Production method and application of niobium hydroxide in tantalum-niobium hydrometallurgy

Abstract

The invention provides a production method and application of niobium hydroxide in tantalum-niobium hydrometallurgy, and relates to the technical field of tantalum-niobium hydrometallurgy. Tantalum-niobium ore is ground to obtain tantalum-niobium particles; hydrofluoric acid and sulfuric acid are added into the tantalum-niobium particles for a decomposition reaction, and decomposition liquid containing tantalum and niobium is obtained; carrying out acid regulation on the decomposition liquid containing tantalum and niobium, and then extracting with MIBK (Methyl Isobutyl Ketone) to obtain a loaded organic phase containing tantalum and niobium; carrying out acid pickling on the tantalum-niobium loaded organic phase to obtain a tantalum-niobium loaded phase; extracting the tantalum-niobium load phase by using an anti-niobium solution to obtain a fluoroniobic acid solution; adding urea into the fluoroniobic acid solution to carry out neutralization reaction, and filtering to obtain a niobium hydroxide crude product; leaching the niobium hydroxide crude product, and drying after leaching to obtain a niobium hydroxide product; the urea is used as the neutralizer for neutralization, liquid ammonia is not used any more, the production risk is greatly reduced, and the safety production cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of tantalum-niobium hydrometallurgy, and specifically relates to a production method of niobium hydroxide in tantalum-niobium hydrometallurgy and application thereof. Background Art

[0002] In the case of co-existence of tantalum and niobium raw materials, most areas in China adopt tantalum-niobium hydrometallurgy, using HF and H2SO4 for leaching, and then using MIBK or 2-octanol for tantalum-niobium extraction and separation. Niobium is pickled with sulfuric acid, and after pickling, niobium is stripped into sulfuric acid solution to generate fluoroniobic acid solution, which is then neutralized with vaporized ammonia to generate niobium hydroxide. Liquid ammonia is required for neutralization in this process, but liquid ammonia has high safety requirements during storage and use, resulting in increased safety production costs.

[0003] In the prior art, for example, a Chinese invention patent with application number 202410628892.3 discloses a neutralization precipitation process for ultrafine niobium oxide, and the specific process steps of the invention include: acidity adjustment: adjusting the pH of the fluoroniobate solution to 1.0-1.5 to obtain an acidified niobium solution; neutralization reaction: adding a neutralizing agent to the acidified niobium solution under stirring to adjust the pH of the acidified niobium solution to 9.0-9.5, and then transferring it to a filter press. After the feeding is completed, the washing water is turned on for washing until the mass concentration of the F element in the washing liquid is less than 500 mg / L; the filter cake in the filter press is unloaded and dried to obtain a precursor for preparing ultrafine niobium oxide; the neutralizing agent is selected from a combination of ammonium bicarbonate solution and sodium hydroxide solution; in the above-mentioned prior art, a combination of ammonium bicarbonate solution and sodium hydroxide solution is used as a liquid phase neutralization precipitant to obtain ultrafine niobium oxide, and liquid ammonia is no longer used, so that the cost of safe production is reduced, but the impurities of other elements introduced above affect the quality of the prepared product. Summary of the invention

[0004] In view of this, the present invention provides a method for producing niobium hydroxide in tantalum-niobium hydrometallurgy, which can reduce costs and does not introduce other impurities.

[0005] It is also necessary to provide an application of a method for producing niobium hydroxide in tantalum-niobium hydrometallurgy.

[0006] The technical solution adopted by the present invention to solve its technical problem is: A method for producing niobium hydroxide in tantalum-niobium hydrometallurgy comprises the following steps: Grinding: Grinding tantalum-niobium ore to obtain tantalum-niobium particles; Decomposition: adding hydrofluoric acid and sulfuric acid to the tantalum-niobium particles to carry out a decomposition reaction to obtain a decomposition liquid containing tantalum-niobium; Extraction: The decomposition solution containing tantalum and niobium is subjected to acid adjustment, and then extracted with MIBK to obtain an organic phase loaded with tantalum and niobium; Acid washing: acid washing the organic phase containing tantalum and niobium load, and obtaining the tantalum and niobium load phase after acid washing; Reverse niobium: The tantalum-niobium loaded phase is extracted with a reverse niobium solution to obtain a fluoroniobate acid solution; Neutralization: adding urea to the fluoroniobic acid solution for neutralization reaction, and filtering to obtain crude niobium hydroxide; Drying: The crude niobium hydroxide is eluted and then dried to obtain the niobium hydroxide product.

[0007] Preferably, the step of adding urea to the fluoroniobic acid solution for neutralization reaction comprises the following steps: S1: decomposing urea at a predetermined temperature to obtain decomposition gas; S2: adding the decomposed gas into the fluoroniobic acid solution for neutralization reaction, and filtering after the reaction to obtain a niobium hydroxide product.

[0008] Preferably, in step S1, the predetermined temperature is 120°C to 180°C.

[0009] Preferably, the ratio of tantalum niobium to hydrofluoric acid and sulfuric acid in the tantalum niobium ore is 1kg tantalum niobium: 1.5L-1.8L HF: 0.2L-0.3L H2SO4, and the mass ratio of niobium in the fluoroniobic acid to the urea is greater than or equal to 1:1.5.

[0010] Preferably, in the grinding step, the particle size of the tantalum-niobium particles is -200 mesh to -300 mesh.

[0011] Preferably, in the decomposition step, the decomposition reaction needs to be kept warm, the warming temperature is 80° C. to 95° C., and the decomposition time is more than 6 hours.

[0012] Preferably, in the extraction step, after the acid adjustment of the decomposition liquid containing tantalum and niobium, the acidity of sulfuric acid is 3.75-4.25 mol / L, and the acidity of hydrofluoric acid is 5.5 mol / L-6.5 mol / L. After the acid adjustment, it is extracted with MIBK, and the tantalum and niobium content ratio in the decomposition liquid is (1-5): (1-5), and the extraction level is above 10 levels, so as to obtain an organic phase loaded with tantalum and niobium.

[0013] Preferably, in the reverse niobium step, the acidity of the reverse niobium solution is 0.7-0.8 mol / L, the volume ratio of the tantalum-niobium loaded phase to the reverse niobium solution is 3:(3-1), and the extraction level is above 6.

[0014] Preferably, in the drying step, the crude niobium hydroxide is washed to a pH of 6-6.5. The application of the method for producing niobium hydroxide in tantalum-niobium hydrometallurgy as described above further comprises a reduction step: roasting the niobium hydroxide product to obtain niobium oxide.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a method for producing niobium hydroxide in tantalum-niobium hydrometallurgy, comprising the steps of grinding tantalum-niobium ore to obtain tantalum-niobium particles; adding hydrofluoric acid and sulfuric acid to the tantalum-niobium particles for decomposition reaction to obtain a decomposition liquid containing tantalum-niobium; acid-adjusting the decomposition liquid containing tantalum-niobium, extracting it with MIBK after acid adjustment to obtain an organic phase loaded with tantalum-niobium; acid-washing the organic phase loaded with tantalum-niobium to obtain a tantalum-niobium loaded phase; extracting the tantalum-niobium loaded phase with a reverse niobium liquid to obtain a fluoroniobium acid solution; adding urea to the fluoroniobium acid solution for neutralization reaction, filtering to obtain a crude niobium hydroxide product; and The crude niobium oxide is eluted and then dried to obtain a niobium hydroxide product. By using urea as a neutralizing agent for neutralization, on the one hand, liquid ammonia is no longer used, which greatly reduces the production risk and the cost of safe production, thereby reducing the cost of safe production. On the other hand, by using urea as a neutralizing agent for the neutralization reaction, foreign impurity elements will not be introduced without affecting the formation of niobium hydroxide, and the quality of niobium hydroxide will not be affected. On the other hand, by using urea as a neutralizing agent, the particle size of the prepared niobium hydroxide is finer and the quality is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the particle size distribution diagram of niobium hydroxide prepared in Example 1.

[0017] Figure 2 This is the particle size detection distribution diagram of niobium hydroxide prepared in Comparative Example 1. DETAILED DESCRIPTION

[0018] The technical solutions and technical effects of the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings of the present invention.

[0019] A method for producing niobium hydroxide in tantalum-niobium hydrometallurgy comprises the following steps: Grinding: Grind the tantalum-niobium ore to obtain tantalum-niobium particles, so as to achieve good decomposition and leaching effect of tantalum-niobium; Specifically, the tantalum-niobium content in the tantalum-niobium ore is about 40%-50%.

[0020] Decomposition: adding hydrofluoric acid and sulfuric acid to the tantalum-niobium particles to carry out a decomposition reaction, so that the tantalum-niobium raw materials in the tantalum-niobium particles react with the hydrofluoric acid to generate fluorotantalic acid and fluorooxyniobic acid, so as to separate them from other impurities in the ore, and obtain a decomposition liquid containing tantalum-niobium; Extraction: The decomposition liquid containing tantalum and niobium is subjected to acid adjustment, and then extracted with MIBK, and fluorotantalate and fluorooxyniobate in the decomposition liquid are extracted into the MIBK extractant to extract tantalum and niobium from the decomposition liquid containing fluoride salt and sulfate, thereby obtaining an organic phase loaded with tantalum and niobium; Acid washing: acid washing the organic phase containing tantalum and niobium load, and obtaining the tantalum and niobium load phase after acid washing; Specifically, the metal impurity content in the organic phase loaded with tantalum and niobium is reduced by using sulfuric acid; Reverse niobium: The tantalum-niobium loaded phase is extracted with a reverse niobium solution to separate the fluorotantalate and fluorooxyniobate in the loaded phase to obtain a fluoroniobate solution; Neutralization: adding urea to the fluoroniobic acid solution for neutralization reaction, and filtering to obtain crude niobium hydroxide; Drying: The crude niobium hydroxide is eluted and then dried to obtain the niobium hydroxide product.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a method for producing niobium hydroxide in tantalum-niobium hydrometallurgy, comprising the steps of grinding tantalum-niobium ore to obtain tantalum-niobium particles; adding hydrofluoric acid and sulfuric acid to the tantalum-niobium particles for decomposition reaction to obtain a decomposition liquid containing tantalum-niobium; acid-adjusting the decomposition liquid containing tantalum-niobium, extracting it with MIBK after acid adjustment to obtain an organic phase loaded with tantalum-niobium; acid-washing the organic phase loaded with tantalum-niobium to obtain a tantalum-niobium loaded phase; extracting the tantalum-niobium loaded phase with a reverse niobium liquid to obtain a fluoroniobium acid solution; adding urea to the fluoroniobium acid solution for neutralization reaction, filtering to obtain a crude niobium hydroxide product; and The crude niobium oxide is eluted and then dried to obtain a niobium hydroxide product. By using urea as a neutralizing agent for neutralization, on the one hand, liquid ammonia is no longer used, which greatly reduces the production risk and the cost of safe production, thereby reducing the cost of safe production. On the other hand, by using urea as a neutralizing agent for the neutralization reaction, foreign impurity elements will not be introduced without affecting the formation of niobium hydroxide, and the quality of niobium hydroxide will not be affected. On the other hand, by using urea as a neutralizing agent, the particle size of the prepared niobium hydroxide is finer and the quality is better.

