Preparation method of high-sphericity gold powder

Abstract

The invention provides a preparation method of high-sphericity gold powder, and relates to the technical field of nano material preparation. The preparation method comprises the following steps: sequentially adding a multi-ligand stabilizer solution and an acid solution into a chloroauric acid solution, and adjusting the pH value of a reaction system to 4.0-5.0 to obtain a solution A; then, quickly adding a dispersing agent solution into the solution A for first-stage mixing, and then, quickly adding a reducing agent solution for second-stage mixing; and then, a morphology optimizing agent solution is dropwise added into a reaction system, precipitates are collected after full reaction, and the high-sphericity-degree gold powder is obtained. According to the method, a multi-ligand stabilizer is added into a chloroauric acid solution, and accurate control over the morphology of the gold powder is achieved through competitive adsorption between ligands. On the basis, an acid solution is added into a chloroauric acid solution, morphology control over the gold powder is further consolidated, the pH value of the solution adjusted through the acid solution is acidic, the reduction rate is further decreased, and the gold powder is better in dispersity and more uniform in size.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nanomaterial preparation, and particularly relates to a preparation method of high-sphericity gold powder. BACKGROUND

[0002] Gold powder has excellent conductivity, thermal conductivity, chemical stability, corrosion resistance, ductility and other properties, making it irreplaceable in industrial applications. Gold powder can be applied to additive manufacturing, high-end semiconductor packaging, thick film hybrid integrated circuits, microwave radio frequency components, chemical catalysis, biological medicine, aerospace and other technical fields.

[0003] In recent years, additive manufacturing technology has gradually penetrated into the fields of aerospace, medicine, automobiles and other high-end manufacturing, which has led to a rapid growth trend in the application of gold powder in additive manufacturing. With the development of additive manufacturing technology, it is increasingly important to ensure the stability of the printing process and the performance of the finished product by strictly controlling the sphericity, particle size distribution and fluidity of gold powder.

[0004] In the prior art, patent application CN114833334A provides a method for continuously preparing micron-sized spherical gold powder. The spherical gold powder obtained by this method has a wide particle size distribution and poor sphericity. Moreover, this method uses multiple reactors for long-time high-temperature reaction, which increases the difficulty of gold powder recovery.

[0005] Therefore, it is necessary to develop a preparation method of high-sphericity gold powder to solve the above problems. SUMMARY

[0006] In view of the defects of the above prior art, the purpose of the present application is to provide a preparation method of high-sphericity gold powder to simply and efficiently prepare gold powder with high sphericity, good dispersibility and uniform size.

[0007] To achieve the above purpose, the present application provides a preparation method of high-sphericity gold powder, comprising the following steps: S1, under stirring, a multi-ligand stabilizer solution, an acid solution are sequentially added to a chloroauric acid solution, the pH of the reaction system is adjusted to 4.0-5.0 to obtain solution A; the multi-ligand stabilizer solution comprises at least two of ammonia, ethylenediamine, polyethyleneimine, triethylamine, sodium thiosulfate, sodium citrate, sodium iodide, methylamine, n-propylamine and 4-dimethylaminopyridine; S2, under stirring, a dispersant solution is quickly added to the solution A for first-stage mixing, then a reducing agent solution is quickly added for second-stage mixing; thereafter, a morphology optimization agent solution is added dropwise to the reaction system, and the precipitate is collected after sufficient reaction; S3, washing, drying and dispersing the precipitate, to obtain the high-sphericity gold powder.

[0008] Further, in step S1, the molar ratio of chlorauric acid in the chlorauric acid solution to the ligand stabilizer in the multi-ligand stabilizer solution is 1:(1-10).

[0009] Further, the acid solution is one or more of hydrochloric acid, citric acid, oxalic acid and acetic acid.

[0010] Further, in step S2, the dispersant is one or more of sodium dodecyl sulfate, polyvinylpyrrolidone, methyl cellulose, polyurethane, glyceryl stearate, stearic acid, oleic acid, polyvinyl alcohol and undecyl mercaptan.

[0011] Further, the first-stage mixing time is 0.5-5 min.

[0012] Further, the reducing agent is one or more of sodium borohydride, hydrazine hydrate, hydrazine hydrochloride, sodium citrate, sodium sulfite, formaldehyde, ascorbic acid, sodium bisulfite, triethanolamine and hydrazine carbonate.

