High-intensity magnetic separation recovery method for uraninite

Abstract

The invention provides a high-intensity magnetic separation recycling method for uraninite. The high-intensity magnetic separation recycling method comprises the following steps that S1, raw ore is ground and screened to form ore pulp; s2, the ore pulp is fed into a high-intensity magnetic separator for magnetic separation, and concentrate 1, middling 1 and tailings 1 are obtained; s3, the middlings 1 and the tailings 1 obtained in the step S2 are fed into a first superconducting magnetic separator for magnetic separation, and concentrates 2, middlings 2 and tailings 2 are obtained; the method has the beneficial effects that the raw ore containing the crystalline uranium ore is subjected to ore grinding and screening, the ore pulp with the fineness meeting the ore dressing requirement is obtained, and then the uranium ore with relatively large particles is separated out through the high-intensity magnetic separator; scavenging the remaining middlings and tailings by using a first superconducting magnetic separator at a higher magnetic induction intensity of 5T-6T so as to recover micro-fine particle uraninite and intergrowth with weak magnetism; and the first superconducting strong magnetic separation middlings are reground, uranium mineral intergrowth is dissociated and then reseparated, and uranium minerals in the middlings are fully recycled.

Description

Technical Field

[0001] The present application belongs to the technical field of uranium ore separation, and specifically relates to a method for high-intensity magnetic separation and recovery of crystalline uranium ore. Background Art

[0002] Crystalline uranium ore is one of the most widely distributed uranium minerals in my country's uranium deposits. Since the 1960s, domestic and foreign scholars have carried out a large number of uranium ore flotation technology studies. It is believed that flotation agents with a collection effect on uranium minerals include sodium oleate, copper iron reagent, copper iron reagent derivatives, chelating collectors containing different functional groups, etc. Although certain research results have been achieved in the flotation of uranium minerals, there are still unfavorable factors such as low technical indicators, high reagent consumption, and environmental unfriendliness. In the existing technology, gravity separation is used to recover uranium minerals in ores. Since crystalline uranium ore is usually embedded in fine particles, the recovery effect is not good. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] In order to solve the above problems, the present application provides a method for high-intensity magnetic separation and recovery of crystalline uranium ore, comprising the following steps:

[0005] S1, grinding and screening the raw ore to form slurry;

[0006] S2, feeding the slurry into a high-intensity magnetic separator for magnetic separation to obtain concentrate 1, middlings 1 and tailings 1;

[0007] S3, feeding the middling ore 1 and the tailings 1 obtained in step S2 into a first superconducting magnetic separator for magnetic separation to obtain a concentrate 2, a middling ore 2 and a tailings 2;

[0008] S4, regrinding the middling ore 2 obtained in step S3 to dissociate the uranium mineral conglomerates, and then feeding the ore into a second superconducting magnetic separator for magnetic separation to obtain concentrate 3 and tailings 3.

[0009] Optionally, the magnetic induction intensity of the first superconducting magnetic separator and the second superconducting magnetic separator is 5T-6T.

[0010] Optionally, before the middlings 1 and tailings 1 are fed into the first superconducting magnetic separator in step S3, it is necessary to mix the steel rod medium and fill it into the first superconducting magnetic separator.

[0011] Optionally, before the middling ore 2 is fed into the second superconducting magnetic separator in S4, it is necessary to mix the steel rod medium and fill it into the second superconducting magnetic separator.

[0012] Optionally, in S1, in the ore pulp formed by grinding and screening the raw ore, the content of -0.074 mm particle size in the ore pulp is 50%-90%.

[0013] Optionally, in the step S4, the -0.074 mm particle size content of the medium ore 2 after grinding is 90%-95%.

[0014] Optionally, in the step S2, the magnetic induction intensity of the high-intensity magnetic separator is 1T-1.5T.

[0015] Optionally, the magnetic induction intensity of the high-intensity magnetic separator is 1T.

[0016] Beneficial Effects

[0017] The embodiment of the present invention provides a high-intensity magnetic separation and recovery method for crystalline uranium ore, which comprises the following steps: grinding and screening the raw ore containing the crystalline uranium ore to obtain a pulp with a fineness that meets the requirements of ore dressing, and then selecting the uranium minerals with relatively large particles by a high-intensity magnetic separator; the remaining middlings and tailings are subjected to scanning and selection by a first superconducting magnetic separator at a higher magnetic induction intensity of 5T-6T to recover the fine-grained crystalline uranium ore and its intergrowths with weak magnetism; the middlings obtained by the first superconducting high-intensity magnetic separation are re-grinded to dissociate the intergrowths of uranium minerals and then re-selected to fully recover the uranium minerals in the middlings. The present invention adopts a superconducting magnetic separator in combination with a conventional high-intensity magnetic separation process to perform high-intensity magnetic separation in steps at different magnetic field intensities, recovers the crystalline uranium ore and the carrier minerals of the crystalline uranium ore, and obtains a crystalline uranium ore concentrate product with a high recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The flowchart of the high-intensity magnetic separation and recovery method of crystalline uranium ore of the present invention is as follows;

[0019] Figure 2 The figure is a flow chart of the first embodiment of the high intensity magnetic separation and recovery method of crystalline uranium ore of the present invention. DETAILED DESCRIPTION

[0020] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0024] See also Figure 1 As shown, according to an embodiment of the present application, a method for high-intensity magnetic separation and recovery of crystalline uranium ore is provided, comprising the following steps:

[0025] S1, grinding and screening the raw ore to form slurry;

[0026] Specifically, the raw ore containing crystalline uranium ore and water are added to the grinding mill in a specific ratio. The grinding mill is filled with media such as steel balls or steel rods. With its high hardness and regular spherical shape, the steel balls continuously impact and grind the ore under the centrifugal force and friction generated by the rotation of the grinding mill, gradually reducing its particle size; the steel rods, with their unique long strip structure, can not only impact and crush the ore during grinding, but also produce strong grinding and extrusion effects. They are especially suitable for processing ores with larger particle sizes and higher hardness, and can effectively avoid over-crushing and ensure the uniformity of the particle size of the grinding products.

[0027] In the mill, the ore is fully mixed with steel balls or steel rods and water. As the mill continues to operate, the ore is gradually crushed into fine particles under the continuous impact, grinding and squeezing of the medium. After sufficient grinding, the slurry is discharged from the mill. At this time, the particle size distribution of the discharged slurry is relatively wide, and further screening is required to determine whether the particle size after grinding meets the requirements.

[0028] Next, the slurry enters the fine screen for screening. Fine screens usually use equipment such as vibrating screens or high-frequency fine screens. These devices use vibrations of different frequencies to make the slurry flow quickly on the screen surface, and at the same time separate the particles in the slurry according to the size of the screen aperture. Through the screening operation, the particle size of the ore after grinding can be accurately determined.

[0029] In the beneficiation process of crystalline uranium ore, the particle size requirement for the pulp after grinding at this stage is -0.074mm particle size content of 50%-90%. When the particle size reaches this standard, it means that the ore has been ground to an appropriate degree, which not only avoids the failure of useful minerals to be fully dissociated due to too coarse particle size, affecting the subsequent separation effect; it also prevents problems such as increased energy consumption, increased equipment wear and serious mineral mudification caused by excessive grinding, which is conducive to the next step of magnetic separation and other beneficiation operations, and lays a solid foundation for improving the recovery rate and concentrate grade of crystalline uranium ore. If the particle size does not meet the requirements, it is necessary to adjust the operating parameters of the mill, such as changing the ratio of steel balls or steel bars, adjusting the grinding time, optimizing the feeding speed, etc., and re-grinding and screening until the specified particle size standard is reached.

[0030] S2, feeding the slurry into a high-intensity magnetic separator for magnetic separation to obtain concentrate 1, middlings 1 and tailings 1;

[0031] Specifically, when the particle size of the ore pulp meets the requirement of 50%-90% of the -0.074mm particle size, it enters the high-intensity magnetic separation. A special conveying device, such as a slurry pump, is used to convey the ore pulp to the interior of the high-intensity magnetic separator at a stable and uniform flow rate.

[0032] The magnetic induction intensity inside the high-intensity magnetic separator is set to 1T-1.5T. Under this specific magnetic field strength, the mineral particles in the slurry will move in different trajectories according to the differences in the magnetic properties of different minerals. For those minerals that are relatively weak in magnetism but can still respond in this magnetic field environment, they will be affected by the magnetic force and gradually gather in areas with higher magnetic field intensity. These weakly magnetic minerals attracted and gathered by the magnetic field are the concentrates we need1. They are separated from the magnetic separator through specific collection devices, such as scrapers or flushing water, and enter the subsequent concentrate processing process.

[0033] However, under this magnetic field strength, some minerals cannot be effectively adsorbed and collected due to weak or almost non-magnetic magnetism, and these minerals form middlings 1 and tailings 1. Although middlings 1 and tailings 1 have not been successfully separated for the time being, they still contain a certain amount of valuable minerals, so they will be combined together and prepared to enter the next processing flow.

[0034] S3, feeding the middling ore 1 and the tailings 1 obtained in step S2 into a first superconducting magnetic separator for magnetic separation to obtain a concentrate 2, a middling ore 2 and a tailings 2;

[0035] Specifically, after the high-intensity magnetic separator completes the preliminary magnetic separation, the middlings 1 and tailings 1 are collected uniformly, and the slurry is smoothly and evenly fed into the first superconducting magnetic separator through a slurry pump and a conveying pipeline. During the conveying process, the flow rate and pressure of the slurry must be strictly controlled to ensure that it can flow stably in the superconducting magnetic separator to avoid poor mineral separation effects due to excessive flow rate or unstable pressure.

[0036] The No.1 superconducting magnetic separator is an advanced mineral processing equipment that uses superconducting technology to generate a strong and stable magnetic field. Before feeding the slurry, technicians will conduct a comprehensive inspection and debugging of the superconducting magnetic separator to ensure that its parameters are in the best state. The superconducting magnet of the No.1 superconducting magnetic separator needs to be cooled to an extremely low temperature in advance to reach a superconducting state, so that it can produce a high-intensity magnetic induction intensity of 5T-6T. At the same time, steel rod media with suitable diameters will be mixed and filled into the separation space of the magnetic separator in a specific way and density. These steel rod media can enhance the magnetic field gradient and improve the capture ability of weakly magnetic minerals.

[0037] When the ore pulp enters the first superconducting magnetic separator, it is in a high-intensity magnetic field environment. Under the magnetic induction intensity of 5T-6T, various mineral particles in the ore pulp are subjected to different degrees of magnetic force. For those difficult-to-select weakly magnetic minerals that have not been selected in the previous strong magnetic separation process, they will move to the area with higher magnetic field gradient under the attraction of strong magnetic force and be adsorbed on the surface or around the steel rod medium.

[0038] As the slurry continues to flow in the magnetic separator, the mineral particles gradually separate. Finally, the adsorbed difficult-to-select weakly magnetic minerals form concentrate 2, which is discharged from the magnetic separator through a specific unloading device. However, there is still a part of the minerals with relatively weaker or almost non-magnetic magnetism, forming middlings 2 and tailings 2. Middlings 2 may still contain a certain amount of useful minerals that need further processing; tailings 2 is the waste remaining after this magnetic separation, which will be transported to the tailings pond for storage or further processing.

[0039] S4, regrinding the middling ore 2 obtained in step S3 to dissociate the uranium mineral conglomerates, and then feeding the ore into a second superconducting magnetic separator for magnetic separation to obtain concentrate 3 and tailings 3.

[0040] Specifically, after the magnetic separation operation of the first superconducting magnetic separator is completed, the separated medium ore 2 is collected and stored. The storage tank is equipped with a stirring device to maintain the uniformity of the medium ore 2 slurry, prevent the mineral particles from settling, and provide stable feeding conditions for subsequent grinding operations.

[0041] The middling ore 2 still contains a certain amount of uranium minerals associated with other gangue minerals, and these associated bodies cannot be effectively recovered in the previous magnetic separation process. In order to achieve monomer dissociation of these associated uranium minerals, the middling ore 2 in the storage tank is pumped to the grinding equipment. The grinding equipment usually uses a ball mill or a rod mill, which is filled with grinding media of different specifications. The particle size of the product after grinding needs to be controlled within an appropriate range to ensure that the uranium minerals and gangue minerals are separated as much as possible.

[0042] When the grinding operation is completed and it is confirmed that the slurry has achieved the expected dissociation effect, the ground slurry is transported to the second superconducting magnetic separator for reselection. This second superconducting magnetic separator also needs to be debugged in advance, and the magnetic induction intensity is accurately set between 5T-6T. In this high-intensity magnetic field environment, the uranium mineral particles in the medium ore 2 are subjected to strong magnetic force. Since the previous grinding dissociated the uranium mineral monomers, they can be captured more effectively by the magnetic field at this time. As the slurry flows in the magnetic separator, the uranium minerals move to the magnetic field concentration area and are eventually collected as concentrates, thereby greatly improving the uranium recovery rate. Through this re-grinding and re-selection process of the medium ore 2, the uranium resources in the ore can be deeply excavated, resource waste can be reduced, and the economic benefits and resource utilization rate of the entire beneficiation process can be improved.

[0043] Optionally, the magnetic induction intensity of the first superconducting magnetic separator and the second superconducting magnetic separator is 5T-6T.

[0044] Optionally, before the middlings 1 and tailings 1 are fed into the first superconducting magnetic separator in step S3, it is necessary to mix the steel rod medium and fill it into the first superconducting magnetic separator.

[0045] Optionally, before the middling ore 2 is fed into the second superconducting magnetic separator in S4, it is necessary to mix the steel rod medium and fill it into the second superconducting magnetic separator.

[0046] Optionally, in S1, in the ore pulp formed by grinding and screening the raw ore, the content of -0.074 mm particle size in the ore pulp is 50%-90%.

[0047] Optionally, in the step S4, the -0.074 mm particle size content of the medium ore 2 after grinding is 90%-95%.

[0048] Optionally, in the step S2, the magnetic induction intensity of the high-intensity magnetic separator is 1T-1.5T.

[0049] Optionally, the magnetic induction intensity of the high-intensity magnetic separator is 1T.

[0050] Example 1

[0051] See also Figure 2As shown in the figure, the crystalline uranium ore with a raw uranium grade of 0.035% was ground. The goal of grinding is to make the ore reach a specific fineness. This time, the raw ore was ground to a fineness of -0.074mm, accounting for 60%. The grinding process uses grinding equipment, such as a ball mill or a rod mill, to allow the ore to fully contact and collide with the grinding medium. In this process, the ore is gradually crushed into fine particles, which on the one hand causes the initial dissociation of uranium minerals from gangue minerals, and on the other hand creates good particle size conditions for subsequent magnetic separation. Because the appropriate particle size allows uranium minerals to better respond to magnetic field forces during magnetic separation, improving separation efficiency.

[0052] The ground slurry is transported to the XCSQ-50×70 high-intensity magnetic separator for conventional high-intensity magnetic separation. The high-intensity magnetic separator operates in an environment with a magnetic induction intensity of 1T-1.5T, but the magnetic induction intensity is set to 1.0T during actual sorting. Under this magnetic field intensity, minerals with strong magnetism are affected by magnetic force and move to areas with higher magnetic field gradients, thereby separating from minerals with weaker or no magnetism. After this stage of magnetic separation, concentrate 1 with a yield of 11.53% was successfully obtained, the uranium grade of concentrate 1 was significantly increased to 0.214%, and the uranium recovery rate reached 70.64%. Most of the uranium-containing minerals with strong magnetism were effectively enriched in concentrate 1, laying the foundation for subsequent further recovery.