[0022] Furthermore, the process of adding urea to the fluoroniobic acid solution for neutralization reaction comprises the following steps: S1: decomposing urea at a predetermined temperature to obtain decomposition gas; S2: adding the decomposed gas to the fluoroniobic acid solution for neutralization reaction, filtering when the pH after the reaction is 6-9 to complete the reaction and ensure the yield, and filtering to obtain the niobium hydroxide product.

[0023] Urea must first be decomposed to obtain decomposition gas, which is then neutralized with fluoroniobic acid or fluorooxyniobic acid to generate niobium hydroxide to reduce the impurity content. If urea is directly added to the fluoroniobic acid solution, white precipitate will be generated after thermal decomposition of the urea, resulting in a high impurity content in the niobium hydroxide.

[0024] Furthermore, in the step S1, the predetermined temperature is 120°C to 180°C.

[0025] Specifically, the fluoroniobic acid solution is transferred to a neutralization tank, and urea is added to the urea decomposition equipment. Urea is decomposed into ammonia and carbon dioxide at 120-180°C. The ammonia and carbon dioxide enter the neutralization tank through a polyethylene pipe. The ammonia reacts with the fluoroniobic acid and is filtered to obtain niobium hydroxide. On the one hand, the decomposed gas is gradually added to the fluoroniobic acid solution, so that the neutralization reaction is sufficient. On the other hand, the decomposed ammonia and carbon dioxide themselves are preheated to carry the temperature. After the ammonia and carbon dioxide enter, they will not cause temperature fluctuations in the neutralization reaction process, so that the neutralization reaction temperature is stable, and the prepared niobium hydroxide has finer particle size and better quality.

[0026] Furthermore, the ratio of tantalum niobium to hydrofluoric acid and sulfuric acid in the tantalum niobium ore is 1kg tantalum niobium: 1.5L-1.8L HF: 0.2L-0.3L H2SO4, and the mass ratio of niobium in the fluoroniobic acid to the urea is greater than or equal to 1:1.5.

[0027] Furthermore, in the grinding step, the particle size of the tantalum-niobium particles is -200 mesh to -300 mesh, wherein the particle size is a negative value because the standard size of the sieve is 200 mesh and 300 mesh, indicating that there are 200 and 300 sieve holes per inch of the sieve, respectively. A minus sign in front of the mesh number indicates that the mesh hole of that mesh number can pass through, i.e., the particle size is smaller than the mesh hole size.

[0028] Furthermore, in the decomposition step, the decomposition reaction needs to be kept warm at a temperature of 80°C to 95°C to prevent the hydrofluoric acid from volatilizing and to allow the tantalum-niobium particles to react violently with the hydrofluoric acid. The decomposition time is more than 6 hours.

[0029] Furthermore, in the extraction step, after the acidity of the decomposition liquid containing tantalum and niobium is adjusted, the acidity of sulfuric acid is 3.75-4.25 mol / L, and the acidity of hydrofluoric acid is 5.5 mol / L-6.5 mol / L. If the acidity of the decomposition liquid containing tantalum and niobium is low, the acidity of sulfuric acid is adjusted with industrial sulfuric acid, and the acidity of hydrofluoric acid is adjusted with industrial hydrofluoric acid. If the acidity is high, it is adjusted with pure water. After acid adjustment, it is extracted with MIBK. The tantalum and niobium content ratio in the decomposition liquid is (1-5): (1-5), and the extraction level is above 10 levels. An organic phase loaded with tantalum and niobium is obtained to prevent the poor separation effect of tantalum and niobium in the loaded organic phase, resulting in high tantalum in niobium.

[0030] Furthermore, in the reverse niobium step, the acidity of the reverse niobium solution is 0.7-0.8 mol / L, the volume ratio of the tantalum-niobium loaded phase to the reverse niobium solution is 3:(3-1), and the extraction level is above level 6.

[0031] Specifically, the inverse niobium solution is a dilute sulfuric acid solution with an acidity of 0.7-0.8 mol / L.

