CN105349875A - Novel low-cost ferrosilicon with calcium treatment effect and preparation method thereof - Google Patents

Novel low-cost ferrosilicon with calcium treatment effect and preparation method thereof Download PDF

Info

Publication number
CN105349875A
CN105349875A CN201510704009.5A CN201510704009A CN105349875A CN 105349875 A CN105349875 A CN 105349875A CN 201510704009 A CN201510704009 A CN 201510704009A CN 105349875 A CN105349875 A CN 105349875A
Authority
CN
China
Prior art keywords
ferrosilicon
silicon
calcium
cao
cost
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
Application number
CN201510704009.5A
Other languages
Chinese (zh)
Other versions
CN105349875B (en
Inventor
张立峰
刘洋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Science and Technology Beijing USTB
Original Assignee
University of Science and Technology Beijing USTB
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by University of Science and Technology Beijing USTB filed Critical University of Science and Technology Beijing USTB
Priority to CN201510704009.5A priority Critical patent/CN105349875B/en
Publication of CN105349875A publication Critical patent/CN105349875A/en
Application granted granted Critical
Publication of CN105349875B publication Critical patent/CN105349875B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • C22C35/005—Master alloys for iron or steel based on iron, e.g. ferro-alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0006—Adding metallic additives
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

The invention provides novel low-cost ferrosilicon with a calcium treatment effect and a preparation method thereof. The novel low-cost ferrosilicon is mainly prepared from silicon, iron, a small amount of aluminum and calcium and evitable impurities. The total mass of aluminum and calcium accounts for 1-3% of the total mass of the novel low-cost ferrosilicon. According to the preparation method, silica and coke are weighed and added according to the ratio required by design, and a certain amount of CaO is added according to the content of Al2O3 and CaO in coke added to furnace charge so that the mass ratio of Al2O3 to CaO in the furnace charge can be controlled at 1 to 1-1.7. The preparation method is simple in process and low in cost. No strict control requirement for the content of Al in raw materials exists, the level of silica and the level of coke are not strictly limited any more, the viscosity of slag can be reduced by improving the content of CaO in ferrosilicon slag, slag discharge is facilitated, slag-ferrosilicon separation is facilitated to a certain degree, and the yield of the ferrosilicon is improved. The outside-furnace refining procedure of ferrosilicon is omitted, the production cost of the ferrosilicon is saved, and benefits are improved for enterprises.

Description

Novel low-cost ferro-silicon possessing calcium treatment effect and preparation method thereof
Technical field
The invention belongs to the production field of ferrous metallurgy interalloy raw material, relate to the alloying constituent adjustment process that special steel is produced, refer to novel low-cost ferro-silicon possessing calcium treatment effect containing certain C a, Al proportional amount and preparation method thereof particularly.
Background technology
Special steel is the key areas of Iron And Steel Industry, and it is various in style, different properties, and specification of quality is high, applied range, and its kind, Quality and yield are the key criterias weighing national Iron And Steel Industry science and technology and industrialized level.Therefore, low cost production high-cleanness, high and high performance special steel most important.
Special steel, through special chemical composition design, after specific smelting technology, has different use propertieies.Add the silicon of some amount in steel, can significantly improve the intensity of steel, consistency and elasticity, thus when smelting the steel grades such as structure iron, tool steel, spring steel, the ferrosilicon that must add some amount does alloying constituent use.As main special steel reductor and alloy addition, the quality grade of ferro-silicon requires day by day to improve, and require more and more stricter to foreign matter content in ferro-silicon, this also directly affects the economic benefit of the producer simultaneously.For some cord steel, spring steel, the steel grades such as bearing steel and wheel hub steel, require that deoxidation products is the plastic occluded foreignsubstance with good deformability usually, do not allow to separate out A1 2o 3or the aluminum oxide that contains of other fragility is mingled with, particularly for the steel grade not adopting the non-aluminium deoxidation mode of Calcium treatment technique to produce, at this moment in ferrosilicon, the control of content to steel inclusion composition and form of aluminium exerts a decisive influence, use high-quality low AL-Si-Fe alloy at present more for this reason, reduce the rich A1 in steel 2o 3inclusion.
Ferrosilicon many employings silica, carbonaceous reductant and steel cuttings, as raw materials for production, are smelted in electric reduction furnace.In smelting process, except SiO 2outside being reduced, the Al in furnace charge 2o 3, CaO, P 2o 5, FeO is also reduced, make in ferrosilicon containing more impurity.Generally need from the viewpoint of raising feed stock for blast furnace quality and ferrosilicon external refining two at the high-quality low ferro-silicon-aluminium of production at present.The strict feed stock for blast furnace that controls is needed to bring impurity into, particularly Al 2o 3and P 2o 5amount, for reducing the impurity entered in alloy, usually through the mode of ferrosilicon external refining, adopt flux method oxidation refining, in liquid ferrosilicon, add oxidisability slag former, and be blown into air, oxygen or rare gas element simultaneously, oxidation of impurities slagging is removed, improves alloy purity.Al content in ferro-silicon can be reduced to 0.05%, Ca content and be reduced to 0.03%, P content and be down to 0.02% by current high quality silicon iron alloy, but cost is higher, reduces the profit of enterprise.
After the Composition Design of ferro-silicon adds molten steel for it, the character of inclusion has considerable influence, result of study is had to show, the ferro-silicon of the aluminium calcium containing different ratios is added in stainless steel, the character of inclusion also changes thereupon, when aluminium content in the ferrosilicon added is 1.7%, calcium contents be 0.4% or higher calcium contents time, inclusion can enter low melting point liquid phase region (Iron & Steelmaker, Vol.28 (8), 2001,93-101).The ferro-silicon added containing certain calcium contents of gradation before and after sweetening process that U.S. patents discloses of patent No. US7785393B2 is conducive to deoxidation and Control and Inclusion Removal.But, mentioned by this kind of production containing other elemental silicon iron alloys certain is not had.This patent provides a kind of new thinking for the smelting production of ferro-silicon, saves production cost, and to the pure Al in special steel 2o 3inclusion plays modifying function.
Summary of the invention
In order to solve the problem, the object of the present invention is to provide a kind of preparation technology simple, cost is low, namely strict control overflow be there is no to the Al content in raw material, namely silica and coke rank are no longer included to novel low-cost ferro-silicon possessing calcium treatment effect of strict restriction and preparation method thereof.
Technical scheme of the present invention is: the novel low-cost ferro-silicon possessing calcium treatment effect, and this alloy main component comprises silicon, iron and a small amount of aluminium and calcium and inevitable impurity, and the mass percent that aluminium and calcium total amount account for alloy total mass is 1-3%.
Further, the mass ratio of described aluminium and calcium is 1:1.5 ~ 2.5.
Another object of the present invention is to provide the above-mentioned preparation method possessing the novel low-cost ferro-silicon of calcium treatment effect, specifically comprises the following steps:
Silica and coke are taken according to the ratio of design requirements and adds, according to the Al added in furnace charge in coke 2o 3with the content of CaO, add a certain amount of CaO to control Ca content in alloy, make the Al in furnace charge 2o 3control, in 1:1 ~ 1.7, finally to obtain ferro-silicon with the mass ratio of CaO, the aluminium in described ferro-silicon and the mass ratio of calcium contents are 1:1.5 ~ 2.5.
The present invention is according to the Al entering furnace charge 2o 3with the content of CaO, in ferro-silicon production process, add CaO to control Ca content in alloy, make Al 2o 3control in 1:1 ~ 1.7 with the mass ratio of CaO, make in alloy finished product and meet aluminium-calcium-rate scope in 1:1.5 ~ 2.5.And improving CaO content in ferrosilicon slag can make cinder viscosity reduce, and is conducive to deslagging, be conducive to slag gold to a certain extent and be separated, put forward heavy alloyed recovery rate.Controlling well in furnace charge after other impurity components, the external refining operation of ferrosilicon can saved, saving the production cost of ferro-silicon, improving the performance of enterprises.
The chemical reaction of ferrosilicon production process:
SiO 2+2C=Si+2CO
Fe+Si=FeSi
CaO+C=Ca+CO
Al 2O 3+3C=2Al+3CO
Alloy adds the chemical reaction of molten steel:
2Si+[O]=SiO 2
2xAl+yCa+(3x+y)[O]=xAl 2O 3-yCaO
After this novel silicon iron alloy adds the molten steel of non-aluminium deoxidation, Ca and the Al in alloy fully reacts, and rationally utilizes, and improves the recovery rate of Ca, the disadvantageous effect that the Al that reduction alloy is brought into produces inclusion in molten steel, does not produce pure Al 2o 3, reach the effect of similar Calcium treatment, play the condition changing steel inclusion, reduce the content of steel inclusion, improve the effect of the mechanical property of steel.The novel silicon iron alloy optimized is no longer strictly by the restriction of material condition, and save the external refining cost producing high-purity low AL-Si-Fe alloy, the scavenging agent can also produced as high purity steel, reaches better metallurgical effect simultaneously.
The invention has the beneficial effects as follows: owing to adopting technique scheme, the method technique is simple, cost is low, namely strict control overflow be there is no to the Al content in raw material, namely strict restriction is no longer included to silica and coke rank, cinder viscosity can be made to reduce by improving CaO content in ferrosilicon slag, being conducive to deslagging, be conducive to slag gold to be to a certain extent separated, put forward heavy alloyed recovery rate.Controlling well in furnace charge after other impurity components, the external refining operation of ferrosilicon can saved, saving the production cost of ferro-silicon, improving the performance of enterprises.In addition, for the special steel adopting silicon manganese dioxidation agent to produce, usually add high purity ferrosilicon alloy at refining process at present and carry out molten steel component adjustment, cost is higher.And adopt the novel alloy described in this patent, can, in the process of alloy deoxidation, calcium and aluminium in alloy fully be combined, by the content of calcium and aluminium in allotment alloy, make Al in the inclusion of molten steel 2o 3control at Al with the content of CaO 2o 3-CaO and Al 2o 3between-3CaO, reach the desired result of similar Calcium treatment.Be conducive to floating and remove, and there is lower fusing point and higher deformation performance, reduce the harm that inclusion produces finished product, cost-saving, increase the benefit.
Embodiment
Below in conjunction with specific embodiment, technical scheme of the present invention is described further.
In the industrial production, the impurity of ferro-silicon is brought into primarily of silica and carbonaceous reductant, for this novel silicon iron alloy, to Al in raw material 2o 3the requirement of the severe specifications upper limit is not had with CaO content, only need to MgO, P 2o 5content controls, particularly P 2o 5content can not be greater than 0.03%, and the content improving CaO makes its ratio meet aluminium-calcium-rate 1:1.5 ~ 2.5 in the ferro-silicon of reduction, makes yellow phosphate be more prone to realize.
Ferrosilicon takes line production to smelt in open type or semienclosed reduction furnace, in whole smelting process, electrode is inserted in furnace charge deeply and quietly, the furnace charge of mixing evenly sinks, keep the certain altitude of charge level in stove, when alloy in stove is accumulate to a certain degree, open stove eye and release.It is belong to produce without slag that ferrosilicon is produced, but can produce a small amount of slag in actual production, and because slag melting is high, viscosity is large, not only can increase power consumption, also can cause furnace bottom rising, worsens the working of a furnace.In addition, density and the ferrosilicon of slag are close, are not easy to remove, and easily make alloy slag inclusion, according to Al 2o 3-SiO 2-CaO phasor is known, and improve CaO content in ferrosilicon slag and cinder viscosity can be made to reduce, be conducive to deslagging, therefore, in the production process of novel silicon iron alloy, the furnace charge that enters of high CaO content adds, and is also conducive to slag gold to a certain extent and is separated.
The present invention possesses the novel low-cost ferro-silicon of calcium treatment effect, this alloy main component comprises silicon, iron and a small amount of aluminium and calcium and inevitable impurity, the mass percent that aluminium and calcium total amount account for alloy total mass is 1-3%, and the mass ratio of described aluminium and calcium is 1:1.5 ~ 2.5.
Another object of the present invention is to provide the above-mentioned preparation method possessing the novel low-cost ferro-silicon of calcium treatment effect, specifically comprises the following steps:
Silica and coke are taken according to the ratio of design requirements and adds, according to the Al added in furnace charge in coke 2o 3with the content of CaO, add a certain amount of CaO to control Ca content in alloy, make the Al in furnace charge 2o 3control, in 1:1 ~ 1.7, finally to obtain ferro-silicon with the mass ratio of CaO, the aluminium in described ferro-silicon and the mass ratio of calcium contents are 1:1.5 ~ 2.5.
Embodiment 1:
This alloy main component comprises silicon, iron and a small amount of aluminium and calcium and inevitable impurity, and the mass percent that aluminium and calcium total amount account for alloy total mass is 2%, and the mass ratio of described aluminium and calcium is 1:1.5.
Silica and coke are taken according to the ratio of design requirements and adds, according to the Al added in furnace charge in coke 2o 3with the content of CaO, add a certain amount of CaO to control Ca content in alloy, make the Al in furnace charge 2o 3control, at 1:1, finally to obtain ferro-silicon with the mass ratio of CaO, the aluminium in described ferro-silicon and the mass ratio of calcium contents are 1:1.5.
Embodiment 2:
This alloy main component comprises silicon, iron and a small amount of aluminium and calcium and inevitable impurity, and the mass percent that aluminium and calcium total amount account for alloy total mass is 1%, and the mass ratio of described aluminium and calcium is 1:2.
Silica and coke are taken according to the ratio of design requirements and adds, according to the Al added in furnace charge in coke 2o 3with the content of CaO, add a certain amount of CaO to control Ca content in alloy, make the Al in furnace charge 2o 3control, at 1:1.2, finally to obtain ferro-silicon with the mass ratio of CaO, the aluminium in described ferro-silicon and the mass ratio of calcium contents are 1:2.
Embodiment 3:
This alloy main component comprises silicon, iron and a small amount of aluminium and calcium and inevitable impurity, and the mass percent that aluminium and calcium total amount account for alloy total mass is 3%, and the mass ratio of described aluminium and calcium is 1:2.5.
Silica and coke are taken according to the ratio of design requirements and adds, according to the Al added in furnace charge in coke 2o 3with the content of CaO, add a certain amount of CaO to control Ca content in alloy, make the Al in furnace charge 2o 3control, at 1:1.7, finally to obtain ferro-silicon with the mass ratio of CaO, the aluminium in described ferro-silicon and the mass ratio of calcium contents are 1:2.5.

Claims (3)

1. possess the novel low-cost ferro-silicon of calcium treatment effect, this alloy main component comprises silicon, iron and a small amount of aluminium and calcium and inevitable impurity, and it is characterized in that, the mass percent that aluminium and calcium total amount account for alloy total mass is 1-3%.
2. ferro-silicon according to claim 1, is characterized in that, the mass ratio of described aluminium and calcium is 1:1.5 ~ 2.5.
3. prepare a ferro-silicon as claimed in claim 1 or 2, it is characterized in that, specifically comprise the following steps: silica and coke are taken according to the ratio of design requirements and adds, according to the Al added in furnace charge in coke 2o 3with the content of CaO, add a certain amount of CaO to control Ca content in alloy, make the Al in furnace charge 2o 3control, in 1:1 ~ 1.7, finally to obtain ferro-silicon with the mass ratio of CaO, the aluminium in described ferro-silicon and the mass ratio of calcium contents are 1:1.5 ~ 2.5.
CN201510704009.5A 2015-10-27 2015-10-27 Possesses low-cost silicon ferroalloy of calcium treatment effect and preparation method thereof Active CN105349875B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510704009.5A CN105349875B (en) 2015-10-27 2015-10-27 Possesses low-cost silicon ferroalloy of calcium treatment effect and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510704009.5A CN105349875B (en) 2015-10-27 2015-10-27 Possesses low-cost silicon ferroalloy of calcium treatment effect and preparation method thereof

Publications (2)

Publication Number Publication Date
CN105349875A true CN105349875A (en) 2016-02-24
CN105349875B CN105349875B (en) 2018-02-27

Family

ID=55325934

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510704009.5A Active CN105349875B (en) 2015-10-27 2015-10-27 Possesses low-cost silicon ferroalloy of calcium treatment effect and preparation method thereof

Country Status (1)

Country Link
CN (1) CN105349875B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106011373A (en) * 2016-06-17 2016-10-12 首钢总公司 Production method for performing calcium treatment on molten steel by using residual calcium in antaciron
CN106119461A (en) * 2016-06-21 2016-11-16 首钢京唐钢铁联合有限责任公司 Method for calcium treatment of molten steel
CN108642239A (en) * 2018-05-14 2018-10-12 北京科技大学 The method for carrying out molten steel alloying with silicon and Calcium treatment using calcium ferro-silicon alloy containing metal
CN110982984A (en) * 2019-12-05 2020-04-10 中天钢铁集团有限公司 Production process of Al deoxidized non-calcium treated steel
CN113981172A (en) * 2021-10-29 2022-01-28 宁夏金圆化工有限公司 Vanadium reduction method for producing high-purity silicon iron
CN118006952A (en) * 2024-02-04 2024-05-10 张掖市巨龙铁合金有限公司 Method for producing ferrosilicon alloy by utilizing oxide scale

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104342595A (en) * 2013-07-30 2015-02-11 内蒙古大唐国际再生资源开发有限公司 Production technology of ferrosilicon alloy

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104342595A (en) * 2013-07-30 2015-02-11 内蒙古大唐国际再生资源开发有限公司 Production technology of ferrosilicon alloy

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
F.MARGARIDO ET AL.: "Microstructure vs.casting processes in the Fe-Si-Ca-Al system", 《MATERIALS SCIENCE AND ENGINEERING》 *
FERNANDA MARGARIDO ET AL.: "CAALSIFER：A Quaternary Fe-Al-Si-Ca Phase Isotypic with α-Leboite(Fe1-xSi2)", 《MATERIALS SCIENCE AND ENGINEERING》 *
陈冰等: "低铝硅铁的生产", 《铁合金》 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106011373A (en) * 2016-06-17 2016-10-12 首钢总公司 Production method for performing calcium treatment on molten steel by using residual calcium in antaciron
CN106119461A (en) * 2016-06-21 2016-11-16 首钢京唐钢铁联合有限责任公司 Method for calcium treatment of molten steel
CN106119461B (en) * 2016-06-21 2018-07-27 首钢京唐钢铁联合有限责任公司 Method for calcium treatment of molten steel
CN108642239A (en) * 2018-05-14 2018-10-12 北京科技大学 The method for carrying out molten steel alloying with silicon and Calcium treatment using calcium ferro-silicon alloy containing metal
CN110982984A (en) * 2019-12-05 2020-04-10 中天钢铁集团有限公司 Production process of Al deoxidized non-calcium treated steel
CN113981172A (en) * 2021-10-29 2022-01-28 宁夏金圆化工有限公司 Vanadium reduction method for producing high-purity silicon iron
CN118006952A (en) * 2024-02-04 2024-05-10 张掖市巨龙铁合金有限公司 Method for producing ferrosilicon alloy by utilizing oxide scale

Also Published As

Publication number Publication date
CN105349875B (en) 2018-02-27

Similar Documents

Publication Publication Date Title
CN105349875A (en) Novel low-cost ferrosilicon with calcium treatment effect and preparation method thereof
CN102586685B (en) Smelting process of steel for high-titanium alloy welding wire
CN103469050A (en) Aluminum-containing cold forging steel smelting process
CN102206730B (en) Method for controlling oxygen and reducing nitrogen in molten steel
CN103882181B (en) Manganese-containing steel alloying process
CN102329917B (en) Production method of clean steel
CN102827997A (en) Calcium carbide ferro-aluminium alloy used for smelting steel, and preparation method thereof
CN100535152C (en) Method for smelting stainless steel oxidizing slag by using argon oxygen furnace
CN101220413A (en) Technique for smelting ferroferrite with sponge iron
CN110541114A (en) smelting method of high-nitrogen high-sulfur low-aluminum steel
CN105886765A (en) Method for producing ferrosilicon
CN107012285A (en) A kind of inexpensive deoxidization technique of converter mild steel tapping process
CN112626312A (en) Low-carbon aluminum killed steel Al for reducing RH single process2O3Method of inclusion
CN102477472A (en) Mild steel desulfurization refining method
CN102181755B (en) Low calcium-aluminum-manganese-iron alloy and preparation method thereof
CN102839292A (en) Aluminum iron alloy with ultra-low carbon, ultra-low titanium and high silicon contents for deoxidizing aluminum silicon killed steel and manufacturing method of aluminum iron alloy
CN102102138B (en) Method for solving copper segregation in steel
CN112708728B (en) Method for improving plasticity of non-metallic inclusion in aluminum deoxidized steel/aluminum-containing steel
CN112481550B (en) Smelting process of lanthanum-cerium-rare earth alloy die steel
CN109972062B (en) High-purity large electroslag ingot and production method thereof
CN108715972A (en) A kind of low-phosphorous silicon iron product and its smelting process
CN114480777A (en) Method for realizing 82B high-carbon tapping of converter through double-slag method
CN107828937A (en) The control method of sulphur in a kind of high-sulfur steel smelting process
CN102766801A (en) Rare earth Al-Ca-Fe alloy for rare earth micro-treated steel and preparation method thereof
CN111304523A (en) Production process of low-aluminum ferrosilicon

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant