Method for analyzing and extracting gold from gold-loaded resin containing base metal

Abstract

The invention discloses a method for analyzing and extracting gold from gold-loaded resin containing base metal, and relates to the technical field of precious metal metallurgy. The method comprises the following steps: step 1, pickling and resolving metal zinc; 2, metal copper is analyzed through the agent at the normal temperature, a small amount of gold ions in analysis liquid are recycled through activated carbon, and gold mud is obtained after electrodeposition; thirdly, the gold-loaded resin is circularly washed through alkaline thiocyanate, and electrodeposition treatment is conducted on the separated gold-containing pregnant solution to obtain gold mud; 4, carrying out acid regeneration on the desorbed resin; and 5, carrying out alkali neutralization on the resin subjected to acid regeneration, and reducing the resin into OH-type resin for recycling. According to the method, the gold-loaded resin with high base metal content can be effectively analyzed, meanwhile, the electrodeposition energy consumption and the cost of electrodeposition equipment are reduced, and the analysis gold extraction time is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of precious metal metallurgy, and in particular to a method for extracting gold from a gold-loaded resin containing base metals. Background Art

[0002] Existing resin-based slurry gold extraction processes use anionic resins with high exchange capacity, which have strong adsorption capacity and strong absorption capacity for gold-cyanide complexes. However, these resins also adsorb a large number of base metals, resulting in a large amount of copper-cyanide complexes in the resin. When the ore contains a large amount of cyanide-soluble copper, the amount of copper adsorbed in the resin will far exceed the gold content, resulting in a long desorption time for the gold-loaded resin and the need for greater electrolytic deposition equipment capacity to precipitate the copper ions. Furthermore, although the high chemical activity of other base metals such as zinc and nickel makes them less susceptible to electrolysis and thus does not directly affect the electrolytic desorption time of gold, a high zinc ion content in the desorption solution can reduce the maximum concentration of other metal ions, indirectly reducing the desorption rate of other metal ions, especially precious metals such as gold.

[0003] For example, in the traditional thiocyanate desorption method, when the copper content of the gold-loaded resin is low, the entire desorption cycle is about 2-3 days. When the copper content of the gold-loaded resin is more than 5 times the gold content, the entire desorption cycle will exceed 7 days. To shorten the desorption cycle, existing technology has to significantly increase the capacity of the electrolytic deposition equipment.

[0004] For example, in the traditional thiourea method, when the copper content of the gold-loaded resin is low, the entire analysis cycle is approximately 0.5-2 days. When the copper content of the gold-loaded resin is more than 5 times the gold content, the entire analysis cycle will exceed 4 days. Although the analysis time seems much shorter than the thiocyanate method, the acidic thiourea used in the thiourea method is a highly corrosive solution, which requires strict corrosion protection of the equipment and is also very expensive.

[0005] Some existing technologies have improved upon the traditional thiocyanate desorption method to shorten the desorption cycle, reduce electrolytic energy consumption, and lower equipment costs. For example, Chinese patent application CN118326167A utilizes a process based on "graded control of temperature, concentration, and chemical environment using ammonium thiocyanate." On one hand, this process relies on ammonium thiocyanate at every stage, which desorbs base metals while also desorbing large amounts of precious metals such as gold. This makes it difficult to separate base metals from precious metals in the desorption solution. If the base metals in the desorption solution at each stage are forcibly separated, precious metals such as gold will also be separated, resulting in gold loss. Furthermore, this process requires heating the ammonium thiocyanate solution to 60°C-72°C to improve the desorption rate of copper, gold, and silver. However, anionic resins tend to decompose at temperatures above 60°C, and the ammonium thiocyanate solution also needs to be heated to 45°C-55°C during the low-temperature stage to desorb zinc from the resin, further increasing production costs and complicating the desorption gold extraction process. Summary of the Invention

[0006] In view of the above-mentioned defects or deficiencies in the prior art, the present invention provides a method for extracting gold from a gold-loaded resin containing base metals, which can effectively overcome the defects mentioned in the background art.

[0007] One aspect of the present invention provides a method for extracting gold from a gold-loaded resin containing base metals, comprising the following steps: Step 1: Use 50-150g / L hydrochloric acid or sulfuric acid solution to circulate and wash the gold-loaded resin containing base metals in the resin slurry gold extraction process for 4-12 hours at room temperature; Step 2: Use any of the following reagents to wash the gold-loaded resin after washing in step 1 for 4-12 hours at room temperature: Reagent 1: A mixed solution of 0.1-30g / L sodium cyanide and 0.5-5g / L sodium hydroxide; Reagent 2: a mixed solution of 20-100 g / L sodium nitrate and 0.5-5 g / L sodium hydroxide; Reagent 3: a mixed solution of 20-80 g / L thiocyanate and 0.5-5 g / L sodium hydroxide; Circulating the analytical solution through an activated carbon adsorption column to obtain gold-loaded carbon, analyzing the gold-loaded carbon to obtain a gold-containing analytical solution, and performing a first electrowinning treatment on the gold-containing analytical solution to obtain gold mud; Step 3: The gold-loaded resin washed in step 2 is circulated and washed with a mixed solution of 80-250 g / L thiocyanate and 5-25 g / L sodium hydroxide at 50-60° C. for 24-72 hours, and the resolved gold-containing precious liquid is subjected to a second electrowinning treatment to obtain gold mud; Step 4: Use 20-80g / L sulfuric acid or hydrochloric acid solution to wash the resin after the decomposition in step 3 for 4-12 hours; Step 5: The resin washed in step 4 is circulated and washed with 20-40 g / L sodium hydroxide solution for 4-12 hours to generate OH-type resin.

[0008] Furthermore, when the zinc content or nickel content of the gold-loaded resin is lower than a preset threshold, or when the gold-loaded resin is a weakly basic anion exchange resin, step 1 is omitted.

[0009] Furthermore, when the gold-loaded resin is a strongly basic anion exchange resin, the step 2 uses reagent 3.

[0010] Furthermore, before step 1, the method further includes: washing the gold-loaded resin with deionized water to remove ore particles in the resin.

[0011] Furthermore, the flow rate of the circulating washing in step 1 and step 2 is 2-4 BV / h.

[0012] Furthermore, between step 1 and step 2, the method further comprises: washing the resin with deionized water at a flow rate of 2-4 BV / h for 2 hours.

[0013] Furthermore, between step 3 and step 4, the method further comprises: washing the resin with deionized water at a flow rate of 2-4 BV / h for 2 hours.

[0014] Furthermore, between step 4 and step 5, the method further comprises: washing the resin with deionized water at a flow rate of 2-4 BV / h for 2 hours.

[0015] Furthermore, the cycle washing time of step 1 and step 2 is 6-8 hours.

[0016] Furthermore, the barren solution after the electrolytic deposition in step three is further used as a cleaning solution for the gold-loaded resin in step two.

[0017] The method of the present invention utilizes a technical approach consisting of "stepwise decomposition of different base metals using different chemical reagents at room temperature" → "recovering gold from the base metal decomposition solution using activated carbon" → "decomposition and extraction of gold from the gold-containing precious solution using alkaline thiocyanate" → "recovering and regenerating the resin's adsorption capacity." This method can effectively decompose gold-loaded resins with high base metal contents, while simultaneously reducing electrolytic energy consumption and equipment costs, and shortening the extraction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1This is a process flow chart of a method for extracting gold from a gold-loaded resin containing base metals, provided in one embodiment of the present application; Figure 2 This is a schematic diagram of the cumulative absorption rate of various metals in the process of recovering gold from a base metal analysis solution by activated carbon provided by one embodiment of the present application; Figure 3 This is a schematic diagram of an apparatus for recovering gold from a base metal analysis solution using activated carbon provided in one embodiment of the present application. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] The present invention aims to overcome the shortcomings of the prior art by providing a novel process for the efficient and economical desorption (also known as desorption, referred to herein as desorption) of gold-loaded resins containing high base metal contents. Specifically, gold recovery from gold-loaded resins involves two main steps: first, transferring the gold or various metals adsorbed on the resin to a desorption solution; and second, using electroreduction technology to reduce the metal ions in the solution to metallic metals. The concept of the present invention is to preferentially desorb base metals in stages, eliminating the need for electrolytic deposition (electrolytic deposition) of these base metals. This significantly reduces the amount of metal ions entering the second step under the same equipment conditions, significantly reducing the power consumption of electrolysis and significantly shortening the desorption time.

[0021] Table 1 shows the physicochemical properties of various types of metal ions combined with cyanide complex ions (the resin adsorbs metal cyanide complexes), from which the base metal types for priority analysis can be screened out.

[0022] Table 1 Because zinc easily forms zinc hydroxide precipitates in alkaline environments, this precipitate can clog the resin pores and reduce the subsequent gold and silver desorption rate. Furthermore, while zinc's high chemical activity makes it less susceptible to electrolysis and thus does not directly affect the gold electrolysis time, a high zinc ion content in the solution can reduce the maximum concentration of other metal ions, indirectly slowing the desorption rate of these ions, particularly precious metals like gold. Therefore, zinc becomes the most direct interfering factor in the gold-loaded resin desorption process.

[0023] While copper and gold cyanide complexes share the same adsorption sites on the resin, the concentration of copper is often 5-50 times that of gold. Failure to prioritize copper removal will severely inhibit gold desorption. Furthermore, copper electrolysis takes an extremely long time, leading to a desorption cycle of up to seven days.

[0024] While other base metals such as nickel, cobalt, and iron are also degraded during alkaline thiocyanate desorption, they are either present at extremely low concentrations or do not compete with the electrolytic solution, simply increasing the solution's conductivity. Therefore, the cost of a dedicated desorption step outweighs the benefits. In other words, prioritizing zinc and copper resolves 90% of the base metal problem, leaving the remaining base metals to meet industry needs without additional treatment.

[0025] In summary, the present invention considers various factors and decides to prioritize the analysis of zinc in base metals, then the analysis of copper in base metals, and finally the analysis of gold in resin.

[0026] Furthermore, Table 2 shows the resolution of various metal ions in the resin by different types of agents obtained by the applicant through a large number of experimental tests, which can be used as a reference for implementing the present invention.

[0027] Table 2 Note: ╳ indicates almost no resolution; ╳╳ indicates no resolution; √ indicates partial resolution; √√ indicates a resolution rate higher than 90% See also Figure 1 One embodiment of the present application provides a method for extracting gold from a gold-loaded resin containing base metals, comprising the following steps: First, wash the gold-loaded resin. You can rinse it with deionized water to eliminate particulate impurities in the resin, and then perform the following steps: Step S101: using 50-150 g / L hydrochloric acid or sulfuric acid solution to circulate and wash the base metal-containing gold-loaded resin in the resin slurry gold extraction process at room temperature for 4-12 hours.

[0028] According to the physical and chemical properties of zinc in Table 1 above, the stability constant of zinc cyanide complex logβ4=19 is much lower than the stability constant of gold cyanide complex logβ2=38.3, and also much lower than the stability constant of copper cyanide complex logβ4=25.3. Therefore, under acidic conditions, cyanide (CN -) easily combines with H⁺ to form volatile HCN, causing the dissociation of zinc complexes. However, acidic conditions have little effect on precious metal complexes such as gold and silver. Sulfuric acid and hydrochloric acid are basic chemical raw materials, much cheaper than other resolving agents, making them ideal for creating an acidic environment. Therefore, this embodiment preferably uses hydrochloric acid or sulfuric acid solution as a resolving agent for zinc in gold-loaded resins, particularly for high-base metal gold-loaded resins with zinc contents >1000 ppm. This avoids the technical issue of heating ammonium thiocyanate solution when resolving zinc, simplifying the production process.

[0029] Specifically, the base metal-loaded gold resin used in the resin slurry gold extraction process is circulated and washed with a 50-150 g / L hydrochloric acid or sulfuric acid solution at room temperature for 4-12 hours, preferably 6-8 hours. The solution flow rate is 2-4 BV / h (200-400 ml / h), preferably 3 BV / h (300 ml / h). This acid wash removes >98% of the zinc, thereby reducing competition between the base metal zinc and the precious metal in subsequent desorption steps. More specifically, this step utilizes an acid wash circulation system consisting of an acid-resistant desorption column, a circulation pump, and an HCN gas absorption device (such as an alkali spray tower). First, the gold-loaded resin is loaded into the desorption column and rinsed with deionized water until free of particulate impurities. Then, a 50-150 g / L sulfuric acid (or hydrochloric acid) solution is injected and the cycle is initiated at room temperature (approximately 20-25°C). The circulated wash is continued at a flow rate of 2-4 BV / h (200-400 ml / h) for 4-12 hours, and the Zn concentration is monitored. 2+ The concentration is reduced to < about 100ppm; after completion, the acid liquid is discharged to the tailings pond / sedimentation tank; finally, the resin is rinsed with deionized water for about 2 hours until it reaches neutral (pH=7).

[0030] It is worth noting that when the zinc content in the gold-loaded resin is less than about 1000 ppm, the competition of zinc for gold desorption is negligible, so this step can be omitted.

[0031] Step S102: Circulate and wash the gold-loaded resin washed in step S101 at room temperature for 4-12 hours using any of the following reagents: Reagent 1: A mixed solution of 0.1-30g / L sodium cyanide and 0.5-5g / L sodium hydroxide; Reagent 2: a mixed solution of 20-100 g / L sodium nitrate and 0.5-5 g / L sodium hydroxide; Reagent 3: a mixed solution of 20-80 g / L thiocyanate and 0.5-5 g / L sodium hydroxide; The analytical solution is circulated through an activated carbon adsorption column to obtain gold-loaded carbon, the gold-loaded carbon is analyzed to obtain a gold-containing analytical solution, and the gold-containing analytical solution is subjected to a first electrowinning treatment to obtain gold mud.

[0032] Specifically, this step is used to resolve copper. Since the copper-cyanide complex in the gold-loaded resin is stable under acidic conditions, this step requires an alkaline agent for resolution. After extensive experimental research, the inventors of this application found that the following three agents can achieve effective resolution of copper: Reagent 1: A mixed solution of sodium cyanide and sodium hydroxide. In an alkaline environment, the CN of sodium cyanide (NaCN) - ions and Cu ⁺ ions form more stable [Cu(CN)3] 2- , thereby making it easier to displace the copper adsorbed on the resin. Preferably, the agent uses a mixed solution of 0.1-30g / L sodium cyanide and 0.5-5g / L sodium hydroxide. This agent is particularly suitable for resins with high copper content.

[0033] Reagent 2: A mixed solution of sodium nitrate and sodium hydroxide. In an alkaline environment, high concentrations of NO3 - By competing for adsorption sites through ion exchange, the copper adsorbed by the resin can be easily replaced. Preferably, the reagent uses a mixed solution of 20-100g / L sodium nitrate and 0.5-5g / L sodium hydroxide.

[0034] Reagent 3: Mixed solution of thiocyanate and sodium hydroxide. In an alkaline environment, use SCN - With Cu + Generate [Cu(SCN)4] 3- Preferably, the reagent uses 20-80 g / L of thiocyanate and 0.5-5 g / L of sodium hydroxide to form a mixed solution.

[0035] The specific operation process of copper analysis is as follows: inject the selected reagent into the analytical column at room temperature (about 20-25℃) and start the circulation; continue the circulation at a flow rate of 2-4BV / h (200-400ml / h) for 4-12 hours, and monitor the Cu 2+ The concentration dropped to the target concentration.

[0036] Furthermore, experiments have shown that when alkaline ammonium thiocyanate is used to decompose copper, the gold loss rate reaches 25%. Other alkaline agents such as sodium cyanide and sodium nitrate also cause significant gold dissolution. Gold exists in the alkaline liquid phase as a stable anion and cannot spontaneously precipitate. Therefore, while decomposing copper, it is necessary to recover the gold ions in the decomposition solution to solve the problem of gold loss and avoid value loss. After a large number of experimental studies, the inventors found that the microporous structure of activated carbon matches the diameter of the gold cyanide complex (about 0.5nm), while the diameter of the copper / zinc complex is >1nm, which is just blocked by the micropores of the activated carbon. The gold cyanide complex can pass through the micropores of the activated carbon smoothly. However, under normal pH neutral conditions, it is difficult for activated carbon to achieve efficient adsorption of the gold cyanide complex, and the adsorption conditions of activated carbon need to be further improved. Further experiments by the inventors showed that the negative charge on the surface of activated carbon was further enhanced in an alkaline environment, which could ensure that gold and silver existed in the form of low-polarity anionic complexes, and convert the base metals into a highly polar hydrophilic form. At this time, the base metals were repelled by the surface charge of the activated carbon, making the adsorption rate of gold on the activated carbon more than 1,000 times that of zinc. Figure 2 The activated carbon adsorption rates for various metals are shown. The cumulative adsorption rates (recovery rates) for gold and silver are close to 100%, while those for copper and zinc are only 2.5% and 2%, respectively. The cumulative adsorption rate for nickel is 61%, but the low nickel concentration in the solution does not affect subsequent gold electrowinning. The cumulative adsorption rate for iron is 20%. This indicates that the adsorption rates for gold and silver on activated carbon are much higher than those for other base metals. Therefore, adsorbing gold-cyanide complexes on activated carbon in an alkaline environment is a highly effective method for recovering gold.

[0037] See also Figure 3 The desorption solution is then refluxed to the activated carbon adsorption column and circulated to the copper-desorbed desorption solution at a flow rate of 2-4 BV / h (preferably 3 BV / h). To further enhance the negative charge on the activated carbon surface, the carbon bed can be pre-activated with a 1–2% (0.01-0.02 g / ml) NaOH solution. This facilitates the adsorption of gold and the rejection of base metals. After the predetermined adsorption period, the gold-loaded carbon is desorbed to obtain a gold-containing desorption solution. This gold-containing desorption solution is then subjected to a first electrolytic treatment to recover gold sludge.

[0038] In step S103, the gold-loaded resin washed in step S102 is circulated and washed for 24-72 hours using a mixed solution of 80-250 g / L thiocyanate and 5-25 g / L sodium hydroxide at 50-60° C., and the resolved gold-containing precious liquid is subjected to a second electrowinning treatment to obtain gold mud.

[0039] Through the above steps S101 and S102, the zinc and copper in the gold-loaded resin are analyzed and stripped, and the remaining part of the gold-loaded resin adsorbent is mainly gold / silver precious metal cyanide complex.- ) is prone to ligand replacement with the gold-cyanide complex in an alkaline high-temperature environment, so this embodiment uses an alkaline mixed solution of thiocyanate and sodium hydroxide as a gold analytical agent.

[0040] Specifically, the wet resin obtained after step S102 is transferred to an analytical column, and a mixed solution consisting of 80-250 g / L of thiocyanate and 5-25 g / L of sodium hydroxide is preheated to 50-60°C, preferably 55-58°C to balance the reaction rate and the risk of resin decomposition. The mixed solution is pumped into the analytical column and a 24-72 hour circulating wash is started. Samples are taken every 4 hours and the gold content in the resin is tested. When the gold content is less than the target value for three consecutive times, the analysis is terminated, and the gold-containing precious liquid is transferred to an electrowinning tank, and gold mud is obtained after electrowinning treatment.

[0041] This step achieves a gold resolution rate of >94% and a base metal simultaneous resolution rate of <10% through high-temperature dynamic circulation of alkaline thiocyanate. This is because after the graded stripping of base metals, alkaline thiocyanate directionally attacks the gold-cyanide bond in a high-temperature alkaline environment, breaking through the bottleneck of high-base metal resin resolution.

[0042] In step S104, the resin obtained after the decomposition in step S103 is washed in a cycle for 4-12 hours using a 20-80 g / L sulfuric acid or hydrochloric acid solution.

[0043] The acid washing regeneration step of the gold-loaded resin is a key regeneration process after gold desorption. Its goal is to remove the thiocyanate (SCN) adsorbed on the resin. - ), restore the exchange capacity of the resin. The specific principle is: through the H + Replacement of SCN - , converting the resin to the hydrogen form (RH), and the generated thiocyanate (HSCN) is carried away by the acid solution. Specifically, flush the lean resin after thiocyanate desorption with deionized water at a flow rate of 2-4 BV / h (preferably 3 BV / h) for approximately 2 hours until the resin returns to neutrality (pH = 7). Then, pump 20-80 g / L sulfuric acid or hydrochloric acid solution into the regeneration column and circulate it in a closed loop for 4-12 hours.

[0044] In step S105 , the resin washed in step S104 is circulated and washed with a 20-40 g / L sodium hydroxide solution for 4-12 hours to generate an OH-type resin.

[0045] The goal of this step is to convert the resin after hydrogen acid regeneration (RH) to hydroxyl acid (R-OH) to restore the resin's adsorption activity for gold cyanide complex. - Replacement H + The resin is negatively charged, thus restoring the resin's ability to adsorb metal cations. In addition, the OH -It also plays a role in removing residual acid radicals and preventing competitive adsorption.

[0046] Specifically, the acid-regenerated resin is rinsed with deionized water at a flow rate of 2-4 BV / h (preferably 3 BV / h) for 2 hours until the pH reaches 5-7. The weakly acidic or neutral resin can prevent NaOH from reacting violently with residual acid. After rinsing, the resin is transferred to a reaction vessel, and an alkaline solution consisting of 20-40 g / L sodium hydroxide is pumped into the reaction vessel for closed-loop circulation for 4-8 hours, preferably 6 hours, to restore the generation of OH-type resin and restore the adsorption activity of the resin.

[0047] The method for extracting gold from a gold-loaded resin containing base metals can effectively extract gold-loaded resins with high base metal contents, while reducing electrolytic energy consumption and the cost of electrolytic equipment and shortening the time for extracting gold.

[0048] The process of the present invention can be more clearly understood through several embodiments below.

[0049] Example 1 The following process is used to extract gold from a strong base anion gold-loaded resin with a high zinc content: Step 1: Load 100ml of strong base anion gold-loaded resin from the Saipan Mine flotation tailings resin slurry gold extraction system into the analytical column; Step 2: Wash the resin with 100g / L sulfuric acid solution at room temperature (20-25°C) for 6 hours at a washing liquid flow rate of 3BV / h; Step 3: Wash the acid-washed resin with deionized water at a flow rate of 3 BV / h for 2 hours; Step 4: Desorb the above resin at room temperature using a mixed solution of 76 g / L NH4SCN (ammonium thiocyanate) and 6 g / L NaOH (sodium hydroxide). The circulating cleaning flow rate is 3 BV / h and the desorption time is 8 hours. Step 5: The activated carbon bed is pre-cleaned and activated with a 0.02g / ml NaOH (sodium hydroxide) solution. The desorption solution obtained in step 4 is circulated through the activated carbon adsorption column to obtain gold-loaded carbon and a desorption solution containing trace gold after adsorption. The gold-loaded carbon is desorbed and an electrolytic voltage of 2.8-4.5V is applied to the gold-containing desorption solution to obtain gold mud. Step 6: The resin obtained in step 4 is washed with a mixed solution of 152 g / L NH4SCN (ammonium thiocyanate) and 12 g / L NaOH (sodium hydroxide) at 58°C for 12 hours to obtain a gold-containing solution. A gold-containing solution is electrolytically applied at a voltage of 2.8-4.5 V to obtain gold mud. Step 7: Wash the resin obtained in step 6 with deionized water at a flow rate of 3 BV / h for 2 hours. Step 8: The resin obtained in step 7 was circulated and washed with 60 g / L sulfuric acid solution at a flow rate of 3 BV / h for 6 hours to obtain regenerated hydrogen-type (RH) resin; Step 9: Wash the resin with deionized water at a flow rate of 3 BV / h for 2 hours; Step 10: The resin obtained in step 9 was washed with 30 g / L sodium hydroxide solution at a flow rate of 3 BV / h for 6 hours to obtain a reusable OH-type resin.

[0050] The experimental results of Example 1 are shown in Table 3. Table 3 shows the results of preferential desorption of base metals from a strong base anion resin. The ppm in the table refers to 1 mg / L, which is a concentration unit. The % in the table represents weight percentage, i.e., the amount of Fe contained in 1 g of resin. The values ​​in the table represent the concentration of each metal in the resin after desorption with the corresponding reagent.

[0051] Table 3 As can be seen from Table 3, step 2 (acid wash) of Example 1 ultimately resolved >98% of zinc and >55% of nickel. Step 4 (alkaline ammonium thiocyanate solution) of Example 1 resolved >75% of copper, >80% of nickel, and >40% of cobalt; however, it also resolved approximately 25% of gold. Therefore, the solution obtained in step 4 required recovery of gold ions in step 5 (alkaline activated carbon).

[0052] Example 2 The steps of Example 2 are essentially the same as those of Example 1, except that the reagent in Step 4 is replaced with a mixed solution of 85 g / L NaNO3 (sodium nitrate) and 2 g / L NaOH (sodium hydroxide). The experimental results of Example 2 are shown in Table 4. The meanings of the various components of Table 4 are shown in Table 3.

[0053] Table 4 As can be seen in Table 4, the reagent used in step 4 of Example 2 ultimately desorbed >60% of copper, >45% of nickel, and >30% of cobalt, but almost no gold. Although the desorption rate of base metals from the reagent used in step 4 was lower than that of Example 1, the reagent used in step 4 is non-toxic and can be discharged directly into the tailings without the need to decompose the reagent before discharge.

[0054] Example 3 The steps of Example 3 are essentially the same as those of Example 1, except that the reagent in Step 4 is replaced with a mixed solution of 20 g / L NaCN (sodium cyanide) and 2 g / L NaOH (sodium hydroxide). The experimental results of Example 3 are shown in Table 5. The meanings of the various components of Table 5 are as shown in Tables 3 and 4.

[0055] Table 5 As can be seen from Table 5, the reagent in step 4 of Example 3 finally decomposed >75% of copper, but the decomposition rate of other base metals was low. Although the desorption rate of base metals other than copper by this reagent was low, the solution after decomposition can be used for carbon-in-slurry gold extraction operations, reducing the cost of the reagent.

[0056] Example 4 The following process is used to extract gold from a weakly alkaline anionic gold-loaded resin with low zinc content: Step 1: Load 100 ml of weak base anionic resin from the resin gold extraction system of the flotation concentrate of the Saipan mine high-pressure oxidation into the analytical column.

[0057] It should be pointed out that since the weak base anion resin has a weak adsorption capacity for zinc ions, the zinc ion content in the resin is not high, so the acidification zinc extraction step can be omitted (or not omitted) and the copper extraction stage can be directly entered; Step 2: The above resin was decomposed at room temperature using a mixed solution of 20 g / L NaCN (sodium cyanide) and 2 g / L NaOH (sodium hydroxide). The circulating cleaning flow rate was 3 BV / h and the decomposition time was 8 hours.

[0058] It should be pointed out that weak base resin has weak adsorption strength for metal cyanide complex ions, and copper can be decomposed with sodium cyanide without the need for alkaline ammonium thiocyanate solution. The benefit is that the cyanide-containing solution after sodium cyanide decomposition of the resin can be recycled for other stages of gold extraction.

[0059] Step 3: The activated carbon bed is pre-cleaned and activated with a 0.02g / ml NaOH (sodium hydroxide) solution. The desorption solution obtained in step 2 is circulated through the activated carbon adsorption column to obtain gold-loaded carbon and a desorption solution containing trace gold after adsorption. The gold-loaded carbon is desorbed and an electrolytic voltage of 2.8-4.5V is applied to the gold-containing desorption solution to obtain gold mud. Step 4: The resin obtained in step 2 is washed with a mixed solution of 152 g / L NH4SCN (ammonium thiocyanate) and 12 g / L NaOH (sodium hydroxide) at 58°C for 12 hours to obtain a gold-containing solution. A gold-containing solution is electrolytically processed at a voltage of 2.8-4.5 V to obtain gold mud. Step 5: Wash the resin obtained in step 4 with deionized water at a flow rate of 3 BV / h for 2 hours. Step 6: The resin obtained in step 5 was circulated and washed with 60 g / L sulfuric acid solution at a flow rate of 3 BV / h for 6 hours to obtain regenerated hydrogen-type (RH) resin; Step 7: Wash the above resin with deionized water at a flow rate of 3 BV / h for 2 hours; Step 8: The resin obtained in step 9 was washed with 30 g / L sodium hydroxide solution at a flow rate of 3 BV / h for 6 hours to obtain a reusable OH-type resin.

[0060] Example 5 The other process steps are the same as those in Example 4, except that the reagent in step 2 is replaced by a mixed solution of 5 g / L NaCN (sodium cyanide) and 2 g / L NaOH (sodium hydroxide), that is, the concentration of NaCN (sodium cyanide) is reduced.

[0061] Example 6 The other process steps are the same as those in Examples 4 and 5, except that the reagent in step 2 is replaced with a mixed solution of 1 g / L NaCN (sodium cyanide) and 2 g / L NaOH (sodium hydroxide), that is, the concentration of NaCN (sodium cyanide) is further reduced.

[0062] Example 7 The other process steps are the same as those of Examples 4, 5, and 6, except that the reagent in step 2 is replaced with a mixed solution of 0.5 g / L NaCN (sodium cyanide) and 0.5 g / L NaOH (sodium hydroxide), that is, the concentration of NaCN (sodium cyanide) is further reduced, and the concentration of NaOH (sodium hydroxide) is also reduced.

[0063] The experimental results for Examples 4-7 are shown in Table 6. Table 6 shows the results of preferential desorption of base metals from a weakly basic anionic resin. The ppm in the table refers to 1 mg / L, a unit of concentration. The % in the table represents weight percentage, i.e., the amount of Fe in 1 g of resin. The values ​​in the table represent the concentration of each metal in the resin after desorption with the corresponding reagent.

[0064] Table 6 As can be seen from Table 6, the alkaline sodium cyanide solution used in step 2 of Examples 4-7 effectively desorbs copper, with the desorption rate decreasing as the sodium cyanide concentration decreases. The desorption rates for other base metals are also low. Therefore, for weakly basic resins, alkaline sodium cyanide solution preferentially extracts copper, along with a small amount of gold, while minimizing the contamination of the desorption solution with other base metal ions.

[0065] This invention specifically targets the analysis of gold-loaded resins with high base metal contents. When the gold-loaded resin contains a large amount of copper, it can significantly reduce electrolytic energy consumption and equipment costs. The formula for calculating electrolytic energy consumption can be deduced based on Faraday's first law.

[0066] Faraday's first law can be expressed as: The meaning and units of each parameter are shown in Table 7: Table 7 Parameter definition The required electrolytic capacity is: in, is the charge, in coulombs.

[0067] According to the above formula, the electrolytic energy consumption required for traditional gold extraction and the electrolytic energy consumption required for the preferential analysis of base metals in the present invention can be calculated. See Table 8 for details.

[0068] Table 8 Electrolytic energy consumption Thus, the present invention can reduce electrolytic energy consumption by up to 50% or more for the decomposition of gold-loaded resins with high base metal content. It can also reduce electrolytic cell capacity by over 50%, significantly reducing equipment investment costs. This has significant economic value, especially for electrolytic cells and cathode and anode electrolytic plates made of corrosion-resistant titanium. Considering that electrolytic current efficiency is typically 30-60%, the present invention has even greater economic significance.

[0069] The above description is merely a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of the present invention is not limited to technical solutions formed by specific combinations of the above-mentioned technical features. It also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents, without departing from the above-mentioned disclosure. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A method for extracting gold from a gold-loaded resin containing base metals, characterized in that: The following steps are involved: Step 1: Use 50-150g / L hydrochloric acid or sulfuric acid solution to circulate and wash the gold-loaded resin containing base metals in the resin slurry gold extraction process for 4-12 hours at room temperature; Step 2: Use any of the following reagents to wash the gold-loaded resin after washing in step 1 for 4-12 hours at room temperature: Reagent 1: A mixed solution of 0.1-30g / L sodium cyanide and 0.5-5g / L sodium hydroxide; Reagent 2: a mixed solution of 20-100 g / L sodium nitrate and 0.5-5 g / L sodium hydroxide; Reagent 3: a mixed solution of 20-80 g / L thiocyanate and 0.5-5 g / L sodium hydroxide; Circulating the analytical solution through an activated carbon adsorption column to obtain gold-loaded carbon, analyzing the gold-loaded carbon to obtain a gold-containing analytical solution, and performing a first electrowinning treatment on the gold-containing analytical solution to obtain gold mud; Step 3: The gold-loaded resin washed in step 2 is circulated and washed with a mixed solution of 80-250 g / L thiocyanate and 5-25 g / L sodium hydroxide at 50-60° C. for 24-72 hours, and the resolved gold-containing precious liquid is subjected to a second electrowinning treatment to obtain gold mud; Step 4: Use 20-80g / L sulfuric acid or hydrochloric acid solution to wash the resin after the decomposition in step 3 for 4-12 hours; Step 5: The resin washed in step 4 is circulated and washed with 20-40 g / L sodium hydroxide solution for 4-12 hours to generate OH-type resin.

2. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: When the zinc content or nickel content of the gold-loaded resin is lower than a preset threshold, or when the gold-loaded resin is a weakly basic anion exchange resin, step 1 is omitted.

3. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: When the gold-loaded resin is a strongly basic anion exchange resin, the step 2 uses reagent 3.

4. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: Before the step 1, the method further includes: washing the gold-loaded resin with deionized water to remove ore particles in the resin.

5. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: The flow rate of the circulating washing in step 1 and step 2 is 2-4 BV / h.

6. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: Between step 1 and step 2, the resin is further washed with deionized water at a flow rate of 2-4 BV / h until the pH value of the resin is neutral; Between step 3 and step 4, the resin is washed with deionized water at a flow rate of 2-4 BV / h until the pH value of the resin is neutral.

7. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: Between step 4 and step 5, the resin is washed with deionized water at a flow rate of 2-4 BV / h until the pH value of the resin reaches 5-7.

8. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: The second step also includes: The activated carbon was pre-activated by 0.01-0.02 g / ml NaOH solution.

9. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: The cycle washing time of step 1 and step 2 is 6-8 hours.

10. The method for extracting gold from a gold-loaded resin containing base metals according to claim 1, characterized in that: The lean solution after the electrolytic deposition in step three is further used as the cleaning solution for the gold-loaded resin in step two.

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