CN105710387A - Process for producing silver powder through liquid phase reduction method - Google Patents
Process for producing silver powder through liquid phase reduction method Download PDFInfo
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- CN105710387A CN105710387A CN201610120347.9A CN201610120347A CN105710387A CN 105710387 A CN105710387 A CN 105710387A CN 201610120347 A CN201610120347 A CN 201610120347A CN 105710387 A CN105710387 A CN 105710387A
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- argentum powder
- silver nitrate
- nitrate solution
- solution
- liquid phase
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- 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 a process for producing silver powder through a liquid phase reduction method. The process includes the following steps that a, a silver salt solution is prepared; b, the silver powder is prepared, wherein a silver nitrate solution is firstly heated to 35 DEG C to 40 DEG C, and then an alkaline matter solution is added; the silver nitrate solution is continuously heated to 47 DEG C to 53 DEG C, and a dispersing agent is added; the silver nitrate solution is continuously heated to 58 DEG C to 61 DEG C, and a reducing agent is added; and an initial silver powder product is obtained until a chemical reaction in the silver nitrate solution is complete; and c, the silver powder is washed, wherein deionized water is added into a reaction still, the initial silver powder product is thoroughly washed and dried, and silver powder finished products are obtained. The process is used for producing the silver powder, losses of the silver powder in the washing process are greatly reduced, the yield of the silver powder is improved, waste of silver resources is reduced, and the production cost of an enterprise is reduced.
Description
Technical field
The present invention relates to argentum powder production field, be specifically related to a kind of technique adopting liquid phase reduction to produce argentum powder.
Background technology
Flourish along with electronics industry, the demand of conductive material is also increasing.Argentum powder, as a kind of noble metal powder most widely used in electronics industry, is the basic function material making the electric slurries such as thick film, resistance, pottery, medium.Therefore, the preparation for argentum powder is just particularly important.
For the preparation method of argentum powder, silver nitrate is prepared into the argentum powder meeting target component by the modal chemical reduction reaction that is through.After chemical reduction reaction terminates, owing to containing substantial amounts of impurity in argentum powder, it is necessary to deionized water, argentum powder is washed, after argentum powder precipitates in reactor, then extract the supernatant.Washing precipitation extracts clear liquid, and such program need to be repeatedly performed for several times, till electrical conductivity of water after washing is less than the setting of technique.
In now common argentum powder preparation technology, adopting acid and alkali-resistance suction pump to extract supernatant water after washing silver powder precipitation, during extraction, owing to suction pump suction is relatively big, argentum powder runs off more.Also there is the cleaning process of the argentum powder after improvement, without acid and alkali-resistance suction pump, but utilize siphon principle, directly extract the supernatant with water pipe, so can greatly reduce the loss of argentum powder when extracting clear liquid.But, siphon principle is utilized to extract the supernatant, when drawing water close to the position that argentum powder precipitates, owing to silver powder particles is only small, having bigger siphon strength near the mouth of pipe that draws water, argentum powder is still easily taken away by drinking-water pipe, argentum powder small part is run off, the input and output rate of such argentum powder can only achieve about 98%, wastes silver resource, adds the production cost of enterprise.
Chinese invention patent, publication number is: CN104325151A, and name is called: a kind of silver powder preparation method, owing to when cleaning argentum powder just finished product, not taking protective measure, it is possible to cause that argentum powder runs off more serious, productivity compared with, cause the drawback that production cost is higher.It is thus desirable to the production technology of argentum powder is further improved.
Summary of the invention
For above the deficiencies in the prior art, it is provided that a kind of technique producing argentum powder with liquid phase reduction reducing the loss of argentum powder, the productivity of raising argentum powder, reduction argentum powder production cost.
Realizing the technical scheme is that a kind of technique adopting liquid phase reduction to produce argentum powder, the method comprises the steps:
A, silver salt solution preparation: being dissolved in deionized water by silver nitrate, prepared concentration is the silver nitrate solution of 0.5～1.5mol/L, then inserts in reactor stand-by by described silver nitrate solution；
B, argentum powder preparation: first described silver nitrate solution is heated to 35～40 DEG C, is subsequently adding alkaline substance solution；Then continue to heat described silver nitrate solution to 47～53 DEG C, add dispersant；Continue again heating described silver nitrate solution to 58～61 DEG C, add reducing agent；Until the chemical reaction in described silver nitrate solution is complete, obtain argentum powder just finished product；
C, argentum powder cleaning: in described reactor, 1., first add deionized water, described argentum powder just finished product washed, then stands；2., after the argentum powder in described reactor is precipitated to lower floor, recycle siphon principle, extract the supernatant in described reactor with siphon；3., when described siphon draws water close to the position that argentum powder precipitates, a plate washer with groove is placed at described siphon tube inlet place；Upward, described siphonal entrance is placed in the groove of described baffle plate the groove of described baffle plate；The upper end-face edge of described groove is higher than the position of described argentum powder precipitation and lower than liquid level；When the liquid level in described reactor is lower than the upper end-face edge of the groove of described baffle plate, repeat aforementioned process 1., 2., 3. 5～7 times；Finally dry, obtain argentum powder finished product.
Preferably, in order to enable quickly the silver ion in described silver nitrate solution to be become fixing silver compound completely, in described step b, described alkaline substance solution is concentration is 5～6.5mol/L sodium hydroxide solution；When adding sodium hydroxide solution, the temperature of described silver nitrate solution is 37 DEG C；The volume ratio of described sodium hydroxide solution and described silver nitrate solution is 18～22:100.
Preferably, in order to prevent described Solid Silver compound from assembling, in described step b, described dispersant is one or more the mixture in polyvinylpyrrolidone, gelatin, monoethanolamine, diethanolamine and triethanolamine.
Preferably, in order to be relatively uniformly dispersed throughout in solution by the silver compound of described solid, in described step b, the described dispersant of addition is gelatin；When adding gelatin, the temperature of described silver nitrate solution is 50 DEG C；The volume ratio of the quality of described gelatin and described silver nitrate solution is 0.8～1g/1L.
Preferably, for the ease of Ag-containing compound is reduced into argentum powder, in described step b, described reducing agent is the one in aluminum, ferrum, zinc, copper, formic acid, formates, hydrazine hydrate, aldehydes, amine, alcohols, glucose, fatty acid or ascorbic acid.
Preferably, in order to quick, convenient, fully Ag-containing compound is reduced into argentum powder, in described step b, described reducing agent is hydrazine hydrate；When adding hydrazine hydrate, the temperature of described silver nitrate solution is 60 DEG C；The volume ratio of described hydrazine hydrate and described silver nitrate solution is 2～4/100.
Preferably, in order to prevent argentum powder from assembling, in described step c, the argentum powder after described cleaning before baking, is also added into the glass dust that granularity is 1～2um；The mass ratio of the silver nitrate being dissolved in deionized water in the glass dust of described addition and described step a is 0.3～0.6:100.
The beneficial effects of the present invention is: the technique that employing liquid phase reduction provided by the present invention produces argentum powder, water owing to, in the cleaning process of argentum powder, make use of siphon principle, after adopting siphon to get rid of washing argentum powder, simplify production equipment, save production cost；The most important thing is, when described siphon draws water close to the position that argentum powder precipitates, a plate washer with groove is placed at described siphon tube inlet place, reduce the siphon power at siphon tube inlet place, greatly reduce the loss of argentum powder during draining, the output capacity making argentum powder can reach more than 98.5%, greatly reduces the cost of enterprise.
Detailed description of the invention
Below the technical scheme in the embodiment of the present invention is clearly and completely described.Based on the embodiment in the present invention, the every other embodiment that those skilled in the art obtain under not making creative work premise, broadly fall into the scope of protection of the invention.
