A process for the hydrometallurgical extraction of antimony from antimony sulfide

Abstract

The application relates to the field of hydrometallurgy and specifically discloses a process method for hydrometallurgical extraction of antimony from antimony sulfide. The process method for hydrometallurgical extraction of antimony from antimony sulfide comprises the following steps: S1, mixing antimony sulfide-containing material with a tetrafluoroborate ionic liquid, adding water for slurry treatment, and obtaining a slurry; S2, adding the slurry into a leaching tank provided with a bidirectional reaction structure, and performing leaching treatment under a nitrogen protective atmosphere; the lower part of the leaching tank is a slurry phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added into the slurry phase; S3, eluting the organic phase after the leaching treatment, filtering, and obtaining an antimony-containing solution; S4, sending the antimony-containing solution into an electrolytic cell for electro-deposition treatment, and collecting antimony. The method can improve the leaching efficiency of antimony, and is favorable for improving the recovery rate of antimony.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hydrometallurgy, more particularly, it relates to a process for hydrometallurgical extraction of antimony from antimony sulfide. BACKGROUND

[0002] As an important non-ferrous metal, antimony has a wide and key application in many fields. In the field of flame retardants, the compounds of antimony can significantly improve the flame retardant performance of materials, and are widely used in plastic, rubber, textile and other industries, effectively reducing the risk of fire and protecting people's life and property safety. In the electronics industry, antimony and its alloys are used to manufacture semiconductor devices, infrared detectors and other devices due to their unique physical properties, playing an irreplaceable role in promoting the development of electronic information technology. Since the industrial revolution, with the rapid development of manufacturing industry, the demand for antimony has continued to rise, and its production and application range have also been expanding.

[0003] In the prior art, the processes for extracting antimony from antimony sulfide mainly include pyrometallurgy and hydrometallurgy. Among them, the related technology such as the patent application file with the publication number CN104831315A discloses a new process for recovering antimony from antimony-containing gold concentrate, which includes steps of slurry, leaching, pressure filtration washing, electrodeposition, waste liquid treatment, etc. The leaching step includes: pumping the slurry after slurry into the closed stirred leaching tank in the leaching workshop, adding the cathode liquid returned from the electrodeposition workshop to adjust the concentration of the slurry to 50wt%, and then entering the leaching tank in sequence for leaching, adding Na2S and NaOH solution into the leaching tank, keeping the concentration of Na2S in the slurry at 50g / L, and the concentration of NaOH at 20g / L.

[0004] The above-mentioned hydrometallurgical process has certain advantages in environmental protection, but due to the complex composition of antimony gold concentrate, part of the antimony sulfide may be wrapped by other impurities or form a complex mineral structure, making it difficult for sodium sulfide and sodium hydroxide to fully contact and react with it, which limits the leaching efficiency and further affects the recovery rate of antimony. And because sodium sulfide is easily oxidized into polysulfide and thiosulfate which have leaching effect on gold, part of the gold is dissolved into the antimony leaching solution, which increases the cost of subsequent separation and further affects the recovery rate of antimony. Therefore, how to improve the recovery rate of antimony under the premise of environmental protection has become a technical problem to be solved. SUMMARY

[0005] In order to improve the recovery rate of antimony, the present application provides a process for hydrometallurgical extraction of antimony from antimony sulfide.

[0006] The process for hydrometallurgical extraction of antimony from antimony sulfide provided by the present application adopts the following technical scheme:

[0007] A process for hydrometallurgical extraction of antimony from antimony sulfide, comprising the following steps:

[0008] S1. Mixing the antimony sulfide-containing material with a tetrafluoroborate ionic liquid, and adding water for slurrying to obtain a slurry;

[0009] S2. Adding the slurry to a leaching tank provided with a two-way reaction structure, and performing a leaching treatment under a nitrogen atmosphere, wherein the upper portion of the leaching tank is an organic phase composed of N-laurylacetamide and kerosene solution; the lower portion of the leaching tank is a slurry phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres, and a catalyst are added to the slurry phase;

[0010] S3, eluting the organic phase after the leaching treatment, collecting the eluate, and then filtering the eluate to obtain an antimony-containing solution;

[0011] S4. The antimony-containing solution is fed into an electrolytic cell for electrolytic treatment, and the antimony on the cathode is collected using a mechanical scraper device.

[0012] By adopting the above technical solution, in step S1, the tetrafluoroborate ionic liquid has a unique anion-cation structure. Its cation portion can interact with the sulfur ions on the surface of antimony sulfide, while the anion portion can bind to the antimony ions, thereby weakening the strength of the antimony-sulfur bond in the antimony sulfide and making the antimony sulfide more easily dissolve in the ore pulp. During the wet extraction of antimony, the valence state of the antimony ion is prone to change, and the tetrafluoroborate ionic liquid can play a role in stabilizing the valence state of the antimony ion. Certain components in the ionic liquid can form stable complexes with the antimony ion, limiting the redox reaction of the antimony ion and maintaining it in a stable valence state that is conducive to subsequent extraction.

[0013] During the S2 leaching process, nitrogen is introduced as an inert gas for protection. By exhausting air from the reaction system, the contact between oxygen and the leachate is reduced, helping to maintain the leachate's stability, increase its peak oxidation potential, and reduce the possibility of sodium sulfide being oxidized. This allows gold to dissolve into the antimony leachate, subsequently improving antimony recovery. The bidirectional reaction structure promotes material exchange between the slurry phase and the organic phase; the organic phase, composed of N-dodecylacetamide and kerosene solution, extracts antimony ions and achieves a preliminary separation of antimony from impurities.

[0014] The surface of the modified chitosan microspheres is rich in functional groups that interact with sodium sulfide and antimony sulfide. They adsorb sodium sulfide and concentrate it on the microsphere surface, making it more evenly distributed in the slurry. This increases the contact area between sodium sulfide and antimony sulfide, promoting the dissolution of antimony sulfide and improving leaching efficiency. The modified groups (dithiocarbamate groups) on the modified chitosan microspheres have a strong complexing ability for gold, securing it to the microsphere surface and preventing it from entering the antimony leachate. This reduces subsequent separation costs and antimony loss, further improving antimony recovery.

[0015] Optionally, the modified chitosan microspheres are prepared by the following method:

[0016] A, the chitosan microspheres are added to a sodium hydroxide solution, stirred at room temperature for 20-30 min, then carbon disulfide and ethylenediamine are added, and stirred at room temperature for 3-4 h to obtain a product mixture;

[0017] B, the product mixture is filtered, the solid phase is washed with deionized water until neutral, then dried at 40-60℃ to constant weight to obtain the modified chitosan microspheres.

[0018] By adopting the above technical solution, the chitosan microspheres swell in the sodium hydroxide solution, carbon disulfide and ethylenediamine react with the chitosan microspheres to introduce dithiocarbamate groups and other active groups, so that the surface of the microspheres has abundant functional groups, thereby having the ability to adsorb sodium sulfide and complex gold ions. Ethylenediamine contains two amino groups, which can increase the active sites on the surface of the microspheres, thereby enhancing the modification efficiency and complexing ability of carbon disulfide on the chitosan microspheres. The above method is simple and feasible, and can prepare modified chitosan microspheres with dithiocarbamate groups, which is conducive to improving the leaching efficiency of antimony and inhibiting the dissolution of gold into the antimony leaching solution, and thus is conducive to improving the recovery rate of antimony.

[0019] Optionally, the mass concentration of the sodium hydroxide solution in step A is 5%-10%; the mass ratio of chitosan microspheres to sodium hydroxide solution is 1:(40-50).

[0020] Optionally, the mass ratio of chitosan microspheres to carbon disulfide in step A is 1:(3-5); the mass ratio of chitosan microspheres to ethylenediamine is 1:(2-2.5).

[0021] By adopting the above technical solution, the mass ratio of carbon disulfide, ethylenediamine and chitosan microspheres is defined, so that the modification reaction can proceed as expected, and the modified chitosan microspheres have sufficient active groups to achieve adsorption of sodium sulfide and complexation of gold. The appropriate mass ratio can control the degree of modification reaction and the structure of the product. Carbon disulfide is used to introduce dithiocarbamate groups, and ethylenediamine can increase the active sites on the surface of the microspheres. By accurately controlling the ratio of them to chitosan microspheres, the performance of the modified chitosan microspheres can be optimized.

[0022] Optionally, the mass ratio of the antimony sulfide-containing material in S1 to the tetrafluoroborate ionic liquid is 1:(0.3-0.5); the tetrafluoroborate ionic liquid is preferably 1-ethyl-3-methylimidazolium tetrafluoroborate.

[0023] By adopting this technical solution, the appropriate mass ratio ensures sufficient contact between the ionic liquid and the antimony sulfide-containing material, allowing the anions and cations of the ionic liquid to effectively interact with the antimony sulfide and antimony ions. 1-Ethyl-3-methylimidazolium tetrafluoroborate has excellent solubility and chemical stability, enabling better activation of antimony sulfide and stabilization of antimony ions.

[0024] Optionally, during the nitrogen protection in S2, the nitrogen flow rate is 0.5-1.5 L / min, and the pressure range in the leaching tank is 8-10 kPa.

[0025] By adopting this technical solution, an appropriate nitrogen inlet flow rate can promptly expel air from the reaction system, maintaining a slightly positive pressure to prevent external air from entering the leaching tank. This limited pressure range ensures the sealing and stability of the reaction system, providing an optimal oxygen-free environment for the leaching reaction and preventing oxidation of the sodium sulfide.

[0026] Optionally, in S2, the amount of N-dodecylacetamide added is 0.5%-1.5% of the mass of the ore pulp; the amount of kerosene solution added is 3%-5% of the mass of the ore pulp; the amount of sodium sulfide added is 8%-12% of the mass of the ore pulp; the amount of sodium hydroxide added is 2%-4% of the mass of the ore pulp; the amount of modified chitosan microspheres added is 0.2%-0.5% of the mass of the ore pulp; and the amount of catalyst added is 0.05%-0.2% of the mass of the ore pulp.

[0027] Optionally, the catalyst in S2 is any one of copper sulfate and ferrous sulfate.

[0028] By adopting the above technical solution, the metal ions in copper sulfate and ferrous sulfate can act as catalysts, participate in the electron transfer process of the reaction, reduce the activation energy of the reaction, thereby accelerating the reaction rate of antimony sulfide with reagents such as sodium sulfide and sodium hydroxide, and allowing more antimony to be leached in a shorter time.

[0029] Optionally, the elution process in S3 includes the following steps:

[0030] Add a hydrochloric acid solution with a concentration of 1.5-2.5 mol / L to the organic phase after the leaching treatment, with the volume ratio of the hydrochloric acid solution to the organic phase being 1:(2-3), stir and elute at 30-40°C for 30-45 minutes, then let it stand to separate the layers, and collect the lower aqueous phase as the eluent.

[0031] Optionally, during the electrowinning treatment in S4, the lead-antimony alloy is used as the anode and the stainless steel is used as the cathode, the cell voltage is controlled to be 1.8-2.2V, and the current density is 150-200A / m 2 .

[0032] In summary, this application has the following beneficial effects:

[0033] 1. Modified chitosan microspheres and catalysts are used in this application. Since the surface of the modified chitosan microspheres is rich in functional groups, they can adsorb sodium sulfide and distribute it more evenly in the slurry, increasing the contact area between sodium sulfide and antimony sulfide and promoting the dissolution of antimony sulfide. The modified groups (dithiocarbamate groups) on the microspheres have a strong complexing ability for gold, which can fix gold on the surface of the microspheres and prevent it from entering the antimony leachate. The metal ions in the catalysts (copper sulfate and ferrous sulfate) can participate in the electron transfer process of the reaction, reducing the activation energy of the reaction and accelerating the reaction rate of antimony sulfide with reagents such as sodium sulfide and sodium hydroxide. Therefore, the leaching efficiency is improved, the subsequent separation cost and antimony loss are reduced, and thus the recovery rate of antimony is improved.

[0034] 2. The method of the present application, by introducing nitrogen protection during the S2 leaching process and controlling the nitrogen flow rate to 0.5-1.5 L / min, maintains a slightly positive pressure in the leaching tank. This can expel air from the reaction system, reduce the contact between oxidizing gases such as oxygen and the leachate, maintain the stability of the leachate, and increase its peak oxidation potential. This reduces the possibility of sodium sulfide being oxidized, prevents gold from dissolving into the antimony leachate, provides a good oxygen-free environment for the leaching reaction, and is conducive to improving the subsequent antimony recovery rate.

[0035] 3. The tetrafluoroborate ionic liquid used in this application has a unique anion-cation structure. The cation portion of the 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid can interact with the sulfur ions on the surface of antimony sulfide, while the anion portion can bind to the antimony ions, thereby weakening the antimony-sulfur bond in the antimony sulfide. Furthermore, certain components in the ionic liquid can form stable complexes with the antimony ions, limiting the redox reactions of the antimony ions. Therefore, it can make antimony sulfide more easily dissolve in the ore pulp, stabilize the valence of the antimony ions, and keep them in a stable valence state that is conducive to subsequent extraction, thereby improving the antimony recovery rate. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to the embodiments.

[0037] Preparation example of modified chitosan microspheres

[0038] Preparation Example 1

[0039] Modified chitosan microspheres are prepared by the following method:

[0040] A. Add 1 kg of chitosan microspheres to 40 kg of 5% sodium hydroxide solution, stir at room temperature for 20 min, then add 3 kg of carbon disulfide and 2 kg of ethylenediamine, stir and react at room temperature for 3 h to obtain a product mixture;

[0041] B. Filter the product mixture, take the solid phase, wash it with deionized water until it is neutral, and then dry it at 40° C. to constant weight to obtain modified chitosan microspheres.

[0042] Preparation Example 2

[0043] Modified chitosan microspheres are prepared by the following method:

[0044] A. Add 1 kg of chitosan microspheres to 45 kg of 8% sodium hydroxide solution, stir at room temperature for 25 min, then add 4 kg of carbon disulfide and 2.2 kg of ethylenediamine, stir at room temperature for 3.5 h to obtain a product mixture;

[0045] B. Filter the product mixture, take the solid phase, wash it with deionized water until it is neutral, and then dry it at 50° C. to constant weight to obtain modified chitosan microspheres.

[0046] Preparation Example 3

[0047] Modified chitosan microspheres are prepared by the following method:

[0048] A. Add 1 kg of chitosan microspheres to 50 kg of 10% sodium hydroxide solution, stir at room temperature for 30 min, then add 5 kg of carbon disulfide and 2.5 kg of ethylenediamine, stir and react at room temperature for 4 h to obtain a product mixture;

[0049] B. Filter the product mixture, take the solid phase, wash it with deionized water until it is neutral, and then dry it at 60° C. to constant weight to obtain modified chitosan microspheres.

[0050] Preparation Example 4

[0051] The modified chitosan microspheres are different from those prepared in Preparation Example 1 in that no ethylenediamine is added in this preparation example.

[0052] Preparation Example 5

[0053] The modified chitosan microspheres are different from those in Preparation Example 1 in that the amount of ethylenediamine added in this Preparation Example is 4 kg.

[0054] Example

[0055] The antimony sulfide-containing material used in the examples of the present application is antimony-gold concentrate from the Xiangxi gold mine in Hunan Province. The composition of the antimony-gold concentrate is shown in Table 1.

[0056] Table 1 Main components of antimony-gold concentrate

[0057]

[0058] It can be seen from Table 1 that the main chemical components of this antimony-gold concentrate are iron, antimony and sulfur, but the gold grade is also very high.

[0059] Example 1

[0060] A process for wet extraction of antimony from antimony sulfide comprises the following steps:

[0061] S1. After mixing 10 kg of antimony gold concentrate and 3 kg of 1-ethyl-3-methylimidazolium tetrafluoroborate, water was added to slurry, and the slurry concentration was controlled to be 60 wt % to obtain ore pulp.

[0062] S2, the pulp is added to a leaching tank provided with a two-way reaction structure, and leaching treatment is carried out under a nitrogen atmosphere. The upper part of the leaching tank is an organic phase, which is composed of N-lauryl acetamide and kerosene solution; the lower part of the leaching tank is a pulp phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added to the pulp phase. The amount of material added in this step is shown in Table 2. In this step, the modified chitosan microspheres are selected from the modified chitosan microspheres obtained in Preparation Example 1, and ferrous sulfate is selected as the catalyst. The nitrogen flow rate is 0.5L / min, and the pressure in the leaching tank is 8kPa.

[0063] S3. Add a 1.5 mol / L hydrochloric acid solution to the organic phase after the leaching treatment, with a volume ratio of the hydrochloric acid solution to the organic phase of 1:2, stir and elute at 30°C for 30 minutes, then let it stand to separate the layers, collect the lower aqueous phase as the eluate, and then filter the eluate to obtain an antimony-containing solution.

[0064] S4. The antimony-containing solution is fed into the electrolytic cell for electrolytic treatment. During the electrolytic treatment, the lead-antimony alloy is used as the anode and the stainless steel is used as the cathode. The cell voltage is controlled to be 1.8V and the current density is 150A / m 2 , a mechanical scraper device is used to collect the antimony on the cathode.

[0065] Example 2

[0066] A process for wet extraction of antimony from antimony sulfide comprises the following steps:

[0067] S1. After mixing 10 kg of antimony gold concentrate and 4 kg of 1-ethyl-3-methylimidazolium tetrafluoroborate, water was added to slurry, and the slurry concentration was controlled to be 60 wt % to obtain ore pulp.

[0068] S2. Add the slurry to a leaching tank equipped with a two-way reaction structure and perform leaching under a nitrogen atmosphere. The upper portion of the leaching tank contains an organic phase composed of N-lauryl acetamide and a kerosene solution; the lower portion of the leaching tank contains a slurry phase. During leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres, and a catalyst are added to the slurry phase. The amounts of material added in this step are shown in Table 2. In this step, the modified chitosan microspheres are selected from those obtained in Preparation Example 2, and copper sulfate is selected as the catalyst. The nitrogen flow rate is 1.0 L / min, and the pressure in the leaching tank is 9 kPa.

[0069] S3. Add a 2.0 mol / L hydrochloric acid solution to the organic phase after the leaching treatment, with a volume ratio of the hydrochloric acid solution to the organic phase of 1:2.5, stir and elute at 35°C for 38 minutes, then let it stand to separate, collect the lower aqueous phase as the eluent, and then filter the eluent to obtain an antimony-containing solution.

[0070] S4. The antimony-containing solution is fed into the electrolytic cell for electrolytic treatment. During the electrolytic treatment, the lead-antimony alloy is used as the anode and the stainless steel is used as the cathode. The cell voltage is controlled to be 2.0V and the current density is 180A / m 2 , a mechanical scraper device is used to collect the antimony on the cathode.

[0071] Example 3

[0072] A process for wet extraction of antimony from antimony sulfide comprises the following steps:

[0073] S1. After mixing 10 kg of antimony gold concentrate and 5 kg of 1-ethyl-3-methylimidazolium tetrafluoroborate, water was added to slurry, and the slurry concentration was controlled to be 60 wt % to obtain ore pulp.

[0074] S2. Add the slurry to a leaching tank equipped with a two-way reaction structure and perform leaching under a nitrogen atmosphere. The upper portion of the leaching tank contains an organic phase composed of N-lauryl acetamide and a kerosene solution; the lower portion of the leaching tank contains a slurry phase. During leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres, and a catalyst are added to the slurry phase. The amounts of material added in this step are shown in Table 2. In this step, the modified chitosan microspheres are selected from those obtained in Preparation Example 3, and copper sulfate is selected as the catalyst. The nitrogen flow rate is 1.5 L / min, and the pressure in the leaching tank is 10 kPa.

[0075] S3. Add a 2.5 mol / L hydrochloric acid solution to the organic phase after the leaching treatment, with a volume ratio of the hydrochloric acid solution to the organic phase of 1:3, stir and elute at 40°C for 45 minutes, then let it stand to separate the layers, collect the lower aqueous phase as the eluate, and then filter the eluate to obtain an antimony-containing solution.

[0076] S4, the antimony-containing solution is sent into an electrolytic cell for electro-deposition treatment, during the electro-deposition treatment, a lead-antimony alloy is used as an anode, a stainless steel is used as a cathode, a cell voltage is controlled to be 2.2 V, and a current density is controlled to be 200 A / m 2 The antimony on the cathode is collected by using a mechanical scraper device.

[0077] Table 2: Material usage in S2 of Examples 1-3

[0078] Material (kg) Example 1 Example 2 Example 3 slurry 16.67 16.67 16.67 N-dodecyl acetamide 0.083 0.167 0.25 Kerosene solution 0.5 0.667 0.833 Sodium sulfide 1.333 1.667 2 Sodium hydroxide 0.333 0.5 0.667 Modified chitosan microspheres 0.033 0.058 0.083 catalyst 0.0083 0.021 0.033

[0079] Example 4

[0080] A process method for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that the modified chitosan microspheres in S2 of the present example are prepared by using the modified chitosan microspheres prepared in Preparation Example 4.

