CN113652588A - Process for producing vanadium iron nitride from ammonium metavanadate - Google Patents
Process for producing vanadium iron nitride from ammonium metavanadate Download PDFInfo
- Publication number
- CN113652588A CN113652588A CN202110893817.6A CN202110893817A CN113652588A CN 113652588 A CN113652588 A CN 113652588A CN 202110893817 A CN202110893817 A CN 202110893817A CN 113652588 A CN113652588 A CN 113652588A
- Authority
- CN
- China
- Prior art keywords
- powder
- vanadium pentoxide
- ammonium metavanadate
- metavanadate
- steps
- 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.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
- C22C29/16—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on nitrides
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/05—Mixtures of metal powder with non-metallic powder
- C22C1/051—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor
- C22C1/053—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor with in situ formation of hard compounds
- C22C1/055—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor with in situ formation of hard compounds using carbon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/05—Mixtures of metal powder with non-metallic powder
- C22C1/051—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor
- C22C1/053—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor with in situ formation of hard compounds
- C22C1/056—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor with in situ formation of hard compounds using gas
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C35/00—Master alloys for iron or steel
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention discloses a new process for producing ferrovanadium nitride by ammonium metavanadate, which comprises the following steps of S1: preparing vanadium pentoxide, weighing 50-80% of ammonium metavanadate powder according to mass fraction, placing the ammonium metavanadate powder into heating equipment, adding water for dissolving, filtering to obtain a sodium metavanadate solution, adding ammonium sulfate into the obtained sodium metavanadate solution for precipitation, filtering to obtain a sodium metavanadate solid, and calcining the sodium metavanadate solid to obtain vanadium pentoxide; s2: preparing vanadium pentoxide powder, and grinding the vanadium pentoxide obtained in the step S1 in grinding equipment for 40-50 minutes to obtain vanadium pentoxide powder; the invention has the beneficial effects that: the vanadium nitride iron produced by using the high-purity vanadium pentoxide as the raw material has high purity and few impurities, and the vanadium nitride iron is prepared by using the ammonium metavanadate.
Description
Technical Field
The invention relates to the technical field of ferroalloy preparation, in particular to a new process for producing ferrovanadium nitride from ammonium metavanadate.
Background
The most important application field of vanadium is the metallurgy field, and vanadium microalloying is mainly carried out by adding vanadium into steel in the form of alloy additive, so that the comprehensive performance of steel is improved. The carbide and nitride of vanadium, especially nitride, can promote the grain refinement and precipitation strengthening in steel, thus improve the toughness, strength, corrosion resistance, wear resistance and thermal fatigue resistance of steel, and make it possess good weldability. At present, the vanadium-containing steelmaking additive in steel mainly comprises ferrovanadium, vanadium nitride and ferrovanadium nitride. The ferrovanadium nitride has the advantages of high density and high nitrogen content, and is a more excellent vanadium alloy additive. When the existing ferrovanadium nitride is produced, the production process steps are complicated, the consumption is excessive in the production process, and the production cost is high.
Disclosure of Invention
The invention aims to provide a novel process for producing ferrovanadium nitride from ammonium metavanadate, so as to solve the problems in the background technology.
In order to achieve the purpose, the invention provides a new process for producing ferrovanadium nitride by ammonium metavanadate, which comprises the following steps:
s1: preparing vanadium pentoxide, weighing 50-80% of ammonium metavanadate powder according to mass fraction, placing the ammonium metavanadate powder into heating equipment, adding water for dissolving, filtering to obtain a sodium metavanadate solution, adding ammonium sulfate into the obtained sodium metavanadate solution for precipitation, filtering to obtain a sodium metavanadate solid, and calcining the sodium metavanadate solid to obtain vanadium pentoxide;
s2: preparing vanadium pentoxide powder, and grinding the vanadium pentoxide obtained in the step S1 in grinding equipment for 40-50 minutes to obtain vanadium pentoxide powder;
s3: preparing mixed powder, weighing 20-40% of graphite carbon powder and 30-60% of iron powder respectively according to the mass fraction, and then mixing the vanadium pentoxide powder obtained in S2 with the weighed graphite carbon powder and iron powder to obtain mixed powder;
s4: and preparing ferrovanadium nitride, namely putting the mixed powder obtained in the step S3 into a nitriding kiln for reduction and nitridation, and cooling to obtain the ferrovanadium nitride.
Preferably, the S1 further comprises ammonium metavanadate powder, wherein the heating dissolution temperature is 95-105 ℃, and after dissolution, the pH value is adjusted to 8.5-10 by using a sodium hydroxide solution.
Preferably, the temperature for calcining the sodium metavanadate solid is 580-750 ℃.
Preferably, the weight ratio of the ammonium metavanadate to the water in the S1 is 2: 5.
Preferably, the particle size of the vanadium pentoxide powder in S2 is 200 meshes.
Preferably, the particle size of the graphite carbon powder in the S3 is 200 meshes, the purity is 95-98%, and the particle size of the iron powder is 100 meshes, and the purity is 95-99%.
Preferably, the pressure in the kiln cavity in the S4 is 25-45Pa, the reaction temperature in the nitriding kiln is 1700-1850 ℃, and the nitriding time is 30-50 minutes.
Preferably, the ratio of the vanadium pentoxide powder to the graphite carbon powder to the iron powder is 5:2: 4.
Compared with the prior art, the invention has the beneficial effects that:
1. the vanadium nitride iron produced by using the high-purity vanadium pentoxide as the raw material has high purity and less impurities.
2. The method can directly prepare the ferrovanadium nitride from the ammonium metavanadate, has fewer steps, requires lower energy consumption in the production process, can save resources and has lower production cost.
Detailed Description
The invention provides a technical scheme that: the new process for producing ferric vanadium nitride from ammonium metavanadate comprises the following steps:
s1: preparing vanadium pentoxide, weighing 50-80% of ammonium metavanadate powder according to mass fraction, placing the ammonium metavanadate powder into heating equipment, adding water for dissolving, filtering to obtain a sodium metavanadate solution, adding ammonium sulfate into the obtained sodium metavanadate solution for precipitation, filtering to obtain a sodium metavanadate solid, and calcining the sodium metavanadate solid to obtain vanadium pentoxide;
s2: preparing vanadium pentoxide powder, and grinding the vanadium pentoxide obtained in the step S1 in grinding equipment for 40-50 minutes to obtain vanadium pentoxide powder;
s3: preparing mixed powder, weighing 20-40% of graphite carbon powder and 30-60% of iron powder respectively according to the mass fraction, and then mixing the vanadium pentoxide powder obtained in S2 with the weighed graphite carbon powder and iron powder to obtain mixed powder;
s4: and preparing ferrovanadium nitride, namely putting the mixed powder obtained in the step S3 into a nitriding kiln for reduction and nitridation, and cooling to obtain the ferrovanadium nitride.
Further, the S1 also comprises ammonium metavanadate powder, the heating and dissolving temperature is 95-105 ℃, and after dissolution, the pH value is adjusted to 8.5-10 by using a sodium hydroxide solution.
Further, the temperature for calcining the sodium metavanadate solid is 580-750 ℃.
Further, the weight ratio of the ammonium metavanadate to the water in the S1 is 2: 5.
Further, the particle size of the vanadium pentoxide powder in the S2 is 200 meshes.
Further, the granularity of the graphite carbon powder in the S3 is 200 meshes, the purity is 95-98%, and the granularity of the iron powder is 100 meshes, and the purity is 95-99%.
Further, the pressure in the kiln cavity in the S4 is 25-45Pa, the reaction temperature in the nitriding kiln is 1700-1850 ℃, and the nitriding time is 30-50 minutes.
Further, the ratio of the vanadium pentoxide powder to the graphite carbon powder to the iron powder is 5:2: 4.
Example 1
The new process for producing ferric vanadium nitride from ammonium metavanadate comprises the following steps:
s1: preparing vanadium pentoxide, weighing 55% of ammonium metavanadate powder according to mass fraction, placing the ammonium metavanadate powder into heating equipment, adding water to dissolve the ammonium metavanadate powder, wherein the weight ratio of ammonium metavanadate to water is 2:5, the heating dissolution temperature is 95 ℃, adjusting the pH value to 8.5 by using a sodium hydroxide solution after dissolution, filtering to obtain a sodium metavanadate solution, adding ammonium sulfate into the obtained sodium metavanadate solution to precipitate, filtering to obtain a sodium metavanadate solid, calcining the sodium metavanadate solid, and calcining the sodium metavanadate solid at the calcining temperature of 600 ℃ to obtain vanadium pentoxide;
s2: preparing vanadium pentoxide powder, namely grinding the vanadium pentoxide obtained in the step S1 in grinding equipment for 40 minutes to obtain vanadium pentoxide powder, wherein the particle size of the vanadium pentoxide powder is 200 meshes;
s3: preparing mixed powder, weighing 25% of graphite carbon powder and 37% of iron powder respectively according to the mass fraction, then mixing the vanadium pentoxide powder obtained in S2 with the weighed graphite carbon powder and iron powder, wherein the granularity of the graphite carbon powder is 200 meshes, the purity is 95-98%, the granularity of the iron powder is 100 meshes, the purity is 95-99%, and the ratio of the vanadium pentoxide powder to the graphite carbon powder to the iron powder is 5:2:4 to obtain the mixed powder;
s4: and preparing ferrovanadium nitride, namely putting the mixed powder obtained in the step S3 into a nitriding kiln for reduction and nitridation, wherein the pressure in a kiln cavity is 25Pa, the reaction temperature in the nitriding kiln is 1750 ℃, and the nitriding time is 30 minutes, and cooling are carried out to obtain the ferrovanadium nitride.
Example 2
The new process for producing ferric vanadium nitride from ammonium metavanadate comprises the following steps:
s1: preparing vanadium pentoxide, weighing 70% of ammonium metavanadate powder according to mass fraction, placing the ammonium metavanadate powder into heating equipment, adding water to dissolve the ammonium metavanadate powder, wherein the weight ratio of ammonium metavanadate to water is 2:5, the heating dissolution temperature is 100 ℃, adjusting the pH value to 9 by using a sodium hydroxide solution after dissolution, filtering to obtain a sodium metavanadate solution, adding ammonium sulfate into the obtained sodium metavanadate solution to precipitate, filtering to obtain a sodium metavanadate solid, calcining the sodium metavanadate solid, and calcining the sodium metavanadate solid at the calcining temperature of 700 ℃ to obtain vanadium pentoxide;
s2: preparing vanadium pentoxide powder, namely grinding the vanadium pentoxide obtained in the step S1 in grinding equipment for 45 minutes to obtain vanadium pentoxide powder, wherein the particle size of the vanadium pentoxide powder is 200 meshes;
s3: preparing mixed powder, weighing 30% of graphite carbon powder and 45% of iron powder respectively according to the mass fraction, then mixing the vanadium pentoxide powder obtained in S2 with the weighed graphite carbon powder and iron powder, wherein the granularity of the graphite carbon powder is 200 meshes, the purity is 95-98%, the granularity of the iron powder is 100 meshes, the purity is 95-99%, and the ratio of the vanadium pentoxide powder to the graphite carbon powder to the iron powder is 5:2:4 to obtain the mixed powder;
s4: and preparing ferrovanadium nitride, namely putting the mixed powder obtained in the step S3 into a nitriding kiln for reduction nitriding, wherein the pressure in a kiln cavity is 30Pa, the reaction temperature in the nitriding kiln is 1800 ℃, and the nitriding time is 40 minutes, and cooling are carried out to obtain the ferrovanadium nitride.
Example 3
The new process for producing ferric vanadium nitride from ammonium metavanadate comprises the following steps:
s1: preparing vanadium pentoxide, weighing 75% of ammonium metavanadate powder by mass, placing the ammonium metavanadate powder into heating equipment, adding water to dissolve the ammonium metavanadate powder, wherein the weight ratio of ammonium metavanadate to water is 2:5, the heating dissolution temperature is 105 ℃, adjusting the pH value to 10 by using a sodium hydroxide solution after dissolution, filtering to obtain a sodium metavanadate solution, adding ammonium sulfate into the obtained sodium metavanadate solution to precipitate, filtering to obtain a sodium metavanadate solid, calcining the sodium metavanadate solid, and calcining the sodium metavanadate solid at the calcining temperature of 750 ℃ to obtain vanadium pentoxide;
s2: preparing vanadium pentoxide powder, namely grinding the vanadium pentoxide obtained in the step S1 in grinding equipment for 50 minutes to obtain vanadium pentoxide powder, wherein the particle size of the vanadium pentoxide powder is 200 meshes;
s3: preparing mixed powder, weighing 37% of graphite carbon powder and 55% of iron powder respectively according to the mass fraction, then mixing the vanadium pentoxide powder obtained in S2 with the weighed graphite carbon powder and iron powder, wherein the granularity of the graphite carbon powder is 200 meshes, the purity is 95-98%, the granularity of the iron powder is 100 meshes, the purity is 95-99%, and the ratio of the vanadium pentoxide powder to the graphite carbon powder to the iron powder is 5:2:4 to obtain the mixed powder;
s4: and (3) preparing ferrovanadium nitride, namely putting the mixed powder obtained in the step S3 into a nitriding kiln for reduction and nitridation, wherein the pressure in a kiln cavity is 45Pa, the reaction temperature in the nitriding kiln is 1850 ℃, and the nitriding time is 50 minutes, and cooling to obtain the ferrovanadium nitride.
In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "disposed," "connected," "secured," "screwed" and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; the terms may be directly connected or indirectly connected through an intermediate, and may be communication between two elements or interaction relationship between two elements, unless otherwise specifically limited, and the specific meaning of the terms in the present invention will be understood by those skilled in the art according to specific situations.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. The new process for producing the ferric vanadium nitride by the ammonium metavanadate is characterized by comprising the following steps of:
s1: preparing vanadium pentoxide, weighing 50-80% of ammonium metavanadate powder according to mass fraction, placing the ammonium metavanadate powder into heating equipment, adding water for dissolving, filtering to obtain a sodium metavanadate solution, adding ammonium sulfate into the obtained sodium metavanadate solution for precipitation, filtering to obtain a sodium metavanadate solid, and calcining the sodium metavanadate solid to obtain vanadium pentoxide;
s2: preparing vanadium pentoxide powder, and grinding the vanadium pentoxide obtained in the step S1 in grinding equipment for 40-50 minutes to obtain vanadium pentoxide powder;
s3: preparing mixed powder, weighing 20-40% of graphite carbon powder and 30-60% of iron powder respectively according to the mass fraction, and then mixing the vanadium pentoxide powder obtained in S2 with the weighed graphite carbon powder and iron powder to obtain mixed powder;
s4: and preparing ferrovanadium nitride, namely putting the mixed powder obtained in the step S3 into a nitriding kiln for reduction and nitridation, and cooling to obtain the ferrovanadium nitride.
2. The new process for producing ferrovanadium nitride from ammonium metavanadate according to claim 1, wherein the process comprises the following steps: the S1 also comprises ammonium metavanadate powder, the heating and dissolving temperature is 95-105 ℃, and after dissolution, the pH value is adjusted to 8.5-10 by using a sodium hydroxide solution.
3. The new process for producing ferrovanadium nitride from ammonium metavanadate according to claim 1, wherein the process comprises the following steps: the temperature for calcining the sodium metavanadate solid is 580-750 ℃.
4. The new process for producing ferrovanadium nitride from ammonium metavanadate according to claim 1, wherein the process comprises the following steps: the weight ratio of the ammonium metavanadate to the water in the S1 is 2: 5.
5. The new process for producing ferrovanadium nitride from ammonium metavanadate according to claim 1, wherein the process comprises the following steps: and the granularity of vanadium pentoxide powder in the S2 is 200 meshes.
6. The new process for producing ferrovanadium nitride from ammonium metavanadate according to claim 1, wherein the process comprises the following steps: the granularity of the graphite carbon powder in the S3 is 200 meshes, the purity is 95-98%, and the granularity of the iron powder is 100 meshes, and the purity is 95-99%.
7. The new process for producing ferrovanadium nitride from ammonium metavanadate according to claim 1, wherein the process comprises the following steps: and the pressure in the kiln cavity in the S4 is 25-45Pa, the reaction temperature in the nitriding kiln is 1700-1850 ℃, and the nitriding time is 30-50 minutes.
8. The new process for producing ferrovanadium nitride from ammonium metavanadate according to claim 1, wherein the process comprises the following steps: the ratio of the vanadium pentoxide powder to the graphite carbon powder to the iron powder is 5:2: 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110893817.6A CN113652588A (en) | 2021-08-05 | 2021-08-05 | Process for producing vanadium iron nitride from ammonium metavanadate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110893817.6A CN113652588A (en) | 2021-08-05 | 2021-08-05 | Process for producing vanadium iron nitride from ammonium metavanadate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113652588A true CN113652588A (en) | 2021-11-16 |
Family
ID=78478414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110893817.6A Pending CN113652588A (en) | 2021-08-05 | 2021-08-05 | Process for producing vanadium iron nitride from ammonium metavanadate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113652588A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102976290A (en) * | 2011-09-06 | 2013-03-20 | 河南昱千鑫金属科技有限公司 | Preparation method of iron vanadium nitride |
| CN106399786A (en) * | 2016-11-25 | 2017-02-15 | 南通汉瑞新材料科技有限公司 | Novel method for preparing vanadium-nitrogen alloy |
-
2021
- 2021-08-05 CN CN202110893817.6A patent/CN113652588A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102976290A (en) * | 2011-09-06 | 2013-03-20 | 河南昱千鑫金属科技有限公司 | Preparation method of iron vanadium nitride |
| CN106399786A (en) * | 2016-11-25 | 2017-02-15 | 南通汉瑞新材料科技有限公司 | Novel method for preparing vanadium-nitrogen alloy |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106048284B (en) | A kind of VN alloy and preparation method thereof | |
| CN106834775B (en) | A kind of method of carbon thermal reduction and Nitration synthesis ferrovanadium nitride | |
| CN101476074B (en) | Carbon-nitrogen-vanadium alloy containing titanium and manufacturing method thereof | |
| CN101619411B (en) | Steel making nitriding silicon-manganese alloy and preparation method thereof | |
| CN103305739A (en) | High-nitrogen vanadium-nitrogen alloy VN18 and production method thereof | |
| CN112853190B (en) | High-entropy cast iron and preparation method thereof | |
| CN108823452A (en) | A method of preparing ferrovanadium nitride | |
| CN103981425A (en) | Silicon-titanium-aluminum nitration material, and preparation method and application thereof | |
| CN103160721A (en) | High-hardness heat-resistant magnesium alloy | |
| CN104404333B (en) | A method of it being used to prepare the feedstock composition of superelevation vanadium nitride and superelevation vanadium nitride is prepared using the raw material | |
| CN103602814B (en) | A kind of preparation method of alloy of vanadium nitride | |
| CN1775663A (en) | Method for synthesizing manganese nitride by microwave | |
| CN113652588A (en) | Process for producing vanadium iron nitride from ammonium metavanadate | |
| CN112813331A (en) | Co-Cr-Fe-Ni-Mn eutectic high-entropy cast iron, preparation method and application | |
| CN114535591B (en) | Method for preparing alloy powder based on surface nanocrystallization treatment | |
| CN110791700A (en) | Preparation method of high-carbon ferrochrome | |
| CN112725681B (en) | Iron-cobalt-nickel-manganese-copper high-entropy cast iron and preparation method and application thereof | |
| CN101514406A (en) | Method for producing nitridized siliconmanganese alloy | |
| CN114182152A (en) | Preparation method of vanadium-nitrogen alloy | |
| CN103305710B (en) | Titanium-nitrogen alloy and preparation process thereof | |
| CN110964972A (en) | Rare earth silicon-nitrogen-vanadium alloy and preparation method and application thereof | |
| CN102409186B (en) | Silicon-based nitroalloy used for molten steel nitrogen microalloyed treatment and production technology thereof | |
| CN108193120A (en) | A kind of high nitrogen type VN alloy V77N19 and preparation method thereof | |
| CN110923556A (en) | Method for smelting ferrovanadium by adopting iron particles and steel scraps | |
| CN110438392A (en) | A kind of nitrogenous composite inoculant greatly improving cast iron |
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 | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20211116 |