongest annual wind, maximizing the evaporation efficiency of the strips.

[0083] 5. The wastewater evaporation system provided by this invention has strong adaptability and can be applied to cold regions in winter. The evaporation rack of this invention is made of antifreeze and non-freeze-swelling materials. After freezing in winter, the evaporation pool relies on the reserved volume to temporarily hold the winter waste liquid. After the waste liquid in the evaporation pool thaws in the following year, all the evaporation racks in the evaporation pool will float up on their own and restore their evaporation capacity. The device will not be damaged or its function will be affected by freezing or other reasons.

[0084] 6. In constructing the evaporation system, this invention proposes an empirical formula for the additional evaporation capacity provided by a single evaporator. This formula can be used to preliminarily determine the technical parameters of the evaporator and the number of evaporators that need to be placed in the evaporation tank, providing a relatively effective mathematical solution for the design and application of evaporation systems.

[0085] Compared with the traditional evaporation pond design scheme used in some mining and metallurgical in-situ leaching mines, the wastewater evaporation system for hydrometallurgical plants in in-situ leaching mines provided by this invention can efficiently improve the evaporation efficiency of the evaporation pond, greatly reduce the project's land area and engineering investment, reduce environmental pollution and its impact range, and facilitate the later management of the evaporation facilities.

[0086] Furthermore, compared to the active acceleration technologies for evaporation capacity used in domestic evaporation ponds, such as atomizing devices, heating devices, blowing devices, and combined devices, the evaporation system for wastewater from in-situ leaching mines and hydrometallurgical plants provided by this invention is conducive to large-scale deployment, significantly improves evaporation capacity, has a long service life, requires no energy consumption or additional additives, can be applied in windy and cold winter regions, and is easy to manage on-site. Compared to domestic passive acceleration technologies for evaporation capacity, the evaporation capacity improvement efficiency of the in-situ leaching mine and hydrometallurgical plant wastewater evaporation system provided by this invention can reach over 200%, demonstrating significant efficiency advantages.

[0087] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A wastewater evaporation system for a geothermal mining plant, characterized in that, include: Evaporation tank and multiple evaporation racks floating on the liquid surface of the evaporation tank; The evaporation rack includes a rectangular floating frame composed of four side plates, and ventilation holes are provided on the upper part of the four side plates outside the liquid surface; The floating frame is provided with corner braces at its four corners, and fixed bolts are provided in the middle of the corner braces. Upper fixed cables are connected between the ends of the fixed bolts of two adjacent corner braces at the top, and lower fixed cables are connected between the ends of the fixed bolts of two adjacent corner braces at the bottom. Upper suspension cables are connected in parallel between the upper fixed cables, and lower suspension cables are connected in parallel with the upper suspension cables between the lower fixed cables. An evaporation strip made of porous material is arranged in parallel between the upper and lower suspension cables via an evaporation strip fixing device. The middle part of the evaporation strip is fixed to the upper suspension cable, and the two ends of the evaporation strip are respectively fixed to the two adjacent lower suspension cables below the upper suspension cable. The two ends of the evaporation strip hang down below the liquid surface of the evaporation tank. The direction in which the upper and lower suspended cables are arranged in parallel is perpendicular to the wind direction of the maximum wind frequency, and the parallel evaporation strips face the wind direction of the maximum wind frequency.

2. The wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants according to claim 1, characterized in that, The length of the floating frame is 4.0m to 10.0m, and the width of the floating frame is 4.0m to 6.0m; the thickness of the side plate is 6cm to 25cm, and the height of the side plate is 35cm to 80cm.

3. The wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants according to claim 2, characterized in that, The projection plane of the corner brace is an isosceles right triangle, the length of the right-angled side of the corner brace is 10cm to 80cm, the thickness of the corner brace is 25cm to 70cm, and the corner brace has a through hole in the middle for installing the fixing bolt.

4. The wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants according to claim 3, characterized in that, The fixing bolt includes a nut and a screw. The outer diameter of the nut's thread body matches the inner diameter of the mounting hole. The nut's thread body has a tubular hollow structure and is provided with internal threads. The outer diameter of the screw's thread body matches the inner diameter of the nut's tubular hollow structure and is provided with external threads. The nut is installed in the mounting hole from one side of the bracket, and the screw is screwed to the nut from the other side of the bracket. The nut head and the screw head both have circumferential grooves in the middle of their sides. The nut and the screw are fixedly connected to the upper fixing cable and the lower fixing cable through the grooves.

