Method for obtaining sodium antimonate product based on two-stage cyclic leaching
Through the double-stage cyclic leaching method, the formation of gold and polysulfide complexes is suppressed, and the gold in sodium antimonate is efficiently recovered, which solves the problem of gold loss in sodium antimonate production and improves the quality and environmental friendliness of sodium antimonate.
Patent Information
- Application Number
- CN202510910678.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-02
- Publication Date
- 2025-10-14
AI Technical Summary
In the existing technology, the gold element is seriously lost during the production of sodium antimonate, resulting in waste of resources and economic losses. In addition, the traditional process has environmental pollution and difficulty in wastewater treatment. The gold inhibition rate is not high, which affects the antimony leaching rate and quality.
A two-stage cyclic leaching method is adopted, including primary sulfide leaching, two-stage leaching and cyclic sulfide leaching, combined with the antimony oxidation precipitation step. By controlling parameters such as temperature, liquid-solid ratio and alkalinity, the formation of gold and polysulfide complexes is suppressed to achieve efficient gold recovery.
It effectively inhibits gold leaching, with a gold recovery rate of up to 99.6%. The gold content in the sodium antimonate product is reduced to less than 0.5g/t, which improves the quality of the sodium antimonate and reduces the difficulty of wastewater treatment, achieving economical and environmentally friendly gold recovery.
Smart Images
Figure CN120776140A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of rare and precious metal recovery in non-ferrous smelting, and more particularly to a method for obtaining a sodium antimonate product based on double-stage circulation leaching. Background Art
[0002] Sodium antimonate is an important inorganic chemical product widely used in flame retardants, catalysts, glass clarifiers, and other fields. In the nonferrous metallurgical industry, the raw materials for sodium antimonate production primarily come from the complex, low-concentration antimony-containing materials left after gold and silver are extracted during copper smelting. In traditional processes, some gold enters the sodium antimonate production system and is directly lost with the finished product, resulting in significant resource waste and economic losses.
[0003] At present, the production of sodium antimonate from complex antimony-containing materials mainly adopts a wet process, including sulfidation leaching, oxidation precipitation of antimony and other steps. For example, Chinese Patent Document 1 (Application No.: 202411701729.1, Application Date: 2024.11.26) discloses a method for improving the recovery rate of silver and copper by wet leaching of antimony high-salt waste liquid, comprising the following steps: (1) blending of the first-level silver-copper-gold concentrate: blending the silver-copper-gold concentrate; (2) producing the second-level high-salt waste liquid: slurrying the antimony-containing ore with water to a ore concentration of 40-50w%, using sodium hydroxide and sodium sulfide for stirring and leaching to obtain an antimony-containing liquid, the antimony-containing liquid is subjected to high-temperature oxidation treatment to obtain an antimony-containing precipitate and a high-salt waste liquid, and the antimony-containing precipitate is washed and dried to produce sodium pyroantimonate. After the low-concentration antimony-containing material is sulfided and leached, an oxidant is added to generate sodium pyroantimonate. During the leaching process, gold easily reacts with sulfide or polysulfide to form a soluble complex, which is lost with the antimony leachate.
[0004] In the prior art, the separation of gold and antimony mainly relies on pyrolysis or wet processing, but the pyrolysis process is highly environmentally polluting, and the wet process has problems such as long process and high difficulty in wastewater treatment. There are also technical attempts to reduce gold leaching through inhibitors (such as manganese powder and iron powder). For example, Chinese Patent Document 2 (Application Number: 202210630596.8, Application Date: 2022.06.06) discloses a method for inhibiting gold leaching during alkaline leaching of antimony from antimony-containing gold concentrate, comprising the following steps: Step 1, adding an inhibitor to an alkaline solution containing hydroxide, stirring and dissolving, and then adding sodium sulfide to obtain a leachate; the dissolution temperature is controlled at 40°C to 95°C; wherein The inhibitor is one or more of manganese powder, iron powder, and reduced carbon powder. Second, powdered antimony-containing gold concentrate is added to the leachate, stirred at a constant temperature, and reacted for 5 to 120 minutes. The inhibitor dosage is 0.5% to 5.0% of the amount of the powdered antimony-containing gold concentrate. Third, the slurry after the reaction is subjected to solid-liquid separation to obtain an antimony-containing filtrate and gold-rich antimony-removed slag. The antimony-removed slag is washed and air-dried and then used as a raw material for gold smelting. The antimony-containing filtrate is purified and used as a raw material for antimony electrodeposition. However, this method has a low inhibition rate for gold and has a certain impact on the antimony leaching rate and the quality of the sodium antimonate product.
[0005] In summary, there is an urgent need for a technical method that has a high recovery rate for precious metal gold, does not affect the antimony leaching rate and quality, and is economical and environmentally friendly, so as to reduce the gold content in sodium antimonate products and achieve efficient recovery of gold elements. Summary of the Invention
[0006] In view of this, the present invention provides a method for recovering gold from complex antimony-containing materials based on double-stage cyclic leaching to obtain sodium antimonate products, while achieving efficient recovery of gold.
[0007] The present application provides a method for obtaining a sodium antimonate product based on a two-stage cyclic leaching process, comprising the following steps:
[0008] Primary sulfidation leaching: adding a sulfiding agent to an antimony-containing material I under alkaline conditions, and performing primary sulfidation leaching at 60° C.-100° C. for 1 hour-3 hours to obtain an antimony leaching solution I and an antimony leaching slag I; the sulfiding agent is selected from at least one of sodium sulfide and sodium hydrosulfide; and the amount of the sulfiding agent added is 1.3 to 2.5 times the equivalent of the antimony-containing material I;
[0009] Double-stage leaching: slurrying the antimony-containing material II under alkaline conditions to obtain a slurry, wherein the alkalinity of the slurry is 25 g / L-60 g / L, mixing the slurry with the antimony leaching solution I, and double-stage leaching at a temperature of 60° C.-100° C. for 1 h-3 h to obtain a double-stage antimony leaching solution and a double-stage antimony leaching slag; wherein the amount of the antimony-containing material II added is 0.5 to 1.2 times the equivalent of the antimony-containing material I in the primary sulfidation leaching; and the liquid-to-solid ratio during the double-stage leaching process is 6:1 mL / g to 10:1 mL / g;
[0010] Circulating sulfidation leaching: adding a sulfiding agent to the double-stage antimony leaching slag under alkaline conditions and performing cyclic sulfidation leaching to obtain antimony leaching slag II and antimony leaching solution II. The antimony leaching slag II is fed into a gold recovery system, and the antimony leaching solution II is returned to the double-stage leaching for double-stage leaching. The amount of the sulfiding agent added is 1.2 to 2.1 times the equivalent of the double-stage antimony leaching slag. The temperature of the cyclic sulfidation leaching is 80° C. to 95° C., and the time of the cyclic sulfidation leaching is 1 to 3 hours.
[0011] Antimony precipitation by oxidation: The two-stage antimony leaching solution is mixed with an oxidant to undergo an oxidation reaction to obtain a sodium antimonate product. The oxidant is selected from at least one of hydrogen peroxide, oxygen, and potassium permanganate, and the amount of the oxidant used is 1.2 to 1.5 equivalents of the theoretical reaction amount of antimony. The oxidation reaction temperature is 100° C. to 140° C., the oxidation reaction time is 4 to 10 hours, and the oxidation reaction pressure is 0.8 MPa to 2 MPa.
[0012] Optionally, the alkalinity of the slurry is independently selected from any value among 25 g / L, 40 g / L, 60 g / L, or any range of values between any two of the above points.
[0013] Optionally, in the primary sulfidation leaching, the amount of sulfiding agent added is independently selected from any value among 1.3 times the equivalent, 1.5 times the equivalent, 1.8 times the equivalent, 2.1 times the equivalent, 2.5 times the equivalent of the antimony-containing material I, or any range of values between any two of the above points.
[0014] Optionally, in the double-stage leaching, the amount of antimony-containing material II added is independently selected from any value among 0.5 times the equivalent, 0.8 times the equivalent, 1 times the equivalent, 1.2 times the equivalent of the antimony-containing material I in the primary sulfide leaching, or any range of values between any two of the above points.
[0015] Optionally, during the double-stage leaching process, the liquid-to-solid ratio is independently selected from any value among 6:1 mL / g, 8:1 mL / g, 10:1 mL / g, or any range of values between any two of the above points.
[0016] Optionally, in the cyclic sulfidation leaching, the amount of the sulfiding agent added is independently selected from any value among 1.2 times the equivalent, 1.5 times the equivalent, 1.8 times the equivalent, 2.1 times the equivalent of the double-stage antimony leaching slag, or any range of values between any two of the above points.
[0017] Optionally, the temperature of the cyclic sulfidation leaching is independently selected from any value among 80°C, 90°C, 95°C or any range of values between any two of the above points.
[0018] Optionally, the temperature of the oxidation reaction is independently selected from any value among 100°C, 110°C, 120°C, 130°C, 140°C or any range between any two of the above points.
[0019] Optionally, the antimony-containing material I and the antimony-containing material II are antimony-containing materials obtained by extracting gold and silver and then removing copper and bismuth during the copper smelting process.
[0020] Optionally, the temperature of the primary sulfidation leaching is 80°C-95°C.
[0021] Optionally, the temperature of the primary sulfidation leaching is independently selected from any value among 60°C, 70°C, 80°C, 90°C, 95°C, 100°C or any range of values between any two of the above points.
[0022] Optionally, during the primary sulfidation leaching process, the liquid-to-solid ratio is 6:1 mL / g-10:1 mL / g and the free alkalinity is 25 g / L-60 g / L.
[0023] Optionally, during the primary sulfidation leaching process, the liquid-to-solid ratio is independently selected from any value among 6:1 mL / g, 8:1 mL / g, 10:1 mL / g, or any range of values between any two of the above points.
[0024] Optionally, during the primary sulfidation leaching process, the free alkalinity is independently selected from any value among 25 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, or any range of values between any two of the above points.
[0025] Optionally, the temperature of the double-stage leaching is 80°C-95°C.
[0026] Optionally, the temperature of the double-stage leaching is independently selected from any value among 60°C, 70°C, 80°C, 90°C, 95°C, 100°C or any range of values between any two of the above points.
[0027] Optionally, during the cyclic sulfide leaching process, the liquid-to-solid ratio is 6:1 mL / g-10:1 mL / g, and the free alkalinity is 25 g / L-60 g / L.
[0028] Optionally, during the cyclic sulfide leaching process, the liquid-to-solid ratio is independently selected from any value of 6:1 mL / g, 7:1 mL / g, 8:1 mL / g, 9:1 mL / g, 10:1 mL / g, or any range of values between any two of the above points.
[0029] Optionally, during the cyclic sulfide leaching process, the free alkalinity is independently selected from any value among 25 g / L, 30 g / L, 40 g / L, 45 g / L, 60 g / L or any range of values between any two of the above points.
[0030] Optionally, the pressure of the oxidation reaction is 0.9 MPa-1.5 MPa.
[0031] Optionally, the pressure of the oxidation reaction is independently selected from any value among 0.8 MPa, 0.9 MPa, 1.2 MPa, 1.5 MPa, 2 MPa, or any range of values between any two of the above points.
[0032] The method of the present invention must be carried out strictly in accordance with the above-mentioned steps, and the process sequence cannot be changed arbitrarily.
[0033] Compared with the prior art, the method for obtaining a sodium antimonate product based on a two-stage cyclic leaching provided by the present invention achieves at least the following beneficial effects:
[0034] First, the use of a two-stage cyclic leaching method can effectively inhibit the formation of gold-polysulfide complexes. The gold-sulfur complexation reaction proceeds in reverse, thereby achieving the purpose of inhibiting gold leaching. The process is economical and environmentally friendly, does not require the addition of complex inhibitors, and reduces the difficulty of wastewater treatment.
[0035] Second, compared with the traditional direct leaching process, the gold content of the sodium antimonate product produced by this method can be reduced to less than 0.5g / t, and the quality of sodium antimonate is significantly improved;
[0036] Third, the method can be used to enrich the gold in the antimony leaching solution and the double-stage antimony leaching solution in the antimony leaching residue, thereby preventing the gold from entering the sodium antimonate product through the antimony oxidation precipitation process, and the gold recovery rate is as high as 99.6%.
[0037] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.
[0038] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0040] Figure 1 The present invention is a flow chart of a method for obtaining a sodium antimonate product based on double-stage circulation leaching. DETAILED DESCRIPTION
[0041] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention.
[0042] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.
[0043] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.
[0044] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.
[0045] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.
[0046] Reference Figure 1 , Figure 1 The present invention is a flow chart of a method for obtaining a sodium antimonate product based on a double-stage cyclic leaching process, which specifically includes the following steps:
[0047] S1. Primary sulfidation leaching: Add a sulfiding agent to the complex antimony-containing material under alkaline conditions and leach under heating conditions to obtain an antimony leaching solution and an antimony leaching residue;
[0048] S2. Double-stage leaching: The antimony leaching solution and the complex antimony-containing material are mixed in proportion and leached under heating conditions to obtain a double-stage antimony leaching solution and a double-stage antimony leaching slag;
[0049] S3, cyclic sulfide leaching: the double-stage antimony leaching slag is returned to S1 for a sulfide leaching, the obtained antimony leaching slag is sent to the gold recovery system, and the antimony leaching solution is then sent to S2 for double-stage leaching;
[0050] S4. Antimony precipitation by oxidation: The double-stage antimony leaching solution is mixed with an oxidant and subjected to a high-temperature oxidation reaction to obtain sodium antimonate product.
[0051] Furthermore, the complex antimony-containing material in step S1 is an antimony-containing material obtained by extracting gold and silver and then removing copper and bismuth during the copper smelting process;
[0052] The sulfiding agent in step S1 is one or more of sodium sulfide and sodium hydrosulfide; the temperature is 60°C-100°C, preferably 80°C-95°C;
[0053] The amount of the sulfiding agent added is 1.3-2.5 times the equivalent of the antimony-containing material, the liquid-solid ratio during the leaching process is 6:1 mL / g-10:1 mL / g, the free alkalinity is between 25 g / L-60 g / L, and the leaching time is 1 h-3 h.
[0054] Specifically, step S1 is a primary sulfidation leaching, which first converts the antimony element in the antimony-containing material into sodium thioantimonate with sulfur and then leaches it into a solution, thereby achieving preliminary separation and recovery of the antimony element.
[0055] Furthermore, in the double-stage leaching process of step S2, the complex antimony-containing material is first slurried under alkaline conditions before mixing, and the alkalinity of the slurry is controlled to be 25 g / L-60 g / L;
[0056] The temperature is 60°C-100°C, preferably 80-95°C;
[0057] The amount of the complex antimony-containing material added is 0.5-1.2 times the equivalent of the antimony-containing material in step S1, the liquid-solid ratio of the double-stage leaching process is 6:1 mL / g-10:1 mL / g, and the leaching time is 1 h-3 h.
[0058] It should be noted that the excess sulfiding reagent in step S1 will react with the gold in the antimony-containing material to form a gold-sulfur complex to form a soluble complex, which will be lost with the antimony leaching solution, resulting in the loss of gold and the final sodium antimonate product being rich in gold. The present application uses a two-stage circulating leaching method to consume the excess sulfiding reagent in the antimony leaching solution, thereby destroying the gold-sulfur complex reaction, prompting the gold in the antimony leaching solution to be redeposited into the antimony leaching slag, effectively inhibiting the formation of gold and polysulfide complexes, and the gold-sulfur complex reaction proceeds in reverse, thereby achieving the purpose of inhibiting gold leaching.
[0059] Furthermore, the specific process of step S3 is: returning the double-stage antimony leaching slag to the primary sulfidation leaching tank, and controlling the amount of sulfidation reagent added to be 1.2-2.1 times the equivalent of the double-stage antimony leaching slag;
[0060] The leaching temperature is 80℃-95℃, and the leaching time is 1h-3h;
[0061] The liquid-to-solid ratio during the leaching process is 6:1 mL / g-10:1 mL / g, and the free alkalinity during the leaching process is controlled to be 25 g / L-60 g / L.
[0062] It should be noted that after the double-stage leaching, some antimony will still exist in the double-stage antimony leaching slag. In step S3, the double-stage antimony leaching slag is subjected to sulfidation leaching again to improve the total leaching rate of antimony.
[0063] Furthermore, in step S4, the antimony precipitation process is carried out in a high-pressure reactor at a reaction pressure of 0.8 MPa-2 MPa, preferably 0.9 MPa-1.5 MPa;
[0064] The oxidant is one or more of hydrogen peroxide, oxygen, and potassium permanganate;
[0065] The amount of the oxidant used is 1.2-1.5 times the theoretical reaction amount of antimony;
[0066] The high-temperature oxidation reaction temperature is 100° C.-140° C., and the reaction time is 4 h-10 h.
[0067] It should be noted that the double-stage antimony leaching solution mainly contains sodium thioantimonate, which reacts with an oxidant, is oxidized and precipitated under specific reaction conditions to produce sodium antimonate products, thereby completing the recovery and conversion of antimony.
[0068] In the prior art, complex antimony-containing materials are recovered by direct leaching, and the specific steps include:
[0069] (1) Primary sulfidation leaching: Add a sulfiding agent to the complex antimony-containing material under alkaline conditions and leach it under heating conditions to obtain antimony leaching solution and antimony leaching residue;
[0070] (2) Antimony precipitation by oxidation: The antimony leaching solution is mixed with an oxidant and subjected to a high-temperature oxidation reaction to obtain sodium antimonate product.
[0071] In order to more intuitively compare the direct leaching method in the prior art and the method for obtaining a sodium antimonate product based on two-stage cyclic leaching in the present application, in this embodiment, the parameters of step (1) and step (2) in the direct leaching method are the same as the parameters of step S1 and step S4 in the method for obtaining a sodium antimonate product based on two-stage cyclic leaching in the corresponding embodiment, that is, the direct leaching method is equivalent to step S1 and step S4 in the method of the present application.
[0072] Example 1
[0073] A method for recovering gold from complex antimony-containing materials based on a two-stage cyclic leaching process comprises the following steps:
[0074] S1. Primary sulfide leaching: 320 g of wet slag of complex antimony-containing material, containing 21.8% water and 34.25% antimony, was slurried with 300 mL of water, 30 g of caustic soda flakes, 680 mL of 32% sodium hydrosulfide were added, and water was added to the solution to control the final liquid volume to 1.5 L. The liquid-to-solid ratio during the leaching process was controlled to be 6:1 mg / L, and the free alkalinity was 25 g / L. The mixture was heated to 95°C and leached for 1.5 h to obtain antimony leaching solution and antimony leaching slag.
[0075] S2, double-stage leaching: take another 320g of complex antimony-containing material, add 300mL of water to slurry, add 10g of caustic soda, and the slurry alkalinity is 25g / L; then add the antimony leaching solution obtained in step S1, add water to control the leaching liquid-solid ratio to 6:1mL / g, heat to 95℃ and leach for 1.5h to obtain a double-stage antimony leaching solution and double-stage antimony leaching slag;
[0076] S3, cyclic sulfidation leaching: 198.37g of the double-stage antimony leaching slag obtained in step S2 was slurried with 300mL of water, 30g of caustic soda was added, and the mixture was returned to the sulfidation leaching tank for leaching. The amount of 32% sodium hydrosulfide added was 1.5 times the equivalent of the double-stage antimony leaching slag, and the free alkalinity was controlled to be 25g / L. The mixture was heated to 95°C and leached for 1.5h. The obtained antimony leaching slag was fed into the gold recovery system, and the obtained antimony leaching solution was subjected to the double-stage leaching of step S2 again.
[0077] S4. Antimony precipitation by oxidation: The entire double-stage antimony leaching solution was introduced into a reactor, oxygen was introduced into the reactor, the reaction pressure was controlled at 1.2 MPa, the reaction temperature was maintained at 120° C., and the high-temperature oxidation reaction was carried out for 6 h to obtain 80.56 g of sodium antimonate product (containing 20% water). The gold content of the sodium antimonate product is shown in Table 1, and the gold recovery rate reached 99.83%.