Embodiment 1
The step producing argentum powder 1 is as follows:
A, silver salt solution preparation: being dissolved in deionized water by the silver nitrate of 50 weight portions, prepared concentration is the silver nitrate solution of 0.5mol/L, then inserts in reactor stand-by；
B, argentum powder preparation: first described silver nitrate solution is heated to 35 DEG C, is subsequently adding 5mol/L sodium hydroxide solution；Then continue to heat described silver nitrate solution to 47 DEG C, now can produce Solid Silver compound, in order to prevent Solid Silver compound from assembling, can be realized by addition dispersant, described dispersant is one or more the mixture in polyvinylpyrrolidone, gelatin, monoethanolamine, diethanolamine and triethanolamine, and what add in the present embodiment is gelatin；Continue again heating described silver nitrate solution to 58 DEG C, it is subsequently adding reducing agent, carry out reduction reaction, reducing agent can be the one in conventional aluminum, ferrum, zinc, copper, formic acid, formates, hydrazine hydrate, aldehydes, amine, alcohols, glucose, fatty acid or ascorbic acid can, the present embodiment adds hydrazine hydrate；Until the chemical reaction in described silver nitrate solution is complete, obtain argentum powder just finished product；The described sodium hydroxide solution added and the volume ratio of described silver nitrate solution are 18:100；The quality of described gelatin added and the volume ratio of described silver nitrate solution are 0.8g/1L；The described hydrazine hydrate added and the volume ratio of described silver nitrate solution are 2/100；
C, argentum powder cleaning: in described reactor, 1., first add deionized water, described argentum powder just finished product washed, then stands；2., after the argentum powder in described reactor is precipitated to lower floor, recycle siphon principle, extract the supernatant in described reactor with siphon；3., when described siphon draws water close to the position that argentum powder precipitates, a plate washer with groove is placed at described siphon tube inlet place；Upward, described siphonal entrance is placed in the groove of described baffle plate the groove of described baffle plate；The upper end-face edge of described groove is higher than the position of described argentum powder precipitation and lower than liquid level；When the liquid level in described reactor is lower than the upper end-face edge of the groove of described baffle plate, repeat aforementioned process 1., 2., 3. 5 times；Finally adding the glass dust that granularity is 1um of 0.3 weight portion, stir post-drying, obtains finished product.
Embodiment 2
The production stage of argentum powder 2 is as follows:
A, silver salt solution preparation: being dissolved in deionized water by the silver nitrate of 50 weight portions, prepared concentration is the silver nitrate solution of 1.0mol/L, then inserts in reactor stand-by；
B, argentum powder preparation: first described silver nitrate solution is heated to 37 DEG C, is subsequently adding 5.5mol/L sodium hydroxide solution；Then continue to heat described silver nitrate solution to 50 DEG C, add gelatin；Continue again heating described silver nitrate solution to 60 DEG C, add triethanolamine；Until the chemical reaction in described silver nitrate solution is complete, obtain argentum powder just finished product；The described sodium hydroxide solution added and the volume ratio of described silver nitrate solution are 20:100；The quality of described gelatin added and the volume ratio of described silver nitrate solution are 0.9g/1L；The described triethanolamine added and the volume ratio of described silver nitrate solution are 3/100；
C, argentum powder cleaning: in described reactor, 1., first add deionized water, described argentum powder just finished product washed, then stands；2., after the argentum powder in described reactor is precipitated to lower floor, recycle siphon principle, extract the supernatant in described reactor with siphon；3., when described siphon draws water close to the position that argentum powder precipitates, a plate washer with groove is placed at described siphon tube inlet place；Upward, described siphonal entrance is placed in the groove of described baffle plate the groove of described baffle plate；The upper end-face edge of described groove is higher than the position of described argentum powder precipitation and lower than liquid level；When the liquid level in described reactor is lower than the upper end-face edge of the groove of described baffle plate, repeat aforementioned process 1., 2., 3. 6 times；Finally adding the glass dust that granularity is 1.5um of 0.2 parts by weight, stir post-drying, obtains finished product.
