Separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel

Abstract

The present application provides a method for separation-enrichment of gold, iron, and nickel in electronic waste and continuous determination of gold and nickel, belonging to the technical field of metal detection in electronic waste. The method comprises the following steps: electronic waste containing iron, nickel, and gold is mixed with a reagent, water is added for dissolution, and solid-liquid separation is performed to obtain a gold-containing solid and a filtrate; a diluent of a nickel chelate collector is added to the filtrate for extraction, the inorganic phase solution is separated, a reverse collector is added to the organic phase solution for back extraction, and the nickel content is detected; the pH value of the inorganic phase solution is adjusted to a predetermined range to achieve precipitation and purification of the iron; the gold-containing solid is dried, and the gold content is detected by fire assay. The present application achieves separation-enrichment of gold, iron, and nickel through front-end separation of iron and nickel, efficient capture of nickel, precipitation and purification of iron, and precise enrichment of gold, while taking into account the recycling of resources, ensuring the precise testing of subsequent gold content, and achieving the accuracy of gold element content testing in electronic waste.

Description

Technical Field

[0001] The invention relates to the technical field of detection of gold, iron and nickel in electronic waste, and in particular to a method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel. Background Art

[0002] E-waste, considered an "urban mineral," contains a wealth of precious metals, particularly gold, which can reach concentrations dozens of times higher than those found in natural deposits. This offers enormous potential for recycling. For example, every ton of used mobile phones can yield approximately 350 grams of gold, far exceeding the average gold grade (typically less than 5 grams per ton). E-waste recycling not only creates significant economic benefits but also reduces energy consumption by over 70% compared to ore smelting.

[0003] The occurrence of gold in e-waste differs significantly from that of natural minerals, and its complexity poses a challenge to traditional detection techniques. For example, printed circuit boards (PCBs) exhibit a layered, composite structure where precious metals are often embedded within an iron-nickel alloy matrix as micron-sized single-element particles or multi-element alloy aggregates. The chemical bonding of these synthetic materials differs fundamentally from the crystal structure of natural minerals, making it difficult to accurately analyze the concentrations of individual metals in e-waste using traditional methods, such as mineral image analysis. Therefore, other detection methods must be used in conjunction with these methods.

[0004] While fire assay is a widely used method for measuring gold content, it's primarily applied to natural minerals and has limitations for detecting gold in non-natural mineral resources like electronic waste. For example, the iron and nickel content in electronic waste is excessively high, representing 5 to 8 orders of magnitude of the mass of gold. High iron content reacts readily with sulfur sources in the sample to form ferrous sulfide. During the test, ferrous sulfide adheres to the surface of the lead beads, preventing them from agglomerating and causing lead entanglement. This prevents the complete capture of gold, ultimately preventing accurate determination of the sample's gold content. High nickel content, however, can enrich gold, and during the ash blowing process, gold enters the ash dish as the nickel oxidizes, resulting in a low gold result.

[0005] In view of this, it is necessary to design an improved separation-enrichment method for gold, iron and nickel in electronic waste and a continuous determination method for gold and nickel to solve the above problems. Summary of the Invention

[0006] In view of the technical problems existing in the background technology, the present application provides a method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel, aiming to solve the technical problem that traditional content detection methods are difficult to accurately analyze the content of each metal in electronic waste.

[0007] The present application provides a method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel, comprising the following steps:

[0008] S1. The electronic waste containing iron, nickel, and gold is mixed with a reagent, dissolved in water, and separated into a gold-containing solid and a filtrate by solid-liquid separation;

[0009] S2. Add a dilution of a nickel chelate collector to the filtrate obtained in step S1 for extraction, separate the inorganic phase solution, add a reverse collector to the organic phase solution for back extraction, and detect the nickel content; the structural formula of the nickel chelate collector is:

[0010] ;

[0011] S3. adjusting the pH value of the inorganic phase solution obtained in step S2 to a predetermined range to achieve precipitation and purification of iron;

[0012] S4. Drying the gold-containing solid obtained in step S1 and detecting the gold content by fire assay.

[0013] As a further improvement of the present application, in step S1, the agent consists of sodium persulfate and sodium glycinate.

[0014] As a further improvement of the present application, the mass ratio of sodium persulfate to sodium glycinate is 1:(1~1.5).

