CN102380618A - Method for preparing nano-tungsten powder by using sulfuric acid precipitation-H2 breathable reduction process - Google Patents
Method for preparing nano-tungsten powder by using sulfuric acid precipitation-H2 breathable reduction process Download PDFInfo
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- CN102380618A CN102380618A CN2011103559220A CN201110355922A CN102380618A CN 102380618 A CN102380618 A CN 102380618A CN 2011103559220 A CN2011103559220 A CN 2011103559220A CN 201110355922 A CN201110355922 A CN 201110355922A CN 102380618 A CN102380618 A CN 102380618A
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Abstract
The invention belongs to the technical field of preparation of metal powder which belongs to a metal material, in particular to a method for preparing nano-tungsten powder by using a sulfuric acid precipitation-H2 breathable reduction process, which is suitable for large-scale industrial production of nano-tungsten powder. The method is characterized by comprising: performing a precipitation reaction under the common action of a separant and a dispersing agent by using diluted solution of ammonium tungstate and diluted aqueous solution of sulfuric acid to obtain nano particular tungstic acid precipitate, performing centrifugal separation at high speed, washing repeatedly, drying under vacuum, reducing in a continuous breathable H2 reduction furnace, and finally obtaining nano tungsten powder with an average particle size of less than or equal to 35 nano meters. The method has the advantages that: the cost is low; the production efficiency is high; the equipment is simple; the process is short; the investment is small; and continuous and automatic large-scale production can be realized easily.
Description
Technical field
The invention belongs to metal dust preparing technical field in the metal material, particularly provide a kind of with sulfuric acid precipitation-H
2Ventilative reducing process prepares the method for nano grade tungsten powder, is applicable to the large-scale industrial production of nano grade tungsten powder.
Background technology
Metal tungsten powder is used to prepare high-melting-point pure tungsten goods widely, like rocket nozzle, and the heavy armor armor-piercing bullet, tungsten filament, tungsten bar, tungsten plate, the tungsten paper tinsel, and the heat-resisting part of various superhigh temperature etc.Tungsten and a certain amount of iron, nickel, silver, metals such as copper can be made into the high-density alloy of multiple series, boundling bullet part, the CPU heat pillow material of computer, the encapsulating material of transistor, airplane tail group weight material automatic watch pendulum, high-performance electrical contact material etc.Because tungsten all has good protective capacities to multiple radiation, is widely applied to again in the fusion reactor material in recent years.Since nineteen twenty-three, because the develop rapidly of carbide alloy industry, almost there has been 2/3 tungsten powder to be used to process the WC powder; To satisfy the needs that the world produces about more than 80,000 tons of carbide alloy per year, in recent years, along with above-mentioned industrial expansion; Particularly the requirement of nano grade tungsten powder is more urgent to ultra-fine grain, and each industrial power of the world has dropped into a large amount of manpower and materials over more than 20 year; Nearly hundred patents of invention have appearred in the production technology of developmental research nano grade tungsten powder.China is the research of key research project such as existing country 863,973 and national natural fund over nearly 20 years, has obtained multinomial patent of invention.
The production technology of the tungsten powder that nearly 40 years patented technology and manufacturer are used is divided three classes substantially, and 1. wet method (alkaline process) is carried tungsten: filtration, roasting, H
2Reducing process.2. wet method (acid system) is carried tungsten: filtration, roasting, H
2Reducing process.These two class methods are mainly produced the typical process of tungsten powder by ore; Its characteristics mainly are the tungsten powders of middle fine grained (0.5～8 micron) of can be mass-produced; Shortcoming is because the filter cloth landing net hole of using is too thick in producing; Cause ammonium tungstate or tungstic acid particle too thick, so can not produce≤0.3 micron ultra-fine or nano level tungsten powder.3. ammonium tungstate tungstic acid reducing process, the method is actually the back segment operation of preceding two kinds of methods, and its raw material remains with the middle fine grained ammonium tungstate of the first two type technology gained or anhydrous wolframic acid powder through H
2The technology of tungsten powder is produced in reduction, so still can not produce nano grade tungsten powder.
Summary of the invention
The present invention seeks to solve deposition, separation difficulty and the WO of nano particle
3Nano particle in reduction process steam to the nano-tungsten powder particle unmanageable difficult problem of phenomenon of growing up.Be reflected at strong acid and ammonium tungstate and can generate nanoscale wolframic acid solids precipitation thing in the aqueous solution, separate the nanoparticle precipitate thing that takes out wolframic acid through Sharples centrifuge, again after vacuum drying with continuous ventilated forced drainage type H
2The reduction furnace low-temperature reduction is prepared the nano-tungsten powder of average grain diameter≤35nm.
A kind of with sulfuric acid precipitation-H
2Ventilative reducing process prepares the method for nano-tungsten powder; It is characterized in that: adopt a kind of ammonium tungstate weak solution and dilute sulfuric acid aqueous solution under interleaving agent and dispersant acting in conjunction, to carry out precipitation reaction; Generate Nanoparticulate wolframic acid sediment, separate, clean repeatedly through high speed centrifugation; Vacuum drying, permeability type H continuously
2Reduction furnace reduces, and finally is prepared into the nano-tungsten powder of average grain diameter≤35nm.The purpose that in ammonium tungstate aqueous solution, adds interleaving agent and dispersant in advance is in order to make wolframic acid (H
2WO
4) the nanoscale precipitation particles can not assemble and grow up.
Concrete processing step is:
1) preparation ammonium tungstate weak solution (A):
With concentration is that 30% ammonium tungstate solution 387.6ml. joins in the distilled water of 612.4ml, constantly stirs and processes the ammonium tungstate dilute solution (A) that concentration is 0.5mol/L; Concentration is that 30% ammonium tungstate solution contains WO
3Mass fraction proportion be 1.29mol/L;
2) preparation interleaving agent and dispersant solution (B), i.e. PVA and SDS solution (B):
Press PVA:H
2O=2:100; SDS:H
2The mass ratio of O=2:100, weighing PVA and SDS join in the distilled water simultaneously respectively, 80～100 ℃ of heating, constantly stir until dissolving fully and process solution (B);
3) preparation contains the ammonium tungstate weak solution (C) of interleaving agent and dispersant:
Press ammonium tungstate weak solution volume ratio A:B=4:1 with A, two kinds of solution of B mix the powerful 30～60min of stirring and process solution (C);
4) add the acid deposition:
With concentration is the dilution heat of sulfuric acid of 0.5mol/L; By volume, solution (C): dilute sulfuric acid=1:1 is constantly joining dilution heat of sulfuric acid in the solution (C) under powerful the stirring; Left standstill 2～4 hours after continue stirring 1～1.5h, obtain containing and sedimentaryly react to such an extent that mother liquor is sent to centrifugation;
5) the wolframic acid sediment of high speed centrifugation separating nano-particles shape.
In the Sharples centrifuge of ZL 200410088759.6 record, waste reaction solution separated with precipitate particles and extract residual waste liquid then out; In centrifuge, add the distilled water stirring and washing repeatedly, sediment centrifugalizes and extracts out waste liquid again, and the sulfate radical particle in the sediment washes; Clean with dehydration of alcohol for the last time, press mass ratio, sediment: industrial alcohol=1:5, stir and processed turbid solution in 30 minutes, through centrifugation, remove residual water and recovered alcohol in the sediment again;
6) vacuum drying
With sediment mud after the centrifugal dehydration or wet-milling piece, put into vacuum drying chamber, dry 1～2h under 20～30pa, 60～90 ℃ of conditions; Dried powder is crossed 150 eye mesh screens, to remove the appearance foreign material, promptly processes the WO3 precursor powder of nano level superfine.
7) permeability type H2 reduction prepares nano-tungsten powder continuously:
(WO3) precursor powder after the above-mentioned vacuum drying is put into the permeability type boat; In the continuous permeability type H2 reduction furnace of ZL200520023268.3 record, once be reduced into the nano-tungsten powder that average grain diameter is 35nm; Reducing condition: 650～750 ℃ of temperature; Time 40～65min, H2 gas cross section flow 50～80ml/cm2.min;
8) Performance Detection of nano-tungsten powder
Performance Detection to nano-tungsten powder is mainly carried out XRD, FSEM (field emission scanning electron microscope) and BET (specific surface), and SAXS, (international new standard nano powder granularity and granularmetric composition detection method) measured;
9) packing of nano-tungsten powder
The packing of nano-tungsten powder must adopt vacuum double aluminium plastic bag packing, and skin also should use metal shell protection container.In the daily use, used operation should be carried out in the vacuumizing case.
Said interleaving agent is that PVA is a polyvinyl alcohol, and dispersant is that SDS is a lauryl sodium sulfate.
Said dilute sulfuric acid aqueous solution can use rare nitric acid or watery hydrochloric acid to substitute.
Advantage of the present invention
(1) providing a kind of from production technology can change fast continuously on a large scale, the new technology of the metal tungsten powder of (average grain diameter is 35nm) of production nano level superfine.
(2) device therefor is simple, and operation is short, and small investment is prone to realize serialization automation control, has improved the automated production level of China's nano-tungsten powder greatly.
(3) adopt the centrifugal Technology of Auto Separation of continuous high-speed to replace ancient traditional cloth bag filtering technique; Not only improved the utilization ratio of tungsten ore resource; The more important thing is the deposition production efficiency that has improved nano particle, make the suitability for industrialized production of nanometer powder become possibility.
(4) adopt continuous ventilated forced drainage type H
2Reduction furnace has fundamentally solved in the tungsten powder reduction process, remain in the material steam to tungsten powder particles grow up the effect a unmanageable difficult problem, so from equipment, can guarantee normal, the stable production of nano-tungsten powder.
(5) nano-tungsten powder of producing is subsphaeroidal, epigranular, narrow particle size distribution, good dispersion.
(6) the simple small investment of device therefor is prone to start, and suitable medium-sized and small enterprises are produced fast.
Description of drawings
Fig. 1 is a process chart of the present invention.
The specific embodiment
Embodiment 1: the nano-tungsten powder of preparation 1kg should follow these steps to accomplish.
1. prepare A solution: weighing 30% (contains WO
3Mass fraction) ammonium tungstate solution 4204g, add distilled water 6680g, constantly stir and process rare ammonium tungstate solution (A) 10.88kg that concentration is 0.5mol/L.
2. prepare B solution: weighing PVA powder and each 21.8g of SDS powder join in the distilled water of 1047g simultaneously, process isolation-dispersant solution that concentration is 4% (quality) (B) 1090.6g.
3. preparation C solution: A, two kinds of solution of B are pressed A:B=10:1 (volume ratio) the A solution of 10.88 kg is mixed with the B solution of 1.09kg, be mixed with solution (C) 11.99kg that contains isolation-dispersant (0.336% mass concentration).
4. add the acid deposition: preparation dilution heat of sulfuric acid: the concentrated sulfuric acid is slowly joined the dilution heat of sulfuric acid 11.99kg that is mixed with 0.5mol/L in the distilled water.Press C solution: dilute sulfuric acid=1:1 (volume ratio) then, constantly powerful stir down dilution heat of sulfuric acid to be joined continue stirring in the C solution and left standstill 3 hours after 1 hour, then reactant liquor continuously is injected in the continuous centrifugal separator with acid-proof pump.
5. high speed centrifugation separating nano-particles shape wolframic acid sediment
In the centrifuge of 10L volume, continuously the wolframic acid sediment in the reaction solution is separated with waste liquid, inject distilled water after getting rid of waste liquid, in centrifuge, constantly stir, the washing and precipitating thing; Start centrifuge again and get rid of the cleaning waste liquid; 6 times so repeatedly, add the 8L industrial alcohol then, centrifugation again after the stirring and washing; Get rid of recovered alcohol, take out muddy or wet-milling lumpy nanometer wolframic acid sediment.
6. vacuum drying
With sediment mud after the centrifugal dehydration or wet-milling piece, put into vacuum drying chamber, at (20～30pa, 60～90 ℃) down dry (1～2h) and recovered alcohol.Dried powder is crossed (150 order) screen cloth, to remove external foreign material.Can be made into the WO of nano level superfine
3Precursor powder.
7. continuous permeability type H
2Reduction preparation nano-tungsten powder.
With (the WO after the above-mentioned vacuum drying
3) precursor powder puts into the permeability type boat, at permeability type H continuously
2In the reduction furnace (patent of invention ZL200520023268.3) 650～750 ℃, 40～65min, H2 gas cross section flow (50～80ml/cm
2.min) under the condition, once be reduced into the nano-tungsten powder that average grain diameter is 35nm.
8. the Performance Detection of nano-tungsten powder.
Performance Detection to nano-tungsten powder is mainly carried out the XRD material phase analysis, FSEM (field emission scanning electron microscope) and BET (specific surface), and SAXS, (international new standard nano powder granularity and granularmetric composition detection method) measured.
9. product is vacuum-packed.
Embodiment 2: the nano-tungsten powder of preparation 5kg should follow these steps to accomplish.
1. prepare A solution: weighing 30% (contains WO
3Mass fraction) ammonium tungstate solution 21020g, add distilled water 33400g, constantly stir and process rare ammonium tungstate solution (A) 54.42kg that concentration is 0.5mol/L.
2. prepare B solution: weighing PVA powder and each 109g of SDS powder join in the distilled water of 5235g simultaneously, process isolation-dispersant solution that concentration is 4% (quality) (B) 5344g.
3. preparation C solution: A, two kinds of solution of B are pressed A:B=10:1 (volume ratio) the A solution of 54.40 kg is mixed with the B solution of 1.09kg, be mixed with solution (C) 59.95kg that contains isolation-dispersant (0.336% mass concentration).
4. add the acid deposition: preparation dilution heat of sulfuric acid: the concentrated sulfuric acid is slowly joined the dilution heat of sulfuric acid 59.95kg that is mixed with 0.5mol/L in the distilled water.Press C solution: dilute sulfuric acid=1:1 (volume ratio) then, constantly powerful stir down sulfuric acid solution to be joined continue stirring in the C solution and left standstill 3 hours after 1 hour, then reactant liquor continuously is injected in the continuous centrifugal separator with acid-proof pump.
5. high speed centrifugation separating nano-particles shape wolframic acid sediment
In the centrifuge of 10L volume, continuously the wolframic acid sediment in the reaction solution is separated with waste liquid, inject distilled water after getting rid of waste liquid, in centrifuge, constantly stir, the washing and precipitating thing; Start centrifuge again and get rid of the cleaning waste liquid; 6 times so repeatedly, add the 8L industrial alcohol then, centrifugation again after the stirring and washing; Get rid of recovered alcohol, take out muddy or wet-milling lumpy nanometer wolframic acid sediment.
6. vacuum drying
With sediment mud after the centrifugal dehydration or wet-milling piece, put into vacuum drying chamber, at (20～30pa, 60～90 ℃) down dry (1～2h) and recovered alcohol.Dried powder is crossed (150 order) screen cloth, to remove external foreign material.Can be made into the WO of nano level superfine
3Precursor powder.
7. continuous permeability type H
2Reduction preparation nano-tungsten powder.
With (the WO after the above-mentioned vacuum drying
3) precursor powder puts into the permeability type boat, at permeability type H continuously
2In the reduction furnace (patent of invention ZL200520023268.3) 650～750 ℃, 40～65min, H
2Gas cross section flow (under 50～80ml/cm2.min) conditions, once is reduced into the nano-tungsten powder that average grain diameter is 35nm.
8. the Performance Detection of nano-tungsten powder
Performance Detection to nano-tungsten powder is mainly carried out the XRD material phase analysis, FSEM (field emission scanning electron microscope) and BET (specific surface), and SAXS, (international new standard nano powder granularity and granularmetric composition detection method) measured.
9. product is vacuum-packed.
Claims (2)
1. one kind with sulfuric acid precipitation-H
2Ventilative reducing process prepares the method for nano-tungsten powder; It is characterized in that: adopt a kind of ammonium tungstate weak solution and dilute sulfuric acid aqueous solution under interleaving agent and dispersant acting in conjunction, to carry out precipitation reaction; Generate Nanoparticulate wolframic acid sediment, separate, clean repeatedly through high speed centrifugation; Vacuum drying, permeability type H continuously
2Reduction furnace reduces, and finally is prepared into the nano-tungsten powder of average grain diameter≤35nm; Concrete processing step is:
1) preparation ammonium tungstate weak solution (A):
With concentration is that 30% ammonium tungstate solution 387.6ml. joins in the distilled water of 612.4ml, constantly stirs and processes the ammonium tungstate dilute solution (A) that concentration is 0.5mol/L; Concentration is that 30% ammonium tungstate solution contains WO
3Mass fraction proportion be 1.29mol/L;
2) preparation interleaving agent and dispersant solution (B), said interleaving agent is that PVA is a polyvinyl alcohol, dispersant is that SDS is a lauryl sodium sulfate;
Press PVA:H
2O=2:100; SDS:H
2The mass ratio of O=2:100, weighing PVA and SDS join in the distilled water simultaneously respectively, 80～100 ℃ of heating, constantly stir until dissolving fully and process solution (B);
3) preparation contains the ammonium tungstate weak solution (C) of interleaving agent and dispersant:
Press ammonium tungstate weak solution volume ratio A:B=4:1 with A, two kinds of solution of B mix the powerful 30～60min of stirring and process solution (C);
4) add the acid deposition:
With concentration is the dilution heat of sulfuric acid of 0.5mol/L; By volume, solution (C): dilute sulfuric acid=1:1 is constantly joining dilution heat of sulfuric acid in the solution (C) under powerful the stirring; Left standstill 2～4 hours after continue stirring 1～1.5h, obtain containing and sedimentaryly react to such an extent that mother liquor is sent to centrifugation;
5) the wolframic acid sediment of high speed centrifugation separating nano-particles shape:
In the Sharples centrifuge of ZL 200410088759.6 record, waste reaction solution separated with precipitate particles and extract residual waste liquid then out; In centrifuge, add the distilled water stirring and washing repeatedly, sediment centrifugalizes and extracts out waste liquid again, and the sulfate radical particle in the sediment washes; Clean with dehydration of alcohol for the last time, press mass ratio, sediment: industrial alcohol=1:5, stir and processed turbid solution in 30 minutes, through centrifugation, remove residual water and recovered alcohol in the sediment again;
6) vacuum drying
With sediment mud after the centrifugal dehydration or wet-milling piece, put into vacuum drying chamber, dry 1～2h under 20～30pa, 60～90 ℃ of conditions; Dried powder is crossed 150 eye mesh screens, to remove the appearance foreign material, promptly processes the WO3 precursor powder of nano level superfine;
7) permeability type H2 reduction prepares nano-tungsten powder continuously:
(WO3) precursor powder after the above-mentioned vacuum drying is put into the permeability type boat; In the continuous permeability type H2 reduction furnace of ZL200520023268.3 record, once be reduced into the nano-tungsten powder that average grain diameter is 35nm; Reducing condition: 650～750 ℃ of temperature; Time 40～65min, H2 gas cross section flow 50～80ml/cm2.min;
8) Performance Detection of nano-tungsten powder
Performance Detection to nano-tungsten powder is mainly carried out XRD, FSEM (field emission scanning electron microscope) and BET (specific surface), and SAXS, (international new standard nano powder granularity and granularmetric composition detection method) measured;
9) packing of nano-tungsten powder
The packing of nano-tungsten powder must adopt vacuum double aluminium plastic bag packing, and skin also should use metal shell protection container.
2. a kind of according to claim 1 with sulfuric acid precipitation-H
2Ventilative reducing process prepares the method for nano-tungsten powder, it is characterized in that: said dilute sulfuric acid aqueous solution can substitute with rare nitric acid or watery hydrochloric acid.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103231073A (en) * | 2013-04-27 | 2013-08-07 | 北京科技大学 | Tungsten nanowire material and manufacture method thereof |
| CN103302300A (en) * | 2013-06-24 | 2013-09-18 | 刘亚静 | Preparation method of tungsten nano powder |
| CN106583744A (en) * | 2017-01-21 | 2017-04-26 | 杨林 | Preparation method of noble metal nanoparticles |
| CN106623962A (en) * | 2016-12-31 | 2017-05-10 | 湖南省华京粉体材料有限公司 | Method for preparing nanometer tungsten powder by organizing sodium tungstate |
| CN111644633A (en) * | 2020-05-15 | 2020-09-11 | 北京化工大学 | Supergravity preparation method of nano tungsten powder |
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| CN103231073A (en) * | 2013-04-27 | 2013-08-07 | 北京科技大学 | Tungsten nanowire material and manufacture method thereof |
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| CN106583744A (en) * | 2017-01-21 | 2017-04-26 | 杨林 | Preparation method of noble metal nanoparticles |
| CN106583744B (en) * | 2017-01-21 | 2018-06-19 | 杨林 | It is a kind of to prepare noble metal nano particles method |
| CN111644633A (en) * | 2020-05-15 | 2020-09-11 | 北京化工大学 | Supergravity preparation method of nano tungsten powder |
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