Method for activating and decomposing tantalum-niobium concentrate

Abstract

This application provides a method for the activation, transformation, and decomposition of niobium-tantalum concentrate, relating to the field of niobium-tantalum concentrate decomposition. The method includes: first mixing niobium-tantalum concentrate, pyrosulfate, and a first sulfuric acid to obtain a mixture; activating and roasting the mixture to obtain activated roasted sand; washing the activated roasted sand with water to obtain a water-washed solution and niobium-tantalum slag; and acid leaching the niobium-tantalum slag in a mixed acid to obtain a niobium-tantalum solution; the mixed acid includes hydrofluoric acid and a second sulfuric acid. This method for the activation, transformation, and decomposition of niobium-tantalum concentrate achieves efficient decomposition of difficult-to-decompose niobium-tantalum concentrate, while reducing acid mist pollution and equipment corrosion generated during the decomposition of high-concentration hydrofluoric acid, and improving the effective utilization rate of hydrofluoric acid.

Description

Technical Field

[0001] This application relates to the field of niobium-tantalum concentrate decomposition, and more particularly to a method for the activation, transformation, and decomposition of niobium-tantalum concentrate. Background Technology

[0002] Niobium and tantalum are strategically critical metal resources, considered the cornerstone of miniaturization and high reliability in the electronics industry. They are widely used in electronics, aerospace, and superconducting materials, and are irreplaceable in certain key areas. my country's niobium and tantalum resources are poor, their beneficiation and smelting are difficult, and its dependence on imports is high, posing a significant challenge to resource security. Therefore, developing efficient, economical, green, and safe processing technologies for rutile and other difficult-to-process niobium and tantalum concentrates in my country has become a recognized major technical challenge within the industry.

[0003] Currently, the main methods for recovering and processing niobium and tantalum resources include alkaline decomposition, hydrofluoric acid-sulfuric acid decomposition, and chlorination. Among these, the hydrofluoric acid-sulfuric acid decomposition method has become the mainstream method for industrial processing of niobium and tantalum concentrate due to its relatively simple process and wide applicability. However, this method faces significant technical bottlenecks when applied to rutile niobium and tantalum concentrate: rutile niobium and tantalum concentrate has a dense crystal structure and high bond energy, resulting in a low decomposition rate under conventional mixed acid systems, making it difficult to achieve efficient recovery of niobium and tantalum; to overcome the decomposition efficiency limitation, high-concentration hydrofluoric acid is required, which not only leads to insufficient effective utilization of hydrofluoric acid but also generates a large amount of acid mist, severely corroding equipment and polluting the operating environment; at the same time, the use of high-concentration hydrofluoric acid also increases production costs and the difficulty of safety management.

[0004] While alkaline decomposition is slightly more environmentally friendly, it suffers from harsh reaction conditions, high energy consumption, and complex subsequent separation processes, making it unsuitable for large-scale industrial production. Chlorination, on the other hand, has extremely high requirements for equipment materials, poses significant safety risks during the reaction process, and is only applicable to high-grade niobium-tantalum concentrates, limiting its applicability to a narrow range of raw materials.

[0005] In summary, existing decomposition methods for rutile-type refractory niobium-tantalum concentrate all have significant shortcomings: the hydrofluoric acid-sulfuric acid decomposition method has low decomposition efficiency, high hydrofluoric acid consumption, and severe corrosion and pollution; the alkaline decomposition method has harsh conditions, high energy consumption, and a complex process; and the chlorination method has high equipment requirements, significant safety risks, and poor raw material adaptability. Therefore, there is an urgent need to develop a new processing technology that is highly efficient, consumes low reagents, is environmentally friendly, and suitable for rutile-type niobium-tantalum concentrate, in order to achieve efficient, economical, and green recovery of niobium-tantalum resources. Summary of the Invention

[0006] The purpose of this application is to provide a method for the activation, transformation, and decomposition of niobium-tantalum concentrate to solve the above-mentioned problems.

[0007] To achieve the above objectives, this application provides a method for the activation, transformation, and decomposition of niobium-tantalum concentrate, comprising: Niobium-tantalum concentrate, pyrosulfate, and first sulfuric acid are first mixed to obtain a mixture; The mixture is activated and calcined to obtain activated calcined sand; The activated calcined sand was washed with water to obtain a water washing solution and niobium-tantalum slag. The niobium-tantalum slag is leached in a mixed acid to obtain a niobium-tantalum solution; The mixed acid includes hydrofluoric acid and second sulfuric acid.

[0008] Optionally, the niobium-tantalum concentrate includes at least one of columbite-iron rutile, tantalite-iron rutile, columbite-tantalite, and tin-tantalite-iron rutile.

[0009] Optionally, the proportion of the niobium-tantalum concentrate with a particle size of less than 0.074 mm is ≥80%.

[0010] Optionally, the mass ratio of the niobium-tantalum concentrate, the pyrosulfate, and the first sulfuric acid is 1:0.1-0.5:0.2-0.5.

[0011] Optionally, the pyrosulfate includes at least one of potassium pyrosulfate, sodium pyrosulfate, and ammonium pyrosulfate; And / or, the mass concentration of the first sulfuric acid is 90-98%.

[0012] Optionally, the activation calcination temperature is 350-600℃ and the time is 10-150 min.

[0013] Optionally, the mass ratio of the hydrofluoric acid to the niobium-tantalum concentrate is 0.5-0.8:1; And / or, the mass ratio of the second sulfuric acid to the niobium-tantalum concentrate is 0.6-1.2:1.

[0014] Optionally, the concentration of the hydrofluoric acid is 16-25%; The mass concentration of the second sulfuric acid is 25-45%.

[0015] Optionally, the acid leaching temperature is 50-80℃ and the time is 1-5h.

[0016] Optionally, the water washing solution is concentrated and crystallized to obtain sulfate; The sulfate and concentrated sulfuric acid are mixed a second time to obtain regenerated pyrosulfate, which is then returned to the first mixing process.

[0017] Compared with the prior art, the beneficial effects of this application include: The method for activation, transformation, and decomposition of niobium-tantalum concentrate provided in this application uses complex niobium-tantalum concentrate such as titanium-based concentrate as raw material. It involves roasting the niobium-tantalum concentrate with pyrosulfate and sulfuric acid to transform it into simple compounds with simple structures that are easily decomposed. The niobium-tantalum concentrate is then washed with water to allow soluble sulfates to enter the washing solution, while the niobium-tantalum concentrate enters the washing residue. The residue is then leached with low-concentration hydrofluoric acid to allow the niobium-tantalum concentrate to enter the solution system as soluble salts. This method achieves efficient decomposition of difficult-to-decompose niobium-tantalum concentrate, while simultaneously reducing acid mist pollution and equipment corrosion generated during the high-concentration hydrofluoric acid decomposition process and improving the effective utilization rate of hydrofluoric acid. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0019] Figure 1 This is a schematic diagram of the steps involved in the activation, transformation, and decomposition of niobium-tantalum concentrate provided in Example 1. Detailed Implementation

[0020] First, the solution provided in this application will be explained in more detail as follows: This application provides a method for the activation, transformation, and decomposition of niobium-tantalum concentrate, comprising: Niobium-tantalum concentrate, pyrosulfate, and first sulfuric acid are first mixed to obtain a mixture; The mixture is activated and calcined to obtain activated calcined sand; It should be noted that during the activation roasting process, pyrosulfate and sulfuric acid react with niobium-tantalum concentrate to generate corresponding sulfates from niobium-tantalum, and the pyrosulfate decomposes into corresponding soluble sulfates, such as potassium sulfate and sodium sulfate. The activated calcined sand was washed with water to obtain a water washing solution and niobium-tantalum slag. It should be noted that during the water leaching process, the potassium and sodium sulfates generated by the reaction enter the aqueous solution, while niobium and tantalum enter the slag phase; The niobium-tantalum slag is leached in a mixed acid to obtain a niobium-tantalum solution; It should be noted that niobium and tantalum form fluoroniobic acid and fluorotantalic acid, respectively, which then enter the solution; The mixed acid includes hydrofluoric acid and second sulfuric acid.

[0021] In some embodiments, the niobium-tantalum concentrate includes at least one of columbite-iron rutile ore, tantalite-iron rutile ore, columbite-tantalite, and tin-tantalite-iron rutile ore.

[0022] In some embodiments, the proportion of the niobium-tantalum concentrate with a particle size of less than 0.074 mm is ≥80%.

[0023] Optionally, the proportion of niobium-tantalum concentrate with a particle size less than 0.074 mm can be 80%, 85%, 90%, 95%, 100%, or any value between 80% and 100%.

[0024] In some embodiments, the mass ratio of the niobium-tantalum concentrate, the pyrosulfate, and the first sulfuric acid is 1:0.1-0.5:0.2-0.5.