[0015] As a further improvement of the present application, the mass ratio of the agent to the electronic waste is (1~50):1.

[0016] As a further improvement of the present application, in step S2, the diluted solution of the nickel chelate collector is prepared by mixing the nickel chelate collector and sulfonated kerosene in a volume ratio of 1:(5-10).

[0017] As a further improvement of the present application, the volume ratio of the diluted nickel chelate collector to the filtrate is 1:(1~9).

[0018] As a further improvement of the present application, in step S2, the reverse collector is a glutamic acid solution with a concentration of 30-50 g / L.

[0019] As a further improvement of the present application, the volume ratio of the reverse collector to the diluted solution of the nickel chelate collector is (10-50):1.

[0020] As a further improvement of the present application, in step S1, the pH value of the filtrate is 8-9.

[0021] As a further improvement of the present application, in step S3, the pH value of the inorganic phase solution is 12-14.

[0022] The beneficial effects of this application are:

[0023] The present application provides a method for separation-enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel, comprising the steps of mixing electronic waste containing iron, nickel and gold with a reagent, adding water for dissolution, and performing solid-liquid separation to obtain a gold-containing solid and a filtrate; adding a diluent of a nickel chelate collector to the filtrate for extraction, separating the inorganic phase solution, adding a reverse collector to the organic phase solution for back extraction, and detecting the nickel content; adjusting the pH value of the inorganic phase solution to a predetermined range to achieve precipitation and purification of the iron; drying the gold-containing solid, and detecting the gold content by fire assay. The present application achieves separation-enrichment of gold, iron and nickel through a four-stage process of front-end separation of iron and nickel, efficient capture of nickel, precipitation and purification of iron, and precise enrichment of gold, while taking into account the recycling of resources and ensuring the precise testing of the subsequent gold content, ultimately achieving the accuracy of the gold element content test in electronic waste.

[0024] This application describes the design and synthesis of a nickel chelate collector for the efficient nickel capture step, enabling the selective extraction and separation of nickel and iron from aqueous solutions. This chelate collector, based on a phenylalanine molecular backbone, consists of two sulfur atoms (S) and an imino group (-NH) linked by a carbon atom. Its structural formula is S=C(-SH)-NH-R, where R is an aromatic ring derived from phenylalanine. This unique aromatic ring structure ensures the extractant's hydrophobicity. Furthermore, the sulfur atom in the molecular structure has a low electronegativity (S: 2.58), and the thiocarbonyl group (C=S) is less polar than the carbonyl group (C=O), resulting in weak hydrogen bonding, which minimizes excessive intermolecular self-association. These weak intermolecular forces facilitate the release of lone pairs of electrons from the sulfur and amino groups, or from the carboxyl group, allowing it to preferentially coordinate with metal ions rather than other molecules. This characteristic is crucial in the targeted chelation of metal ions, improving the kinetics and recovery of metal extraction processes. The synergistic effect of the carboxyl group and the "semi-thiourea" structural fragment can reduce the nonspecific binding with other impurity ions, avoid the interference of impurities, and thus improve the selectivity of chelation.

[0025] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0027] Figure 1 A diagram showing the mechanism of action of the nickel chelate collector provided in this application;

[0028] Figure 2 This is a synthetic route diagram of the nickel chelate collector provided in Example 7 of the present application;

[0029] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the nickel chelate collector provided in Example 7 of the present application. DETAILED DESCRIPTION

[0030] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0032] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] The complex occurrence of gold in e-waste makes it difficult to accurately determine its content using traditional detection techniques. Fire assaying, however, can be inaccurate due to high iron and nickel content, which can lead to lead contamination and nickel-enriched gold.

[0034] In order to solve the technical problem that it is difficult to accurately determine gold in electronic waste, the present application provides a method for the separation and enrichment of gold, iron and nickel in electronic waste and the continuous determination of gold and nickel. The method realizes the separation and enrichment of gold, iron and nickel through a four-stage process of front-end separation of iron and nickel, efficient capture of nickel, precipitation purification of iron, and precise enrichment of gold, while taking into account the recycling of resources and ensuring the subsequent accurate testing of gold content, thereby ultimately achieving the accuracy of the gold element content test in electronic waste.

[0035] The present invention provides a method for separating and enriching gold, iron, and nickel in electronic waste and continuously determining gold and nickel, comprising the following steps:

[0036] S1. The electronic waste containing iron, nickel, and gold is mixed with a reagent, dissolved in water, and separated into a gold-containing solid and a filtrate by solid-liquid separation;

[0037] S2. A nickel chelate collector dilution was added to the filtrate obtained in step S1 for extraction, the inorganic phase solution was separated, a reverse collector was added to the organic phase solution for back extraction, and the nickel content was detected; the structural formula of the nickel chelate collector is:

[0038] ;

[0039] S3. Adjusting the pH value of the inorganic phase solution obtained in step S2 to a predetermined range to achieve iron precipitation purification;

[0040] S4. Drying the gold-containing solid obtained in step S1 and detecting the gold content by fire assay.

[0041] In the technical solution of the embodiment of the present application, the iron and nickel in the electronic waste are dissolved by adding a reagent and water, and gold is initially separated from iron and nickel; the reagent adjusts the pH value of the mixed solution to alkaline. Under alkaline conditions, nickel ions form a stable complex with a specific nickel chelate collector to achieve nickel extraction. Thereafter, a reverse collector is added to destroy the complexation between nickel and the chelate collector, so that nickel re-enters the aqueous phase, facilitating the detection of nickel content. The structural formula of the chelate collector is S=C(-SH)-NH-R, where R is an aromatic ring group derived from phenylalanine; the inorganic phase solution adjusts the pH value to a range where iron ions can form iron hydroxide precipitation, so that iron is separated from the solution in the form of a precipitate, which is convenient for resource recovery; the gold-containing solid obtained by the preliminary separation is dried to remove moisture, and then the gold content is determined by fire assay. Since the aforementioned steps have effectively removed the interference of iron and nickel, the accuracy of the fire assay is significantly improved. Specifically, the gold detection method refers to the "GB / T 7739" standard fire assay.

[0042] This application avoids the lead hanging phenomenon caused by high iron content and the low gold content caused by high nickel content enrichment of gold by separating and enriching iron and nickel, improves the accuracy of gold content determination, and helps to improve resource recovery efficiency by accurately determining the content of precious metals in electronic waste, realize high-value utilization of electronic waste, and reduce energy consumption and environmental pollution.

[0043] Furthermore, in some embodiments, in step S1, the agent consists of sodium persulfate and sodium glycinate.

[0044] In the technical solution of the embodiment of the present application, sodium persulfate provides strong oxidizing power, destroying the surface passivation layer of metals in electronic waste and promoting metal dissolution; sodium glycinate stabilizes the dissolved metal ions such as iron and nickel in the solution through complexation, preventing precipitation, and assists the dissolution process through reduction. The two work synergistically to efficiently and selectively leach impurity metals such as iron and nickel from electronic waste into the filtrate, while gold is retained in the solid residue due to its chemical stability, thus achieving preliminary solid-liquid separation and gold enrichment. At the same time, sodium glycinate has a strong alkalinity, which helps to adjust the pH value of the mixed solution.

[0045] Furthermore, in some embodiments, the mass ratio of sodium persulfate to sodium glycinate is 1:(1-1.5), and the mass ratio of the reagent to electronic waste is (1-50):1.

[0046] In the technical solution of the embodiment of the present application, by controlling the ratio and dosage of sodium persulfate and sodium glycinate, the leaching effect of target metals such as iron and nickel can be optimized. Specifically, in the mixture of electronic waste, reagents and water, the concentration of electronic waste is 1-10g / L.

[0047] Furthermore, in some embodiments, in step S2, the diluted solution of the nickel chelate collector is prepared by mixing the nickel chelate collector and sulfonated kerosene in a volume ratio of 1:(5-10).

[0048] In the technical solution of the embodiment of the present application, Figure 1 As shown, nickel chelate collectors are organic reagents with a specific structure that form stable chelates with nickel ions. This chelate has high solubility in sulfonated kerosene but low solubility in aqueous phases. Through this selective chelation and solubility, nickel chelate collectors can effectively extract nickel ions from aqueous phases. An optimal ratio of nickel chelate collector to sulfonated kerosene helps minimize the viscosity and density of the organic phase while ensuring effective extraction, facilitating subsequent separation operations.

[0049] Furthermore, in some embodiments, the volume ratio of the nickel chelate collector dilution to the filtrate is 1:(1-9).

[0050] In the technical solution of the embodiment of the present application, the appropriate volume ratio helps to control the mass transfer rate between the organic phase and the aqueous phase, ensuring that nickel ions can quickly and efficiently enter the organic phase during the extraction process, which helps the nickel ions to fully contact the organic phase, thereby improving the extraction efficiency of nickel.

[0051] Furthermore, in some embodiments, in step S2, the reverse collector is a glutamic acid solution with a concentration of 30-50 g / L.

[0052] In the technical solution of the embodiment of the present application, the organic phase containing the nickel chelate is contacted with the reverse collector glutamate solution. Glutamic acid can compete with the nickel chelate collector to bind nickel ions, forming a water-soluble nickel glutamate complex, thereby allowing the nickel ions to re-enter the aqueous phase, facilitating the detection of nickel concentration.

[0053] Furthermore, in some embodiments, the volume ratio of the reverse collector to the diluted solution of the nickel chelate collector is (10-50):1.

[0054] In the technical solution of the embodiments of the present application, a higher volume of glutamate solution can provide sufficient glutamate molecules to ensure that nickel ions can be effectively stripped from the organic phase. If the volume of the glutamate solution is too small, it may not provide enough glutamate molecules to react with all nickel chelates, resulting in incomplete stripping, affecting the nickel recovery rate and the accuracy of the test results.

[0055] Furthermore, in some embodiments, in step S1, the pH value of the filtrate is 8-9.

[0056] In the technical solution of the embodiment of the present application, alkaline conditions facilitate the nickel chelate collector to function, improving the chelation efficiency of nickel ions. In addition, at a pH of 8-9, the iron ions chelate with the glycine anion, resulting in a solution state, which avoids interference from iron precipitation.

[0057] Furthermore, in some embodiments, in step S3, the pH value of the inorganic phase solution is 12-14.

[0058] In the technical solution of the embodiment of the present application, iron ions are more likely to form hydroxide precipitates under specific pH conditions, which helps to purify iron.

[0059] Some specific examples are listed below. It should be noted that the examples described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used without manufacturer's indication are all commercially available conventional products.

[0060] Example 1

[0061] This embodiment provides a method for treating a nickel-containing solution with a nickel chelate collector, comprising the following steps:

[0062] Add 1L of standard [Ni(NH3)6] with a concentration of 10mg / L and a pH of 9 2+ 10 ml of a diluted nickel chelate collector is added to the alkaline solution, wherein the structural formula of the nickel chelate collector is:

[0063] The nickel chelate collector dilution solution was prepared by mixing the nickel chelate collector with sulfonated kerosene in a volume ratio of 1:9. The mixture was stirred for 30 minutes, and the organic phase solution was collected. 50 ml of a 40 g / L glutamic acid solution was added to the collected organic phase solution, and the mixture was stirred for 30 minutes. The inorganic aqueous phase solution was collected, and the nickel concentration was measured using ICP-OES (inductively coupled plasma optical emission spectrometry). The detection error of ICP-OES was ±2%. The collection capacity of the nickel chelate collector was determined according to the following formula:

[0064] Nickel content (%) = C1 × V1 / (C0 × V0) × 100% (1)

[0065] Wherein, C1 is the nickel concentration in glutamic acid solution detected by ICP-OES;

[0066] V1 is the volume of glutamate solution;

[0067] C0 is the standard [Ni(NH3)6] used in the experiment 2+ The concentration of the alkaline solution;

[0068] V0 is the standard [Ni(NH3)6] used in the experiment 2+ The volume of the alkaline solution.

[0069] Example 2 and Comparative Examples 1-7

[0070] Example 2 and Comparative Examples 1-7 respectively provide a method for treating a nickel-containing solution with a nickel chelate collector. Compared with Example 1, the only difference is that the standard [Ni(NH3)6] 2+ The pH value of the alkaline solution is different. The test results are shown in Table 1.

[0071] Table 1 Capture capacity

[0072]

[0073] — represents the value below the detection limit of ICP-OES.

[0074] Table 1 shows that the nickel chelate collector provided in Example 1 exhibits a significant nickel capture capacity influenced by pH under alkaline conditions, achieving extraction efficiency exceeding 97% within a specific pH range (8-9). Under acidic or neutral conditions (pH ≤ 7), the nickel chelate collector decomposes, affecting nickel capture in solution. Alkaline conditions (8-9) ensure the stability of the nickel chelate collector. When the pH exceeds 9, the dissociated sulfhydryl groups (-S-) of the nickel chelate collector form sulfhydryl bonds (-SS-), which affect the collector's chelation efficiency. This optimal pH range provides a prerequisite for the leaching, extraction, and recovery of nickel from electronic waste.

[0075] Example 3

[0076] This embodiment provides a method for separating and enriching gold, iron, and nickel in electronic waste and continuously determining gold and nickel, comprising the following steps:

[0077] S1. Mix 5g of electronic waste containing iron, nickel, and gold (discarded USB interface material, with a gold content standard of 3410g / t, determined by the manufacturer's process consumables report) with 20g of sodium persulfate and 20g of sodium glycinate. Add 1L of deionized water and dissolve at room temperature for 8h. The iron and nickel in the electronic waste, present as elements or alloys, are oxidized by sodium persulfate and then chelated with glycine anions in an alkaline environment. The chelate dissolves in the liquid phase, transferring the solid form to the liquid phase. After solid-liquid separation, a gold-containing solid and a filtrate are obtained. The nickel content in the electronic waste is determined according to the following formula:

[0078] Nickel content in electronic waste (%) = C × V / m × 100% (2)

[0079] Wherein, C is the concentration of nickel in the filtrate;

[0080] V is the volume of the filtrate;

[0081] m is the mass of electronic waste used in the experiment;

[0082] S2. 1 L of a nickel chelate collector dilution solution was added to the filtrate and stirred for 30 min for extraction. The nickel chelate collector dilution solution was prepared by mixing the nickel chelate collector with sulfonated kerosene in a volume ratio of 1:9. The inorganic phase solution was separated and the nickel concentration in the inorganic aqueous phase after extraction was detected. 10 L of a 40 g / L glutamic acid solution was added to the organic phase solution and stirred for 30 min for back extraction. The inorganic aqueous phase solution was collected and the nickel concentration in the inorganic aqueous phase after back extraction was detected. The structural formula of the nickel chelate collector is:

[0083] ;

[0084] S3. Sodium hydroxide was added to adjust the pH of the inorganic phase solution obtained in step S2 to 12 to generate an iron hydroxide precipitate to achieve the purpose of purifying the iron in the solution system;

[0085] S4. Drying the gold-containing solid obtained in step S1 and detecting the gold content by fire assay.

[0086] Example 4

[0087] This example provides a method for separating and enriching gold, iron, and nickel in electronic waste and continuously determining the gold and nickel contents. Compared to Example 3, the only difference is that the electronic waste is 5 g of material from the connection points of discarded printed circuit boards containing iron, nickel, and gold, and the gold content standard value is 1500 g / t (the value is determined by the manufacturer's process consumables reporting).

[0088] Example 5

[0089] This embodiment provides a method for separation and enrichment of gold, iron, and nickel in electronic waste and continuous determination of gold and nickel. Compared with Example 3, the only difference is that the mass ratio of sodium persulfate to sodium glycinate is 1:1.5.

[0090] Example 6

[0091] This embodiment provides a method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel. Compared with Example 3, the only difference is that the pH value of the inorganic phase solution is adjusted to 14.

[0092] Comparative Example 8

[0093] Comparative Example 8 provides a method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel. Compared with Example 3, the only difference is that 1.00 mg of gold is additionally added in step S1.

[0094] Comparative Example 9

[0095] Comparative Example 9 provides a method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel. Compared with Example 4, the only difference is that 1.00 mg of gold is additionally added in step S1.

[0096] Comparative Example 10

[0097] Comparative Example 10 provides a method for separation and enrichment of gold, iron, and nickel in electronic waste and continuous determination of gold and nickel. Compared with Example 3, the only difference is that the electronic waste is directly tested by fire assay, and the test and analysis method refers to "GB / T 7739".

