Gold extraction method for carbon-containing refractory gold ore

Abstract

The invention provides a gold extraction method for carbon-containing refractory gold ore, and belongs to the technical field of hydrometallurgy. The carbon-containing refractory gold ore is placed in an electrolytic bath containing electrolyte, the pH of ore pulp is adjusted to be larger than 2 and smaller than or equal to 7, voltage is applied to an electrode, and electrochemical oxidation pretreatment is carried out. And then, the pH value of the ore pulp is adjusted to be larger than or equal to 1 and smaller than or equal to 2, anion resin is added, stirring and gold leaching are conducted, and efficient recovery of gold is achieved. According to the method, through electrochemical oxidation pretreatment, oxidation removal of carbon can be effectively achieved, and the gold robbing performance of carbon on gold is eliminated. And meanwhile, acid leaching and recycling of gold in the pretreated gold ore are successfully achieved, the acid-base transformation step of oxidizing slag is reduced, and non-cyanide leaching of gold is achieved. According to the method, gold in the carbon-containing refractory gold ore can be efficiently recycled, the technological process is short, operation is easy and convenient, environment friendliness is achieved, and a valuable technical scheme is provided for the field of precious metal hydrometallurgy.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for extracting gold from carbon-containing refractory gold ore. Background Art

[0002] Driven by the strong demand for sustained economic development, the demand for gold, as a key cornerstone of currency reserves and an indispensable metal for high-tech industries, has shown a rapid growth trend in recent years. Benefiting from this, the gold industry has made great progress, and my country has been ranked first in the world in gold production for many years with its excellent production capacity. However, the proportion of refractory gold resources in existing gold mines has increased year by year. Among the proven geological reserves, the gold reserves of refractory gold mines exceed 3,000 tons, accounting for more than 1 / 3 of the total proven reserves. Therefore, it is urgent to develop a convenient and efficient method for refractory gold mines.

[0003] Currently, cyanidation still occupies a dominant position in the gold industry, and more than 80% of the world's annual gold production relies on this process. However, cyanidation is not perfect. Although cyanidation gold leaching has a mature process, it is highly toxic, pollutes the environment, and has a slow leaching rate. Especially when treating carbon-containing gold ores, the "gold-robbing effect" produced by carbon will cause the cyanidation leaching index to deteriorate significantly.

[0004] The roasting method is to roast the ore within a specific temperature range to make the carbon oxidize or lose its activity, and the sulfide is also oxidized, thereby opening the fine packaging structure of the fine-grained gold ore and creating favorable conditions for subsequent cyanide leaching. Although the roasting method can improve the recovery rate of gold, its investment cost is high, energy consumption is huge, and it is more polluting to the environment. Against the backdrop of increasingly stringent environmental standards, these disadvantages are becoming more and more prominent.

[0005] In addition, relevant studies have shown that adding oxidants such as chlorine and hypochlorite to the slurry can remove carbon from difficult-to-treat gold ores and oxidize carbon-containing substances into CO or CO2, thereby reducing the "gold-robbing effect" of carbonaceous minerals. However, chlorine has problems such as low utilization rate and environmental pollution in practical applications, which greatly limits its industrial application. Although sodium hypochlorite can increase the leaching rate of gold in carbonaceous gold ores, sodium hypochlorite is a liquid, which makes it face great difficulties in transportation and storage.

[0006] In the prior art, the patent with publication number CN107988489A provides a new method for heat preservation leaching of carbon-containing gold ore, ore grinding: crushing the raw ore through a crushing device and then grinding to obtain ore pulp; leaching pretreatment: adjusting the mass concentration of the ore pulp obtained by grinding to 40%, pouring it into a stirrer, adding an oxidant, a leaching aid and a pH value adjuster in sequence, and stirring for 2 hours; heat preservation cyanide carbon leaching: pouring the pretreated ore pulp into an insulation container and heating it to 90°C, and keeping the ore pulp temperature at 90°C unchanged, then adding an adsorbent and a gold leaching agent in sequence, sealing the insulation container, keeping it warm and standing for 24 hours, extracting the gold-loaded carbon, and separating the ore pulp from solid and liquid. However, in the process of gold leaching, the raw materials are highly toxic, environmentally polluting, and the subsequent gold extraction is greatly affected by the carbon in the ore. The patent with publication number CN105838901B provides a method for extracting gold by roasting pretreatment of sulfur-arsenic-containing carbon-containing gold ore, wherein sodium salt is added to the sulfur-arsenic-containing carbon-containing gold ore and mixed, and then rapidly roasted under oxygen-rich conditions, and the resulting roasted sand is washed with water and then cyanide leached. Although this method has good removal effects of sulfur, arsenic and carbon, and a high gold leaching rate, it consumes a lot of energy and causes serious environmental pollution. Summary of the invention

[0007] In view of the technical problems existing in the background technology, the present application provides a method for extracting gold from carbon-containing refractory gold ore, aiming to solve the problems of difficulty in eliminating carbon in existing carbon-containing refractory gold ore, complex process flow, high energy consumption in the gold leaching process, and environmental pollution.

[0008] The present application provides a method for extracting gold from carbon-containing refractory gold ore, comprising the following steps: S1. Grind the carbonaceous gold ore, add it to the electrolytic cell, stir it evenly, add a first pH regulator to adjust the pH value of the slurry so that 2<pH≤7, and perform electrolytic pretreatment; S2. Continue to add anion exchange resin to the slurry, add a second pH adjuster to adjust the pH value of the slurry so that 1≤pH≤2, and stir to leaching gold; S3. Separate the gold-loaded resin from the ore pulp, circulate the tailings after purification and discharge the tailings after neutralization.

[0009] In the technical scheme of the embodiment of the present application, the gold-robbing effect of carbonaceous minerals is eliminated by electrochemical pretreatment, and direct leaching of gold is achieved without solid-liquid separation, which significantly improves the recovery rate of gold in carbon-containing gold mines, successfully realizes the acid leaching and recovery of gold in gold mines after pretreatment, reduces the acid-base transformation steps of oxidized slag, and realizes the simultaneous development of carbon-containing gold mine pretreatment and leaching recovery processes. In the entire process, liquid recycling is used to maximize resource utilization; the tailings do not contain toxic and harmful substances, eliminating potential environmental pollution hazards; at the same time, no harmful waste gas is generated in the entire production process, which fully demonstrates the green and environmentally friendly characteristics of the process, which is in line with the current concept of sustainable development. In addition, by adjusting the pH value of the slurry in steps, the removal of impurities such as carbon in the mineral is guaranteed while ensuring that the gold has a high leaching rate. In the subsequent gold extraction process, it can be directly extracted by conventional resins, and has a good extraction effect. The method has the advantages of simple equipment, short process, low reagent consumption, good environmental benefits and good metal recovery effect, and shows good application prospects in the treatment of carbon-containing gold mines.

[0010] In some embodiments, in step S1, the electrolysis voltage is 2-12V, and the electrolysis time is 3-8h.

[0011] In this embodiment, by using a specific electrolysis voltage and electrolysis time, sulfides, carbonaceous minerals, etc. in the gold ore can be oxidized by the oxide generated at the anode, so that the sulfides wrap the naked gold and eliminate the influence of carbonaceous minerals, etc.

[0012] In some embodiments, in step S2, the stirring leaching time is 1 to 6 hours.

[0013] In this embodiment, the gold dissolved in the slurry and entering the liquid phase is fully contacted with the resin through stirring leaching, so that the gold is adsorbed by the resin, thereby realizing gold recovery.

[0014] In some embodiments, in step S1, the electrolyte in the electrolyte is one or a combination of any two of sodium chloride and / or potassium chloride, sodium bromide and / or potassium bromide, potassium iodide and / or sodium iodide; the mass concentration of the electrolyte is 20~200g / L.

[0015] In this embodiment, one or a combination of any two of sodium chloride and / or potassium chloride, sodium bromide and / or potassium bromide, potassium iodide and / or sodium iodide is used as the electrolyte to produce oxides by anode electrolysis to oxidize impurities such as sulfides and carbonaceous minerals in the gold ore.

[0016] In some embodiments, in step S1, the fine grinding refers to a grinding fineness of -0.074 mm accounting for 80% to 95%.

[0017] In this embodiment, by grinding the mineral to a specific fineness, the subsequent electrolysis to eliminate impurities and leaching gold can be more effective.

[0018] In some embodiments, in step S1, the mass concentration of the slurry in the electrolytic cell is 5% to 40%.

[0019] In some embodiments, in step S1, the first pH adjuster is hydrochloric acid.

[0020] In this embodiment, the pH value of the slurry is first adjusted to 2-7 by hydrochloric acid, and the carbon and sulfide in the mineral can be electrolytically oxidized in combination with the electrolysis conditions, without directly adjusting the pH value of the slurry to a range suitable for electrolytic gold, thereby preventing the sulfide on the surface of the gold mineral from generating acid during the electrolysis process, causing the pH value of the solution to be too low, which would seriously affect the subsequent effect of the resin in adsorbing gold.

[0021] In some embodiments, in step S2, the second pH adjuster is hydrochloric acid or sulfuric acid.

[0022] In this embodiment, the pH value of the ore pulp is adjusted again to a range suitable for electrolytic gold during the gold leaching process. The pH value of the ore pulp is adjusted step by step without affecting the effect of the resin on gold adsorption.

[0023] In some embodiments, in step S2, the anion exchange resin includes: YKTG01, YKTG04, D201, D201×7, XJZY resin models; the addition amount of the anion exchange resin is 10~40ml / L.

[0024] In this embodiment, since the pH value is adjusted step by step, the gold adsorption resin can be a conventional resin and has a good adsorption effect.

[0025] In some embodiments, in step S1, the material of the electrolytic cell is one of PP, fiberglass, PPH or PPR; the material of the anode of the electrolytic cell is one of graphite, ruthenium-plated titanium plate or ruthenium-plated titanium mesh, and the material of the cathode is one of titanium plate, titanium mesh or graphite.

[0026] In this embodiment, suitable electrolytic materials can enable the electrolytic reaction to proceed smoothly.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. DETAILED DESCRIPTION

[0028] The following is a detailed description of the embodiments of the technical solution of the present application. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In order to solve the problems of the difficulty in eliminating carbon in existing carbon-containing difficult-to-treat gold mines, the gold-robbing effect that is easy to produce, the high energy consumption of the gold leaching process, and environmental pollution, the present application provides a method for extracting gold from carbon-containing difficult-to-treat gold mines. The gold-robbing effect of carbonaceous minerals is eliminated through electrochemical pretreatment, and direct leaching of gold is achieved without solid-liquid separation, which significantly improves the recovery rate of gold in carbon-containing gold mines, successfully realizes the acid leaching and recovery of gold in gold mines after pretreatment, reduces the acid-base transformation steps of oxidized slag, and realizes the simultaneous implementation of carbon-containing gold mine pretreatment and leaching recovery processes. During the entire process, liquids are recycled to maximize resource utilization; tailings do not contain toxic and harmful substances, eliminating potential environmental pollution risks; at the same time, no harmful waste gas is generated during the entire production process, which fully demonstrates the green and environmentally friendly characteristics of the process, which is in line with the current concept of sustainable development. In addition, because conventional resins have poor adsorption effects under conditions where the pH value is too low, and the sulfides in the gold ore will produce acid during the electrolysis process, the pH value will gradually decrease during the electrolysis process, resulting in the conventional resin's adsorption effect on gold being affected by the step-by-step adjustment of the pH value in the prior art due to the gradual decrease in the pH value. However, the present application adjusts the pH value of the slurry in steps to ensure the removal of impurities such as carbon in the mineral while ensuring a high leaching rate for gold. In the subsequent gold extraction process, conventional resins can be used for direct extraction, and a good extraction effect can be achieved. This method has the advantages of simple equipment, short process, low reagent consumption, good environmental benefits, and good metal recovery effects, and shows good application prospects in the treatment of carbon-containing gold ores.

[0032] The present application provides a method for extracting gold from carbon-containing refractory gold ore, comprising the following steps: S1. Grind the carbonaceous gold ore, add it to the electrolytic cell, stir it evenly, add a first pH regulator to adjust the pH value of the slurry so that 2<pH≤7, and perform electrolytic pretreatment; S2. Continue to add anion exchange resin to the slurry, add a second pH adjuster to adjust the pH value of the slurry so that 1≤pH≤2, and stir to leaching gold; S3. Separate the gold-loaded resin from the ore pulp, circulate the tailings after purification and discharge the tailings after neutralization.

[0033] Furthermore, in some embodiments, in step S1, the voltage of the electrolysis is 2-12V, and the time of the electrolysis is 3-8h.

[0034] In the technical solution of the embodiment of the present application, through a specific electrolysis voltage and electrolysis time, the sulfides, carbonaceous minerals, etc. in the gold ore can be oxidized by the oxides generated at the anode, so that the sulfides wrap the naked gold and eliminate the influence of the carbonaceous minerals, etc.

[0035] Furthermore, in some embodiments, in step S2, the stirring leaching time is 1 to 6 hours.

[0036] In the technical solution of the embodiment of the present application, through stirring leaching, the gold dissolved in the slurry and entering the liquid phase is fully contacted with the resin, so that the gold is adsorbed by the resin, thereby realizing gold recovery.

[0037] Furthermore, in some embodiments, in step S1, the electrolyte in the electrolyte is one or a combination of any two of sodium chloride and / or potassium chloride, sodium bromide and / or potassium bromide, potassium iodide and / or sodium iodide; and the mass concentration of the electrolyte is 20~200g / L.

[0038] In the technical solution of the embodiment of the present application, one or a combination of any two of sodium chloride and / or potassium chloride, sodium bromide and / or potassium bromide, potassium iodide and / or sodium iodide is used as an electrolyte to produce oxides by anode electrolysis to oxidize impurities such as sulfides and carbonaceous minerals in the gold ore.

[0039] Furthermore, in some embodiments, in step S1, the fine grinding refers to a grinding fineness of -0.074 mm accounting for 80% to 95%.

[0040] In the technical solution of the embodiment of the present application, by grinding the mineral to a specific fineness, the subsequent electrolysis to eliminate impurities and leaching gold can be better.

[0041] Furthermore, in some embodiments, in step S1, the mass concentration of the slurry in the electrolytic cell is 5% to 40%.

[0042] Furthermore, in some embodiments, in step S1, the first pH adjuster is hydrochloric acid.

[0043] In the technical solution of the embodiment of the present application, the pH value of the slurry is first adjusted to 2-7 by hydrochloric acid, and the carbon and sulfide in the mineral can be electrolytically oxidized in combination with the electrolysis conditions, without directly adjusting the pH value of the slurry to a range suitable for electrolytic gold, thereby preventing the sulfide on the surface of the gold mineral from generating acid during the electrolysis process, causing the pH value of the solution to be too low, which would seriously affect the subsequent effect of the resin in adsorbing gold.

[0044] Furthermore, in some embodiments, in step S2, the second pH adjuster is hydrochloric acid or sulfuric acid.

[0045] In the technical solution of the embodiment of the present application, the pH value of the slurry is adjusted again to a range suitable for electrolytic gold during the gold leaching process, and the pH value of the slurry is adjusted step by step without affecting the effect of the resin on gold adsorption.

[0046] Furthermore, in some embodiments, in step S2, the anion exchange resin includes: YKTG01, YKTG04, D201, D201×7, XJZY resin models; the addition amount of the anion exchange resin is 10~40ml / L.

[0047] In the technical solution of the embodiment of the present application, since the pH value is adjusted step by step, the gold adsorption resin can be a conventional resin and has a good adsorption effect.

[0048] Furthermore, in some embodiments, in step S1, the material of the electrolytic cell is one of PP, fiberglass, PPH or PPR; the material of the anode of the electrolytic cell is one of graphite, ruthenium-plated titanium plate or ruthenium-plated titanium mesh, and the material of the cathode is one of titanium plate, titanium mesh or graphite.

[0049] In the technical solution of the embodiment of the present application, suitable electrolytic materials can enable the electrolytic reaction to proceed smoothly.

[0050] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0051] Example 1 This embodiment provides a method for extracting gold from carbon-containing refractory gold ore, which specifically includes the following steps: (1) Grind the gold ore to -0.074mm with a mass content of 80%, add it into a PP electrolytic cell with 20g / L sodium chloride electrolyte, a ruthenium-plated titanium plate as the anode and a titanium mesh as the cathode. The mass concentration of the slurry in the electrolytic cell is 5%, and the pH of the slurry is adjusted to 7 with hydrochloric acid. Apply a voltage of 12V between the anode and the cathode, and perform electrolysis pretreatment for 3 hours under stirring.

[0052] (2) Add 10 ml / L of D201×7 macroporous anion exchange resin to the slurry. During the leaching process, hydrochloric acid is used to maintain the pH of the slurry solution at 2. Stir and leach for 6 hours.

[0053] (3) After leaching, the gold-loaded resin in the slurry is separated, and then the solid and liquid are separated.

[0054] The sources and performance parameters of raw materials are as follows: The raw materials used are all carbon-containing refractory gold ores produced by a domestic mining company. The main element contents are shown in Table 1. The carbon mainly exists in the form of organic carbon and elemental carbon, with contents of 47.18% and 22.99% respectively, and the carbonate content is 29.83%. Under the condition of sufficient cyanide, the direct cyanide leaching rate of this raw material is 23.52%.

[0055] Table 1 Main element contents of raw ore The gold grade in the leaching residue of this embodiment was analyzed, and the gold leaching rate was calculated to be 93.30%.

[0056] Examples 2-3 and Comparative Examples 1-2 Examples 2-3 and Comparative Examples 1-2 respectively provide a method for extracting gold from carbon-containing refractory gold ore. Compared with Example 1, the difference is that the voltage in step (1) is different. The voltages corresponding to the embodiments and comparative examples are shown in Table 2. The other steps are substantially the same as those in Example 1 and will not be described in detail herein.

[0057] Table 2 Voltage in Examples 2-3 and Comparative Examples 1-2 The gold grades in the leaching residues in Examples 2-3 and Comparative Examples 1-2 were analyzed respectively, and the gold leaching rates were calculated as shown in Table 3.

[0058] Table 3 Gold leaching rate in Examples 2-3 and Comparative Examples 1-2 It can be seen from the gold leaching rates in Examples 1 to 3 and Comparative Examples 1 to 2 that when the electrolysis voltage in step (1) is in the range of 2 to 12 V, the gold leaching rate is relatively high. When the electrolysis voltage in step (1) is too high or too low, the gold leaching effect will be affected. If the voltage is too high, it is easy to cause side reactions and increase energy consumption, while if the voltage is too low, there will be insufficient reaction power, slow rate, uneven current distribution, etc. Therefore, controlling the appropriate voltage is crucial to the pretreatment effect and the subsequent gold leaching rate.

[0059] Examples 4-5 and Comparative Examples 3-4 Examples 4-5 and Comparative Examples 3-4 respectively provide a method for extracting gold from carbon-containing refractory gold ore. Compared with Example 1, the difference is that the electrolysis time in step (1) is different. The electrolysis time corresponding to each example and comparative example is shown in Table 4. The other steps are substantially the same as those in Example 1 and will not be described in detail herein.

[0060] Table 4 Electrolysis time in step (1) in Examples 4-5 and Comparative Examples 3-4 The gold grades in the leaching residues of Examples 4-5 and Comparative Examples 3-4 were analyzed respectively, and the gold leaching rates were calculated as shown in Table 5.

[0061] Table 5 Gold leaching rate in Examples 4-5 and Comparative Examples 3-4 It can be seen from the gold leaching rates in Examples 4-5 and Comparative Examples 3-4 that when the electrolysis time in step (1) is within 3-8 hours, the gold leaching rate is high. When the electrolysis time in step (1) is too short, the gold leaching effect will be affected, which is due to the poor pretreatment effect. When the electrolysis time is too long, although the gold leaching effect is not much different from that in Example 1, it will increase energy consumption.

[0062] Examples 6-7 and Comparative Examples 5-6 Examples 6-7 and Comparative Examples 5-6 respectively provide a method for extracting gold from carbon-containing refractory gold ore. Compared with Example 1, the difference is that the leaching time in step (2) is different. The leaching time corresponding to each example and comparative example is shown in Table 6. The other steps are substantially the same as those in Example 1 and are not described in detail here.

[0063] Table 6 Gold immersion time in step (2) in Examples 6-7 and Comparative Examples 5-6 The gold grades in the leaching residues of Examples 6-7 and Comparative Examples 5-6 were analyzed respectively, and the gold leaching rates were calculated as shown in Table 7.

[0064] Table 7 Gold leaching rate in Examples 6-7 and Comparative Examples 5-6 It can be seen from the gold leaching rates in Examples 6-7 and Comparative Examples 5-6 that when the gold leaching time in step (2) is within 1-6 hours, the gold leaching rate is relatively high. When the leaching time in step (2) is too short, the gold leaching effect will be affected due to insufficient reaction and kinetic limitation. When the leaching time is too long, not only the possibility of side reactions will increase, but also the energy consumption cost will increase.

[0065] Comparative Example 7 This comparative example provides a method for extracting gold from carbon-containing refractory gold ore. Compared with Example 1, the difference is that in step (1), the pH value of the slurry is directly adjusted to 2, and in step (2), the pH value is not adjusted. The other steps are substantially the same as those in Example 1 and are not described in detail here.

[0066] The gold grade in the leached residue before adding the resin in this comparative example was analyzed, and the gold leaching rate was calculated to be 93.06%. The gold grade in the filtrate after the resin gold extraction was completed was then analyzed, and the gold extraction rate was obtained to be 82.39%.

[0067] It can be seen from the test results of Comparative Example 7 that the gold extraction effect is poor. Therefore, directly adjusting the pH of the solution to 2 during pretreatment will have an adverse effect on the subsequent resin adsorption of gold. This is because the electrolysis of sulfides in the minerals during the pretreatment electrolysis process will produce acid, which will further reduce the pH value of the solution. Too low a pH value will protonate the functional groups of the resin, which may damage the resin structure and reduce the adsorption capacity; + It competes with other cations for adsorption sites, and the adsorption kinetics slow down.

[0068] Comparative Example 8 This comparative example provides a method for extracting gold from a carbon-containing refractory gold ore. Compared with Example 1, the difference is that in step (1), the pH value of the slurry is directly adjusted to 2, and in step (2), sodium hydroxide is added to readjust the pH value of the slurry to 2. The other steps are substantially the same as those in Example 1 and are not described in detail herein.

[0069] The gold grade in the tailings after the resin gold extraction was analyzed, and the gold leaching rate was 86.57%. This is because after the gold leaching, alkali is added to the leaching residue to adjust the pH value, which will cause the leached gold to re-precipitate and affect the gold leaching index.

[0070] In summary, the present application provides a method for extracting gold from carbonaceous and difficult-to-treat gold ores. The gold-robbing effect of carbonaceous minerals is eliminated by electrochemical pretreatment, and direct leaching of gold is achieved without solid-liquid separation, which significantly improves the recovery rate of gold in carbonaceous gold ores, and realizes the simultaneous development of carbonaceous gold ore pretreatment and leaching recovery processes. During the entire process, liquids are recycled to maximize resource utilization; tailings do not contain toxic and harmful substances, eliminating potential environmental pollution hazards; at the same time, no harmful waste gas is generated during the entire production process, which fully demonstrates the green and environmentally friendly characteristics of the process, which is in line with the current concept of sustainable development. In addition, by adjusting the pH value of the slurry in steps, while ensuring the removal of impurities such as carbon in the mineral, gold has a higher leaching rate. In the subsequent gold extraction process, it can be directly extracted by conventional resins, and has a higher extraction effect. The method has the advantages of simple equipment, short process, low reagent consumption, good environmental benefits and good metal recovery effect, and shows good application prospects in the treatment of carbonaceous gold ores.

[0071] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for extracting gold from carbon-containing refractory gold ore, characterized in that: The following steps are involved: S1. Grind the carbonaceous gold ore, add it to the electrolytic cell, stir it evenly, add a first pH regulator to adjust the pH value of the slurry so that 2 < pH ≤ 7, and perform electrolytic pretreatment; S2. Continue to add anion exchange resin to the slurry, add a second pH adjuster to adjust the pH value of the slurry so that 1≤pH≤2, and stir to leaching gold; S3. Separate the gold-loaded resin from the ore pulp, circulate the tailings after purification and discharge the tailings after neutralization.

2. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S1, the voltage of the electrolysis is 2-12V, and the time of the electrolysis is 3-8h.

3. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S2, the stirring and leaching time is 1 to 6 hours.

4. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S1, the electrolyte in the electrolyte solution is one or a combination of any two of sodium chloride and / or potassium chloride, sodium bromide and / or potassium bromide, potassium iodide and / or sodium iodide; the mass concentration of the electrolyte is 20-200 g / L.

5. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S1, the fine grinding refers to the grinding fineness of -0.074mm accounting for 80% to 95%.

6. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S1, the mass concentration of the slurry in the electrolytic cell is 5% to 40%.

7. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S1, the first pH adjuster is hydrochloric acid.

8. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S2, the second pH adjuster is hydrochloric acid or sulfuric acid.

9. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S2, the anion exchange resin includes: YKTG01, YKTG04, D201, D201×7, XJZY resin; the addition amount of the anion exchange resin is 10-40 ml / L.

10. The method for extracting gold from carbon-containing refractory gold ore according to claim 1, characterized in that: In step S1, the material of the electrolytic cell is one of PP, fiberglass, PPH or PPR; the material of the anode of the electrolytic cell is one of graphite, ruthenium-plated titanium plate or ruthenium-plated titanium mesh, and the material of the cathode is one of titanium plate, titanium mesh or graphite.

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