[0032] Furthermore, in the drying step, the crude niobium hydroxide is washed to a pH of 6-6.5, and then dried in an oven at 90° C. to 120° C. to obtain a niobium hydroxide product.

[0033] The application of the method for producing niobium hydroxide in tantalum-niobium hydrometallurgy as described above further comprises a reduction step: roasting the niobium hydroxide product to obtain niobium oxide.

[0034] For ease of understanding, the present invention is further illustrated by the following examples: Embodiment 1:

[0035] Grinding: 6000kg of tantalum-niobium ore is added into Raymond mill for grinding. After grinding, the particle size of tantalum-niobium ore is between -200 and -300 mesh, and tantalum-niobium particles are obtained.

[0036] Decomposition: Add the obtained 6000kg tantalum-niobium particles into the decomposition reactor, and then use a compression pump to deliver 8200L of hydrofluoric acid and 2500L of sulfuric acid into the decomposition reactor for decomposition. During the decomposition process, maintain 80℃~95℃ for more than 6h to obtain a decomposition liquid containing tantalum and niobium.

[0037] Extraction: The above tantalum-niobium-containing decomposition liquid is acidified to 3.75-4.25 mol / L sulfuric acid acid and 5.5-6.5 mol / L hydrofluoric acid acid, and then extracted with MIBK. The tantalum-niobium content ratio in the decomposition liquid is (1-5): (1-5), and the extraction level is above 10, to obtain an organic phase loaded with tantalum-niobium.

[0038] Acid washing: The organic phase loaded with tantalum and niobium obtained above is acid washed with 4-4.5 mol / L dilute sulfuric acid solution. The acidity of the acid washing solution is 4-4.5 mol / L. The volume ratio of the organic phase loaded with tantalum and niobium to the acid washing solution is (3-4):1. The extraction level is above 6. After acid washing, the tantalum and niobium loaded phase is obtained.

[0039] De-niobium: The tantalum-niobium loaded phase obtained above is extracted with de-niobium liquid. The acidity of the de-niobium liquid is 0.7-0.8 mol / L of dilute sulfuric acid solution. The acidity of the de-niobium liquid is 0.7-0.8 mol / L. The volume ratio of the tantalum-niobium loaded phase to the de-niobium liquid is 3:(3~1). The extraction level is above 6. After de-niobium, a fluoroniobic acid solution is obtained.

[0040] Neutralization: The fluoroniobic acid solution obtained above is transferred to a neutralization tank, 1000 kg of urea is added to the urea decomposition equipment, the decomposition temperature is 120°C, and the urea decomposition exhaust port is connected to the neutralization tank with a polyethylene pipe. The ammonia produced after urea decomposition reacts with the fluoroniobic acid to obtain niobium hydroxide after filtering at pH 8-9.

[0041] Drying: The niobium hydroxide obtained above was washed with pure water to a pH of 6, and dried in an oven at 90° C. to obtain a niobium hydroxide product. Embodiment 2:

[0042] In the neutralization step, the decomposition temperature is 140° C.; in the drying step, the drying temperature is 100° C., and the other steps are the same as those in Example 1. Embodiment 3:

[0043] In the neutralization step, the decomposition temperature is 160°C; in the drying step, the drying temperature is 110°C.

[0044] Reduction step: calcining niobium hydroxide at 800°C-900°C for 3-4 hours to obtain niobium pentoxide.

[0045] The other steps are the same as those in Example 1.

[0046] Comparative Example 1: Neutralization: The fluoroniobic acid solution obtained above is transferred to a neutralization tank, and liquid ammonia is transported to a vaporizer through a pipeline. The vaporizer converts the liquid ammonia into gaseous ammonia, and the gaseous ammonia is introduced into the fluoroniobic acid solution and transferred to a neutralization tank for neutralization reaction. After neutralization to pH 8-9 and filtering, niobium hydroxide is obtained.