[0053] The remaining middlings 1 and tailings 1 after conventional strong magnetic separation contain some uranium-containing minerals with weak magnetism but still worth recovering. In order to further improve the recovery rate of uranium, these strong magnetic tailings are sent to the first superconducting magnetic separator. At this time, steel rod media with diameters of 1.5mm and 2.0mm are mixed and filled into the first superconducting magnetic separator. Steel rod media of different diameters can form complex and diverse magnetic field gradients in the magnetic field, enhancing the ability to capture weakly magnetic minerals. Superconducting strong magnetic separation is carried out under the condition of a magnetic induction intensity of 5T. The strong magnetic field force can effectively separate weakly magnetic uranium-containing minerals that were difficult to capture in the conventional strong magnetic separation stage. In this stage, superconducting strong magnetic separation concentrate 2 with a yield of 7.51%, middlings 2 with a yield of 17.29%, and tailings 2 with a yield of 63.67% were obtained. The uranium grade of tailings 2 was greatly reduced to 0.0032%, indicating that most of the valuable uranium minerals have been separated;

[0054] There are still some inter-growth uranium-containing minerals in the intermediate ore 2 produced in the previous stage. In order to dissociate these inter-growth uranium mineral monomers for further recovery, the intermediate ore 2 is ground to a fineness of -0.074mm, accounting for 94%. Then, the second superconducting magnetic separator filled with a mixed medium of steel rods with a diameter of 1.5mm and 2.0mm is used again to carry out superconducting strong magnetic separation under the condition of a magnetic induction intensity of 5T. After magnetic separation, a concentrate 3 with a yield of 0.56% and a tailing 3 with a yield of 16.73% are obtained. The uranium resources in the intermediate ore 2 are further excavated, and the overall uranium recovery rate is improved.

[0055] Through the above series of conventional high-intensity magnetic separation and superconducting high-intensity magnetic separation processes, the total yield of uranium in the three concentrates reached 19.60%, the total recovery rate was as high as 92.45%, and the uranium grade of the concentrate was 0.165%. This series of data fully proves the high efficiency of the magnetic separation and recovery process. From the initial low-grade ore, after multiple stages of magnetic separation and regrinding, the efficient enrichment and recovery of uranium resources are achieved, which not only improves the utilization rate of uranium ore resources and reduces resource waste, but also provides a more reliable raw material guarantee for the nuclear energy industry.

[0056] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A method for recovering crystalline uranium ore by high-intensity magnetic separation, characterized in that: The following steps are involved: S1, grinding and screening the raw ore to form slurry; S2, feeding the slurry into a high-intensity magnetic separator for magnetic separation to obtain concentrate 1, middlings 1 and tailings 1; S3, feeding the middling ore 1 and the tailings 1 obtained in step S2 into a first superconducting magnetic separator for magnetic separation to obtain a concentrate 2, a middling ore 2 and a tailings 2; S4, regrinding the middling ore 2 obtained in step S3 to dissociate the uranium mineral conglomerates, and then feeding the ore into a second superconducting magnetic separator for magnetic separation to obtain concentrate 3 and tailings 3.

2. The high-intensity magnetic separation recovery method for crystalline uranium ore according to claim 1, characterized in that: The magnetic induction intensity of the first superconducting magnetic separator and the second superconducting magnetic separator is 5T-6T.

3. The high-intensity magnetic separation recovery method for crystalline uranium ore according to claim 1, characterized in that: Before the middlings 1 and tailings 1 are fed into the first superconducting magnetic separator in step S3, the steel rod medium needs to be mixed and filled into the first superconducting magnetic separator.

4. The high-intensity magnetic separation recovery method for crystalline uranium ore according to claim 1, characterized in that: Before the middling ore 2 is fed into the second superconducting magnetic separator in S4, the steel rod medium needs to be mixed and filled into the second superconducting magnetic separator.

5. The high-intensity magnetic separation recovery method for crystalline uranium ore according to claim 1, characterized in that: In S1, in the ore pulp formed by grinding and screening the raw ore, the content of -0.074 mm particle size in the ore pulp is 50%-90%.

6. The high-intensity magnetic separation recovery method for crystalline uranium ore according to claim 1, characterized in that: In the step S4, the -0.074 mm particle size content of the medium ore 2 after grinding is 90%-95%.

7. The high-intensity magnetic separation recovery method for crystalline uranium ore according to claim 1, characterized in that: In the step S2, the magnetic induction intensity of the high-intensity magnetic separator is 1T-1.5T.

8. The high-intensity magnetic separation recovery method for crystalline uranium ore according to claim 7, characterized in that: The magnetic induction intensity of the high-intensity magnetic separator is 1T.

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