Process method for wet extraction of antimony from antimony sulfide

Abstract

The invention relates to the field of hydrometallurgy, and particularly discloses a technological method for extracting antimony from antimony sulfide through a wet method. A process method for wet extraction of antimony from antimony sulfide comprises the following steps: S1, mixing an antimony sulfide-containing material with a tetrafluoroborate ionic liquid, and adding water for slurrying to obtain ore pulp; s2, the ore pulp is added into a leaching tank with a two-way reaction structure, and leaching treatment is conducted under the nitrogen protection atmosphere; the lower part in the leaching tank is an ore pulp phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added into an ore pulp phase; s3, the organic phase obtained after leaching treatment is completed is eluted and filtered, and an antimony-containing solution is obtained; and S4, the antimony-containing solution is fed into an electrolytic bath to be subjected to electrodeposition treatment, and antimony is collected. By means of the method, the antimony leaching efficiency can be improved, and then the antimony recovery rate can be improved.

Description

Technical Field

[0001] This application relates to the field of hydrometallurgy. More specifically, it relates to a process for wet extraction of antimony from antimony sulfide. Background Art

[0002] Antimony, as an important non-ferrous metal, has extensive and crucial applications in many fields. In the field of flame retardants, antimony compounds can significantly improve the flame retardant properties of materials and are widely used in industries such as plastics, rubber, and textiles, effectively reducing the risk of fire and safeguarding people's lives and property. In the electronics industry, antimony and its alloys, with their unique physical properties, are used to manufacture semiconductor devices, infrared detectors, etc., playing an irreplaceable role in promoting the development of electronic information technology. Since the Industrial Revolution, with the rapid development of the manufacturing industry, the demand for antimony has continued to climb, and its production and application scope have also been continuously expanding. In the prior art, the processes for extracting antimony from antimony sulfide mainly include two categories: pyrometallurgy and hydrometallurgy. Among them, related technologies such as the patent application document with the publication number CN104831315A disclose a new process for recovering antimony from antimony-containing gold concentrate, which includes steps such as pulping, leaching, pressure filtration and washing, electrowinning, and waste liquid treatment. The leaching step includes: pumping the pulped pulp to a closed stirring leaching tank in the leaching workshop, adding the cathode liquid returned from the electrowinning workshop to adjust the pulp concentration to 50 wt%, and then flowing into the leaching tank for leaching. Add Na2S and NaOH solutions to the leaching tank, and keep the Na2S concentration in the pulp at 50 g / L and the NaOH concentration at 20 g / L.

[0003] Although the above hydrometallurgy process has certain advantages in terms of environmental protection, due to the complex composition of antimony-containing gold concentrate, some antimony sulfide may be wrapped by other impurities or form complex mineral structures, making it difficult for sodium sulfide and sodium hydroxide to come into sufficient contact and reaction with it, resulting in limited leaching efficiency and thus affecting the recovery rate of antimony; and because sodium sulfide is easily oxidized into polysulfides and thiosulfates that have a leaching effect on gold, some gold dissolves into the antimony leaching solution, resulting in an increase in subsequent separation costs and further affecting the recovery rate of antimony. Therefore, how to improve the recovery rate of antimony while ensuring environmental protection has become an urgent technical problem to be solved. Summary of the Invention

[0004] In order to improve the recovery rate of antimony, this application provides a process for wet extraction of antimony from antimony sulfide.

[0005] A process for wet extraction of antimony from antimony sulfide provided by this application adopts the following technical solution: A process for wet extraction of antimony from antimony sulfide includes the following steps: S1. After mixing the antimony sulfide-containing material with the tetrafluoroborate ionic liquid, water is added for pulping to obtain a pulp. S2. The pulp is added to a leaching tank equipped with a two-way reaction structure, and leaching treatment is carried out under a nitrogen protection atmosphere. The upper part inside the leaching tank is the organic phase, which is composed of N-dodecylacetamide and kerosene solution; the lower part inside the leaching tank is the pulp phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added to the pulp phase. S3. The organic phase after the leaching treatment is eluted, the eluate is collected, and then the eluate is filtered to obtain an antimony-containing solution. S4. The antimony-containing solution is sent to an electrolytic cell for electrowinning treatment, and antimony on the cathode is collected by a mechanical scraper device.

[0006] By adopting the above technical solution, in step S1, the tetrafluoroborate ionic liquid has a unique cation-anion structure. Its cation part can interact with the sulfide ions on the surface of antimony sulfide, and the anion part can combine with antimony ions, thereby weakening the strength of the antimony-sulfur bond in antimony sulfide and making antimony sulfide more easily dissolved in the pulp. During the wet extraction of antimony, the valence state of antimony ions is prone to change, while the tetrafluoroborate ionic liquid can play a role in stabilizing the valence state of antimony ions. Some components in the ionic liquid can form stable complexes with antimony ions, restricting the redox reaction of antimony ions and keeping them in a stable valence state beneficial to subsequent extraction.

[0007] During the S2 leaching process, inert gas nitrogen protection is introduced. By exhausting the air in the reaction system, the contact between oxygen and other oxidizing gases and the leaching solution is reduced, which helps to maintain the stability of the leaching solution, increase its oxidation peak potential, and reduce the possibility of sodium sulfide being oxidized. Therefore, gold can be dissolved into the antimony leaching solution, which is beneficial to improving the subsequent recovery rate of antimony. The two-way reaction structure promotes the mass transfer between the pulp phase and the organic phase; the organic phase is composed of N-dodecylacetamide and kerosene solution, which can extract antimony ions and realize the preliminary separation of antimony and impurities.

[0008] The surface of the modified chitosan microspheres has abundant functional groups and can interact with sodium sulfide and antimony sulfide. It can adsorb sodium sulfide and enrich it on the surface of the microspheres, so that sodium sulfide is more evenly distributed in the pulp, and at the same time, the contact area between sodium sulfide and antimony sulfide is increased, thereby promoting the dissolution of antimony sulfide and improving the leaching efficiency. The modified groups (dithiocarbamate groups) on the modified chitosan microspheres have a strong complexing ability for gold, can fix gold on the surface of the microspheres, prevent them from entering the antimony leaching solution, reduce the subsequent separation cost and the loss of antimony, and thus further improve the recovery rate of antimony.

[0009] Optionally, the modified chitosan microspheres are prepared by the following method: A. Add chitosan microspheres to sodium hydroxide solution and stir at room temperature for 20 - 30 min. Then add carbon disulfide and ethylenediamine, and stir and react at room temperature for 3 - 4 h to obtain a product mixture; B. Filter the product mixture, take the solid phase, wash it with deionized water until neutral, and then dry it to constant weight at 40 - 60 °C to obtain modified chitosan microspheres.

[0010] By adopting the above technical solution, the chitosan microspheres swell in the sodium hydroxide solution, and carbon disulfide and ethylenediamine react with the chitosan microspheres to introduce dithiocarbamate groups and other active groups, making the surface of the microspheres have abundant functional groups, so as to have the ability to adsorb sodium sulfide and complex metal 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 to chitosan microspheres. The above method is simple and feasible, and can prepare modified chitosan microspheres with dithiocarbamate groups, which is beneficial to improving the leaching efficiency of antimony and inhibiting the dissolution of gold into the antimony leaching solution, so it is beneficial to improve the recovery rate of antimony.

[0011] Optionally, the mass concentration of the sodium hydroxide solution in step A is 5% - 10%; the mass ratio of the chitosan microspheres to the sodium hydroxide solution is 1:(40 - 50).

[0012] Optionally, the mass ratio of the chitosan microspheres to carbon disulfide in step A is 1:(3 - 5); the mass ratio of the chitosan microspheres to ethylenediamine is 1:(2 - 2.5).

[0013] By adopting the above technical solution, the mass ratios of carbon disulfide, ethylenediamine and chitosan microspheres are clarified, so that the modification reaction can proceed as expected, ensuring that the modified chitosan microspheres have sufficient active groups to achieve the adsorption of sodium sulfide and the complexation of gold. The appropriate mass ratio can control the degree of the 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 precisely controlling their ratios to chitosan microspheres, the performance of the modified chitosan microspheres can be optimized.

[0014] Optionally, the mass ratio of the antimony sulfide-containing material to the tetrafluoroborate ionic liquid in S1 is 1:(0.3 - 0.5); the tetrafluoroborate ionic liquid is preferably 1-ethyl-3-methylimidazolium tetrafluoroborate.

[0015] By adopting the above technical solution, the appropriate mass ratio can ensure sufficient contact between the ionic liquid and the antimony sulfide-containing material, so that the cations and anions of the ionic liquid can effectively interact with antimony sulfide and antimony ions. 1-ethyl-3-methylimidazolium tetrafluoroborate has good solubility and chemical stability, and can better achieve the activation of antimony sulfide and the stabilization of antimony ions.

[0016] Optionally, when nitrogen protection is carried out in S2, the flow rate of nitrogen introduced is 0.5 - 1.5 L / min, and the pressure range in the leaching tank is 8 - 10 kPa.

[0017] By adopting the above technical solution, an appropriate nitrogen flow rate can timely discharge the air in the reaction system, and maintaining a slightly positive pressure state can prevent external air from entering the leaching tank. The limitation of the pressure range ensures the tightness and stability of the reaction system, provides a good anaerobic environment for the leaching reaction, and thus avoids the oxidation of sodium sulfide.

[0018] Optionally, in S2, the addition amount of N-dodecyl acetamide is 0.5% - 1.5% of the mass of the pulp; the addition amount of the kerosene solution is 3% - 5% of the mass of the pulp; the addition amount of sodium sulfide is 8% - 12% of the mass of the pulp; the addition amount of sodium hydroxide is 2% - 4% of the mass of the pulp; the addition amount of the modified chitosan microspheres is 0.2% - 0.5% of the mass of the pulp; the addition amount of the catalyst is 0.05% - 0.2% of the mass of the pulp.

[0019] Optionally, the catalyst in S2 is any one of copper sulfate and ferrous sulfate.

[0020] By adopting the above technical solution, 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, and thus accelerate the reaction rate of antimony sulfide with reagents such as sodium sulfide and sodium hydroxide, enabling more antimony to be leached in a shorter time.

[0021] Optionally, the elution treatment in S3 includes 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 is completed. The volume ratio of the hydrochloric acid solution to the organic phase is 1:(2 - 3). Stir and elute at 30 - 40 °C for 30 - 45 min, then let it stand for layering, and collect the lower aqueous phase as the eluate.

[0022] Optionally, during the electrowinning treatment in S4, a lead-antimony alloy is used as the anode and stainless steel is used as the cathode, and the cell voltage is controlled at 1.8 - 2.2 V, and the current density is 150 - 200 A / m².

[0023] In summary, the present application has the following beneficial effects: 1. In this application, modified chitosan microspheres and catalysts are used. Since the surface of the modified chitosan microspheres has abundant functional groups, it can adsorb sodium sulfide and make its distribution in the pulp more uniform, increase the contact area between sodium sulfide and antimony sulfide, and promote the dissolution of antimony sulfide. The modified groups (dithiocarbamate groups) on the microspheres have a strong complexing ability for gold, can fix the gold on the surface of the microspheres, and prevent them from entering the antimony leaching solution. And the metal ions in the catalysts (copper sulfate, ferrous sulfate) can participate in the electron transfer process of the reaction, reduce the activation energy of the reaction, and accelerate the reaction rate of antimony sulfide with reagents such as sodium sulfide and sodium hydroxide. Therefore, it has the advantages of improving the leaching efficiency, reducing the subsequent separation cost and the loss of antimony, and thus is conducive to improving the recovery rate of antimony.

[0024] 2. In the method of this application, by introducing nitrogen protection during the S2 leaching process and controlling the inlet flow rate of nitrogen to be 0.5 - 1.5 L / min, a slightly positive pressure state is maintained in the leaching tank. Since the air in the reaction system can be discharged, the contact between oxygen and other oxidizing gases and the leaching solution is reduced, the stability of the leaching solution is maintained, and its oxidation peak potential is increased. Therefore, it has the effect of reducing the possibility of sodium sulfide being oxidized, avoiding the dissolution of gold into the antimony leaching solution, providing a good anaerobic environment for the leaching reaction, and being conducive to improving the recovery rate of antimony subsequently.

[0025] 3. In this application, tetrafluoroborate ionic liquids are used. Since 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid has a unique cation-anion structure, its cation part can interact with the sulfide ions on the surface of antimony sulfide, and the anion part can combine with antimony ions, thereby weakening the strength of the antimony-sulfur bond in antimony sulfide. And some components in the ionic liquid can form stable complexes with antimony ions, restricting the redox reaction of antimony ions. Therefore, it has the effect of making antimony sulfide more easily soluble in the pulp, stabilizing the valence state of antimony ions, keeping them in a stable valence state conducive to subsequent extraction, and improving the recovery rate of antimony. Detailed implementation manners

[0026] The following further elaborates on this application with reference to examples.

[0027] Preparation example of modified chitosan microspheres Preparation example 1 The modified chitosan microspheres are prepared by the following method: A. Add 1 kg of chitosan microspheres to 40 kg of sodium hydroxide solution with a mass concentration of 5%, stir at room temperature for 20 min, then add 3 kg of carbon disulfide and 2 kg of ethylenediamine, and stir and react at room temperature for 3 h to obtain a product mixture; B. Filter the product mixture, take the solid phase, wash it with deionized water until neutral, and then dry it to constant weight at 40 °C to obtain the modified chitosan microspheres.

[0028] Preparation Example 2 The modified chitosan microspheres were prepared by the following method: A. Add 1 kg of chitosan microspheres to 45 kg of sodium hydroxide solution with a mass concentration of 8%, stir at room temperature for 25 min, then add 4 kg of carbon disulfide and 2.2 kg of ethylenediamine, and stir and react at room temperature for 3.5 h to obtain a product mixture; B. Filter the product mixture, take the solid phase, wash it with deionized water until neutral, and then dry it to constant weight at 50 °C to obtain the modified chitosan microspheres.

[0029] Preparation Example 3 The modified chitosan microspheres were prepared by the following method: A. Add 1 kg of chitosan microspheres to 50 kg of sodium hydroxide solution with a mass concentration of 10%, stir at room temperature for 30 min, then add 5 kg of carbon disulfide and 2.5 kg of ethylenediamine, and stir and react at room temperature for 4 h to obtain a product mixture; B. Filter the product mixture, take the solid phase, wash it with deionized water until neutral, and then dry it to constant weight at 60 °C to obtain the modified chitosan microspheres.

[0030] Preparation Example 4 The modified chitosan microspheres are different from those in Preparation Example 1 in that ethylenediamine is not added in this preparation example.

[0031] Preparation Example 5 The modified chitosan microspheres are different from those in Preparation Example 1 in that the addition amount of ethylenediamine in this preparation example is 4 kg.

[0032] Examples The antimony sulfide-containing material used in the examples of this application is antimony-gold concentrate from Xiangxi Gold Mine in Hunan Province, and the composition of the antimony-gold concentrate is shown in Table 1.

[0033] Table 1 Main components of antimony-gold concentrate

[0034] It can be seen from Table 1 that the main chemical components of this kind of antimony-gold concentrate are iron, antimony, and sulfur, but the gold grade is also very high.

[0035] Example 1 A process for wet extraction of antimony from antimony sulfide includes the following steps: S1. Mix 10 kg of antimony-gold concentrate with 3 kg of 1-ethyl-3-methylimidazolium tetrafluoroborate, then add water for pulping, and control the pulping concentration to be 60 wt% to obtain pulp.

[0036] S2. Add the pulp into a leaching tank equipped with a two-way reaction structure, and carry out leaching treatment under a nitrogen protection atmosphere. The upper part inside the leaching tank is the organic phase, which is composed of N-dodecylacetamide and kerosene solution; the lower part inside the leaching tank is the pulp phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added to the pulp phase. The material addition amounts in this step are shown in Table 2. In this step, the modified chitosan microspheres selected are those prepared in Preparation Example 1, and the catalyst selected is ferrous sulfate. The flow rate of nitrogen introduced is 0.5 L / min, and the pressure inside the leaching tank is 8 kPa.

[0037] S3. Add a hydrochloric acid solution with a concentration of 1.5 mol / L to the organic phase after the leaching treatment is completed. The volume ratio of the hydrochloric acid solution to the organic phase is 1:2. Stir and elute at 30 °C for 30 min, then let it stand for stratification, collect the lower aqueous phase as the eluate, and then filter the eluate to obtain an antimony-containing solution.

[0038] S4. Feed the antimony-containing solution into an electrolytic cell for electrowinning treatment. During electrowinning treatment, a lead-antimony alloy is used as the anode and stainless steel is used as the cathode. Control the cell voltage at 1.8 V and the current density at 150 A / m², and use a mechanical scraping device to collect the antimony on the cathode.

[0039] Example 2 A process for wet extraction of antimony from antimony sulfide includes the following steps: S1. Mix 10 kg of antimony-gold concentrate with 4 kg of 1-ethyl-3-methylimidazolium tetrafluoroborate, and then add water for pulping, controlling the pulping concentration at 60 wt% to obtain pulp.

[0040] S2. Add the pulp into a leaching tank equipped with a two-way reaction structure, and carry out leaching treatment under a nitrogen protection atmosphere. The upper part inside the leaching tank is the organic phase, which is composed of N-dodecylacetamide and kerosene solution; the lower part inside the leaching tank is the pulp phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added to the pulp phase. The material addition amounts in this step are shown in Table 2. In this step, the modified chitosan microspheres selected are those prepared in Preparation Example 2, and the catalyst selected is copper sulfate. The flow rate of nitrogen introduced is 1.0 L / min, and the pressure inside the leaching tank is 9 kPa.

[0041] S3. Add a hydrochloric acid solution with a concentration of 2.0 mol / L to the organic phase after the leaching treatment is completed. The volume ratio of the hydrochloric acid solution to the organic phase is 1:2.5. Stir and elute at 35 °C for 38 min, then let it stand for stratification, collect the lower aqueous phase as the eluate, and then filter the eluate to obtain an antimony-containing solution.

[0042] S4. Feed the antimony-containing solution into an electrolytic cell for electrowinning treatment. During the electrowinning treatment, use a lead-antimony alloy as the anode and stainless steel as the cathode. Control the cell voltage at 2.0 V and the current density at 180 A / m², and use a mechanical scraping device to collect the antimony on the cathode.

[0043] Example 3 A process for wet extraction of antimony from antimony sulfide, comprising the following steps: S1. Mix 10 kg of antimony-gold concentrate with 5 kg of 1-ethyl-3-methylimidazolium tetrafluoroborate, then add water for pulping, and control the pulping concentration at 60 wt% to obtain a pulp.

[0044] S2. Add the pulp into a leaching tank equipped with a two-way reaction structure, and conduct leaching treatment under a nitrogen protection atmosphere. The upper part of the leaching tank is an organic phase, which is composed of N-dodecylacetamide and kerosene solution; the lower part of the leaching tank is a pulp phase; during leaching, add sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst to the pulp phase. The material addition amounts in this step are shown in Table 2. In this step, the modified chitosan microspheres are the modified chitosan microspheres prepared in Preparation Example 3, and the catalyst is copper sulfate. The flow rate of nitrogen introduced is 1.5 L / min, and the pressure in the leaching tank is 10 kPa.

[0045] S3. Add a hydrochloric acid solution with a concentration of 2.5 mol / L to the organic phase after the leaching treatment is completed. The volume ratio of the hydrochloric acid solution to the organic phase is 1:3. Stir and elute at 40 °C for 45 min, then let it stand for layer separation, collect the lower aqueous phase as the eluate, and then filter the eluate to obtain an antimony-containing solution.

[0046] S4. Feed the antimony-containing solution into an electrolytic cell for electrowinning treatment. During the electrowinning treatment, use a lead-antimony alloy as the anode and stainless steel as the cathode. Control the cell voltage at 2.2 V and the current density at 200 A / m², and use a mechanical scraping device to collect the antimony on the cathode.

[0047] Table 2 Material usage amounts in S2 of Examples 1-3

[0048] Example 4 A process for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that in S2, the modified chitosan microspheres are the modified chitosan microspheres prepared in Preparation Example 4.

[0049] Example 5 A process for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that in S2, the modified chitosan microspheres are the modified chitosan microspheres prepared in Preparation Example 5.

[0050] Comparative Example Comparative Example 1 A process for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that 1-ethyl-3-methylimidazolium tetrafluoroborate is not added in S1 in this comparative example, and the amount is made up with water.

[0051] Comparative Example 2 A process for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that the S2 step in this comparative example is not carried out under nitrogen protection.

[0052] Comparative Example 3 A process for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that an equal amount of chitosan microspheres are selected to replace the modified chitosan microspheres in S2 of this comparative example.

[0053] Comparative Example 4 A process for wet extraction of antimony from antimony sulfide, which is different from Example 1 in that no catalyst is added in S2 of this comparative example.

[0054] Performance detection test According to the composition table of antimony-gold concentrate in Table 1, it can be known that 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, that is, 270.3 g.

[0055] The antimony extracted in the above Examples 1-5 and Comparative Examples 1-4 was weighed respectively, and the results are shown in Table 3 below. According to the above composition table of antimony-gold concentrate and the calculation process, theoretically, 2703 g of metallic antimony can be extracted from 10 kg of antimony-gold concentrate in this example and comparative examples.

[0056] Table 3 Mass of metallic antimony extracted in Examples 1-5 and Comparative Examples 1-4

[0057] The antimony recovery rates of Examples 1-3 are between 96.2% and 96.6%, which are at a relatively high level. Examples 1-3 completely adopted the process method in this application. The tetrafluoroborate ionic liquid weakens the antimony-sulfur bond strength in antimony sulfide and stabilizes the valence state of antimony ions; nitrogen protection reduces the oxidation of sodium sulfide and avoids the dissolution of gold into the leaching solution; the modified chitosan microspheres make the distribution of sodium sulfide uniform, increase the contact area with antimony sulfide, and complex the alloy ions to prevent them from entering the leaching solution; the catalyst speeds up the reaction rate. The synergistic effect of each factor promotes the dissolution and leaching of antimony sulfide, reduces impurity interference, and improves the antimony recovery rate.

[0058] The antimony recovery rates of Examples 4 and 5 are 94.2% and 94.3% respectively, slightly lower than those of Examples 1-3. This is mainly due to the differences in the preparation conditions of the modified chitosan microspheres. Ethylenediamine was not added in Example 4, and the addition amount of ethylenediamine in Example 5 was different, which may affect the number or activity of surface functional groups of the modified chitosan microspheres, resulting in a slight decrease in the adsorption capacity of sodium sulfide and the complexation ability of gold, further affecting the leaching and separation of antimony and slightly reducing the recovery rate. However, it is still relatively high compared to Comparative Examples 1-4, indicating good overall process stability.

[0059] The recovery rate of Comparative Example 1 is 91.1%. In this comparative example, tetrafluoroborate ionic liquid was not added in S1. The lack of ionic liquid weakens the antimony-sulfur bond in antimony sulfide, increasing the difficulty of antimony sulfide dissolution. Moreover, it is unable to stabilize the valence state of antimony ions, and the redox reaction of antimony ions is likely to occur, which is not conducive to subsequent extraction, resulting in a decrease in the antimony recovery rate.

[0060] The recovery rate of Comparative Example 2 is 87.6%. The S2 step was not carried out under nitrogen protection. Oxidizing gases such as oxygen oxidize sodium sulfide into polysulfides and thiosulfates, which will dissolve gold into the antimony leaching solution, increasing the separation cost and also affecting the antimony leaching reaction, resulting in a decrease in the antimony recovery rate.

[0061] The recovery rate of Comparative Example 3 is 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, cannot effectively adsorb sodium sulfide to make it evenly distributed, and are also difficult to complex gold ions, reducing the dissolution efficiency of antimony sulfide and making gold easily enter the leaching solution, resulting in a significant decrease in the antimony recovery rate.

[0062] The recovery rate of Comparative Example 4 is 86.1%. A catalyst was not added in S2. The lack of a catalyst cannot effectively reduce the reaction activation energy, resulting in a slower reaction rate between antimony sulfide and reagents such as sodium sulfide and sodium hydroxide, and less antimony is leached in the same time, thus reducing the antimony recovery rate.

[0063] This specific embodiment is only an explanation of the present application and does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A process for wet extraction of antimony from antimony sulfide, characterized in that, It includes the following steps: S1. After mixing the antimony sulfide-containing material with the tetrafluoroborate ionic liquid, water is added for pulping to obtain a pulp; S2. The pulp is added into a leaching tank provided with a two-way reaction structure, and leaching treatment is carried out under a nitrogen protection atmosphere. The upper part inside the leaching tank is an organic phase, which is composed of N-dodecylacetamide and a kerosene solution; the lower part inside the leaching tank is a pulp phase; during leaching, sodium sulfide, sodium hydroxide, modified chitosan microspheres and a catalyst are added into the pulp phase; S3. The organic phase after the leaching treatment is eluted, the eluate is collected, and then the eluate is filtered to obtain an antimony-containing solution; S4. The antimony-containing solution is sent into an electrolytic cell for electrowinning treatment, and antimony on the cathode is collected by a mechanical scraper device.

2. The process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: The modified chitosan microspheres are prepared by the following method: A. The chitosan microspheres are added into a sodium hydroxide solution, stirred at room temperature for 20 - 30 min., then carbon disulfide and ethylenediamine are added, and stirred and reacted at room temperature for 3 - 4 h to obtain a product mixture; B. The product mixture is filtered, the solid phase is washed with deionized water until neutral, and then dried at 40 - 60 °C to constant weight to obtain the modified chitosan microspheres.

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

4. The process method for wet extraction of antimony from antimony sulfide according to claim 3, 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).

5. A process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: In S1, 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 preferably 1-ethyl-3-methylimidazolium tetrafluoroborate.

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

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

8. A 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.

9. A process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: The elution treatment in S3 includes the following steps: A hydrochloric acid solution with a concentration of 1.5 - 2.5 mol / L is added into the organic phase after the leaching treatment. The volume ratio of the hydrochloric acid solution to the organic phase is 1:(2 - 3), stirred and eluted at 30 - 40 °C for 30 - 45 min, then left to stand for stratification, and the lower aqueous phase is collected as the eluate.

10. A process for wet extraction of antimony from antimony sulfide according to claim 1, characterized in that: During the electrowinning treatment in S4, a lead-antimony alloy is used as the anode, stainless steel is used as the cathode, the cell voltage is controlled at 1.8 - 2.2 V, and the current density is 150 - 200 A / m².

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