[0078] Table 1 Gold content of sodium antimonate products produced by direct leaching and double-stage circulation leaching
[0079] Gold content (g / t) Raw materials (antimony-containing materials) Product (sodium antimonate) direct leaching method 30.86 48.97 Two-stage cyclic leaching method 30.86 0.206
[0080] Example 2
[0081] A method for recovering gold from complex antimony-containing materials based on a two-stage cyclic leaching process comprises the following steps:
[0082] S1. Primary sulfide leaching: 320 g of wet slag of complex antimony-containing material, containing 21.8% water and 34.25% antimony, was slurried with 300 mL of water, 60 g of caustic soda flakes, and 680 mL of 32% sodium hydrosulfide were added, and water was added to the solution to control the final liquid volume to 2 L. The liquid-solid ratio during the leaching process was controlled to be 8:1 mg / L, and the free alkalinity was 40 g / L. The mixture was heated to 90 ° C and leached for 1.5 h to obtain antimony leaching solution and antimony leaching slag;
[0083] S2, double-stage leaching: take another 240g of complex antimony-containing material, add 300mL of water to slurry, add 15g of caustic soda, and the slurry alkalinity is 40g / L; then add the antimony leaching solution obtained in step S1, add water to control the leaching liquid-solid ratio to 8:1mL / g, heat to 95℃ and leach for 1.5h to obtain a double-stage antimony leaching solution and double-stage antimony leaching slag;
[0084] S3, cyclic sulfidation leaching: 108g of the double-stage antimony leaching slag obtained in step S2 was slurried with 300mL of water, 60g of caustic soda was added, and the mixture was returned to the sulfidation leaching tank for leaching. The amount of 32% sodium hydrosulfide added was 1.2 times the equivalent of the double-stage antimony leaching slag, and the free alkalinity was controlled to 40g / L. The mixture was heated to 90°C and leached for 1.5h. The obtained antimony leaching slag was fed into the gold recovery system, and the obtained antimony leaching solution was subjected to the double-stage leaching of step S2 again.
[0085] S4. Antimony precipitation by oxidation: The entire double-stage antimony leaching solution was introduced into the reactor, oxygen was introduced into the reactor, the reaction pressure was controlled at 2 MPa, the reaction temperature was maintained at 100° C., and the high-temperature oxidation reaction was carried out for 4 h to obtain 80.12 g of sodium antimonate product (containing 22% water). The gold content of the sodium antimonate product is shown in Table 2, and the gold recovery rate reached 99.74%.
[0086] Table 2 Gold content of sodium antimonate products from direct leaching and double-stage circulation leaching
[0087] Gold content (g / t) Raw materials (antimony-containing materials) Product (sodium antimonate) direct leaching method 30.86 28.45 Two-stage cyclic leaching method 30.86 0.315
[0088] Example 3
[0089] A method for recovering gold from complex antimony-containing materials based on a two-stage cyclic leaching process comprises the following steps:
[0090] S1. Primary sulfide leaching: 320 g of wet slag of complex antimony-containing material, containing 21.8% water and 34.25% antimony, was slurried with 300 mL of water, 160 g of caustic soda flakes, 800 mL of 32% sodium hydrosulfide were added, and water was added to the solution to control the final liquid volume to 2.5 L. The liquid-to-solid ratio during the leaching process was controlled to be 10:1 mg / L, and the free alkalinity was 60 g / L. The mixture was heated to 90 ° C and leached for 1.5 h to obtain antimony leaching solution and antimony leaching slag;
[0091] S2, double-stage leaching: take another 384g of complex antimony-containing material, add 300mL of water to slurry, add 20g of caustic soda, and the slurry alkalinity is 60g / L; then add the antimony leaching solution obtained in step S1, add water to control the leaching liquid-solid ratio to 10:1mL / g, heat to 80℃ and leach for 3h to obtain a double-stage antimony leaching solution and double-stage antimony leaching slag;
[0092] S3, cyclic sulfidation leaching: 172.80g of the double-stage antimony leaching slag obtained in step S2 was slurried with 300mL of water, 60g of caustic soda was added, and the mixture was returned to the sulfidation leaching tank for leaching. The amount of 32% sodium hydrosulfide added was 2.1 times the equivalent of the double-stage antimony leaching slag, and the free alkalinity was controlled to be 60g / L. The mixture was heated to 90°C and leached for 1.5h. The obtained antimony leaching slag was fed into the gold recovery system, and the obtained antimony leaching solution was subjected to the double-stage leaching of step S2 again.
[0093] S4. Antimony precipitation by oxidation: The entire double-stage antimony leaching solution was introduced into a reactor, oxygen was introduced into the reactor, the reaction pressure was controlled at 0.8 MPa, the reaction temperature was 140° C., and the high-temperature oxidation reaction was carried out for 10 h to obtain 80.33 g of sodium antimonate product (containing 21.2% water). The gold content of the sodium antimonate product is shown in Table 2, and the gold recovery rate reached 99.68%.
[0094] Table 3 Gold content of sodium antimonate products from direct leaching and double-stage circulation leaching
[0095] Gold content (g / t) Raw materials (antimony-containing materials) Product (sodium antimonate) direct leaching method 30.86 35.16 Two-stage cyclic leaching method 30.86 0.395
[0096] Example 4
[0097] A method for recovering gold from complex antimony-containing materials based on a two-stage cyclic leaching process comprises the following steps:
[0098] S1. Primary sulfidation leaching: 320 g of wet slag of complex antimony-containing material, containing 21.8% water and 34.25% antimony, was slurried with 300 mL of water, 30 g of caustic soda flakes, and 250.36 g of sodium sulfide were added, and water was added to the solution to control the final liquid volume to 1.5 L. The liquid-to-solid ratio during the leaching process was controlled to be 6:1 mg / L, and the free alkalinity was 25 g / L. The mixture was heated to 95°C and leached for 1.5 h to obtain antimony leaching solution and antimony leaching slag.
[0099] S2, double-stage leaching: take another 320g of complex antimony-containing material, add 300mL of water to slurry, add 10g of caustic soda, and the slurry alkalinity is 25g / L; then add the antimony leaching solution obtained in step S1, add water to control the leaching liquid-solid ratio to 6:1mL / g, heat to 95℃ and leach for 1.5h to obtain a double-stage antimony leaching solution and double-stage antimony leaching slag;
[0100] S3, circulating sulfide leaching: 190.26g of the double-stage antimony leaching slag obtained in step S2 was slurried with 300mL of water, 30g of caustic soda was added, and the mixture was returned to the sulfide leaching tank for leaching. The amount of sodium sulfide added was 1.5 times the equivalent of the double-stage antimony leaching slag, and the free alkalinity was controlled to 25g / L. The mixture was heated to 95°C and leached for 1.5h. The obtained antimony leaching slag was fed to a gold recovery system, and the obtained antimony leaching solution was subjected to the double-stage leaching of step S2 again. S4, antimony precipitation by oxidation: the entire double-stage antimony leaching solution was passed into a reactor, hydrogen peroxide was added to the reactor, the reaction pressure was controlled to 1.2MPa, the reaction temperature was 120°C, and a high-temperature oxidation reaction was carried out for 6h to obtain 83.21g of sodium antimonate product (containing 26% water). The gold content of the sodium antimonate product is shown in Table 1, and the gold recovery rate reaches 99.63%.
[0101] Table 4 Gold content of sodium antimonate products produced by direct leaching and double-stage circulation leaching
[0102] Gold content (g / t) Raw materials (antimony-containing materials) Product (sodium antimonate) direct leaching method 30.86 40.25 Two-stage cyclic leaching method 30.86 0.458
[0103] It can be seen from the above examples that the method for obtaining a sodium antimonate product based on a two-stage cyclic leaching provided by the present invention achieves at least the following beneficial effects:
[0104] 1. The double-stage cyclic leaching method can effectively inhibit the formation of gold-polysulfide complexes. The gold-sulfur complexation reaction proceeds in reverse, thereby achieving the purpose of inhibiting gold leaching. The process is economical and environmentally friendly, does not require the addition of complex inhibitors, and reduces the difficulty of wastewater treatment.
[0105] 2. In Example 1, the gold content of the sodium antimonate product obtained by the double-stage circulation leaching method is 0.206 g / t; in Example 2, the gold content of the sodium antimonate product obtained by the double-stage circulation leaching method is 0.315 g / t; in Example 3, the gold content of the sodium antimonate product obtained by the double-stage circulation leaching method is 0.395 g / t; in Example 4, the gold content of the sodium antimonate product obtained by the double-stage circulation leaching method is 0.458 g / t. Compared with the traditional direct leaching process, the gold content of the sodium antimonate product produced by this method can be reduced to within 0.5 g / t, and the quality of sodium antimonate is significantly improved;
[0106] 3. In Example 1, the gold recovery rate was 99.83%; in Example 2, the gold recovery rate was 99.74%; in Example 3, the gold recovery rate was 99.68%; and in Example 4, the gold recovery rate was 99.63%. The present method can enrich the gold in the antimony leaching solution and the double-stage antimony leaching solution in the antimony leaching slag, thereby preventing the gold from entering the sodium antimonate product through the antimony oxidation precipitation process. The gold recovery rate is as high as 99.6%.
[0107] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.
Claims
1. A method for obtaining sodium antimonate product based on double-stage cycle leaching, characterized in that: The following steps are involved: Primary sulfidation leaching: adding a sulfiding agent to an antimony-containing material I under alkaline conditions, and performing primary sulfidation leaching at 60° C.-100° C. for 1 hour-3 hours to obtain an antimony leaching solution I and an antimony leaching slag I; the sulfiding agent is selected from at least one of sodium sulfide and sodium hydrosulfide; and the amount of the sulfiding agent added is 1.3 to 2.5 times the equivalent of the antimony-containing material I; Double-stage leaching: slurrying the antimony-containing material II under alkaline conditions to obtain a slurry, wherein the alkalinity of the slurry is 25 g / L-60 g / L, mixing the slurry with the antimony leaching solution I, and double-stage leaching at a temperature of 60° C.-100° C. for 1 h-3 h to obtain a double-stage antimony leaching solution and a double-stage antimony leaching slag; wherein the amount of the antimony-containing material II added is 0.5 to 1.2 times the equivalent of the antimony-containing material I in the primary sulfidation leaching; and the liquid-to-solid ratio during the double-stage leaching process is 6:1 mL / g to 10:1 mL / g; Circulating sulfidation leaching: adding a sulfiding agent to the double-stage antimony leaching slag under alkaline conditions and performing cyclic sulfidation leaching to obtain antimony leaching slag II and antimony leaching solution II. The antimony leaching slag II is fed into a gold recovery system, and the antimony leaching solution II is returned to the double-stage leaching for double-stage leaching. The amount of the sulfiding agent added is 1.2 to 2.1 times the equivalent of the double-stage antimony leaching slag. The temperature of the cyclic sulfidation leaching is 80° C. to 95° C., and the time of the cyclic sulfidation leaching is 1 to 3 hours. Antimony precipitation by oxidation: The two-stage antimony leaching solution is mixed with an oxidant to undergo an oxidation reaction to obtain a sodium antimonate product. The oxidant is selected from at least one of hydrogen peroxide, oxygen, and potassium permanganate, and the amount of the oxidant used is 1.2 to 1.5 equivalents of the theoretical reaction amount of antimony. The oxidation reaction temperature is 100° C. to 140° C., the oxidation reaction time is 4 to 10 hours, and the oxidation reaction pressure is 0.8 MPa to 2 MPa.
2. The method according to claim 1, characterized in that The antimony-containing material I and the antimony-containing material II are antimony-containing materials obtained by extracting gold and silver and then removing copper and bismuth during the copper smelting process.
3. The method according to claim 1, characterized in that The temperature of the primary sulfidation leaching is 80°C-95°C.
4. The method according to claim 1, wherein During the primary sulfidation leaching process, the liquid-to-solid ratio is 6:1 mL / g-10:1 mL / g; and the free alkalinity is 25 g / L-60 g / L.
5. The method according to claim 1, wherein The temperature of the double-stage leaching is 80°C-95°C.
6. The method according to claim 1, characterized in that During the cyclic sulfide leaching process, the liquid-to-solid ratio is 6:1 mL / g-10:1 mL / g, and the free alkalinity is 25 g / L-60 g / L.
7. The method according to claim 1, characterized in that The pressure of the oxidation reaction is 0.9 MPa-1.5 MPa.
Citation Information
Patent Citations
A method for inhibiting gold leaching during alkaline leaching of antimony-containing gold concentrate
CN114941078B
Method for improving silver and copper recovery rate by using wet antimony leaching high-salt waste liquid
CN119506584A