Surface enhanced raman scattering spectroelectrochemical studies of mineral processing

• Autorzy: Hope G. A. , Woods R. , Watling K.

Warianty tytułu

PL

Badania spektrochemiczne SERS w przeróbce kopalin

• Języki publikacji: EN

Abstrakty

EN

The application of in situ surface enhanced Raman scattering (SERS) spectroscopy to aspects of mineral processing is discussed. In the study of flotation systems, SERS has been used to characterise the species formed on coinage metal surfaces over a range of controlled potentials for ethyl, i-propyl, i-butyl and i-amyl xanthates, for O-isopropyl-N-ethylthionocarbamate (IPETC), for 2-mercaptobenzothiazole (MBT), and for diisobutyl dithiophosphinate (DIBDTPI). For each collector, adsorption occurs via charge transfer to form a metal-sulfur bond and, in situations in which the reversible potential for the formation of the bulk phase is known, at underpotentials. The dissolution of silver in basic solutions containing cyanide has been shown to be inhibited by MBT and by DIBDTPI as a result of the chemisorption of the collector species. In hydrometallurgy, SERS has been applied to the investigation of gold leaching. Changes in the surface species that occur during gold cyanidisation as the potential is varied have been identified from SERS spectra recorded in real time on voltammograms. In electrometallurgy, SERS investigations of copper electrodeposition from sulfuric acid solutions have shown that a transient surface sulfate species is involved in the plating process.

PL

W pracy przedyskutowano zastosowania spektroskopii rozproszenia ramanowskiego (ze wzmocnieniem sygnału wskutek odbicia promieniowania od powierzchni - SERS) w badaniach związanych z procesami przeróbki minerałów w których widmo wykonywane jest in situ. W układach flotacyjnych zastosowano SERS do charakterystyki pokryć na metalach z grupy miedzi, powstających w wyniku oddziaływania na te metale w warunkach kontrolowanego potencjału roztworów ksantogenianów: etylowego, izopropylowego, izobutylowego i izoamylowego, a także o-izopropylo-Netylotionocarbaminianu, 2-merkaptobenzotiazolu oraz dwuizobutylo dwutiofosfonianu. W przypadku wszystkich kolektorów adsorpcja następuje w wyniku przeniesienia ładunku z wytworzeniem wiązania metal-siarka, a jeśli znany jest odwracalny potencjał tworzenia fazy objętościowej to można stwierdzić, że wiązanie z powierzchnią następuje przy potencjale niższym niż dla reakcji w fazie objętościowej. Zaobserwowano, że roztwarzanie srebra w zasadowych roztworach cyjankowych jest silnie spowalniane w wyniku chemisorbcji 2-merkaptobenzotiazolu i dwuizobutylo dwutiofosfonianu. W zakresie hydrometalurgii zastosowano SERS do badania ługowania złota. Stosując rejestrację widm SERS w trakcie wykonywania woltamperogramów przy zmieniającym się potencjale obserwowano zmiany w składzie warstw powierzchniowych na złocie w wyniku traktowania powierzchni złota cyjankami przy różnych potencjałach. SERS zastosowano również do badania procesów elektrometalurgicznych, stwierdzając że w procesach osadzania miedzi z kwaśnych roztworów siarczanowych bierze udział przejściowy produkt zawierający grupę siarczanową.

Słowa kluczowe

EN

spectroelectrochemistry; Raman spectroscopy; collector adsorption; gold leaching; copper electrodeposition

PL

spektroskopia rozproszenia; badania spektrochemiczne; SERS; przeróbka kopalin

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Physicochemical Problems of Mineral Processing
• Rocznik: 2002
• Tom: Vol. 36
• Strony: 21--38
• Opis fizyczny: Bibliogr. 35 poz., wykr.

Twórcy

autor

Hope G. A.

• School of Science, Griffith University, Nathan, Queensland 4111, Australia

autor

Woods R.

• School of Science, Griffith University, Nathan, Queensland 4111, Australia

autor

Watling K.

• School of Science, Griffith University, Nathan, Queensland 4111, Australia

Bibliografia

• BOTT, R C., BOWMAKER, G.A., DAVIS, C.A., HOPE, G.A. and JONES, B.E. (1998), Crystal structure of [Cu4tu7](SO4)2.H20 and vibrational spectroscopic studies of some copper (i) thiourea complexes, Inorganic Chemistry, Vol. 37, 651-657.
• BROWN G.M. and HOPE, G.A. (1995) In-situ spectroscopic evidence for the adsorption of SO42- ions at a copper electrode in sulfuric acid solution, J. Electroanal. Chem., Vol. 382, 179-182.
• BROWN G.M. and HOPE, G.A. (1996), Confirmation of thiourea/chloride ion co-adsorption at a copper electrode by in situ SERS spectroscopy, J. Electroanal. Chem., 413 (1996) 153-160.
• BROWN, G.M., HOPE, G.A., SCHWEINSBERG D.P. and FREDERICKS, P.M. (1995), SERS study of the interaction of thiourea with a copper electrode in sulphuric acid solution, J. Electroanal. Chem., 380 (1995) 161-166.
• BUCKLEY A.N. and WOODS, R. (1996), Relaxation of the lead-deficient sulfide surface layer on oxidized galena, J. Appl. Electrochem., Vol. 26, 899 - 907.
• BUCKLEY, A.N., HOPE, G.A. and WOODS, R. (2002), Metals from sulfide minerals: the role of adsorption of organic reagents in processing technologies, Solid-Liquid Interfaces Macroscopic Phenomena - Microscopic Understanding (K. Wandelt and S. Thurgate, Eds) Topics in Applied Physics, Vol. 85, Springer; Germany, pp. 59-94.
• BUCKLEY, A.N., PARKS, T.J., VASSALLO, A.M. and WOODS, R. (1997), Verification by surface enhanced Raman spectroscopy of the integrity of xanthate chemisorbed on silver, Int. J. Miner. Process., Vol. 51 303-313.
• FLEISCHMANN, M.; HENDRA, P. J. and McQUILLAN, A. J. (1974), Raman spectra of pyridine adsorbed at a silver electrode., Chem. Phys.Lett. , 26, 163-166.
• FLEISCHMANN, M., SOCKALINGUM, D. and MUSIANI, M.M. (1990), The use of near infrared Fourier Transform techniques in the study of surface enhanced Raman spectra, Spectrochim. Acta, Vol. A46, 285-294.
• HOPE, G.A. and BROWN, G.A. (1994) In-situ additive monitoring during copper deposition in acid sulfate electrolyte, Proc. Int. Symp. Electrochemistry in Mineral and Metal Processing, (R. Woods, F.M. Doyle and P. Richardson, Eds.), PV 96-6, Electrochem. Soc., Pennington, NJ., pp. 429-438
• HOPE, G.A., WATLING, K. and WOODS, R. (2001a), A SERS spectroelectrochemical investigation of the interaction of isopropyl, isobutyl and isoamyl xanthates with silver, Colloids and Surfaces A, Vol. 178 157-166.
• HOPE, G.A., WATLING, K. and WOODS, R. (2001b), An electrochemical investigation of the suppression of silver dissolution in aqueous cyanide by 2-mercaptobenzothiazole, J. Appl. Electrochem. , Vol. 31, 703-709.
• HOPE, G.A., WOODS, R. and WATLING, K. (2001c), A spectroelectrochemical investigation of the influence of sodium diisobutyldithiophosphinate on silver dissolution in aqueous cyanide, J. Appl. Electrochem. Vol. 31, 1285-1291.
• JEFFREY, M.I. and RITCHIE, I.M. (2000), The leaching of gold in cyanide solution in the presence of impurities I. The effect of lead, J. Electrochem. Soc., Vol. 147 3257-3262.
• KAKOVSKY, I.A. (1957), Physicochemical properties of some flotation reagents and their salts with ions of heavy non-ferrous metals, Proc. 2nd Int. Congr. Surface Activity, Vol. IV, (J.H. Schulman, Ed.), Butterworth, London, pp. 225-237.
• KOWAL, A. and POMIANOWSKI, A. (1973), Cyclic voltammetry of ethyl xanthate on a natural copper sulphide electrode, J. Electroanal. Chem., Vol. 46, 411-420.
• LEGAULT, M., BLUM L. and HUCKABY, D.A. (1996), An extended hexagon model for Cu underpotential deposition on Au(III), J. Electronal. Chem., Vol. 409, 79-86.
• LI, J., ZHU, X. and WADSWORTH, M.E. (1993), Raman spectroscopy of natural and oxidized metal sulfides, EPD Congress, (J.P. Hager, Ed.) MME/AIME, Warrendale PA, pp.229-243.
• LI, J. and WADSWORTH, M.E. (1993), Raman spectroscopy of electrochemically oxidized pyrite and optimum conditions for sulfur formation, Hydrometallurgy: Fundamentals, Technology and Innovation, (J.B. Hiskey and G.W. Warren, Eds.) SME/AIME, Littleton, CO, pp.127-141.
• NIXON, J.C. (1957), Discussion, Proc. 2nd Int. Congr. Surface Activity, Butterworth, London, Vol. 3, p.369.
• POMIANOWSKI, A. (1967), Cyclic voltammetry in dilute solutions of potassium ethyl xanthate, Roczniki Chem., Vol. 41, 1125-1129.
• SHI, Z. and LIPKOWSKI, J. (1994), Coadsorption of Cu2+ and SO4 2- at the Au(111) electrode, J. Electroanal. Chem., Vol 365, 303-309.
• SZEGLOWSKI, Z., CZARNECKI, J., KOWAL, A. and POMIANOWSKI, A. (1977), Adsorption of potassium ethyl xanthate on a copper electrode surface, Trans. IMM, Vol. 86, C115-118.
• TURCOTTE, S.B., BENNER, R.E., RILEY, A.M., LI,J., WADSWORTH M.E. and BODILY, D.M. (1993), Surface analysis of electrochemically oxidized metal sulfides using Raman spectroscopy, J. Electroanal. Chem., Vol. 347, 195-205.
• WATANABE, M. UCHIDA H. and IKEDA, N. (1995), Electrochemical quartz crystal microbalance study of copper ad-atoms on gold and platinum electrodes Part I. Adsorption of anions in sulfuric acid, J. Electroanal. Chem., Vol. 380, 255-260.
• WEAVER, M.J. and WASILESKI, S.A. (2000) Electrochemical Surface Spectroscopy, The Electrochemical Society Interface. pp.34-36.
• WOODS, R. (1971) The oxidation of ethyl xanthate on platinum, gold, copper, and galena electrodes: relation to the mechanism of mineral flotation, J. Phys. Chem., Vol. 75, 354-362.
• WOODS, R. (1996) Chemisorption of thiols on metal and metal sulfides, Modern Aspects of Electrochemistry, No. 29, (Eds., J.O'M. Bockris, B.E. Conway and R.E. White), Plenum Press, NY, pp. 401-453.
• WOODS, R. and HOPE, G.A. (1998), Spectroelectrochemical investigations of the interaction of ethyl xanthate with copper, silver and gold: I. FT-Raman and NMR spectra of xanthate compounds, Colloids and Surfaces A, Vol. 137, 319-328.
• WOODS, R. and HOPE, G.A. (1999), A SERS spectroelectrochemical investigation of the interaction of O-isopropyl-N-ethylthionocarbamate with copper surfaces, Colloids and Surfaces A, Vol. 146, 63-74.
• WOODS, R., HOPE, G.A. and BROWN, G.M. (1998a), Spectroelectrochemical investigations of the interaction of ethyl xanthate with copper, silver and gold: II. SERS of xanthate adsorbed on silver and copper surfaces, Colloids and Surfaces A, Vol. 137, 329-337.
• WOODS, R., HOPE, G.A. and BROWN, G.M. (1998b), Spectroelectrochemical investigations of the interaction of ethyl xanthate with copper, silver and gold: III. SERS of xanthate adsorbed on gold surfaces, Colloids and Surfaces A, Vol. 137, 339-344.
• WOODS, R., HOPE, G.A. and WATLING, K. (2000), A SERS spectroelectrochemical investigation of the interaction of 2-mercaptobenzothiazole with copper, silver and gold surfaces, J. Appl. Electrochem., Vol. 30, 1209-1222.
• ZHU, X.; LI, J.; BODILY, D.M.; WADSWORTH, M.E. (1992), Tranpassive oxidation of pyrite, Proc. Int. Symp. Electrochemistry in Mineral and Metal Processing III, PV 92-17, (R. Woods and P.E. Richardson Eds.), Electrochem.Soc., Pennington, NJ., pp.391- 409.
• ZHU, X.; WADSWORTH, M.E.;. WOODS, R. (1997), Electrochemical kinetics of the anodic dissolution of nickel matte and synthetic Ni3S2, Nickel-Cobalt 97, Volume I: Hydrometallurgy and Refining of Nickel and Cobalt (W.C. Cooper and I. Mihaylov, Eds.) CIM, Canada, pp. 153-167.