Mineral separation and tailing discarding process for volcanic rock type uranium ore
By combining heavy liquid sorting and heavy medium cyclone sorting, the problem of insufficient ore dressing technology of volcanic rock-type uranium ore is solved, and efficient tailing and high-grade uranium ore recovery is achieved, reducing production costs and improving development and utilization efficiency.
Patent Information
- Application Number
- CN202411825395.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-02-28
AI Technical Summary
The ore dressing technology of volcanic rock-type uranium ore has not yet been made, resulting in low efficiency and high cost of uranium ore development and utilization. The existing radioactive sorting methods are extensive, resulting in serious metal losses in tailings and inconvenient equipment maintenance.
The combination of heavy liquid sorting and heavy medium cyclone sorting is adopted to improve the grade of uranium ore through density gradient sorting and particle size level grading, and use heavy medium to perform tailings in the cyclone to reduce the process processing volume of subsequent water smelting extraction.
It has achieved the abandonment of large amounts of tailings under coarse particle conditions, improve ore grade, reduce uranium extraction costs, and improve development and utilization efficiency. It has high sorting accuracy, pure physical sorting is free from drug contamination, and simple operation.
Smart Images
Figure CN119525006A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a volcanic rock type uranium ore dressing and tailings discarding process, belonging to the technical field of uranium mining and metallurgy. Background Art
[0002] Hard rock uranium ore resource reserves account for 49% of my country's total natural uranium reserves, while volcanic uranium ore reserves account for 24% of the country's uranium reserves. The geological characteristics of volcanic uranium deposits are large changes in ore bodies, often with branching and complex phenomena, extremely uneven uranium mineralization, and alternating high and low uranium grades with huge differences. Since most ore bodies are small and scattered, the depletion rate is high during mining, there is a lot of waste rock mixed in, the uranium grade of the ore is low, and the cost of direct hydrometallurgical extraction of uranium is high, resulting in most of the hard rock uranium mines in China currently being in a loss-making state of suspension.
[0003] The existing mineral processing technology was developed in the 1980s. It used the natural radioactivity of uranium ore to separate the tailings of large waste rocks. However, radioactive sorting was relatively extensive, and there was a lot of metal loss in the tailings. In addition, the equipment was inconvenient to operate and maintain, so it was abandoned not long after it was put into production. Other mineral processing technologies for volcanic rock uranium deposits have not made any breakthroughs, and the development and utilization of this type of uranium deposits has not been effectively solved. Summary of the invention
[0004] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a volcanic rock type uranium ore dressing and tailings discarding process. The present invention adopts a simple and effective uranium ore dressing technology. First, heavy liquid separation is used to determine the minimum density of uranium grade ≥0.02, and then the ore is classified again and heavy liquid separation is carried out to obtain the product yield of uranium grade ≥0.022 of ore products of different particle size levels. The cyclone is continued to be used in the presence of heavy medium to discard the waste rock tailings through centrifugal force, so as to discard a large amount of tailings under coarse particle conditions and improve the ore grade. The method of the present invention can also reduce the process processing amount of subsequent uranium hydrometallurgical extraction, thereby achieving the purpose of reducing production costs and improving development and utilization benefits.