[0013] Further, the second-stage mixing time is 0.5-10 min.

[0014] Further, the morphology optimization agent is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate, the dropping speed of the morphology optimization agent is 10-100 mL / min, and the sufficient reaction time after dropping is completed is 5-20 min.

[0015] Further, the washing process comprises: first washing the precipitate with deionized water until the conductivity is <15 μS / cm, removing the supernatant to obtain a first precipitate, and the water content of the first precipitate is ≤10%; then washing the first precipitate with ethanol, removing the supernatant to obtain a second precipitate.

[0016] Further, in step S3, the drying method is air blowing drying, and the dispersing process is polishing and dispersing.

[0017] The present application has the following beneficial effects: 1. The application provides a preparation method of high-sphericity gold powder, which realizes accurate control of gold powder morphology by adding multiple ligand stabilizers to a chloroauric acid solution through competitive adsorption between ligands. The combination of multiple ligands can slow down the reduction rate, which is conducive to the generation of a large number of small-sized and monodisperse crystal nuclei, thereby realizing control of the size and dispersity of gold powder. On this basis, an acidic solution is added to the chloroauric acid solution to further consolidate the control of the morphology of gold powder. The pH of the solution adjusted by the acidic solution is acidic, which further slows down the reduction rate, so that the dispersity of gold powder is better and the size is more uniform. Based on the synergistic treatment of the chloroauric acid solution by the multiple ligand stabilizers and the acidic solution, the gold powder prepared by the application has the characteristics of high sphericity, good dispersity and uniform size.

[0018] 2. The application provides a preparation method of high-sphericity gold powder, which is based on the synergistic treatment of the chloroauric acid solution by the multiple ligand stabilizers and the acidic solution, and further increases a morphology optimization agent solution during the reaction process. On the one hand, it is conducive to the generation of a large number of small and uniform crystal nuclei, so that the finally obtained gold powder has the characteristics of uniform size and good monodispersity. On the other hand, it reacts with the dispersant in the chloroauric acid solution, effectively reduces the content of the dispersant on the surface of gold powder, and further significantly reduces the viscosity of the slurry, effectively improves the rheological properties of the slurry, and is suitable for the field of 3D printing.

[0019] 3. The application provides a preparation method of high-sphericity gold powder, which is simple and stable, easy to realize repeatedly, and can realize controllable preparation of gold powder. The process equipment used is all commercially available conventional equipment, which is easy to operate and purchase, and can meet the needs of industrialized scale production. The gold powder prepared based on the method provided by the application has a particle size of 0.3-1 μm, high sphericity, good dispersity and uniform size. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 SEM image of gold powder prepared in Example 1.

[0021] Figure 2 SEM image of gold powder prepared in Example 2.

[0022] Figure 3 SEM image of gold powder prepared in Example 3.

[0023] Figure 4 SEM image of gold powder prepared in Comparative Example 1.

[0024] Figure 5 SEM image of gold powder prepared in Comparative Example 2.

[0025] Figure 6 SEM image of gold powder prepared in Comparative Example 3.

[0026] Figure 7 SEM image of gold powder prepared for Comparative Example 4. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0028] Here, it also needs to be noted that, in order to avoid the present application being obscured by unnecessary details, only structures and / or processing steps closely related to the solutions of the present application are shown in the accompanying drawings, and other details not closely related to the present application are omitted.

[0029] In addition, it also needs to be noted that the term "comprise", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device.

[0030] In the prior art, the preparation method of gold powder has problems such as complex reaction process, low sphericity of gold powder and poor dispersibility.

[0031] The present application provides a preparation method of high-sphericity gold powder, comprising the following steps: S1, under stirring, a multi-ligand stabilizer solution and an acid solution are sequentially added to a chloroauric acid solution, the pH of the reaction system is adjusted to 4.0-5.0 to obtain solution A; wherein the multi-ligand stabilizer solution comprises at least two of ammonia, ethylenediamine, polyethyleneimine, triethylamine, sodium thiosulfate, sodium citrate, sodium iodide, methylamine, n-propylamine and 4-dimethylaminopyridine.

[0032] The acid solution is one or more of hydrochloric acid, citric acid, oxalic acid and acetic acid.

