Phosphorus separation from metallurgical-grade silicon by magnesium alloying and acid leaching
Peer reviewed, Journal article
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Date
2020Metadata
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- Institutt for materialteknologi [2503]
- Publikasjoner fra CRIStin - NTNU [37290]
Abstract
n this paper, the separation of phosphorus from metallurgical-grade silicon was investigated based on an Mgalloying and HCl leaching approach. Experimental results show that P concentration was reduced from initial15.1ppmwto0.2ppmwwithalsolargeextentremovalofmetallicimpuritiesbytwotimesMgalloying-leachingpurification.ThemechanismofenhancedPseparationisclarifiedowingtothestrongaffinitybetweenMgandP,whichisvalidatedbySIMSelementalmapping.Atwo-parameteranalyticalmodelwasdevelopedtopredicttheP removal degree based on the variables of alloying metal concentration and interaction coefficient betweenalloyingmetalandP.Themodelisvalidatedwith experimentalresultsandtheinteractioncoefficientflg in “iXwasobtainedas−10.8.ThisapproachcanbeappliedtomodeltheremovalofimpuritywhichfollowsGulliver-Scheil solidification from other binary alloying systems. Furthermore, in order to study the effect of appliedalloying-leaching operation times, a model was proposed which establishes the mathematical relationshipsamongkeyprocessingvariableslikeinitialandtargetPconcentrations,theamountofthealloyingmetal,andtheprocess operation times