Method for synergistic recovery of valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean solution

Abstract

The present invention belongs to the field of metallurgy and relates to a method for synergistically recovering valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean solution. The method comprises the following steps: S1: mixing the arsenic-antimony fly ash with the antimony electrodeposition lean solution for an alkaline leaching reaction, whereupon antimony oxide slag and an arsenic-rich antimony solution are obtained; S2: adjusting the pH of the arsenic-antimony solution obtained in step S1 to a pH of 7-8, whereupon antimony sulfide slag, hydrogen sulfide gas, and an arsenic-rich solution are obtained; and S3: adjusting the pH of the arsenic-rich solution obtained in step S2 to a pH of 1-2, whereupon arsenic sulfide slag, hydrogen sulfide gas, and a sodium sulfate solution are obtained. The present invention utilizes the synergistic reaction of the arsenic-antimony fly ash with the antimony electrodeposition lean solution, and subsequently separates arsenic and antimony from the arsenic-rich antimony solution by reacting sodium thioarsenite (Na3AsS3) and sodium thioantimonite (Na3SbS3) with acid in different sequences. The separation and recovery steps are simple and the recovery rate is high.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for collaboratively recovering valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean liquid. Background Art

[0002] Arsenic and its low-valent compounds exhibit significant volatility. During the pyrometallurgical smelting process of non-ferrous metals, most arsenic volatilizes as arsenic trioxide (As2O3) and enters various types of dust, such as dust from lead anode mud reverberatory furnaces, dust from copper converters, and dust from tin smelting. Due to the similar chemical properties of arsenic and antimony, the smelting process easily forms a composite dust containing high concentrations of arsenic and antimony, known as arsenic-antimony dust (or arsenic-antimony dust). The non-ferrous smelting industry generates a large amount of arsenic-antimony dust annually. Most companies store and dispose of it in stockpiles, which leads to several problems. For example, the high content of valuable metals such as antimony and arsenic in the dust makes it a significant waste of resources if left unused. Furthermore, the dust contains a large amount of the harmful element arsenic, which can dissolve into water bodies through rainwater erosion, leaching, or microbial action, causing significant pollution to water sources, soil, and flora and fauna. Therefore, whether from the perspective of environmental protection or economic benefits, the treatment of arsenic antimony dust is very valuable. Effective and economical recycling of arsenic antimony dust can reduce pollution while obtaining valuable secondary metal resources.

[0003] Currently, the treatment of antimony-bearing gold concentrates typically involves alkaline leaching and antimony electrolysis to separate gold and antimony and recover the antimony. The resulting antimony electrolysis lean liquor is treated by freeze-crystallization to produce crystalline antimony salt. The leached residue is then processed using either pyrometallurgical or hydrometallurgical processes to recover valuable metals such as gold and silver. While crystalline antimony salt primarily consists of sodium sulfide, it contains high levels of sodium hydrosulfide and sodium thiosulfate, making it unsuitable for direct sale. Furthermore, during long-term storage, the sodium sulfide deliquesces when exposed to air and deteriorates due to acidification, continuously releasing hydrogen sulfide gas, placing significant pressure on environmental protection and production safety. Therefore, directly treating the antimony electrolysis lean liquor to avoid the production of crystalline antimony salt is highly desirable. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for collaboratively recovering valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean solution.

[0005] The specific technical solutions are as follows:

[0006] The method for recovering valuable elements by synergistically using arsenic-antimony soot and antimony electrodeposition lean solution comprises the following steps:

[0007] S1: mixing arsenic antimony fly ash with antimony electrodeposition lean solution to carry out alkaline leaching reaction, and obtaining antimony oxide slag and arsenic antimony rich solution after the reaction;

[0008] S2: adjusting the pH of the arsenic-rich antimony solution obtained in step S1 to 7-8. After the reaction is completed, antimony sulfide slag, hydrogen sulfide gas, and arsenic-rich solution are obtained;

[0009] S3: The arsenic-rich solution obtained in step S2 is adjusted to a pH of 1-2. After the reaction is completed, arsenic sulfide slag, hydrogen sulfide gas, and sodium sulfate solution are obtained.

[0010] The arsenic antimony ash comes from the ash produced in the antimony refining process, and the antimony electrodeposition lean solution comes from the lean solution produced by alkaline leaching and electrowinning of antimony-containing gold concentrate.

[0011] Specifically, the main component contents of the arsenic-antimony fly ash are: As content 25wt%~40wt%, Sb content 35wt%~50wt%, Cu content 0.01wt%~0.05wt%, Pb content 0.05wt%~0.10wt%, and Bi content 0.01wt%~0.05wt%.

[0012] Specifically, the main component contents of the antimony electrodeposition lean solution are: Sb content 40-50 g / L, Na2S content 70-90 g / L, NaOH content 35-45 g / L, and As content 0.1-1.5 g / L.

[0013] The reaction mechanism of the present invention is as follows:

[0014] The present invention utilizes the synergistic reaction of arsenic-antimony fly ash and antimony electrodeposition lean liquid to recover the valuable elements therein, and achieves the purpose of separating arsenic and antimony in the arsenic-antimony fly ash by controlling the reaction conditions; since the antimony in the antimony electrodeposition lean liquid exists in the form of sodium thioantimonite (Na3SbS3), the obtained arsenic-rich antimony liquid contains sodium thioantimonite (Na3SbS3) and sodium thioarsenite (Na3AsS3), and subsequently, the arsenic and antimony in the arsenic-rich antimony liquid are further separated by reacting sodium thioarsenite (Na3AsS3) and sodium thioantimonite (Na3SbS3) with acid in different orders.

[0015] In step S1, arsenic trioxide in arsenic antimony ash can react with sodium hydroxide and sodium sulfide in antimony electrodeposition lean solution at room temperature to obtain Na3AsS3, which is dissolved in arsenic antimony rich solution. However, antimony trioxide in arsenic antimony ash reacts with concentrated sodium hydroxide and sodium sulfide only under heating conditions, and does not react with low-concentration sodium hydroxide and sodium sulfide at room temperature. The main reaction is:

[0016] As2O3+6NaOH→2Na3AsO3+3H2O;

[0017] Na3AsO3+3Na2S+3H2O→Na3AsS3+6NaOH.

[0018] Furthermore, in step S1, the molar ratio of arsenic in the arsenic-antimony fly ash to sodium sulfide in the antimony electrodeposition lean solution is (0.3-0.6):1.

[0019] Among them, As in antimony oxide slag is ≤1.0wt%, and Sb is ≥65wt%; the As content in arsenic-rich antimony liquid is 20~50g / L, and the Sb content is 40~50g / L.

[0020] Furthermore, in step S1, the reaction temperature is 5-25° C., and the reaction time is 2-6 h.

[0021] Preferably, in step S1, the antimony oxide slag is returned to the antimony refining system to recover antimony.

[0022] In step S2, sodium thioantimonite (Na3SbS3) in the arsenic-rich antimony solution reacts with acid at a pH of 7-8 to generate antimony sulfide slag, which is then separated from sodium thioarsenite (Na3AsS3) in the arsenic-rich antimony solution. The main reactions are:

[0023] 2Na3SbS3+3H2SO4→Sb2S3↓+3H2S↑+3Na2SO4;

[0024] H2SO4+2NaOH→Na2SO4+2H2O;

[0025] H2SO4+Na2S→Na2SO4+H2S↑.

[0026] Furthermore, in step S2, the pH of the arsenic-rich antimony solution is adjusted using dilute sulfuric acid, and the concentration of the dilute sulfuric acid is 1 wt% to 3 wt%.

[0027] Furthermore, in step S2, the reaction temperature is 5-25° C., and the reaction time is 0.5-1.5 h.

[0028] Among them, As in antimony sulfide slag is ≤1.0wt%, and Sb is ≥60wt%; the As content in arsenic-rich liquid is 15~45g / L, and the Sb content is <0.50mg / L.

