A method for separating antimony and bismuth by wet process

Abstract

The present application belongs to the technical field of metallurgical separation, and relates to a method for separating antimony and bismuth by wet process, which comprises the following steps: (1) subjecting a mixture of antimony and bismuth to a first leaching treatment with a tartrate-based leaching agent, and obtaining an antimony-rich liquid and a bismuth-rich material after solid-liquid separation; (2) subjecting an acid source to a second leaching treatment with the antimony-rich liquid obtained in step (1), and obtaining a post-sedimentation antimony liquid and an antimony-rich material after solid-liquid separation; and the post-sedimentation antimony liquid is recycled to the first leaching treatment in step (1). The present application solves the problems of large amount of wastewater and low separation efficiency in the traditional hydrolytic separation of antimony and bismuth, and the leaching agent can be recycled after being enriched with antimony by precipitation.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical separation technology and relates to a method for wet separation of antimony and bismuth. Background Technology

[0002] Antimony and bismuth are two important non-ferrous metals widely used in alloys, semiconductors, pharmaceuticals, and chemicals. Because they often coexist in nature and have very similar properties, the efficient separation of antimony and bismuth has always been a pressing problem in hydrometallurgy.

[0003] Currently, antimony-bismuth mixtures are generally separated using hydrochloric acid leaching, taking advantage of the differences in the hydrolysis behavior of antimony and bismuth at different pH values. For example, CN103397180A discloses a method for recovering antimony, bismuth, and copper from complex materials, using sulfuric acid and sodium chloride coordination leaching to achieve bismuth and antimony leaching, followed by separate hydrolysis to precipitate bismuth and antimony. However, this method suffers from problems such as large wastewater volume, severe corrosion of equipment by chloride ions, and low separation efficiency. Furthermore, the resulting low-antimony-rich bismuth and low-bismuth-rich antimony slag still require further treatment. CN118639018A discloses a method for separating and recovering antimony and bismuth from copper, arsenic, antimony, and bismuth-containing materials. This method utilizes the characteristic that trivalent antimony is soluble in excess alkali sulfide to form thioantimonite while trivalent bismuth is insoluble, adding liquid alkali and sodium hydrosulfide for selective leaching of antimony. However, this method easily generates highly toxic hydrogen sulfide gas, resulting in poor operational safety; it also requires a large amount of alkaline sulfidation reagent, leading to high costs; and the generated sulfur-containing waste liquid or residue is complex to treat and prone to secondary pollution. CN105779789A discloses a wet method for separating bismuth and antimony, which uses methanesulfonic acid to selectively leach bismuth from a mixture of antimony and bismuth oxides. However, in order to prevent antimony leaching, hydrogen peroxide needs to be added to oxidize trivalent antimony to pentavalent antimony. At the same time, the leachate needs further processing after bismuth extraction.

[0004] In conclusion, there is an urgent need to develop a low-cost, clean method that can efficiently separate antimony and bismuth while reducing wastewater discharge. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a wet method for separating antimony and bismuth, which solves the problems of large wastewater volume and low separation efficiency in traditional hydrolysis separation of antimony and bismuth. At the same time, the leaching agent can be recycled after antimony is enriched by precipitation.

[0006] To achieve this objective, the present invention adopts the following technical solution: This invention provides a method for wet separation of antimony and bismuth, the method comprising the following steps: (1) The antimony-bismuth mixture was subjected to a first leaching treatment with a tartaric acid-based leaching agent, and after solid-liquid separation, antimony-rich liquid and bismuth-rich material were obtained. (2) The acid source and the antimony-rich solution obtained in step (1) are subjected to a second leaching treatment. After solid-liquid separation, antimony-precipitated liquid and antimony-rich material are obtained. The obtained antimony-precipitated liquid is reused in the first leaching treatment in step (1).

[0007] The wet separation method for antimony and bismuth provided by this invention is based on the fact that trivalent and pentavalent antimony compounds are readily soluble in tartaric acid solutions to form complex anions [(SbO)C4H4O6]. - Or [(SbO2)C4H4O6] - Since trivalent bismuth compounds are unstable, a one-step leaching process using tartaric acid-based leaching agents is employed to effectively separate the antimony and bismuth mixture. H₂ is introduced into the antimony-rich solution. + The ions can be precipitated and separated again to separate antimony, while the leaching agent is regenerated, which greatly reduces reagent costs and avoids the discharge of organic wastewater.

[0008] Preferably, the antimony compound in the antimony-bismuth mixture in step (1) is in the form of at least one of Sb2O3, SbOCl, SbONO3, (SbO)2SO4, Sb2O5, SbO2Cl or Sb4O5Cl2.

[0009] Preferably, the bismuth compound in the antimony-bismuth mixture in step (1) is in the form of at least one of Bi2O3, BiOCl, BiONO3 or (BiO)2SO4.

[0010] It should be noted that the present invention does not specifically limit the content of antimony and bismuth in the antimony-bismuth mixture described in step (1). It is well known in the art that in antimony-bismuth mixtures, the greater the difference in the content of antimony and bismuth, the easier it is to separate them; the closer the contents are, the more difficult it is to separate them. However, in the present invention, even if the antimony and bismuth contents of the antimony-bismuth mixture are similar, for example, the antimony content is 41.8% and the bismuth content is 44.9%, the antimony and bismuth can still be effectively separated, with an antimony leaching rate of up to 97.52% and a bismuth-antimony separation coefficient of up to 3709.

[0011] Preferably, the temperature of the first leaching treatment in step (1) is 30-100℃, for example, it can be 30℃, 50℃, 60℃, 80℃ or 100℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0012] Preferably, the first leaching treatment time in step (1) is 0.5-4h, for example, it can be 0.5h, 1h, 2h, 3h or 4h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] Preferably, the solid-liquid ratio of the first leaching treatment in step (1) is 1:(3-10), for example, it can be 1:3, 1:5, 1:6, 1:8 or 1:10, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] The solid-liquid ratio mentioned in this invention refers to the mass ratio of solid material to liquid material.

[0015] Preferably, the tartaric acid-based leaching agent in step (1) is [C4H4O6]. 2- The amount of Sb added should be in a molar ratio of (1-2):1, such as 1:1, 1.2:1, 1.5:1, 1.8:1 or 2:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] It should be noted that the tartaric acid-based extractant in step (1) of this invention is added in the form of an aqueous solution. The amount of solvent water can be adjusted according to the actual application scenario, as long as it can completely dissolve the tartaric acid-based extractant. This invention does not impose specific limitations on the amount of solvent water.

[0017] Preferably, the tartaric acid-based extractant in step (1) includes at least one of tartaric acid, sodium hydrogen tartrate, potassium hydrogen tartrate, potassium tartrate, or sodium tartrate.

[0018] Preferably, the acid source in step (2) is determined according to the H+ content in the solution. + Add at concentrations ≤ 1 mol / L, such as 1 mol / L, 0.8 mol / L, 0.5 mol / L, 0.3 mol / L, or 0.1 mol / L, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] Preferably, the acid source in step (2) includes at least one of hydrochloric acid, sulfuric acid, or nitric acid.

[0020] Preferably, the anion of the acid source in step (2) is consistent with the anion contained in the antimony compound in the antimony-bismuth mixture.

[0021] Preferably, the temperature of the second leaching treatment in step (2) is 25-100°C, for example, it can be 25°C, 30°C, 50°C, 80°C or 100°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the second leaching treatment time in step (2) is 0.5-4h, for example, it can be 0.5h, 1h, 2h, 3h or 4h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] Preferably, the antimony compound in the antimony-rich material in step (2) includes at least one of H3SbO3, SbOCl, SbONO3, (SbO)2SO4, H3SbO4, SbO2Cl or Sb4O5Cl2.

[0024] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0025] Compared with the prior art, the present invention has the following beneficial effects: The wet separation method for antimony and bismuth provided by this invention is based on the fact that trivalent and pentavalent antimony compounds are readily soluble in tartaric acid solutions to form complex anions [(SbO)C4H4O6]. - Or [(SbO2)C4H4O6] - However, trivalent bismuth compounds are unstable. A one-step leaching process using tartaric acid-based leaching agents on the antimony-bismuth mixture achieves effective separation of bismuth and antimony, with an antimony leaching rate reaching 97.52% and a bismuth-antimony separation coefficient of 3709. The antimony-rich solution is then infused with H₂. + The ions can be precipitated and separated again to separate antimony, while the leaching agent is regenerated, which greatly reduces reagent costs and avoids the discharge of organic wastewater. Detailed Implementation

[0026] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0027] Example 1 This embodiment provides a method for wet separation of antimony and bismuth, the method comprising the following steps: (1) Prepare the tartaric acid solution according to [C4H4O6] 2- An amount of Sb with a molar ratio of 1.5:1 was added to the antimony-bismuth mixture, and a first leaching treatment was carried out at 50°C for 2 hours with a solid-liquid ratio of 1:5. After filtration, antimony-rich liquid and bismuth-rich material were obtained. The antimony-bismuth mixture contained 41.8 wt% antimony and 44.9 wt% bismuth. The antimony compound was in the form of SbOCl, and the bismuth compound was in the form of Bi2O3.