[0033] The molar ratio of chloroauric acid in the chloroauric acid solution to the ligand stabilizer in the multi-ligand stabilizer solution is 1:(1-10). When the molar ratio of chloroauric acid to ligand stabilizer is in the range of 1:1-1:10, the chloroauric acid is sufficient to complex with the multi-ligand stabilizer, the reduction process is controllable, the sphericity of the gold powder is high, the dispersibility is good, and the size of the gold powder gradually increases with the increase of the multi-ligand stabilizer. When the molar ratio of chloroauric acid to ligand stabilizer is greater than 1:1, due to the excessive small amount of ligand stabilizer, the precursor complex is non-uniform and unstable, which leads to wide particle size distribution of the gold powder, serious agglomeration and irregular morphology in the reduction process. When the molar ratio of chloroauric acid to ligand stabilizer is less than 1:10, the excessive ligand stabilizer leads to too stable coordination environment, which reduces the reduction reaction rate, makes the nucleation and growth process of gold atoms unbalanced, and easily produces some oversized particles, thereby leading to wide particle size distribution of the gold powder.

[0034] S2, under stirring, the dispersant solution is quickly added to solution A for the first stage of mixing for 0.5~5 min. Then, the reducing agent solution is quickly added for the second stage of mixing for 0.5~10 min. After that, the morphology optimization agent solution is added dropwise to the reaction system. After the reaction is complete, the precipitate is collected.

[0035] The dispersant is one or more of the following: sodium dodecyl sulfate, polyvinylpyrrolidone, methylcellulose, polyurethane, glyceryl stearate, stearic acid, oleic acid, polyvinyl alcohol, and undecyl mercaptan.

[0036] The reducing agent is one or more of the following: sodium borohydride, hydrazine hydrate, hydrazine hydrochloride, sodium citrate, sodium sulfite, formaldehyde, ascorbic acid, sodium bisulfite, triethanolamine, and hydrazine carbonate.

[0037] The morphology optimizer is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The dropping rate of the morphology optimizer is 10~100mL / min. After the dropping is completed, the reaction time is 5~20min.

[0038] Based on the synergistic treatment of chloroauric acid solution using multiple ligand stabilizers and acidic solutions, a morphology optimizer solution is further added during the reaction process. On the one hand, this is beneficial for generating a large number of tiny and uniform crystal nuclei, resulting in gold powder with uniform size and good monodispersity. On the other hand, it reacts with the dispersant in the chloroauric acid solution, effectively reducing the dispersant content on the surface of the gold powder, thereby significantly reducing the viscosity of the slurry and effectively improving the rheological properties of the slurry.

[0039] S3 involves washing, drying, and dispersing the precipitate to obtain gold powder with high sphericity.

[0040] The washing process includes: first, washing the precipitate with deionized water until the conductivity is <15μS / cm, removing the supernatant to obtain a first precipitate with a water content ≤10%; then, washing the first precipitate with ethanol to remove the supernatant to obtain a second precipitate.

[0041] The drying method is forced air drying. The dispersion treatment is grinding dispersion.

[0042] The preparation method of the high sphericity gold powder provided by the present invention will be described below with reference to specific embodiments. Unless otherwise specified, the raw materials and reagents used in the embodiments of this application were purchased commercially.

[0043] Example 1 This embodiment provides a method for preparing gold powder with high sphericity, specifically including the following steps: S1, Preparation of chloroauric acid solution: Dissolve 1g of chloroauric acid in 200mL of deionized water.

[0044] Preparation of reducing agent solution: Dissolve 1g of sodium citrate in 40mL of deionized water to obtain sodium citrate solution.

[0045] Preparation of dispersant solution: Dissolve 0.05g of methylcellulose in 10mL of deionized water at 50℃ to obtain methylcellulose solution.

[0046] To prepare a mixed solution of ammonia and ethylenediamine: The molar ratio of chloroauric acid to ammonia and ethylenediamine is 1:6. Mix ammonia and ethylenediamine in a volume ratio of 2:1 and dissolve them in 5 mL of deionized water.

[0047] To prepare a hydrochloric acid solution: Dissolve 2 mL of hydrochloric acid in 5 mL of deionized water.

