A method for selective separation of low-grade uranium-molybdenum ore in the form of a package
By performing two ball milling processes on low-grade encapsulated uranium-molybdenum ore and controlling the pH value under alkaline conditions, the problem of uranium-molybdenum separation in existing technologies has been solved, achieving efficient separation and low-cost recovery of uranium-molybdenum, which has environmental benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING RESEARCH INSTITUTE OF CHEMICAL ENGINEERING AND METALLURGY
- Filing Date
- 2023-08-30
- Publication Date
- 2026-05-15
AI Technical Summary
Existing technologies for processing low-grade encapsulated uranium-molybdenum ores suffer from high equipment costs, operational difficulties, severe environmental pollution, and complex separation processes, making it difficult to achieve efficient and low-cost uranium-molybdenum separation.
By employing two ball milling processes and controlling alkaline conditions with different pH values, the uranium-molybdenum ore raw material is activated through ball milling and the pH value is adjusted, allowing uranium to be leached under acidic conditions and molybdenum to be leached under alkaline conditions, thus achieving selective separation of uranium and molybdenum.
This method achieves efficient separation and recovery of uranium and molybdenum, reduces separation costs, avoids reagent waste and environmental pollution, and is simple and environmentally friendly.
Smart Images
Figure CN117127034B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a mineral separation method, specifically a selective separation method for low-grade encapsulated uranium-molybdenum ore, belonging to the field of hydrometallurgy. Background Technology
[0002] Molybdenum is a rare, refractory metal with excellent physical and chemical properties, including high strength, high melting point, wear resistance, and corrosion resistance. It is widely used in metallurgy, chemical industry, electronics, aerospace, biomedicine, and agriculture, and is an important raw material and irreplaceable strategic resource. Molybdenum metal usually does not exist naturally in its monomeric form but is associated with other elements. Uranium is a common associated element; it is the material basis for the development of the nuclear industry and an important strategic energy mineral. my country possesses a typical low-grade, complex uranium-molybdenum deposit, where the states of uranium and molybdenum are quite complex. Uranium minerals exist as independent minerals, adsorbed states, and inclusions; molybdenum minerals include molybdenite travertine, ferromolybdenite travertine, sulphite, molybdenite-tungsten-calcium ore, and molybdenite-lead ore.
[0003] With the development of my country's national economy, mineral resources have been largely depleted after decades of mining and processing. High-quality uranium and molybdenum ores are now mostly exhausted, leaving behind a growing proportion of difficult-to-mine, difficult-to-process, and frequently associated minerals. Numerous studies have confirmed that these low-grade, encapsulated uranium-molybdenum ores are unsuitable for beneficiation methods. Therefore, current research primarily focuses on directly extracting uranium and molybdenum from ores, mainly through high-pressure leaching, roasting pretreatment, and enhanced heap leaching. While high-pressure leaching is a mature technology with high product recovery rates, it suffers from high equipment costs, high maintenance costs, operational difficulties, and complex subsequent separation and recovery processes. Roasting pretreatment not only has high energy consumption but also emits harmful gases such as SO2, polluting the environment. Enhanced heap leaching, while relatively low-cost, suffers from poor ore permeability due to the mineral's tendency to become muddy, thus affecting leaching efficiency. Therefore, it is necessary to strengthen research on mineral extraction technologies and develop a low-cost, easy-to-operate, and environmentally friendly technology to improve the overall economic benefits of ores. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the present invention aims to provide a selective separation method for low-grade encapsulated uranium-molybdenum ore. This method is simple, has high uranium-molybdenum separation and recovery efficiency, and is low in cost, effectively solving problems such as the difficulty in separating encapsulated uranium-molybdenum ore.
[0005] To achieve the above objectives, the present invention provides a method for the selective separation of low-grade encapsulated uranium-molybdenum ore, comprising the following steps:
[0006] 1) Mix uranium-molybdenum ore raw material with water and ball mill until the particle size of uranium-molybdenum ore is ≤50 mesh to obtain uranium-molybdenum ore slurry. After adjusting the pH of the uranium-molybdenum ore slurry to 7~10, perform solid-liquid separation to obtain uranium-containing leachate and uranium-removed residue.
[0007] 2) The uranium removal slag is mixed with oxidant and water and ball-milled until the particle size of the uranium removal slag is ≤100 mesh to obtain uranium removal slurry;
[0008] 3) The uranium-depleted slurry is subjected to an alkaline leaching reaction, and the pH of the leaching reaction system is controlled to be ≥12. The resulting product is separated into a molybdenum-containing leachate and tailings.
[0009] This invention first activates uranium-molybdenum ore raw materials through ball milling, promoting the extraction and separation of uranium. Then, by adjusting the pH of the ball-milled uranium-molybdenum ore slurry to an alkaline range of 7-10, uranium is fully leached into the solution while molybdenum remains in the slag phase, thus achieving the separation of uranium and molybdenum. Next, the resulting uranium-removed slag is ball-milled and activated to convert molybdenum sulfide into oxidized molybdenum, improving the leaching efficiency of molybdenum. Finally, the uranium-removed slurry obtained after ball milling and activation is subjected to alkaline leaching at pH ≥ 12, which promotes better leaching of molybdenum into the solution, thereby achieving the extraction and separation of molybdenum.
[0010] As a preferred embodiment, the molybdenum content in the uranium-molybdenum ore raw material is ≤2wt%.
[0011] As a preferred option, the uranium-molybdenum ore raw material is crushed to less than 2 mm and then ball-milled.
[0012] As a preferred embodiment, the mass ratio of the uranium-molybdenum ore raw material to water is 1:0.5~4.
[0013] As a preferred embodiment, the ball-to-material ratio during the ball milling process of the uranium-molybdenum ore is 1~3:1, the ball milling time is 10~120 min, and the ball milling speed is 50~400 rpm.
[0014] As a preferred embodiment, in step 1), at least one of sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide, ammonia, ammonium carbonate solution, and ammonium bicarbonate solution is used as a pH adjuster.
[0015] As a preferred embodiment, the uranium-molybdenum ore raw material is mixed with water and additives and ball-milled.
[0016] As a preferred embodiment, the additive includes at least one of potassium permanganate, potassium dichromate, sodium perchlorate, sodium chlorate, sodium hypochlorite, manganese dioxide, hydrogen peroxide, sodium persulfate, ferric sulfate, ferric chloride, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.
[0017] As a preferred embodiment, the amount of the additive is 0.5 to 10 wt% of uranium-molybdenum ore.
[0018] As a preferred embodiment, the oxidant includes at least one of potassium permanganate, potassium dichromate, sodium perchlorate, sodium chlorate, sodium hypochlorite, manganese dioxide, hydrogen peroxide, sodium persulfate, ferric sulfate, and ferric chloride.
[0019] As a preferred embodiment, the amount of oxidant used is 0.5 to 10 wt% of the uranium removal slag.
[0020] As a preferred embodiment, the ball-to-material ratio is controlled to be 1~3:1, the ball-milling time is 10~480 min, and the ball-milling speed is 50~400 rpm during the ball milling process of the uranium-removed slag.
[0021] As a preferred embodiment, the mass ratio of the uranium removal residue to water is 1:0.5~4.
[0022] As a preferred embodiment, during the alkaline leaching reaction, the pH of the leaching reaction system is controlled to be 12-14.
[0023] As a preferred embodiment, at least one of sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide solution, ammonia water, ammonium carbonate solution, and ammonium bicarbonate solution is used as the leaching agent in the alkaline leaching reaction process.
[0024] As a preferred embodiment, the mass concentration of the leaching agent is 1-20%.
[0025] As a preferred embodiment, the alkaline leaching reaction is carried out at a temperature of 30-100°C for a duration of 1-24 hours. More preferably, the alkaline leaching reaction temperature is 85-95°C, and the leaching time is 3-9 hours.
[0026] Compared with existing technologies, the advantages of this invention are:
[0027] (1) By ball milling twice and controlling different alkaline conditions, uranium and molybdenum are gradually separated and recovered, avoiding the waste of reagents and environmental pollution caused by uranium and molybdenum entering the solution at the same time, which greatly reduces the separation cost and is green and environmentally friendly.
[0028] (2) It achieves efficient separation and recovery of uranium and molybdenum. At the same time, the process is simple and controllable, effectively preventing harmful substances such as gas, solid and liquid from harming the environment and improving environmental protection benefits. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the selective separation method for low-grade encapsulated uranium-molybdenum ore according to the present invention. Detailed Implementation
[0030] The following detailed description of the present invention is provided in conjunction with specific embodiments. The embodiments described below are for illustrative purposes only and do not imply that the scope of protection of the claims of the present invention is limited to the embodiments described below. All technologies implemented based on the present invention fall within the scope of protection of the present invention.
[0031] Example 1
[0032] The uranium-molybdenum ore used in this embodiment has a SiO2 content of 73.3%, an Al2O3 content of 14.8%, an Fe2O3 content of 3.2%, a molybdenum content of 0.3%, and a uranium content of 0.013%.
[0033] (1) First, the uranium-molybdenum ore is crushed to below 2 mm using a jaw crusher and roller crusher. The mineral and water are added to a ball mill at a mass ratio of 1:1, and sodium bicarbonate is added at 5% of the mineral weight ratio. The ball-to-material ratio is controlled at 2:1. The ball mill is run for 0.5 hours at a speed of 100 rpm until the mineral particle size is less than 50 mesh. The slurry after ball milling is added to a stirring tank and stirred at 30°C for 8 hours. The pH of the slurry is controlled to be 9 using sodium hydroxide solution. After the reaction is complete, the uranium-containing leachate and uranium-removed slag are obtained by vacuum filtration.
[0034] (2) The leachate is used to extract uranium. The filtered uranium-depleted residue and water are added to the ball mill at a solid-liquid mass ratio of 1:2. 2% NaClO is added according to the weight ratio of the uranium-depleted residue. The ball-to-material ratio is controlled at 2:1. The ball mill is milled for 30 minutes at a speed of 100 rpm until the mineral particle size is less than 100 mesh to obtain the uranium-depleted slurry.
[0035] (3) The uranium-removed slurry after ball milling was transferred to a stirred tank, and NaOH solution was added as a leaching agent. The mass concentration of the NaOH aqueous solution was controlled at 10%, and the mixture was stirred at 80°C for 10 hours, with the pH of the system controlled at 13. Vacuum filtration was used to obtain molybdenum-containing leachate and tailings. After leaching, the tailings were tested, and the molybdenum content in the tailings was 0.07%, and the uranium content was 0.0056%; the leaching rates of molybdenum and uranium were 76.6% and 56.9%, respectively.
[0036] Example 2
[0037] The uranium-molybdenum ore used in this embodiment has a SiO2 content of 65%, an Al2O3 content of 11.2%, an Fe2O3 content of 1.2%, a molybdenum content of 0.24%, and a uranium content of 0.018%.
[0038] (1) First, the uranium-molybdenum ore is crushed to below 2 mm using a jaw crusher and roller crusher. The mineral and water are added to a ball mill at a mass ratio of 1:1. Sodium bicarbonate and 0.5% MnO2 are added at 5% of the mineral weight ratio, and the ball-to-material ratio is controlled at 3:1. The ball mill is run for 1 hour at a speed of 200 rpm until the mineral particle size is less than 100 mesh. The slurry after ball milling is transferred to a stirring tank and stirred at 80°C for 4 hours. The pH is controlled to be 8 using ammonia water. Vacuum filtration is then performed to separate the uranium-containing leachate and uranium-removed slag.
[0039] (2) The leachate is used to extract uranium. The filtered uranium-depleted residue and water are added to the ball mill at a solid-liquid mass ratio of 1:1.5. 1% MnO2 is added according to the weight ratio of the uranium-depleted residue. The ball-to-material ratio is controlled at 1:1 and the ball milling is carried out for 30 minutes at a speed of 200 rpm. The ball milling is carried out until the mineral particle size is less than 200 mesh to obtain the uranium-depleted slurry.
[0040] (3) The uranium-removed slurry after ball milling was transferred to a stirred tank, and NH3·H2O was added as a leaching agent. The mass concentration of ammonia water was 15%. The mixture was stirred at 60°C for 6 hours, and the pH after the reaction was 12.5. Vacuum filtration was used to obtain molybdenum-containing leachate and tailings. After leaching, the tailings were tested, and the molybdenum content in the tailings was 0.05%, and the uranium content was 0.0063%. The leaching rates of molybdenum and uranium were 79.2% and 65%, respectively.
[0041] Example 3
[0042] The uranium-molybdenum ore used in this embodiment has a SiO2 content of 59.1%, an Al2O3 content of 6.4%, an Fe2O3 content of 3.4%, a molybdenum content of 0.78%, and a uranium content of 0.021%.
[0043] (1) First, the uranium-molybdenum ore is crushed to below 2 mm using a jaw crusher and roller crusher. The mineral and water are added to a ball mill at a mass ratio of 1:1. Sodium carbonate, sodium bicarbonate, and H2O2 are added at 3% of the mineral weight, and the ball-to-material ratio is controlled at 1:1. The ball mill is run for 0.5 hours at a speed of 300 rpm until the mineral particle size is less than 60 mesh. The slurry after ball milling is transferred to a stirring tank and stirred at 50°C for 9 hours. The pH is controlled at 7.5 using sodium hydroxide solution. Vacuum filtration is then performed to separate the uranium-containing leachate and uranium-removed slag.
[0044] (2) The leachate is used to extract uranium. The filtered uranium-depleted residue and water are added to the ball mill at a solid-liquid mass ratio of 1:3. 1.5% potassium chlorate is added according to the weight ratio of the uranium-depleted residue. The ball-to-material ratio is controlled at 1.5:1. The ball mill is run for 0.5 hours at a speed of 200 rpm until the mineral particle size is less than 300 mesh to obtain the uranium-depleted slurry.
[0045] (3) The uranium-removed slurry after ball milling was transferred to a stirred tank, and a mixed solution of NaOH and ammonium carbonate was added as a leaching agent, wherein the mass concentration of NaOH was 10% and the mass concentration of ammonium carbonate was 5%. The mixture was stirred at 90°C for 9 hours, and the pH after the reaction was 12.8. The molybdenum-containing leaching solution and tailings were obtained by vacuum filtration. After leaching, the tailings were tested, and the molybdenum content in the tailings was 0.085%, and the uranium content was 0.0072%; the leaching rates of molybdenum and uranium were 89.1% and 65.7%, respectively.
[0046] Comparative Example 1
[0047] The method of Example 1 was used to selectively separate low-grade encapsulated uranium-molybdenum ore, except that in step (1), the pH of the slurry was controlled to be 11.
[0048] After leaching, the tailings were tested and found to contain 0.06% molybdenum and 0.015% uranium; the leaching rates of molybdenum and uranium were 75% and 20%, respectively.
[0049] Comparative Example 2
[0050] The method of Example 1 was used to selectively separate low-grade encapsulated uranium-molybdenum ore, except that in step (3), the pH of the alkaline leaching system was controlled to be 9.
[0051] After leaching, the tailings were tested and found to contain 0.1% molybdenum and 0.006% uranium; the leaching rates of molybdenum and uranium were 58.3% and 66.7%, respectively.
[0052] Comparative Example 3
[0053] The method of Example 1 was used to selectively separate low-grade encapsulated uranium-molybdenum ore, except that NaClO was not added during the ball milling of the uranium removal slag in step (2).
[0054] After leaching, the tailings were tested and found to contain 0.12% molybdenum and 0.0065% uranium. The leaching rates for molybdenum and uranium were 50% and 63.8%, respectively.
Claims
1. A method for selective separation of low-grade encapsulated uranium-molybdenum ore, characterized in that: Includes the following steps: 1) Mix uranium-molybdenum ore raw materials with water and additives and ball mill them until the particle size of uranium-molybdenum ore is ≤50 mesh to obtain uranium-molybdenum ore slurry. After adjusting the pH of the uranium-molybdenum ore slurry to 7~10, solid-liquid separation is performed to obtain uranium-containing leachate and uranium-removed residue. 2) The uranium removal slag is mixed with oxidant and water and ball-milled until the particle size of the uranium removal slag is ≤100 mesh to obtain uranium removal slurry; 3) The uranium-depleted slurry is subjected to an alkaline leaching reaction, and the pH of the leaching reaction system is controlled to be ≥12. The resulting product is separated into a molybdenum-containing leaching solution and tailings. The molybdenum content in the uranium-molybdenum ore raw material is ≤2wt%; The additive is at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. The amount of the additive is 0.5 to 10 wt% of the uranium-molybdenum ore raw material.
2. The selective separation method for low-grade encapsulated uranium-molybdenum ore according to claim 1, characterized in that: The mass ratio of the uranium-molybdenum ore raw material to water is 1:0.5~4.
3. The selective separation method for low-grade encapsulated uranium-molybdenum ore according to claim 1, characterized in that: The oxidant includes at least one of potassium permanganate, potassium dichromate, sodium perchlorate, sodium chlorate, sodium hypochlorite, manganese dioxide, hydrogen peroxide, sodium persulfate, ferric sulfate, and ferric chloride.
4. A selective separation method for low-grade encapsulated uranium-molybdenum ore according to claim 1 or 3, characterized in that: The amount of oxidant used is 0.5~10 wt% of the uranium removal residue.
5. A selective separation method for low-grade encapsulated uranium-molybdenum ore according to claim 1 or 3, characterized in that: The mass ratio of the uranium removal residue to water is 1:0.5~4.
6. The selective separation method for low-grade encapsulated uranium-molybdenum ore according to claim 1, characterized in that: In the alkaline leaching reaction, at least one of the following is used as the leaching agent: sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide solution, ammonia water, ammonium carbonate solution, and ammonium bicarbonate solution.
7. The selective separation method for low-grade encapsulated uranium-molybdenum ore according to claim 6, characterized in that: The mass concentration of the leaching agent is 1-20%.
8. A method for selective separation of low-grade encapsulated uranium-molybdenum ore according to claim 1, 6, or 7, characterized in that: During the alkaline leaching reaction, the temperature is controlled at 30~100℃ and the time is 1~24h.