Method for improving uranium ore leaching rate

Abstract

The invention discloses a method for improving the leaching rate of uranium ore, which can perform controllable shock wave operation in a well or a small number of wells to unblock and increase gaps in a mining area, and shock waves impact off fine particulate matters such as sand, rock powder and the like and precipitated blockages such as chemical precipitates such as calcium, magnesium, aluminum and the like attached in rock stratum gaps of the uranium ore, so that the leaching rate of the uranium ore is improved. Fine particles attached to the filter screen are vibrated off and peeled off; the in-situ leaching liquid is injected after being heated to a certain temperature, and the heated in-situ leaching liquid flows into the uranium mine rock stratum gap. The method improves the leaching rate of uranium ore, can operate at any time for a long time, achieves a continuous effect, improves the uranium well oil extraction efficiency by 10% or above, has a wide application prospect, and has great significance for improving uranium ore strategic material storage in the nuclear industry in China.

Description

Technical Field

[0001] The invention belongs to the technical field of uranium mining and relates to a method for improving the leaching rate of uranium ore. Background Art

[0002] In the current uranium mining process, the leaching efficiency of uranium ore is low. One of the main reasons is that the filter screen in the uranium ore extraction well is blocked by fine particles such as sand and rock powder and chemical precipitates such as calcium, magnesium, and aluminum, which hinders the fluidity of the in-situ leaching solution. The main solution to unblocking in the current in-situ leaching of uranium is well washing. The well washing methods include air compressor well washing, piston well washing, chemical agent well washing, foam well washing, etc. Air compressors and piston well washing are commonly used; or chemical agents are used in combination with them.

[0003] The disadvantages of using well flushing to clear blockages are that air compressor well flushing lasts for half a month, and piston well flushing lasts for 1-2 months, which is long, inefficient, and costly. Chemical well flushing is mainly for chemical blockages, but it usually requires soaking, takes a long time to process, and is prone to corroding equipment. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a method for improving the leaching rate of uranium ore, which solves the problems of low efficiency and high cost in the extraction process and low uranium content in the extracted in-situ leaching liquid in the prior art.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for improving the leaching rate of uranium ore, comprising the following operations:

[0007] a. Shock wave unblocking and gap increasing:

[0008] The controllable shock wave generator is suspended and lowered to the filter in the pumping well or injection well, and is located in the middle and / or upper end or lower end of the filter; the controllable shock wave generator is started, and the shock wave generated by the generator peels off the attachments on the filter to restore the filtering performance; and as the shock wave propagates, the blockage is removed and the gap is increased in the uranium mining area including the pumping well and the injection well;

[0009] After the controlled shock wave operation is completed, the controlled shock wave generator is lifted out of the pumping well or injection well, and then the well is completed;

[0010] b. Change the ground leaching liquid temperature:

[0011] A heating device is added to the in-situ leaching liquid storage tank, or a heating tank connected to the injection well is set up to heat the in-situ leaching liquid to be injected to 30-50°C to reduce the viscosity of the leaching liquid and enhance its fluidity. The in-situ leaching liquid is pressurized and transported to the injection well through a pipeline through a pressurizing device. The in-situ leaching liquid flows through a filter into the cracks in the uranium ore rock formation to accelerate the dissolution of uranium minerals. The in-situ leaching liquid is then lifted to the surface through a pumping well.

[0012] The controllable shock wave generator is suspended and lowered / raised by a cable, and the cable is wound around a winch, a ground pulley and a ceiling pulley arranged beside the pumping well in sequence; the winch rotates to put the controllable shock wave generator into or raise it into the pumping well or injection well.

[0013] The controllable shock wave generator is provided with 0.25-2.5g of energetic material, and the shock wave generated by the controllable shock wave generator cannot expand the diameter of the filter screen or cause damage.

[0014] The controllable shock wave generator is respectively arranged at a plurality of placement points;

[0015] If there are more than 3 placement points, the controllable shock wave generators are set 1 to 3 meters apart from each other;

[0016] If the placement points are 1 to 3, the controllable shock wave generators are set 2 to 3 meters apart from each other.

[0017] A plurality of injection wells are arranged beside the pumping well, and the pumping wells and the injection wells are in a plum blossom shape as a whole; a controllable shock wave generator is placed in the injection well.

[0018] The interval between two adjacent controllable shock wave operations is at least 6 months.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] The method for improving the leaching rate of uranium ore provided by the present invention can perform controllable shock wave operation in an injection well or a pumping well to unblock the filter. The shock wave can impact, vibrate and peel off fine particles such as sand and rock powder attached to the filter net, as well as chemical precipitates such as calcium, magnesium and aluminum, so as to restore the filtering performance. The operation can be maintained for at least half a year. Compared with the existing well washing and unblocking, the operation is simple, and has the advantages of short operation time, high efficiency and low cost. Compared with chemical washing, it does not require soaking, has a short processing time and does not affect the equipment in the well.

[0021] The method for improving the leaching rate of uranium ore provided by the present invention is to further heat the in-situ leaching liquid to a certain temperature before injecting it on the basis of the shock wave operation. Compared with the existing method of directly injecting the in-situ leaching liquid into the injection well, the in-situ leaching liquid is heated and then flows into the cracks of the uranium ore rock layer, so as to accelerate the dissolution rate of the uranium mineral and make the uranium more effectively leached from the ore into the solution; at the same time, the appropriate temperature can reduce the viscosity of the leaching liquid, enhance its fluidity, facilitate the seepage of the leaching liquid in the ore layer, better contact with the uranium ore, dissolve the uranium element in the ore, and then be lifted out of the ground through the pumping well, so as to increase the uranium content in the extracted in-situ leaching liquid.

[0022] The method for improving the leaching rate of uranium ore provided by the present invention can be operated for a long time and at any time to achieve a sustained effect. The oil production efficiency of the uranium well is improved by more than 10%, the benefits of the ore bed can be increased, and the service life of the mine can be improved; the cost is effectively reduced and the leaching rate of uranium ore is improved, and the method has broad application prospects, which is of great significance for improving the strategic uranium material reserves for my country's nuclear industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the process for improving the leaching rate of uranium ore according to the present invention.

[0024] Among them, 1 is a winch, 2 is a ground pulley, 3 is a ceiling pulley, 4 is an armored cable, 5 is a controllable shock wave generator, 6 is a filter, 7 is a plugging object, 8 is a heatable ground immersion liquid box, 9 is ground immersion liquid, 10 is a liquid injection filter, 11 is gravel, and 12 is a formation. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the embodiments, which are intended to explain the present invention rather than to limit it.

[0026] See also Figure 1 The present invention provides a method for improving the leaching rate of uranium ore, comprising the following operations:

[0027] a. Shock wave unblocks the filter:

[0028] The controllable shock wave generator is suspended and lowered to the filter in the pumping well or injection well, and is located in the middle and / or upper end or lower end; the controllable shock wave generator is started, and the shock wave generated by the generator peels off the attachments on the filter and restores the filtering performance; and as the shock wave propagates, the strata in the uranium mining area near the filter in the pumping well or injection well are unblocked and the gap is increased;

[0029] After the controlled shock wave operation is completed, the controlled shock wave generator is lifted out of the well and then the well is completed;

[0030] b. Change the ground leaching liquid temperature:

[0031] A heating device is added to the in-situ leaching liquid storage tank, or a heating tank connected to the injection well is set up to heat the in-situ leaching liquid to be injected to 30-50°C, and the in-situ leaching liquid is pressurized and transported to the injection well through a pipeline by a pressurizing device; the in-situ leaching liquid flows into the cracks of the uranium ore rock layer through a filter, accelerating the dissolution rate of the uranium mineral, so that uranium is more effectively leached from the ore into the solution; the appropriate temperature can reduce the viscosity of the leaching liquid, enhance its fluidity, and facilitate the seepage of the leaching liquid in the ore layer, so as to better contact with the uranium ore and dissolve the uranium element in the ore. The in-situ leaching liquid is then lifted to the surface through the pumping well, thereby increasing the uranium content in the extracted in-situ leaching liquid.

[0032] Furthermore, the controllable shock wave generator is provided with 0.25 to 2.5 g of energetic material (the amount of energetic material is adjusted according to geological conditions), and the shock wave generated by the controllable shock wave generator cannot expand the diameter of the filter or damage the filter screen.

[0033] There are 2 to 3 or more controllable shock wave generator placement points, and the number of controllable shock wave generators is adjusted according to geological conditions, with one controllable shock wave generator being set at one placement point;

[0034] If there are more than 3 placement points, the controllable shock wave generators are set 1 to 3 meters apart from each other;

[0035] If the placement points are 1 to 3, the controllable shock wave generators are set 2 to 3 meters apart from each other.

[0036] The interval between two operations of the controllable shock wave operation is at least 6 months, while the existing well flushing maintenance time is an average of 3 months.

[0037] Specific examples are given below.

[0038] Example 1

[0039] A method for improving the leaching rate of uranium ore, comprising the following operations:

[0040] 1) Controllable shock wave to remove blockage and increase clearance of pumping wells and injection wells in low leaching areas

[0041] The pumping well and the injection well are in the shape of a plum blossom as a whole. A ground device is arranged between the pumping well and the injection well, including a winch 1, a ground pulley 2, and a top pulley 3. An armored cable 4 (7-core cable) is wound around the winch, the ground pulley, and the top pulley in sequence. The winch rotates to put a controllable shock wave generator 5 (model YF-01) into or out of the well.