[0081] Example 5

[0082] A process method for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that the modified chitosan microspheres in S2 of the present example are prepared by using the modified chitosan microspheres prepared in Preparation Example 5.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] A process method for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that the 1-ethyl-3-methylimidazole tetrafluoroborate salt is not added in S1 of the present comparative example, and the amount is supplemented with water.

[0086] Comparative Example 2

[0087] A process method for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that the step S2 in the present comparative example is not performed under nitrogen protection.

[0088] Comparative Example 3

[0089] A process method for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that the same amount of chitosan microspheres is used instead of modified chitosan microspheres in S2 of the present comparative example.

[0090] Comparative Example 4

[0091] A process method for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that no catalyst is added in S2 of the present comparative example.

[0092] Performance detection test

[0093] According to the composition table of antimony gold concentrate in Table 1, the content of antimony (Sb) in the antimony gold concentrate is 27.03%. Therefore, the theoretical mass of antimony in each kg of antimony gold concentrate = 1 kg × 27.03% = 0.2703 kg, or 270.3 g.

[0094] The antimony extracted from the above Examples 1-5 and Comparative Examples 1-4 were weighed respectively, and the results are shown in Table 3 below. According to the above antimony-gold concentrate composition table and calculation process, theoretically, 2703g of metallic antimony can be extracted from 10kg of antimony-gold concentrate in this Example and the Comparative Example.

[0095] Table 3 The mass of metallic antimony extracted from Examples 1-5 and Comparative Examples 1-4

[0096] project Metal antimony mass (g) Recovery rate (%) Example 1 2603 96.3 Example 2 2600 96.2 Example 3 2611 96.6 Example 4 2546 94.2 Example 5 2549 94.3 Comparative Example 1 2462 91.1 Comparative Example 2 2368 87.6 Comparative Example 3 2306 85.3 Comparative Example 4 2327 86.1

[0097] The antimony recovery rates in Examples 1-3 ranged from 96.2% to 96.6%, representing a high level. Examples 1-3 fully utilize the process described in this application. The tetrafluoroborate ionic liquid weakens the antimony-sulfur bond in antimony sulfide, stabilizing the antimony ion valence; nitrogen protection reduces oxidation of sodium sulfide, preventing gold from dissolving into the leachate; modified chitosan microspheres evenly distribute sodium sulfide, increasing its contact area with antimony sulfide and complexing gold ions to prevent it from entering the leachate; and the catalyst accelerates the reaction rate. These factors work synergistically to promote the dissolution and leaching of antimony sulfide, reduce impurity interference, and improve antimony recovery.

[0098] The antimony recovery rates in Examples 4 and 5 were 94.2% and 94.3%, respectively, slightly lower than those in Examples 1-3. This was primarily due to differences in the preparation conditions for the modified chitosan microspheres; Example 4 omitted ethylenediamine, while Example 5 added different amounts of ethylenediamine. This may have affected the number or activity of functional groups on the surface of the modified chitosan microspheres, slightly reducing their sodium sulfide adsorption and gold complexing abilities. This, in turn, affected the leaching and separation of antimony, resulting in a slightly lower recovery rate. However, this was still higher than that of Comparative Examples 1-4, demonstrating the overall stability of the process.

[0099] The recovery rate of Comparative Example 1 was 91.1%. In this comparative example, no tetrafluoroborate ionic liquid was added to S1. The lack of an ionic liquid to weaken the antimony-sulfur bond in antimony sulfide made dissolution more difficult. Furthermore, the inability to stabilize the valence state of the antimony ions facilitated redox reactions, hindering subsequent extraction and resulting in a lower antimony recovery rate.

[0100] The recovery rate in Comparative Example 2 was 87.6%, as step S2 was not performed under nitrogen. Oxidizing gases such as oxygen oxidize sodium sulfide into polysulfides and thiosulfates, which dissolve gold into the antimony leachate, increasing separation costs and affecting the antimony leaching reaction, reducing the antimony recovery rate.

[0101] The recovery rate in Comparative Example 3 was 85.3%. In S2, an equal amount of chitosan microspheres was used instead of modified chitosan microspheres. Ordinary chitosan microspheres have fewer surface functional groups, making them ineffective at adsorbing and evenly distributing sodium sulfide. They also struggle to complex gold ions, reducing the efficiency of antimony sulfide dissolution and allowing gold to easily enter the leachate, significantly reducing antimony recovery.

[0102] The recovery rate of Comparative Example 4 was 86.1%, and no catalyst was added to S2. The lack of a catalyst cannot effectively reduce the activation energy of the reaction, resulting in a slower reaction rate of antimony sulfide with reagents such as sodium sulfide and sodium hydroxide, and a reduction in the amount of antimony leached in the same time, thereby reducing the antimony recovery rate. This specific embodiment is merely an explanation of the present application and is not intended to limit the present application. After reading this specification, those skilled in the art may make modifications to this embodiment as needed that do not contribute to creativity, but as long as they are within the scope of the claims of this application, they are protected by patent law.

Claims

1. A process for wet extraction of antimony from antimony sulfide, characterized in that: The steps include: S1. After mixing the antimony sulfide-containing material with a tetrafluoroborate ionic liquid, water is added for slurrying to obtain a slurry; the mass ratio of the antimony sulfide-containing material to the tetrafluoroborate ionic liquid is 1:(0.3-0.5); the tetrafluoroborate ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate; S2. Adding the slurry to a leaching tank provided with a two-way reaction structure, and performing leaching treatment under a nitrogen atmosphere, wherein the upper portion of the leaching tank is an organic phase composed of N-laurylacetamide and kerosene solution; the lower portion of the leaching tank is a slurry phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added to the slurry phase; the modified chitosan microspheres are prepared by the following method: A. Add chitosan microspheres to sodium hydroxide solution, stir at room temperature for 20-30 minutes, then add carbon disulfide and ethylenediamine, stir and react at room temperature for 3-4 hours to obtain a product mixture; B. Filter the product mixture, take the solid phase and wash it with deionized water until it is neutral, and then dry it at 40-60°C to constant weight to obtain modified chitosan microspheres; S3, eluting the organic phase after the leaching treatment, collecting the eluate, and then filtering the eluate to obtain an antimony-containing solution; S4. The antimony-containing solution is fed into an electrolytic cell for electrolytic treatment, and the antimony on the cathode is collected using a mechanical scraper device.

2. The process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: The mass concentration of the sodium hydroxide solution in step A is 5%-10%; the mass ratio of chitosan microspheres to sodium hydroxide solution is 1:(40-50).

3. The process for wet extraction of antimony from antimony sulfide according to claim 2, characterized in that: In step A, the mass ratio of the chitosan microspheres to carbon disulfide is 1:(3-5); the mass ratio of the chitosan microspheres to ethylenediamine is 1:(2-2.5).

4. The process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: During the nitrogen protection in S2, the nitrogen flow rate is 0.5-1.5 L / min, and the pressure range in the leaching tank is 8-10 kPa.

5. The process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: In S2, the amount of N-dodecyl acetamide added is 0.5%-1.5% of the mass of the ore pulp; the amount of kerosene solution added is 3%-5% of the mass of the ore pulp; the amount of sodium sulfide added is 8%-12% of the mass of the ore pulp; the amount of sodium hydroxide added is 2%-4% of the mass of the ore pulp; the amount of modified chitosan microspheres added is 0.2%-0.5% of the mass of the ore pulp; and the amount of catalyst added is 0.05%-0.2% of the mass of the ore pulp.

6. The process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: The catalyst in S2 is any one of copper sulfate and ferrous sulfate.

7. The process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: The elution process in S3 comprises the following steps: Add a hydrochloric acid solution with a concentration of 1.5-2.5 mol / L to the organic phase after the leaching treatment, with the volume ratio of the hydrochloric acid solution to the organic phase being 1:(2-3), stir and elute at 30-40°C for 30-45 minutes, then let it stand to separate the layers, and collect the lower aqueous phase as the eluent.

8. The process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: During the electrolytic treatment in S4, the lead-antimony alloy is used as the anode and the stainless steel is used as the cathode. The cell voltage is controlled to be 1.8-2.2V and the current density is 150-200A / m 2 .

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