[0005] In order to achieve the above object, the first aspect of the present invention is to provide a volcanic uranium ore dressing tailings discarding process, the process comprising the following steps: (1) Desludging: The volcanic uranium ore is crushed and then desludged to obtain ore particles with a particle size of -20 mm to +0.56 mm and ore mud with a particle size of -0.56 mm; (2) First heavy liquid separation: density step is 0.01~0.07g / cm 3The first batch of heavy liquids with different density gradients are used to perform heavy liquid separation on ore particles with a particle size range of -20 mm to +0.56 mm to obtain ore products with different density levels, and the uranium grades of the ore products with different density levels are analyzed respectively to determine the lowest density A with a uranium grade ≥ 0.02; The minimum density of the first batch of heavy liquid is 2.4-2.55 g / cm 3 ; (3) Ore classification: the ore particles with a size of -20 mm to +0.56 mm obtained in step (1) are screened into at least three material grades to obtain ores of different particle size grades; (4) Second heavy liquid separation: Prepare a second batch of heavy liquids with three different density gradients. In the second batch of heavy liquids, the density of the second heavy liquid I is ≤ (A-0.05) g / cm 3 , the density of the second heavy liquid II is (A±0.03) g / cm 3 , the density of the second heavy liquid III ≥ (A + 0.05) g / cm 3 ; The second batch of heavy liquid is used to perform heavy liquid separation on the ores of different particle sizes to obtain ore products of different particle sizes and density levels, and the uranium grade and yield of the ore products of different particle sizes and density levels are analyzed respectively to determine the product yield B of the ores of each particle size level with a uranium grade ≥ 0.022; (5) Heavy medium separation: ores of different particle sizes are subjected to heavy medium cyclone separation, and the parameters of the heavy medium cyclone separation are controlled so that the concentrate yield of heavy medium separation of ores of each particle size grade is (B±20)%; (6) Magnetic separation: The concentrates and tailings of each particle size obtained by heavy medium cyclone separation are subjected to weak magnetic separation, and the heavy medium is recovered to obtain the final concentrate and final tailings respectively.
[0006] The present invention divides the ore particles of -20mm~+0.56mm into at least three particle size levels. Too many particle size levels will increase the number of sorting series, and too few particle sizes will lead to a too wide particle size range, mutual influence between large particles and small particles, and deterioration of separation technical indicators. In the present invention, there is more ore mud in the -0.56mm ore, which is not suitable for heavy medium separation and needs to be processed separately or directly enter the uranium leaching process as a concentrate.
[0007] In a preferred solution, the ore particles of -20 mm to +0.56 mm are screened into three material grades, and ores of -20 mm to +8 mm, -8 mm to +3.2 mm, and -3.2 mm to +0.56 mm are obtained respectively.
[0008] In a more preferred solution, the ore particles of -20 mm to +0.56 mm are screened into 4 particle sizes, and ores of -20 mm to +8 mm, -8 mm to +3.2 mm, -3.2 mm to +1.25 mm, and -1.25 mm to +0.56 mm are obtained respectively. The inventors found that under this condition, the ore dressing efficiency can be improved. The inventors found that the more the number of particle sizes screened, the smaller the size difference between the largest particle and the smallest particle in a single particle size level, the smaller the effect of particle size on the sorting effect, and the largest particle size is 2.2 to 2.7 times the particle size of the smallest particle size.
[0009] In a preferred embodiment, the density of the second heavy liquid I is (A-0.1~A-0.05) g / cm 3 , the density of the second heavy liquid II is (A±0.03) g / cm 3 , the density of the second heavy liquid III is (A+0.05~A+0.1) g / cm 3 .
[0010] In a preferred embodiment, the first heavy liquid and the second heavy liquid are both sodium polytungstate heavy liquids.
[0011] In a preferred embodiment, the heavy medium used in the heavy medium cyclone separation is ferrosilicon powder with a particle size of <0.05 mm and an iron content of >80%.
[0012] In a more preferred embodiment, the specific gravity of the heavy medium liquid used in the heavy medium cyclone separation is 1.5-3.5 g / cm 3 .
[0013] In a preferred solution, the parameters of the heavy medium cyclone separation include: specific gravity of the heavy medium liquid and feed pressure.
[0014] It should be noted that in order to adjust the yield of heavy medium separation of raw ore of each particle size, the specific gravity of the heavy medium liquid can be adjusted first. When adjusting the specific gravity of the heavy medium liquid cannot accurately control the product yield, the purpose of controlling the feed pressure and adjusting the product yield can be achieved by adjusting the motor speed.
[0015] In the preferred solution, the weak magnetic separation condition is: magnetic field strength 80-120 kA / m. Weak magnetic separation is performed on the heavy medium to obtain a relatively pure heavy medium. In order to completely recover the heavy medium, the mineral processing product can be subjected to weak magnetic sweeping, and the recovered heavy medium is returned to the process for repeated use.