[0028] (2) Dissolve hydrochloric acid according to the H+ in the solution. + A concentration of 0.6 mol / L was added to the antimony-rich solution obtained in step (1), and a second leaching treatment was carried out at 50°C for 2 hours. After filtration, antimony-precipitated liquid and antimony-rich material were obtained. The antimony compound in the antimony-rich material was in the form of SbOCl. The obtained antimony-precipitated liquid was reused in the first leaching treatment in step (1).

[0029] Example 2 This embodiment provides a method for wet separation of antimony and bismuth, the method comprising the following steps: (1) Prepare the sodium tartrate solution according to [C4H4O6] 2- An antimony-bismuth mixture with a Sb molar ratio of 1:1 was added to the mixture, and a first leaching treatment was performed at 30°C for 4 hours with a solid-liquid ratio of 1:3. After filtration, antimony-rich liquid and bismuth-rich material were obtained. The antimony-bismuth mixture contained 21.1 wt% antimony and 56.2 wt% bismuth. The antimony compound was in the form of SbONO3, and the bismuth compound was in the form of Bi2O3.

[0030] (2) Dissolve nitric acid according to the H+ in the solution. + A concentration of 1 mol / L was added to the antimony-rich solution obtained in step (1), and a second leaching treatment was carried out at 25°C for 4 hours. After filtration, antimony-precipitated liquid and antimony-rich material were obtained. The antimony compound in the antimony-rich material was in the form of H3SbO3. The obtained antimony-precipitated liquid was reused in the first leaching treatment in step (1).

[0031] Example 3 This embodiment provides a method for wet separation of antimony and bismuth, the method comprising the following steps: (1) Prepare the potassium tartrate solution according to [C4H4O6] 2- An antimony-bismuth mixture with a Sb molar ratio of 2:1 was added to the mixture, and a first leaching treatment was performed at 100°C for 0.5 h with a solid-liquid ratio of 1:10. After filtration, antimony-rich liquid and bismuth-rich material were obtained. The antimony-bismuth mixture contained 19.7 wt% antimony and 53.6 wt% bismuth. The antimony compound was in the form of (SbO)₂SO₄, and the bismuth compound was in the form of (BiO)₂SO₄.

[0032] (2) Dissolve sulfuric acid according to the H+ in the solution. + A concentration of 0.15 mol / L was added to the antimony-rich solution obtained in step (1), and a second leaching treatment was carried out at 100°C for 0.5 h. After filtration, antimony-precipitated liquid and antimony-rich material were obtained. The antimony compound in the antimony-rich material was in the form of H3SbO3. The obtained antimony-precipitated liquid was reused in the first leaching treatment in step (1).

[0033] Example 4 This embodiment provides a wet separation method for antimony and bismuth, which differs from Embodiment 1 in that the tartaric acid solution in step (1) is adjusted to conform to [C4H4O6]. 2- The amount of Sb added was 0.5:1, and all other aspects were the same as in Example 1.

[0034] Example 5 This embodiment provides a wet separation method for antimony and bismuth, which differs from Embodiment 1 in that the tartaric acid solution in step (1) is adjusted to conform to [C4H4O6]. 2- The amount of Sb added was 3:1, and the rest was the same as in Example 1.

[0035] Example 6 This embodiment provides a wet method for separating antimony and bismuth. The difference from Embodiment 1 is that the temperature of the first leaching treatment in step (1) and the second leaching treatment in step (2) are both adjusted to 20°C. The rest are the same as in Embodiment 1.

[0036] Example 7 This embodiment provides a wet method for separating antimony and bismuth. The difference from Embodiment 1 is that the temperature of the first leaching treatment in step (1) and the second leaching treatment in step (2) are both adjusted to 110°C. The rest are the same as in Embodiment 1.

[0037] Example 8 This embodiment provides a wet separation method for antimony and bismuth, which differs from Embodiment 1 in that the hydrochloric acid in step (2) is adjusted according to the H+ concentration in the solution. + The dosage was 1.5 mol / L, and everything else was the same as in Example 1.

[0038] Comparative Example 1 This comparative example provides a wet separation method for antimony and bismuth. The difference from Example 1 is that the tartaric acid solution of equal concentration mentioned in step (1) is replaced with a methanesulfonic acid solution, and 10% of the total mass of the antimony and bismuth mixture is added in the first leaching treatment. The rest are the same as in Example 1.

[0039] Antimony-rich solutions were obtained using the wet separation methods for antimony and bismuth provided in Examples 1-8 and Comparative Example 1. The antimony and bismuth content in the solutions was detected using inductively coupled plasma optical emission spectrometry (ICP-OES). The leaching rates of antimony and bismuth were calculated using the formula: Leaching rate = (Ion concentration in leachate × Leachate volume) / Total metal content in raw material × 100%. The results are shown in Table 1. The antimony-bismuth separation coefficient β... Sb / Bi =D Sb / D Bi D = E / (1-E), where E is the metal leaching rate. The antimony-bismuth separation coefficient was calculated, and the results are shown in Table 1. The antimony precipitation rate was calculated according to the formula: antimony content in precipitate / (antimony ion concentration in leachate × leachate volume) × 100%, and the results are shown in Table 1.

