CN114160803A - High-efficiency preparation method of high-dispersity spherical gold powder - Google Patents
High-efficiency preparation method of high-dispersity spherical gold powder Download PDFInfo
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- CN114160803A CN114160803A CN202111361261.2A CN202111361261A CN114160803A CN 114160803 A CN114160803 A CN 114160803A CN 202111361261 A CN202111361261 A CN 202111361261A CN 114160803 A CN114160803 A CN 114160803A
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- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
Abstract
The invention discloses an efficient preparation method of high-dispersity spherical gold powder. The method has the advantages of few process steps, simple operation, short production period, good product uniformity and dispersibility, and can be used for batch production of the spherical superfine gold powder.
Description
Technical Field
The invention belongs to the field of fine chemical engineering, and particularly relates to an efficient preparation method of micron-sized spherical gold powder for conductive paste.
Background
Low temperature co-fired ceramic (LTCC) is a novel multilayer substrate process technology, is widely applied to the field of military electronic equipment due to high component density, interconnection line segments and excellent performance, and is restricted by the development of military LTCC technology due to the fact that gold conductive slurry is used as an important conductive raw material. The gold powder is used as a functional phase in the gold conductor slurry, and the particle morphology, the dispersibility and the uniformity of the gold powder have great influence on the sintering performance and the sintering matching property of the slurry. Generally, the smoother the surface of gold powder particles is, the more beneficial the improvement of printing performance is, the less organic carriers are adsorbed on the smooth surface, and the shrinkage rate of a conductor film during drying and sintering can be reduced.
The traditional preparation method of the spherical gold powder is to dissolve the gold powder in aqua regia, then to continue to add hydrochloric acid to fully remove nitrate to prepare chloroauric acid solution, and to reduce chloroauric acid by selecting different dispersants and reducing agents under certain conditions to obtain the gold powder.
The method has the problems of long nitrate removing process, poor operation environment, low gold yield and the like, and the parameters of the dispersing agent, the reducing agent, the addition rate and the like as main factors influencing the sphericity, the particle size distribution, the dispersity and the like of a final product have certain optimization space.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the efficient preparation method of the spherical superfine gold powder, which is convenient for large-scale production.
The technical scheme adopted by the invention for solving the technical problems is as follows: the high-efficiency preparation method of the high-dispersity spherical gold powder sequentially comprises the following steps
(1) Placing 50-200 g of gold blocks serving as raw materials into a three-neck flask, adding a prepared aqua regia solution into the three-neck flask, and stirring for 0.5-1 h to fully dissolve the gold blocks;
(2) adding distilled water into the gold solution obtained in the step (1) to dilute the gold solution until the concentration of gold is 0.05-0.3 mol/L, slowly adding ammonia water into the gold solution at the temperature of 27-37 ℃, adjusting the pH to 8.04-8.69 to form a light yellow suspension, and then adding a little hydrochloric acid to adjust the pH to 3.5-3.93;
(3) and (3) when the temperature of the suspension obtained by the reaction is reduced to room temperature, adding a reaction solution into the suspension according to the mass ratio of polyvinylpyrrolidone to gold powder of 0.1-0.5: 1, adding a polyvinylpyrrolidone aqueous solution as a dispersing agent, and fully stirring;
(4) preparing a reducing agent solution, keeping the temperature of the suspension liquid in the step (3) at 25-35 ℃, rapidly adding an aqueous solution of ascorbic acid and hydrazine hydrate at a speed of 200-400 ml/min to serve as a reducing solution, stopping adding after adding half of the reducing solution, continuously stirring for 5-20 minutes to form a gray suspension, continuously adding the rest of the reducing solution, and fully stirring for 0.5-2 hours until a tawny precipitate is generated;
(5) carrying out suction filtration and separation on the precipitate obtained in the step (4), washing twice with distilled water, washing once with alcohol, then adding oleic acid for dispersion treatment for 20 min, transferring to an oven for blowing and drying at 55-60 ℃ for 6h, and crushing the dried gold powder to obtain the gold powder with the particle size of 1.2-1.8 mu m and the specific surface area of 0.20-0.24 m2A spherical gold powder with smooth surface.
The high-efficiency preparation method of the high-dispersity spherical gold powder is characterized in that the concentration of concentrated nitric acid for preparing aqua regia in the step (1) is 65-68%, and 15-30 mL of concentrated nitric acid is added into every 10g of gold blocks; the concentration of the concentrated hydrochloric acid is 36-38%, and 45-90 mL of concentrated hydrochloric acid is added into every 10g of gold blocks.
The high-efficiency preparation method of the high-dispersity spherical gold powder is characterized in that the concentration of ammonia water in the step (2) is 25-28%.
The efficient preparation method of the high-dispersity spherical gold powder is characterized in that the next step is carried out after the dispersing agent in the step (3) is added and stirred for at least 10 minutes.
The high-efficiency preparation method of the high-dispersity spherical gold powder is characterized in that the reducing solution in the step (4) is ascorbic acid and hydrazine hydrate with the concentration of 38%, and the weight ratio of the reducing solution to the reducing solution is that the reducing solution is prepared from 1 g: 0.1-0.3 mL of solution prepared by dissolving in water.
The invention has the beneficial effects that:
the invention adopts the solution formed by dissolving gold in aqua regia as the reaction mother solution directly, and compared with the prior art, the invention removes the nitrate removing process and shortens the reaction time. The whole reaction system can be carried out at normal temperature, a series of potential safety hazards and energy waste caused by heating can be avoided, then the sufficient nucleation time of the gold particles is effectively optimized by controlling the addition amount of the dispersing agent, the gold concentration of the reaction system and the method of adding the reducing agent in sections, the sphericity and the uniformity of the prepared superfine gold powder are improved, the reduction degree of gold ions is improved by adopting a mixed reducing agent solution, so that the yield is improved, and the prepared gold powder is subjected to dispersion treatment by adopting an organic acid solution, so that the prepared gold powder has better dispersibility.
The yield of the spherical gold powder preparation method adopted by the invention can reach more than 99%, the formed gold powder has high sphericity, smooth surface, uniform particle size and good dispersibility, the period for synthesizing a batch of samples can be controlled within 12 hours, the whole process does not need heating, the nitrate removing yield is high, and the large-scale production is convenient.
Drawings
FIG. 1 is a schematic flow chart of the production process of the present invention;
FIG. 2 is a scanning electron microscope image of the ultrafine gold powder prepared in example 1 of the present invention;
FIG. 3 is a scanning electron microscope image of the ultrafine gold powder prepared in example 2 of the present invention;
FIG. 4 is a scanning electron microscope image of the ultrafine gold powder prepared in example 3 of the present invention.
Detailed Description
The invention is further described with reference to the accompanying drawings and specific embodiments.
The invention aims to prepare the superfine spherical gold powder by using gold lumps as raw materials, completely dissolving the gold lumps with aqua regia and directly using the gold lumps as subsequent reaction mother liquor, saving the time consumed by nitrate removal, effectively optimizing the sphericity, the dispersibility and the uniformity of the prepared superfine gold powder by controlling the addition amount of a dispersing agent, the gold concentration of a reaction system and a method of adding a mixed reducing agent solution in sections, and dispersing the prepared gold powder by using an organic acid solution to ensure that the prepared gold powder has better dispersibility. In conclusion, the method has simple and safe process and good product dispersibility, uniformity and surface smoothness, and can be used for batch production of the ultrafine spherical gold powder for LTCC.
Example 1
50g of gold blocks are put into a three-neck flask, 375ml of aqua regia prepared by hydrochloric acid and 125ml of nitric acid is added, and the mixture is stirred and dissolved for 0.5 h. The solution obtained after the gold powder was completely dissolved was diluted to 2500ml with water, and then ammonia was added thereto at 34 ℃ to adjust the pH to 8.26, followed by hydrochloric acid to adjust the pH to 3.80. Weighing 5g of polyvinylpyrrolidone, dissolving the polyvinylpyrrolidone in water, adding the polyvinylpyrrolidone into a gold solution, fully stirring, weighing 100g of ascorbic acid and 10mL of hydrazine hydrate, dissolving the ascorbic acid and the hydrazine hydrate in 200mL of water, dropwise adding 100mL (200 mL/min) of the ascorbic acid and the hydrazine hydrate into the gold solution, reacting for 20 minutes, dropwise adding the residual reducing agent solution, stirring for 1 hour, generating brown precipitates, precipitating at the bottom of a container, carrying out suction filtration, washing for 2 times (the suction filtration is quick, and the filtrate is colorless and transparent), washing for 1 time with alcohol, then adding oleic acid for dispersion treatment for 20 minutes, transferring the mixture into an oven, and carrying out air blast drying (6 hours) at 55 ℃. The scanning picture of the obtained brown product is shown as the following figure, the particle diameter of the ball powder prepared by the scheme is 1.2-1.8 mu m, and the specific surface area is 0.20m2The yield reaches 99.2 percent per gram.
Example 2
100g of gold lumps are taken in a three-neck flask, 600ml of hydrochloric acid and 200ml of aqua regia prepared by nitric acid are added, and stirred for 1 hour to be dissolved. After the gold powder was completely dissolved, the resulting solution was diluted to 4000ml, and ammonia water was added thereto at 27 ℃ to adjust the pH to 8.04, followed by hydrochloric acid to adjust the pH to 3.93. Weighing 25g of polyvinylpyrrolidone, dissolving the polyvinylpyrrolidone in water, adding the polyvinylpyrrolidone into a gold solution, fully stirring, weighing 240g of ascorbic acid and 50mL of hydrazine hydrate, dissolving the ascorbic acid and the hydrazine hydrate in 400mL of water, dropwise adding 200mL (300 mL/min) of the ascorbic acid and the hydrazine hydrate into the gold solution, reacting for 20 minutes, dropwise adding the rest reducing agent solution, stirring for 1 hour to generate brown precipitate, precipitating the brown precipitate at the bottom of a container, carrying out suction filtration, washing for 2 times (the suction filtration is quick, and the filtrate is colorless and transparent), washing for 1 time with alcohol, then adding oleic acid for dispersion treatment for 20 minutes, transferring the product into an oven, and carrying out air blast drying at 60 ℃ (6 hours). The scanning picture of the obtained brown product is shown in figure 2, the particle diameter of the ball powder prepared by the scheme is 1.2-1.8 mu m, and the specific surface area is 0.21m2The yield reaches 99.6 percent per gram.
Example 3
Putting 200g gold block into three-neck flask, adding 1050mL hydrochloric acid and 350mL aqua regia prepared from nitric acid, stirring for 45min to dissolve. After the gold powder was completely dissolved, the resulting solution was diluted to 9000ml, and ammonia water was added thereto at 37 ℃ to adjust the pH to 8.69, followed by adding hydrochloric acid to adjust the pH to 3.50. Weighing 40g of polyvinylpyrrolidone, dissolving the polyvinylpyrrolidone in water, adding the polyvinylpyrrolidone into a gold solution, fully stirring, weighing 400g of ascorbic acid and 100mL of hydrazine hydrate, dissolving the ascorbic acid and 100mL of hydrazine hydrate in 1000mL of water, dropwise adding 500mL (400 mL/min) of the ascorbic acid and the hydrazine hydrate into the gold solution, reacting for 20 minutes, dropwise adding the rest reducing agent solution, stirring for 45 minutes to generate brown precipitate, precipitating the brown precipitate at the bottom of a container, carrying out suction filtration, washing for 2 times (the suction filtration is quick, and the filtrate is colorless and transparent), washing for 1 time with alcohol, then adding oleic acid for dispersion treatment for 20 minutes, transferring the product into an oven, and carrying out air blast drying at 60 ℃ (6 hours). The scanning picture of the obtained brown product is shown in figure 3, the particle diameter of the ball powder prepared by the scheme is 1.2-1.8 mu m, and the specific surface area is 0.24m2The yield reaches 99.4 percent per gram.
The above-described embodiments are merely illustrative of the principles and effects of the present invention, and some embodiments may be applied, and it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the inventive concept of the present invention, and these embodiments are within the scope of the present invention.
Claims (5)
1. A high-efficiency preparation method of high-dispersity spherical gold powder is characterized by comprising the following steps: sequentially comprises the following steps
(1) Placing 50-200 g of gold blocks into a three-neck flask, adding aqua regia solution, and stirring for 0.5-1 h to fully dissolve;
(2) adding distilled water into the gold solution obtained in the step (1) to dilute the gold solution until the concentration of gold is 0.05-0.3 mol/L, slowly adding ammonia water into the gold solution at the temperature of 27-37 ℃, adjusting the pH to form a light yellow suspension, and then adding hydrochloric acid to adjust the pH to 3.5-3.93;
(3) when the temperature of the suspension is reduced to room temperature, adding the following components in a mass ratio of polyvinylpyrrolidone to gold powder of 0.1-0.5: 1, adding a polyvinylpyrrolidone aqueous solution as a dispersing agent, and fully stirring;
(4) keeping the temperature of the suspension in the step (3) at 25-35 ℃, adding an aqueous solution of ascorbic acid and hydrazine hydrate as a reducing solution at a speed of 200-400 ml/min, stopping adding after adding half of the reducing solution, continuously stirring for 5-20 minutes to form a gray suspension, continuously adding the rest of the reducing solution, and fully stirring for 0.5-2 hours until a tawny precipitate is generated;
(5) carrying out suction filtration separation on the precipitate obtained in the step (4), washing with distilled water and alcohol, then adding oleic acid for dispersion treatment for 20 min, transferring the precipitate to an oven for blowing drying at 55-60 ℃ for 6h, and crushing the dried gold powder to obtain the gold powder with the particle size of 1.2-1.8 mu m and the specific surface area of 0.20-0.24 m2A spherical gold powder with smooth surface.
2. The efficient preparation method of high-dispersity spherical gold powder according to claim 1, wherein the concentration of concentrated nitric acid for preparing aqua regia in the step (1) is 65-68%, and 15-30 mL of concentrated nitric acid is added into each 10g of gold block; the concentration of the concentrated hydrochloric acid is 36-38%, and 45-90 mL of concentrated hydrochloric acid is added into every 10g of gold blocks.
3. The method for efficiently preparing highly dispersible spherical gold powder according to claim 1, wherein the concentration of ammonia water in step (2) is 25-28%.
4. The method for efficiently preparing highly dispersible spherical gold powder according to claim 1, wherein the dispersant in step (3) is added and then stirred for at least 10 minutes before proceeding to the next step.
5. The method for efficiently preparing highly dispersible spherical gold powder according to claim 1, wherein the reducing solution in step (4) is ascorbic acid and 38% hydrazine hydrate in a ratio of 1 g: 0.1-0.3 mL of solution prepared by dissolving in water.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115026300A (en) * | 2022-07-12 | 2022-09-09 | 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） | Preparation method of spherical gold powder for conductive paste |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001240904A (en) * | 2000-03-01 | 2001-09-04 | Dowa Mining Co Ltd | Production method for copper powder small in grain size distribution |
| CN1806972A (en) * | 2005-01-19 | 2006-07-26 | 中国科学院化学研究所 | Method for preparing gold nano microgranule powder |
| JP2006233252A (en) * | 2005-02-23 | 2006-09-07 | Mitsubishi Materials Corp | Wire-shaped gold particulate, method for producing the same, composition comprising the same and application thereof |
| CN103192090A (en) * | 2013-04-11 | 2013-07-10 | 贵研铂业股份有限公司 | Liquid-phase preparation method of monodisperse spherical gold, platinum and palladium alloy powder |
| US20140113810A1 (en) * | 2011-03-04 | 2014-04-24 | Shogo Shirakawa | Metal particles, exhaust gas purifying catalyst comprising metal particles, and methods for producing them |
| CN104289728A (en) * | 2014-10-23 | 2015-01-21 | 苏州华冲精密机械有限公司 | Preparation method of spherical superfine gold powder for electronic materials |
| JP2015105413A (en) * | 2013-11-29 | 2015-06-08 | 住友金属鉱山株式会社 | Method for manufacturing gold powder with high bulk density |
| CN105014092A (en) * | 2014-04-29 | 2015-11-04 | 尤静 | Preparation method for gold nanoparticles capable of being dispersed in water phase and organic phase |
| CN105965030A (en) * | 2016-06-20 | 2016-09-28 | 昆山鸿福泰环保科技有限公司 | Technique for recovering gold from gold iodide liquid waste |
| CN106270545A (en) * | 2015-06-12 | 2017-01-04 | 中国振华集团云科电子有限公司 | A kind of high-tap density noble metal raw powder's production technology |
| WO2017043837A1 (en) * | 2015-09-10 | 2017-03-16 | 엘에스니꼬동제련 주식회사 | Method for preparing silver powder using silver grains |
| CN107790739A (en) * | 2016-08-29 | 2018-03-13 | 江苏永佳电子材料有限公司 | A kind of preparation method of electronic material ultrafine gold powder |
| CN107866562A (en) * | 2017-12-15 | 2018-04-03 | 湖南纳科新材料科技有限公司 | A kind of spherical golden micro mist and its preparation method and application |
| CN109382508A (en) * | 2017-08-10 | 2019-02-26 | 西安宏星电子浆料科技有限责任公司 | A kind of electric slurry spherical gold powder and preparation method thereof |
-
2021
- 2021-11-17 CN CN202111361261.2A patent/CN114160803A/en active Pending
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001240904A (en) * | 2000-03-01 | 2001-09-04 | Dowa Mining Co Ltd | Production method for copper powder small in grain size distribution |
| CN1806972A (en) * | 2005-01-19 | 2006-07-26 | 中国科学院化学研究所 | Method for preparing gold nano microgranule powder |
| JP2006233252A (en) * | 2005-02-23 | 2006-09-07 | Mitsubishi Materials Corp | Wire-shaped gold particulate, method for producing the same, composition comprising the same and application thereof |
| US20140113810A1 (en) * | 2011-03-04 | 2014-04-24 | Shogo Shirakawa | Metal particles, exhaust gas purifying catalyst comprising metal particles, and methods for producing them |
| CN103192090A (en) * | 2013-04-11 | 2013-07-10 | 贵研铂业股份有限公司 | Liquid-phase preparation method of monodisperse spherical gold, platinum and palladium alloy powder |
| JP2015105413A (en) * | 2013-11-29 | 2015-06-08 | 住友金属鉱山株式会社 | Method for manufacturing gold powder with high bulk density |
| CN105014092A (en) * | 2014-04-29 | 2015-11-04 | 尤静 | Preparation method for gold nanoparticles capable of being dispersed in water phase and organic phase |
| CN104289728A (en) * | 2014-10-23 | 2015-01-21 | 苏州华冲精密机械有限公司 | Preparation method of spherical superfine gold powder for electronic materials |
| CN106270545A (en) * | 2015-06-12 | 2017-01-04 | 中国振华集团云科电子有限公司 | A kind of high-tap density noble metal raw powder's production technology |
| WO2017043837A1 (en) * | 2015-09-10 | 2017-03-16 | 엘에스니꼬동제련 주식회사 | Method for preparing silver powder using silver grains |
| CN105965030A (en) * | 2016-06-20 | 2016-09-28 | 昆山鸿福泰环保科技有限公司 | Technique for recovering gold from gold iodide liquid waste |
| CN107790739A (en) * | 2016-08-29 | 2018-03-13 | 江苏永佳电子材料有限公司 | A kind of preparation method of electronic material ultrafine gold powder |
| CN109382508A (en) * | 2017-08-10 | 2019-02-26 | 西安宏星电子浆料科技有限责任公司 | A kind of electric slurry spherical gold powder and preparation method thereof |
| CN107866562A (en) * | 2017-12-15 | 2018-04-03 | 湖南纳科新材料科技有限公司 | A kind of spherical golden micro mist and its preparation method and application |
Non-Patent Citations (2)
| Title |
|---|
| 杨新伟;张贵荣;李永绣;徐柏庆;: "单分散纳米金尺寸的分步晶种生长控制", 物理化学学报 * |
| 赵科良;田发香;王大林;赵莹;陆冬梅;: "亚微米球形金粉的制备与应用", 电子元件与材料 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115026300A (en) * | 2022-07-12 | 2022-09-09 | 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） | Preparation method of spherical gold powder for conductive paste |
| CN115026300B (en) * | 2022-07-12 | 2023-11-03 | 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） | Preparation method of spherical gold powder for conductive paste |
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