[0047] The other steps are the same as those in Example 1.

[0048] The niobium hydroxide obtained in Examples 1-3 and Comparative Example 1 was detected by DC arc atomic emission spectrometry using a DC arc spectrometer, and the detection data obtained were shown in Table 1.

[0049] Table 1

[0050] As can be seen from Table 1, the preparation of niobium hydroxide by decomposing urea is feasible in the present invention, and can reach the level of preparation using liquid ammonia without introducing any influence of foreign impurities.

[0051] The niobium hydroxide obtained in Example 1 and Comparative Example 1 was tested for particle size. The test results are as follows: Figure 1 , Figure 2 As shown by Figure 1 , Figure 2 It can be seen that the particle size distribution of niobium hydroxide prepared by decomposing urea in the present invention is finer.

[0052] What is disclosed above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for producing niobium hydroxide in tantalum-niobium hydrometallurgy, characterized in that: The following steps are involved: Grinding: Grinding tantalum-niobium ore to obtain tantalum-niobium particles; Decomposition: adding hydrofluoric acid and sulfuric acid to the tantalum-niobium particles to carry out a decomposition reaction to obtain a decomposition liquid containing tantalum-niobium; Extraction: The decomposition solution containing tantalum and niobium is subjected to acid adjustment, and then extracted with MIBK to obtain an organic phase loaded with tantalum and niobium; Acid washing: acid washing the organic phase containing tantalum and niobium load, and obtaining the tantalum and niobium load phase after acid washing; Reverse niobium: The tantalum-niobium loaded phase is extracted with a reverse niobium solution to obtain a fluoroniobate acid solution; Neutralization: adding urea to the fluoroniobic acid solution for neutralization reaction, and filtering to obtain crude niobium hydroxide; Drying: The crude niobium hydroxide is eluted and then dried to obtain the niobium hydroxide product.

2. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: The process of adding urea to the fluoroniobic acid solution for neutralization reaction comprises the following steps: S1: decomposing urea at a predetermined temperature to obtain decomposition gas; S2: adding the decomposed gas into the fluoroniobic acid solution for neutralization reaction, and filtering after the reaction to obtain a niobium hydroxide product.

3. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 2, characterized in that: In the step S1, the predetermined temperature is 120°C to 180°C.

4. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: The ratio of tantalum niobium to hydrofluoric acid and sulfuric acid in the tantalum niobium ore is 1kg tantalum niobium: 1.5L-1.8L HF: 0.2L-0.3L H2SO4, and the mass ratio of niobium in the fluoroniobic acid to the urea is greater than or equal to 1:1.

5.

5. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: In the grinding step, the particle size of the tantalum-niobium particles is -200 mesh to -300 mesh.

6. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: In the decomposition step, the decomposition reaction needs to be kept warm, the warming temperature is 80° C. to 95° C., and the decomposition time is more than 6 hours.

7. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: In the extraction step, after the acid adjustment of the decomposition liquid containing tantalum and niobium, the acidity of sulfuric acid is 3.75-4.25 mol / L, and the acidity of hydrofluoric acid is 5.5 mol / L-6.5 mol / L. After the acid adjustment, it is extracted with MIBK, and the tantalum and niobium content ratio in the decomposition liquid is (1-5): (1-5), and the extraction level is above 10 levels, so as to obtain an organic phase loaded with tantalum and niobium.

8. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: In the reverse niobium step, the acidity of the reverse niobium solution is 0.7-0.8 mol / L, the volume ratio of the tantalum-niobium loaded phase to the reverse niobium solution is 3:(3-1), and the extraction level is above 6.

9. The method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: In the drying step, the crude niobium hydroxide is washed to a pH of 6-6.

5.

10. The use of the method for producing niobium hydroxide in tantalum-niobium hydrometallurgy according to claim 1, characterized in that: The method also includes a reduction step: roasting the niobium hydroxide product to obtain niobium oxide.

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