[0040] Table 1 As can be seen from Table 1, the wet separation method for antimony and bismuth provided by the present invention can achieve effective separation of antimony and bismuth and obtain a high antimony leaching rate.

[0041] A comparison of Examples 1 with Examples 4 and 5 shows that insufficient tartaric acid solution leads to incomplete antimony leaching, while excessive tartaric acid solution leads to an increased bismuth leaching rate. A comparison of Examples 1 with Examples 6 and 7 shows that excessively low leaching temperatures result in a decreased antimony leaching rate, while excessively high temperatures result in an increased bismuth leaching rate. A comparison of Examples 1 with Example 8 shows that excessive acid source content leads to a decreased antimony precipitation rate.

[0042] As can be seen from the comparison between Example 1 and Comparative Example 1, when using methanesulfonic acid solution to leach the antimony-bismuth mixture, hydrogen peroxide needs to be added to oxidize trivalent antimony to pentavalent antimony. In addition, the bismuth extracted from the leachate needs further processing, making the process relatively complicated.

[0043] In summary, the wet separation method for antimony and bismuth provided by this invention is based on the fact that trivalent and pentavalent antimony compounds are readily soluble in tartaric acid solutions to form complex anions [(SbO)C4H4O6]. - Or [(SbO2)C4H4O6] - However, trivalent bismuth compounds are unstable. A one-step leaching process using tartaric acid-based leaching agents on the antimony-bismuth mixture achieves effective separation of bismuth and antimony, with an antimony leaching rate reaching 97.52% and a bismuth-antimony separation coefficient of 3709. The antimony-rich solution is then infused with H₂. + The ions can be precipitated and separated again to separate antimony, while the leaching agent is regenerated, which greatly reduces reagent costs and avoids the discharge of organic wastewater.

[0044] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for wet separation of antimony and bismuth, characterized in that, The method includes the following steps: (1) The antimony-bismuth mixture was subjected to a first leaching treatment with a tartaric acid-based leaching agent, and after solid-liquid separation, antimony-rich liquid and bismuth-rich material were obtained. (2) The acid source and the antimony-rich solution obtained in step (1) are subjected to a second leaching treatment. After solid-liquid separation, antimony-precipitated liquid and antimony-rich material are obtained. The obtained antimony-precipitated liquid is reused in the first leaching treatment in step (1).

2. The method according to claim 1, characterized in that, The form of antimony compound in the antimony-bismuth mixture in step (1) includes at least one of Sb2O3, SbOCl, SbONO3, (SbO)2SO4, Sb2O5, SbO2Cl or Sb4O5Cl2; Preferably, the bismuth compound in the antimony-bismuth mixture in step (1) is in the form of at least one of Bi2O3, BiOCl, BiONO3 or (BiO)2SO4.

3. The method according to claim 1 or 2, characterized in that, Step (1) The temperature of the first leaching treatment is 30-100℃; Preferably, the first leaching treatment in step (1) takes 0.5-4 hours.

4. The method according to any one of claims 1-3, characterized in that, Step (1) The solid-liquid ratio of the first leaching treatment is 1:(3-10).

5. The method according to any one of claims 1-4, characterized in that, In step (1), the tartaric acid-based leaching agent is prepared according to [C4H4O6]. 2- The amount of Sb added is (1-2):1 in a molar ratio of (1-2):

1.

6. The method according to any one of claims 1-5, characterized in that, The tartaric acid-based leaching agent in step (1) includes at least one of tartaric acid, sodium hydrogen tartrate, potassium hydrogen tartrate, potassium tartrate, or sodium tartrate.

7. The method according to any one of claims 1-6, characterized in that, The acid source in step (2) is determined according to the H in the solution. + Add at a concentration ≤ 1 mol / L; Preferably, the acid source in step (2) includes at least one of hydrochloric acid, sulfuric acid, or nitric acid.

8. The method according to any one of claims 1-7, characterized in that, In step (2), the anions of the acid source are consistent with the anions contained in the antimony compound in the antimony-bismuth mixture.

9. The method according to any one of claims 1-8, characterized in that, In step (2), the temperature of the second leaching treatment is 25-100℃; Preferably, the second leaching treatment in step (2) takes 0.5-4 hours.

10. The method according to any one of claims 1-9, characterized in that, The form of antimony compound in the antimony-rich material in step (2) includes at least one of H3SbO3, SbOCl, SbONO3, (SbO)2SO4, H3SbO4, SbO2Cl or Sb4O5Cl2.

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