Embodiment 3
The production stage of argentum powder 3 is as follows:
A, silver salt solution preparation: being dissolved in deionized water by the silver nitrate of 50 weight portions, prepared concentration is the silver nitrate solution of 1.5mol/L, then inserts in reactor stand-by；
B, argentum powder preparation: first described silver nitrate solution is heated to 40 DEG C, is subsequently adding 6.5mol/L sodium hydroxide solution；Then continue to heat described silver nitrate solution to 53 DEG C, add gelatin；Continue again heating described silver nitrate solution to 61 DEG C, add triethanolamine；Until the chemical reaction in described silver nitrate solution is complete, obtain argentum powder just finished product；The described sodium hydroxide solution added and the volume ratio of described silver nitrate solution are 22:100；The quality of described gelatin added and the volume ratio of described silver nitrate solution are 1.0g/1L；The described triethanolamine added and the volume ratio of described silver nitrate solution are 4/100；
C, argentum powder cleaning: in described reactor, 1., first add deionized water, described argentum powder just finished product washed, then stands；2., after the argentum powder in described reactor is precipitated to lower floor, recycle siphon principle, extract the supernatant in described reactor with siphon；3., when described siphon draws water close to the position that argentum powder precipitates, a plate washer with groove is placed at described siphon tube inlet place；Upward, described siphonal entrance is placed in the groove of described baffle plate the groove of described baffle plate；The upper end-face edge of described groove is higher than the position of described argentum powder precipitation and lower than liquid level；When the liquid level in described reactor is lower than the upper end-face edge of the groove of described baffle plate, repeat aforementioned process 1., 2., 3. 7 times；Finally adding the glass dust that granularity is 2um of 0.15 weight portion, stir post-drying, obtains finished product.
Comparative example 4～6
In the cleaning process of argentum powder, except when when described siphon draws water close to the position that argentum powder precipitates, not placing outside a plate washer with groove at described siphon tube inlet place, other conditions are respectively with embodiment 1～3.Prepare argentum powder 4, argentum powder 5 and argentum powder 6 respectively.
Detect the argent content in the finished product in embodiment 1～6 respectively, then the loss rate of the productivity of argent and argent in Statistics Implementation example 1～6, refer to table 1.
Table 1
From embodiment 1～3, choose appropriate argentum powder 1, argentum powder 2 and argentum powder 3 more respectively carry out quantitative measurement, refer to table 2.
Table 2
Can being drawn by table 1, adopt technique provided by the present invention to produce argentum powder, compared with prior art, the loss amount of silver is much smaller, and this improves the conversion ratio of silver, is greatly saved the production cost of enterprise.
Can being drawn by table 2, adopting technique provided by the present invention to produce argentum powder, the requirement of its granularity complies fully with the instructions for use of conductive material.
The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all within the spirit and principles in the present invention, any amendment of making, equivalent replacement, improvement etc., should be included within protection scope of the present invention.
Claims (7)
1. one kind adopts the technique that liquid phase reduction produces argentum powder, it is characterised in that the method comprises the steps:
A, silver salt solution preparation: being dissolved in deionized water by silver nitrate, prepared concentration is the silver nitrate solution of 0.5～1.5mol/L, then inserts in reactor stand-by by described silver nitrate solution；
B, argentum powder preparation: described silver nitrate solution is heated to 35～40 DEG C, is subsequently adding alkaline substance solution；Then continue to heat described silver nitrate solution to 47～53 DEG C, add dispersant；Continue again heating described silver nitrate solution to 58～61 DEG C, add reducing agent；Until the chemical reaction in described silver nitrate solution is complete, obtain argentum powder just finished product；
C, argentum powder cleaning: in described reactor, 1., first add deionized water, described argentum powder just finished product washed, then stands；2., after the argentum powder in described reactor is precipitated to lower floor, recycle siphon principle, extract the supernatant in described reactor with siphon；3., when described siphon draws water close to the position that argentum powder precipitates, a plate washer with groove is placed at described siphon tube inlet place；Upward, described siphonal entrance is placed in the groove of described baffle plate the groove of described baffle plate；The upper end-face edge of described groove is higher than the position of described argentum powder precipitation and lower than liquid level；When the liquid level in described reactor is lower than the upper end-face edge of the groove of described baffle plate, repeat aforementioned process 1., 2., 3. 5～7 times；Finally dry, obtain argentum powder finished product.
2. the technique that employing liquid phase reduction according to claim 1 produces argentum powder, it is characterised in that: in described step b, described alkaline substance solution is concentration is 5～6.5mol/L sodium hydroxide solution；When adding sodium hydroxide solution, the temperature of described silver nitrate solution is 37 DEG C；The volume ratio of described sodium hydroxide solution and described silver nitrate solution is 18～22:100.
3. the technique that employing liquid phase reduction according to claim 1 produces argentum powder, it is characterized in that: in described step b, described dispersant is one or more the mixture in polyvinylpyrrolidone, gelatin, monoethanolamine, diethanolamine and triethanolamine.
4. the technique that employing liquid phase reduction according to claim 3 produces argentum powder: in described step b, during the described gelatin of addition, the temperature of described silver nitrate solution is 50 DEG C；The ratio of the quality of described gelatin and the volume of described silver nitrate solution is 0.8～1g/1L.
5. the technique that employing liquid phase reduction according to claim 1 produces argentum powder, it is characterized in that: in described step b, described reducing agent is the one in aluminum, ferrum, zinc, copper, formic acid, formates, hydrazine hydrate, aldehydes, amine, alcohols, glucose, fatty acid or ascorbic acid.
6. the technique that employing liquid phase reduction according to claim 5 produces argentum powder, it is characterised in that: in described step b, when adding described hydrazine hydrate, the temperature of described silver nitrate solution is 60 DEG C；The volume ratio of described hydrazine hydrate and described silver nitrate solution is 2～4/100.
7. the technique that employing liquid phase reduction according to claim 1 produces argentum powder, it is characterised in that: in described step c, the argentum powder after described cleaning before baking, is also added into the glass dust that granularity is 1～2um；The mass ratio of the silver nitrate being dissolved in deionized water in the glass dust of described addition and described step a is 0.3～0.6:100.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106735290A (en) * | 2016-11-30 | 2017-05-31 | 华南理工大学 | Nano Silver prepared by a kind of utilization reducing sugar low-temperature reduction and preparation method thereof and the application in electrically conductive ink |
| CN115464147A (en) * | 2022-09-16 | 2022-12-13 | 北京曙光航空电气有限责任公司 | Silver powder manufacturing method |
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| CN104308176A (en) * | 2014-10-11 | 2015-01-28 | 中国振华集团云科电子有限公司 | Cleaning process of silver powder for producing conductive material |
| CN104325151A (en) * | 2014-10-11 | 2015-02-04 | 中国振华集团云科电子有限公司 | Silver powder preparing method |
| CN104475755A (en) * | 2014-12-30 | 2015-04-01 | 山西森达源科技有限公司 | Preparation method of spheroidal ultrafine silver powder for front surface of solar cell |
| CN105506277A (en) * | 2014-09-22 | 2016-04-20 | 湖北鑫荣矿业有限公司 | Silver separation method through nitric acid |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPS4842782B1 (en) * | 1969-03-13 | 1973-12-14 | ||
| CN103350235A (en) * | 2013-07-16 | 2013-10-16 | 宁波晶鑫电子材料有限公司 | Method for preparing high-brightness silver powder for contact adhesion |
| CN105506277A (en) * | 2014-09-22 | 2016-04-20 | 湖北鑫荣矿业有限公司 | Silver separation method through nitric acid |
| CN104308176A (en) * | 2014-10-11 | 2015-01-28 | 中国振华集团云科电子有限公司 | Cleaning process of silver powder for producing conductive material |
| CN104325151A (en) * | 2014-10-11 | 2015-02-04 | 中国振华集团云科电子有限公司 | Silver powder preparing method |
| CN104475755A (en) * | 2014-12-30 | 2015-04-01 | 山西森达源科技有限公司 | Preparation method of spheroidal ultrafine silver powder for front surface of solar cell |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106735290A (en) * | 2016-11-30 | 2017-05-31 | 华南理工大学 | Nano Silver prepared by a kind of utilization reducing sugar low-temperature reduction and preparation method thereof and the application in electrically conductive ink |
| CN115464147A (en) * | 2022-09-16 | 2022-12-13 | 北京曙光航空电气有限责任公司 | Silver powder manufacturing method |
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Application publication date: 20160629 |