直接电解还原二氧化硅制备高纯硅的研究_英文_

第46卷　增　刊2007年　6月中山大学学报(自然科学版)ACT A S C I E NTI A RUM NAT URAL I U M UN I V ERSI T ATI S S UNY ATSE N I Vol 146　Sup 1Jun 1　2007I nvesti ga ti on of D i rect Electrolyti c Reducti onof Soli d S iO 2to S i with H i gh Pur ityL I U Yi 2ke,MA W en 2hu i,YAN G B in,DA I Yong 2nian(Faculty ofMaterials and metallurgical Engineering ∥Nati onal Engineering Laborat ory of Vacuu m Metallurgy,Kunm ing University of Science and Technol ogy,Kunm ing 650093,China )Abstract :A new way using op tical fiber wastes as ra w material f or the p reparati on of electr olytic reducti on of s olid Si O 2t o Si in molten chl orides was p r oposed t o be a considerable technol ogy t o p repare s olar grade silicon (S OG 2Si ).It has s ome advantages such as l ow cost and energy consu mp ti on,envir on mental p r otecti on,si m p le p r oducti on fl ow and ultra 2high purity p r oduct .The f or med Si was con 2fir med by Ra man s pectr oscopy .Key words :s olar grade silicon;op tical fiber wastes;Si O 2;electr olytic reducti onCLC nu m ber :O613172;TF114 D ocu m en t code :A Arti cle I D :052926579(2007)S120333202W ith the devel opment of P V industry the traditi on 2al supp ly falls short of the de mand .a ne w technol ogy is needed t o p repare S OG 2Si with abundant feedst ock sup 2p ly and l ow cost and energy consu mp ti on .Recently,Yasuda [1-3]f ound electr olytic reducti on of Si O 2t o Si is feasible in molten chl orides such as CaCl 2.H igh purity silicon will be p repared just re mo 2ving oxygen fr om high purity Si O 2by this method .I n this paper,author investigated a ne w way t o recycle sil 2ica op tical fiber wastes f or feedst ock supp ly of s olar grade silicon on the basis of direct electr olytic reducti on of s olid Si O 2t o Si in molten chl orides .A ne w method and p r oducti on fle w sheet of S OG 2Si was p r oposed .And Si had been p repared via direct electr olytic reduc 2ti on of fiber 2op tic r ods used which are made of ultra 2high purity silica glass .1　A new way to prepare S O G 2S iA ne w si m p le p r oducti on fl ow p r oposed by authorscombinati on recycling of wastes with p reparati on of high purity of silicon directly for feedst ock supp ly of S OG 2Si,was show in Fig 11,which suggests that silicon with high purity at l ow cost and energy consump ti on could be realized via re melt method p r ocess .This ne w meth 2od was p r oposed t o be a ne w technol ogy t o p repare S OG 2Si .For this way,there are s ome advantages:(1)The feedst ock supp ly can be easily acquired fr om a large number of op tical fiber wastes which aregenerating every year .A s a new efficient way f or recy 2cling op tical fibers wastes,it can p r otect envir onments and av oid wasting high -purity silica res ource and po 2tential high 2energy.Fig 11　Ne w p r oducti on fl ow(2)The energy consu mp ti on and the cost of the method are l ow .(3)The p reparati on method is si m p le and the p r oduct purity is high .2　Exper i m en t a lOp tic fiber r ods used which are made of ultra 2high purity silica glass was washed in distill water .And u 2sing the m made up of contacting electr ode .A Si O 2con 2tacting electr ode was p repared by equally winding a Mo wire and copper wire as a current lead,about thirty ti m es ar ound a quartz glass r od .The counter electr ode①收稿日期:2007201210基金项目:国家科技支撑计划重点资助项目(2006BAE01B08);国家自然科学基金资助项目(50674050);教育部博士点基金资助项目(20060674004);云南省中青年学术带头人后备人才资助项目(2005PY01-33)作者简介:刘仪柯(1981年生),男,硕士生;通讯联系人:马文会;E 2mail:mwhui@k must 1edu 1cn中山大学学报(自然科学版)第46卷　was a graphite r od .1000g anhydr ous calciu m chl oride (reagent grade )was contained in a sealed stainless steel react or after p retreat m ent .And the te mperature of reacti on is 850℃.Sa mp les were p repared by potenti ostatic electr oly 2sis at 1110V (vs .Ca 2+/Ca )for 1h,and analyzed after washing in distilled water and re moving the Mo wire .Sa mp les were analyzed by Ra man s pectr oscopy (A rgon i on,51415n m ,Renishaw Cor p.)Fig 12　Ra man s pectra of sa mp le after electr olysis at1110V f or 1hour in the molten CaCl 2at 850℃3　Results and d iscussi on sThe Ra man s pectru m of the si m p le are showed inFig 12f or different measure p rints in the sa me sa mp le .Fr om the Ra man s pectru m of sa mp le we can observe apeak bet w een 400and 550c m -1of Ra man shift .Thepeak consisted of t w o peaks,one is ar ound 475c m -1related t o a mor phous Si which has a peak r ound 480c m -1,and the other is related t o crystal silicon whichhas a peak ar ound 520c m -1[5].Si O 2reducti on t o Si had been confir med .4　Conclusi on s(1)A ne w technique t o p reparati on of S OG 2Si was p r oposed,which has s ome advantages such as l ow cost and energy consu mp ti on,p r oduct meeting the re 2quired quality for S OG 2Si and si m p le p r oducti on fl ow sheet .(2)Si has been p repared via direct electr olytic reducti on of fiber 2op tic r ods used which are made of ul 2tra 2high purity silica glass .The for med Si was con 2fir med by Ra man s pectr oscopy .(3)A s a ne w efficient way f or recycling op tical fi 2bers wastes,it can p r otect envir onment and recycle waste high 2purity silica res ource and potential high 2en 2ergy .References:[1]　Y AS UDA K,I RA T,I T O Y .Effect of electr olysispotential on reducti on of s olid silicon di oxide in molten CaCl 2[J ].Journal of Physics and Chem istry of Solids,2005,66:443-447.[2]　NOH I RA T,Y AS UDA K,I T O Y .Pinpa m t and bulkelectr oche m ical reducti on of insulating silicon di oxide t o silicon [J ].Nature Materials,2003,2:397-401.[3]　Y AS UDA K,NOH I RA T,AMEZ AWA K .Mechanis mof direct electr olytic reducti on of s olid Si O 2t o Si in mol 2ten CaCl 2[J ].Journal of the Electr oche m ical Society,2005,152(4):69-74.[4]　MA W H,OG URA M ,K OBY ASH I T .Preparati on ofs olar grade silicom fr om op tical fibarswastes with ther malp las mas [J ].Solar Energy Materids &Solar Cells,2004,81:477-483.[5]　KI M URA Y,K AT ODA T .Effects of strain on crystalli 2zati on of a mor phous silicon characterized by laser Ra man s pectr oscopy [J ].App lied Surface Science,1997,117/118:790-793.直接电解还原二氧化硅制备高纯硅的研究刘仪柯,马文会,杨　斌,戴永年(昆明理工大学材料与冶金工程学院∥真空冶金国家工程实验室,云南昆明650093)摘　要:提出了以废弃石英光纤为原料,利用熔盐直接电解还原Si O 2来制备太阳能级硅的新思路设计,该设计具有低成本低能耗、环保、工艺流程简单以及产品纯度高等优点。