[0098] Comparative Example 11

[0099] Comparative Example 11 provides a method for separation and enrichment of gold, iron, and nickel in electronic waste and continuous determination of gold and nickel. Compared with Example 4, the only difference is that the electronic waste is directly tested by fire assay, and the test and analysis method refers to "GB / T 7739".

[0100] The test results are shown in Tables 2 and 3.

[0101]

[0102] As shown in Table 2, Examples 3-5 achieved nickel leaching in step S1 and highly efficient nickel capture (extraction rate >99%) in step S2. Furthermore, nickel recovery was achieved through the reverse extraction process, with a stripping rate >90%. This not only ensured accurate subsequent gold measurement but also enabled the recycling of nickel resources.

[0103] Table 3 Error between standard value and experimental value of gold

[0104]

[0105] in, .

[0106] As can be seen from Table 3, the traditional method has a large test error. The method provided in this application has a high accuracy in different types of standard electronic waste samples with different content ratios, with an error range of less than 7%, which meets the requirements of existing tests and their standards.

[0107] Example 7

[0108] This embodiment provides a method for preparing a nickel chelate collector, and the synthesis scheme is as follows: Figure 2 As shown, the specific steps include:

[0109] Dissolve 1 mol of phenylalanine and 1.5 mol of sodium hydroxide in 50 ml of water, stir and dissolve for 30 minutes, return to room temperature, add 1.2 mol of carbon disulfide, heat to 50°C, and reflux for 2 hours. After the reaction is completed, remove excess carbon disulfide and water by rotary evaporation at 70°C to prepare an orange-yellow oily nickel chelate collector with a yield of 81%. Its H NMR spectrum is shown below. Figure 3 (a) shows the full H NMR spectrum, and (b) a zoomed-in view of the H NMR spectrum in the chemical shift range of 4.70–5.00. Specific NMR test results are as follows: 300 MHz, deuterated with D₂O, δ13.00–14.00 (1H, derived from NH₂), δ9.00–10.00 (5H, derived from the benzene ring), and δ4.80–4.82 (2H, derived from the methylene group). NMR characterization confirmed the synthesis of the target product, and the molecular structure of the nickel chelate collector was sodium phenylalanine dithiocarbamate.

[0110] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and within the scope of the technical solution of the present application, embodiments having substantially the same structure as the technical concept and exerting the same effects are all included in the technical scope of the present application. In addition, within the scope of the subject matter of the present application, various modifications that can be conceived by those skilled in the art to the embodiments, and other methods constructed by combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel, characterized in that: The following steps are involved: S1. The electronic waste containing iron, nickel, and gold is mixed with a reagent, dissolved in water, and separated into a gold-containing solid and a filtrate by solid-liquid separation; S2. Add a dilution of a nickel chelate collector to the filtrate obtained in step S1 for extraction, separate the inorganic phase solution, add a reverse collector to the organic phase solution for back extraction, and detect the nickel content; the structural formula of the nickel chelate collector is: ； S3. adjusting the pH value of the inorganic phase solution obtained in step S2 to a predetermined range to achieve precipitation and purification of iron; S4. Drying the gold-containing solid obtained in step S1 and detecting the gold content by fire assay.

2. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 1, characterized in that: In step S1, the reagent consists of sodium persulfate and sodium glycinate.

3. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 2, characterized in that: The mass ratio of the sodium persulfate to sodium glycinate is 1:(1-1.5).

4. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 2, characterized in that: The mass ratio of the agent to the electronic waste is (1-50):

1.

5. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 1, characterized in that: In step S2, the diluted solution of the nickel chelate collector is prepared by mixing the nickel chelate collector and sulfonated kerosene in a volume ratio of 1:(5-10).

6. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 5, characterized in that: The volume ratio of the diluted nickel chelate collector to the filtrate is 1:(1-9).

7. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 1, characterized in that: In step S2, the reverse collector is a glutamic acid solution with a concentration of 30-50 g / L.

8. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 7, characterized in that: The volume ratio of the reverse collector to the diluted solution of the nickel chelate collector is (10-50):

1.

9. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 1, characterized in that: In step S1, the pH value of the filtrate is 8-9.

10. The method for separation and enrichment of gold, iron and nickel in electronic waste and continuous determination of gold and nickel according to claim 1, characterized in that: In step S3, the pH value of the inorganic phase solution is 12-14.

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