CN102701260A - Spray pyrolysis method for aid-containing rare earth chloride solution - Google Patents
Spray pyrolysis method for aid-containing rare earth chloride solution Download PDFInfo
- Publication number
- CN102701260A CN102701260A CN2012101902973A CN201210190297A CN102701260A CN 102701260 A CN102701260 A CN 102701260A CN 2012101902973 A CN2012101902973 A CN 2012101902973A CN 201210190297 A CN201210190297 A CN 201210190297A CN 102701260 A CN102701260 A CN 102701260A
- Authority
- CN
- China
- Prior art keywords
- trichloride
- rare earth
- chloride
- chloride solution
- roasting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention belongs to the field of rare earth metallurgy and particularly relates to a spray pyrolysis method for an aid-containing rare earth chloride solution. According to the technical scheme, the method comprises the following steps of: raising the temperature of a roasting furnace to 700 to 1,500 DEG C, mixing a trivalent rare earth chloride solution of which the concentration is 10 to 300g/L and an aid, mixing a mixture and air at the flow speed of 5 to 8,000 liters/hour, spraying into the roasting furnace, and roasting for 1 to 40 minutes to obtain a product, and naturally cooling the product to obtain the powder, wherein the trivalent rare earth hydroxide is 90 to 99 percent based on the weight of the powder. In the process, ammonia water or alkali such as NaOH is not used for precipitating, the pollution of NH<4+>, Na<+> and other ions in the conventional process to water is avoided, the pollution to environment is greatly reduced, and the obtained rare earth oxide product is high in yield and purity.
Description
Technical field
The invention belongs to the rare earth metallurgy field, be specifically related to a kind of method that contains auxiliary agent rare-earth chloride solution spray pyrolysis.
Background technology
Along with science and technology development, obtained application more and more widely as the rare-earth hydroxide of one of base mateiral of novel materials such as preparation nanometer, catalysis, optics.Rare-earth hydroxide is modal intermediates in the Rare Earth Production, can be further used for producing rare earth oxide or as additive of functional materials etc.
It is that ammoniacal liquor or alkali metal hydroxide are added in the solution of rare earth salts that the most frequently used method for preparing rare-earth hydroxide is gone up in industry at present; Obtain the rare-earth hydroxide deposition; The oxyhydroxide that goes out from solution precipitation is adsorbed with water, in drying process, removes with the temperature rising.In 52 pages of " rare earths " that metallurgical industry press publishes rare earth chloride is disclosed and alkali reaction can generate rare-earth hydroxide; 55 pages disclose rare earth oxide and can generate oxyhydroxide with water vapour reacting by heating (being hydrothermal method), in addition in 7 pages of Chemical Industry Press's " rare earth metallurgy " of publishing explanation in the employing hydrothermal method at 193 ~ 420 ℃ and 1.2 * 10
6~ 7 * 10
7Under the Pa condition, in the sodium hydroxide solution of high density, add the rare-earth hydroxide that the rare earth oxide long time treatment can obtain hexagonal.
But in the aforesaid method, be that ammoniacal liquor or alkali precipitation method all can be brought NH
4 +Or Na
+Plasma polluted water problem of resource; And employing rare earth oxide hydrothermal method; Then must at first rare-earth chloride solution be adopted methods such as oxalic acid or carbonic acid hydrogen-oxygen ammonium deposition to be prepared into rare earth oxide, then further with water prepared in reaction rare-earth hydroxide, this must increase raw material consumption.
China utility model patent CN201530727U discloses the device that a kind of pyrolysis solution of cerium chloride by oxidation directly generates ceria oxide powder; Use this device in the time of 200 ℃ to 850 ℃, to generate cerium oxide solid and hydrogen chloride gas; But this patent has only related to maturing temperature; Therefore disclosed equipment of this patent and roasting condition for requiring the cerium oxide transformation efficiency greater than for 95% process method, are very inadequate; The Chinese patent of application number 201010534886.X discloses a kind of preparation method of cerium oxide powder; Provide the solution of cerium chloride by oxidation pyrolysis to prepare the conditions such as strength of solution, maturing temperature and airshed of cerium oxide; And obtained purity greater than 99% cerium oxide powder product; But this patent is little for large-scale production process directive significance only for the small-scale test scale that built in the carrier gas flow velocity is 2 liters/hour; The Chinese patent of application number 201210081225.5 discloses the method that a kind of pyrolytic decomposition prepares the trivalent rare earth oxide compound; Utilize conditions such as temperature in the specification sheets, flow rate of carrier gas, roasting time can obtain the rare earth oxide product; But this patent and above-mentioned two patents are purpose with the preparation rare earth oxide all, all can't obtain can be directly as the rare-earth hydroxide of commercially available prod.
Summary of the invention
To the problem that above-mentioned prior art exists, the present invention provides a kind of method that contains auxiliary agent rare-earth chloride solution spray pyrolysis, can realize that the trivalent rare earth chloride soln directly decomposes the acquisition hydroxide powder, has avoided consumption of raw materials of alkali precipitation process and Na
+, NH
4 +Deng the pollution of alkaline kation to water.
The technical scheme of realization the object of the invention is carried out according to following steps:
With roasting furnace temperature elevation to 700-1500 ℃; With concentration is that the trivalent rare earth chloride soln of 10 ~ 300g/L mixes with auxiliary agent; Be that 5 ~ 8000 liters/hour carrier gas mixes with flow velocity then, spray in the stoving oven roasting 1 ~ 40 minute with Sprayable; The product that obtains obtains the powder of trivalent rare earth oxyhydroxide content 90 wt% ~ 99wt% through naturally cooling.
Described auxiliary agent is that mass concentration is that 20% ~ 30% ydrogen peroxide 50 or mass concentration are 1% ozone solution, and wherein the volume ratio of trivalent rare earth chloride soln and ydrogen peroxide 50 or ozone solution is (1 ~ 25): 10.
Described trivalent rare earth muriate is: Lanthanum trichloride, praseodymium chloride, Neodymium trichloride, samarium trichloride, Europium trichloride, Gadolinium trichloride, Dysprosium trichloride, terbium chloride, Holmium trichloride, Erbium trichloride, thulium chloride, lutecium chloride or Yttrium trichloride.
Described carrier gas is pressurized air or oxygen.
The transformation efficiency that trivalent rare earth chloride soln of the present invention is converted into oxyhydroxide can reach 90 wt% ~ 99wt%, trivalent rare earth oxyhydroxide content 90 wt% ~ 99wt% in the powdered product of acquisition.
The principal reaction that technical scheme of the present invention relates to has:
2RECl
3+6H
2O
2?=2La(OH)
3+6HCl+3O
2↑；
RECl
3+3H
2O+2O
3?=La(OH)
3+3HCl+3O
2↑；
Wherein RE is lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, terbium, holmium, erbium, thulium, lutetium or yttrium.
Compared with prior art, characteristics of the present invention and beneficial effect thereof are:
Because it is raw material that the present invention adopts the trivalent rare earth chloride soln; And ydrogen peroxide 50 or ozone solution that the oxidation reaction product cleanliness without any pollution adopt to take place are as auxiliary agent; Form spraying jointly with carrier gas and carry out roasting; Obtain rare-earth hydroxide, so do not adopt alkali such as ammoniacal liquor or NaOH to precipitate in the production process, do not produce NH in the traditional technology
4 +, Na
+Plasma is to the pollution of water; Greatly reduce pollution to environment; And gained rare earth oxide product yield is high; Purity is high, and the said method of this patent is not only applicable to the pyrolysis of rare-earth chloride solution simultaneously, is equally applicable to liquor alumini chloridi, nickel chloride solution, cobalt chloride solution and ferric chloride Solution(38.
Description of drawings
Fig. 1 is the XRD figure spectrum of the lanthanum hydroxide of the embodiment of the invention 1 preparation;
Fig. 2 is the XRD figure spectrum of the Neodymium trihydroxide of the embodiment of the invention 3 preparations;
Fig. 3 is the XRD figure spectrum of the europium hydroxide of the embodiment of the invention 4 preparations;
Fig. 4 is the XRD figure spectrum of the Yttrium trihydroxide of the embodiment of the invention 6 preparations;
Fig. 5 is the XRD figure spectrum of the erbium hydroxide of the embodiment of the invention 10 preparations.
Embodiment
Used chemical reagent is the AR that market is bought among the present invention;
Calculate behind the content employing U.S. Analyst700 of the PE company type atomic test products middle-weight rare earths element of the rare-earth hydroxide that the embodiment of the invention prepares and the content of chlorine and obtain;
XRD figure is obtained by Japan (Rigaku) D/MAX of science-3B type X-ray diffractometer test.
Below in conjunction with embodiment the present invention is done further explain.
Embodiment 1
At first with roasting furnace temperature elevation to 1500 ℃; Being that lanthanum chloride solution 500ml and the mass concentration of 180g/L is 30% ydrogen peroxide 50 1:10 mixing by volume with concentration then, is that 8000 liters/hour carrier of compressed air is mixed with flow velocity, sprays in the stoving oven; Roasting 1 minute; The product that obtains obtains the powder of lanthanum hydroxide content 90wt% through naturally cooling, and its XRD figure spectrum is as shown in Figure 1.
Embodiment 2
At first with roasting furnace temperature elevation to 1300 ℃; Be that praseodymium chloride solution 400ml and the mass concentration of 180g/L is 20% ydrogen peroxide 50 5:10 mixing by volume with concentration then; With flow velocity is that 5 liters/hour oxygen carrier mixes, and sprays in the stoving oven roasting 20 minutes with Sprayable; The product that obtains obtains the powder of Trihydroxypraseodymium content 99wt% through naturally cooling.
Embodiment 3
At first with roasting furnace temperature elevation to 700 ℃; Being that neodymium chloride solution 100ml and the mass concentration of 200g/L is 25% ydrogen peroxide 50 25:10 mixing by volume with concentration then, is that 1000 liters/hour carrier of compressed air is mixed with flow velocity, sprays in the stoving oven with Sprayable; Roasting 15 minutes; The product that obtains obtains the powder of Neodymium trihydroxide content 97wt% through naturally cooling, and its XRD figure spectrum is as shown in Figure 2.
Embodiment 4
At first with roasting furnace temperature elevation to 1000 ℃; Be that Europium trichloride solution 200ml and the mass concentration of 300g/L is 1% ozone solution 15:10 mixing by volume with concentration then, mix, spray in the stoving oven with Sprayable with the carrier of compressed air of 4000 liters/hour of flow velocitys; Roasting 10 minutes; The product that obtains obtains the powder of europium hydroxide content 98wt% through naturally cooling, and its XRD figure spectrum is as shown in Figure 3.
Embodiment 5
At first with roasting furnace temperature elevation to 900 ℃; Be that Dysprosium trichloride solution 300ml and the mass concentration of 30g/L is 1% ozone solution 1:10 mixing by volume with concentration then; Mix with the carrier of compressed air of 6000 liters/hour of flow velocitys, spray in the stoving oven, roasting 20 minutes with Sprayable; The product that obtains obtains the powder of Dysprosium trihydroxide content 99wt% through naturally cooling.
Embodiment 6
At first with roasting furnace temperature elevation to 1200 ℃; Be that yttrium chloride solution 400ml and the mass concentration of 200g/L is 30% ydrogen peroxide 50 1:1 mixing by volume with concentration then, mix, spray in the stoving oven with Sprayable with the oxygen carrier of 3000 liters/hour of flow velocitys; Roasting 40 minutes; The product that obtains obtains the powder of Yttrium trihydroxide content 92wt% through naturally cooling, and its XRD figure spectrum is as shown in Figure 4.
Embodiment 7
At first with roasting furnace temperature elevation to 1200 ℃; Be that Gadolinium trichloride solution 400ml and the mass concentration of 200g/L is 30% ydrogen peroxide 50 1:1 mixing by volume with concentration then; Mix with the oxygen carrier of 1500 liters/hour of flow velocitys, spray in the stoving oven, roasting 40 minutes with Sprayable; The product that obtains obtains the powder of Gadolinium trihydroxide content 98wt% through naturally cooling.
Embodiment 8
At first with roasting furnace temperature elevation to 1200 ℃; Be that terbium chloride solution 400ml and the mass concentration of 200g/L is 20% ydrogen peroxide 50 1:1 mixing by volume with concentration then; Mix with the oxygen carrier of 800 liters/hour of flow velocitys, spray in the stoving oven, roasting 40 minutes with Sprayable; The product that obtains obtains the powder of terbium hydroxide content 97wt% through naturally cooling.
Embodiment 9
At first with roasting furnace temperature elevation to 1200 ℃; Be that Holmium trichloride solution 400ml and the mass concentration of 300g/L is 30% ydrogen peroxide 50 1:1 mixing by volume with concentration then; Mix with the oxygen carrier of 500 liters/hour of flow velocitys, spray in the stoving oven, roasting 40 minutes with Sprayable; The product that obtains obtains the powder of holmium hydroxide content 99wt% through naturally cooling.
Embodiment 10
At first with roasting furnace temperature elevation to 1200 ℃; Be that Erbium trichloride solution 400ml and the mass concentration of 200g/L is 30% ydrogen peroxide 50 1:1 mixing by volume with concentration then, mix, spray in the stoving oven with the oxygen carrier of 200 liters/hour of flow velocitys; Roasting 40 minutes; The product that obtains obtains the powder of erbium hydroxide content 94wt% through naturally cooling, and its XRD figure spectrum is as shown in Figure 5.
Embodiment 11
At first with roasting furnace temperature elevation to 1200 ℃; Be that thulium chloride solution 400ml and the mass concentration of 100g/L is 30% ydrogen peroxide 50 1:1 mixing by volume with concentration then; Mix with the oxygen carrier of 100 liters/hour of flow velocitys, spray in the stoving oven, roasting 40 minutes with Sprayable; The product that obtains obtains the powder of thulium hydroxide content 96wt% through naturally cooling.
Embodiment 12
At first with roasting furnace temperature elevation to 1500 ℃; Be that lutecium chloride solution 400ml and the mass concentration of 50g/L is 30% ydrogen peroxide 50 1:1 mixing by volume with concentration then; Mix with the oxygen carrier of 80 liters/hour of flow velocitys, spray in the stoving oven, roasting 1 minute with Sprayable; The product that obtains obtains the powder of hydroxide lutetium content 99wt% through naturally cooling.
Embodiment 13
At first with roasting furnace temperature elevation to 900 ℃; With concentration is that samarium trichloride solution 300ml and the mass concentration of 10g/L is 1% ozone solution 1:2 mixing by volume; So mix, spray in the stoving oven roasting 5 minutes with Sprayable with the carrier of compressed air of 20 liters/hour of flow velocitys; The product that obtains obtains the powder of Dysprosium trihydroxide content 99wt% through naturally cooling.
Claims (3)
1. method that contains auxiliary agent rare-earth chloride solution spray pyrolysis is characterized in that carrying out according to following steps:
With roasting furnace temperature elevation to 700-1500 ℃; The trivalent rare earth chloride soln and the auxiliary agent that with concentration are 10 ~ 300g/L are according to volume ratio (1 ~ 25): 10 mix; Be that 5 ~ 8000 liters/hour carrier gas mixes with flow velocity then, spray in the stoving oven roasting 1 ~ 40 minute with Sprayable; The product that obtains obtains the powder of trivalent rare earth oxyhydroxide content 90 wt% ~ 99wt% through naturally cooling; Described auxiliary agent is that mass concentration is that 20% ~ 30% ydrogen peroxide 50 or mass concentration are 1% ozone solution.
2. a kind of method that contains auxiliary agent rare-earth chloride solution spray pyrolysis according to claim 1 is characterized in that described trivalent rare earth muriate is: Lanthanum trichloride, praseodymium chloride, Neodymium trichloride, samarium trichloride, Europium trichloride, Gadolinium trichloride, Dysprosium trichloride, terbium chloride, Holmium trichloride, Erbium trichloride, thulium chloride, lutecium chloride or Yttrium trichloride.
3. a kind of method that contains auxiliary agent rare-earth chloride solution spray pyrolysis according to claim 1 is characterized in that described carrier gas is pressurized air or oxygen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210190297.3A CN102701260B (en) | 2012-06-11 | 2012-06-11 | Spray pyrolysis method for aid-containing rare earth chloride solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210190297.3A CN102701260B (en) | 2012-06-11 | 2012-06-11 | Spray pyrolysis method for aid-containing rare earth chloride solution |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102701260A true CN102701260A (en) | 2012-10-03 |
| CN102701260B CN102701260B (en) | 2014-01-08 |
Family
ID=46894400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210190297.3A Active CN102701260B (en) | 2012-06-11 | 2012-06-11 | Spray pyrolysis method for aid-containing rare earth chloride solution |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102701260B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104449401A (en) * | 2014-12-09 | 2015-03-25 | 东北大学 | Method and device for preparing cerium-based rare earth polishing powder by virtue of spray pyrolysis |
| CN104876254A (en) * | 2015-06-09 | 2015-09-02 | 东北大学 | Method for preparing lanthanum aluminate/lanthanum chromate by spraying pyrolysis |
| CN106017093A (en) * | 2016-05-30 | 2016-10-12 | 内蒙古科技大学 | Roasting device used for preparing rare-earth oxides |
| CN106784780A (en) * | 2017-03-03 | 2017-05-31 | 中南大学 | A kind of nickel-based oxide presoma and its preparation method and application |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5030095A (en) * | 1973-07-23 | 1975-03-26 | ||
| CN101970347A (en) * | 2008-02-08 | 2011-02-09 | 尤米科尔公司 | Doped ceria abrasives with controlled morphology and preparation thereof |
| CN101983925A (en) * | 2010-11-08 | 2011-03-09 | 东北大学 | Preparation method of cerium oxide powder |
-
2012
- 2012-06-11 CN CN201210190297.3A patent/CN102701260B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5030095A (en) * | 1973-07-23 | 1975-03-26 | ||
| CN101970347A (en) * | 2008-02-08 | 2011-02-09 | 尤米科尔公司 | Doped ceria abrasives with controlled morphology and preparation thereof |
| CN101983925A (en) * | 2010-11-08 | 2011-03-09 | 东北大学 | Preparation method of cerium oxide powder |
Non-Patent Citations (3)
| Title |
|---|
| 《高等学校化学学报》 19980430 赵新宇等 喷雾热解制备稀土超细粉末（Ⅰ）--氧化钇粒子形态与形成机理 507-510 1-3 第19卷, 第4期 * |
| YUN CHAN KANG ET AL.: "Preparation of Y2O3 :Eu Phosphor Particles of Filled Morphology at High Precursor Concentrations by Spray Pyrolysis", 《ADV. MATER.》, vol. 12, no. 6, 31 March 2000 (2000-03-31), pages 451 - 453, XP000923879, DOI: doi:10.1002/(SICI)1521-4095(200003)12:6<451::AID-ADMA451>3.3.CO;2-J * |
| 赵新宇等: "喷雾热解制备稀土超细粉末（Ⅰ）——氧化钇粒子形态与形成机理", 《高等学校化学学报》, vol. 19, no. 4, 30 April 1998 (1998-04-30), pages 507 - 510 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104449401A (en) * | 2014-12-09 | 2015-03-25 | 东北大学 | Method and device for preparing cerium-based rare earth polishing powder by virtue of spray pyrolysis |
| CN104449401B (en) * | 2014-12-09 | 2016-07-27 | 东北大学 | A kind of spray-wall interaction prepares method and the device of cerium-based rare earth polishing powder |
| CN104876254A (en) * | 2015-06-09 | 2015-09-02 | 东北大学 | Method for preparing lanthanum aluminate/lanthanum chromate by spraying pyrolysis |
| CN104876254B (en) * | 2015-06-09 | 2016-09-28 | 东北大学 | A kind of spray pyrolysis prepares the method for lanthanum aluminate/Lanthanum Chromite |
| CN106017093A (en) * | 2016-05-30 | 2016-10-12 | 内蒙古科技大学 | Roasting device used for preparing rare-earth oxides |
| CN106017093B (en) * | 2016-05-30 | 2018-02-27 | 内蒙古科技大学 | For preparing the calciner of rare earth oxide |
| CN106784780A (en) * | 2017-03-03 | 2017-05-31 | 中南大学 | A kind of nickel-based oxide presoma and its preparation method and application |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102701260B (en) | 2014-01-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102616826B (en) | Pyrolysis method for preparing trivalent rare earth oxide | |
| CN103539210A (en) | Preparation method of cobalt molybdate microcrystals | |
| CN102701260B (en) | Spray pyrolysis method for aid-containing rare earth chloride solution | |
| CN102531056A (en) | Method for cleaner production of sodium vanadate and sodium chromate by pressure leaching of vanadium slag | |
| CN103071807A (en) | Preparation method of ultra-fine spherical cobalt powder | |
| CN104538629A (en) | Method for preparing spherical nano iron phosphate | |
| CN103318939A (en) | Method for preparing solid spherical rare earth oxide in one-step spraying thermal decomposition mode | |
| CN102212700A (en) | Production method of high-purity anhydrous zinc chloride | |
| CN102146513A (en) | Method for extracting vanadium from vanadium-containing ore by oxidation acid-leaching wet method | |
| CN103073039A (en) | Method for preparing superfine carbonate powder material | |
| CN101983925B (en) | Preparation method of cerium oxide powder | |
| CN108751260A (en) | A kind of preparation method of perovskite type rare earth complex oxide | |
| CN112246244B (en) | Preparation method and application of copper-copper oxide-copper cobaltate catalyst with adjustable oxygen vacancy content | |
| CN101439882B (en) | Method for synthesizing mesoporous ammonium nickel molybdate by using urea as precipitating agent | |
| CN101863662A (en) | Method for preparing nano boron powder | |
| CN102126736A (en) | Method for preparing nano-calcium carbonate powder by using soluble carbonate | |
| Li et al. | A novel hydrolysis method to synthesize chromium hydroxide nanoparticles and its catalytic effect in the thermal decomposition of ammonium perchlorate | |
| CN101195495A (en) | Process for producing high purity nano-lithium fluoride | |
| CN103318976B (en) | A kind of technique being prepared tricobalt tetroxide by cobalt-carrying solution | |
| CN110331297B (en) | Method for preparing vanadium pentoxide from vanadium slag in short process | |
| CN103303961B (en) | Preparation method of spherical electroplating-level copper oxide powder | |
| CN102849692A (en) | Preparation method of high oriented tungsten biselenide nanowire | |
| CN103449482B (en) | A kind of method utilizing serpentine to prepare magnesium oxide, nickel, cobalt and white carbon black | |
| WO2017041738A1 (en) | Recycling process of wastewater containing ammonium ion and preparation method of metal oxide | |
| CN103449511A (en) | Strontium titanate submicron crystal and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20230817 Address after: Room 1803, Building B, Dongding International, No. 600 Mohe Road, Baoshan District, Shanghai, 2019 Patentee after: SHANGHAI BAOJIN METALLURGICAL TECHNOLOGY Co.,Ltd. Address before: 110819 No. 3 lane, Heping Road, Heping District, Shenyang, Liaoning 11 Patentee before: Northeastern University |
|
| TR01 | Transfer of patent right |