A comprehensive extraction method for complex uranium-molybdenum ore

Abstract

The invention discloses a comprehensive extraction method for complex uranium-molybdenum ore. The method comprises the following steps: crushing the complex uranium-molybdenum ore, mixing the ore with an oxidant, an activator and water, and subjecting the ore to ball milling. The ball milled material is slurried and then heated and stirred for leaching. The leached slurry is flocculated and precipitated to obtain a uranium-molybdenum leaching solution. Uranium and molybdenum are separated from the uranium-molybdenum leaching solution through extraction. The method can improve the comprehensive recovery rate of uranium and molybdenum. The entire process is operated at normal pressure and low temperature, is environmentally friendly, is easy to operate, and is conducive to industrial promotion.

Description

Technical Field

[0001] The invention relates to a comprehensive extraction method for complex uranium-molybdenum ore, in particular to a low-grade molybdenum sulfide mineral and its associated ore, especially to a method for extracting and separating uranium and molybdenum from low-grade complex uranium-molybdenum ore, belonging to the technical field of hydrometallurgy. Background Art

[0002] Molybdenum is an important strategic reserve resource and rare metal with good electrical conductivity, thermal conductivity and corrosion resistance. It is widely used in metallurgy, aerospace, machinery manufacturing and chemical industry. With the progress of my country's industrial modernization, the domestic demand for molybdenum has increased, and the reserves of high-quality molybdenum ore have become less and less. The development and utilization of low-grade complex molybdenum ore resources has become a very urgent issue.

[0003] A type of complex associated uranium-molybdenum ore is widely distributed in northern my country, which has great potential utilization value. This type of ore has complex minerality, high oxidation degree, high ore mud content, extremely fine particle size of target minerals, difficult monomer dissociation, and is mostly colloidal minerals. The overall floatability of the mineral is poor, it is difficult to enrich it through mineral processing methods, and it is difficult to process. For the treatment of this type of ore, at present, the domestic main methods are high-pressure oxidation leaching, roasting pretreatment, sulfuric acid roasting, enhanced heap leaching, etc. Although these methods can obtain a higher mineral recovery rate, there are still some problems. High-pressure oxidation leaching equipment is complex, expensive, and difficult to operate and maintain; roasting pretreatment not only has high energy consumption, but also produces a large amount of tail gas, leading to environmental problems, which hinders the promotion of this technology; sulfuric acid roasting consumes a lot of acid, increases the cost of reagents, and has a certain mineral adaptability; because the mineral is easy to muddy, the mineral permeability is poor, and it is easy to cause blockage during heap leaching, and the use of enhanced heap leaching technology is not utilized.

[0004] Therefore, for this type of low-grade complex uranium-molybdenum ore, it is very necessary to improve the recovery rate of molybdenum and uranium and improve the pertinence of the process without increasing a lot of costs. Developing a new process with simple operation and low cost to treat this type of minerals and improve the comprehensive recovery rate of molybdenum and its associated metals is of great significance to the development of my country's molybdenum industry. Summary of the invention

[0005] In view of the defects of the processing methods of complex uranium-molybdenum ores in the prior art, the purpose of the present invention is to provide a comprehensive extraction method for complex uranium-molybdenum ores, especially for such low-grade encapsulated complex uranium-molybdenum ores, which can improve the comprehensive recovery rate of uranium and molybdenum, and the entire process is operated at normal pressure and low temperature, which is environmentally friendly, easy to operate, and conducive to industrial promotion.

[0006] In order to achieve the above technical purpose, the present invention provides a comprehensive extraction method for complex uranium-molybdenum ore, which comprises crushing the complex uranium-molybdenum ore, mixing it with an oxidant, an activator and water, and ball-milling the ball-milled material. The ball-milled material is slurried and then heated and stirred for leaching. The leached slurry is flocculated and precipitated to obtain a uranium-molybdenum leaching solution. The uranium-molybdenum leaching solution is extracted to separate uranium and molybdenum.

[0007] The complex uranium-molybdenum ores targeted by the present invention mainly refer to some uranium-molybdenum ores with complex mineral properties, extremely fine distribution of target minerals, severe encapsulation, sulfide ores in amorphous or crystalline states, and difficult to directly float, enrich or directly leach. Generally speaking, the molybdenum grade is greater than 0.1%, and the uranium grade is greater than 0.01%.

[0008] The technical solution of the present invention is to strengthen the chemical oxidation activation of the complex uranium-molybdenum ore by mechanical ball milling, so that the efficient leaching of uranium and molybdenum in the complex uranium-molybdenum ore can be achieved at low temperature and normal pressure, and then the conventional extraction and separation method is used to achieve the simultaneous recovery of uranium and molybdenum. The complex uranium-molybdenum ore is mixed with an oxidant, an activator and water for ball milling. The effect of ball milling, on the one hand, can reduce the particle size of the complex uranium-molybdenum ore and increase the specific surface area, thereby increasing its contact area with the chemical oxidant and the leaching agent, which is beneficial to the leaching process. On the other hand, the mechanical energy of ball milling is used to activate the mineral, destroy its lattice, reduce the chemical reaction energy barrier, and strengthen the chemical leaching process of the complex uranium-molybdenum ore. The activator mainly provides proton acid or hydroxide, which can not only provide the best acid-base environment for the activation process, which is beneficial to improve the activation efficiency, but also can activate the complex uranium-molybdenum ore, so that the leaching rate of uranium and molybdenum therein is greatly improved.

[0009] As a preferred solution, the complex uranium-molybdenum ore is crushed to a particle size of less than 5 mm. The crusher used in the crushing process can be a roller crusher, a jaw crusher, an impact crusher, an impact crusher, a hammer crusher or a cone crusher. Crushing the complex uranium-molybdenum ore to an appropriate particle size can improve the efficiency of subsequent wet ball milling. In a more preferred solution, the complex uranium-molybdenum ore is crushed to a particle size of less than 4 mm, and in a further preferred solution, the complex uranium-molybdenum ore is crushed to a particle size of less than 2 mm.

[0010] As a preferred solution, the oxidant includes at least one of potassium permanganate, potassium dichromate, sodium perchlorate, sodium chlorate, sodium hypochlorite, manganese dioxide, hydrogen peroxide, nitric acid, and sodium persulfate. These oxidants are conventional chemical oxidants, and the best oxidant can be specifically selected according to the type of complex uranium-molybdenum ore.

[0011] As a preferred embodiment, the activator includes at least one of sodium carbonate, sodium bicarbonate, ammonium carbonate, sodium bisulfate, sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, sulfuric acid, hydrochloric acid, nitric acid, sulfurous acid, hydrogen sulfide, sodium sulfite, sodium sulfide, sodium hydrosulfide, and ammonium bisulfate.

[0012] As a preferred solution, the amount of the oxidant is 0.01% to 5% of the mass of the complex uranium-molybdenum ore. If the amount of the oxidant is too high, the cost will increase, while if the amount of the oxidant is too low, the effect will not be achieved.

[0013] As a preferred solution, the dosage of the activator is 0.01% to 3% of the mass of the complex uranium-molybdenum ore.

[0014] As a preferred solution, the amount of water used is 0.4 to 4 times the mass of the complex uranium-molybdenum ore.

[0015] As a preferred solution, the ball milling conditions are as follows: the rotation speed of the ball mill is 50 to 500 rpm, the ball-to-material ratio is (1 to 20):1, and the ball milling time is 1 min to 12 h.

[0016] As a preferred solution, the slurry is adjusted to adjust the liquid-solid ratio to 0.4:1-4:1, and an acid solution or an alkali solution is added as a leaching agent. As a more preferred solution, the acid solution contains at least one of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, and sulfurous acid, and the mass percentage concentration of the acid solution is 0.5-20%. As a more preferred solution, the alkali solution contains at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, and calcium oxide, and the mass percentage concentration of the alkali solution is 0.1-15%. The more preferred acid is an inorganic acid, which can reduce costs. The cost of selecting acid leaching is lower, while the leaching selectivity of selecting alkali leaching is relatively improved, but the leaching effect is slightly worse and the cost is slightly higher, so it can be selected according to actual conditions.

[0017] As a preferred solution, the conditions for the heated stirring leaching are: a temperature of 20 to 100°C, a stirring rate of 10 to 1000 rpm, and a stirring time of 30 min to 48 h. Properly increasing the leaching temperature is conducive to accelerating the leaching rate, but when the leaching temperature reaches 100°C, water volatilization is serious. Therefore, the preferred temperature is 40 to 90°C, and the further preferred temperature is 60 to 90°C. The leaching time is correspondingly shortened as the leaching temperature increases. The mass transfer efficiency can be improved at an appropriate stirring rate, thereby accelerating the leaching process.

[0018] As a preferred solution, the flocculation precipitation uses at least one flocculant selected from polyaluminium chloride, aluminium sulfate, polyaluminium chloride iron, ferrous sulfate, ferric chloride, starch, cellulose, chitosan and acrylamide, and the amount of the flocculant added is 1 to 100 g / t relative to the complex uranium-molybdenum ore. During the flocculation and precipitation process, solid-liquid separation is performed by suction filtration, filter pressing, centrifugation, sedimentation and the like, but is not limited thereto, and the separation method is for the purpose of convenience and low cost.

[0019] As a preferred solution, the extraction separation uses phosphate esters as an extractant. Preferred phosphonates include at least one of diisooctyl phosphate, 2-ethylhexyl phosphate, and tributyl phosphate. The extraction organic phase used in the extraction separation contains a phosphate ester extractant, a trioctylamine modifier, and kerosene. The preferred extractant can achieve efficient extraction of molybdenum and uranium at the same time.

[0020] As a preferred solution, the raffinate produced during the extraction process is returned to the ball milling process or the heated stirring leaching process.

[0021] Compared with the existing technical solutions, the technical solution of the present invention has the following technical advantages:

[0022] 1) The technical solution of the present invention adopts mechanical ball milling to strengthen the chemical oxidation activation of complex uranium-molybdenum ore, so as to achieve efficient leaching of uranium and molybdenum in the complex uranium-molybdenum ore at low temperature and normal pressure, effectively improve the recovery rate of molybdenum and uranium, and realize the comprehensive recycling of minerals.

[0023] 2) The technical solution of the present invention is a full wet process, and the process does not produce SO 2 And other harmful gases, the process is environmentally friendly.

[0024] 3) The technical solution of the present invention does not require special equipment and is operated at normal pressure, has a simple process flow, and is suitable for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a process flow chart of the comprehensive extraction technology of complex uranium-molybdenum ores of the present invention. DETAILED DESCRIPTION

[0026] The following content is a specific implementation mode of the present invention, and the technical solution of the present invention is further explained in conjunction with the accompanying drawings. The following embodiments are simple application examples of the present invention and cannot limit the scope of protection of the present invention. The scope of protection of the present invention is still subject to the claims.

[0027] Example 1

[0028] As a comparative experiment: a complex uranium-molybdenum ore containing 0.3% molybdenum and 0.01% uranium grades was crushed to less than 4 mm and added to a ball mill. Water of 1 times the amount of mineral was added to the ball mill. The ball mill speed was 100 rpm, and the ball-to-material mass ratio was 15:1. After 60 minutes of ball milling, the slurry was transferred to a stirring tank. Sulfuric acid solution was added to the slurry at a liquid-solid ratio of 1:1. The mass concentration of the sulfuric acid solution was 10%. It was heated to 90°C, stirred for 12 hours, cooled to 30°C, and a flocculant polyaluminium chloride was added in an amount of 20 g / L. The filtrate was separated by filter press. The pH of the solution was controlled at 4. A mixture of diisooctyl phosphate, trioctylamine and kerosene in a ratio of 1:1 was added to extract molybdenum and uranium. The obtained leaching residue was analyzed. The contents of molybdenum and uranium in the slag were 0.14% and 0.006%, respectively, and the recovery rates of molybdenum and uranium were 53% and 40%, respectively.

[0029] Example 2

[0030] A complex uranium-molybdenum ore containing 0.3% molybdenum and 0.01% uranium grades respectively was crushed to less than 4 mm and added to a ball mill. Potassium permanganate (0.2% of the mineral amount), sodium sulfite (0.05%) and 1 times of water were added to the ball mill at the same time. The ball mill speed was 100 rpm, and the ball-to-material mass ratio was 15:1. After ball milling for 60 minutes, the slurry was transferred to a stirring tank, and sulfuric acid solution was added to the slurry at a liquid-to-solid ratio of 1:1. The mass concentration of the sulfuric acid solution was 10%. The slurry was heated to 90°C, stirred for 12 hours, cooled to 30°C, and a flocculant polyaluminium chloride was added in an amount of 20 g / L. The filtrate was separated by filter pressing, the pH of the solution was controlled at 4, and a mixed solution of diisooctyl phosphate, trioctylamine and kerosene in a ratio of 1:1 was added to extract the molybdenum and uranium. The obtained leaching residue was analyzed, and the contents of molybdenum and uranium in the residue were 0.04% and 0.005% respectively, and the recovery rates of molybdenum and uranium were 86.7% and 50% respectively.

[0031] Example 3

[0032] A complex uranium-molybdenum ore containing 0.24% molybdenum and 0.018% uranium grades respectively was crushed to less than 2 mm and added to a ball mill. 1% of the mineral amount of sodium hypochlorite, 0.5% of sodium carbonate and 50% of water were added to the ball mill at the same time. The ball mill speed was 100 rpm, and the ball-to-material mass ratio was 2:1. After ball milling for 10 hours, the slurry was transferred to a stirring tank, and a hydrochloric acid solution was added to the slurry according to a solid-liquid ratio of 3:1. The mass concentration of the hydrochloric acid solution was 8%. The slurry was heated to 70°C, stirred for 6 hours, cooled to 25°C, and a flocculant ferrous sulfate was added in an amount of 5 g / L. After settling for 10 minutes, the supernatant was separated, the pH of the solution was controlled at 2, and a mixed solution of tributyl phosphate, trioctylamine and kerosene in a ratio of 0.5:2:7.5 was added in a ratio of 1:1 to extract molybdenum and uranium. The obtained leaching residue was analyzed, and the contents of molybdenum and uranium in the residue were 0.05% and 0.006% respectively, and the recovery rates of molybdenum and uranium were 79.2% and 66.6% respectively.

[0033] Example 4

[0034] A complex uranium-molybdenum ore containing 0.62% molybdenum and 0.03% uranium grades respectively was crushed to less than 1 mm and added to a ball mill. 2% of the mineral amount of hydrogen peroxide, 0.1% of sodium sulfide, and 400% of water were added to the ball mill at the same time. The ball mill speed was 400rpm, and the ball-to-material mass ratio was 10:1. After ball milling for 4 hours, the slurry was transferred to a stirring tank, sulfuric acid was added to the slurry according to a liquid-to-solid ratio of 4:1, and the mass concentration of sulfuric acid was 10%. The slurry was heated to 80°C, stirred for 16 hours, cooled to 30°C, and a flocculant cellulose was added in an amount of 10 g / L. The filtrate was filtered by vacuum filtration. The pH of the filtrate was controlled at 5. A mixed solution of 2-ethylhexyl phosphate, trioctylamine and kerosene in a ratio of 2:1:7 was added in a ratio of 2:1 to extract molybdenum and uranium. The obtained leaching residue was analyzed, and the contents of molybdenum and uranium in the residue were 0.05% and 0.006% respectively, and the recovery rates of molybdenum and uranium were 92% and 80% respectively.

[0035] Example 5

[0036] A complex uranium-molybdenum ore containing 0.3% molybdenum and 0.01% uranium grades respectively was crushed to less than 1 mm and added to a ball mill. Potassium permanganate (0.5% of the mineral amount), sodium bicarbonate (0.5%) and water (150%) were added to the ball mill at the same time. The ball mill speed was 100 rpm and the ball-to-material mass ratio was 2:1. After 30 minutes of ball milling, the slurry was transferred to a stirring tank. Sodium hydroxide solution was added to the slurry at a liquid-to-solid ratio of 2:1. The mass concentration of the sodium hydroxide solution was 10%. The slurry was heated to 90°C, stirred for 16 hours, cooled to 30°C, and a flocculant cellulose was added in an amount of 10 g / L. The filtrate was filtered by vacuum filtration. The pH of the filtrate was controlled at 5. A mixed solution of 2-ethylhexyl phosphate, trioctylamine and kerosene in a ratio of 2:1:7 was added in a ratio of 0.8:1 to extract molybdenum and uranium. The obtained leaching residue was analyzed, and the contents of molybdenum and uranium in the residue were 0.045% and 0.007% respectively, and the recovery rates of molybdenum and uranium were 85% and 30% respectively.

Claims

1. A comprehensive extraction method for complex uranium-molybdenum ores, characterized in that: The complex uranium-molybdenum ore is crushed and then mixed with an oxidant, an activator and water for ball milling. The ball milled material is slurried and then heated and stirred for leaching. The leached slurry is flocculated and precipitated to obtain a uranium-molybdenum leaching solution, and the uranium-molybdenum leaching solution is extracted and separated into uranium and molybdenum. The amount of the oxidant is 0.01% to 5% of the mass of the complex uranium-molybdenum ore; the amount of the activator is 0.01% to 3% of the mass of the complex uranium-molybdenum ore; the amount of water is 0.4 to 4 times the mass of the complex uranium-molybdenum ore; the extraction and separation uses a phosphate extractant, the molybdenum grade in the complex uranium-molybdenum ore is greater than 0.1% and less than or equal to 0.62%, and the uranium grade is greater than 0.01% and less than or equal to 0.03%.

2. The comprehensive extraction method of a complex uranium-molybdenum ore according to claim 1, characterized in that: The complex uranium-molybdenum ore is crushed to a particle size below 5 mm.

3. The comprehensive extraction method of complex 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, nitric acid, and sodium persulfate.

4. The comprehensive extraction method of complex uranium-molybdenum ore according to claim 1, characterized in that: The activator includes at least one of sodium carbonate, sodium bicarbonate, ammonium carbonate, sodium bisulfate, sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, sulfuric acid, hydrochloric acid, nitric acid, sulfurous acid, hydrosulfuric acid, sodium sulfite, sodium sulfide, sodium hydrosulfide, and ammonium bisulfate.

5. A comprehensive extraction method for complex uranium-molybdenum ore according to any one of claims 1 to 4, characterized in that: The ball milling conditions are as follows: the ball milling speed is 50-500 rpm, the ball-to-material ratio is (1-20):1, and the ball milling time is 1 min-12 h.

6. A comprehensive extraction method for complex uranium-molybdenum ore according to any one of claims 1 to 4, characterized in that: The slurry is adjusted to adjust the liquid-to-solid ratio to 0.4:1~5:1, and acid or alkali solution is added as a leaching agent. The acid solution contains at least one of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, and sulfurous acid, and the mass percentage concentration of the acid solution is 0.5%~20%; the alkali solution contains at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, and calcium oxide, and the mass percentage concentration of the alkali solution is 0.1%~15%.

7. A comprehensive extraction method for complex uranium-molybdenum ore according to any one of claims 1 to 4, characterized in that: The conditions for the heating and stirring leaching are: a temperature of 70-100° C., a stirring rate of 10-1000 rpm, and a stirring time of 30 min-48 h.

8. A comprehensive extraction method for complex uranium-molybdenum ore according to any one of claims 1 to 4, characterized in that: The flocculation precipitation adopts at least one flocculant selected from polyaluminium chloride, aluminium sulfate, polyaluminium ferric chloride, ferrous sulfate, ferric chloride, starch, cellulose, chitosan and acrylamide, and the addition amount of the flocculant is 1-100g / t relative to the complex uranium-molybdenum ore.

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