[0042] Specifically, the controllable shock wave generator is provided with 1g of energetic material, and two controllable shock wave generators are installed on the armored cable 4;

[0043] Lower the controllable shock wave generator into the well (either pumping well or injection well) through the armored cable to the filter position, and adjust the position to the upper end and the lower end of the filter;

[0044] Press the start button on the ground, and the control signal is transmitted to the controllable shock wave generator underground through a 7-core cable. The 220V voltage is inverted into high-voltage discharge, releasing plasma to directly drive the energetic material to generate high-intensity shock waves, which vibrate off the fine particles attached to the filter net; the shock wave impacts the fine particles such as sand and rock powder attached to the cracks in the uranium ore rock layer and chemical precipitates such as calcium, magnesium, and aluminum.

[0045] After the controlled shock wave operation, the device is lifted out of the wellbore and the well is completed.

[0046] 2) Increase the reaction rate by changing the immersion liquid temperature

[0047] The leaching liquid is heated in a heating tank. When it is heated to 40°C, the valve is opened, the pressure pump is started, and the leaching liquid is pressurized and transported to the injection well through a pipeline. The existing leaching liquid can be used as the leaching liquid. The leaching liquid flows into the cracks of the uranium ore rock formation through a filter. The leaching agent reacts chemically with the mineral to dissolve the uranium element in the ore, and is lifted to the surface through the pumping well. After a series of separation treatments, the metallic uranium is recovered.

[0048] The method for improving the leaching rate of uranium ore provided by the present invention can be operated for a long time and at any time to achieve a sustained effect. The oil production efficiency of the uranium well is improved by more than 10%, the benefits of the ore bed can be increased, and the service life of the mine can be improved; the cost is effectively reduced and the leaching rate of uranium ore is improved, and the method has broad application prospects, which is of great significance for improving the strategic uranium material reserves for my country's nuclear industry.

[0049] The above embodiments are preferred examples for implementing the present invention, and the present invention is not limited to the above embodiments. Any non-essential additions and substitutions made by those skilled in the art based on the technical features of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for improving the leaching rate of uranium ore, characterized in that: The following operations are included: a. Shock wave unblocking and gap increasing: The controllable shock wave generator is suspended and lowered to the filter in the pumping well or injection well, and is located in the middle and / or upper end or lower end of the filter; the controllable shock wave generator is started, and the shock wave generated by the generator peels off the attachments on the filter to restore the filtering performance; and as the shock wave propagates, the blockage is removed and the gap is increased in the uranium mining area including the pumping well and the injection well; After the controlled shock wave operation is completed, the controlled shock wave generator is lifted out of the pumping well or injection well, and then the well is completed; b. Change the ground leaching liquid temperature: Add a heating device to the in-situ leaching liquid storage tank, or set up a heating tank connected to the injection well to heat the in-situ leaching liquid to be injected to 30-50°C to reduce the viscosity of the leaching liquid and enhance its fluidity; The leaching liquid is pressurized and transported to the injection well through a pipeline by a pressure-boosting device. The leaching liquid flows into the cracks of the uranium ore rock formations through a filter to accelerate the dissolution of the uranium minerals. The leaching liquid is then lifted to the surface through a pumping well.

2. The method for improving the leaching rate of uranium ore according to claim 1, characterized in that: The controllable shock wave generator is suspended and lowered / raised by a cable, and the cable is wound around a winch, a ground pulley and a ceiling pulley arranged beside the pumping well in sequence; the winch rotates to put the controllable shock wave generator into or raise it into the pumping well or injection well.

3. The method for improving the leaching rate of uranium ore according to claim 1, characterized in that: The controllable shock wave generator is provided with 0.25-2.5g of energetic material, and the shock wave generated by the controllable shock wave generator cannot expand the diameter of the filter screen or cause damage.

4. The method for improving the leaching rate of uranium ore according to claim 3, characterized in that: The controllable shock wave generator is respectively arranged at a plurality of placement points; If there are more than 3 placement points, the controllable shock wave generators are set 1 to 3 meters apart from each other; If the placement points are 1 to 3, the controllable shock wave generators are set 2 to 3 meters apart from each other.

5. The method for improving the leaching rate of uranium ore according to claim 1, characterized in that: A plurality of injection wells are arranged beside the pumping well, and the pumping wells and the injection wells are in a plum blossom shape as a whole; a controllable shock wave generator is placed in the injection well.

6. The method for improving the leaching rate of uranium ore according to claim 1, characterized in that: The interval between two adjacent controllable shock wave operations is at least 6 months.

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