[0025] Optionally, the mass ratio of niobium-tantalum concentrate, pyrosulfate, and primary sulfuric acid can be any value between (1:0.1:0.2), (1:0.2:0.2), (1:0.3:0.2), (1:0.4:0.2), (1:0.5:0.2), (1:0.1:0.3), (1:0.1:0.4), (1:0.1:0.5), or 1:0.1-0.5:0.2-0.5.

[0026] It should be noted that although the amount of pyrosulfate exceeds 0.5%, it does not have a significant impact on the activation and conversion effect, and may even be more beneficial to the activation and conversion of niobium-tantalum concentrate, but its reagent cost increases significantly, which is not conducive to economic development. When the amount of sulfuric acid exceeds 0.5%, the material will be in the form of free liquid or slurry after mixing, which is not conducive to equipment selection and process operation.

[0027] In some embodiments, the pyrosulfate includes at least one of potassium pyrosulfate, sodium pyrosulfate, and ammonium pyrosulfate; And / or, the mass concentration of the first sulfuric acid is 90-98%.

[0028] Optionally, the mass concentration of the first sulfuric acid can be any value between 90%, 92%, 95%, 98%, or 90-98%.

[0029] It should be noted that the lower the sulfuric acid concentration, the higher the energy consumption required during the activation process, and the material is more likely to be in the form of a slurry, which is not conducive to equipment selection and process operation.

[0030] In some embodiments, the activation calcination temperature is 350-600℃ and the time is 10-150 min.

[0031] Optionally, the activation calcination temperature can be any value between 350℃, 400℃, 450℃, 500℃, 550℃, 600℃ or 350-600℃, and the time can be any value between 10 min, 30 min, 60 min, 90 min, 120 min, 150 min or 10-150 min.

[0032] It is important to note that the activation temperature is limited to 350-600℃ and the activation time to 10-150 min. This is mainly because the activation conversion rate is positively correlated with the activation temperature. If the activation temperature is too low, such as 300℃, the driving force for the reaction between pyrosulfate and niobium-tantalum concentrate is insufficient, the reaction rate is slow, and the activation conversion of niobium-tantalum is difficult or extremely slow. If the activation temperature is too high, such as 700℃, the pyrosulfate decomposes quickly, resulting in low efficiency of effective reaction with niobium-tantalum concentrate and reduced utilization of pyrosulfate.

[0033] In some embodiments, the mass ratio of the hydrofluoric acid to the niobium-tantalum concentrate is 0.5-0.8:1; Optionally, the mass ratio of hydrofluoric acid to niobium-tantalum concentrate can be (0.5:1), (0.6:1), (0.7:1), (0.8:1), or any value between 0.5 and 0.8:1; It should be noted that the amount of hydrofluoric acid used has been reduced from 1.0-1.8:1 in the existing production process to 0.5-0.8:1, and the concentration of hydrofluoric acid has been reduced from 33-38% to 16-25%. This is mainly because after the niobium-tantalum concentrate is activated by pyrosulfate and sulfuric acid, niobium-tantalum is more conducive to complexing with hydrofluoric acid to form fluoroniobic acid and fluorotantalic acid solutions, thereby reducing the amount and concentration of hydrofluoric acid used in the leaching process. And / or, the mass ratio of the second sulfuric acid to the niobium-tantalum concentrate is 0.6-1.2:1.

[0034] Optionally, the mass ratio of the second sulfuric acid to the niobium-tantalum concentrate can be (0.6:1), (0.7:1), (0.8:1), (0.9:1), (1:1), (1.1:1), (1.2:1), or any value between 0.6 and 1.2:1.

[0035] In some embodiments, the mass concentration of the hydrofluoric acid is 16-25%; Optionally, the mass concentration of hydrofluoric acid can be any value between 16%, 20%, 23%, 25%, or 16-25%. The mass concentration of the second sulfuric acid is 25-45%.

[0036] Optionally, the mass concentration of the second sulfuric acid can be any value between 25%, 30%, 35%, 40%, 45%, or 25-45%.

[0037] In some embodiments, the acid leaching temperature is 50-80°C and the time is 1-5 hours.

[0038] Optionally, the acid leaching temperature can be any value between 50℃, 60℃, 70℃, 80℃ or 50-80℃, and the time can be any value between 1h, 2h, 3h, 4h, 5h or 1-5h.

[0039] In some embodiments, the water washing solution is concentrated and crystallized to obtain sulfate; The sulfate and concentrated sulfuric acid are mixed a second time to obtain regenerated pyrosulfate, which is then returned to the first mixing process.

[0040] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0041] Example 1 This embodiment provides a method for the activation, transformation and decomposition of niobium-tantalum concentrate, wherein a typical rutile-type niobium-tantalum concentrate is used, the main chemical composition of which is shown in Table 1. Table 1. Main chemical components (%) of typical rutile-type niobium-tantalum concentrate

[0042] The specific steps are as follows: S1: Typical rutile niobium-tantalum concentrate (niobium-tantalum concentrate) is finely ground to 0.074mm with a content of 80%. Then, the niobium-tantalum concentrate, potassium pyrosulfate and sulfuric acid (concentration of 90%) are uniformly mixed in a mass ratio of 1:0.2:0.5. Then, the mixture is placed in a roasting furnace and roasted at 400℃ for 150 minutes in an oxygen-containing atmosphere to obtain activated roasted sand. S2: After washing with room temperature water at a liquid-to-solid ratio of 3 mL:1 g for 1 h, a water washing solution and niobium-tantalum slag were obtained. The niobium-tantalum slag was then acid-leached in a mixed acid, which consisted of hydrofluoric acid (concentration of 16%) and sulfuric acid (concentration of 38%). The mass ratio of hydrofluoric acid to niobium-tantalum concentrate was 0.5:1, and the mass ratio of sulfuric acid to niobium-tantalum concentrate was 1.2:1. The leaching was carried out under stirring conditions at 50 °C for 3 h. S3: The water washing solution obtained in step S2 is subjected to concentrated acid crystallization to obtain sulfate. Then, concentrated sulfuric acid is added to regenerate the salt to obtain pyrosulfate. The pyrosulfate is returned to the roasting process in step S1.

[0043] The method steps for activating, transforming, and decomposing niobium-tantalum concentrate provided in this embodiment are illustrated as follows: Figure 1 As shown.

[0044] The final leaching rates of niobium and tantalum were 99.1% and 98.7%, respectively.

[0045] Example 2 S1: A typical rutile-type niobium-tantalum concentrate (niobium-tantalum concentrate, the same as in Example 1) is finely ground to 0.074 mm with a content of 90%. Then, the niobium-tantalum concentrate, potassium pyrosulfate and sulfuric acid (concentration of 95%) are uniformly mixed at a mass ratio of 1:0.3:0.35. The mixture is then placed in a roasting furnace and roasted at 500°C for 30 minutes under an oxygen-containing atmosphere to obtain activated roasted sand. S2: After washing with room temperature water at a liquid-to-solid ratio of 3 mL:1 g for 0.5 h, a water washing solution and niobium-tantalum slag were obtained. The niobium-tantalum slag was then acid-leached in a mixed acid, which consisted of hydrofluoric acid (concentration of 20%) and sulfuric acid (concentration of 39%). The mass ratio of hydrofluoric acid to niobium-tantalum concentrate was 0.6:1, and the mass ratio of sulfuric acid to niobium-tantalum concentrate was 0.8:1. The mixture was stirred and kept at 80 °C for 2 h.

[0046] Example 3 S1: A typical rutile-type niobium-tantalum concentrate (niobium-tantalum concentrate, the same as in Example 1) was finely ground to 0.074 mm with a particle size of 100%. The niobium-tantalum concentrate, potassium pyrosulfate, and sulfuric acid (concentration of 98%) were then uniformly mixed in a mass ratio of 1:0.5:0.3. The mixture was then placed in a roasting furnace and roasted at 550°C for 60 minutes in an oxygen-containing atmosphere to obtain activated roasted sand. S2: After washing with room temperature water at a liquid-to-solid ratio of 3 mL:1 g for 1 h, a water washing solution and niobium-tantalum slag were obtained. The niobium-tantalum slag was then acid-leached in a mixed acid, which consisted of hydrofluoric acid (concentration of 25%) and sulfuric acid (concentration of 37%). The mass ratio of hydrofluoric acid to niobium-tantalum concentrate was 0.8:1, and the mass ratio of sulfuric acid to niobium-tantalum concentrate was 0.6:1. The mixture was stirred and kept at 60 °C for 1 h.

[0047] Example 4 S1: A typical rutile-type niobium-tantalum concentrate (niobium-tantalum concentrate, the same as in Example 1) was finely ground to 0.074 mm with a particle size of 100%. The niobium-tantalum concentrate, potassium pyrosulfate, and sulfuric acid (concentration of 92%) were then uniformly mixed in a mass ratio of 1:0.3:0.2. The mixture was then placed in a roasting furnace and roasted at 450°C for 120 min in an oxygen-containing atmosphere to obtain activated roasted sand. S2: After washing with room temperature water at a liquid-to-solid ratio of 3 mL:1 g for 1 h, a water washing solution and niobium-tantalum slag were obtained. The niobium-tantalum slag was then acid-leached in a mixed acid, which consisted of hydrofluoric acid (concentration of 23%) and sulfuric acid (concentration of 29%). The mass ratio of hydrofluoric acid to niobium-tantalum concentrate was 0.7:1, and the mass ratio of sulfuric acid to niobium-tantalum concentrate was 0.9:1. The mixture was stirred and kept at 60 °C for 1 h.

[0048] Comparative Example 1 The difference from Example 1 is that no potassium pyrosulfate (pyrosulfate) is added in step S1. Relying solely on concentrated sulfuric acid for roasting lacks the active sulfate ions provided by potassium pyrosulfate, making it difficult to efficiently dissociate the niobium-tantalum mineral lattice, resulting in insufficient mineral activation. The decomposition rates of niobium and tantalum were 88.54% and 87.04%, respectively.

[0049] Comparative Example 2 The difference from Example 1 is that sulfuric acid is not added in step S1. Without the wetting, fluxing, and ion-transfer-enhancing effects of sulfuric acid, the contact between pyrosulfate and the mineral interface is insufficient, resulting in incomplete activation. The decomposition rates of niobium and tantalum are 91.05% and 89.15%, respectively.

[0050] Comparative Example 3 The difference from Example 1 is that in step S1, potassium pyrosulfate (potassium pyrosulfate) is replaced with an equimolar amount of potassium pyrophosphate. Although potassium pyrophosphate and potassium pyrosulfate have similar structures, both being oxyacid condensation salts, the core anionic group is phosphate. Phosphorus has no oxidizing or acidic activation properties and cannot undergo a bonding activation reaction with niobium-tantalum concentrate under roasting conditions. Therefore, it cannot disrupt the stable crystal structure of niobium-tantalum minerals, resulting in extremely poor activation and hindering efficient conversion of niobium and tantalum. In this comparative example, the final leaching rates of niobium and tantalum were 77.92% and 76.58%, respectively.

[0051] Comparative Example 4 The difference from Example 1 is that in step S1, potassium pyrosulfate (potassium pyrosulfate) is replaced with potassium metabisulfite. Potassium metabisulfite is a low-valent sulfur condensate salt with extremely poor thermal stability. At calcination temperatures of 350-600°C, it rapidly decomposes into sulfur dioxide gas and sulfites, making it unable to stably remain and participate in the activation reaction of niobium-tantalum minerals. Furthermore, its decomposition products lack strong acidic activation sites, failing to effectively break the niobium-tantalum chemical bonds and thus unable to achieve mineral activation and transformation, only playing a weak auxiliary role. In this comparative example, the final leaching rates of niobium and tantalum were 82.35% and 80.12%, respectively.

[0052] Comparative Example 5 The difference from Example 1 is that in step S1, potassium persulfate is replaced with potassium pyrosulfate. Although potassium persulfate can generate effective components such as potassium pyrosulfate and sulfate through thermal decomposition, the decomposition rate is too fast and uncontrollable. It decomposes rapidly and completely in the early stage of activation roasting, making it impossible to conduct a continuous and sufficient interfacial reaction with niobium-tantalum concentrate. The effective activation reaction time is extremely short, making it difficult to achieve the stable activation effect of potassium pyrosulfate. In this comparative example, the final leaching rates of niobium and tantalum were 88.12% and 86.96%, respectively.

[0053] Comparative Example 6 The difference from Example 1 is that in step S1, the activation roasting conditions were modified to: a temperature of 300°C and a time of 180 min. The activation roasting temperature was lowered to 300°C, which is below the minimum activation temperature of 350°C specified in this application. The bisulfate and sulfate ions generated by the dissociation of potassium pyrosulfate were insufficiently active, making it difficult to fully destroy the dense crystal lattice of niobium-tantalum minerals. Even with the roasting time extended to 180 min, the degree of mineral activation and transformation remained low. The niobium-tantalum leaching rates were 92.48% and 90.19%, respectively.

[0054] Comparative Example 7 The difference from Example 1 is that in step S2, the mass ratio of hydrofluoric acid to niobium-tantalum concentrate is 0.4:1, and the mass ratio of sulfuric acid to niobium-tantalum concentrate is 1.3:1. The amount of hydrofluoric acid used is lower than the minimum ratio required in this application, which is insufficient to completely complex the niobium and tantalum components in the activated minerals. Excess sulfuric acid, on the contrary, inhibits the fluorine complexation reaction. The niobium-tantalum leaching rates are 90.66% and 89.20%, respectively.

[0055] Comparative Example 8 The difference from Example 1 is that this comparative example uses a conventional hydrofluoric acid-sulfuric acid decomposition method, with the following specific steps: niobium-tantalum concentrate, hydrofluoric acid, and sulfuric acid in a mass ratio of 1:1.8:1.2; hydrofluoric acid concentration of 55%; sulfuric acid concentration of 98%; decomposition temperature of 80℃; and decomposition time of 2 hours. Direct mixed acid decomposition of the raw ore requires high concentrations and large quantities of hydrofluoric acid, and the niobium-tantalum minerals are not lattice activated, resulting in low complexation leaching efficiency. The decomposition leaching rates of niobium and tantalum are 90.54% and 89.63%, respectively.

[0056] The leaching rates of niobium and tantalum and the amount of hydrofluoric acid used by the methods provided in the above embodiments and comparative examples are shown in Table 1.

[0057] Table 1 Data

[0058] analyze: The above tests show that when niobium-tantalum concentrate is decomposed using conventional hydrofluoric acid-sulfuric acid mixed acid, or when potassium pyrosulfate or sulfuric acid is used alone for activation roasting treatment of niobium-tantalum concentrate, or when the mass ratio of hydrofluoric acid to niobium-tantalum concentrate is less than 0.4:1, the leaching rate of niobium and tantalum is around 90%. When activated and converted using pyrosulfate + sulfuric acid, and then leached with low-concentration hydrofluoric acid + sulfuric acid, the leaching rate of both niobium and tantalum can be increased to over 99%.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0060] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A process for the activation conversion decomposition of a niobium tantalum concentrate, characterized in that, include: Niobium-tantalum concentrate, pyrosulfate, and first sulfuric acid are first mixed to obtain a mixture. The mixture is activated and calcined to obtain activated calcined sand; The activated calcined sand was washed with water to obtain a water washing solution and niobium-tantalum slag. The niobium-tantalum slag is leached in a mixed acid to obtain a niobium-tantalum solution; The mixed acid includes hydrofluoric acid and second sulfuric acid.

2. The method of activating, converting and decomposing of tantalum-niobium concentrates according to claim 1, characterized by that, The niobium-tantalum concentrate includes at least one of columbite-iron rutile ore, tantalite-iron rutile ore, columbite-tantalite, and tin-tantalite-iron rutile ore.

3. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to claim 1, characterized in that, The proportion of the niobium-tantalum concentrate with a particle size of less than 0.074 mm is ≥80%.

4. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to claim 1, characterized in that, The mass ratio of the niobium-tantalum concentrate, the pyrosulfate, and the first sulfuric acid is 1:0.1-0.5:0.2-0.

5.

5. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to claim 1, characterized in that, The pyrosulfate includes at least one of potassium pyrosulfate, sodium pyrosulfate and ammonium pyrosulfate; And / or, the mass concentration of the first sulfuric acid is 90-98%.

6. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to claim 1, characterized in that, The activation calcination temperature is 350-600℃, and the time is 10-150 min.

7. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to claim 1, characterized in that, The mass ratio of the hydrofluoric acid to the niobium-tantalum concentrate is 0.5-0.8:1; And / or, the mass ratio of the second sulfuric acid to the niobium-tantalum concentrate is 0.6-1.2:

1.

8. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to claim 1, characterized in that, The mass concentration of the hydrofluoric acid is 16-25%; The mass concentration of the second sulfuric acid is 25-50%.

9. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to claim 1, characterized in that, The acid leaching temperature is 50-80℃, and the time is 1-5 hours.

10. The method for activation, transformation, and decomposition of niobium-tantalum concentrate according to any one of claims 1-9, characterized in that, The water washing solution was concentrated and crystallized to obtain sulfate; The sulfate and concentrated sulfuric acid are mixed a second time to obtain regenerated pyrosulfate, which is then returned to the first mixing process.

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