CN112045198A - System and method for preparing uniform ultra-coarse tungsten powder - Google Patents
System and method for preparing uniform ultra-coarse tungsten powder Download PDFInfo
- Publication number
- CN112045198A CN112045198A CN202010878334.4A CN202010878334A CN112045198A CN 112045198 A CN112045198 A CN 112045198A CN 202010878334 A CN202010878334 A CN 202010878334A CN 112045198 A CN112045198 A CN 112045198A
- Authority
- CN
- China
- Prior art keywords
- doping
- tungsten oxide
- coarse
- spray drying
- inlet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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
- B22F9/20—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds
- B22F9/22—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds using gaseous reductors
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
The invention discloses a system and a method for preparing uniform ultra-coarse tungsten powder, wherein the system for preparing the uniform ultra-coarse tungsten powder comprises a doping unit and a reduction unit, and the doping unit comprises a stirring device, a spray drying tower, a heating device and a screening device. The spray drying tower is respectively connected with the stirring device, the heating device and the screening device, and the screening device is connected with the reduction unit. The aim of uniform doping is achieved by carrying out liquid-solid doping in the stirring device. The material is discharged from the bottom of the stirring device and directly enters the spray drying tower for drying, so that the doping-drying is integrally completed, the labor intensity is greatly reduced, and the production efficiency is improved. And finally, supplying the sieved doped tungsten oxide powder into a reduction unit to be in contact with hydrogen for reduction, thereby obtaining the ultra-coarse tungsten powder with high purity and uniform particle size distribution.
Description
Technical Field
The invention belongs to the technical field of powder metallurgy, and particularly relates to a system and a method for preparing uniform ultra-coarse tungsten powder.
Background
With the continuous expansion of the application field of hard alloy, the fact that tungsten carbide is used as the main raw material for producing hard alloy and the development of part of tungsten carbide to extra-coarse particles is not contended. The coarse tungsten carbide has the advantages of few microstructure defects, high microhardness, few microstrain and the like, so the coarse tungsten carbide is widely applied to the aspects of mine tools, metal rolling rails, engineering machinery, stamping dies, hard surface technology and the like. The coarse tungsten powder is a raw material for producing coarse tungsten carbide, most manufacturers produce the coarse metal tungsten powder by doping an alkali metal solution into the raw material for preparing the tungsten powder for catalyzing growth, the tungsten powder has incomplete crystallization and poor doping uniformity, so that more abnormally-grown particles exist in the tungsten powder, the tungsten powder has poor integral uniformity, and incomplete carbonization easily occurs in the subsequent carbonization process, so that the product quality is influenced.
Therefore, the existing preparation method of ultra-coarse tungsten powder is to be improved.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, an object of the present invention is to provide a system and a method for preparing tungsten powder with uniform ultra-coarse particles, which can improve the uniformity of tungsten oxide doping and prevent the powder from growing abnormally during the reduction of tungsten oxide, thereby improving the uniformity of tungsten powder, improving the product quality, and simultaneously greatly reducing the labor intensity and improving the production efficiency.
In a first aspect of the present invention, a system for producing uniform ultra-coarse tungsten powder is provided. According to an embodiment of the present invention, the system for preparing uniform ultra-coarse tungsten powder comprises:
a doping unit, the doping unit comprising:
the stirring device is internally provided with a stirring assembly, the stirring device is provided with a water inlet, a doping agent inlet, a tungsten oxide inlet and a doping liquid outlet, and the doping liquid outlet is provided with a first discharge valve;
the spray drying tower is provided with a doped liquid inlet, an air outlet and a doped dried tungsten oxide outlet, the doped liquid inlet is connected with the doped liquid outlet, the outlet section of the doped liquid inlet is provided with a rotatable centrifugal atomizing disc, and the discharge port is provided with a second discharge valve;
the heating equipment is connected with the air inlet;
the screening device is connected with the doped dried tungsten oxide outlet;
the reduction unit is provided with a hydrogen inlet, a doped dry tungsten oxide inlet and an ultra-coarse tungsten particle tungsten powder outlet, and the doped dry tungsten oxide inlet is connected with a screen underflow outlet of the screening device.
According to the system for preparing the uniform ultra-coarse tungsten powder, provided by the embodiment of the invention, the tungsten oxide, the water and the dopant are stirred and mixed in the stirring device by using the stirring component, namely, a liquid-solid doping mode is adopted, so that the doping uniformity can be ensured, the doping amount can be accurately controlled, and the uniformity of tungsten powder particles is improved. Then the blower, the exhaust fan and the heating device are sequentially started, hot air is supplied into the spray drying tower from the air inlet to preheat the spray drying tower, when the temperature is heated to the preset temperature, the centrifugal atomizing disk on the spray drying tower is started, the rotating speed of the centrifugal atomizing disk is set, then opening a first discharge valve, a second discharge valve and a screening device, controlling the feeding speed, sending the doping liquid to a centrifugal atomizing disc at the top of the spray drying tower from a doping liquid outlet at the bottom of the stirring device, and is dispersed into extremely small fog-like liquid drops, the surface area of the doping liquid is greatly increased after the doping liquid is atomized, the fog-like liquid drops are fully contacted with hot air, can complete instant drying, the obtained powdery doped tungsten oxide falls to the bottom of the spray drying tower and is sent to a screening device from a doped dried tungsten oxide outlet, and sieving to remove abnormal coarse particles, and exhausting waste gas generated in the drying process from an exhaust port by using an exhaust fan. The material is discharged from the bottom of the stirring device and directly enters the spray drying tower for drying, so that the doping-drying is integrally completed, the labor intensity is greatly reduced, and the production efficiency is improved. And finally, supplying the sieved doped tungsten oxide powder into a reduction unit to be in contact with hydrogen for reduction, so that ultra-coarse tungsten powder with high purity and uniform particle size distribution can be obtained, and the preparation of coarse-particle tungsten carbide with few microstructure defects is possible.
In addition, the system for preparing uniform ultra-coarse tungsten powder according to the above embodiment of the present invention may also have the following additional technical features:
in some embodiments of the invention, a stirrer is arranged at the bottom of the stirring device. Therefore, tungsten oxide powder can be prevented from sinking, and the doping uniformity is improved.
In some embodiments of the invention, the stirring device is located above the spray drying tower in the height direction. Therefore, the doping-drying can be integrally completed, the labor intensity is greatly reduced, and the production efficiency is improved.
In some embodiments of the invention, the spray drying tower is provided with a viewing window in a side wall thereof. Thereby, the feeding speed of the dope in the spray drying tower is conveniently observed and controlled.
In some embodiments of the invention, the dope inlet is provided at a central position of the top of the spray drying tower. Therefore, on one hand, the wall sticking phenomenon can be avoided, and on the other hand, the doped liquid fog drops can be heated uniformly when descending, so that the product quality is improved.
In some embodiments of the invention, the air inlet is located above the air outlet in the height direction. This makes it possible to evaporate the water in the dope instantaneously and dry the dope into powder in an extremely short time.
In some embodiments of the invention, the heating device is an air heating device. Thus, hot air can be supplied into the spray drying tower to instantaneously evaporate the moisture in the dope solution, and the dope solution can be dried into doped tungsten oxide powder in an extremely short time.
In some embodiments of the invention, the spray drying tower is located above the screening device in the height direction. Therefore, after being instantly dried into powder in the spray drying tower, the vaporific liquid drops of the doping liquid can directly fall to the screening device through the doped drying tungsten oxide outlet at the bottom of the spray drying tower, so that the drying and screening can be completed integrally, the drying process and the screening process can be carried out simultaneously, the labor intensity is greatly reduced, and the production efficiency is improved.
In some embodiments of the invention, the screening device is a vibrating screen. Thus, the abnormally coarse particles can be removed, and the doped tungsten oxide powder having a uniform particle size can be obtained.
In a second aspect of the present invention, the present invention provides a method for preparing ultra-coarse tungsten powder using the above system. According to an embodiment of the invention, the method comprises:
(1) feeding tungsten oxide, water and a doping agent into the stirring device for stirring, feeding the obtained doping liquid into the spray drying tower, drying the doping liquid under the action of hot air supplied by the heating equipment, and screening the obtained doped dried tungsten oxide by the screening device;
(2) and feeding the undersize obtained by the screening device to the reduction unit to be in contact with hydrogen for reduction so as to obtain ultra-coarse tungsten powder.
According to the method for preparing the ultra-coarse tungsten powder by using the system, the tungsten oxide, the water and the dopant are stirred and mixed in the stirring device by using the stirring assembly, namely, a liquid-solid doping mode is adopted, so that the doping uniformity can be ensured, the doping amount can be accurately controlled, and the uniformity of tungsten powder particles is improved. Then opening a blower, an exhaust fan and heating equipment in sequence, supplying hot air into the spray drying tower from an air inlet to preheat the spray drying tower, when the spray drying tower is heated to a preset temperature, opening a centrifugal atomizing disc on the spray drying tower, setting the rotating speed of the centrifugal atomizing disc, opening a first discharge valve, a second discharge valve and a screening device after doping liquid in a stirring device is uniformly mixed, controlling the feeding speed, sending the doping liquid to the centrifugal atomizing disc at the top of the spray drying tower from a doping liquid outlet at the bottom of the stirring device and dispersing the doping liquid into tiny fog-shaped liquid drops, greatly increasing the surface area of the atomized doping liquid drops, fully contacting the fog-shaped liquid drops with the hot air, completing instant drying, dropping the obtained powdery doped tungsten oxide to the bottom of the spray drying tower, sending the doped dried tungsten oxide to the screening device from a doped tungsten oxide outlet, and screening the obtained powder, removing abnormal coarse particles, and exhausting the waste gas generated in the drying process from an exhaust port by using an exhaust fan. The material is discharged from the bottom of the stirring device and directly enters the spray drying tower for drying, so that the doping-drying is integrally completed, the labor intensity is greatly reduced, and the production efficiency is improved. And finally, supplying the sieved doped tungsten oxide powder into a reduction unit to be in contact with hydrogen for reduction, so that ultra-coarse tungsten powder with high purity and uniform particle size distribution can be obtained, and the preparation of coarse-particle tungsten carbide with few microstructure defects is possible.
In addition, the method for preparing ultra-coarse tungsten powder by using the system according to the above embodiment of the present invention may further have the following additional technical features:
in some embodiments of the invention, in the step (1), the tungsten oxide has a particle size of 20-80 μm, so that uniformity and sufficiency of doping are ensured, and ultra-coarse tungsten powder with uniform particle size is obtained.
In some embodiments of the present invention, in the step (1), the dopant is an alkali metal salt, and a mass ratio of the tungsten oxide, the water, and the dopant is (1000 to 10000): (500-5000): (0.5 to 100). Therefore, on one hand, the fluidity of the doping liquid and the uniformity and sufficiency of doping can be ensured, on the other hand, the doping liquid fog drops can be ensured to be instantly and fully dried in the spray drying tower, and the obtained tungsten oxide powder after doping has good dispersibility. .
In some embodiments of the present invention, in the step (1), the temperature of the hot gas supplied by the heating device is 90 to 150 ℃. Therefore, the doped liquid fog drops can be ensured to be instantly and fully dried in the spray drying tower, and the obtained doped tungsten oxide powder has good dispersibility.
In some embodiments of the invention, in the step (2), the temperature of the reduction is 980-1150 ℃, the time is 4-10 h, and the hydrogen flow is 14-20 m3/h。Therefore, the method is beneficial to obtaining the ultra-coarse tungsten powder with uniform granularity.
In some embodiments of the present invention, in the step (2), the ultra-coarse tungsten powder has a particle size of 20 to 100 μm.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic diagram of a system for producing uniform ultra-coarse tungsten powder according to one embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a system for preparing uniform ultra-coarse tungsten powder according to still another embodiment of the present invention;
FIG. 3 is a schematic structural diagram of a system for preparing uniform ultra-coarse tungsten powder according to yet another embodiment of the present invention;
fig. 4 is a schematic flow chart of a method for preparing ultra-coarse tungsten powder by using the system according to an embodiment of the invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In one aspect of the invention, a system for producing uniform ultra-coarse tungsten powder is provided. According to an embodiment of the present invention, referring to fig. 1, the system for preparing uniform ultra-coarse tungsten powder includes: a doping unit 600 and a reduction unit 500.
According to an embodiment of the present invention, referring to fig. 1, the doping unit includes a stirring device 100, a spray drying tower 200, a heating apparatus 300, and a sieving device 400.
According to the embodiment of the present invention, the stirring assembly 11 is disposed in the stirring device 100, the stirring device 100 has a water inlet 101, a dopant inlet 102, a tungsten oxide inlet 103 and a dopant outlet 104, and is adapted to mix water, a dopant and tungsten oxide powder to obtain a dopant, and the dopant outlet 104 is disposed with a first discharge valve 13 and is adapted to discharge the uniformly mixed dopant, and the discharge speed can be controlled. Further, referring to fig. 2, the bottom of the stirring device 100 is provided with a stirrer 12, so that the tungsten oxide powder can be prevented from sinking to improve the uniformity of doping. It should be noted that, a person skilled in the art may select the type of the dopant according to actual needs as long as the doping of the tungsten oxide can be achieved, and for example, the dopant is at least one of sodium bicarbonate, lithium bicarbonate, potassium bicarbonate, sodium tungstate, sodium carbonate, lithium hydroxide, potassium tungstate, lithium tungstate, potassium carbonate, lithium carbonate, sodium hydroxide, and potassium hydroxide. Preferably, the stirring assembly 11 is centrally disposed within the stirring device 100, and the dope outlet 104 is centrally disposed at the bottom of the stirring device 100.
According to an embodiment of the present invention, referring to fig. 1 to 3, the spray drying tower 200 has a dope inlet 201, a gas inlet 202, a gas outlet 203 and a doped dry tungsten oxide outlet 204, wherein the dope inlet 201 is connected to the dope outlet 104 of the stirring apparatus 100, an outlet section of the dope inlet 201 is provided with a rotatable centrifugal atomizing disk 21, a second discharge valve 22 is provided at the doped dry tungsten oxide outlet 204, the gas inlet 202 is connected to a heating apparatus 300, the heating apparatus 300 is connected to a blower 700, and the gas outlet 203 is connected to an exhaust fan 800. Specifically, by turning on the blower 700, the exhaust fan 800 and the heating device 300, hot air can be supplied into the spray drying tower 200 from the air inlet 202, and the spray drying tower 200 is preheated, when the mixture is heated to a predetermined temperature, the centrifugal atomizing disk 21 is turned on, the rotation speed of the centrifugal atomizing disk 21 is set, then the first discharge valve 13 is turned on, and the feeding speed is controlled, at this time, the uniformly mixed dope solution in the stirring device 100 can be supplied to the centrifugal atomizing disk 21 through the dope solution outlet 104, the first discharge valve 13 and the dope solution inlet 201 in sequence, and is dispersed into mist droplets to be fully contacted with the hot air, the moisture is evaporated instantaneously, and the dried doped tungsten oxide powder is obtained, and the exhaust gas generated in the drying process is exhausted from the exhaust port 203 by the exhaust fan 800. Further, the stirring device 100 is located above the spray drying tower 200, and the platform 14 is arranged between the two, so that doping-drying can be integrally completed, the labor intensity is greatly reduced, and the production efficiency is improved.
It should be noted that, a person skilled in the art may select the type of the heating apparatus 300 according to actual needs as long as the above-mentioned functions can be achieved, for example, the heating apparatus 300 is an air heating apparatus 300. Meanwhile, the side wall of the spray drying tower 200 is provided with an observation window 23, so that the feeding speed of the dope in the spray drying tower 200 can be conveniently observed and controlled. Further, the dope inlet 201 is arranged at the center of the top of the spray drying tower 200, so that the wall sticking phenomenon can be avoided, and the dope droplets can be heated uniformly when descending, thereby improving the product quality. Further, in the height direction, the air inlet 202 is positioned above the air outlet 203, and the parallel flow type spray drying mode is adopted, so that liquid drops and hot air can flow in the same direction, although the temperature of the hot air is higher, the hot air enters the drying chamber and immediately contacts with the spray liquid drops, the indoor temperature is suddenly reduced, the wet bulb temperature of the material is basically unchanged, and therefore the drying can be carried out by adopting the higher air inlet temperature without influencing the product quality. Preferably, the outlet 204 for doped, dried tungsten oxide is centrally located at the bottom of the spray drying tower 200.
According to an embodiment of the present invention, the screening device 400 is connected to the doped dried tungsten oxide outlet 204 of the spray drying tower 200. Specifically, by opening the second discharge valve 22, the doped tungsten oxide powder that has been dried in the spray drying tower 200 is sequentially supplied to the screening device 400 from the doped dried tungsten oxide outlet 204 and the second discharge valve 22 to be screened, so that the abnormal coarse particles are removed, and the doped tungsten oxide powder with uniform particle size is obtained. It should be noted that, a person skilled in the art may select a specific type of the sieving device 400 according to actual needs as long as the function is achieved, for example, the sieving device 400 is a vibrating sieve. Further, in the height direction, the spray drying tower 200 is located above the screening device 400, so that the atomized droplets of the doping liquid can be instantly dried into powder in the spray drying tower 200 and then directly fall to the screening device 400 through the doped tungsten oxide drying outlet 204 at the bottom of the spray drying tower 200, and thus, the drying and screening can be integrally completed, the drying process and the screening process can be simultaneously performed, the labor intensity is greatly reduced, and the production efficiency is improved.
According to an embodiment of the present invention, referring to fig. 1, the reduction unit 500 has a doped dry tungsten oxide inlet 501, a hydrogen inlet 502 and an ultra-coarse tungsten particle tungsten powder outlet 503, the doped dry tungsten oxide inlet 501 is connected with an undersize outlet of the sieving device 400, and is adapted to supply the doped tungsten oxide which is dried in the spray drying tower 200 from the undersize outlet into the reduction unit 500 to be reduced by contacting with hydrogen, so as to obtain ultra-coarse tungsten powder. It should be noted that, a person skilled in the art may select a specific type of the reduction unit 500 according to actual needs as long as the above-mentioned function can be achieved, for example, the reduction unit 500 is a fifteen-tube high-temperature reduction furnace.
The inventors have found that by mixing tungsten oxide, water and a dopant in the stirring device 100 by the stirring module 11, that is, by using a liquid-solid doping method, the uniformity of doping can be ensured, and the doping amount can be precisely controlled, thereby improving the uniformity of tungsten powder particles. Then, the blower 700, the exhaust fan 800 and the heating device 300 are sequentially started, hot air is supplied into the spray drying tower 200 through the air inlet 202 to preheat the spray drying tower 200, when the spray drying tower is heated to a preset temperature, the centrifugal atomizing disk 21 is started, the rotating speed of the centrifugal atomizing disk 21 is set, then the first discharge valve 13, the second discharge valve 22 and the screening device 400 are started, the feeding speed is controlled, at the moment, the doping liquid is sent to the centrifugal atomizing disk 21 at the top of the spray drying tower 200 through the doping liquid outlet 104 at the bottom of the stirring device 100 and is dispersed into extremely small atomized liquid drops, the surface area of the doping liquid is greatly increased after being atomized, the atomized liquid drops are fully contacted with the hot air, instant drying can be completed, the obtained powdery doped tungsten oxide falls to the bottom of the spray drying tower 200, is sent to the screening device 400 through the doped dried tungsten oxide outlet 204, screening is performed, abnormal coarse particles are removed, exhaust gas generated during the drying process is exhausted from the exhaust port 203 by the exhaust fan 800. The materials are discharged from the bottom of the stirring device 100 and directly enter the spray drying tower 200 for drying, so that doping-drying is integrally completed, the labor intensity is greatly reduced, and the production efficiency is improved. Finally, the sieved doped tungsten oxide powder is supplied to a reduction unit 500 to be reduced by contacting with hydrogen, and ultra-coarse tungsten powder with high purity and uniform particle size distribution can be obtained, so that the preparation of coarse-particle tungsten carbide with few microstructure defects is possible.
In a second aspect of the present invention, the present invention provides a method for preparing ultra-coarse tungsten powder using the above system. According to an embodiment of the invention, with reference to fig. 4, the method comprises:
s100, supplying tungsten oxide, water and a doping agent into the stirring device for stirring, supplying the obtained doping liquid into the spray drying tower, drying the doping liquid under the action of hot air supplied by the heating equipment, and screening the obtained doped dried tungsten oxide by the screening device
In this step, tungsten oxide, water, and a dopant are supplied into a stirring apparatus through a tungsten oxide inlet, a water inlet, and a dopant inlet, respectively, and are stirred by a stirring unit and a stirrer, and the mixture is uniformly mixed to obtain a dope. Then starting a blower, an exhaust fan and heating equipment in sequence, supplying hot air into the spray drying tower from an air inlet and preheating, starting the centrifugal atomizing disk when the temperature is heated to a preset temperature, setting the rotating speed of the centrifugal atomizing disk, then opening a first discharge valve, a second discharge valve and a screening device in sequence, controlling the feeding speed at the doped liquid inlet of the spray drying tower, supplying the doped liquid to a centrifugal atomizing disc at the top of the spray drying tower from a stirring device, and is dispersed into tiny fog-like liquid drops, the fog-like liquid drops are contacted with hot air in a parallel flow way in the descending process in the air, the moisture is quickly evaporated, the mixture is instantly dried in the air into doped tungsten oxide powder, the doped tungsten oxide powder falls to the bottom of a spray drying tower, and the doped tungsten oxide powder enters a screening device through a doped tungsten oxide outlet and a second discharge valve to be screened, abnormal coarse particles are removed, and doped dry tungsten oxide powder with uniform particle size is obtained. Wherein the tungsten oxide feedstock comprises at least one of yellow tungsten and blue tungsten.
Further, the particle size of the tungsten oxide used is 20 to 80 μm. The inventors found that too large tungsten oxide particle size may cause non-uniform and insufficient doping, resulting in non-uniform particle size of the finally obtained tungsten powder; the tungsten oxide has too small a particle size, which is not favorable for obtaining coarse tungsten powder. And the dopant is an alkali metal salt, for example, the alkali metal salt includes at least one of sodium bicarbonate, lithium bicarbonate, potassium bicarbonate, sodium tungstate, sodium carbonate, lithium hydroxide, potassium tungstate, lithium tungstate, potassium carbonate, lithium carbonate, sodium hydroxide, and potassium hydroxide.
Meanwhile, in the mixing process of the stirring device, the mass ratio of the tungsten oxide to the water to the dopant is (1000-10000): (500-5000): (0.5 to 100). The inventor finds that by adopting the mass ratio in the range of the application, on one hand, the fluidity of the doping liquid and the uniformity and sufficiency of doping can be ensured, and on the other hand, the doping liquid fog drops can be ensured to be instantly and fully dried in a spray drying tower, so that the obtained tungsten oxide powder after doping has good dispersibility. And the temperature of the hot gas supplied by the heating device is 90-150 ℃. The inventor finds that if the temperature is too low, the doping liquid fog drops cannot be instantly and fully dried in the descending process, and the drying efficiency is low; if the temperature is too high, thermal denaturation of the doped tungsten oxide may occur.
S200: the undersize material obtained by the screening device is supplied to the reduction unit to be in contact with hydrogen gas for reduction
In the step, the tungsten oxide powder after doping and sieving is supplied to a reduction unit from a tungsten oxide inlet after drying and doping, hydrogen is supplied to the reduction unit through a hydrogen inlet, the tungsten oxide powder after doping and the hydrogen are subjected to contact reduction in the reduction unit to obtain tungsten powder, and the tungsten powder is promoted to grow thick in the reduction process due to the fact that the tungsten oxide is doped with alkali metal elements, so that ultra-thick tungsten powder is finally obtained. Further, the reduction temperature is 980-3H is used as the reference value. The particle size of the ultra-coarse particle tungsten powder is 20-100 mu m. The inventor finds that the volatilization of the tungsten oxide increases with the increase of the temperature, and the higher the reduction temperature, the more the tungsten oxide and the water vapor are promoted to form volatile hydrate, and the tungsten oxide is reduced on the surfaces of the reduced tungsten powder particles and the low-valence tungsten oxide, so that the original particles are thickened. Therefore, if the reduction temperature is too lowTungsten powder which is not favorable for forming coarse particles; if the reduction temperature is too high, the tungsten powder particles obtained may be non-uniform. Meanwhile, if the reduction time is too short, incomplete reduction may be caused, and the obtained tungsten powder has a fine particle size; if the reduction time is too long, the obtained tungsten powder particles are not uniform and resources are wasted. In addition, if the hydrogen flow is too large, the water vapor of the reduction product can be discharged in time, so that the reduction reaction speed is accelerated, and the fine tungsten powder can be obtained easily; if the hydrogen flow rate is too small, the reduction time is long.
The following embodiments of the present invention are described in detail, and it should be noted that the following embodiments are exemplary only, and are not to be construed as limiting the present invention. In addition, all reagents used in the following examples are commercially available or can be synthesized according to methods herein or known, and are readily available to those skilled in the art for reaction conditions not listed, if not explicitly stated.
Example 1
Step 1: and (4) screening the yellow tungsten oversize product to remove impurities and coarse particles in the oversize product, and weighing for later use after screening.
Step 2: preparing NaHCO with corresponding concentration in a stirring device according to the weight of the tungsten oxide sieved in the step 13The concentration of the sodium element in the solution was 100 ppm.
And step 3: and (3) starting a stirring assembly and a stirrer, adding the tungsten oxide oversize material (the particle size is 30 micrometers) screened in the step (1) into a stirring device, and controlling the solid-liquid ratio to be 1.5:1 to ensure the fluidity of the material.
And 4, step 4: stirring for 20min, after guaranteeing the misce bene, opening forced draught blower, exhaust fan and heating device, preheat the spray drying tower, when heating device's hot air outlet temperature reached 110 ℃, open centrifugal atomizing disk, set up centrifugal atomizing disk rotational speed, then open first discharge valve, second discharge valve and shale shaker, control agitating unit's unloading speed (be spray drying tower's input speed), carry out spray drying, and sieve, get rid of unusual coarse granule.
Step (ii) of5: respectively supplying the prepared doped tungsten oxide and hydrogen to a fifteen-tube high-temperature reduction furnace through a doped dried tungsten oxide inlet and a doped hydrogen inlet for high-temperature reduction at 1040 ℃ for 6h, filling the furnace with the tungsten oxide and the hydrogen at a hydrogen flow rate of 20m, and filling the furnace with the tungsten oxide and the hydrogen3And h, obtaining the ultra-coarse tungsten powder with the particle size of 25 mu m.
Example 2
Step 1: and (4) screening the yellow tungsten oversize product to remove impurities and coarse particles in the oversize product, and weighing for later use after screening.
Step 2: preparing NaHCO with corresponding concentration in a stirring device according to the weight of the tungsten oxide sieved in the step 13The concentration of the sodium element in the solution was 300 ppm.
And step 3: and (3) starting a stirring assembly and a stirrer, adding the tungsten oxide oversize material (the particle size is 45 microns) screened in the step (1) into a stirring device, and controlling the solid-liquid ratio to be 2:1 to ensure the fluidity of the material.
And 4, step 4: stirring for 30min, after guaranteeing the misce bene, opening forced draught blower, exhaust fan and heating device, preheat the spray drying tower, when heating device's hot air outlet temperature reached 130 ℃, open centrifugal atomizing disk, set up centrifugal atomizing disk rotational speed, then open first discharge valve, second discharge valve and shale shaker, control agitating unit's unloading speed (be spray drying tower's input speed), carry out spray drying, and sieve, get rid of unusual coarse granule.
And 5: respectively supplying the prepared doped tungsten oxide and hydrogen to a fifteen-tube high-temperature reduction furnace through a doped dried tungsten oxide inlet and a doped hydrogen inlet for high-temperature reduction at 1070 ℃ for 8h, filling the furnace with the tungsten oxide and the hydrogen at the hydrogen flow rate of 16m, and filling the furnace with the tungsten oxide and the hydrogen at the temperature of 1070 DEG C3/h, obtaining the ultra-coarse tungsten powder with the particle size of 45 mu m.
Example 3
Step 1: and (4) screening the yellow tungsten oversize product to remove impurities and coarse particles in the oversize product, and weighing for later use after screening.
Step 2: preparing NaHCO with corresponding concentration in a stirring device according to the weight of the tungsten oxide sieved in the step 13The solution was measured at a sodium concentration of 400 ppm.
And step 3: and (3) starting a stirring assembly and a stirrer, adding the tungsten oxide oversize material (the particle size is 45 microns) screened in the step (1) into a stirring device, and controlling the solid-liquid ratio to be 1:1 to ensure the fluidity of the material.
And 4, step 4: stirring for 40min, after guaranteeing the misce bene, opening forced draught blower, exhaust fan and heating device, preheat the spray drying tower, when heating device's hot air outlet temperature reached 140 ℃, open centrifugal atomizing disk, set up centrifugal atomizing disk rotational speed, then open first discharge valve, second discharge valve and shale shaker, control agitating unit's unloading speed (be spray drying tower's input speed), carry out spray drying, and sieve, get rid of unusual coarse grain.
And 5: respectively supplying the prepared doped tungsten oxide and hydrogen to a fifteen-tube high-temperature reduction furnace through a doped dried tungsten oxide inlet and a doped hydrogen inlet for high-temperature reduction at 1100 ℃ for 9h, filling the furnace with the tungsten oxide and the hydrogen at a hydrogen flow rate of 15m, and filling the furnace with the tungsten oxide and the hydrogen at the temperature of 1100 DEG C3And h, obtaining the ultra-coarse tungsten powder with the particle size of 50 mu m.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. A system for preparing uniform ultra-coarse tungsten powder, comprising:
a doping unit, the doping unit comprising:
the stirring device is internally provided with a stirring assembly, the stirring device is provided with a water inlet, a doping agent inlet, a tungsten oxide inlet and a doping liquid outlet, and the doping liquid outlet is provided with a first discharge valve;
the spray drying tower is provided with a doping liquid inlet, an air outlet and a doped dried tungsten oxide outlet, the doping liquid inlet is connected with the doping liquid outlet, the outlet section of the doping liquid inlet is provided with a rotatable centrifugal atomizing disc, and the doped dried tungsten oxide outlet is provided with a second discharge valve;
the heating equipment is connected with the air inlet;
the screening device is connected with the doped dried tungsten oxide outlet;
the reduction unit is provided with a hydrogen inlet, a doped dry tungsten oxide inlet and an ultra-coarse tungsten particle tungsten powder outlet, and the doped dry tungsten oxide inlet is connected with a screen underflow outlet of the screening device.
2. The system for preparing uniform ultra-coarse tungsten powder as claimed in claim 1, wherein a stirrer is provided at the bottom of the stirring device.
3. The system for preparing uniform ultra-coarse tungsten powder according to claim 1 or 2, wherein the stirring device is located above the spray drying tower in a height direction.
4. The system for preparing uniform ultra-coarse tungsten powder according to claim 1, wherein the side wall of the spray drying tower is provided with an observation window.
5. The tungsten oxide powder doping system of claim 1 or 4, wherein the doping liquid inlet is provided at a central position of a top of the spray drying tower.
6. The system for preparing uniform ultra-coarse tungsten powder according to claim 5, wherein the gas inlet is located above the gas outlet in the height direction.
7. The system for preparing uniform ultra-coarse tungsten powder according to claim 1, wherein the heating device is an air heating device.
8. The system for preparing uniform ultra-coarse tungsten powder according to claim 1, wherein the spray drying tower is located above the sieving device in the height direction;
optionally, the screening device is a vibrating screen.
9. A method of producing ultra-coarse tungsten powder using the system of any one of claims 1-8, comprising:
(1) feeding tungsten oxide, water and a doping agent into the stirring device for stirring, feeding the obtained doping liquid into the spray drying tower, drying the doping liquid under the action of hot air supplied by the heating equipment, and screening the obtained doped dried tungsten oxide by the screening device;
(2) and feeding the undersize obtained by the screening device to the reduction unit to be in contact with hydrogen for reduction so as to obtain ultra-coarse tungsten powder.
10. The method according to claim 9, wherein in step (1), the tungsten oxide has a particle size of 20 to 80 μm;
optionally, in the step (1), the dopant is an alkali metal salt, and the mass ratio of the tungsten oxide, the water and the dopant is (1000 to 10000): (500-5000): (0.5 to 100);
optionally, in step (1), the temperature of the hot gas supplied by the heating device is 90-150 ℃;
optionally, in the step (2), the reduction temperature is 980-1150 ℃, the time is 4-10 h, and the hydrogen flow is 14-20 m3/h；
Optionally, in the step (2), the particle size of the ultra-coarse tungsten powder is 20-100 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010878334.4A CN112045198B (en) | 2020-08-27 | 2020-08-27 | System and method for preparing uniform ultra-coarse particle tungsten powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010878334.4A CN112045198B (en) | 2020-08-27 | 2020-08-27 | System and method for preparing uniform ultra-coarse particle tungsten powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112045198A true CN112045198A (en) | 2020-12-08 |
| CN112045198B CN112045198B (en) | 2023-03-28 |
Family
ID=73600228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010878334.4A Active CN112045198B (en) | 2020-08-27 | 2020-08-27 | System and method for preparing uniform ultra-coarse particle tungsten powder |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112045198B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118458776A (en) * | 2024-07-10 | 2024-08-09 | 株洲硬质合金集团有限公司 | Ultra-coarse tungsten carbide powder, super-hard alloy and preparation method |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58130206A (en) * | 1982-01-28 | 1983-08-03 | Tokyo Tungsten Co Ltd | Production of doped tungsten powder |
| CN1565782A (en) * | 2003-06-12 | 2005-01-19 | 中南大学 | Method for preparing nano-grade tungsten-based composite powder by sol-spray drying-thermal reduction |
| CN1686644A (en) * | 2005-05-10 | 2005-10-26 | 自贡硬质合金有限责任公司 | Production method of tungsten carbide base ball shaped thermal spray coating powder |
| CN102249234A (en) * | 2011-04-29 | 2011-11-23 | 潮州翔鹭钨业有限公司 | Preparation method of ultra-coarse tungsten carbide powder |
| CN102489714A (en) * | 2011-12-09 | 2012-06-13 | 北京科技大学 | Method for producing extra-coarse tungsten powder |
| CN103056378A (en) * | 2013-02-02 | 2013-04-24 | 北京科技大学 | Preparation method for sphere-like tungsten powder |
| CN105149608A (en) * | 2015-09-30 | 2015-12-16 | 江西耀升钨业股份有限公司 | Manufacturing technology of super-coarse tungsten powder |
| CN109128141A (en) * | 2018-09-30 | 2019-01-04 | 合肥工业大学 | A kind of preparation method of nanometer WC-Co composite powder |
| CN109365829A (en) * | 2018-12-21 | 2019-02-22 | 合肥工业大学 | A kind of method of high temperature spray-drying, short route preparation nanometer WC-Co composite powder |
-
2020
- 2020-08-27 CN CN202010878334.4A patent/CN112045198B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58130206A (en) * | 1982-01-28 | 1983-08-03 | Tokyo Tungsten Co Ltd | Production of doped tungsten powder |
| CN1565782A (en) * | 2003-06-12 | 2005-01-19 | 中南大学 | Method for preparing nano-grade tungsten-based composite powder by sol-spray drying-thermal reduction |
| CN1686644A (en) * | 2005-05-10 | 2005-10-26 | 自贡硬质合金有限责任公司 | Production method of tungsten carbide base ball shaped thermal spray coating powder |
| CN102249234A (en) * | 2011-04-29 | 2011-11-23 | 潮州翔鹭钨业有限公司 | Preparation method of ultra-coarse tungsten carbide powder |
| CN102489714A (en) * | 2011-12-09 | 2012-06-13 | 北京科技大学 | Method for producing extra-coarse tungsten powder |
| CN103056378A (en) * | 2013-02-02 | 2013-04-24 | 北京科技大学 | Preparation method for sphere-like tungsten powder |
| CN105149608A (en) * | 2015-09-30 | 2015-12-16 | 江西耀升钨业股份有限公司 | Manufacturing technology of super-coarse tungsten powder |
| CN109128141A (en) * | 2018-09-30 | 2019-01-04 | 合肥工业大学 | A kind of preparation method of nanometer WC-Co composite powder |
| CN109365829A (en) * | 2018-12-21 | 2019-02-22 | 合肥工业大学 | A kind of method of high temperature spray-drying, short route preparation nanometer WC-Co composite powder |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118458776A (en) * | 2024-07-10 | 2024-08-09 | 株洲硬质合金集团有限公司 | Ultra-coarse tungsten carbide powder, super-hard alloy and preparation method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112045198B (en) | 2023-03-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103189139B (en) | The manufacture method of the manufacture method of oxide catalyst, oxide catalyst, the manufacture method of unsaturated acids and unsaturated nitrile | |
| WO2007094114A1 (en) | Continuous particulate high-temperature gas treatment apparatus and method of treating | |
| CN107983335A (en) | Composite oxide catalysts and its manufacture method | |
| CN112045198B (en) | System and method for preparing uniform ultra-coarse particle tungsten powder | |
| KR20150132375A (en) | Method for the use of slurries in spray pyrolysis for the production of non-hollow, porous particles | |
| KR20010040770A (en) | Method for Producing Lithium-Transition Metal Mixtures | |
| WO2021230189A1 (en) | Solid electrolyte producing method | |
| JPH07206568A (en) | Production of granulated igniter | |
| JP3092041B2 (en) | Method for producing Li2O particles | |
| CN213699551U (en) | Powder doping system | |
| JP6616216B2 (en) | Method for producing positive electrode active material for lithium ion battery | |
| JP6321357B2 (en) | Method for producing finely baked alumina powder | |
| JP6616217B2 (en) | Method for producing positive electrode active material for lithium ion battery | |
| US9018131B2 (en) | Chemical activation of carbon via a gas atomization method | |
| CN115196970A (en) | Preparation method of high-fluidity AlON spherical powder | |
| JP2021190427A (en) | Manufacturing method of solid electrolyte | |
| JP2018016519A (en) | Production method for composite metal hydroxide particles with high tap density | |
| CN112226720A (en) | Spray granulation preparation method of metal-ceramic composite powder suitable for atmospheric plasma spraying | |
| JP7134590B2 (en) | Method for producing crack-free lithium-ion battery positive electrode active material precursor | |
| JP6616218B2 (en) | Method for producing positive electrode active material for lithium ion battery | |
| CN107074556A (en) | Prepare the apparatus and method of basic activated carbon | |
| JP7420296B1 (en) | Method for producing sulfide solid electrolyte powder and apparatus for producing the same | |
| CN116003140B (en) | Granulating method of low-bulk-density compound agent | |
| CN211847171U (en) | Production equipment of ammonium paratungstate with high Fischer and low apparent density | |
| WO2022131361A1 (en) | Method for producing carbon precursor particles and carbonaceous material for secondary battery negative electrode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |