熔鹽電解法制備硅粉的基礎研究——體系相結構、表面張力和電導率的研究.pdf

1、河北理工大學碩士學位論文熔鹽電解法制備硅粉的基礎研究——體系相結構、表面張力和電導率的研究姓名：周靜申請學位級別：碩士專業(yè)：有色金屬冶金指導教師：李運剛20070401河北理t大學碩士學位論文AbstractSiliconhashighermeltingpoint，intensity，hardness，wellknownchemicalstabilityandsemiconductorcapabilityTherefore，itsapp

2、licationisextensivewithusingonceBecauseofitshighproductioncosts，inordertodecreasetheproductioncostsofsilicon，therearetheoreticsignificanceandappliedvaluetoempoldernewmethodsofproductionsilicon，atpresentInthepresentwork，t

3、hetechnicsofsiliconpowderpreparationandqualityofsystemarestudiedbyelectrodepositionmethodinNaCl—KClNaF—Si02systemforthefirsttimeThermodynamicscalculationalmethodhasbeenappliedtoinvestigatethesolutionmechanismofSi02inNaCl

4、KClNaFsystemItwasfoundthattherewerenewsubstance1ikeNa2SiF6andNa2Si03，tobemadeonlyAtthesametime，newsubstancewaseasytobeproducedalongwithincreasingNaFXl也slidemethodaswellasfourparallelelectrodemethodhavebeenappliedtoinvest

5、igaterespectivelyslagstructureandhydroniumcomposition，surfacetensionandconductivityInNaClKClNaFSi02systemforthefirsttimeItwasshownthatthemainphasesinmeltsareNa2SiF6、NaCl、KClandNaF111econtentofNa2SiF6relatestoNaCl、KCl、NaF

6、IthasfavourablelinearityrelationbetweensurfacetensionandtemperatureIntherangeof740。Cto900“C，thesurfacetensionofthesystemisreducedwitlItemperatureriseStepbystepsubstitutingKCIforNaFdecreasesthesurfacetensionofthesystemtom

7、inimumwhenratioofXNaOlCKCland抵aFequalstol，thenthesurfacetensionincreasesalongwithKCIriseReplacingNaCIforNaFreducesthesurfacetensionofthesystemtominimumwhenratioof抵acIAKcandj，NaFequalstol，thenthesurfacetensionincreasesalo

8、ngwithNaC!riseAttheratioof抵nCltoXKobeing1，thesurfacetensioninmeltsrisesalongwitllNaFincreasinggraduallyTherelationbetweenconductivityandtemperaturefollowsgenerflmleofconductivityinmoltensaltStagebystagesubstitutingKCIfor

9、NaFdecreasestheconductivityofthesystemtominimumwhenratioofXNaOXKcand抵aFequalstol，thentheconductivityincreasesalongwithKC!riseReplacingNaCIforNaFfallstheconductivityofthesystemtominimumwhenratioofj，NacIXKoand抵aFequalsto1，