[0016] In a preferred embodiment, the crusher for crushing the volcanic rock type uranium ore is selected from at least one of a jaw crusher, a high pressure roller mill and a cone crusher.
[0017] The present invention provides, by way of example, a process flow chart for the beneficiation and tailings discarding of volcanic uranium ore according to Example 1 of the present invention.Figure 1 .
[0018] Compared with the prior art, the present invention has at least the following advantages: (1) The present invention crushes the ore to a certain particle size and then classifies it into different particle size grades. Ores of different particle sizes are treated with corresponding heavy medium densities and feed pressures to obtain tailings of a grade that can be discarded, thereby reducing the amount of subsequent grinding and hydrometallurgical processing and significantly reducing the cost of uranium extraction.
[0019] (2) The ore dressing process provided by the present invention has high separation accuracy, can obtain high-grade uranium ore, and has a high recovery rate of uranium ore.
[0020] (3) The mineral processing technology provided by the present invention is purely physical separation, free of chemical pollution, and simple in production and operation. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a process flow chart of volcanic uranium ore beneficiation and tailings discarding in Example 1. DETAILED DESCRIPTION
[0022] The endpoints and any values of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.
[0023] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by professionals in this field without creative work still belong to the protection scope of the present invention.
[0024] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.
[0025] Example 1
[0026] The volcanic uranium ore comes from the Zoujiashan uranium mine in Le'an County, Jiangxi Province.
[0027] (1) The volcanic uranium ore is crushed by a jaw crusher and sieved to obtain ores with particle sizes of -20 mm to +0.56 mm and -0.56 mm. Among them, the -0.56 mm ore contains more fine mud and is not suitable for heavy medium separation. It can be used as a concentrate and directly enter the uranium leaching process.
[0028] (2) First heavy liquid separation: Sodium polytungstate was used to prepare heavy liquids of different densities to separate the volcanic uranium ore with a diameter of -20 mm to +0.56 mm, and ore products of different density levels were obtained. These products were ground and chemically analyzed for uranium grade. The specific gravity and yield of the ore were obtained. The results are shown in Table 1.
[0029] The density of sodium polytungstate heavy liquid is: 3g / cm 3 , 2.95g / cm 3 , 2.9g / cm 3 , 2.85g / cm 3 , 2.8g / cm 3 , 2.75g / cm 3 , 2.72g / cm 3 , 2.7g / cm 3 , 2.65g / cm 3 , 2.6g / cm 3 , 2.55g / cm 3 , 2.5g / cm 3 .
[0030]
[0031] It can be seen from the table that as the specific gravity of the ore increases, the uranium grade in the ore increases, and the minimum density A=2.6 for uranium grade ≥0.02 is determined.
[0032] (3) Ore classification: The ore particles of -20 mm to +0.56 mm obtained in step (1) are classified to obtain ores of -20 mm to +8 mm, -8 mm to +3.2 mm, -3.2 mm to +1.25 mm, and -1.25 mm to +0.56 mm, respectively.
[0033] (4) Second heavy liquid separation: The second heavy liquid was used to separate ores with particle sizes of -20 mm to +8 mm, -8 mm to +3.2 mm, -3.2 mm to +1.25 mm, and -1.25 mm to +0.56 mm, respectively, to obtain ore products of different particle sizes and grades. The uranium grade and yield of the ore products of different particle sizes and grades were analyzed respectively. The specific results are shown in Table 2.
[0034] The density of the second heavy liquid I is 2.5 g / cm 3 , the density of the second heavy liquid II is 2.61 g / cm 3 , the density of the second heavy liquid III is 2.67 g / cm 3 .
[0035]
[0036] From the data in Table 2, it can be calculated that for ores with a particle size of -20mm~+8 mm, the product yield of uranium grade ≥0.022 is 23.77%, and the operating yield is 54.65%; for ores with a particle size of -8mm~+3.2 mm, the product yield of uranium grade ≥0.022 is 7.56%, and the operating yield is 54.66%; for ores with a particle size of -3.2mm~+1.25 mm, the product yield of uranium grade ≥0.022 is 9.03%, and the operating yield is 54.66%; for ores with a particle size of -1.25mm~+0.56 mm, the product yield of uranium grade ≥0.022 is 4.46%, and the operating yield is 63.62%.
[0037] (5) Preparation of heavy medium liquid: the solute is ferrosilicon powder with an iron content of more than 80% and a particle size of less than -0.035 mm.
[0038] (6) Heavy medium separation: Heavy medium cyclone separation is carried out in FZJ250 heavy medium cyclone.
[0039] For ores with a particle size of -20 mm to +8 mm, different concentrate operating rates are set for heavy medium separation: Ore with a particle size of -20mm~+8mm: feed pressure is 0.15 MPa, and the specific gravity of the heavy medium liquid is 2.03g / cm 3 The concentrate operating yield was 60%, the concentrate uranium grade was 0.171%, and the uranium operating recovery rate was 91.95%; the tailings grade was 0.022%, and the tailings uranium operating loss rate was 8.05%.
[0040] Ore with a particle size of -20mm~+8mm: feed pressure is 0.15 MPa, and the specific gravity of the heavy medium liquid is 2.05g / cm 3 The concentrate operating yield was 46%, the concentrate uranium grade was 0.214%, and the uranium operating recovery rate was 88.02%; the tailings grade was 0.025%, and the tailings uranium operating loss rate was 11.98%.
[0041] Ore with a particle size of -20mm~+8mm: feed pressure is 0.14 MPa, and the specific gravity of the heavy medium liquid is 1.95g / cm 3 The concentrate operating yield was 70.96%, the concentrate uranium grade was 0.150%, the uranium operating recovery rate was 95.24%, the tailings grade was 0.018%, and the tailings uranium operating loss rate was 4.76%.
[0042] Heavy medium separation of ores with a particle size of -8mm~+3.2mm: Ore with a particle size of -8mm~+3.2mm: feed pressure is 0.15 MPa, and the specific gravity of the heavy medium liquid is 2.00g / cm 3When the concentrate operating yield was 55.90%, the concentrate uranium grade was 0.346%, the uranium operating recovery rate was 92.61%; the tailings grade was 0.035%, and the tailings uranium operating loss rate was 7.39%.
[0043] Heavy medium separation of ores with a particle size of -3.2 mm to +1.25 mm: Ore with a particle size of -3.2mm~+1.25mm: feed pressure is 0.13 MPa, and the specific gravity of the heavy medium liquid is 2.00g / cm 3 The concentrate operating yield was 49.65%, the concentrate uranium grade was 0.438%, the uranium operating recovery rate was 81.66%, the tailings grade was 0.097%, and the tailings uranium operating loss rate was 18.34%.
[0044] Heavy medium separation of ores with a particle size of -1.25 mm to +0.56 mm: Ore with a particle size of -1.25mm~+0.56mm: feed pressure is 0.13 MPa, and the specific gravity of the heavy medium liquid is 1.85g / cm 3 The concentrate operating yield was 63.91, the concentrate uranium grade was 0.414%, the uranium operating recovery rate was 82.09%; the tailings grade was 0.175%, and the tailings uranium operating loss rate was 17.91%.
[0045] (5) Heavy medium recovery: The concentrate and tailings selected by the heavy medium cyclone are subjected to weak magnetic separation respectively. The heavy medium is weakly magnetically separated under the condition of magnetic field strength of 90kA / m to recover the strong magnetic heavy medium, and the recovered heavy medium is reused.
[0046] It can be seen from the above results that heavy medium beneficiation should be carried out at the same or similar particle size as much as possible to avoid the influence of particle size, and the method provided by the present invention can discard a large amount of tailings under coarse particle conditions and improve the ore grade.
[0047] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.
Claims
1. A volcanic uranium ore dressing and tailings discarding process, characterized in that: The following steps are involved: (1) Desludging: The volcanic uranium ore is crushed and then desludged to obtain ore particles with a particle size of -20 mm to +0.56 mm and ore mud with a particle size of -0.56 mm; (2) First heavy liquid separation: density step is 0.01~0.07g / cm 3 The first batch of heavy liquids with different density gradients are used to perform heavy liquid separation on ore particles with a particle size range of -20 mm to +0.56 mm to obtain ore products with different density levels, and the uranium grades of the ore products with different density levels are analyzed respectively to determine the lowest density A with a uranium grade ≥ 0.02; The minimum density of the first batch of heavy liquid is 2.4-2.55 g / cm 3 ; (3) Ore classification: the ore particles with a size of -20 mm to +0.56 mm obtained in step (1) are screened into at least three material grades to obtain ores of different particle size grades; (4) Second heavy liquid separation: Prepare a second batch of heavy liquids with three different density gradients. In the second batch of heavy liquids, the density of the second heavy liquid I is ≤ (A-0.05) g / cm 3 , the density of the second heavy liquid II is (A±0.03) g / cm 3 , the density of the second heavy liquid III ≥ (A + 0.05) g / cm 3 ; The second batch of heavy liquid is used to perform heavy liquid separation on the ores of different particle sizes to obtain ore products of different particle sizes and density levels, and the uranium grade and yield of the ore products of different particle sizes and density levels are analyzed respectively to determine the product yield B of the ores of each particle size level with a uranium grade ≥ 0.022; (5) Heavy medium separation: ores of different particle sizes are subjected to heavy medium cyclone separation, and the parameters of the heavy medium cyclone separation are controlled so that the concentrate yield of heavy medium separation of ores of each particle size grade is (B±20)%; (6) Magnetic separation: The concentrates and tailings of each particle size obtained by heavy medium cyclone separation are subjected to weak magnetic separation, and the heavy medium is recovered to obtain the final concentrate and final tailings respectively.
2. A volcanic rock type uranium ore dressing tailings discarding process according to claim 1, characterized in that: The density of the second heavy liquid I is (A-0.1~A-0.05) g / cm 3 , the density of the second heavy liquid II is (A±0.03) g / cm 3 , the density of the second heavy liquid III is (A+0.05~A+0.1) g / cm 3 .
3. A volcanic rock type uranium ore dressing and tailings discarding process according to claim 1 or 2, characterized in that: The first heavy liquid and the second heavy liquid are both sodium polytungstate heavy liquids.
4. A volcanic rock type uranium ore dressing and tailings discarding process according to claim 1 or 2, characterized in that: The heavy medium used in the heavy medium cyclone separation is ferrosilicon powder with a particle size of less than 0.05 mm and an iron content of more than 80%.
5. A volcanic rock type uranium ore dressing and tailings discarding process according to claim 4, characterized in that: The specific gravity of the heavy medium liquid used in the heavy medium cyclone separation is 1.5-3.5 g / cm 3 .
6. A volcanic uranium ore dressing and tailings discarding process according to claim 1 or 2, characterized in that: The parameters of the heavy medium cyclone separation include: specific gravity of the heavy medium liquid and feed pressure.
7. A volcanic uranium ore dressing and tailings discarding process according to claim 1 or 2, characterized in that: The conditions for the weak magnetic separation are: magnetic field strength 80-120 kA / m.
8. A volcanic rock type uranium ore dressing and tailings discarding process according to claim 1 or 2, characterized in that: The crusher for crushing the volcanic rock type uranium ore is at least one selected from a jaw crusher, a high pressure roller mill and a cone crusher.
9. A volcanic rock type uranium ore dressing and tailings discarding process according to claim 1 or 2, characterized in that: The method further comprises, in the ore classification step, screening the ore particles of -20 mm to +0.56 mm obtained in step (1) into four material grades, to obtain ores of -20 mm to +8 mm, -8 mm to +3.2 mm, -3.2 mm to +1.25 mm, and -1.25 mm to +0.56 mm, respectively.