[0029] Preferably, in step S2, the antimony sulfide slag is returned to the antimony refining system to recover antimony.

[0030] Preferably, in step S2, the hydrogen sulfide gas is sent to a water treatment system.

[0031] In step S3, sodium thioarsenite (Na3AsS3) in the arsenic-rich solution reacts with acid at a pH of 1-2 to produce arsenic sulfide slag. The main reactions are:

[0032] 2Na3AsS3+3H2SO4→As2S3↓+3H2S↑+3Na2SO4.

[0033] Furthermore, in step S3, the pH of the arsenic-rich solution is adjusted using dilute sulfuric acid, and the concentration of the dilute sulfuric acid is 1 wt% to 3 wt%.

[0034] Furthermore, in step S3, the reaction temperature is 70-90° C., and the reaction time is 1-3 h.

[0035] Among them, Sb≤0.1wt%, As≥50wt% in arsenic sulfide slag; Sb≤0.3mg / L, As≤0.3mg / L in sodium sulfate solution.

[0036] Preferably, in step S3, the arsenic sulfide slag is returned to the arsenic refining system to recover arsenic.

[0037] Preferably, in step S3, the hydrogen sulfide gas is sent to a water treatment system.

[0038] Preferably, in step S3, the sodium sulfate solution is subjected to multiple-effect evaporation to recover sodium sulfate.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention utilizes the synergistic reaction of arsenic-antimony fly ash and antimony electrodeposition lean liquid to achieve the purpose of separating arsenic and antimony in the arsenic-antimony fly ash; the generated sodium thioantimonite reacts with acid first, and then the sodium thioarsenite reacts with acid; by controlling the reaction conditions, the arsenic and antimony in the arsenic-antimony-rich liquid are further separated, and the valuable elements therein are recovered; the separation and recovery steps are simple and the recovery rate is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The figure is a process flow chart of a method for collaboratively recovering valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean solution in a specific embodiment. DETAILED DESCRIPTION

[0042] The embodiments of the present invention are described in further detail below with reference to the accompanying drawings and examples. The following examples are intended to illustrate the present invention but are not intended to limit the scope of the invention. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources. Example 1

[0043] A method for recovering valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean solution in a coordinated manner, wherein:

[0044] The arsenic antimony soot is obtained from soot produced during the antimony refining process, and its main components are: As 25.32wt%, Sb 48.56wt%, Cu 0.01wt%, Pb 0.05wt%, and Bi 0.01wt%.

[0045] The antimony electrodeposition lean solution is derived from the lean solution produced by alkaline leaching and electrowinning of antimony-containing gold concentrate, and its main components are: Sb content of 49.55 g / L, Na2S content of 89.54 g / L, NaOH content of 44.21 g / L, and As content of 1.42 g / L.

[0046] The steps are as follows:

[0047] S1: Add arsenic-antimony fly ash into the reactor, add antimony electrodeposition lean solution according to the molar ratio of arsenic in arsenic-antimony fly ash to sodium sulfide in antimony electrodeposition lean solution of 0.3:1, and react at 5°C for 2 hours. After the reaction is completed, filter and the filter residue is antimony oxide residue (As content is 0.52wt%, Sb content is 67.25wt%), which is returned to the antimony refining system to recover antimony trioxide. The filtrate is arsenic-rich antimony solution and enters the next process;

[0048] S2: The arsenic-rich antimony liquid obtained in step S1 is added to a reactor with a circulating water jacket. The reaction temperature in the reactor is controlled at 5°C by circulating water. 1 wt% dilute sulfuric acid is added to adjust the pH of the solution to 7. After reacting for 1.5 hours, the solution is filtered. The filter residue is antimony sulfide residue (As content is 0.68 wt%, Sb content is 64.25 wt%), which is returned to the antimony refining system to recover antimony trioxide. The generated hydrogen sulfide gas is sent to the water treatment system. The filtrate is the arsenic-rich liquid and enters the next process.

[0049] S3: The arsenic-rich solution obtained in step S2 is added to a reactor, and 1 wt% dilute sulfuric acid is added to adjust the pH of the solution to 1. After reacting at 70°C for 3 hours, the solution is filtered. The filter residue is arsenic sulfide residue (As content is 58.24 wt%, Sb content is 0.03 wt%), which is returned to the arsenic refining system to recover arsenic trioxide. The generated hydrogen sulfide gas is sent to the water treatment system. The filtrate is a sodium sulfate solution (As content is 0.21 mg / L, Sb content is 0.17 mg / L). After neutralization with alkali, the sodium sulfate is recovered by multi-effect evaporation. Example 2

[0050] A method for recovering valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean solution in a coordinated manner, wherein:

[0051] The arsenic antimony soot is obtained from soot produced during the antimony refining process, and its main components are: As 39.24wt%, Sb 35.14wt%, Cu 0.04wt%, Pb 0.08wt%, and Bi 0.05wt%.

[0052] The antimony electrodeposition lean solution is derived from the lean solution produced by alkaline leaching and electrowinning of antimony-containing gold concentrate, and its main components are: Sb content of 40.34 g / L, Na2S content of 71.57 g / L, NaOH content of 35.04 g / L, and As content of 0.21 g / L.

[0053] The steps are as follows:

[0054] S1: Add arsenic-antimony fly ash into the reactor, add antimony electrodeposition lean solution according to the molar ratio of arsenic in arsenic-antimony fly ash to sodium sulfide in antimony electrodeposition lean solution of 0.6:1, and react at 25°C for 6 hours. After the reaction is completed, filter and the filter residue is antimony oxide residue (As content is 0.34wt%, Sb content is 66.57wt%), which is returned to the antimony refining system to recover antimony trioxide. The filtrate is arsenic-rich antimony solution and enters the next process;

[0055] S2: The arsenic-rich antimony liquid obtained in step S1 is added to a reactor with a circulating water jacket. The reaction temperature in the reactor is controlled at 25°C by circulating water. 3wt% dilute sulfuric acid is added to adjust the pH of the solution to 8. After reacting for 0.5h, the solution is filtered. The filter residue is antimony sulfide residue (As content is 0.54wt%, Sb content is 64.67wt%), which is returned to the antimony refining system to recover antimony trioxide. The generated hydrogen sulfide gas is sent to the water treatment system. The filtrate is the arsenic-rich liquid and enters the next process.

[0056] S3: The arsenic-rich solution obtained in step S2 is added to a reactor, and 3 wt% dilute sulfuric acid is added to adjust the pH of the solution to 2. After reacting at 90°C for 1 hour, the solution is filtered. The filter residue is arsenic sulfide residue (As content is 56.57 wt%, Sb content is 0.03 wt%), which is returned to the arsenic refining system to recover arsenic trioxide. The generated hydrogen sulfide gas is sent to the water treatment system. The filtrate is a sodium sulfate solution (As content is 0.23 mg / L, Sb content is 0.15 mg / L). After neutralization with alkali, the sodium sulfate is recovered by multi-effect evaporation. Example 3

[0057] A method for recovering valuable elements from arsenic-antimony fly ash and antimony electrodeposition lean solution in a coordinated manner, wherein:

[0058] The arsenic antimony soot is obtained from soot produced during the antimony refining process, and its main components are: As 32.14 wt%, Sb 42.57 wt%, Cu 0.03 wt%, Pb 0.09 wt%, and Bi 0.03 wt%.

[0059] The antimony electrodeposition lean solution is derived from the lean solution produced by alkaline leaching and electrowinning of antimony-containing gold concentrate, and its main components are: Sb content of 45.21 g / L, Na2S content of 81.24 g / L, NaOH content of 41.21 g / L, and As content of 1.21 g / L.

[0060] The steps are as follows:

[0061] S1: Add arsenic-antimony fly ash into the reactor, add antimony electrodeposition lean solution according to the molar ratio of arsenic in arsenic-antimony fly ash to sodium sulfide in antimony electrodeposition lean solution of 0.5:1, and react at 15°C for 4 hours. After the reaction is completed, filter and the filter residue is antimony oxide residue (As content is 0.31wt%, Sb content is 67.24wt%), which is returned to the antimony refining system to recover antimony trioxide. The filtrate is arsenic-rich antimony solution and enters the next process;

[0062] S2: The arsenic-rich antimony liquid obtained in step S1 is added to a reactor with a circulating water jacket. The reaction temperature in the reactor is controlled at 15°C by circulating water. 2 wt% dilute sulfuric acid is added to adjust the pH of the solution to 7.5. After reacting for 1.0 h, the solution is filtered. The filter residue is antimony sulfide slag (As content is 0.24 wt%, Sb content is 66.32 wt%), which is returned to the antimony refining system to recover antimony trioxide. The generated hydrogen sulfide gas is sent to the water treatment system. The filtrate is the arsenic-rich liquid and enters the next process.

[0063] S3: The arsenic-rich solution obtained in step S2 is added to a reactor, and 2 wt% dilute sulfuric acid is added to adjust the pH of the solution to 1.5. After reacting at 80°C for 2 hours, the solution is filtered. The filter residue is arsenic sulfide residue (As content is 54.36 wt%, Sb content is 0.02 wt%), which is returned to the arsenic refining system to recover arsenic trioxide. The generated hydrogen sulfide gas is sent to the water treatment system. The filtrate is a sodium sulfate solution (As content is 0.25 mg / L, Sb content is 0.27 mg / L). After neutralization with alkali, the sodium sulfate is recovered by multi-effect evaporation. Comparative Example 1

[0064] Refer to Example 1, except that: in step S2, 1 wt % dilute sulfuric acid is added to adjust the pH of the solution to 1. Comparative Example 2

[0065] Refer to Example 1, except that: in step S3, 1 wt % dilute sulfuric acid is added to adjust the pH of the solution to 7.

[0066] test

[0067] The Sb and As contents in the antimony oxide slag, arsenic-rich antimony liquid obtained in step S1 of Examples 1 to 3 and Comparative Examples 1 to 2, the antimony sulfide slag and arsenic-rich liquid obtained in step S2, the arsenic sulfide slag obtained in step S3, and the sodium sulfate solution were detected, and the results are shown in Table 1. The recovery rates of each valuable metal in Examples 1 to 3 and Comparative Examples 1 to 2 were calculated, and the results are shown in Table 2.

[0068] Among them, the Sb and As contents in arsenic-rich antimony liquid, arsenic-rich liquid and sodium sulfate solution are detected with reference to "Chemical Analysis Methods for Copper Smelting Fume Part 10: Determination of Copper, Lead, Zinc, Bismuth, Arsenic, Indium, Silver, Cadmium, Antimony, Calcium, Magnesium and Iron Contents by Inductively Coupled Plasma Atomic Emission Spectrometry (YS / T 1512.10-2022)".

[0069] Antimony in antimony oxide slag shall be tested in accordance with the "Chemical Analysis Method for Crude Antimony Oxide for Export - Determination of Total Antimony Content (SN / T 1031.2-2001)", and arsenic in antimony oxide slag shall be tested in accordance with the "Chemical Analysis Method for Crude Antimony Oxide for Import and Export - Determination of Arsenic Content (SN / T1031.7-2003)".

[0070] Antimony in antimony sulfide slag is detected according to the "Chemical Analysis Method of Antimony Trisulfide Part 1: Determination of Antimony Content - Cerium Sulfate Titration Method (YS / T 239.1-2010)", and arsenic in antimony sulfide slag is detected according to the "Chemical Analysis Method of Antimony Trisulfide Part 5: Determination of Arsenic Content - Arsenic-Molybdenum Blue Spectrophotometry (YS / T 239.5-2010)".

[0071] Antimony in arsenic sulfide slag is detected according to the "Chemical Analysis Methods for Arsenic Part 4: Determination of Bismuth, Antimony and Sulfur Contents by Inductively Coupled Plasma Atomic Emission Spectrometry (YS / T 519.4-2009)", and arsenic in arsenic sulfide slag is detected according to the "Chemical Analysis Methods for Arsenic Part 1: Determination of Arsenic Content by Potassium Bromate Titration (YS / T 519.1-2009)".

[0072] Table 1 As and Sb contents

[0073]

[0074] Table 2 Recovery rate of valuable metals

[0075]

[0076] As shown in Tables 1 and 2, using the method of the present invention (Examples 1-3), As ≤ 1.0 wt% and Sb ≥ 65 wt% in the antimony oxide slag; As ≤ 1.0 wt% and Sb ≥ 60 wt% in the antimony sulfide slag; Sb ≤ 0.1 wt% and As ≥ 50 wt% in the arsenic sulfide slag; Sb ≤ 0.3 mg / L and As ≤ 0.3 mg / L in the sodium sulfate solution; arsenic recovery rates all reached over 98%, and antimony recovery rates all reached over 99%, indicating good arsenic and antimony separation in arsenic-antimony fly ash and antimony electrodeposition lean solution, with high recovery rates. In Comparative Example 1, adjusting the solution pH to 1 in step S2 resulted in the inability to separate arsenic and antimony in the solution. The antimony sulfide slag contained 24.05 wt% arsenic and 46.16 wt% antimony, resulting in an antimony recovery rate of only 50.11%, indicating ineffective arsenic recovery. In Comparative Example 2, adjusting the solution pH to 7 in step S3 resulted in incomplete arsenic precipitation in the solution, resulting in a sodium sulfate solution containing 14210 mg / L arsenic, and an arsenic recovery rate of only 44.99%.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for recovering valuable elements by synergistically using arsenic-antimony fly ash and antimony electrodeposition lean solution, characterized in that: The steps include: S1: mixing arsenic antimony fly ash with antimony electrodeposition lean solution to carry out alkaline leaching reaction, and obtaining antimony oxide slag and arsenic antimony rich solution after the reaction; S2: adjusting the pH of the arsenic-rich antimony solution obtained in step S1 to 7-8. After the reaction is completed, antimony sulfide slag, hydrogen sulfide gas, and arsenic-rich solution are obtained; S3: adjusting the pH of the arsenic-rich solution obtained in step S2 to 1-2. After the reaction is completed, arsenic sulfide slag, hydrogen sulfide gas, and sodium sulfate solution are obtained; In step S1, the reaction temperature is 5-25° C., and the reaction time is 2-6 h. The main component contents of the antimony electrodeposition lean solution are: Sb content 40-50 g / L, Na2S content 70-90 g / L, NaOH content 35-45 g / L, and As content 0.1-1.5 g / L.

2. The method according to claim 1, wherein: In step S1, the molar ratio of arsenic in the arsenic-antimony fly ash to sodium sulfide in the antimony electrodeposition lean solution is (0.3-0.6):

1.

3. The method according to claim 1, wherein: In step S2, the pH of the arsenic-rich antimony solution is adjusted using dilute sulfuric acid, wherein the concentration of the dilute sulfuric acid is 1 wt% to 3 wt%.

4. The method according to claim 1, wherein: In step S2, the reaction temperature is 5-25° C., and the reaction time is 0.5-1.5 h.

5. The method according to claim 1, wherein: In step S3, the pH of the arsenic-rich solution is adjusted using dilute sulfuric acid, wherein the concentration of the dilute sulfuric acid is 1 wt % to 3 wt %.

6. The method according to claim 1, wherein: In step S3, the reaction temperature is 70-90° C., and the reaction time is 1-3 h.

7. The method according to claim 1, wherein: In step S1, the antimony oxide slag is returned to the antimony refining system to recover antimony; in step S2, the antimony sulfide slag is returned to the antimony refining system to recover antimony.

8. The method according to claim 1, wherein: In step S3, the arsenic sulfide slag is returned to the arsenic refining system to recover arsenic.

9. The method according to claim 1, wherein: In step S3, the sodium sulfate solution is subjected to multiple-effect evaporation to recover sodium sulfate.

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