5. The wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants according to claim 4, characterized in that, The distance between the upper fixed cable and the lower fixed cable is 30cm to 75cm. The upper suspended cables are arranged in parallel with equal intervals of 5cm to 20cm, and the lower suspended cables are arranged in parallel with equal intervals of 5cm to 20cm.

6. The wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants according to claim 5, characterized in that, The thickness of the evaporation strip is not less than 2.1 mm, the parallel spacing between the evaporation strips is 5 cm to 20 cm, the width of the evaporation strip is 2 cm to 40 cm, the length of the evaporation strip is 110 cm to 130 cm, the length of the evaporation strip on one side above the liquid surface is 5 cm to 15 cm, and the length of the evaporation strip on one side below the liquid surface is 50 cm.

7. The wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants according to claim 6, characterized in that: The evaporation strip fixing device includes a slot and a buckle. The centerline of the slot is provided with a first connecting through hole that matches the outer diameter of the upper suspension cable. The slot is connected to the upper suspension cable through the first connecting hole. The outer surface of the slot is provided with a fixing groove whose width matches the width of the evaporation strip. The centerline of the buckle is provided with a second connecting through hole that matches the outer diameter of the lower suspension cable. The buckle is connected to the lower suspension cable through the second connecting through hole. The outer side of the buckle is provided with a locking opening whose width matches the width of the evaporation strip.

8. The wastewater evaporation system for in-situ leaching mines and hydrometallurgical plants according to claim 7, characterized in that: The floating frame is a lightweight hollow rectangular frame structure made by rotational molding. The corner braces and the floating frame are integrally molded. The floating frame and the corner braces are made of high-density polyethylene or linear low-density polyethylene. The fixing bolt is a lightweight hollow structure made by rotational molding, and the fixing bolt is made of high-density polyethylene material; The upper and lower fixing cables are made of ultra-high molecular weight polyethylene fiber or polyester fiber. The upper and lower suspension cables are made of ultra-high molecular weight polyethylene fiber or polyester fiber. The slots and buckles of the evaporation strip fixing device are made of high-density polyethylene. The evaporation strip is made of polyester, polypropylene, or polyester nonwoven geotextile with long or short filaments.

9. A method for constructing a wastewater evaporation system for a geothermal mining plant as described in any one of claims 1-8, characterized in that, Includes the following steps: Collect data on the average annual evaporation and rainfall of the hydrometallurgical plant area, the duration and flow rate of wastewater discharge from the hydrometallurgical plant, and the area of ​​the proposed evaporation pond; The number of evaporation strips arranged inside the evaporation rack is calculated based on the preliminary basic technical parameters of the evaporation rack, and the height of the floating frame, the width of the side plate of the floating frame, and the size of the reserved holes in the floating frame are determined by buoyancy calculation. Based on the empirical formula for the additional evaporation capacity provided by a single evaporator: The additional evaporation capacity that a single evaporator can provide is calculated; Where EM represents the additional evaporation capacity that a single evaporator can provide, m 3 / a; n is the number of evaporation strips in a single evaporator, in strips; A is the area of ​​a single evaporation strip, in m². 2 / strip; E is the local evaporation rate, m³ / a; l is the parallel spacing of the evaporation strips, m, with a value ranging from 0.05m to 0.2m; b is the width of the evaporation strip, m, with a value ranging from 0.02m to 0.4m; t is the lateral spacing of the top slots of the evaporation strips, m, with a value ranging from 0.05m to 0.2m; S is the horizontal projected area of ​​the evaporator frame, m². 2 ; Based on the proposed evaporation pond area, wastewater discharge, annual net evaporation, and the additional evaporation capacity provided by a single evaporator, the number of evaporators required for the evaporation pond is determined, forming the final evaporation system.

10. The method for constructing a wastewater evaporation system for a geothermal mining plant according to claim 9, characterized in that, The basic technical parameters of the evaporator include the size of the floating frame, the length and width of the evaporation strips, the spacing between the parallel evaporation strips, and the lateral spacing of the slots at the top of the evaporation strips.

Images