Studies on the reactivity of thiophosphate/thiophosphinate and ethyl xanthate with precious metals

Simple item page
dc.contributor.authorKim, DongSuen
dc.contributor.committeechairYoon, Roe-Hoanen
dc.contributor.committeememberAdel, Gregory T.en
dc.contributor.committeememberRichardson, P. E.en
dc.contributor.committeememberLuttrell, Gerald H.en
dc.contributor.committeememberNagaraj, D. R.en
dc.contributor.committeememberReifsnider, Kenneth L.en
dc.contributor.departmentMaterials Engineering Scienceen
dc.date.accessioned2014-03-14T21:21:56Zen
dc.date.adate2005-10-21en
dc.date.available2014-03-14T21:21:56Zen
dc.date.issued1992-12-05en
dc.date.rdate2005-10-21en
dc.date.sdate2005-10-21en
dc.description.abstractAdsorption mechanisms of modified thiol collectors on gold, silver, and gold-silver alloys have been studied and compared with those of ethyl xanthate (EX). The modified thiol collectors include dicresyl monothiophosphate (DCMTP), dialkyl dithiophosphinate (DTPI) and monothiophosphinate (MTPI). In general, the adsorption mechanisms on silver and gold-silver alloys can be explained by the EC-mechanism involving an electron transfer step and a chemical reaction step. Thus, the adsorption should be controlled by the Eh of the electrochemical oxidation of the electrode involved and the pK of the metal collector complex. According to this mechanism, DCMTP should adsorb on silver and gold-silver alloys at a lower potential than DTPI and MTPI since the pK of silver-DCMTP complex is larger than those of silver-DTPI and silver-MTPI. This has been verified to be the case by voltammetry, FTIR and contact angle studies. Likewise, EX adsorbs on silver at a lower potential than the modified thiol collectors because the pK of silver-EX is larger than those of the silver-modified thiol collectors. Both EX and the modified thiol collectors adsorb on silver at lower potentials than on the gold-silver alloys, which can be attributed to the lower activity of silver on the alloy surface. For the same reason, the potential for the onset of collector adsorption on alloys decreases with increasing silver content.en
dc.description.degreePh. D.en
dc.format.extentxv, 184 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-10212005-123010en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10212005-123010/en
dc.identifier.urihttp://hdl.handle.net/10919/40071en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V856_1992.K5584.pdfen
dc.relation.isformatofOCLC# 29179348en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V856 1992.K5584en
dc.subject.lcshAdsorptionen
dc.subject.lcshPotassium ethylxanthateen
dc.subject.lcshPrecious metalsen
dc.subject.lcshThiolsen
dc.subject.lcshThiophosphatesen
dc.titleStudies on the reactivity of thiophosphate/thiophosphinate and ethyl xanthate with precious metalsen
dc.typeDissertationen
dc.type.dcmitypeTexten
thesis.degree.disciplineMaterials Engineering Scienceen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
LD5655.V856_1992.K5584.pdf
Size:
4.35 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations