CN110283998A - The control method of content of vanadium and alloying component in vanadium iron metallurgical slag - Google Patents
The control method of content of vanadium and alloying component in vanadium iron metallurgical slag Download PDFInfo
- Publication number
- CN110283998A CN110283998A CN201910721722.9A CN201910721722A CN110283998A CN 110283998 A CN110283998 A CN 110283998A CN 201910721722 A CN201910721722 A CN 201910721722A CN 110283998 A CN110283998 A CN 110283998A
- Authority
- CN
- China
- Prior art keywords
- vanadium
- content
- control method
- alloying component
- slag
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D7/00—Casting ingots, e.g. from ferrous metals
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B34/00—Obtaining refractory metals
- C22B34/20—Obtaining niobium, tantalum or vanadium
- C22B34/22—Obtaining vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/04—Dry methods smelting of sulfides or formation of mattes by aluminium, other metals or silicon
-
- 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
Abstract
The invention belongs to field of metallurgy, and in particular to the control method of content of vanadium and alloying component in a kind of vanadium iron metallurgical slag.Technical problem to be solved by the invention is to provide the control methods of content of vanadium and alloying component in a kind of vanadium iron metallurgical slag, the following steps are included: being placed in sky ingot mould after reducing agent and fluxing agent are mixed, the vanadium iron metallurgical slag gold for being up to smelting endpoint is cast in above-mentioned ingot mould, stands, is cooling.The method of the present invention can be effectively reduced content of vanadium in slag and effectively control alloying component.
Description
Technical field
The invention belongs to field of metallurgy, and in particular to vanadium undermines the control of alloying component in a kind of vanadium iron smelting process slag
Method processed.
Background technique
As the vanadium micro-alloying intermediate alloy that current steel and iron industry is most widely used, vanadium iron smelt mainly with
Barium oxide is the straight tube furnace one-step method vanadium iron smelting process of raw material and the more phase method smelting ferrovanadium techniques of furnace of tumbling, major technique
Thinking is after being mixed according to a certain percentage using strong reductants such as aluminium or silicon from barium oxide according to different reduction and proportion one
Secondary property is added in smelting furnace in batches and carries out thermal reduction reaction, and the vanadium metal for reacting generation is dissolved with molten metal iron rapidly
Sedimentation, after slag gold is separated and cooled down, obtains the vanadium iron of ingredient qualification.Vanadium iron smelting process needs most asking for solution at present
Topic is to reduce vanadium in slag as far as possible under the premise of guaranteeing vanadium iron stable product quality to lose, to realize efficiently returning for vanadium
It receives.
CN104532105A provides a kind of method using large-scale furnace electro-aluminothermic process production vanadium iron of tumbling, and is smelted using more phases
Match the technology that aluminium combines with ladder, there is the characteristics of easy to operate, saving aluminium consumption, vanadium iron high income.CN106282564A is mentioned
A kind of spray refining method for having supplied smelting ferrovanadium alloy passes through under the premise of guaranteeing single furnace synthesis with aluminium coefficient is 1.05
Part metals aluminium powder needed for furnace smelting is blown into smelting latter stage by spray gun to the smelting of rotation in a manner of refining agent
Spray refining operation is carried out in furnace body, this method can increase impeller in slurry pump interface, promote the reduction of vanadium, be conducive to vanadium in slag
Reduce the raising with efficiency.CN106011601A provides a kind of secondary refining method of smelting ferrovanadium, and this method includes two
Phase electric furnace smelting, the primary molten alloy after slagging tap after the completion of smelting, which pours, casts from hybrid reaction in the ingot mould equipped with refinery,
External refining is carried out, this method can reduce conduction time, reduce lining wear, extends alloy sedimentation, is conducive to alloy yield
Raising.
From the point of view of the prior art disclosed above, either one-step method or the technology of more phase method smelting ferrovanadiums compared with
For maturation, relevant technical measures have been all made of for different process to reduce vanadium in slag and damage, have smelted mentioning for yield to realize
It is high.Generally speaking, more phase methods because in slag in smelting process slag vanadium damage compared in one-step method slag vanadium damage it is low so that this method vanadium yield compared with
One-step method smelting process improves.But from the point of view of smelting latter stage, content of vanadium is not much different in two kinds of technique slags, and
In higher level, it is therefore necessary to for the reduction limit in aluminothermic reduction latter stage, take corresponding measure, reach and promote vanadium in slag
The purpose of reduction.
Summary of the invention
Technical problem to be solved by the invention is to provide the controls of content of vanadium and alloying component in a kind of vanadium iron metallurgical slag
Method.Method includes the following steps: being placed in sky ingot mould after reducing agent and fluxing agent are mixed, it is up to smelting endpoint
Vanadium iron metallurgical slag gold is cast in above-mentioned ingot mould, stands, is cooling.
Specifically, the reducing agent is metal in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component
Aluminium.
Further, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, the reducing agent granularity
≤ 100 mesh.
Further, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, the reducing agent purity
>=99.5%.
Specifically, the fluxing agent is lime in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component
Or at least one of potassium hyperchlorate.
Further, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, the lime it is effective
Ingredient >=98.0%.
Further, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, the high potassium chloride
Effective component >=98.0%.
Wherein, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, the reducing agent and fluxing agent
Weight ratio is 2 ﹕ 1~4.
Wherein, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, 1 ton of molten alloy is corresponding to be added
1.0~5.0kg reducing agent.
Wherein, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, when casting, control 1min casting
5~10 tons of liquid slag gold.
Wherein, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, the time of repose >=
30min。
Further, in above-mentioned vanadium iron metallurgical slag in the control method of content of vanadium and alloying component, the time of repose is
30~60min.
The method of the present invention smelts the status that content of vanadium cannot be effectively reduced in latter stage slag for more phase method vanadium iron smelting processes,
Strong reductant and fluxing agent are added in ingot mould, and strong reductant is sufficiently stirred with slag and alloy in casting process and contacts, reaches
To the quick reduction and effective control of alloying component for promoting vanadium in slag.The method of the present invention has process flow simple, can
Quickly promote the reduction of vanadium, the sedimentation of alloy and effective control of alloying component in slag, is received to realize vanadium iron in slag
The raising of rate and product composition qualification rate.
Specific embodiment
The control method of content of vanadium and alloying component in vanadium iron metallurgical slag of the present invention, includes the following steps:
A, it according to a certain percentage after mixing by reducing agent and fluxing agent, is placed in empty ingot mould to be cast；
B, when electric furnace reaches smelting endpoint, liquid slag gold in electric furnace is poured into according to certain weight time ratio and is equipped with
In the ingot mould of reducing agent and fluxing agent, casting process forms secondary response system；
C, after the completion of casting, a period of time is stood, secondary response is made further to complete reduction and alloy sedimentation；
D, to which ingot mould is transported to cooling zone after the reaction was completed, and furnace, water quenching are torn open after a certain time.
In the method for the present invention step a, the reducing agent is metallic aluminium, and purity >=99.5%, granularity≤100 mesh compares
100 mesh are thin or 100 mesh.
In the method for the present invention step a, there are two effects for the addition of fluxing agent, first is that instantaneous heat quantity is improved, second is that adjustment office
Portion's slag characteristic reduces local slag system fusing point, reduzate agglomeration.The fluxing agent be in lime or potassium hyperchlorate at least
It is a kind of.The lime or potassium hyperchlorate effective component >=98.0%.
In the method for the present invention step a, the reducing agent and fluxing agent weight ratio are 2 ﹕ 1~4.
In the method for the present invention step b, the reducing agent additive amount and molten alloy weight ratio are 1 ton of 1.0~5.0kg ﹕.
It in the method for the present invention step b, will cast on the vanadium iron metallurgical slag Golden Horse after smelting, participate in the slag of reaction
For golden temperature generally on 1800 DEG C, the vanadium iron metallurgical slag gold that conventional smelting operation obtains can meet above-mentioned requirements.
In the method for the present invention step b, casting process is a dynamic reaction process, and secondary response body occurs in casting process
System, that is, include the exothermic reaction of fluxing agent, and liquid slag, alloy and reducing agent react to each other.In order to guarantee casting process system
Thermal loss is as small as possible, while reducing the secondary oxidation of primary alloy in electric furnace in casting process to the greatest extent.It is preferred that control casting
When 1min cast 5~10 tons of liquid slag gold.
In the method for the present invention step c, reduction reaction terminates substantially after the completion of casting, and standing purpose, which is chiefly to facilitate, also to be originated in
Object agglomeration and sedimentation prevent mobile and shake the conjunction for leading to that generated primary alloy and secondary response generate in electric furnace
Gold is involved in the slag of upper layer in cooling procedure and can not settle.It is preferred that time of repose >=30min.More preferable 30~60min.
It is on the one hand because in electric furnace also if adding reducing agent in smelting furnace can not achieve the object of the invention
Former agent addition can only be covered in slag surface, cause smelting process reduction kinetics condition poor, on the other hand be because smelting
The aluminium oxidation by air that the operation easily leads to refining is carried out in electric furnace, not can guarantee the reduction effect i.e. accurate control of alloy aluminium content
System.So the method for the present invention realizes restoring operation using reducing agent and fluxing agent is added in casting process.
In the method for the present invention, due to increasing reduction step in casting, to reduce content of vanadium in slag；Meanwhile also
On the one hand the addition of former agent aluminium promotes the reduction of vanadium, improve alloy grade, the unconsumed aluminium in part enters alloy, improves
Alloy aluminum mass fraction improves the crushing performance of alloy, the addition of reducing agent aluminium is micro- to Silicon In Alloys phosphorus sulphur etc. to about 1.0%
Secondary element has certain interaction, and silicone content is greatly reduced to alloy ingredient stability and is mingled with control favorably, to realize
Effective control to alloying component.
Comparative example
It, will be in electric furnace when content of vanadium is reduced to 1.32% in metallurgical slag in the case where synthesis is 1.02 with aluminium coefficient
About 20 tons of liquid slag gold are dumped into the ingot mould equipped with mixture, and cooling zone is transported to after 30min, and cooling is torn open afterwards for 24 hours
Furnace, water quenching.It is 1.08% that corresponding vanadium iron, which smelts average vanadium content in cold slag, reduces by 0.24 hundred compared with content of vanadium in terminal metallurgical slag
Branch, corresponding alloy V, Al, Si content average value is respectively 50.2%, 0.66% and 0.99%, and A grades of product rates of product are
90.4%.
Embodiment 1
The lime that the metallic aluminium powder and 10kg effective component that by 10kg purity be 99.5%, granularity is 100 mesh are 98.0%
After mixing, evenly laid out in empty ingot mould to be cast, it, will be in electric furnace when content of vanadium is reduced to 1.39% in metallurgical slag
About 20 tons of liquid slag gold are dumped into the ingot mould equipped with mixture in 4min, and secondary response and alloy are carried out in ingot mould
Ingot mould after 30min, is transported to cooling zone by sedimentation, and in tearing furnace, water quenching open afterwards for 24 hours.
Through aforesaid operations, vanadium iron smelts average vanadium content in cold slag and is reduced to 0.83%, respectively compared with terminal smelting and normally
Smelting cold slag content of vanadium reduces by 0.56 and 0.25 percentage point；Alloy V, Al content are respectively 50.4% and 0.73%, more normally
It is about 0.2 and 0.07 percentage point high to smelt heat；Alloy Si content is 0.84%, low about 0.15 percentage of more normal smelting furnace time
Point；A grades of product rates of vanadium iron product are improved to 91.2%.
Embodiment 2
The lime that the metallic aluminium powder and 10kg effective component that by 20kg purity be 99.8%, granularity is 200 mesh are 98.0%
And the potassium hyperchlorate that 10kg effective component is 99.5% is evenly laid out in empty ingot mould to be cast after mixing, works as metallurgical slag
When middle content of vanadium is reduced to 1.32%, about 20 tons of liquid slag gold in electric furnace are dumped into the ingot mould equipped with mixture in 3min
In, and carry out secondary response and alloy sedimentation in ingot mould, after 40min, ingot mould be transported to cooling zone, and in tear open afterwards for 24 hours furnace,
Water quenching.
Through aforesaid operations, vanadium iron smelts average vanadium content in cold slag and is reduced to 0.70%, respectively compared with terminal smelting and normally
Smelting cold slag content of vanadium reduces by 0.62 and 0.38 percentage point；Alloy V, Al content are respectively 50.5% and 0.94%, more normally
It is about 0.2 and 0.28 percentage point high to smelt heat；Alloy Si content is 0.88%, low about 0.11 percentage of more normal smelting furnace time
Point；A grades of product rates of vanadium iron product are improved to 92.1%.
Embodiment 3
The lime that the metallic aluminium powder and 50kg effective component that by 30kg purity be 99.8%, granularity is 200 mesh are 98.0%
And the potassium hyperchlorate that 50kg effective component is 99.5% is evenly laid out in empty ingot mould to be cast after mixing, works as metallurgical slag
When middle content of vanadium is reduced to 1.33%, about 20 tons of liquid slag gold in electric furnace are dumped into the ingot mould equipped with mixture in 3min
In, and carry out secondary response and alloy sedimentation in ingot mould, after 50min, ingot mould be transported to cooling zone, and in tear open afterwards for 24 hours furnace,
Water quenching.
Through aforesaid operations, vanadium iron smelts average vanadium content in cold slag and is reduced to 0.56%, respectively compared with terminal smelting and normally
Smelting cold slag content of vanadium reduces by 0.77 and 0.52 percentage point；Alloy V, Al content are respectively 50.8% and 1.06%, respectively compared with
Normal smelting heat is about 0.6 and 0.07 percentage point high；Alloy Si content is 0.81%, low about 0.17 of more normal smelting furnace time
Percentage point；A grades of product rates of vanadium iron product are improved to 92.9%.
Embodiment 4
The lime that the metallic aluminium powder and 20kg effective component that by 50kg purity be 99.8%, granularity is 200 mesh are 98.0%
And the potassium hyperchlorate that 20kg effective component is 99.5% is evenly laid out in empty ingot mould to be cast after mixing, works as metallurgical slag
When middle content of vanadium is reduced to 1.30%, about 20 tons of liquid slag gold in electric furnace are dumped into the ingot mould equipped with mixture in 3min
In, and carry out secondary response and alloy sedimentation in ingot mould, after 60min, ingot mould be transported to cooling zone, and in tear open afterwards for 24 hours furnace,
Water quenching.
Through aforesaid operations, vanadium iron smelts average vanadium content in cold slag and is reduced to 0.62%, respectively compared with terminal smelting and normally
Smelting cold slag content of vanadium reduces by 0.68 and 0.46 percentage point；Alloy V, Al content are 51.0% and 1.13%, relatively normal to smelt
Heat is about 0.8 and 0.47 percentage point high；Alloy Si content is 0.80, low about 0.08 percentage point of more normal smelting furnace time；Vanadium
A grades of product rates of ferroalloy productor are improved to 94.1%.
Claims (9)
1. the control method of content of vanadium and alloying component in vanadium iron metallurgical slag, it is characterised in that: the following steps are included: by reducing agent
It is placed in sky ingot mould with after fluxing agent mixing, the vanadium iron metallurgical slag gold for being up to smelting endpoint is cast in above-mentioned ingot mould, quiet
It sets, cool down.
2. the control method of content of vanadium and alloying component in vanadium iron metallurgical slag according to claim 1, it is characterised in that: institute
Stating reducing agent is metallic aluminium.
3. the control method of content of vanadium and alloying component in vanadium iron metallurgical slag according to claim 1 or 2, feature exist
In: the reducing agent granularity≤100 mesh；Reducing agent purity >=99.5%.
4. the control method of content of vanadium and alloying component in described in any item vanadium iron metallurgical slags according to claim 1~3, special
Sign is: the fluxing agent is at least one of lime or potassium hyperchlorate.
5. the control method of content of vanadium and alloying component in vanadium iron metallurgical slag according to claim 4, it is characterised in that: institute
State effective component >=98.0% of lime；Effective component >=98.0% of the high potassium chloride.
6. the control method of content of vanadium and alloying component in described in any item vanadium iron metallurgical slags according to claim 1~5, special
Sign is: the reducing agent is 2 ﹕ 1~4 with fluxing agent weight ratio.
7. the control method of content of vanadium and alloying component in described in any item vanadium iron metallurgical slags according to claim 1~6, special
Sign is: 1 ton of molten alloy is corresponding to be added 1.0~5.0kg reducing agent.
8. the control method of content of vanadium and alloying component in described in any item vanadium iron metallurgical slags according to claim 1~7, special
Sign is: when casting, control 1min 5~10 tons of liquid slag gold of casting.
9. the control method of content of vanadium and alloying component in described in any item vanadium iron metallurgical slags according to claim 1~8, special
Sign is: the time of repose >=30min；Further, the time of repose is 30~60min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910721722.9A CN110283998A (en) | 2019-08-06 | 2019-08-06 | The control method of content of vanadium and alloying component in vanadium iron metallurgical slag |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910721722.9A CN110283998A (en) | 2019-08-06 | 2019-08-06 | The control method of content of vanadium and alloying component in vanadium iron metallurgical slag |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110283998A true CN110283998A (en) | 2019-09-27 |
Family
ID=68024895
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910721722.9A Pending CN110283998A (en) | 2019-08-06 | 2019-08-06 | The control method of content of vanadium and alloying component in vanadium iron metallurgical slag |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110283998A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5594453A (en) * | 1979-01-13 | 1980-07-17 | Nippon Steel Corp | Recovering method for vanadium from vanadium-containing hot iron |
| CN101962727A (en) * | 2010-11-12 | 2011-02-02 | 攀钢集团钢铁钒钛股份有限公司 | Method for preparing sigma-phase FeV50 |
| CN102115821A (en) * | 2010-09-13 | 2011-07-06 | 攀钢集团钢铁钒钛股份有限公司 | Method for smelting ferrovanadium |
| CN104141025A (en) * | 2014-08-14 | 2014-11-12 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for casting and dealuminizing ferrovanadium by electro-aluminothermic process |
| CN106011601A (en) * | 2016-07-07 | 2016-10-12 | 攀钢集团攀枝花钢铁研究院有限公司 | External refining method for smelting ferrovanadium |
-
2019
- 2019-08-06 CN CN201910721722.9A patent/CN110283998A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5594453A (en) * | 1979-01-13 | 1980-07-17 | Nippon Steel Corp | Recovering method for vanadium from vanadium-containing hot iron |
| CN102115821A (en) * | 2010-09-13 | 2011-07-06 | 攀钢集团钢铁钒钛股份有限公司 | Method for smelting ferrovanadium |
| CN101962727A (en) * | 2010-11-12 | 2011-02-02 | 攀钢集团钢铁钒钛股份有限公司 | Method for preparing sigma-phase FeV50 |
| CN104141025A (en) * | 2014-08-14 | 2014-11-12 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for casting and dealuminizing ferrovanadium by electro-aluminothermic process |
| CN106011601A (en) * | 2016-07-07 | 2016-10-12 | 攀钢集团攀枝花钢铁研究院有限公司 | External refining method for smelting ferrovanadium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102115821B (en) | Method for smelting ferrovanadium | |
| CN102094097B (en) | Production process for smelting vanadium ferro-alloy by electro-aluminothermic process | |
| CN102199682B (en) | Semisteel steelmaking method | |
| CN105886787B (en) | A kind of method that vanadium is reclaimed from corundum slag containing vanadium | |
| CN102828098A (en) | Method for increasing molten steel finishing point manganese content by adding manganese ore outside furnace | |
| CN109706404B (en) | Titanium-containing carbon steel and production method thereof | |
| CN107099696B (en) | The method for preparing ferro-titanium with wash heat refining based on the reduction of aluminothermy self- propagating gradient | |
| CN106636862A (en) | Technology for smelting super duplex stainless steel for argon oxygen furnace | |
| CN103045929A (en) | Method for producing ferrovanadium by aluminothermic process | |
| CN109825704A (en) | The smelting process of vanadium iron | |
| CN101724751A (en) | Method for smelting high vanadium ferrovanadium | |
| CN102994871A (en) | Method for smelting medium/high-carbon hard-wired steel by vanadium-titanium containing molten iron | |
| CN107964599B (en) | Straight-barrel furnace ferrovanadium smelting method capable of improving vanadium yield | |
| CN106011601A (en) | External refining method for smelting ferrovanadium | |
| CN108950124A (en) | The method for making steel of welding rod steel H08A | |
| CN101591720B (en) | Method for producing aluminum-manganese-iron alloy | |
| CN103741023B (en) | A kind of smelting process of nonmagnetic steel | |
| CN105132621A (en) | Smelting process for steel for low-silicon aluminum steel-free welding wire | |
| CN103205522B (en) | Method for smelting plain carbon steel from semi-steel | |
| CN107447160A (en) | Reduce the smelting process of the residual vanadium of ferrovanadium slag | |
| CN111961791A (en) | Method for producing low-phosphorus steel by smelting high-phosphorus high-titanium molten iron in converter | |
| CN111235349A (en) | Method for producing silicon-vanadium alloy by smelting vanadium-rich slag and silicon-vanadium alloy | |
| CN110283998A (en) | The control method of content of vanadium and alloying component in vanadium iron metallurgical slag | |
| CN105624552B (en) | A kind of V, Ti, Cr, Ni, Cu microalloy high strength steel and its smelting process | |
| CN105671420B (en) | The pure pig iron prepared by a kind of external refining method |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190927 |