CN1724341A - Process for producing super high pured phosphoric acid - Google Patents
Process for producing super high pured phosphoric acid Download PDFInfo
- Publication number
- CN1724341A CN1724341A CN 200510003114 CN200510003114A CN1724341A CN 1724341 A CN1724341 A CN 1724341A CN 200510003114 CN200510003114 CN 200510003114 CN 200510003114 A CN200510003114 A CN 200510003114A CN 1724341 A CN1724341 A CN 1724341A
- Authority
- CN
- China
- Prior art keywords
- phosphoric acid
- pured
- super high
- production method
- acid according
- 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
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 title claims abstract description 80
- 229910000147 aluminium phosphate Inorganic materials 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title description 17
- 238000004519 manufacturing process Methods 0.000 claims abstract description 25
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 11
- OBSZRRSYVTXPNB-UHFFFAOYSA-N tetraphosphorus Chemical compound P12P3P1P32 OBSZRRSYVTXPNB-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000010521 absorption reaction Methods 0.000 claims description 23
- 238000000746 purification Methods 0.000 claims description 13
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 12
- 238000001914 filtration Methods 0.000 claims description 10
- 239000000243 solution Substances 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 8
- 239000012670 alkaline solution Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 6
- 239000002253 acid Substances 0.000 claims description 6
- -1 polyethylene Polymers 0.000 claims description 6
- 239000002994 raw material Substances 0.000 claims description 6
- 238000005406 washing Methods 0.000 claims description 6
- 238000004806 packaging method and process Methods 0.000 claims description 5
- 150000004965 peroxy acids Chemical class 0.000 claims description 4
- 229920000573 polyethylene Polymers 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 239000001117 sulphuric acid Substances 0.000 claims description 4
- 235000011149 sulphuric acid Nutrition 0.000 claims description 4
- 239000004698 Polyethylene Substances 0.000 claims description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 3
- 238000012856 packing Methods 0.000 claims 1
- 238000004377 microelectronic Methods 0.000 abstract description 4
- 230000002194 synthesizing effect Effects 0.000 abstract 1
- 235000011007 phosphoric acid Nutrition 0.000 description 30
- 239000000047 product Substances 0.000 description 19
- 230000009102 absorption Effects 0.000 description 18
- 238000005516 engineering process Methods 0.000 description 7
- 238000001514 detection method Methods 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 239000003513 alkali Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 229910052787 antimony Inorganic materials 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 229910052793 cadmium Inorganic materials 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 238000001095 inductively coupled plasma mass spectrometry Methods 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 150000003016 phosphoric acids Chemical class 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000003570 air Substances 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 206010025482 malaise Diseases 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000002000 scavenging effect Effects 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
Landscapes
- Glass Compositions (AREA)
Abstract
A process for preparing ultrahigh-purity phosphoric acid includes such steps as burning the electronic-class yellow or red phosphorus, absorbing, and synthesizing to obtain said product used in microelectronic industry. Its advantages are ultrahigh purity and low cost.
Description
Technical field: the present invention relates to the production method of phosphoric acid, especially for the production method of the super high pured phosphoric acid of microelectronics industry.
Background technology: super high pured phosphoric acid is used for the production of unicircuit manufacturing and TFT-LCD liquid-crystal display in a large number.Purity requirement SO
4 -2≤ 10ppm, NO
3 -2≤ 5Pppm, Cl≤0.5ppm, Al≤50ppb, As20ppb, Sb≤200ppb, Ba≤20ppb, Cr≤50ppb, Cd≤50ppb, Ca≤50ppb, Co≤50ppb, Cu≤50ppb, Au≤20ppb, Fe≤100ppb, Pb≤50ppb, Li≤50ppb, Mg≤50ppb, Mn≤30ppb, Ni≤50ppb, K≤100ppb, Ag≤30ppb, Na≤200ppb, Sr≤50ppb, Zn≤20ppb.At present, also do not produce the production technique of super high pured phosphoric acid at home, more is the production technique of food grade phosphoric acid, the method of producing the food grade high-purity phosphoric acid is as wet phosphoric acid purifying method for refining, the thermal phosphoric acid method of purification, crystallization legal system pure phosphoric acid, electrolytic cleaning method and ion-exchange and electroosmotic drainage etc., above method is a raw material with industrial thermal phosphoric acid or phosphoric acid by wet process all, and the phosphoric acid quality index of making is: SO
4 -2≤ 50ppm, Fe≤20000pp, As≤100ppb, Pb≤3000ppb, Cu≤100ppb, Cr≤500ppb, Ni≤200ppb.So all can not reach the requirement of the requirement of microelectronic industry, particularly super large-scale integration and TFT-LCD; Also useful abroad phosphoric acid prepares the technology of super high pured phosphoric acid, but the method that all adopts multiple working procedure to purify is carried out, be not that direct production obtains, such problem is: production technique is too much, product cost increases, the product costliness, and quality is difficult to be effectively controlled.
Summary of the invention: the objective of the invention is, a kind of production method of super high pured phosphoric acid is provided, especially for the production method of the super high pured phosphoric acid of microelectronics industry, directly just with the phosphoric acid preparation, technology is simple, easy to operate, quality is convenient to control for this method, low finished product cost; The high-content of the super high pured phosphoric acid individual event nonmetallic impurity that it makes is not more than 10ppm, and the high-content of individual event metallic impurity is not more than 100ppb, and quality meets the quality requirements of manufacturing processedes such as super large-scale integration and TFT-LCD.
The present invention is achieved in that its adopts electronic grade yellow phosphorus or red phosphorus as raw material, and electronic grade yellow phosphorus or red phosphorus are sent into roasting kiln, feeds simultaneously through chemical treatment and the filtering excess air of strainer, it is fully burnt, with the gaseous state P that produces
2O
5Feed in the absorption tower, in the absorption tower, adopt pure water absorptions that circulate, after phosphoric acid concentration that circulation absorbs reaches 85.0%-87.0%, send into pan tank, be not more than under the environment purification that thousand grades, part are not more than hundred grades in integral body and filter, detect, pack.
Its purity of electronic grade yellow phosphorus that is adopted or red phosphorus is not less than 99.999% (5N).The material of packaging vessel, equipment and pipeline adopts pure polyethylene, polypropylene, tetrafluoroethylene or silica glass.The absorption tower makes of pure quartz glass.The air that feeds filters through the washing of peracid solutions and alkaline solution and with micron filter.The absorption water that is adopted reaches the one-level or the secondary standard of GB6682-92 standard code.Circulatory pool, filtration and can are operated under hundred grades of environment purifications.The acid solution that rinse air is used is a sulphuric acid soln, and alkaline solution is sodium hydroxide or potassium hydroxide solution.Micron filter is: the strainer of 0.1-1 micron.Technique scheme is because raw material adopts electronic grade yellow phosphorus or red phosphorus, high-purity water and air, the strict again control of process.So good product quality, the good stability produced and realize product up-gradation are easily easily accomplished scale production.This technology has reduced many scavenging process with to be raw material with industrial phosphoric acid by wet process or thermal phosphoric acid compare by chemistry and physical method purification process, has solved the difficult problem that big unwell filter of strong phosphoric acid viscosity and phosphoric acid can not rectification and purification; The price that technology of the present invention is simple, easy to operate, quality is convenient to control, the finished product price is significantly less than external like product begun suitability for industrialized production at present, solved China for a long time this product want the situation of dependence on import always.
Creativeness of the present invention is: the present invention is a technology of directly just producing the finished product; What the contriver was a large amount of experimental results show that: if raw material is selected the following product that then can not direct production goes out to meet the demands of 99.999% (5N) for use; If it washs then airborne impurity and can have a strong impact on quality product without acid base pair; Because this product has corrodibility, so if the material that equipment, pipeline, pump and packaging vessel material are used not according to selected use then can cause secondary pollution to influence final product quality simultaneously! For determining of specific targets, the contriver obtains by experiment: be lower than selected technical parameter and then be difficult to produce qualified product, if be higher than selected technical parameter, although it is can produce qualified product, also unreasonable from calculating economically.
Embodiment:
Embodiments of the invention 1: with 1000 kilograms of electronic grade yellow phosphorus, purity is the 6N level: 99.9999% (As≤60ppb wherein, S≤100ppb, Fe≤80ppb, Cu≤60ppb, Cr≤60ppb, Mn≤60ppb, Zn≤50ppb) with being pumped into roasting kiln, feed simultaneously through acid-alkali washing (with sulfuric acid and sodium hydroxide solution wash, acid base concentration is not special requires) and the filtering excess air of commercially available 0.1 micron filter, yellow phosphorus is fully burnt, the gaseous state P of generation
2O
5In the absorption tower that makes of silica glass, absorb (circulatory pool must be indoor at hundred-grade super-clean) with the one-level pure water circulation that reaches the GB6682-92 standard code, after phosphoric acid concentration reaches 85.0%-87.0%, pump into pan tank, at whole thousand grades, under the environment purification of local laminar flow, carry out can, product virgin pp container package can get 3510 kilograms of super high pured phosphoric acids.Product detects the wherein content of S with ICP-MS detection Cl, Al, Sb, As, Ba, B, Cd, Ca, Cr, Co, Cu, Au, Fe, Pb, Li, Mg, Mn, Ni, K, Si, Te, Zn content wherein with CS-444.The result is as follows: NO3≤4ppm, SO4≤6ppb, Fe≤37ppb, Cu≤21ppb, Cr≤19ppb, Mn≤32ppb, Zn≤11, Al≤34ppb, Au≤9ppb, As≤19ppb, Ba≤33ppb, Ca≤100ppb, Co≤27ppb, Pb≤41, Mg≤28ppb, Ni≤30ppb, Li≤29ppb, Sb≤65ppb, Cd≤48ppb, k≤147ppb, Na≤160ppb, Sr≤5ppb, Ti≤40ppb.
Embodiments of the invention 2: (purity is the 5N level: 99.999% with 100 kilograms of electronic grade red phosphorus, As≤150ppb wherein, S≤200ppb, Fe≤500ppb, Cu≤200ppb, Cr≤150ppb, Mn≤150ppb, Zn≤50ppb) send into roasting kiln feeds then through chemical absorption and the commercially available filtering excess air of 1 micron filter, red phosphorus is fully burnt, the gaseous state P of generation
2O
5In the absorption tower, absorb (circulatory pool must be indoor at hundred-grade super-clean) with the secondary pure water circulation that reaches the GB6682-92 standard code, after phosphoric acid concentration reaches 85.0%-87.0%, pump into pan tank, at whole thousand grades, carry out can under the environment purification of local laminar flow, finished product is packed with pure polythene container, can get 347 kilograms of super high pured phosphoric acids.Its quality product is as follows: product detects the wherein content of S with ICP-MS detection Cl, Al, Sb, As, Ba, B, Cd, Ca, Cr, Co, Cu, Au, Fe, Pb, Li, Mg, Mn, Ni, K, Si, Te, Zn content wherein with CS-444.The result is as follows: NO3≤5ppm, SO4≤12ppm, Fe≤500ppb, Cu≤50ppb, Cr≤100ppb, Mn≤100ppb, Zn≤50, Al≤140ppb, Au≤45ppb, As≤89ppb, Ba≤97ppb, Ca≤600ppb, Co≤46ppb, Pb≤174ppb, Mg≤138ppb, Ni≤140ppb, Li≤29ppb, Sb≤65ppb, Cd≤98ppb, k≤347ppb, Na≤560ppb, Sr≤100ppb, Ti≤122pp.
Embodiments of the invention 3: with purity is that 99.999% electronic grade yellow phosphorus is sent into roasting kiln for 1000 kilograms, feeds simultaneously through peracid solutions and alkaline solution washing and with 0.The filtering excess air of 1 micron filter is fully burnt it, with the gaseous state P that produces
2O
5Feed in the absorption tower, adopt pure water absorptions that circulate in the absorption tower, the phosphoric acid concentration that absorbs when circulation reaches 85.0% and just can send into pan tank, is not more than under the environment purification that thousand grades, part are not more than hundred grades in integral body to filter, detection, pack; The material of packaging vessel, equipment and pipeline adopts pure polyethylene, polypropylene, tetrafluoroethylene or silica glass in the present embodiment; The absorption tower makes of pure quartz glass.The absorption water that is adopted reaches the primary standard of GB6682-92 standard code.Circulatory pool, filtration and can are operated under hundred grades of environment purifications.The acid solution that rinse air is used is a sulphuric acid soln, and alkaline solution is a sodium hydroxide solution.The order of washing is influence not, can first pickling after alkali cleaning, also can be conversely.Micron filter is the commercially available prod.The equipment of all uses, material all can be bought on market and obtain in this technology.
Embodiments of the invention 4: with purity is that 99.99999% electronic grade red phosphorus is sent into roasting kiln for 10000 kilograms, feeds simultaneously through chemical treatment and the filtering excess air of strainer, it is fully burnt, with the gaseous state P that produces
2O
5Feed in the absorption tower, in the absorption tower, adopt pure water absorptions that circulate, after phosphoric acid concentration that circulation absorbs reaches 87.0%, send into pan tank, be not more than under the environment purification that thousand grades, part are not more than hundred grades in integral body and filter, detect, pack.The material adopting quartz glass of absorption tower, packaging vessel, equipment and pipeline is made.The air that feeds filters through the washing of peracid solutions and alkaline solution and with micron filter.The absorption water that is adopted reaches the secondary standard of GB6682-92 standard code.Circulatory pool, filtration and can are operated under hundred grades of environment purifications.The acid solution that rinse air is used is a sulphuric acid soln, and alkaline solution is a potassium hydroxide solution.Micron filter is: 0.5 micron strainer.
Claims (9)
1, a kind of production method of super high pured phosphoric acid, it is characterized in that: it adopts electronic grade yellow phosphorus or red phosphorus as raw material, electronic grade yellow phosphorus or red phosphorus are sent into roasting kiln, feed simultaneously through chemical treatment and the filtering excess air of strainer, it is fully burnt, the gaseous state P2O5 that produces is fed in the absorption tower, in the absorption tower, adopt the pure water absorption that circulates, after phosphoric acid concentration that circulation absorbs reaches 85.0%-87.0%, send into pan tank, be not more than under the environment purification that thousand grades, part are not more than hundred grades in integral body filter, detect, packing.
2, the production method of super high pured phosphoric acid according to claim 1 is characterized in that: its purity of electronic grade yellow phosphorus that is adopted or red phosphorus is not less than 99.999%.
3, the production method of super high pured phosphoric acid according to claim 1 is characterized in that: the material of packaging vessel, equipment and pipeline adopts pure polyethylene, polypropylene, tetrafluoroethylene or silica glass.
4, the production method of super high pured phosphoric acid according to claim 1 is characterized in that: the absorption tower makes of pure quartz glass.
5, the production method of super high pured phosphoric acid according to claim 1 is characterized in that: the air of feeding filters through the washing of peracid solutions and alkaline solution and with micron filter.
6, the production method of super high pured phosphoric acid according to claim 1 is characterized in that: the absorption water that is adopted reaches the one-level or the secondary standard of GB6682-92 standard code.
7, the production method of super high pured phosphoric acid according to claim 1 is characterized in that: circulatory pool, filtration and can are operated under hundred grades of environment purifications.
8, the production method of super high pured phosphoric acid according to claim 5 is characterized in that: the acid solution that rinse air is used is a sulphuric acid soln, and alkaline solution is sodium hydroxide or potassium hydroxide solution.
9, the production method of super high pured phosphoric acid according to claim 5, it is characterized in that: micron filter is: the strainer of 0.1-1 micron.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200510003114 CN1724341A (en) | 2005-06-23 | 2005-06-23 | Process for producing super high pured phosphoric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200510003114 CN1724341A (en) | 2005-06-23 | 2005-06-23 | Process for producing super high pured phosphoric acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1724341A true CN1724341A (en) | 2006-01-25 |
Family
ID=35923998
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200510003114 Pending CN1724341A (en) | 2005-06-23 | 2005-06-23 | Process for producing super high pured phosphoric acid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1724341A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102336398A (en) * | 2010-07-09 | 2012-02-01 | 日本化学工业株式会社 | Method for production of high purity elemental phosphorus and method for production of high purity phosphoric acid |
| CN101531353B (en) * | 2009-04-28 | 2013-09-25 | 云南省化工研究院 | Method for directly preparing electronic grade phosphoric acid by yellow phosphorus |
| CN103553010A (en) * | 2013-11-11 | 2014-02-05 | 云南省化工研究院 | Production process of high-purity phosphorus pentoxide |
| CN109052352A (en) * | 2018-10-10 | 2018-12-21 | 湖北兴福电子材料有限公司 | A kind of method of industrial yellow phosphorus production electron-level phosphoric acid |
-
2005
- 2005-06-23 CN CN 200510003114 patent/CN1724341A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101531353B (en) * | 2009-04-28 | 2013-09-25 | 云南省化工研究院 | Method for directly preparing electronic grade phosphoric acid by yellow phosphorus |
| CN102336398A (en) * | 2010-07-09 | 2012-02-01 | 日本化学工业株式会社 | Method for production of high purity elemental phosphorus and method for production of high purity phosphoric acid |
| CN103553010A (en) * | 2013-11-11 | 2014-02-05 | 云南省化工研究院 | Production process of high-purity phosphorus pentoxide |
| CN103553010B (en) * | 2013-11-11 | 2015-09-09 | 云南省化工研究院 | A kind of production technique of high purity Vanadium Pentoxide in FLAKES |
| CN109052352A (en) * | 2018-10-10 | 2018-12-21 | 湖北兴福电子材料有限公司 | A kind of method of industrial yellow phosphorus production electron-level phosphoric acid |
| CN109052352B (en) * | 2018-10-10 | 2021-09-07 | 湖北兴福电子材料有限公司 | Method for producing electronic grade phosphoric acid from industrial yellow phosphorus |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10106426B2 (en) | Method for the separation of metal ions that are divalent or higher from strong acids or highly acidic media | |
| CN103991882B (en) | The fluorine in phosphoric acid by wet process liquid phase is utilized to prepare the method for Potassium monofluoride | |
| CN103303886B (en) | Novel method for producing industrial phosphoric acid by purification with wet process phosphoric acid | |
| CN102320585B (en) | Method for direct production of industrial-grade ammonium biphosphate by wet-process phosphoric acid | |
| CN101531353B (en) | Method for directly preparing electronic grade phosphoric acid by yellow phosphorus | |
| CN1724341A (en) | Process for producing super high pured phosphoric acid | |
| CN101597040A (en) | A kind of method of using producing food grade phosphoric acid with refined wet phosphoric acid and products thereof | |
| CN101823704B (en) | Method for continuously synthesizing phosphorous acid | |
| CN101638260B (en) | Method for preparing polymeric aluminum sulfate silicate by recycling activated clay industrial wastewater | |
| CN1312040C (en) | Purification production technique for producing high pure and high clear lithium hydroxide from lithium hydroxide in industrial grade | |
| CN103435376A (en) | Method and apparatus used for preparing ammonium phosphate fertilizer from phosphoric acid sediment | |
| CN111960446B (en) | Method for continuously producing high-purity lithium carbonate | |
| CN102107859B (en) | Method for purifying yellow phosphorus by using methods of activated carbon adsorption together with dilute nitric acid rinsing | |
| CN111392704A (en) | Preparation method of optical-grade aluminum metaphosphate | |
| CN107758716A (en) | A kind of utilize smelts the method that fluorine-containing spent acid prepares ice crystal | |
| CN207121495U (en) | A kind of reuse means of wastewater from TiO2 factory | |
| CN107364878A (en) | A kind of high-purity soda ash of low calcium and its production method by the production of sodium sulfate type ore deposit halogen | |
| CN109319795A (en) | The method of recycling purification silicon powder production silica solution from organosilicon slag | |
| CN102677076B (en) | Method for removal of silicon impurities in silicon steel pickling waste liquor without dissolving process | |
| CN102225770B (en) | The method of wet method Effect of Catalysis In Petrochemistry agent dedicated water glass | |
| CN103771367B (en) | A kind of stirred crystallization produces the method for electron-level phosphoric acid | |
| CN105329974B (en) | A kind of method that fluorine is reclaimed from fluoride waste | |
| CN211813468U (en) | Calcium nitrate apparatus for producing | |
| CN107381578B (en) | The method that defluorination residues purification prepares prodan | |
| CN220578932U (en) | Refined phosphoric acid dearsenification device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| ASS | Succession or assignment of patent right |
Owner name: GUIZHOU WEIDUN CRYSTAL ELECTRON MATERIAL CO., LTD Free format text: FORMER OWNER: WU ZHANPING Effective date: 20060630 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20060630 Address after: 550014 new material industrial park, Baiyun North Road, Baiyun District, Guizhou, Guiyang Applicant after: GUIZHOU WYLTON JINLIN ELECTRONIC MATERIALS Co., Ltd. Address before: 550058 material technology innovation base of Baiyun North Road, Baiyun District, Guizhou, Guiyang Applicant before: Wu Zhanping |
|
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |