Method for extracting tantalum and niobium from tantalum-niobium ore through alkali reduction

Abstract

The invention provides a method for extracting tantalum and niobium through tantalum-niobium ore alkali reduction. The method comprises the steps that tantalum-niobium concentrate is ground, and tantalum-niobium ore powder is obtained; dilute sulphuric acid and a reducing agent are added into the tantalum-niobium ore powder for reduction acid leaching impurity removal, solid-liquid separation is conducted, and tantalum-niobium ore obtained after impurity removal is collected; grinding the tantalum-niobium ore subjected to impurity removal to obtain activated tantalum-niobium ore powder; uniformly mixing the activated tantalum-niobium ore powder, potassium sulfite and potassium bicarbonate according to a preset proportion, adding a fluxing agent, and carrying out reduction roasting in a microwave-assisted heating manner; and leaching the roasted product by using pure water to obtain a tantalate-niobate aqueous solution. Iron and manganese in the tantalum-niobium ore are removed by using an acid reduction impurity removal method under a high-temperature condition; and then the tantalum-niobium concentrate is subjected to secondary mechanical activation through a ball mill, alkali reduction roasting is conducted on the tantalum-niobium concentrate added with the fluxing agent through a microwave-assisted heating method, and finally a roasted product is mixed with a leaching aid and leached in sulfuric acid to obtain the tantalum-niobium leaching solution. The whole process is free of fluorination, and harm to the environment can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of tantalum-niobium ore decomposition, and in particular to a method for extracting tantalum and niobium from tantalum-niobium ore by alkali reduction. Background Art

[0002] Tantalum and niobium are vital strategic metals that play an irreplaceable core role in many high-tech industries under the background of the continuous development of the global economy and the continuous progress of science and technology. Due to the high melting point, high strength, biocompatibility, good conductivity and corrosion resistance of tantalum and niobium, as well as the superconducting properties of niobium, they are widely used in the manufacture of aerospace materials, medical bionic equipment, electronic equipment, chemical equipment and superconducting materials.

[0003] Tantalum-niobium ore in my country has a complex structure and is associated with polymetallic deposits, making its decomposition extremely challenging. The main decomposition method currently used in industry is hydrofluoric acid decomposition. High-concentration hydrofluoric acid has good selective dissolution ability for tantalum-niobium ore and can effectively extract tantalum-niobium from the ore. However, hydrofluoric acid is extremely corrosive and has high requirements for the material of the equipment, which increases the investment cost of the equipment. Secondly, fluorine-containing wastewater and waste gas will be produced during the decomposition process of hydrofluoric acid. If not handled properly, it will cause serious pollution to the environment and threaten the ecological balance and human health. Summary of the invention

[0004] The present application provides a method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore, which is beneficial to reducing the usage of hydrofluoric acid or other fluorides and reducing the adverse impact on the ecological environment.

[0005] In a first aspect, an embodiment of the present application provides a method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore, the method comprising:

[0006] Grinding tantalum-niobium concentrate to obtain tantalum-niobium ore powder;

[0007] Adding dilute sulfuric acid and a reducing agent to the tantalum-niobium ore powder to perform reduction acid leaching to remove impurities, separate the solid from the liquid and collect the tantalum-niobium ore after impurities removal;

[0008] Grinding the impurity-removed tantalum-niobium ore to obtain activated tantalum-niobium ore powder;

[0009] The activated tantalum-niobium ore powder, potassium sulfite and potassium bicarbonate are uniformly mixed in a preset ratio, a flux is added, and reduction roasting is performed by microwave-assisted heating;

[0010] The roasted product is leached with pure water to obtain a tantalate niobate aqueous solution.

[0011] According to the first aspect, in a possible implementation, the reducing agent includes reducing sugars, one or more of glucose, fructose, lactose, and maltose.

[0012] According to the first aspect, in a possible implementation manner, the amount of the reducing agent added is 2% to 5% of the mass of the tantalum-niobium ore powder.

[0013] According to the first aspect, in a possible implementation manner, the concentration of the dilute sulfuric acid is 1 mol / L to 6 mol / L.

[0014] According to the first aspect, in a possible implementation, the amount of the dilute sulfuric acid added is 4 to 8 times the mass of the tantalum-niobium ore.

[0015] According to the first aspect, in a possible implementation, in the steps of adding dilute sulfuric acid and a reducing agent to the tantalum-niobium ore powder for reduction acid leaching to remove impurities, and separating the solid and liquid and collecting the tantalum-niobium ore after impurities removal, the reduction acid leaching temperature for impurity removal is 60°C to 95°C, and the reaction time is 2h to 7h.

[0016] According to the first aspect, in a possible implementation, the mass ratio of the input amount of the potassium sulfite and the potassium bicarbonate to the activated tantalum niobium powder is (0.5-2):(0.5-3):1.

[0017] According to the first aspect, in a possible implementation, the co-solvent is potassium metaborate, the mass ratio of the added amount of potassium metaborate to the activated tantalum niobium powder is (0.4-2):1, the roasting temperature is 300°C to 600°C, and the roasting time is 1h to 5h.

[0018] According to the first aspect, in a possible implementation method, in the step of leaching the roasted product with pure water to obtain a tantalate niobate aqueous solution, the mass ratio of the pure water to the roasted product is (10-20):1, the leaching temperature is 20°C to 50°C, the stirring rate is 200r / min to 300r / min, and the leaching time is 0.5h to 2h.

[0019] The method for extracting tantalum and niobium from tantalum-niobium ore by alkali reduction provided in the present application uses a process of first reducing acid leaching to remove impurities and then alkali reducing roasting to decompose the tantalum-niobium ore, which reduces the amount of alkali used while eliminating fluoridation. The method of reducing acid leaching can remove more than 98.9% of the iron and manganese in the tantalum-niobium concentrate, exposing the tantalum and niobium embedded therein, which is beneficial to the subsequent extraction of tantalum and niobium. The present invention uses two ball milling methods to mechanically activate the tantalum-niobium ore, which effectively reduces the temperature required for subsequent reduction roasting. The present invention uses microwave-assisted heating to effectively reduce the time required for roasting and makes the internal heating of the tantalum-niobium concentrate more uniform. The whole process of the present invention is fluoridated, which reduces the harm to the environment and provides strong support and promotion for the tantalum-niobium metallurgical industry to move towards green and achieve sustainable high-quality development. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 The present invention is a schematic flow chart of a method for extracting tantalum and niobium by alkaline reduction of tantalum-niobium ore according to an embodiment; DETAILED DESCRIPTION

[0022] The words "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that may provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0023] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0025] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0026] The present application provides a method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore. As shown in the figure, in some embodiments, the method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore comprises the following steps:

[0027] Step S10, grinding the tantalum-niobium concentrate to obtain tantalum-niobium ore powder;

[0028] The grinding process increases the surface area of ​​the raw materials, which increases the contact area between the reactants in subsequent reactions and improves the reaction efficiency.

[0029] Tantalum-niobium concentrate is used as raw material. Tantalum-niobium concentrate has usually undergone preliminary beneficiation treatment, as shown in Table 1 below. It contains a high proportion of tantalum and niobium elements, with iron and manganese as the main impurities.

[0030] Table 1: Main components of tantalum-niobium ore

[0031] Ta(%) Nb(%) Sn(%) Fe(%) Mn(%) k(％) Si(%) Al(％) 16.754 15.668 3.211 20.983 12.334 0.087 0.739 0.521 Zn(%) Cu(%) Pb(%) Ni(%) Ca(%) Mg(%L) Na(%) B(％) 0.016 0.037 0.012 0.012 1.153 0.031 0.115 0.013

[0032] The tantalum-niobium concentrate is sent to a ball mill for grinding. Specifically, a vibrating ball mill can be used, which is equipped with grinding media, such as zirconium oxide (ZrO2). Zirconium oxide has the characteristics of high hardness, good wear resistance and strong chemical stability, and is suitable for grinding tantalum-niobium concentrate. The vibrating ball mill causes the tantalum-niobium concentrate and the grinding media to collide through vibration, thereby refining the tantalum-niobium concentrate particles. The 200-mesh tantalum-niobium ore is collected by wet screening, and the ground ore powder is screened by wet screening. Wet screening can effectively remove fine mud and impurities in the ore powder while ensuring screening efficiency. The ore powder of this particle size has a large surface area, which provides better contact conditions for subsequent reactions.

[0033] Step S20, adding dilute sulfuric acid and a reducing agent to the tantalum-niobium ore powder to perform reduction acid leaching to remove impurities, separate the solid from the liquid, and collect the tantalum-niobium ore after impurities removal;

[0034] Dilute sulfuric acid and a reducing agent are added to the tantalum-niobium ore powder, and reduction acid leaching is performed at a specific temperature. During this process, the dilute sulfuric acid reacts with the impurities in the ore powder and converts them into soluble substances. At the same time, the reducing agent reduces the high-valent manganese element to a low-valent state, making it easier to separate from the ore powder. After the reaction is completed, the tantalum-niobium ore after impurities are separated from the leaching solution by solid-liquid separation technology (such as filtration, centrifugation, etc.), and the tantalum-niobium ore after impurities are collected.

[0035] Dilute sulfuric acid is selected as the leaching agent with a concentration of 1 mol / L to 6 mol / L. Its addition amount is 4 to 8 times the mass of the tantalum-niobium ore to ensure sufficient reaction.

[0036] The reducing agent is selected from reducing sugars, such as one or more of glucose, fructose, lactose, and maltose. The amount of the reducing agent added is 2% to 5% of the mass of the tantalum-niobium ore powder, and is used to reduce manganese impurities. Specifically, it can reduce tetravalent manganese to divalent manganese, so that the manganese element can be leached and separated from the tantalum-niobium ore in a soluble form.

[0037] The temperature of reducing acid leaching and impurity removal is controlled at 60℃ to 95℃. This temperature range is conducive to the reaction and avoids the energy consumption and safety hazards caused by high temperature.

[0038] The reaction time is 2 hours to 7 hours, ensuring that the reaction proceeds fully while avoiding energy consumption and efficiency loss caused by too long reaction time.

[0039] After the reaction is completed, the decontaminated tantalum-niobium ore is separated from the leaching solution by solid-liquid separation technology (such as filtration, centrifugation, etc.). This step ensures the purity of the decontaminated tantalum-niobium ore and the convenience of subsequent processing.

[0040] The tantalum-niobium ore is collected after impurities are removed and prepared for subsequent processing or extraction steps. At the same time, the leaching solution is treated to recover the useful components or to make it harmless.

[0041] Step S30, grinding the tantalum-niobium ore after impurities removal to obtain activated tantalum-niobium ore powder;

[0042] The grinding process not only further increases the surface area of ​​the raw material, but also causes certain changes in its internal crystal structure, such as lattice distortion, increased defects, etc. These changes make the tantalum-niobium ore more likely to react with the reducing agent during the subsequent reduction roasting process, thereby reducing the required reaction temperature.

[0043] The tantalum-niobium ore obtained in step S20 after impurities removal is used as a raw material for grinding. A suitable ball mill or other grinding equipment is selected to further refine the tantalum-niobium ore. The particle size of the ore powder after grinding can be controlled by adjusting parameters such as the rotation speed of the equipment, the type and amount of grinding media, etc.

[0044] After grinding, the ore powder is separated from the grinding media by screening or other separation techniques. During the screening process, the appropriate mesh size can be selected as needed to control the particle size of the activated tantalum-niobium ore powder. The collected activated tantalum-niobium ore powder has a finer particle size and a larger specific surface area, thereby increasing its activity.

[0045] In practical applications, the ball mill can be a vibration ball mill, the ball milling medium can be zirconium oxide, the filling ratio is (20-60):1, the filling rate is 40% to 70%, and the ball milling time is 3h to 8h.

[0046] Step S40, mixing the activated tantalum-niobium ore powder, potassium sulfite and potassium bicarbonate in a preset ratio, adding a flux, and performing reduction roasting by microwave-assisted heating;

[0047] The activated tantalum-niobium ore powder is reduced and roasted by microwave-assisted heating to further extract the tantalum and niobium elements. The rapidity and uniformity of microwave heating can significantly shorten the roasting time, improve the reaction efficiency, and thus reduce production costs.

[0048] Potassium sulfite and potassium bicarbonate are used as reducing agents to reduce high-valent elements in tantalum-niobium ore to low-valent states for subsequent extraction. The mass ratio of their input amount to activated tantalum-niobium ore powder is (0.5-2): (0.5-3): 1. This ratio range ensures the adequacy of the reducing agent while avoiding the cost increase and environmental pollution caused by excessive addition.

[0049] The flux is potassium metaborate, and the mass ratio of the added amount of potassium metaborate to the activated tantalum niobium powder is (0.4-2):1. The function of the flux is to reduce the roasting temperature, promote the melting and reaction of the raw materials, and thus improve the extraction efficiency.

[0050] The activated tantalum-niobium ore powder, potassium sulfite, potassium bicarbonate and potassium metaborate are mixed evenly in a preset proportion to ensure that the components can fully contact and react during the roasting process.

[0051] Microwave assisted heating is used. Microwave heating is fast and uniform, which can ensure that the raw materials reach the required roasting temperature in a short time, thus significantly shortening the roasting time.

[0052] The roasting temperature is controlled between 300°C and 600°C. This temperature range can ensure the full reaction of the raw materials while avoiding the increase in energy consumption and equipment wear caused by high temperature.

[0053] The calcination time is 1 to 5 hours. A shorter calcination time is beneficial to improving production efficiency, while avoiding the side reactions and product quality degradation that may be caused by long-term high-temperature treatment.

[0054] Step S50: using pure water to leach the roasted product to obtain a tantalate niobate aqueous solution.

[0055] Accurately weigh the calcined product and take an appropriate amount of pure water according to the preset mass ratio. The mass ratio of pure water to calcined product is controlled in the range of (10-20):1. This ratio is intended to ensure that the calcined product can be fully dissolved in pure water while avoiding excessive water that increases the difficulty and cost of subsequent processing.

[0056] The leaching temperature is set between 20°C and 50°C. The appropriate temperature not only helps to improve the leaching efficiency, but also ensures the safety of the operation and avoids safety hazards caused by high temperature.

[0057] Slowly add the roasted product into pure water, start the stirring device at the same time, mix and stir at the preset stirring rate to ensure that the reactants are evenly dispersed in the solution. The stirring rate is maintained between 200r / min and 300r / min. Efficient stirring can accelerate the mass transfer process in the solution, thereby improving the leaching rate and efficiency.

[0058] The leaching time is set to 0.5 hours to 2 hours. Reasonable leaching time can not only ensure sufficient reaction, but also avoid increased energy consumption and possible side reactions caused by too long a time.

[0059] After the reaction is completed, the solid and liquid are separated by filtering or centrifuging, and the collected solution is an aqueous acid salt solution rich in tantalum and niobium elements.

[0060] This embodiment uses a process of first reducing acid leaching to remove impurities and then alkali reduction roasting to decompose the tantalum-niobium ore, which is non-fluoridated and reduces the amount of alkali used. The reduction acid leaching method can remove more than 98.9% of the iron and manganese in the tantalum-niobium concentrate, exposing the tantalum niobium embedded therein, which is beneficial to the subsequent extraction of tantalum niobium. The present invention uses two ball milling methods to mechanically activate the tantalum-niobium ore, which effectively reduces the temperature required for subsequent reduction roasting. The present invention uses microwave-assisted heating to effectively reduce the time required for roasting and make the internal heating of the tantalum-niobium concentrate more uniform. The whole process of the present invention is non-fluoridated, which can reduce the harm to the environment and provide strong support and promotion for the tantalum-niobium metallurgical industry to move towards green and achieve sustainable high-quality development.

[0061] The present application is described below by way of examples.

[0062] In a first embodiment, the method for extracting tantalum and niobium from tantalum-niobium ore by alkali reduction comprises the following steps:

[0063] (1) grinding the tantalum-niobium ore using a ball mill and collecting the 200-mesh tantalum-niobium ore using a wet sieving method;

[0064] (2) using dilute sulfuric acid and a reducing agent to perform reduction acid leaching on the tantalum-niobium concentrate to remove the associated elements of iron and manganese, separate the solid and liquid, and collect the solid, wherein the concentration of the dilute sulfuric acid is 2 mol / L, and the mass ratio of the added amount to the tantalum-niobium ore is 7:1;

[0065] The reducing agent is glucose, the addition amount is 2% of the mass of the tantalum-niobium ore, the reduction acid leaching impurity removal temperature is 80°C, the reaction time is 3h, and the iron removal rate in the tantalum-niobium ore is 99.51% and the manganese removal rate is 98.63% after testing;

[0066] (3) placing the tantalum-niobium ore from which iron and manganese have been removed into a high-energy vibration ball mill for secondary ball milling to obtain activated tantalum-niobium ore powder, wherein the ball milling medium is zirconium oxide, the filling ratio is 30:1, the filling rate is 40%, and the ball milling time is 6 hours;

[0067] (4) The activated tantalum-niobium ore powder is uniformly mixed with potassium sulfite and potassium bicarbonate, and then a flux is added, and reduction roasting is performed by microwave-assisted heating, wherein the potassium sulfite is used as a reducing agent, and the mass ratio of the input amount of potassium sulfite and potassium bicarbonate to the activated tantalum-niobium powder is 0.5:2:1; the co-solvent is potassium metaborate, and the mass ratio of the input amount of the co-solvent to the activated tantalum-niobium powder is 0.5:1, the roasting temperature is 450° C., and the roasting time is 2 h;

[0068] (5) The calcined product is leached with pure water to obtain a tantalate niobate aqueous solution, wherein the ratio of pure water to the calcined product is 10:1, the leaching temperature is 50°C, the stirring rate is 300 r / min, the leaching time is 1 h, and the tantalum-niobium leaching solution is tested, and the tantalum leaching rate is 91.28%, and the niobium leaching rate is 97.56%.

[0069] In a second embodiment, the method for extracting tantalum and niobium from tantalum-niobium ore by alkali reduction comprises the following steps:

[0070] (1) grinding the tantalum-niobium ore using a ball mill and collecting the 200-mesh tantalum-niobium ore using a wet sieving method;

[0071] (2) using dilute sulfuric acid and a reducing agent to perform reduction acid leaching on the tantalum-niobium concentrate to remove the associated elements of iron and manganese, separate the solid and liquid, and collect the solid, wherein the concentration of the dilute sulfuric acid is 3 mol / L, and the mass ratio of the added amount to the tantalum-niobium ore is 6:1;

[0072] The reducing agent is glucose, the addition amount is 2.5% of the mass of the tantalum-niobium ore, the reduction acid leaching impurity removal temperature is 90°C, the reaction time is 4h, and the iron removal rate in the tantalum-niobium ore is 99.66% and the manganese removal rate is 98.91% after testing;

[0073] (3) placing the tantalum-niobium ore from which iron and manganese have been removed into a high-energy vibration ball mill for secondary ball milling to obtain activated tantalum-niobium ore powder, wherein the ball milling medium is zirconium oxide, the filling ratio is 40:1, the filling rate is 50%, and the ball milling time is 5 hours;

[0074] (4) The activated tantalum-niobium ore powder is uniformly mixed with potassium sulfite and potassium bicarbonate, and then a flux is added, and reduction roasting is performed by microwave-assisted heating, wherein potassium sulfite is used as a reducing agent, and the mass ratio of the input amount of potassium sulfite and potassium bicarbonate to the activated tantalum-niobium powder is 0.8:2.0:1; the co-solvent is potassium metaborate, and the mass ratio of the input amount of the co-solvent to the activated tantalum-niobium powder is 0.6:1, the roasting temperature is 500° C., and the roasting time is 2 h;

[0075] (5) The calcined product was leached with pure water to obtain a tantalate niobate aqueous solution, wherein the ratio of pure water to the calcined product was 15:1, the leaching temperature was 40°C, the stirring rate was 200 r / min, and the leaching time was 1.5 h. The tantalum-niobium leaching solution was tested, and the tantalum leaching rate was 91.88%, and the niobium leaching rate was 98.16%.

[0076] In a third embodiment, a method for extracting tantalum and niobium from tantalum-niobium ore by alkali reduction comprises the following steps:

[0077] (1) grinding the tantalum-niobium ore using a ball mill and collecting the 200-mesh tantalum-niobium ore using a wet sieving method;

[0078] (2) using dilute sulfuric acid and a reducing agent to perform reduction acid leaching on the tantalum-niobium concentrate to remove the associated elements of iron and manganese, separate the solid and liquid, and collect the solid, wherein the concentration of the dilute sulfuric acid is 1 mol / L, and the mass ratio of the added amount to the tantalum-niobium ore is 8:1;

[0079] The reducing agent is glucose, the addition amount is 4% of the mass of the tantalum-niobium ore, the reduction acid leaching impurity removal temperature is 85°C, the reaction time is 5h, and the iron removal rate in the tantalum-niobium ore is 99.21% and the manganese removal rate is 98.34% after testing;

[0080] (3) placing the tantalum-niobium ore from which iron and manganese have been removed into a high-energy vibration ball mill for secondary ball milling to obtain activated tantalum-niobium ore powder, wherein the ball milling medium is zirconium oxide, the filling ratio is 35:1, the filling rate is 60%, and the ball milling time is 4.5 h;

[0081] (4) The activated tantalum-niobium ore powder is uniformly mixed with potassium sulfite and potassium bicarbonate, and then a flux is added, and reduction roasting is performed by microwave-assisted heating, wherein potassium sulfite is used as a reducing agent, and the mass ratio of the input amount of potassium sulfite and potassium bicarbonate to the activated tantalum-niobium powder is 0.8:1.5:1; the co-solvent is potassium metaborate, and the mass ratio of the input amount of the co-solvent to the activated tantalum-niobium powder is 1:1, the roasting temperature is 400° C., and the roasting time is 3 hours;

[0082] (5) The calcined product was leached with pure water to obtain a tantalate niobate aqueous solution, wherein the ratio of pure water to the calcined product was 13:1, the leaching temperature was 40°C, the stirring rate was 300 r / min, and the leaching time was 2 h. The tantalum niobium leaching solution was tested, and the tantalum leaching rate was 88.22%, and the niobium leaching rate was 96.08%.

[0083] The applicant declares that the present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the method of the present invention, addition of auxiliary steps, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for extracting tantalum and niobium by alkaline reduction of tantalum-niobium ore, characterized in that: The method comprises: Grinding tantalum-niobium concentrate to obtain tantalum-niobium ore powder; Adding dilute sulfuric acid and a reducing agent to the tantalum-niobium ore powder to perform reduction acid leaching to remove impurities, separate the solid from the liquid and collect the tantalum-niobium ore after impurities removal; Grinding the impurity-removed tantalum-niobium ore to obtain activated tantalum-niobium ore powder; The activated tantalum-niobium ore powder, potassium sulfite and potassium bicarbonate are uniformly mixed in a preset ratio, a flux is added, and reduction roasting is performed by microwave-assisted heating; The roasted product is leached with pure water to obtain a tantalate niobate aqueous solution.

2. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 1, characterized in that: The reducing agent includes reducing sugars, one or more of glucose, fructose, lactose and maltose.

3. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 2, characterized in that: The amount of the reducing agent added is 2% to 5% of the mass of the tantalum-niobium ore powder.

4. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 1, characterized in that: The concentration of the dilute sulfuric acid is 1 mol / L to 6 mol / L.

5. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 1, characterized in that: The amount of dilute sulfuric acid added is 4 to 8 times the mass of the tantalum-niobium ore.

6. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 3, characterized in that: In the steps of adding dilute sulfuric acid and a reducing agent to the tantalum-niobium ore powder for reduction acid leaching and impurity removal, solid-liquid separation and collecting the tantalum-niobium ore after impurity removal, the reduction acid leaching and impurity removal temperature is 60° C. to 95° C., and the reaction time is 2 h to 7 h.

7. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 3, characterized in that: The mass ratio of the input amount of the potassium sulfite and the potassium bicarbonate to the activated tantalum niobium powder is (0.5-2):(0.5-3):

1.

8. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 3, characterized in that: The auxiliary solvent is potassium metaborate, and the mass ratio of the addition amount of the potassium metaborate to the activated tantalum niobium powder is (0.4-2):

1. The roasting temperature is 300°C to 600°C, and the roasting time is 1h to 5h.

9. The method for extracting tantalum and niobium by alkali reduction of tantalum-niobium ore according to claim 3, characterized in that: In the step of using pure water to leaching the roasted product to obtain a tantalate niobate aqueous solution, the mass ratio of the pure water to the roasted product is (10-20):1, the leaching temperature is 20°C to 50°C, the stirring rate is 200r / min-300r / min, and the leaching time is 0.5h to 2h.

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