Comprehensive recovery method for antimony-containing gold concentrate

Abstract

The present invention belongs to the field of metallurgy technology and relates to a comprehensive recovery method for antimony-containing gold concentrate, comprising the following steps: S1: mixing and slurrying the antimony-containing gold concentrate and an antioxidant, then adding sodium sulfide and sodium hydroxide to obtain a slurry, and obtaining a leachate and a leaching residue after the reaction; S2: electrolyzing the leachate obtained in step S1 to obtain crude antimony and a barren solution; wherein, in step S1, the antioxidant is a mixture of sodium ascorbate and disodium ethylenediaminetetraacetic acid. The present invention utilizes Na2S to leach antimony from the antimony-containing gold concentrate under alkaline conditions. In order to avoid the formation of S during the leaching process, 2‑ Oxidized to S x 2‑ , and then reacts with Au to form AuS soluble in alkaline solution x The present invention adds an antioxidant during the leaching process, which can significantly reduce the leaching of gold in the antimony-containing gold concentrate and improve the gold recovery rate.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a comprehensive recovery method for antimony-containing gold concentrate. Background Art

[0002] A notable characteristic of antimony-bearing gold concentrate is that antimony exists primarily in the form of antimony sulfide. Alkaline hydrometallurgy involves the targeted conversion of antimony sulfide in the mineral into sodium thioantimonite using sodium sulfide in an alkaline environment. The addition of sodium hydroxide during the leaching process primarily prevents the formation of toxic hydrogen sulfide gas and further prevents the sulfur in the sodium sulfide from oxidizing to polysulfides in the leachate. The formation of polysulfides significantly promotes gold leaching. Therefore, the addition of sodium hydroxide effectively reduces the dissolution of gold in the solution and minimizes precious metal loss from the mineral. However, gold losses in this method remain high.

[0003] In response to this situation, researchers have made different attempts. Some have studied the leaching principle of polysulfides and used air oxidation to preferentially oxidize the polysulfides in the leachate, causing them to decompose, thereby reducing the effective components of the leached gold and achieving the effect of inhibiting gold leaching. However, in actual operation, while the polysulfides are oxidized, the sulfides are also oxidized to form polysulfides, so this method fails to significantly reduce gold loss. CN 114941078 A discloses adding an inhibitor to an alkaline solution, which is one or more of manganese powder, iron powder, and reducing carbon powder; CN 109881004 A discloses adding a certain amount of zinc powder to the antimony gold concentrate when it is mined. Although these two methods can reduce gold leaching, the added inhibitors are solid, which significantly increases the amount of leaching residue, thereby significantly increasing the cost of subsequent gold recovery. In addition, the added valuable elements such as manganese powder, iron powder, and zinc powder are difficult to recover during subsequent processing. Summary of the Invention

[0004] The present invention aims to overcome the deficiencies of the prior art and provides a comprehensive recovery method for antimony-containing gold concentrate.

[0005] The specific technical solutions are as follows:

[0006] A comprehensive recovery method for antimony-containing gold concentrate comprises the following steps:

[0007] S1: mixing and slurrying the antimony-containing gold concentrate and the antioxidant, then adding sodium sulfide and sodium hydroxide to obtain a slurry, and obtaining a leachate and a leach residue after reaction;

[0008] S2. Electrolytically depositing the leaching solution obtained in step S1 to obtain crude antimony and lean solution;

[0009] Wherein, in step S1, the antioxidant is a mixture of sodium ascorbate and disodium edetate, and the molar ratio of sodium ascorbate to disodium edetate is (1-2):1.

[0010] Among them, the main components of antimony-containing gold concentrate are: Au content 20~80g / t, Ag content 5~20g / t, Sb content 5wt%~15wt%, S content 10wt%~25wt%, and Zn content ≤0.3wt%.

[0011] The reaction mechanism of the present invention is as follows:

[0012] The present invention uses Na2S to leach antimony from antimony-containing gold concentrate under alkaline conditions. In order to avoid S 2- Oxidized to S x 2- , and then reacts with Au to form AuS soluble in alkaline solution x The present invention adds an antioxidant during the leaching process, which can significantly reduce the leaching of gold in the antimony-containing gold concentrate and improve the gold recovery rate.

[0013] In step S1, Sb2S3 in the antimony-bearing gold concentrate reacts with Na2S under alkaline conditions to generate sodium thioantimonite Na3SbS3, which is retained in the leachate. Part of the zinc reacts with sodium hydroxide to generate Na2[Zn(OH)4]. 2- Under the catalysis of Na2[Zn(OH)4], it easily reacts with oxygen to generate polysulfide S which easily reacts with Au. x 2- , disodium edetate and sodium ascorbate are added as antioxidants. On the one hand, disodium edetate in the antioxidant reacts with Na2[Zn(OH)4] in the solution to form a zinc chelate, which avoids the reaction of Na2[Zn(OH)4] as a catalyst to catalyze the oxidation of S in the solution. 2- Reacts with oxygen; on the other hand, sodium ascorbate reacts preferentially with oxygen dissolved in the solution, indirectly inhibiting the reaction of sodium sulfide with oxygen. The main reactions are:

[0014] Sb2S3+3Na2S→2Na3SbS3;

[0015] Zn+2NaOH+2H2O→Na2[Zn(OH)4]+H2;

[0016] 4NaC6H7O6+O2→4NaC6H6O6+2H2O;

[0017] C 10 H 14 N2Na2O8+Na2Zn(OH)4→C 10 H 12N2Na2O8Zn+2NaOH+2H2O.

[0018] Furthermore, in step S1, the total amount of the antioxidant is 0.5 wt% to 2.5 wt% of the total amount of the antimony-containing gold concentrate.

[0019] Furthermore, in step S1, the solid-liquid mass ratio in the slurry is 1:(2~4).

[0020] Furthermore, in step S1, the concentration of sodium sulfide in the slurry is 5-20 g / L, and the concentration of sodium hydroxide in the slurry is 50-100 g / L.

[0021] Furthermore, in step S1, sodium sulfide and sodium hydroxide are added to the slurry during the reaction process, and the concentration of sodium sulfide in the slurry is controlled to be 5-20 g / L, and the concentration of sodium hydroxide in the slurry is controlled to be 50-100 g / L.

[0022] Furthermore, in step S1, the reaction temperature is 40-95° C., and the reaction time is 4-8 h.

[0023] Preferably, in step S1, the leached slag is sequentially passed through a pyrometallurgical smelting system and a rare earth recovery system to recover gold and silver.

[0024] In step S2, sodium thioantimonite Na3SbS3 in the leachate is converted into crude antimony under electrolytic conditions. The main reactions are:

[0025] 4Na3SbS3+12NaOH→4Sb+12Na2S+6H2O+3O2.

[0026] Furthermore, in step S2, the electrolytic deposition operation is specifically as follows: the cell voltage is 2.5-3.0V, the current density is 250-300A / m 2 , the electrode distance is 110mm, the electrodeposition temperature is 70~80℃, and the electrodeposition time is 4~5 days.

[0027] Preferably, in step S2, the lean liquid is subjected to an evaporative cooling system to recover sodium sulfide, and the obtained mother liquor is returned to step S1.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention uses Na2S to leach antimony from antimony-containing gold concentrate under alkaline conditions. In order to avoid S 2- Oxidized to S x 2- , and then reacts with Au to form AuS soluble in alkaline solution x The present invention adds disodium ethylenediaminetetraacetic acid and sodium ascorbate as antioxidants, and the synergistic effect of the two can significantly reduce the leaching of gold in the antimony-containing gold concentrate, improve the gold recovery rate, and the process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a process flow chart of the comprehensive recovery method of antimony-containing gold concentrate in a specific implementation method. DETAILED DESCRIPTION

[0031] 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

[0032] A comprehensive recovery method for antimony-containing gold concentrate, wherein:

[0033] The main components of the antimony-bearing gold concentrate are: Au content 20.32g / t, Ag content 5.45g / t, Sb content 14.57wt%, S content 24.86wt%, and Zn content 0.28wt%.

[0034] The steps are as follows:

[0035] S1: adding antimony-containing gold concentrate to a reactor, then adding sodium ascorbate and disodium edetate to the reactor, slurrying with water, then adding sodium sulfide and sodium hydroxide to obtain a slurry, so that the solid-liquid mass ratio in the slurry is 1:2, the sodium sulfide concentration in the slurry is 20 g / L, and the sodium hydroxide concentration in the slurry is 100 g / L, then raising the temperature of the reactor to 95°C and reacting for 4 hours. During the reaction, sodium sulfide and sodium hydroxide are added to the slurry to control the sodium sulfide concentration in the slurry to 20 g / L and the sodium hydroxide concentration in the slurry to 100 g / L. After the reaction is completed, leachate and leach residue are obtained by solid-liquid separation, and the leach residue is successively recovered through a pyrometallurgical system and a rare earth recovery system to recover gold and silver ingots; wherein the molar ratio of sodium ascorbate and disodium edetate is 1:1, and the total amount of sodium ascorbate and disodium edetate is 2.5wt% of the total amount of the antimony-containing gold concentrate;

[0036] S2 The leachate obtained in step S1 is heated at a cell voltage of 2.5 V and a current density of 250 A / m 2 Electrolysis was carried out under the conditions of an electrode distance of 110 mm and an electrode deposition temperature of 70° C. After 4 days, the electrolysis was completed to obtain crude antimony and lean solution. The lean solution was recovered with sodium sulfide through an evaporative cooling system, and the mother liquor was returned to step S1. Example 2

[0037] A comprehensive recovery method for antimony-containing gold concentrate, wherein:

[0038] The main components of the antimony-bearing gold concentrate are: Au content 79.21g / t, Ag content 18.96g / t, Sb content 5.37wt%, S content 11.24wt%, and Zn content 0.12wt%.

[0039] The steps are as follows:

[0040] S1: adding the antimony-containing gold concentrate to the reactor, then adding sodium ascorbate and disodium edetate to the reactor, slurrying with water, and then adding sodium sulfide and sodium hydroxide to obtain a slurry, so that the solid-liquid mass ratio in the slurry is 1:3, the sodium sulfide concentration in the slurry is 5 g / L, and the sodium hydroxide concentration in the slurry is 70 g / L, then raising the temperature of the reactor to 65°C and reacting for 6 hours. During the reaction, sodium sulfide and sodium hydroxide are added to the slurry to control the sodium sulfide concentration in the slurry to 5 g / L and the sodium hydroxide concentration in the slurry to 70 g / L. After the reaction is completed, leachate and leach residue are obtained by solid-liquid separation, and the leach residue is successively recovered from the pyrometallurgical system and the rare earth recovery system to recover gold and silver ingots; wherein the molar ratio of sodium ascorbate to disodium edetate is 2:1, and the total amount of sodium ascorbate and disodium edetate is 1.5wt% of the total amount of the antimony-containing gold concentrate;

[0041] S2 The leachate obtained in step S1 is heated to 2.8 V at a cell voltage of 280 A / m 2 Electrolysis was carried out under the conditions of an electrode distance of 110 mm and an electrode deposition temperature of 75° C. After 5 days, the electrolysis was completed to obtain crude antimony and lean solution. The lean solution was recovered with sodium sulfide through an evaporative cooling system, and the mother liquor was returned to step S1. Example 3

[0042] A comprehensive recovery method for antimony-containing gold concentrate, wherein:

[0043] The main components of the antimony-bearing gold concentrate are: Au content 52.31g / t, Ag content 14.36g / t, Sb content 10.68wt%, S content 17.28wt%, and Zn content 0.21wt%.

[0044] The steps are as follows:

[0045] S1: adding antimony-containing gold concentrate to a reactor, then adding sodium ascorbate and disodium edetate to the reactor, slurrying with water, then adding sodium sulfide and sodium hydroxide to obtain a slurry, so that the solid-liquid mass ratio in the slurry is 1:4, the sodium sulfide concentration in the slurry is 10 g / L, and the sodium hydroxide concentration in the slurry is 50 g / L, then raising the temperature of the reactor to 40°C and reacting for 8 hours. During the reaction, sodium sulfide and sodium hydroxide are added to the slurry to control the sodium sulfide concentration in the slurry to 10 g / L and the sodium hydroxide concentration in the slurry to 50 g / L. After the reaction is completed, leachate and leach residue are obtained by solid-liquid separation, and the leach residue is successively recovered from the pyrometallurgical system and the rare earth recovery system to recover gold and silver ingots; wherein the molar ratio of sodium ascorbate to disodium edetate is 1.5:1, and the total amount of sodium ascorbate and disodium edetate is 0.5wt% of the total amount of the antimony-containing gold concentrate;

[0046] S2 The leachate obtained in step S1 is heated to 3.0 V at a cell voltage of 3.0 V and a current density of 300 A / m 2 Electrolysis was carried out under the conditions of an electrode distance of 110 mm and an electrode deposition temperature of 80° C. After 4.5 days, the electrolysis was completed to obtain crude antimony and lean solution. The lean solution was recovered with sodium sulfide through an evaporative cooling system, and the mother liquor was returned to step S1. Comparative Example 1

[0047] Refer to Example 1, except that: in step S1, sodium ascorbate is not added. Comparative Example 2

[0048] Refer to Example 1, except that: in step S1, disodium edetate is not added. Comparative Example 3

[0049] Refer to Example 1, except that: in step S1, no antioxidant is added.

[0050] test

[0051] The Au content in the leachate obtained in step S1 of Examples 1 to 3 and Comparative Examples 1 to 3 and the crude antimony obtained in step S2 was detected, and the results are shown in Table 1. The recovery rate of each valuable element in Examples 1 to 3 and Comparative Examples 1 to 3 was calculated, and the results are shown in Table 2.

[0052] The gold content in the leachate is tested with reference to the "Chemical Analysis Methods for Precious Metal Alloy Electroplating Wastewater Part 1: Determination of Gold, Silver, Platinum, Palladium and Iridium Contents - Inductively Coupled Plasma Atomic Emission Spectrometry (GB / T 43753.1-2024)". The gold content in crude antimony is tested with reference to the "Chemical Analysis Methods for Crude Antimony Part 2: Determination of Gold Content - Fire Assay Gravimetric Method (YS / T1582.2-2022)".

[0053] Table 1 Au content in leachate and crude antimony

[0054] Au content Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Leachate mg / L 0.19 0.48 0.26 1.01 1.21 1.62 Crude antimony g / t 2.94 7.43 4.01 15.68 18.80 25.21

[0055] Table 2 Recovery rate of valuable elements

[0056] Recovery rate (%) Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Au 97.58 97.64 97.18 89.25 89.05 84.98 Sb 95.25 95.57 95.67 95.12 95.67 95.37

[0057] As shown in Tables 1 and 2, by adopting the technical solution of the present invention (Examples 1 to 3), Au in the leachate is ≤0.5 mg / L, and Au in the crude antimony is ≤10 g / t; the Au recovery rate is more than 97%, and the Sb recovery rate is more than 95%; in Comparative Examples 1 and 2, the gold content in the leachate is 1.01 mg / L and 1.21 mg / L, respectively, the gold content in the crude antimony is 15.68 g / t and 18.80 g / t, respectively, and the Au recovery rates are 89.25% and 89.05%, respectively; in Comparative Example 3, the gold content in the leachate is 1.62 mg / L, the gold content in the crude antimony is 25.21 g / t, and the Au recovery rate is 84.98%; this indicates that although the addition of sodium ascorbate or disodium edetate alone during alkaline leaching can reduce gold loss to a certain extent, the addition of the antioxidant of the present invention has a better effect, can effectively inhibit gold leaching, reduce gold loss, and improve gold recovery.

[0058] 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 comprehensive recovery method for antimony-containing gold concentrate, characterized in that: The steps include: S1: mixing and slurrying the antimony-containing gold concentrate and the antioxidant, then adding sodium sulfide and sodium hydroxide to obtain a slurry, and obtaining a leachate and a leach residue after reaction; S2. Electrolytically depositing the leaching solution obtained in step S1 to obtain crude antimony and lean solution; Wherein, in step S1, the antioxidant is a mixture of sodium ascorbate and disodium edetate, and the molar ratio of sodium ascorbate to disodium edetate is (1-2):1; in step S1, the total amount of the antioxidant is 0.5wt%-2.5wt% of the total amount of the antimony-containing gold concentrate; in step S1, the solid-liquid mass ratio in the slurry is 1:(2-4); in step S1, the sodium sulfide concentration in the slurry is 5-20g / L, and the sodium hydroxide concentration in the slurry is 50-100g / L.

2. The method according to claim 1, characterized in that In step S1, sodium sulfide and sodium hydroxide are added to the slurry during the reaction process, and the concentration of sodium sulfide in the slurry is controlled to be 5-20 g / L, and the concentration of sodium hydroxide in the slurry is controlled to be 50-100 g / L.

3. The method according to claim 1, characterized in that In step S1, the reaction temperature is 40-95° C., and the reaction time is 4-8 h.

4. The method according to claim 1, wherein In step S1, the leached residue is sequentially passed through a pyrometallurgical smelting system and a rare earth recovery system to recover gold and silver.

5. The method according to claim 1, wherein In step S2, the electrolytic operation is as follows: the cell voltage is 2.5-3.0V, the current density is 250-300A / m 2 , the electrode distance is 110mm, the electrodeposition temperature is 70~80℃, and the electrodeposition time is 4~5 days.

6. The method according to claim 1, characterized in that In step S2, the lean liquid is subjected to an evaporative cooling system to recover sodium sulfide, and the obtained mother liquor is returned to step S1.

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