TW200827305A - The recycling method of silicon sludge after slicing - Google Patents
The recycling method of silicon sludge after slicing Download PDFInfo
- Publication number
- TW200827305A TW200827305A TW95150091A TW95150091A TW200827305A TW 200827305 A TW200827305 A TW 200827305A TW 95150091 A TW95150091 A TW 95150091A TW 95150091 A TW95150091 A TW 95150091A TW 200827305 A TW200827305 A TW 200827305A
- Authority
- TW
- Taiwan
- Prior art keywords
- mud
- recovering
- silicon
- cleaning
- remove
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 35
- 239000010802 sludge Substances 0.000 title claims abstract description 10
- 238000004064 recycling Methods 0.000 title abstract description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title abstract 11
- 229910052710 silicon Inorganic materials 0.000 title abstract 11
- 239000010703 silicon Substances 0.000 title abstract 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 19
- 229910001868 water Inorganic materials 0.000 claims abstract description 15
- 239000012535 impurity Substances 0.000 claims abstract description 8
- 238000005119 centrifugation Methods 0.000 claims description 28
- 238000000926 separation method Methods 0.000 claims description 25
- 238000005520 cutting process Methods 0.000 claims description 22
- 238000011084 recovery Methods 0.000 claims description 19
- 239000004575 stone Substances 0.000 claims description 19
- 229910052799 carbon Inorganic materials 0.000 claims description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 15
- 238000004140 cleaning Methods 0.000 claims description 15
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 14
- 239000007788 liquid Substances 0.000 claims description 13
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 8
- 239000008396 flotation agent Substances 0.000 claims description 8
- 229960002050 hydrofluoric acid Drugs 0.000 claims description 8
- 238000005554 pickling Methods 0.000 claims description 8
- 239000012459 cleaning agent Substances 0.000 claims description 7
- 230000005484 gravity Effects 0.000 claims description 7
- 238000005406 washing Methods 0.000 claims description 7
- 239000002253 acid Substances 0.000 claims description 6
- NFFIWVVINABMKP-UHFFFAOYSA-N methylidynetantalum Chemical compound [Ta]#C NFFIWVVINABMKP-UHFFFAOYSA-N 0.000 claims description 5
- 229910003468 tantalcarbide Inorganic materials 0.000 claims description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 4
- 150000001450 anions Chemical class 0.000 claims description 4
- 229910000420 cerium oxide Inorganic materials 0.000 claims description 4
- 230000008859 change Effects 0.000 claims description 4
- 239000008367 deionised water Substances 0.000 claims description 4
- 229910021641 deionized water Inorganic materials 0.000 claims description 4
- 238000004090 dissolution Methods 0.000 claims description 4
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid group Chemical group S(O)(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 4
- 229910052797 bismuth Inorganic materials 0.000 claims description 3
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 3
- 150000001768 cations Chemical class 0.000 claims description 3
- 239000004576 sand Substances 0.000 claims description 3
- RVHSTXJKKZWWDQ-UHFFFAOYSA-N 1,1,1,2-tetrabromoethane Chemical compound BrCC(Br)(Br)Br RVHSTXJKKZWWDQ-UHFFFAOYSA-N 0.000 claims description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 2
- 238000004220 aggregation Methods 0.000 claims description 2
- 230000002776 aggregation Effects 0.000 claims description 2
- 239000002002 slurry Substances 0.000 claims description 2
- 238000001291 vacuum drying Methods 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims 3
- 241001674044 Blattodea Species 0.000 claims 2
- 206010020850 Hyperthyroidism Diseases 0.000 claims 1
- 238000009825 accumulation Methods 0.000 claims 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims 1
- 239000010931 gold Substances 0.000 claims 1
- 229910052737 gold Inorganic materials 0.000 claims 1
- 229910052739 hydrogen Inorganic materials 0.000 claims 1
- 239000001257 hydrogen Substances 0.000 claims 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims 1
- 150000002500 ions Chemical class 0.000 claims 1
- 239000007769 metal material Substances 0.000 claims 1
- 229910017604 nitric acid Inorganic materials 0.000 claims 1
- 239000012085 test solution Substances 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 20
- 239000013078 crystal Substances 0.000 abstract description 13
- 239000000463 material Substances 0.000 abstract description 8
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 abstract description 6
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 abstract 2
- 229910010271 silicon carbide Inorganic materials 0.000 abstract 2
- 239000000314 lubricant Substances 0.000 abstract 1
- 230000003340 mental effect Effects 0.000 abstract 1
- 235000012431 wafers Nutrition 0.000 abstract 1
- 239000007787 solid Substances 0.000 description 21
- 230000000694 effects Effects 0.000 description 16
- 229910052751 metal Inorganic materials 0.000 description 16
- 239000002184 metal Substances 0.000 description 15
- 239000000843 powder Substances 0.000 description 10
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 8
- 238000002474 experimental method Methods 0.000 description 7
- 238000000227 grinding Methods 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- 238000003763 carbonization Methods 0.000 description 5
- UNASZPQZIFZUSI-UHFFFAOYSA-N methylidyneniobium Chemical compound [Nb]#C UNASZPQZIFZUSI-UHFFFAOYSA-N 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 229910052712 strontium Inorganic materials 0.000 description 5
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 5
- 239000010432 diamond Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 4
- 229910052715 tantalum Inorganic materials 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- WXANAQMHYPHTGY-UHFFFAOYSA-N cerium;ethyne Chemical compound [Ce].[C-]#[C] WXANAQMHYPHTGY-UHFFFAOYSA-N 0.000 description 3
- 239000000356 contaminant Substances 0.000 description 3
- 239000003344 environmental pollutant Substances 0.000 description 3
- 239000008187 granular material Substances 0.000 description 3
- 150000002576 ketones Chemical class 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 239000010687 lubricating oil Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 231100000719 pollutant Toxicity 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- DIKBFYAXUHHXCS-UHFFFAOYSA-N bromoform Chemical compound BrC(Br)Br DIKBFYAXUHHXCS-UHFFFAOYSA-N 0.000 description 2
- 239000000701 coagulant Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 238000004945 emulsification Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 229910052707 ruthenium Inorganic materials 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 101100422889 Arabidopsis thaliana SWI3A gene Proteins 0.000 description 1
- 229910001369 Brass Inorganic materials 0.000 description 1
- 229910052684 Cerium Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- ZMIGMASIKSOYAM-UHFFFAOYSA-N cerium Chemical compound [Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce] ZMIGMASIKSOYAM-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 235000003642 hunger Nutrition 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 210000004185 liver Anatomy 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 238000010025 steaming Methods 0.000 description 1
- FZUJWWOKDIGOKH-UHFFFAOYSA-N sulfuric acid hydrochloride Chemical compound Cl.OS(O)(=O)=O FZUJWWOKDIGOKH-UHFFFAOYSA-N 0.000 description 1
- 229910021654 trace metal Inorganic materials 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 239000000052 vinegar Substances 0.000 description 1
- 235000021419 vinegar Nutrition 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/037—Purification
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/30—Wastewater or sewage treatment systems using renewable energies
- Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Silicon Compounds (AREA)
- Separation Of Solids By Using Liquids Or Pneumatic Power (AREA)
- Manufacture And Refinement Of Metals (AREA)
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW95150091A TW200827305A (en) | 2006-12-29 | 2006-12-29 | The recycling method of silicon sludge after slicing |
| US12/004,485 US8034313B2 (en) | 2006-12-29 | 2007-12-21 | Recovery method of silicon slurry |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW95150091A TW200827305A (en) | 2006-12-29 | 2006-12-29 | The recycling method of silicon sludge after slicing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| TW200827305A true TW200827305A (en) | 2008-07-01 |
| TWI337983B TWI337983B (enExample) | 2011-03-01 |
Family
ID=42631133
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| TW95150091A TW200827305A (en) | 2006-12-29 | 2006-12-29 | The recycling method of silicon sludge after slicing |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US8034313B2 (enExample) |
| TW (1) | TW200827305A (enExample) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI417938B (zh) * | 2008-09-19 | 2013-12-01 | Wei Ming Chang | 一種處理矽晶板切割廢棄物的製程及裝置 |
| TWI712559B (zh) * | 2019-01-25 | 2020-12-11 | 國立臺北科技大學 | 碳化矽與矽的分離方法（一） |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2303776B1 (en) * | 2008-07-09 | 2014-04-16 | Garbo S.r.l. | Method for purification and compaction of feedstock for photovoltaic applications |
| TWI392647B (zh) * | 2009-05-11 | 2013-04-11 | 國立台灣大學 | 以粒子相轉移法回收切割矽泥中的矽與碳化矽粉 |
| TW201144222A (en) * | 2010-06-04 | 2011-12-16 | Hong Jing Environment Company | A method for the silicon recycling |
| US8734751B2 (en) * | 2011-06-12 | 2014-05-27 | Taiwan Water Recycle Technology Co., Ltd. | Method and apparatus for recycling and treating wastes of silicon wafer cutting and polishing processes |
| CN102350411A (zh) * | 2011-09-08 | 2012-02-15 | 中国石油天然气集团公司 | 聚对苯二甲酸1,3-丙二醇酯的连续切粒结晶干燥装置 |
| DE102011115081B4 (de) | 2011-09-19 | 2017-08-31 | Baufeld-Mineralölraffinerie GmbH | Verfahren zur Gewinnung von Solarsilizium aus Sägeabfällen |
| CN102642835A (zh) * | 2012-04-19 | 2012-08-22 | 镇江环太硅科技有限公司 | 从金刚线切割晶硅产生的废料中回收硅料的方法 |
| CN102642837B (zh) * | 2012-04-27 | 2013-07-24 | 河南新大新材料股份有限公司 | 从金刚石线锯切割硅片废料浆中回收多晶硅的方法 |
| TWI481569B (zh) * | 2012-08-16 | 2015-04-21 | The Total Resource Processing Technology of Waste Cutting Oil | |
| CN105084367B (zh) * | 2015-08-18 | 2017-03-08 | 北京科技大学 | 电位分散‑微波酸洗法去除多晶硅线切割废料杂质的方法 |
| EP3584355A1 (en) * | 2018-06-18 | 2019-12-25 | Total SA | Method for recycling sub-micron si-particles from a si wafer production process and silicon wafer production facility |
| CN109103073A (zh) * | 2018-08-29 | 2018-12-28 | 汉能新材料科技有限公司 | 一种废弃晶片的再利用方法及制备得到的晶片 |
| CN113582184B (zh) * | 2021-08-06 | 2023-09-19 | 河南盛达光伏科技有限公司 | 一种碎硅料杂质的提纯方法 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6780665B2 (en) * | 2001-08-28 | 2004-08-24 | Romain Louis Billiet | Photovoltaic cells from silicon kerf |
-
2006
- 2006-12-29 TW TW95150091A patent/TW200827305A/zh unknown
-
2007
- 2007-12-21 US US12/004,485 patent/US8034313B2/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI417938B (zh) * | 2008-09-19 | 2013-12-01 | Wei Ming Chang | 一種處理矽晶板切割廢棄物的製程及裝置 |
| TWI712559B (zh) * | 2019-01-25 | 2020-12-11 | 國立臺北科技大學 | 碳化矽與矽的分離方法（一） |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI337983B (enExample) | 2011-03-01 |
| US8034313B2 (en) | 2011-10-11 |
| US20100215561A1 (en) | 2010-08-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TW200827305A (en) | The recycling method of silicon sludge after slicing | |
| JP5114436B2 (ja) | 金属含有物除去方法およびシリコン精製方法 | |
| TWI392647B (zh) | 以粒子相轉移法回收切割矽泥中的矽與碳化矽粉 | |
| JP2001278612A (ja) | シリコンの回収方法 | |
| TW200844050A (en) | Silicon reclamation apparatus and method of reclaiming silicon | |
| JP2008290897A (ja) | シリコン回収方法及びシリコン回収装置 | |
| TW201008873A (en) | Method for purification and compaction of feedstock for photovoltaic applications | |
| TW200840802A (en) | Method for recycling silicon slurry | |
| CN112919477A (zh) | 半导体废硅泥的二氧化硅再生方法 | |
| JP2010070425A (ja) | シリコンの再生方法 | |
| CN111777070A (zh) | 一种金刚石线硅片切割废料高值化再生利用的方法 | |
| CN1849264A (zh) | 铈盐、其制造方法、氧化铈以及铈系研磨剂 | |
| TW200841991A (en) | Process and apparatus for treating exhausted abrasive slurries from the lapping process for the recovery of their reusable abrasive component | |
| TW200946452A (en) | Silicon regenerating method | |
| TW201144222A (en) | A method for the silicon recycling | |
| JP5001589B2 (ja) | 廃スラッジからのシリコンの製造方法 | |
| JP5286095B2 (ja) | シリコンスラッジ回収方法およびシリコン加工装置 | |
| CN102530948B (zh) | 一种从硅片切割锯屑中回收硅的方法 | |
| JP2009084069A (ja) | シリコン再生装置、シリコン再生方法 | |
| CN107986284A (zh) | 一种从蓝宝石研磨废料中回收利用碳化硼的方法 | |
| CN102659113B (zh) | 微孔膜过滤法回收单晶和多晶硅线切割废料中硅粉的方法 | |
| TW200804181A (en) | Method of recovering silicon-containing material | |
| CN102179528A (zh) | 沉淀透气还原纳米银粉的制备方法 | |
| TWI481569B (zh) | The Total Resource Processing Technology of Waste Cutting Oil | |
| KR100586642B1 (ko) | Ｗｉｒｅ Ｓａｗ 슬러리로부터 실리콘 카바이드의 선택적 회수방법 |