Voltammetric and drift spectroscopy investigation in dithiophosphinate-chalcopyrite system

Guler T., Hicyilmaz C., Gokagac G., Ekmekci Z.

JOURNAL OF COLLOID AND INTERFACE SCIENCE, vol.279, no.1, pp.46-54, 2004 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 279 Issue: 1
  • Publication Date: 2004
  • Doi Number: 10.1016/j.jcis.2004.06.036
  • Journal Name: JOURNAL OF COLLOID AND INTERFACE SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.46-54
  • Keywords: chalcopyrite, dithiophosphinate, electrochemistry, cyclic voltammetry, DRIFT spectroscopy, SULFITE ION SYSTEM, SURFACE MODIFICATIONS, AEROPHINE 3418A, GOLD SURFACES, PYRITE, FLOTATION, COMPLEXES, COPPER, DIISOBUTYLDITHIOPHOSPHINATE, ELECTROCHEMISTRY
  • Middle East Technical University Affiliated: Yes

Abstract

The mechanism of dithiophosphinate (DTPI) adsorption on chalcopyrite was investigated by diffuse reflectance Fourier transformation (DRIFT) spectroscopy and by cyclic voltammetry (CV) at various pHs. CV experiments showed that the redox reactions occurred at a certain degree of irreversibility on the chalcopyrite surface in the absence of a collector due to preferential dissolution of iron ions in slightly acid solution and irreversible surface coverage by iron oxyhydroxides in neutral and alkaline solutions. In the presence of DTPI, CV experiments failed to identify the type of the adsorbed DTPI species and electrochemical processes occurring on chalcopyrite due to formation of an electrochemically passive surface layer preventing electron transfer. However, DRIFT spectroscopy tests showed this passive layer to be mainly CuDTPI + (DTPI)(2). Both CV and DRIFT spectroscopy established that the activity of collector species decreased with increasing pH due to formation of stable hydrophilic metal oxyhydroxides on the chalcopyrite surface. (C) 2004 Elsevier Inc. All rights reserved.