Metal-based isocyanate gold leaching agent and high-temperature catalytic synthesis method thereof

Abstract

The invention discloses a metal-based isocyanate gold leaching agent and a high-temperature catalytic synthesis method thereof. The high-temperature catalytic synthesis method of the metal-based isocyanate gold leaching agent comprises the following steps: grinding and uniformly mixing a proper amount of cyanate and a metal catalyst to obtain a mixture; carrying out high-temperature roasting on the mixture to obtain a roasted product; and the roasted product is naturally cooled and crushed, and the metal-based isocyanate gold leaching agent is obtained. According to the metal-based isocyanate gold leaching agent and the high-temperature catalytic synthesis method thereof, the synthesis raw materials are simple and easy to obtain, the cost is low, the synthesis process is simple and easy to control, the production efficiency is high, the energy consumption is low, and the metal-based isocyanate gold leaching agent has excellent gold leaching performance; the method can replace sodium cyanide to realize efficient gold leaching under the original cyaniding gold leaching process and equipment.

Description

Technical Field

[0001] This invention relates to the fields of hydrometallurgy and mineral processing technology, specifically to a metal-based isocyanate leaching agent and its high-temperature catalytic synthesis method. Background Technology

[0002] Gold possesses dual attributes as both currency and commodity, making it a crucial national strategic resource. Currently, over 90% of the world's gold is obtained through cyanide leaching. However, cyanide is highly toxic, posing a serious threat to ecological security and human health. With increasingly stringent global environmental protection requirements, non-toxic or low-toxicity, environmentally friendly non-cyanide leaching agents have become a research focus for scholars and gold industry technicians both domestically and internationally. Traditional non-cyanide leaching agents (such as thiosulfates, thiourea, thiocyanates, and halogens) have failed to achieve large-scale industrial application due to problems that are difficult to solve in the short term, such as high reagent consumption, poor thermal stability, and high reagent costs. Therefore, industry technicians have begun developing new synthetic non-cyanide leaching agents.

[0003] In recent years, scholars have reported for the first time the synthesis of a gold leaching agent with sodium isocyanate as the main component in the solid state. Their research shows that cyanate synthesized from urea and carbonates can isomerize to form an isocyanate gold leaching agent, and the addition of catalysts such as ferrocyanide, ferrous cyanide, iron powder, and sodium hydroxide during the synthesis process can all improve the gold-dissolving ability of the synthesized agent. When using this gold leaching agent to leach high-sulfur, refractory gold concentrate, under conditions of a stirring speed of 300 rpm, a liquid-to-solid ratio of 3:1, a gold leaching agent dosage of 3.78 kg / t, and a leaching temperature of 31.6℃, the gold leaching rate reached 86.9%. Furthermore, this gold leaching agent can achieve a gold leaching rate of over 98% in different types of gold-containing electronic waste. These results demonstrate that the isocyanate gold leaching agent has excellent gold leaching ability and extremely high value for widespread application. However, ongoing research has revealed that the isocyanate leaching agents synthesized by researchers release a small amount of oxygen and generate free cyanide ions upon dissolving in water. This indicates that isocyanate ions are unstable in aqueous solutions, and that the dissolution of gold by isocyanate leaching agents is essentially driven by cyanide ions. Therefore, addressing the stability of isocyanate ions in aqueous solutions and preventing their conversion into free cyanide ions is crucial for the widespread application and development of isocyanate leaching agents. Summary of the Invention

[0004] To address the technical problem of the instability of isocyanate ions in aqueous solutions of existing isocyanate leaching agents, this invention provides a metal-based isocyanate leaching agent and its high-temperature catalytic synthesis method. The raw materials are simple and readily available, and the cost is low. The synthesis process is simple and easy to control, with high production efficiency and low energy consumption. Furthermore, this metal-based isocyanate leaching agent has excellent leaching performance and can replace sodium cyanide in achieving efficient leaching in existing cyanide leaching processes and equipment.

[0005] This invention provides a high-temperature catalytic synthesis method for metal-based isocyanate gold leaching agents, comprising the following steps: A suitable amount of cyanate and a metal catalyst are ground and mixed evenly to obtain a mixture; The mixture is calcined at high temperature to obtain the calcined product; The roasted product was naturally cooled and crushed to obtain a metal-based isocyanate immersion gold agent.

[0006] In a preferred embodiment of the high-temperature catalytic synthesis method of metal-based isocyanate gold immersion agent provided by the present invention, the mass ratio of the cyanate to the metal catalyst is 1:(0.04~0.4).

[0007] In a preferred embodiment of the high-temperature catalytic synthesis method of metal-based isocyanate immersion gold agent provided by the present invention, the cyanate includes one or more of sodium cyanate, potassium cyanate, and ammonium cyanate.

[0008] In a preferred embodiment of the high-temperature catalytic synthesis method of metal-based isocyanate immersion gold agent provided by the present invention, the cyanate is sodium cyanate or potassium cyanate.

[0009] In a preferred embodiment of the high-temperature catalytic synthesis method of metal-based isocyanate immersion gold agent provided by the present invention, the metal catalyst includes one or more of iron carbide, iron nitride, iron hydroxyl oxide, nickel powder, nickel hydroxyl oxide, cobalt powder, and nickel-cobalt alloy.

[0010] In a preferred embodiment of the high-temperature catalytic synthesis method of metal-based isocyanate immersion gold agent provided by the present invention, the metal catalyst includes one or more of iron carbide, iron nitride, nickel powder, cobalt powder, and nickel-cobalt alloy.

[0011] In a preferred embodiment of the high-temperature catalytic synthesis method of metal-based isocyanate immersion gold agent provided by the present invention, the high-temperature calcination temperature is 600~1000℃ and the calcination time is 30~120min.

[0012] In a preferred embodiment of the high-temperature catalytic synthesis method of metal-based isocyanate immersion gold agent provided by the present invention, the high-temperature calcination temperature is 700~900℃ and the calcination time is 60~100min.

[0013] In a preferred embodiment of the high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent provided by the present invention, the calcined product is naturally cooled, crushed and ground into powder to obtain the metal-based isocyanate immersion gold agent.

[0014] The present invention also provides a metal-based isocyanate leaching agent, which is prepared by a high-temperature catalytic synthesis method of the metal-based isocyanate leaching agent described in any one of the above-mentioned methods.

[0015] Compared with existing technologies, the metal-based isocyanate leaching agent and its high-temperature catalytic synthesis method provided by this invention have the following advantages: The high-temperature catalytic synthesis method of the metal-based isocyanate leaching agent synthesizes the metal-based isocyanate leaching agent by coupling the action of a metal catalyst at high temperature to achieve structural isomerization of cyanate. The raw materials for synthesis are only cyanate and metal catalyst. The raw materials are simple, readily available, and low in cost, and the synthesis process is simple and easy to control. The preparation of the metal-based isocyanate leaching agent adopts a simple one-stage high-temperature calcination, which can significantly reduce energy consumption while ensuring the yield and leaching efficiency of the leaching agent. The raw materials for the synthesis of the leaching agent are added in one go before high-temperature calcination, and the operation process is simple. The metal-based isocyanate leaching agent is non-toxic and environmentally friendly, and can replace cyanide to achieve efficient leaching under the original cyanidation process and equipment conditions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart of the high-temperature catalytic synthesis method of metal-based isocyanate immersion gold agent provided in the embodiments of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of the metal-based isocyanate immersion gold agent provided in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as superior or more advantageous than other embodiments or designs. Rather, the use of the term "exemplary" is intended to present the concept in a specific manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0020] Please see Figure 1 and Figure 2This invention provides a metal-based isocyanate leaching agent, the high-temperature catalytic synthesis method of which may include the following steps: A suitable amount of cyanate and a metal catalyst are ground and mixed evenly to obtain a mixture; The mixture is calcined at high temperature to obtain the calcined product; The roasted product was naturally cooled and crushed to obtain a metal-based isocyanate immersion gold agent.

[0021] Preferably, the mass ratio of the cyanate to the metal catalyst is 1:(0.04~0.4).

[0022] Specifically, the mass ratio of the cyanate to the metal catalyst is 1:(0.04~0.2).

[0023] Preferably, the cyanate includes one or more of sodium cyanate, potassium cyanate, and ammonium cyanate.

[0024] Specifically, the cyanate is sodium cyanate or potassium cyanate.

[0025] Preferably, the metal catalyst includes one or more of iron carbide, iron nitride, iron hydroxyl oxide, nickel powder, nickel hydroxyl oxide, cobalt powder, and nickel-cobalt alloy.

[0026] Specifically, the metal catalyst includes one or more of iron carbide, iron nitride, nickel powder, cobalt powder, and nickel-cobalt alloy.

[0027] Preferably, the high-temperature calcination temperature is 600~1000℃ and the calcination time is 30~120min.

[0028] Specifically, the high-temperature roasting temperature is 700~900℃, and the roasting time is 60~100min.

[0029] Preferably, the roasted product is naturally cooled, crushed and ground into powder to obtain a metal-based isocyanate immersion gold agent.

[0030] Unless otherwise specified, all synthetic raw materials used in this invention are commercially available products well known in the art.

[0031] The present invention does not have special requirements for the grinding and mixing process, as long as the cyanate and the metal catalyst are uniformly mixed; during the high-temperature calcination process, the cyanate undergoes chemical bond breakage and recombination and structural isomerization under the action of the metal catalyst, thereby generating metal-based isocyanate coordination groups that can coordinate with gold; after the high-temperature calcination catalytic synthesis process is completed, the calcined product is preferably naturally cooled to room temperature, and then the calcined product is crushed into fine powder to obtain the metal-based isocyanate gold immersion agent. The present invention does not have special requirements for the crushing process of the calcined product, and crushing processes well known in the art can be used.

[0032] The metal-based isocyanate leaching agent obtained by the above-described high-temperature catalytic synthesis method undergoes high-temperature calcination and the action of a metal catalyst, which causes the chemical bonds in the cyanate to break and the structure to become isomerized, thereby forming a metal-based isocyanate group that can coordinate with gold. The raw materials and processes used are simple and can replace sodium cyanide in existing cyanide leaching equipment and production lines to achieve clean gold leaching.

[0033] Studies have shown that agents capable of gold leaching usually need to meet two conditions: (1) they must contain high-energy-level fully filled σ orbitals and have energy-matching empty π-type orbitals; the N atom in isocyanate (-N=C=O) has lone pairs of electrons, which can donate electrons to form σ coordinate bonds, and its aggregated double bond structure can form feedback π bonds with gold ions. At the same time, small molecule salts have good hydrophilicity and spatial adaptability, which theoretically indicates that isocyanate can achieve coordination gold leaching; the isomerization of cyanate into isocyanate is essentially a rearrangement of the atomic connection sequence inside the anion; firstly, by heating at high temperature The energy provided causes the carbon-nitrogen triple bond (C≡N) in the cyanate ion (OCN-) to break, resulting in electron rearrangement, as shown in Equation 1. Subsequently, under the action of a metal catalyst, the negatively charged nitrogen atom attacks and attaches to the carbon atom, while the chemical bond between the oxygen atom and the carbon atom is adjusted, forming a cumulative double bond structure (N=C=O), as shown in Equation 2. Finally, multiple isocyanate ions combine with metal ions (such as Fe ions) through coordination bonds to form a stable complex ion structure, thereby ensuring its stability in aqueous solution. The structure of this metal-based isocyanate gold leaching agent is as follows: Figure 1 As shown in the figure, the Fe ions can also be metal elements such as Ni or Co in other metal catalysts.

[0034] [:-C≡N]- → [:C=N-] (1)

[0035] [:C=N-] → [O=C=N:]- (2)

[0036] The following detailed description, in conjunction with embodiments, illustrates the metal-based isocyanate immersion gold agent and its high-temperature catalytic synthesis method provided by the present invention. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0037] The raw materials used in the following examples and comparative examples are all from a low-grade oxidized gold mine in Yunnan Province, with a gold grade of 0.93 g / t.

[0038] Unless otherwise specified, the high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent used in the following examples is as follows: The cyanate and the metal catalyst are ground and mixed at a mass ratio of 1:0.08 and then placed in a high-temperature and corrosion-resistant crucible for calcination at a temperature of 750°C for 80 minutes. After calcination, the calcined product is placed in air and allowed to cool naturally to room temperature before being crushed into fine powder to obtain the metal-based isocyanate immersion gold agent.

[0039] Comparative Example 1

[0040] (1) After grinding the cyanate, it was placed in a high-temperature and corrosion-resistant crucible for high-temperature roasting at 750°C for 80 minutes. After roasting, the roasted product was placed in the air to cool naturally to room temperature and then crushed into fine powder to obtain the gold immersion agent.

[0041] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, the gold leaching agent synthesized in (1) (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0042] (3) During the leaching process, a small amount of the leachate was taken at regular intervals to measure the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 1.

[0043] Table 1. Variation of gold leaching rate over time in Comparative Example 1

[0044]

[0045] The results of multiple parallel experiments obtained using the above steps are as follows: with a gold leaching agent concentration of 0.2 wt.%, the gold leaching rate of a low-grade oxidized gold ore in Yunnan is 38.3% after leaching for 24 hours.

[0046] Comparative Example 2

[0047] (1) After grinding cyanate and iron carbide (mass ratio of 1:0.08), the mixture was placed in a high-temperature and corrosion-resistant crucible and calcined at a high temperature of 600℃ for 80 min. After calcination, the calcined product was placed in the air and allowed to cool naturally to room temperature before being crushed into fine powder to obtain metal-based isocyanate gold immersion agent.

[0048] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, a metal-based isocyanate leaching agent (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0049] (3) During the leaching process, a small amount of the leachate was taken at regular intervals to measure the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 2.

[0050] Table 2. Changes in gold leaching rate over time in Comparative Example 2

[0051]

[0052] The results of multiple parallel experiments obtained using the above steps are as follows: with a metal-based isocyanate gold leaching agent concentration of 0.2 wt.%, the gold leaching rate of a low-grade oxidized gold ore in Yunnan was 72.1% after leaching for 24 hours.

[0053] Comparative Example 3

[0054] (1) After grinding cyanate and iron carbide (mass ratio of 1:0.08), the mixture was placed in a high-temperature and corrosion-resistant crucible and calcined at a high temperature of 750℃ for 30 min. After calcination, the calcined product was placed in the air and allowed to cool naturally to room temperature before being crushed into fine powder to obtain metal-based isocyanate gold immersion agent.

[0055] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, a metal-based isocyanate leaching agent (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0056] (3) During the leaching process, a small amount of the leaching solution was taken at regular intervals to test the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 3.

[0057] Table 3. Changes in gold leaching rate over time in Comparative Example 3

[0058]

[0059] The results of multiple parallel experiments obtained using the above steps are as follows: with a metal-based isocyanate leaching agent concentration of 0.2 wt.%, the leaching rate of a low-grade oxidized gold ore in Yunnan was 85.5% after leaching for 24 hours.

[0060] Example 1

[0061] (1) When synthesizing metal-based isocyanate gold leaching agent, iron carbide is selected as the metal catalyst, and other synthesis conditions remain unchanged.

[0062] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, a metal-based isocyanate leaching agent (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0063] (3) During the leaching process, a small amount of the leachate was taken at regular intervals to test the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 4.

[0064] Table 4. Variation of gold leaching rate over time in Example 1

[0065]

[0066] The results of multiple parallel experiments obtained using the above steps are as follows: with a metal-based isocyanate leaching agent concentration of 0.2 wt.%, the leaching rate of a low-grade oxidized gold ore in Yunnan was 99.5% after leaching for 24 hours; compared with Comparative Example 1, under the same synthesis conditions, the leaching performance of the metal-based isocyanate leaching agent synthesized after adding a metal catalyst was significantly improved; compared with Comparative Example 2, the leaching rate of the metal-based isocyanate leaching agent was significantly increased at the preferred roasting temperature; compared with Comparative Example 3, the performance of the metal-based isocyanate leaching agent was significantly enhanced at the preferred roasting time.

[0067] Example 2

[0068] (1) When synthesizing metal-based isocyanate leaching agent, iron nitride is selected as the metal catalyst, and other synthesis process conditions remain unchanged.

[0069] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, a metal-based isocyanate leaching agent (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0070] (3) During the leaching process, a small amount of the leachate was taken at regular intervals to test the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 5.

[0071] Table 5. Changes in gold leaching rate over time in Example 2

[0072]

[0073] The results of multiple parallel experiments obtained using the above steps are as follows: with a metal-based isocyanate gold leaching agent concentration of 0.2 wt.%, the gold leaching rate of a low-grade oxidized gold ore in Yunnan was 99.4% after leaching for 24 hours.

[0074] Example 3

[0075] (1) When synthesizing metal-based isocyanate gold immersion agent, nickel powder is selected as the metal catalyst, and other synthesis process conditions remain unchanged.

[0076] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, a metal-based isocyanate leaching agent (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0077] (3) During the leaching process, a small amount of the leachate was taken at regular intervals to test the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 6.

[0078] Table 6. Variation of gold leaching rate over time in Example 3

[0079]

[0080] The results of multiple parallel experiments obtained using the above steps are as follows: with a metal-based isocyanate gold leaching agent concentration of 0.2 wt.%, the gold leaching rate of a low-grade oxidized gold ore in Yunnan was 98.7% after leaching for 24 hours.

[0081] Example 4

[0082] (1) When synthesizing metal-based isocyanate gold immersion agent, cobalt powder is selected as the metal catalyst, and other synthesis process conditions remain unchanged.

[0083] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, a metal-based isocyanate leaching agent (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0084] (3) During the leaching process, a small amount of the leachate was taken at regular intervals to test the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 7.

[0085] Table 7. Changes in gold leaching rate over time in Example 4

[0086]

[0087] The results of multiple parallel experiments obtained using the above steps are as follows: with a metal-based isocyanate leaching agent concentration of 0.2 wt.%, the leaching rate of a low-grade oxidized gold ore in Yunnan is 99.3% after leaching for 24 hours.

[0088] Example 5

[0089] (1) When synthesizing metal-based isocyanate immersion gold agent, nickel-cobalt alloy is selected as the metal catalyst, and other synthesis process conditions remain unchanged.

[0090] (2) A low-grade oxidized gold ore in Yunnan was finely ground to a -74μm ratio of 85wt.%, and then mixed with water to prepare a slurry (the mass ratio of water to gold ore was 2.5:1). Then, a metal-based isocyanate leaching agent (0.2wt.% of the water mass) was added to the slurry. The initial pH of the slurry was adjusted to 11 using dilute sulfuric acid or sodium hydroxide. Then, the slurry was leached for 24 hours in air at 25℃ and a stirring speed of 250~300r / min.

[0091] (3) During the leaching process, a small amount of the leachate was taken at regular intervals to test the gold concentration in order to calculate the gold leaching rate. The change of gold leaching rate over time is shown in Table 8.

[0092] Table 8. Changes in gold leaching rate over time in Example 5

[0093]

[0094] The results of multiple parallel experiments obtained using the above steps are as follows: with a metal-based isocyanate leaching agent concentration of 0.2 wt.%, the leaching rate of a low-grade oxidized gold ore in Yunnan is 99.2% after leaching for 24 hours.

[0095] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-temperature catalytic synthesis method for a metal-based isocyanate immersion gold agent, characterized in that, Includes the following steps: A suitable amount of cyanate and a metal catalyst are ground and mixed evenly to obtain a mixture; The mixture is calcined at high temperature to obtain the calcined product; The roasted product was naturally cooled and crushed to obtain a metal-based isocyanate immersion gold agent.

2. The high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to claim 1, characterized in that, The mass ratio of the cyanate to the metal catalyst is 1:(0.04~0.4).

3. The high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to claim 1, characterized in that, The cyanate includes one or more of sodium cyanate, potassium cyanate, and ammonium cyanate.

4. The high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to claim 3, characterized in that, The cyanate is sodium cyanate or potassium cyanate.

5. The high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to claim 1, characterized in that, The metal catalyst includes one or more of the following: iron carbide, iron nitride, iron hydroxyl oxide, nickel powder, nickel hydroxyl oxide, cobalt powder, and nickel-cobalt alloy.

6. The high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to claim 5, characterized in that, The metal catalyst includes one or more of iron carbide, iron nitride, nickel powder, cobalt powder, and nickel-cobalt alloy.

7. The high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to claim 1, characterized in that, The high-temperature calcination temperature is 600~1000℃, and the calcination time is 30~120min.

8. The high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to claim 7, characterized in that, The high-temperature calcination temperature is 700~900℃, and the calcination time is 60~100min.

9. The high-temperature catalytic synthesis method of the metal-based isocyanate leaching agent according to claim 1, characterized in that, The roasted product is naturally cooled, crushed and ground into powder to obtain a metal-based isocyanate immersion gold agent.

10. A metal-based isocyanate immersion gold agent, characterized in that, It is prepared by the high-temperature catalytic synthesis method of the metal-based isocyanate immersion gold agent according to any one of claims 1 to 9.

Images