Process for extracting and purifying gold from oxidized gold ore
By using composite leaching and multi-step processing in low-grade oxidized gold ore, the problem of low recovery in the prior art is solved and a higher product gold yield is achieved.
Patent Information
- Application Number
- CN202411643616.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-03-25
AI Technical Summary
The prior art has low recovery rates when dealing with low-grade oxidized gold containing coarse-grained gold, usually only reach 60-70%, resulting in waste of valuable resources.
The composite leaching solution is used for heap leaching, which consists of a leaching agent, a surfactant, a stabilizer and an acid accelerator. Through the storage, adsorption, desorption and precipitation recovery steps, the extraction efficiency of gold is improved.
By increasing the dissolution rate and leaching efficiency of gold in gold ore, the yield of product gold is significantly improved, exceeding the recovery rate of traditional processes.
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of gold extraction from gold mines, and in particular to a process for extracting and purifying gold from oxidized gold mines. Background Art
[0002] In the current gold production, the treatment of low-grade oxidized ores containing gold mainly adopts heap leaching process and granulation heap leaching process. The former is suitable for ores with less mud content and good permeability, and the latter is suitable for ores with high mud content. It is to add a certain proportion of cement as a binder during the granulation process, and heap leaching is carried out after granulation solidification. Both belong to a single heap leaching process. The above two processes have the advantages of low ore dressing cost, but for low-grade oxidized ores containing coarse gold, no matter which of the two processes is used, the ideal recovery rate cannot be obtained, generally only reaching 60-70%, resulting in a waste of precious resources. Summary of the invention
[0003] In order to improve the yield of product gold, the present application provides a process for extracting and purifying gold from oxidized gold ore.
[0004] The present application provides a process for extracting and purifying gold from oxidized gold ore, which adopts the following technical solution: A process for extracting and purifying gold from an oxidized gold ore, comprising the following steps: Crushing: crushing the raw ore to obtain powder ore; Heap leaching: the powder ore is first piled up, and then heap leached with a composite leaching solution to obtain a leaching mixture; wherein the raw materials of the composite leaching solution include a leaching agent, a surfactant, a stabilizer, and an acid promoter, and the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1: (0.05-0.15): (0.05-0.10), and the pH of the composite leaching solution is 9-11; Adsorption: using an adsorbent to adsorb the leaching mixture to obtain a gold-loaded material; Desorption: desorbing the gold-loaded material to obtain a desorption solution; Precipitation recovery: Use a precipitant to precipitate and recover the desorption liquid to obtain the product gold.
[0005] By adopting the above technical scheme, the acid promoter can promote the dissolution of gold, the leaching agent improves the leaching efficiency of gold, the surfactant can effectively reduce the surface tension of the solution, improve the wettability of the gold mine surface, and thus enhance the dissolution rate of gold in the gold mine, and the stabilizer can effectively improve the stability of the composite leaching solution to ensure the stability of the leaching efficiency during the gold mine leaching process. Therefore, the composite leaching solution composed of the leaching agent, the surfactant, the stabilizer, and the acid promoter is used to improve the extraction effect of gold in the gold mine. Finally, the leaching mixture is adsorbed, desorbed, and precipitated for recovery, thereby improving the yield of the product gold.
[0006] In a specific embodiment, the leaching agent includes one of sodium cyanide and sodium carbonate.
[0007] By adopting the above technical solution, both sodium cyanide and sodium carbonate have good leaching effects, wherein the specific structure of sodium cyanide enables it to efficiently form a complex with gold, thereby achieving efficient leaching of gold.
[0008] In a specific embodiment, the surfactant includes one or more of alkyl polyoxyethylene ether, fatty alcohol polyoxyethylene ether, palmityl alcohol polyoxyethylene ether, and nonylphenol polyoxyethylene ether.
[0009] By adopting the above technical scheme, the long-chain alkyl part in the alkyl polyoxyethylene ether can reduce the surface tension of the mineral surface, making it easier for the leaching agent to penetrate into the ore, and the polyoxyethylene ether chain can increase the polarity of the solution. When combined with fatty alcohol polyoxyethylene ether, it can further promote the dissolution of the substance. Therefore, the combination of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether can further improve the yield of product gold.
[0010] In a specific embodiment, the acid promoter includes one of sulfuric acid, hydrochloric acid and nitric acid.
[0011] By adopting the above technical solution, sulfuric acid, hydrochloric acid and nitric acid all have a good promoting effect, among which the strong acidity of sulfuric acid can effectively dissolve the inclusions on the surface of the mineral and increase the chance of the leaching agent contacting with gold.
[0012] In a specific embodiment, the stabilizer comprises glucose.
[0013] By adopting the above technical solution, glucose chelates metal ions that may exist in the solution, thereby maintaining the stability of the solution and preventing the effective ingredients from being degraded or undergoing other adverse changes.
[0014] In a specific embodiment, in the ore crushing step, the particle size of the powder ore is 5-10 mm.
[0015] By adopting the above technical solution, the particle size of the powder ore is further limited, which facilitates better extraction of gold from the powder ore.
[0016] In a specific embodiment, in the heap leaching step, the mass concentration of the leaching agent in the composite leaching solution is 0.05-0.1%.
[0017] By adopting the above technical solution, the proportion of the leaching agent in the composite leaching solution is further limited, which can effectively dissolve the gold in the ore.
[0018] In a specific embodiment, the adsorbent includes activated carbon with a particle size of 0.3-0.5 mm.
[0019] In a specific embodiment, the desorption step is: desorbing the gold-loaded material using an acidic solution to obtain a desorption solution, and the acidic solution is a hydrochloric acid solution or a sodium hydroxide solution.
[0020] In a specific embodiment, the precipitant includes one of zinc powder, iron powder and aluminum powder.
[0021] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, the acid promoter can promote the dissolution of gold, the leaching agent improves the leaching efficiency of gold, the surfactant can effectively reduce the surface tension of the solution, improve the wettability of the gold mine surface, and thus enhance the dissolution rate of gold in the gold mine, and the stabilizer can effectively improve the stability of the composite leaching solution to ensure the stability of the leaching efficiency during the leaching process of the gold mine. Therefore, the composite leaching solution composed of the leaching agent, the surfactant, the stabilizer, and the acid promoter is used to improve the extraction effect of gold in the gold mine. Finally, the leaching mixture is adsorbed, desorbed, and precipitated for recovery, thereby improving the yield of the product gold; 2. The long-chain alkyl part in the alkyl polyoxyethylene ether in the present application can reduce the surface tension of the mineral surface, making it easier for the leaching agent to penetrate into the ore, and the polyoxyethylene ether chain can increase the polarity of the solution, and then cooperate with the fatty alcohol polyoxyethylene ether to further promote the dissolution of the substance. Therefore, the use of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether can further improve the yield of product gold; 3. In the present application, glucose maintains the stability of the solution by chelating metal ions that may be present in the solution, thereby preventing degradation or other adverse changes of the active ingredients. DETAILED DESCRIPTION
[0022] The present application is further described in detail below with reference to the embodiments.
[0023] All raw materials in the embodiment can be obtained commercially. The raw ore is the ore of Taibai Gold Mine; the surfactant includes but is not limited to a mixture of one or more of alkyl polyoxyethylene ether, fatty alcohol polyoxyethylene ether, palm alcohol polyoxyethylene ether, and nonylphenol polyoxyethylene ether, and in this application, it is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether; the acid promoter includes but is not limited to one of sulfuric acid, hydrochloric acid, and nitric acid, and sulfuric acid is preferred in this application; the precipitant includes but is not limited to one of zinc powder, iron powder, and aluminum powder, and zinc powder is preferred in this application. Example
[0024] Example 1 Example 1 provides a process for extracting and purifying gold from an oxidized gold ore, comprising the following steps: Crushing: crush the raw ore to obtain powder ore with a particle size of 5-10mm; Heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber is arranged between each layer of the stacking; the leaching agent, surfactant and stabilizer are stirred and mixed evenly, added to water, and then an acid promoter is added to adjust the pH of the solution to 9 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the weight ratio of the leaching agent, surfactant and stabilizer is 1:0.05:0.05; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; Adsorption: adding the adsorbent to the leaching mixture, stirring for adsorption, filtering, and obtaining the gold-loaded material; wherein the adsorbent is activated carbon with a particle size of 0.3-0.5 mm; Desorption: adding an acidic solution to the gold-loaded material, stirring for desorption, filtering, and obtaining a desorption solution, wherein the acidic solution is a hydrochloric acid solution; Precipitation recovery: pour the desorption liquid into a precipitation reactor, add a precipitant, react and precipitate, pour the desorption liquid into the precipitation reactor to obtain the product gold; the precipitant is zinc powder.
[0025] Example 2 The difference between Example 2 and Example 1 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent, surfactant, and stabilizer are stirred and mixed evenly, added to water, and then an acid promoter is added to adjust the pH of the solution to 10 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.05:0.05; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 1.
[0026] Example 3 The difference between Example 3 and Example 1 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent, surfactant, and stabilizer are stirred and mixed evenly, added to water, and then an acid promoter is added to adjust the pH of the solution to 11 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.05:0.05; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 1.
[0027] Example 4 The difference between Example 4 and Example 2 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent, surfactant, and stabilizer are stirred and mixed evenly, added to water, and then an acid promoter is added to adjust the pH of the solution to 10 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.1:0.08; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 2.
[0028] Example 5 The difference between Example 5 and Example 2 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent, surfactant, and stabilizer are stirred and mixed evenly, added to water, and then an acid promoter is added to adjust the pH of the solution to 10 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.15:0.10; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 2.
[0029] Example 6 The difference between Example 6 and Example 4 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent, surfactant, and stabilizer are stirred and mixed evenly, added to water, and then an acid promoter is added to adjust the pH of the solution to 10 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.08%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.1:0.08; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 4.
[0030] Example 7 The difference between Example 7 and Example 4 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber is arranged between each layer of the stacking; the leaching agent, surfactant, and stabilizer are stirred and mixed evenly, added to water, and then an acid promoter is added to adjust the pH of the solution to 10 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.1%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.1:0.08; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 4.
[0031] Example 8 The difference between Example 8 and Example 6 is that the surfactant is alkyl polyoxyethylene ether; the remaining steps are consistent with Example 6.
[0032] Example 9 The difference between Example 9 and Example 6 is that the surfactant is fatty alcohol polyoxyethylene ether; the remaining steps are consistent with Example 6.
[0033] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that, in the heap leaching, the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent is added to water to obtain a leaching solution; the leaching solution is sprayed on the stockpiled powder ore to perform heap leaching to obtain a leaching mixed solution; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the leaching agent is sodium cyanide; and the remaining steps are consistent with Example 1.
[0034] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent, the surfactant, and the stabilizer are stirred and mixed evenly, added to water, and then the acid promoter is added to adjust the pH of the solution to 8 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.05:0.05; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 1.
[0035] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the heap leaching: the powder ore is first piled up to form a multi-layer stacking structure, and a mesh isolation cloth made of bamboo fiber material is arranged between each layer of the stacking; the leaching agent, the surfactant, and the stabilizer are stirred and mixed evenly, added to water, and then the acid promoter is added to adjust the pH of the solution to 12 to obtain a composite leaching solution; the composite leaching solution is sprayed on the stockpiled powder ore for heap leaching to obtain a leaching mixture; wherein the mass concentration of the leaching agent in the composite leaching solution is 0.05%; the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1:0.05:0.05; the leaching agent is sodium cyanide; the surfactant is a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, and the weight ratio of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether is 1:1; the stabilizer is glucose; the acid promoter includes sulfuric acid with a mass concentration of 95%; and the remaining steps are consistent with Example 1.
[0036] Performance test yield: The yield of the product gold in each embodiment and comparative example is tested. The higher the yield, the higher the resource utilization rate of the original ore.
[0037] Table 1 Performance test results of product gold Combining Example 1 and Comparative Example 1, the yield of product gold in Example 1 is relatively high. It can be seen that the gold extraction process in the present application uses a composite leaching solution composed of a leaching agent, a surfactant, a stabilizer, and an acid promoter during heap leaching. The acid promoter can promote the dissolution of gold, and the leaching agent improves the leaching efficiency of gold. The surfactant can effectively reduce the surface tension of the solution, improve the wettability of the gold ore surface, and thereby enhance the dissolution rate of gold in the gold ore. The stabilizer can effectively improve the stability of the composite leaching solution, ensure the stability of the leaching efficiency during the gold ore leaching process, and thus improve the yield of product gold.
[0038] Combining Examples 1-3, Comparative Example 2 and Comparative Example 3, the yield of product gold in Examples 1-3 is higher, which shows that when heap leaching is performed, the pH of the composite leaching solution is preferably 9-11, and the yield of product gold is higher.
[0039] Combining Example 2, Example 4 and Example 5, the yield of product gold in Example 4 is the highest. It can be seen that when preparing the composite leaching solution, the ratio of the leaching agent, surfactant and stabilizer in Example 4 is optimal, so the final yield of product gold is the highest.
[0040] Combining Example 4, Example 6 and Example 7, it can be seen that when heap leaching is performed, when the mass concentration of the leaching agent in the composite leaching solution is 0.05-0.1%, increasing the content of the leaching agent can improve the leaching effect on the powder ore.
[0041] In combination with Example 6, Example 8 and Example 9, the yield of the product gold in Example 6 is the highest. It can be seen that when preparing the composite leaching solution, the surfactant is preferably a mixture of alkyl polyoxyethylene ether and fatty alcohol polyoxyethylene ether, which has a better leaching effect on the powder ore, thereby improving the yield of the final product gold.
[0042] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.
Claims
1. A process for extracting and purifying gold from oxidized gold ore, characterized in that: The following steps are involved: Crushing: crushing the raw ore to obtain powder ore; Heap leaching: the powder ore is first piled up, and then heap leached with a composite leaching solution to obtain a leaching mixture; wherein the raw materials of the composite leaching solution include a leaching agent, a surfactant, a stabilizer, and an acid promoter, and the weight ratio of the leaching agent, the surfactant, and the stabilizer is 1: (0.05-0.15): (0.05-0.10), and the pH of the composite leaching solution is 9-11; Adsorption: using an adsorbent to adsorb the leaching mixture to obtain a gold-loaded material; Desorption: desorbing the gold-loaded material to obtain a desorption solution; Precipitation recovery: Use a precipitant to precipitate and recover the desorption liquid to obtain the product gold.
2. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: The leaching agent includes one of sodium cyanide and sodium carbonate.
3. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: The surfactant includes one or more of alkyl polyoxyethylene ether, fatty alcohol polyoxyethylene ether, palmityl alcohol polyoxyethylene ether, and nonylphenol polyoxyethylene ether.
4. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: The acid accelerator includes one of sulfuric acid, hydrochloric acid and nitric acid.
5. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: The stabilizer includes glucose.
6. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: In the ore crushing step, the particle size of the powder ore is 5-10 mm.
7. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: In the heap leaching step, the mass concentration of the leaching agent in the composite leaching solution is 0.05-0.1%.
8. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: The adsorbent includes activated carbon with a particle size of 0.3-0.5 mm.
9. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: The desorption step comprises: utilizing an acidic solution to desorb the gold-loaded material to obtain a desorption solution, wherein the acidic solution is a hydrochloric acid solution or a sodium hydroxide solution.
10. A process for extracting and purifying gold from oxidized gold ore according to claim 1, characterized in that: The precipitant includes one of zinc powder, iron powder and aluminum powder.