[0048] To prepare a sodium hydroxide solution: Dissolve 0.5g of sodium hydroxide in 100mL of deionized water.

[0049] While stirring, a mixed solution of ammonia and ethylenediamine, and hydrochloric acid solution were added sequentially to chloroauric acid solution to obtain solution A with a pH of 4.2.

[0050] S2, under stirring, the prepared methylcellulose solution is quickly added to solution A and mixed for 1 min. Then, sodium citrate solution is quickly added and mixed for 5 min. Then, sodium hydroxide solution is added dropwise to the reaction system at a rate of 20 mL / min. After the addition is completed, the reaction continues for 10 min, and the precipitate is collected.

[0051] S3. First, the precipitate is washed with deionized water until the conductivity is <15μS / cm, then the supernatant is removed to obtain the first precipitate, which has a water content ≤10%. Then, the first precipitate is washed with ethanol, and the supernatant is removed to obtain the second precipitate. The second precipitate is dried at 30℃ to constant weight, and then ground and dispersed to obtain gold powder.

[0052] SEM image of the gold powder obtained in Example 1 is shown below. Figure 1 As shown, the gold powder exhibits high sphericity and good dispersibility, with a particle size range of 0.3-0.8 μm.

[0053] Example 2 This embodiment provides a method for preparing gold powder with high sphericity, specifically including the following steps: S1, Preparation of chloroauric acid solution: Dissolve 1g of chloroauric acid in 150mL of deionized water.

[0054] Preparation of reducing agent solution: Dissolve 0.5 mL of hydrazine hydrate in 30 mL of deionized water to obtain hydrazine hydrate solution.

[0055] Preparation of dispersant solution: Dissolve 0.1g of polyvinylpyrrolidone in 10mL of deionized water to obtain a polyvinylpyrrolidone solution.

[0056] To prepare a mixed solution of sodium citrate and sodium thiosulfate: The molar ratio of chloroauric acid to sodium citrate and sodium thiosulfate is 1:3. Sodium citrate and sodium thiosulfate are mixed and dissolved in 10 mL of deionized water at a mass ratio of 1:1.

[0057] To prepare a hydrochloric acid solution: Dissolve 1 mL of hydrochloric acid in 5 mL of deionized water.

[0058] To prepare a potassium hydroxide solution: Dissolve 1g of potassium hydroxide in 200mL of deionized water.

[0059] While stirring, a mixed solution of sodium citrate and sodium thiosulfate, and a hydrochloric acid solution were added sequentially to a chloroauric acid solution to obtain solution A with a pH of 4.5.

[0060] S2, under stirring, the polyvinylpyrrolidone solution is rapidly added to solution A and mixed for 5 min. Then, the hydrazine hydrate solution is rapidly added and mixed for 0.5 min. Then, potassium hydroxide solution is added dropwise to the reaction system at a rate of 100 mL / min. After the addition is completed, the reaction continues for 20 min, and the precipitate is collected. S3. First, the precipitate is washed with deionized water until the conductivity is <15μS / cm. Then, the supernatant is removed to obtain the first precipitate, which has a water content ≤10%. The first precipitate is then washed with ethanol to remove the supernatant, resulting in the second precipitate. The second precipitate is dried at 30℃ to constant weight and then ground and dispersed to obtain gold powder.

[0061] SEM image of the gold powder obtained in Example 2 is shown below. Figure 2 As shown, the gold powder exhibits high sphericity and good dispersibility, with a particle size range of 0.3-0.6 μm.

[0062] Example 3 This embodiment provides a method for preparing gold powder with high sphericity, specifically including the following steps: S1, Preparation of chloroauric acid solution: Dissolve 1g of chloroauric acid in 150mL of deionized water.

[0063] Preparation of reducing agent solution: Dissolve 0.6 mL of formaldehyde in 50 mL of deionized water to obtain formaldehyde solution.

[0064] Preparation of dispersant solution: Dissolve 0.15g stearic acid in 5mL ethanol at 50℃ to obtain stearic acid solution.

[0065] To prepare a mixed solution of ammonia and polyethyleneimine: The molar ratio of chloroauric acid to ammonia and polyethyleneimine is 1:5. Mix ammonia and polyethyleneimine in a volume ratio of 1:1 and dissolve them in 10 mL of deionized water.

[0066] To prepare the hydrochloric acid solution: Dissolve 2.2 mL of hydrochloric acid in 5 mL of deionized water.

[0067] Mixed solution of sodium carbonate and potassium carbonate: Dissolve 0.05g of sodium carbonate and 0.1g of potassium carbonate together in 100mL of deionized water.

[0068] While stirring, a mixed solution of ammonia and polyethyleneimine, and hydrochloric acid solution were added sequentially to chloroauric acid solution to obtain solution A with a pH of 4.3.

[0069] S2, under stirring, stearic acid solution is rapidly added to solution A and mixed for 0.5 min, formaldehyde solution is rapidly added to solution A and mixed for 2 min, then a mixed solution of sodium carbonate and potassium carbonate is added dropwise to the reaction system at a rate of 30 mL / min, and the reaction continues for 5 min after the addition is completed to collect the precipitate.

[0070] S3. First, the precipitate is washed with deionized water until the conductivity is <15μS / cm. Then, the supernatant is removed to obtain the first precipitate, which has a water content ≤10%. The first precipitate is then washed with ethanol to remove the supernatant, resulting in the second precipitate. The second precipitate is dried at 30℃ to constant weight and then ground and dispersed to obtain gold powder.

[0071] SEM image of the gold powder obtained in Example 3 is shown below. Figure 3 As shown in the figure, the gold powder exhibits high sphericity and good dispersibility, with a particle size range of 0.3-0.7 μm.

[0072] Comparative Example 1 Comparative Example 1 provides a method for preparing gold powder. Compared with Example 2, the main difference is that sodium thiosulfate is not added in step S1, i.e., a single ligand stabilizer is used, and no acidic solution is added to protect the gold complex, resulting in solution A. Other experimental parameters are basically the same as in Example 2, and will not be repeated here.

[0073] The SEM image of the gold powder obtained in Comparative Example 1 is shown below. Figure 4 As shown, the gold powder has poor sphericity, is too small in size, and exhibits severe agglomeration.

[0074] Comparative Example 2 Comparative Example 2 provides a method for preparing gold powder. The main difference from Example 2 is that no acidic solution (hydrochloric acid solution) is added in step S1. Other experimental parameters are basically the same as in Example 2, and will not be repeated here.

[0075] The SEM image of the gold powder obtained in Comparative Example 2 is shown below. Figure 5 As shown, the gold powder size exhibits polarization, agglomeration, and a significantly broadened particle size distribution.

[0076] Comparative Example 3 Comparative Example 3 provides a method for preparing gold powder. The main difference from Example 2 is that sodium thiosulfate was not added in step S1; that is, a single ligand stabilizer was used. Other experimental parameters are basically the same as in Example 2 and will not be repeated here.

[0077] The SEM image of the gold powder obtained in Comparative Example 3 is shown below. Figure 6 As shown, the gold powder exhibits poor sphericity and severe agglomeration.

[0078] Comparative Example 4 Comparative Example 4 provides a method for preparing gold powder. Compared with Example 2, the main difference is that in step S2, no morphology optimizer (potassium hydroxide solution) is added. Instead, the dispersant solution and reducing agent solution are directly added to solution A under stirring, and the reaction yields a precipitate. Other experimental parameters are basically the same as in Example 2, and will not be repeated here.

[0079] The SEM image of the gold powder obtained in Comparative Example 4 is shown below. Figure 7 As shown, the gold powder has poor sphericity, exhibits agglomeration, and has a wide particle size distribution.

[0080] The properties of the gold powders prepared in Examples 1-3 and Comparative Examples 1-4 are shown in Table 1.

[0081] Table 1 Comparing Example 2 with Comparative Example 1, it can be seen that using only a single ligand stabilizer and without adding an acidic solution to protect the gold complex resulted in poor sphericity, excessively small size, and severe agglomeration of the gold powder.

[0082] Comparing Example 2 with Comparative Example 2, it can be seen that the absence of acidic solution leads to polarization of gold powder size, agglomeration, and a significantly widened particle size distribution.

[0083] Comparing Example 2 with Comparative Example 3, it can be seen that using only a single ligand stabilizer results in poor sphericity and severe agglomeration of the gold powder.

[0084] Comparing Example 2 with Comparative Example 4, it can be seen that without the addition of morphology optimizer, the gold powder has poor sphericity, agglomeration, and a wide particle size distribution.

[0085] Examples 4-5 and Comparative Examples 5-6 Examples 4-5 and Comparative Examples 5-6 provide a method for preparing gold powder with high sphericity. The difference from Example 2 is that in step S1, the molar ratio of chloroauric acid in the chloroauric acid solution to the ligand stabilizer in the multiple ligand stabilizer solution is different; as shown in Table 2 below; the rest is roughly the same as in Example 1, and will not be repeated here.

[0086] Table 2 Experiments show that when the molar ratio of chloroauric acid to multiple ligand stabilizers is in the range of 1:(1-10), spherical gold powder with high sphericity and high dispersibility can be obtained, and the size of the gold powder increases with the increase of the ratio. When the molar ratio is greater than 1:1, the gold powder has poor sphericity, irregular morphology, and serious agglomeration. When the molar ratio is less than 1:10, there are large gold powder particles, small gold powder particles are agglomerated, and the overall particle size distribution becomes wider.

[0087] It should be noted that the multiligand stabilizer solution may include at least two of the following: ammonia, ethylenediamine, polyethyleneimine, triethylamine, sodium thiosulfate, sodium citrate, sodium iodide, methylamine, n-propylamine, and 4-dimethylaminepyridine.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing high sphericity gold powder, characterized in that, Includes the following steps: S1, under stirring, a multiple ligand stabilizer solution and an acidic solution are added sequentially to the chloroauric acid solution to adjust the pH of the reaction system to 4.0-5.0, resulting in solution A; the multiple ligand stabilizer solution includes at least two of ammonia, ethylenediamine, polyethyleneimine, triethylamine, sodium thiosulfate, sodium citrate, sodium iodide, methylamine, n-propylamine, and 4-dimethylaminepyridine; S2, under stirring, the dispersant solution is quickly added to solution A for the first stage of mixing, followed by the rapid addition of the reducing agent solution for the second stage of mixing; then, the morphology optimizing agent solution is added dropwise to the reaction system, and the precipitate is collected after the reaction is complete; S3, the precipitate is washed, dried and dispersed to obtain gold powder with high sphericity.

2. The method for preparing high sphericity gold powder according to claim 1, characterized in that: In step S1, the molar ratio of chloroauric acid in the chloroauric acid solution to the ligand stabilizer in the multiple ligand stabilizer solution is 1:(1-10).

3. The method for preparing high sphericity gold powder according to claim 1, characterized in that: The acidic solution is one or more of hydrochloric acid, citric acid, oxalic acid, and acetic acid.

4. The method for preparing high sphericity gold powder according to claim 1, characterized in that: In step S2, the dispersant is one or more of sodium dodecyl sulfate, polyvinylpyrrolidone, methylcellulose, polyurethane, glyceryl stearate, stearic acid, oleic acid, polyvinyl alcohol, and undecyl mercaptan.

5. The method for preparing high sphericity gold powder according to claim 1, characterized in that: The mixing time for the first stage is 0.5 to 5 minutes.

6. The method for preparing high sphericity gold powder according to claim 1, characterized in that: The reducing agent is one or more of sodium borohydride, hydrazine hydrate, hydrazine hydrochloride, sodium citrate, sodium sulfite, formaldehyde, ascorbic acid, sodium bisulfite, triethanolamine, and hydrazine carbonate.

7. The method for preparing high sphericity gold powder according to claim 1, characterized in that: The mixing time for the second stage is 0.5 to 10 minutes.

8. The method for preparing high sphericity gold powder according to claim 1, characterized in that: The morphology optimizer is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate, and the dropping rate of the morphology optimizer is 10~100mL / min; the reaction time after dropping is 5~20min.

9. The method for preparing high sphericity gold powder according to claim 1, characterized in that: The washing process includes: first, washing the precipitate with deionized water until the conductivity is <15μS / cm, removing the supernatant to obtain a first precipitate with a water content ≤10%; then, washing the first precipitate with ethanol to remove the supernatant to obtain a second precipitate.

10. The method for preparing high sphericity gold powder according to claim 1, characterized in that: In step S3, the drying method is blower drying; the dispersion treatment is grinding dispersion.

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