Extraction and recovery method of metal resources

Abstract

An extraction and recovery method of metal resources comprises the steps that raw materials containing valuable metal are soaked in an amino complexing agent solution with low CO2 loading capacity for a leaching reaction, target metal ions are transferred from a solid phase to a liquid phase, and a solution containing a complex of the target metal ions is obtained; after the solution containing the target metal ion complex is purified and subjected to impurity removal, the solution and industrial flue gas containing CO2 are subjected to gas-liquid contact, flue gas CO2 trapping is achieved, high-purity CO2 is further introduced to form a reaction system with the high CO2 loading capacity, a metal ion carbonation precipitation reaction is conducted, and a metal product is obtained after filtering; and heating the filtered solution to a certain temperature, carrying out CO2 desorption reaction under a certain pressure to realize regeneration of the amino complexing agent and recycling of CO2, and using the regenerated amino complexing agent for metal ion leaching so as to complete recycling of the amino complexing agent. The extraction and recovery method provides a new technical choice for extraction of metal ore resources and recycling and low-carbon utilization of valuable metal wastes.

Description

Technical Field

[0001] The invention relates to the technical field of metal resource extraction and waste metal resource recycling, and more specifically, to a method for extracting and recycling metal resources. Background Art

[0002] Existing metal extraction and recovery technologies mainly include pyrometallurgy, hydrometallurgy and a combination of the two. The pyrometallurgical process is relatively simple, but it has problems such as high energy consumption and waste gas pollution. Hydrometallurgy generally recovers valuable metals through low-temperature leaching and subsequent separation and purification. Solutions rich in various valuable metals are further used to generate new materials or high value-added products through various methods. Among them, acid hydrometallurgy and alkaline hydrometallurgy are the two main types. Acid hydrometallurgy usually first dissolves minerals or waste containing valuable metals with acid to leach valuable metal elements, and then separates and purifies valuable metals through chemical precipitation and extraction. Acid hydrometallurgy technology is a common method for metal extraction and recovery in industry today, and has the following advantages: (1) mature process and low energy consumption; (2) high purity of recovered products, a large number of high value-added products, and a high recovery rate. However, this technology also has several unavoidable problems. The use of large amounts of chemical reagents such as acids and extractants produces a large amount of wastewater, resulting in high secondary pollution treatment costs, which seriously affects the economic viability of scrap metal recycling projects. The acid leaching process lacks selectivity for metal ions, which complicates the subsequent metal ion separation and purification process.

[0003] In recent years, alkaline hydrometallurgy has also attracted more and more attention. Patent CN108950184A discloses a method for recovering zinc from zinc ferrite resources by using magnetization roasting-ammonia leaching. By roasting in a reducing atmosphere, the structurally stable zinc ferrite is converted into zinc oxide and magnetite, and then the zinc oxide is selectively dissolved by ammonia leaching. Patent US6524367 discloses a method of using NH 3 -(NH 4 ) 2 CO 3A method for leaching cobalt ions and nickel ions from minerals and further separating them. The main process of alkaline hydrometallurgy is ammonia leaching, and its main working principle is to utilize the selective complexation of metal ions with ammonia molecules to transfer them from the solid phase to the liquid phase. The main advantage of ammonia leaching is that it has a certain selectivity for metal ion leaching, and after the ammonia-containing solution is used, the ammonia water can be reapplied to the metal ion ammonia leaching process by adjusting the pH, ammonia evaporation and other process methods to achieve the recycling of ammonia water. However, there are still a series of problems in the ammonia leaching process, such as high energy consumption in the process of ammonia evaporation; the introduction of reducing agents complicates the process and increases the process cost; there are certain limitations on the selectivity of metal ion leaching, and the metal ion products after purification require complex subsequent processing steps. Therefore, providing a method for metal resource extraction and recovery that can directly generate high-purity products in the leaching process, the solvent can be recycled in a closed loop, and the process is simple has become a technical problem that needs to be solved by technicians in this field. Summary of the invention

[0004] In view of the drawbacks of the existing methods for extracting and recovering metal resources, such as complex process, high recovery cost and secondary pollution, the purpose of the present invention is to provide a metal complex leaching-CO 2 A method for extracting and recovering metal resources by mineralization precipitation-complexing agent regeneration and reuse, realizing the recycling of chemical reagents in the process and the removal of greenhouse gas CO in the waste gas 2 resource utilization.

[0005] The present invention provides a method for extracting and recovering metal resources, comprising the following steps:

[0006] a) Soak the raw materials containing valuable metals in low CO 2 In a solution of a loaded amount of an amine-based complexing agent, a leaching reaction is carried out to transfer the target metal ions from a solid phase to a liquid phase, thereby obtaining a solution containing a target metal ion complex;

[0007] b) purifying and removing impurities from the solution containing the target metal ion complex obtained in step a) and mixing with the solution containing CO 2 The industrial flue gas is contacted with gas and liquid to achieve flue gas CO 2 Capture, and on this basis, further introduce high-purity and high-pressure CO 2 Formation of high CO 2 The reaction system with a high loading amount is subjected to a carbonation precipitation reaction of metal ions, and a metal product is obtained after filtration.

[0008] Preferably, the raw material containing valuable metals in step a) is primary mineral resources or waste containing valuable metals; wherein the metals include one or more of gold, silver, copper, zinc, lithium, cobalt, nickel, manganese, cadmium and chromium.

[0009] Preferably, the amine complexing agent solution in step a) is selected from one or more of aqueous ammonia, organic amine solution, amino acid solution, and ammonium bicarbonate solution;

[0010] The low CO 2 The loading capacity refers to the total CO in the solution. 2 Molar concentration (including free CO 2 The ratio of the molar concentration of the amine complexing agent to the molar concentration of the amine complexing agent is less than or equal to 0.5. Preferably, CO 2 The load value is 0.2~0.4.

[0011] Preferably, the leaching reaction temperature in step a) is 60° C. to 150° C., the time is 1 h to 8 h, the solid-liquid ratio is 10 g / L to 100 g / L, and the stirring speed is 300 rpm to 600 rpm.

[0012] Preferably, in step b), the 2 CO in industrial flue gas 2 The concentration of the solution is 1% to 95%, and further 4% to 30%. 2 After full reaction, CO 2 The load increases to above 0.5.

[0013] Preferably, in step b), the high CO 2 The load is greater than or equal to 0.7.

[0014] Preferably, the temperature of the precipitation reaction in step b) is 20°C to 100°C, further 60°C to 90°C, and the reaction time is 1h to 12h, further 4h to 8h.

[0015] Preferably, it also includes:

[0016] c) The high CO obtained after filtration 2 The filtrate with a certain amount of loading is sent to the distillation tower for CO 2 Desorption and amine complexing agent regeneration to obtain high-purity CO 2 and low CO 2 Loading amount of amine complexing agent solution.

[0017] Preferably, in step c), a reboiler is provided at the bottom of the distillation tower to provide the heat required for the regeneration of the amine-based complexing agent, and a condenser is provided at the top to cool the temperature of the regenerated gas from the distillation tower, and the condensed liquid phase is refluxed to the distillation tower body to obtain a low CO 2 The loaded amine complexing agent solution, the gas phase is high-purity CO 2 .

[0018] Preferably, in step c), the reboiler temperature is 80°C to 150°C, further 110°C to 130°C; the pressure is 1 bar to 5 bar, further 1 bar to 3 bar; and the condenser temperature is 20°C to 60°C, further 35°C to 45°C.

[0019] Compared with the prior art, the metal resource extraction and recovery method provided by the present invention adopts specific process steps and has the following technical characteristics: (1) using an amine complexing agent as a link to selectively leach metals with high efficiency; (2) using an amine complexing agent to react with CO 2 The characteristics of the reaction can achieve the dual benefits of industrial flue gas decarbonization and efficient precipitation and separation of metal ions; (3) using amino complexing agents and CO 2 The reversibility of the reaction enables the complexing agent and high-purity CO 2 The present invention provides a new technical option for the extraction of metal ore resources and the resource and low-carbon utilization of valuable metal waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a process flow chart of the method for extracting and recovering metal resources provided by the present invention. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be clearly and completely described below in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present invention provides a method for extracting and recovering metal resources, comprising the following steps:

[0023] a) Soak the raw materials containing valuable metals in low CO 2 In the loaded amine complexing agent solution, a leaching reaction is carried out to transfer the target metal ions from the solid phase to the liquid phase to obtain a solution containing the target metal ion complex.

[0024] b) purifying and removing impurities from the solution containing the target metal ion complex obtained in step a) and mixing with the solution containing CO 2 The industrial flue gas is contacted with gas and liquid to achieve flue gas CO 2 Capture, and on this basis, further introduce high-purity and high-pressure CO 2 Formation of high CO 2 The reaction system with a high loading amount is subjected to a carbonation precipitation reaction of metal ions, and a metal product is obtained after filtration.

[0025] c) filtering the high CO obtained in step b)2 The loaded filtrate is sent to the distillation tower and CO is removed at a certain temperature and pressure. 2 Desorption and amine complexing agent regeneration to obtain high-purity CO 2 and low CO 2 The regenerated amine complexing agent is used for the metal ion leaching in the next cycle of step a), and the high-purity CO 2 Used for metal precipitation in the next cycle, thus completing the amine complexing agent and high-purity CO 2 of recycling.

[0026] The present invention provides an efficient, environmentally friendly, green and low-carbon method for extracting and recycling metal resources. Figure 1 , Figure 1 This is a process flow chart of the method for extracting and recovering metal resources provided by the present invention.

[0027] The present invention first performs a metal complex leaching step: immersing the raw material containing valuable metals in a low CO 2 In the loaded amine complexing agent solution, a leaching reaction is carried out to transfer the target metal ions from the solid phase to the liquid phase to obtain a solution containing the target metal ion complex.

[0028] In the present invention, the raw material containing valuable metals is preferably primary ore resources or waste containing valuable metals; wherein the metal preferably includes one or more of gold, silver, copper, zinc, lithium, cobalt, nickel, manganese, cadmium, and chromium. In a preferred embodiment of the present invention, the raw material containing valuable metals is waste ternary lithium batteries, zinc-containing waste residues, and copper-containing waste (copper-containing sludge), wherein the waste ternary lithium batteries are preferably subjected to reduction roasting to obtain waste ternary lithium battery positive electrode powder before the extraction and recovery of metal resources.

[0029] In the present invention, the amine-based complexing agent refers to an amine-based chemical substance that can undergo a selective complexing reaction with metal ions, including ammonia water, organic amines, amino acids, etc. In the present invention, the amine-based complexing agent solution is preferably selected from one or more of ammonia water, organic amine solution, amino acid solution, and ammonium bicarbonate solution, and is more preferably an ethanolamine solution, or a mixed solution formed by an ammonia solution and ammonium bicarbonate solution; the present invention has no special restrictions on the source of the amine-based complexing agent solution, and commercial products or self-made products well known to those skilled in the art can be used. In the present invention, the concentration of the amine-based complexing agent solution is 1mol / L to 6mol / L, preferably 2mol / L to 3mol / L.

[0030] In the present invention, the low CO 2 The loading amount is preferably less than or equal to 0.5; wherein, CO 2 Loading refers to the presence of amine complexing agent and CO in the solution. 2The reaction product mainly comprises free amine leaching agent, protonated amine leaching agent, carbamate, bicarbonate and carbonate, wherein the active component which reacts with metal ions in complexation is the free amine leaching agent.

[0031] Under certain leaching conditions such as temperature and reaction time, the present invention transfers the target metal ions from the solid phase to the liquid phase through a selective complexing reaction between the complexing leaching agent and the target metal ions, thereby obtaining a solution containing the target metal ion complex, and impurity metals such as Fe and Al remain in the residue as a waste residue discharge system.

[0032] The target metal oxide (Me 2 O x ) and organic amine complexing agent (R 1 R 2 R 3 N) as an example, the metal selective complex leaching reaction is shown in formula (1):

[0033] 2n 1 R 2 R 3 N+Me 2 O x +xH 2 O→2[Me(R 1 R 2 R 3 N) n ] x+ +2xOH - (1);

[0034] Among them, R 1 , R 2 , R 3 They are respectively one of C1-C6 alkyl, C1-C6 hydroxyl, C1-C6 amine, C1-C6 carbonyl, C1-C6 carboxyl, hydrogen atom and the like.

[0035] In the present invention, the leaching reaction temperature is preferably 60°C to 150°C, more preferably 70°C to 80°C, the time is preferably 1h to 8h, the solid-liquid ratio is preferably 10g / L to 100g / L, and the stirring speed is preferably 300rpm to 600rpm.

[0036] Afterwards, the present invention performs CO 2 Mineralization precipitation step (metal precipitation separation step): After the obtained solution containing the target metal ion complex is purified and impurities are removed, a solution containing CO is introduced. 2 The industrial flue gas is contacted with gas and liquid to achieve flue gas CO 2 Capture, and on this basis, further introduce high-purity and high-pressure CO 2 Formation of high CO 2The reaction system with a high loading amount is subjected to a carbonation precipitation reaction of metal ions, and a metal product is obtained after filtration.

[0037] The present invention has no special limitation on the purification and impurity removal process. The leaching solution can be purified by using a purifying agent and purification process well known to those skilled in the art to obtain a metal complex solution.

[0038] In the present invention, the 2 CO in industrial flue gas 2 The concentration of CO is preferably 4% to 30%. 2 The load is preferably increased to 0.5 or more.

[0039] In the present invention, the high CO 2 The loading amount is preferably greater than or equal to 0.7; in order to improve the efficiency of carbon dioxide mineralization, the present invention 2 Based on absorption and mineralization precipitation, high partial pressure CO 2 To increase the CO 2 The loading amount increases the concentration of carbonate and bicarbonate, further strengthens the mineralization precipitation reaction, and realizes the efficient precipitation separation of metal ions.

[0040] The present invention combines the purified leachate with a mixture containing CO 2 The industrial flue gas is in gas-liquid contact, and the free amine-based leaching agent in the leaching solution reacts with the low partial pressure CO in the flue gas. 2 Absorption reaction occurs, and this process realizes the CO 2 capture; with a secondary amine (R 1 R 2 Take NH) as an example:

[0041] R 1 R 2 NH+CO 2 →R 1 R 2 NH + COO - (2);

[0042] R 1 R 2 NH + COO - +R 1 R 2 NH→R 1 R 2 NCOO - +R 1 R 2 NHH + (3);

[0043]

[0044]

[0045] Absorbing CO 2 The amine-based complexing agent is from low CO 2 Load to high CO 2 The load generates high concentrations of carbamate, carbonate, and bicarbonate, which react with the target metal ions to generate metal carbonates, basic metal carbonates, etc., and the metal products are obtained after filtration. 2 The mineralization process realizes the solid-liquid separation of metal ions:

[0046] [Me(R 1 R 2 NH)n] x+ →Me x+ +nR 1 R 2 NH (6);

[0047]

[0048]

[0049]

[0050] In the present invention, the temperature of the precipitation reaction is preferably 60° C. to 90° C., and the time is preferably 4 h to 8 h.

[0051] In a preferred embodiment of the present invention, by controlling CO 2 The partial pressure of CO and the concentration of the reaction products carbamate, carbonate and bicarbonate are controlled to achieve the step-by-step precipitation separation of multi-component metals and achieve the effect of metal ion separation and purification. In a preferred embodiment of the present invention, by controlling CO 2 The partial pressure of and the concentration of the reaction products carbamate, carbonate and bicarbonate are adjusted to achieve co-precipitation of multi-component metals.

[0052] Finally, the present invention preferably also includes an amino complexing agent regeneration step:

[0053] c) The high CO obtained after filtration 2 The filtrate with a certain amount of loading is sent to the distillation tower for CO 2 Desorption and amine complexing agent regeneration to obtain high-purity CO 2 and low CO 2 The regenerated amine complexing agent is used for metal ion leaching in the next cycle, and the high-purity CO 2 Used for metal precipitation in the next cycle, thus completing the amine complexing agent and high-purity CO 2of recycling.

[0054] In the present invention, CO 2 High CO after mineralization precipitation separation 2 The loaded filtrate contains high concentrations of carbamate, bicarbonate and carbonate, which are sent to the distillation tower for CO2 removal at a certain temperature and pressure. 2 Desorption and regeneration of amine-based complexing agents.

[0055] In the present invention, a reboiler is provided at the bottom of the distillation tower to provide the heat required for the regeneration of the amine-based complexing agent, and a condenser is provided at the top to cool the temperature of the regenerated gas from the distillation tower. The condensed liquid phase is refluxed to the distillation tower body to obtain a low CO 2 Loading amount of amine complexing agent solution (CO 2 The released liquid), the regenerated amine complexing agent enters the next cycle of metal complex leaching and flue gas CO 2 Absorption; gas phase is high purity CO 2 ; wherein the high purity CO 2 The purity is >99%, and it enters the next cycle of mineralization precipitation. The excess CO 2 Used for utilization or underground storage to achieve flue gas CO 2 Emission reduction.

[0056] CO 2 The desorption chemical reaction is as follows:

[0057] R 1 R 2 NH + COO - →R 1 R 2 NH+CO 2 ↑ (10);

[0058]

[0059] In the present invention, the CO 2 During desorption and regeneration of the amino complexing agent, the temperature of the reboiler is preferably 110°C to 130°C, and the pressure is preferably 1 bar to 3 bar; the temperature of the condenser is preferably 35°C to 45°C.

[0060] The present invention provides a metal complex leaching-CO 2 Mineralization precipitation separation - complexing agent and CO 2 The method for extracting and recovering recycled metal resources has the following beneficial effects:

[0061] (1) Amine complexing agents can react with metal ions and CO 2The dual-functional characteristics of absorption reaction can achieve efficient leaching and mineralization precipitation of metals. 2 The reversible reaction of the amine complexing agent can realize the regeneration and recycling of the amine complexing agent, which greatly reduces the consumption of metal leaching agent compared with acid leaching; (2) Utilize CO in industrial waste gas 2 As a mineralizer for metal precipitation, separation and recovery, it can complete the decarbonization of industrial flue gas and significantly reduce the raw material cost of metal separation and precipitation; (3) Amine leaching agent and CO 2 The recycling and reuse of metal resources reduces secondary pollution and its treatment costs during the extraction and recovery of metal resources.

[0062] Compared with the prior art, the metal resource extraction and recovery method provided by the present invention adopts specific process steps to achieve better overall interaction: (1) using an amine complexing agent as a link to selectively leach metals with high efficiency; (2) using an amine complexing agent to react with CO 2 The characteristics of the reaction can achieve the dual benefits of industrial flue gas decarbonization and efficient precipitation and separation of metal ions; (3) using amine complexing agents and CO 2 The reaction is reversible and CO is desorbed by heating at high temperature. 2 The amine-based complexing agent is regenerated by a method to achieve the complexing agent and high-purity CO 2 The recycling of valuable metal waste provides a new method for resource recovery and low-carbon utilization.

[0063] In order to further illustrate the present invention, the following examples are provided for detailed description.

[0064] Example 1

[0065] This embodiment provides a method for extracting and recovering metal resources from waste ternary lithium batteries, wherein the waste ternary lithium batteries are nickel-cobalt-manganese oxide lithium batteries, and the extraction and recovery method comprises the following steps:

[0066] (1) Leaching: The positive electrode powder of the waste ternary lithium battery after reduction roasting is immersed in CO 2 The ethanolamine solution (CO 2 The leaching reaction was carried out in a reaction system formed by (a molar ratio of carbamate, bicarbonate, carbonate and ethanolamine), the reaction temperature was controlled to be 80°C, the reaction time was 6h, the solid-liquid ratio in the leaching reaction was 20g / L, the concentration of ethanolamine solution was 2mol / L, the magnetic stirring speed was 450rpm, and the selective leaching of lithium, cobalt and nickel was achieved. The leaching rates of cobalt, nickel and lithium were 98.2%, 96.6% and 89.4%, and about 98.6% of manganese would remain in the waste residue.

[0067] (2) Precipitation: A 10% CO2 Industrial flue gas, CO in solution 2 The load rises to 0.52 and high-purity CO is continuously introduced. 2 , so that CO 2 The load was increased to 0.8, and then the temperature was controlled at 80°C in a sealed system. The precipitation time was 6 hours to precipitate cobalt and nickel. The precipitation rates of cobalt and nickel were 98.6% and 97.2%, respectively.

[0068] (3) Regeneration of amine complexing agent: After filtration, metal carbonate is obtained. The filtrate is heated to 120°C and sent to a distillation tower for ethanolamine regeneration at a pressure of 2 bar. The condenser temperature is controlled at 40°C to obtain CO with a purity of 99.0%. 2 Gas, and CO 2 The load of ethanolamine solution is 0.2. The energy in the distillation process is provided by the steam of the reboiler, and the heat consumption is 3.9GJ / ton CO 2 .

[0069] Example 2

[0070] This embodiment provides a method for extracting and recovering metal resources from zinc-containing waste slag, wherein the zinc-containing waste slag is zinc slag from the hot-dip galvanizing industry, and the extraction and recovery method comprises the following steps:

[0071] (1) Leaching: The zinc slag powder is immersed in CO 2 The ethanolamine solution (CO 2 The leaching reaction was carried out in a reaction system formed by (a molar ratio of carbamate, bicarbonate, carbonate and ethanolamine) with a load of 97.2%, the reaction temperature was controlled to be 70°C, the reaction time was 6h, the solid-liquid ratio in the leaching reaction was 20g / L, the concentration of ethanolamine solution was 2mol / L, and the magnetic stirring speed was 450rpm, achieving 97.2% selective leaching of zinc ions.

[0072] (2) Precipitation: Filter and separate the waste residue and zinc ion solution, and introduce 10% CO into the separated zinc ion solution. 2 Industrial flue gas, CO in solution 2 The load rises to 0.6, and high-purity CO continues to be introduced 2 , so that CO 2 The loading rate increased to 0.8, generating metal carbonate precipitation. Thereafter, the temperature was controlled at 80°C in the sealed system, and the precipitation time was 6 hours to precipitate zinc ions with a precipitation rate of 99.0%.

[0073] (3) Regeneration of the amine complexing agent: After filtration, zinc carbonate is obtained. The filtrate is heated to 120°C and sent to a distillation tower for ethanolamine regeneration at a pressure of 2 bar. The condenser temperature is controlled at 40°C to obtain CO with a purity of 99.0%.2 Gas, and CO 2 The ethanolamine solution with a loading of 0.2 is used for the next leaching-precipitation-regeneration cycle process.

[0074] Example 3

[0075] This embodiment provides a method for extracting and recovering metal resources from copper-containing waste, wherein the copper-containing waste is copper-containing sludge from a circuit board factory. The method comprises the following steps:

[0076] (1) Leaching: The copper-containing sludge is immersed in a reaction system formed by an aqueous ammonia solution and ammonium bicarbonate for leaching reaction. In terms of molar ratio, the molar ratio of the total amount of carbon to the total amount of nitrogen in the system is 0.2. The reaction temperature is controlled to be 70° C., the reaction time is 6 h, the solid-liquid ratio in the leaching reaction is 20 g / L, the total concentration of the ammonia solution in the reaction system is 2 mol / L, and the magnetic stirring speed is 450 rpm, thereby achieving 96.9% selective leaching of copper ions.

[0077] (2) Precipitation: Filter and separate the waste residue and copper ion solution, and pass 10% CO into the separated copper ion solution. 2 Industrial flue gas, CO in solution 2 The load rises to 0.6, and high-purity CO continues to be introduced 2 , so that CO 2 The loading rate increased to 0.8, generating metal carbonate precipitation. Thereafter, the temperature was controlled at 80°C in the sealed system, and the precipitation time was 6 hours to precipitate copper with a precipitation rate of 97.3%.

[0078] (3)CO 2 Desorption and solvent regeneration: After filtration, basic copper carbonate is obtained. The filtrate is heated to 120°C and sent to the distillation tower for ammonium bicarbonate regeneration under 2 bar pressure. The condenser temperature is controlled at 40°C to obtain CO with a purity of 99.0%. 2 Gas, and CO 2 The load was 0.2 ammonium bicarbonate solution for the next cycle.

[0079] In summary, through the above technical solution, the present invention utilizes the high CO 2 Absorption efficiency and metal leaching selectivity, combined with CO 2 The metal ion precipitation and separation under the action of the metal ion precipitation can achieve the efficient extraction of metals in metal ores and the resource utilization of valuable metal wastes, while achieving low energy consumption and low cost CO 2 Capture and high-value CO 2Utilization; at the same time, chemical reagents are recycled in a closed loop to avoid the generation of wastewater, greatly reducing secondary pollution and its treatment costs; the present invention provides a new technical option for the metal extraction of primary ore and the low-carbon resource utilization of valuable metal waste.

[0080] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for extracting and recovering metal resources, comprising the following steps: a) immersing a raw material containing a valuable metal in an amine-based complexing agent solution with a low CO2 loading amount to perform a leaching reaction, transferring the target metal ions from a solid phase to a liquid phase, and obtaining a solution containing a target metal ion complex; b) purifying and removing impurities from the solution containing the target metal ion complex obtained in step a), and then contacting the solution with industrial flue gas containing CO2 to achieve CO2 capture in the flue gas. On this basis, further introducing high-purity and high-pressure CO2 to form a reaction system with a high CO2 loading amount, and performing a carbonation precipitation reaction of metal ions, and obtaining a metal product after filtering; c) The filtrate with high CO2 loading obtained after filtration in step b) is fed into a distillation tower, CO2 desorption and amine complexing agent regeneration are carried out at a certain temperature and pressure to obtain high-purity CO2 and amine complexing agent regeneration solutions with low CO2 loading, respectively. The regenerated amine complexing agent is used for metal ion leaching in the next cycle of step a), and the high-purity CO2 is used for metal precipitation in the next cycle, thereby completing the recycling of the amine complexing agent and high-purity CO2.

2. The method for extracting and recovering metal resources according to claim 1, characterized in that: The raw material containing valuable metals in step a) is primary ore resources or waste containing valuable metals; wherein the metals include one or more of gold, silver, copper, zinc, lithium, cobalt, nickel, manganese, cadmium and chromium.

3. The method for extracting and recovering metal resources according to claim 1, characterized in that: The amine complexing agent solution in step a) is selected from one or more of an aqueous ammonia solution, an organic amine solution, and an amino acid solution; The low CO2 loading refers to the ratio of the total CO2 molar concentration (including free CO2, carbonate, bicarbonate, and carbamate) in the solution to the molar concentration of the amino complexing agent, and its value is less than or equal to 0.

5. Preferably, the CO2 loading value is 0.2 to 0.

4.

4. The method for extracting and recovering metal resources according to claim 1, characterized in that: The leaching reaction temperature in step a) is 60° C. to 150° C., the time is 1 h to 8 h, the solid-liquid ratio is 10 g / L to 100 g / L, and the stirring speed is 300 rpm to 600 rpm.

5. The method for extracting and recovering metal resources according to claim 1, characterized in that: The concentration of CO2 in the industrial flue gas containing CO2 in step b) is 1% to 95%, preferably 4% to 30%. After the solution and the flue gas CO2 fully react, the CO2 load rises to above 0.5; after the high-pressure and high-purity CO2 is introduced, the CO2 load in the solution is greater than or equal to 0.

7.

6. The method for extracting and recovering metal resources according to claim 1, characterized in that: The temperature of the precipitation reaction in step b) is 20° C. to 100° C., preferably 60° C. to 90° C., and the reaction time is 1 h to 12 h, preferably 4 h to 8 h.

7. The method for extracting and recovering metal resources according to claim 1, characterized in that: In step c), a reboiler is provided at the bottom of the distillation tower to provide the heat required for the regeneration of the amine-based complexing agent, the temperature of the reboiler is 80°C to 150°C, preferably 110°C to 130°C, and the pressure is 1 bar to 5 bar, preferably 1 bar to 3 bar. A condenser is provided at the top to cool the temperature of the regenerated gas of the distillation tower, the condenser temperature is 20°C to 60°C, preferably 35°C to 45°C, the condensed liquid phase is refluxed to the distillation tower body, the condensed gas phase obtains high-purity CO2, and the bottom of the distillation tower obtains an amine-based complexing agent solution with a low CO2 loading.

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