Method for recovering gold from multi-metal complex acid solution system

Abstract

The embodiment of the invention provides a method for recovering gold from a multi-metal complex acid solution system, and the method comprises the following steps: pretreating a gold-containing complex acid solution, the pH value of the gold-containing complex acid solution is less than or equal to 4.5, and the gold content in the gold-containing complex acid solution ranges from 0.1 mg / L to 20 mg / L; an extraction agent is added into the gold-containing complex acid solution according to the extraction phase ratio O / A of 1: 20-1: 1, raffinate and a gold-loaded organic phase are obtained, and the extraction agent comprises one or more of ketone extraction agents such as methyl isobutyl ketone, dibutyl carbitol, trioctylamine, tribenzylamine and dimethyl sulfide, alcohol extraction agents, amine extraction agents and ether extraction agents; and separating and purifying gold in the gold-loaded organic phase to obtain a target gold product. The method is simple in process, easy to operate and low in cost, the high gold recovery rate can be obtained through primary extraction, efficient comprehensive utilization of gold in the gold smelting slag can be achieved, and environmental pollution is reduced.

Description

Technical Field

[0001] The disclosed embodiments belong to the field of metallurgical technology, and specifically relate to a method for recovering gold from a multi-metal complex acid solution system. Background Art

[0002] Gold is an important chemical element, widely used in aerospace, medical, chemical, science and technology, finance and other fields. It is an important strategic reserve material of the country and has an important position that cannot be replaced by other metals. With the decline of exploitable resources in domestic gold mines and the increasing proportion of imported raw materials, long-term dependence on imports will reduce the risk resistance of my country's gold industry, which is not conducive to the healthy development of the industry. At present, China's gold-producing enterprises are in urgent need of forming a new development model to recover and extract gold from more high-quality non-traditional gold-bearing materials.

[0003] The gold content in some gold-containing mining solid waste and electronic solid waste exceeds that of traditional minerals, but conventional beneficiation methods cannot effectively recover them. At present, they are still mainly in a stockpile state, causing serious environmental pollution and waste of resources. For example, gold smelting slag is one of them. Its stockpile volume and annual output are large, but due to its extremely fine particle size and severe mudification, conventional beneficiation methods are not effective. Through high-temperature chlorination roasting treatment, the gold in it can be formed into gold chloride, which volatilizes into the flue gas and then enters the eluent through spraying. However, other impurity metals in the gold-containing smelting slag, such as silver, copper, lead, zinc, etc., also enter the eluent. Subsequently, gold needs to be recovered from the gold-containing complex acidic eluent. During the investigation, it was found that although the valuable metals can basically achieve full volatilization in the chlorination roasting stage, the grade and recovery rate in the final product are not high, and a large part of the gold cannot be effectively extracted.

[0004] At the same time, with the accelerated development of science and technology, the frequency of electronic product replacement has increased, and the output of electronic solid waste has increased, but the recycling rate of electronic waste is very low, and the recycling cost is high and the efficiency is low. Aqua regia dissolution is an effective means of treating conventional electronic solid waste such as electronic circuit boards and CPUs. It can separate gold-containing materials from plastic carriers, epoxy resin boards, etc., but how to extract gold from the strong acid solution containing multiple metal ions in steps is still an important problem that needs to be solved.

[0005] The traditional technology for extracting gold from a solution system is mainly the cyanidation process. Due to the characteristics of the cyanidation process, it is necessary to ensure that the pH of the solution is maintained at about 11. Both the chlorination roasting eluent and the aqua regia solution contain a large number of impurity element ions such as copper, lead, zinc, tin, and iron. The pH adjustment process will produce a large amount of sediment, which will affect the cyanidation reaction and is not conducive to subsequent treatment. The conventional methods for extracting gold from an acidic solution system mainly include precipitation, direct reduction, activated carbon adsorption, metal replacement, and solvent extraction. The precipitation method is mainly based on sulfide precipitation, but the acidic solution system consumes a large amount of reagents, and H2S toxic gas will be generated during the precipitation reaction; the direct reduction method often uses oxalic acid or Na2SO3 as a reducing agent, and SO2 can also be directly introduced to reduce the chloroauric acid in the solution to elemental gold. There are also a large number of bubbles overflowing during the reaction, and improper operation is prone to danger; the activated carbon adsorption method and the metal replacement method have poor selectivity. While adsorbing or replacing gold, other metal elements such as silver, copper, lead, and zinc in the acid solution are also extracted together, and the subsequent separation and purification tasks are still heavy. Compared with various methods, solvent extraction has good selectivity, fast reaction speed, simple operation, and short cycle, and has incomparable advantages over other processes, but interference from other impurity elements must be avoided during the extraction process.

[0006] Therefore, how to recover gold from a complex multi-metal acidic solution system is a technical problem that needs to be solved urgently and has great practical significance. Summary of the invention

[0007] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a method for recovering gold from a multi-metal complex acidic solution system.

[0008] The present disclosure provides a method for recovering gold from a multi-metal complex acidic solution system, the method comprising:

[0009] Pretreating a gold-containing complex acidic solution, wherein the pH of the gold-containing complex acidic solution is ≤4.5, and the gold content in the gold-containing complex acidic solution is in the range of 0.1 mg / L to 20 mg / L;

[0010] According to the extraction phase ratio O / A=1:20-1:1, an extractant is added to the gold-containing complex acidic solution to obtain a raffinate and a gold-carrying organic phase, wherein the extractant includes one or more of ketone extractants such as methyl isobutyl ketone, dibutyl carbitol, trioctylamine, tribenzylamine, dimethyl sulfide, alcohol extractants, amine extractants, and ether extractants;

[0011] The gold in the gold-loaded organic phase is separated and purified to obtain a target gold product.

[0012] Optionally, the extractant is an organic solution formed by compounding the dibutyl carbitol and the trioctylamine in a volume ratio of 1:1 to 1:10.

[0013] Optionally, the extractant is an organic solution formed by compounding the methyl isobutyl ketone and the dibutyl carbitol in a volume ratio of 1:1 to 1:5.

[0014] Optionally, the concentration range of the extractant added to the gold-containing complex acidic solution is 40% to 100%.

[0015] Optionally, the step of adding an extractant to the gold-containing complex acidic solution to obtain a raffinate and a gold-loaded organic phase comprises:

[0016] The gold-containing complex acidic solution to which the extractant is added is placed in an oscillator at a temperature range of 15° C. to 70° C., and oscillated at an oscillation frequency of 1600 r / min for 5 min to 120 min;

[0017] The oscillated solution is statically layered to obtain the raffinate and the gold-loaded organic phase, respectively.

[0018] Optionally, separating and purifying the gold in the gold-loaded organic phase comprises:

[0019] The gold in the gold-carrying organic phase is separated and purified by a stripping method, which specifically includes:

[0020] An oxalic acid solution with a concentration of 30 g / L to 90 g / L is prepared as a stripping agent, and the stripping agent is added to the gold-carrying organic phase to obtain a gold-containing solution, wherein the extraction phase ratio O / A is 1:1 to 20:1;

[0021] The gold-containing solution is oscillated at an oscillation frequency of 1600 r / min for 5 to 60 min;

[0022] The gold-containing solution after shaking is heated and boiled for 30 to 120 minutes to precipitate gold at the bottom of the solution;

[0023] The gold-containing solution is sequentially cooled, filtered, washed and dried to obtain the target gold product.

[0024] Optionally, the separation and purification of gold in the gold-loaded organic phase further comprises:

[0025] The gold in the gold-carrying organic phase is separated and purified by a direct reduction method, which specifically includes:

[0026] Using one of oxalic acid, a sulfiding agent or a polysulfide as a precipitant, and adding an excess of 5% to 50% of the precipitant into the gold-carrying organic phase and stirring to obtain a gold-containing precipitation solution;

[0027] The gold-containing precipitation solution is washed and roasted in sequence to obtain the target gold product.

[0028] Optionally, after adding the extractant to the gold-containing complex acidic solution to obtain a raffinate and a gold-loaded organic phase, the method further comprises:

[0029] Other metal ions in the raffinate are further separated and extracted to obtain corresponding metal elements.

[0030] Optionally, the gold-containing complex acidic solution includes a chlorination roasting eluent and an aqua regia acid solution.

[0031] Optionally, the gold-containing complex acidic solution has a silver content in the range of 0.1 mg / L to 200 mg / L, a copper content in the range of 0.1% to 10%, a lead content in the range of 0.1% to 10%, and a zinc content in the range of 0.1% to 50%.

[0032] The method for recovering gold from a multi-metal complex acidic solution system of the disclosed embodiment is for a complex acidic solution system containing multiple metals. It is not necessary to adjust the pH value of the solution. A suitable extractant is selected and added to the gold-containing complex acidic solution. The gold in the gold-containing complex acidic solution can be directly extracted into the gold-carrying organic phase, and the extraction rate can reach 99%; the selected extractant only has an extraction effect on gold, and has no extraction effect on other impurity metals. The gold purity in the obtained gold-carrying organic phase is high, the gold content in the gold-carrying organic phase can be enriched by more than 100 times, and the impurity content is extremely small, and the overall recovery rate of gold is more than 98%; the gold in the gold-carrying organic phase is separated and purified to obtain a better sponge gold product with bright color and purity ≥95%. The method for recovering gold has guiding significance for the recovery of gold in complex acidic solution systems with other similar components.

[0033] In the method for recovering gold from a complex acidic solution system containing multiple metals according to the embodiment of the present disclosure, the extractants used in the extraction process can be returned for reuse, no toxic or harmful gases or liquids are discharged, the method is efficient and environmentally friendly, and pollution to the environment is reduced; gold can be recovered from a complex acidic solution containing multiple metal elements using a small amount of extractant, and the recovery rate is higher.

[0034] The method for recovering gold from a multi-metal complex acidic solution system of the embodiment of the present disclosure has a simple process, is easy to operate, and has low cost. A high gold recovery rate can be obtained by performing a primary extraction, and efficient and comprehensive utilization of gold in gold smelting slag can be achieved, thereby reducing environmental pollution caused by the storage of gold smelting slag and increasing the economic benefits of gold smelting enterprises.

[0035] The method for recovering gold from a multi-metal complex acid solution system of the disclosed embodiment can solve the problem of recovering gold from the leaching liquid after chlorination roasting-spraying of gold-containing waste slag and other mining solid wastes, and the problem of extracting gold from a variety of impurity metal solutions generated after electronic solid wastes are dissolved in aqua regia. On the one hand, it can reduce the environmental pollution hazards caused by large-scale gold-containing solid wastes, and on the other hand, it can recover the valuable elements therein, creating economic benefits for enterprises. The initial realization of the purpose of efficiently recovering gold from mining solid wastes and electronic solid wastes, the expansion of new gold-producing raw materials, is conducive to the achievement of my country's "dual carbon" goals, and enables my country to get rid of the dilemma of long-term dependence on traditional mines and imported resources for gold-producing raw materials, and promote the leapfrog development of my country's gold industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a schematic flow chart of a method for recovering gold from a multi-metal complex acid solution system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the embodiments of the present disclosure are further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] like Figure 1 As shown, the embodiment of the present disclosure provides a method S100 for recovering gold from a multi-metal complex acidic solution system, and the method S100 comprises:

[0039] S110. Pretreating the gold-containing complex acidic solution, wherein the pH of the gold-containing complex acidic solution is ≤4.5, and the gold content in the gold-containing complex acidic solution is in the range of 0.1 mg / L to 20 mg / L.

[0040] Specifically, in this embodiment, the gold-containing complex acidic solution is a solution containing gold, silver, copper,

[0041] The pH of complex strong acid solutions of lead, zinc, iron and other metals and complex acid solutions containing gold is ≤

[0042] 4.5. The gold content in the gold-containing complex acid solution ranges from 0.1mg / L to 20mg / L, the silver content ranges from 0.1mg / L to 200mg / L, the copper content ranges from 0.1% to 10%, the lead content ranges from 0.1% to 10%, and the zinc content ranges from 0.1% to 50%. Among them, the gold-containing complex acid solution mainly includes the chlorination roasting leaching liquid after chlorination roasting-spraying of gold-containing waste slag and other mining solid wastes and the aqua regia acid solution after electronic solid wastes are dissolved in aqua regia. These two solutions are strong acid solutions and contain a variety of impurity metals.

[0043] Among them, the pretreatment of the gold-containing complex acidic solution is mainly to filter out the insoluble impurities in the gold-containing complex acidic solution.

[0044] S120. According to the extraction phase ratio O / A=1:20 to 1:1, an extractant is added to the gold-containing complex acidic solution to obtain a raffinate and a gold-loaded organic phase, wherein the extractant includes one or more of ketone extractants such as methyl isobutyl ketone, dibutyl carbitol, trioctylamine, tribenzylamine, dimethyl sulfide, etc., alcohol extractants, amine extractants, and ether extractants.

[0045] Wherein, step S120 may specifically include:

[0046] First, apply a layer of grease (such as Vaseline) on the piston core of the 100ml pear-shaped separatory funnel, then insert the plug core into the piston, rotate it several times to evenly distribute the grease, then close the piston, and put a rubber ring of appropriate diameter on the groove of the plug core to prevent the piston core from loosening or falling off during the oscillation process, resulting in leakage and causing experiment failure.

[0047] Secondly, take a certain amount of gold-containing complex acid solution (aqueous phase) and 40% to 100% concentration of extractant (organic phase), mix them according to the extractant ratio O / A = 1:20 to 1:1, pour them into a separatory funnel, and fasten the glass stopper. The extractant can be composed of one or more of a complexing agent, a diluent, and a cosolvent.

[0048] Among them, in this embodiment, the extractant includes one or more of ketone extractants such as methyl isobutyl ketone, dibutyl carbitol, trioctylamine, tribenzylamine, dimethyl sulfide, alcohol extractants, amine extractants, and ether extractants.

[0049] It should be noted that this embodiment does not specifically limit which extractant to use and which extractants to mix, and can be selected according to actual needs.

[0050] In this embodiment, a suitable extractant is selected and added to the gold-containing complex acidic solution, so that the gold in the gold-containing complex acidic solution can be directly extracted into the gold-loaded organic phase, and the extraction rate can reach 99%; the selected extractant only has an extraction effect on gold, and has no extraction effect on other impurity metals. The gold purity in the obtained gold-loaded organic phase is relatively high, the gold content in the gold-loaded organic phase can be enriched by more than 100 times, and the impurity content is extremely small, and the overall recovery rate of gold is above 98%.

[0051] Next, the separating funnel was placed in a CHA-S digital air bath constant temperature oscillator which had reached a preset temperature (15°C to 70°C) and oscillated at an oscillation frequency of 1600 r / min for 5 min to 120 min.

[0052] Finally, the oscillated separating funnel is placed on a funnel stand to allow the solution to stand and separate into layers. After stabilization, the raffinate (aqueous phase) and the gold-loaded organic phase can be obtained by separation.

[0053] In this embodiment, the principle of extracting gold from a complex acidic solution containing gold using an extractant is:

[0054] Through chlorination roasting or aqua regia leaching, gold is mainly present in the acid solution as the coordinated anion AuCl4 - It exists in the form of ions. If a suitable extractant is selected, it can form an ion-associated complex and enter the organic phase. The chemical reaction equation is as follows:

[0055] R + +AuCl - 4→R + ·AuCl - 4.

[0056] The extractant selected in this embodiment has an extraction effect only on gold, and has no extraction effect on other impurity metals. The gold purity in the obtained gold-loaded organic phase is relatively high. Gold can be recovered from a complex acidic solution containing multiple metal elements using a small amount of extractant, and the recovery rate is higher.

[0057] It should be noted that after obtaining the raffinate, other metal ions in the raffinate can be further separated and extracted to obtain other metal elements such as silver, copper, lead, zinc, etc., thereby realizing the recovery of other elements.

[0058] Preferably, the extractant may be an organic solution formed by compounding the dibutyl carbitol and the trioctylamine in a volume ratio of 1:1 to 1:10.

[0059] Further preferably, the extractant may also be an organic solution formed by compounding the methyl isobutyl ketone and the dibutyl carbitol in a volume ratio of 1:1 to 1:5.

[0060] In this embodiment, the extraction effect of using a compound extractant is better than that of using a single extractant, which saves dosage and economic costs.

[0061] S130, separating and purifying the gold in the gold-loaded organic phase to obtain a target gold product.

[0062] In the embodiments of the present disclosure, the gold in the gold-loaded organic phase can be separated and purified by a stripping method or a direct reduction method.

[0063] Wherein, the gold in the gold-carrying organic phase is separated and purified by a stripping method, which specifically includes:

[0064] First, an oxalic acid solution with a concentration of 30 g / L to 90 g / L is prepared as a stripping agent, and the stripping agent is added to the gold-loaded organic phase to obtain a gold-containing solution, wherein the extraction phase ratio O / A is 1:1 to 20:1.

[0065] Secondly, the gold-containing solution is oscillated at an oscillation frequency of 1600 r / min for 5 to 60 minutes.

[0066] Next, the gold-containing solution after shaking is heated and boiled for 30 to 120 minutes to precipitate gold at the bottom of the solution;

[0067] Finally, the gold-containing solution is cooled, filtered, washed and dried in sequence to obtain a sponge gold product with bright color and good purity, wherein the final product rate of sponge gold is ≥95%.

[0068] Wherein, the gold in the gold-carrying organic phase is separated and purified by a direct reduction method, which specifically includes:

[0069] Firstly, one of oxalic acid, sulfiding agent or polysulfide is used as a precipitant, the amount of the precipitant is calculated according to the chemical reaction formula, and an excess of 5% to 50% of the precipitant is added to the gold-carrying organic phase, and the solution is stirred to accelerate the reaction to obtain a gold-containing precipitation solution.

[0070] Secondly, the gold-containing precipitation solution is washed and roasted in sequence to remove elements such as S, C, and O, thereby obtaining a sponge gold product with a purity of ≥95%.

[0071] It should be noted that the various indicators in the method for recovering gold from a multi-metal complex acidic solution system are: the extraction rate can reach 99%, the stripping rate can reach 99%, the overall recovery rate of gold is ≥98%, and finally a sponge gold product with bright color and good indicators can be obtained, and the final product rate of sponge gold is ≥95%.

[0072] The method for recovering gold from a multi-metal complex acidic solution system according to the embodiment of the present disclosure has the following advantages compared to other existing methods for extracting gold from gold-containing acidic solutions:

[0073] 1) The object of gold recovery is a complex acidic solution containing multiple metals, mainly including the chlorination roasting elution solution containing gold-containing solid waste, or the other impurity metals such as silver, copper, lead, zinc, iron, etc. produced after the electronic waste is dissolved in aqua regia, which has a certain impact on the extraction of gold. The embodiment of the present disclosure is aimed at a complex acidic solution system containing multiple metals. There is no need to adjust the pH value of the solution. A suitable extractant is selected and added to the complex acidic solution containing gold. The gold in the complex acidic solution containing gold can be directly extracted into the gold-carrying organic phase, and the extraction rate can reach 99%, which has guiding significance for the treatment of complex acidic solutions with similar components.

[0074] 2) The selected extractant only has an extraction effect on gold, but has no extraction effect on other impurity metals, and the obtained gold-loaded organic phase has a higher purity.

[0075] 3) The extraction effect of using a compound extractant is better than that of using a single extractant, which saves dosage and economic costs.

[0076] 4) Gold can be extracted from the gold-loaded organic phase by stripping or direct reduction, and a better sponge gold product with bright color and purity ≥95% can be obtained.

[0077] 5) The extractants used in the extraction process can be returned for reuse, and no toxic or harmful gases or liquids are discharged.

[0078] 6) The process is simple, easy to operate, and low in cost. A high gold recovery rate can be obtained by performing a primary extraction, which can realize the efficient and comprehensive utilization of gold in gold smelting slag, reduce environmental pollution caused by the storage of gold smelting slag, and increase the economic benefits of gold smelting enterprises.

[0079] The specific process of a method for recovering gold from a multi-metal complex acidic solution system according to an embodiment of the present disclosure is further illustrated below through several specific examples.

[0080] Embodiment 1:

[0081] Gold smelting slag from a certain place in Henan Province was subjected to high-temperature chlorination roasting at 1100°C for 60 minutes in a rotary kiln. The smoke was collected by subsequent wet dust collection equipment to obtain an acidic leaching liquid with an Au content of 1.21 mg / L. The main valuable metal contents are shown in Table 1.

[0082] Table 1 Multi-element analysis results of gold smelting slag

[0083]

[0084] Note: * represents the unit (mg / L); other units are (%)

[0085] Dibutyl carbitol was selected as the extractant, and sulfonated kerosene was selected as the diluent when preparing a certain concentration of extractant solution. A certain amount of eluent (aqueous phase) and 90% dibutyl carbitol were taken as the extractant (organic phase), mixed according to the extractant ratio O / A=1:4, poured into a 100ml pear-shaped separatory funnel, fastened the glass stopper, and placed in a CHA-S digital air bath constant temperature oscillator at 25°C for oscillation, and the oscillation frequency was set to 1600r / min. After 10 minutes of oscillation, take it out and place the separatory funnel on the funnel stand to allow the solution to stand and separate. After stabilization, the raffinate (aqueous phase) and the gold-carrying organic phase can be obtained by separation. The gold concentration in the raffinate was analyzed and detected, and the gold extraction rate was calculated by subtraction method according to formula (2).

[0086]

[0087] Where E is the gold extraction rate; α is the gold concentration in the original solution; β is the gold concentration in the raffinate.

[0088] The first-stage extraction can make the Au extraction rate in the high-temperature chlorination roasting eluent of gold smelting slag reach 96.54%, and then use an excess of 10% oxalic acid to strip the gold in the gold-carrying organic phase to obtain a qualified sponge gold product. This process technology provides an effective method for separating and extracting gold from acidic solutions with complex components and more impurities.

[0089] Embodiment 2:

[0090] Gold smelting slag from a certain place in Shandong Province was subjected to high-temperature chlorination roasting at 1150°C for 50 minutes in a rotary kiln. The smoke was collected by subsequent wet dust collection equipment to obtain an acidic leaching liquid with an Au content of 2.32 mg / L. The main valuable metal contents are shown in Table 2.

[0091] Table 2 Multi-element analysis results of gold smelting slag

[0092]

[0093] Note: * represents the unit (mg / L); other units are (%)

[0094] An organic solution formed by compounding methyl isobutyl ketone and dibutyl carbitol in a volume ratio of 1:2 is selected as the extractant. Under the conditions of an extractant concentration of 80%, an extractant ratio of O / A=1:6, and extraction for 10 minutes at room temperature, a primary extraction can achieve an Au extraction rate of 99.23% in the high-temperature chlorination roasting eluent of gold smelting slag. Then, an excess of 30% oxalic acid is used to strip the gold in the gold-loaded organic phase to obtain a qualified sponge gold product. This process technology can provide an effective method for separating and extracting gold from an acidic solution with complex components and more impurities.

[0095] Embodiment 3:

[0096] Gold smelting slag from a certain place in Hunan was subjected to high-temperature chlorination roasting at 1100℃ for 60min in a rotary kiln. The smoke was collected by subsequent wet dust collection equipment to obtain an acidic leaching liquid with an Au content of 5.52mg / L. The main valuable metal contents are shown in Table 3.

[0097] Table 3 Multi-element analysis results of gold smelting slag

[0098]

[0099] Note: * represents the unit (mg / L); other units are (%)

[0100] Using dibutyl carbitol organic solution as the extractant, the concentration of the extractant is 60%, the extraction phase ratio O / A=1:10, and the extraction time is 20 minutes at room temperature. The first-stage extraction can make the Au extraction rate in the high-temperature chlorination roasting eluent of gold smelting slag reach 97.41%. Then, the gold in the gold-carrying organic phase is stripped with an excess of 15% oxalic acid to obtain a qualified sponge gold product. This process technology provides an effective method for separating and extracting gold from acidic solutions with complex components and more impurities.

[0101] Embodiment 4:

[0102] The CPU disassembled from a waste circuit board was leached with aqua regia to obtain an acid solution with an Au content of 20.74 mg / L. The main valuable metal contents are shown in Table 4.

[0103] Table 4 Multi-element analysis results of gold smelting slag

[0104]

[0105] Note: * represents the unit (mg / L); other units are (%)

[0106] Using trioctylamine as the extractant, the extraction rate of Au in the acid solution can reach 95.86% by performing primary extraction at the conditions of 85% extractant concentration, extraction phase ratio O / A=1:6, and extraction for 15 minutes at room temperature. Then, using excess 70% oxalic acid to back-extract the gold in the gold-loaded organic phase, a qualified sponge gold product can be obtained. This process technology provides an effective method for separating and extracting gold from acidic solutions with complex components and more impurities.

[0107] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the embodiments of the present disclosure, but the embodiments of the present disclosure are not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the embodiments of the present disclosure, and these modifications and improvements are also considered to be within the protection scope of the embodiments of the present disclosure.

Claims

1. A method for recovering gold from a multi-metal complex acidic solution system, characterized in that: The method comprises: Pretreating a gold-containing complex acidic solution, wherein the pH of the gold-containing complex acidic solution is ≤4.5, and the gold content in the gold-containing complex acidic solution is in the range of 0.1 mg / L to 20 mg / L; According to the extraction phase ratio O / A=1:20-1:1, an extractant is added to the gold-containing complex acidic solution to obtain a raffinate and a gold-carrying organic phase, wherein the extractant includes one or more of ketone extractants such as methyl isobutyl ketone, dibutyl carbitol, trioctylamine, tribenzylamine, dimethyl sulfide, alcohol extractants, amine extractants, and ether extractants; The gold in the gold-loaded organic phase is separated and purified to obtain a target gold product.

2. The method according to claim 1, characterized in that: The extractant is an organic solution formed by compounding the dibutyl carbitol and the trioctylamine in a volume ratio of 1:1 to 1:

10.

3. The method according to claim 1, characterized in that The extractant is an organic solution formed by compounding the methyl isobutyl ketone and the dibutyl carbitol in a volume ratio of 1:1 to 1:

5.

4. The method according to any one of claims 1 to 3, characterized in that: The concentration range of the extractant added to the gold-containing complex acidic solution is 40% to 100%.

5. The method according to any one of claims 1 to 3, characterized in that: The step of adding an extractant to the gold-containing complex acidic solution to obtain a raffinate and a gold-carrying organic phase comprises: The gold-containing complex acidic solution to which the extractant is added is placed in an oscillator at a temperature range of 15° C. to 70° C., and oscillated at an oscillation frequency of 1600 r / min for 5 min to 120 min; The oscillated solution is statically layered to obtain the raffinate and the gold-loaded organic phase, respectively.

6. The method according to any one of claims 1 to 3, characterized in that: The step of separating and purifying the gold in the gold-carrying organic phase comprises: The gold in the gold-carrying organic phase is separated and purified by a stripping method, which specifically includes: An oxalic acid solution with a concentration of 30 g / L to 90 g / L is prepared as a stripping agent, and the stripping agent is added to the gold-carrying organic phase to obtain a gold-containing solution, wherein the extraction phase ratio O / A is 1:1 to 20:1; The gold-containing solution is oscillated at an oscillation frequency of 1600 r / min for 5 to 60 min; The gold-containing solution after shaking is heated and boiled for 30 to 120 minutes to precipitate gold at the bottom of the solution; The gold-containing solution is sequentially cooled, filtered, washed and dried to obtain the target gold product.

7. The method according to any one of claims 1 to 3, characterized in that: The separation and purification of gold in the gold-loaded organic phase also includes: The gold in the gold-carrying organic phase is separated and purified by a direct reduction method, which specifically includes: Using one of oxalic acid, a sulfiding agent or a polysulfide as a precipitant, and adding an excess of 5% to 50% of the precipitant into the gold-carrying organic phase and stirring to obtain a gold-containing precipitation solution; The gold-containing precipitation solution is washed and roasted in sequence to obtain the target gold product.

8. The method according to any one of claims 1 to 3, characterized in that: After adding the extractant to the gold-containing complex acidic solution to obtain a raffinate and a gold-carrying organic phase, the method further comprises: Other metal ions in the raffinate are further separated and extracted to obtain corresponding metal elements.

9. The method according to any one of claims 1 to 3, characterized in that: The gold-containing complex acidic solution comprises a chlorination roasting eluent and an aqua regia acid solution.

10. The method according to any one of claims 1 to 3, characterized in that: The gold-containing complex acidic solution has a silver content ranging from 0.1 mg / L to 200 mg / L, a copper content ranging from 0.1% to 10%, a lead content ranging from 0.1% to 10%, and a zinc content ranging from 0.1% to 50%.

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