In: Briggs D, Grant JT (eds) Surface analysis by Auger and X-ray photoelectron spectroscopy. Seah MP (2003) Quantification in AES and XPS. Rossi A, Elsener B (1992) Surf Interface Anal 18:499вЂ“504 Wiedmann JA, Steiff A, Weinspach PM (1980) Chem. Fifth European Conference on Mixing, pp 143вЂ“154, Wurzburg, Germany Nienow AW, Warmoeskerken GM, Smith JM, Konno M (1985) On the flooding/loading transition and the complete dispersal condition in aerated vessels agitated by a Rushton-turbine in Cranfield, Bedford, England: BHRA. Valenti P, Polidoro M, Buonfiglio V, Visca P, Orsi N (1990) J Gen Appl Microbiol 36:351 Silverman MP, Lundgren DG (1959) J Bacteriol 77:642 Hackl RP, Dreisinger DB, Peters E, King JA (1995) Hydrometallurgy 39:25вЂ“48 Zhang L, Qiu G, Hu Y, Sun X, Li J, Gu G (2008) Trans Non Ferrous Met Soc China 18:1415вЂ“1420ДЄsta MP, Cama J, Martinez M, GimГ©nez J (2009) J Hazard Mater 171:965вЂ“972 Sasaki K, Takatsugi K, Kaneko K, Kozai N, Ohnuki T, Tuovinen OH, Hirajima T (2010) Hydrometallurgy 104:424вЂ“431 Hansford GS, Vargas T (2001) Hydrometallurgy 59:135вЂ“145 Schippers A, Sand W (1999) Appl Environ Microbiol 65:319вЂ“321 Nesbitt HW, Muir IJ (1998) Mineral Petrol 62:123вЂ“144Д¬orkhill CI, Wincott PL, Lloyd JR, Vaughan DJ (2008) Geochim Cosmochim Acta 72:5616вЂ“5633 Xia J, Yang Y, He H, Zhao X, Liang C, Zheng L, Ma C, Zhao Y, Nie Z, Qiu G (2010) Hydrometallurgy 100:129вЂ“135 Tuovinen OH, Bhatti TB, Bigham JM, Hallberg KB, Garcia OJr, LindstrГ¶m EB (1994) Appl Environ Microbiol 60:3268вЂ“3274 Rossi A, Atzei D, Da Pelo S, Frau F, Lattanzi P, England KER, Vaughan DJ (2001) Surf Interface Anal 31:465ДЇantauzzi M, Atzei D, Elsener B, Lattanzi P, Rossi A (2006) Surf Interface Anal 38:922ДЇantauzzi M, Atzei D, Elsener B, Lattanzi P, Rossi A (2007) Surf Interface Anal 39:908Д®lsener B, Fantauzzi M, Atzei D, Rossi A (2007) Eur J Mineral 19:353ДЇantauzzi M, Rossi G, Elsener B, Atzei D, Loi G, Rossi A (2009) Anal Bioanal Chem 393:1931вЂ“1941 Rossi G (1971) Res Assoc Miner Sarda Iglesias 76:5вЂ“23, in Italian This was attributed to the deposition, on the mineral surfaces, of the remnants of a bio-film consisting of an extra-cellular polymer layer that had favoured the bacterial action. Evidence of microbial cells adhesion at mineral surfaces was also produced: carbon and nitrogen were revealed by CHNS, and nitrogen was also detected on the bioleached surfaces by XPS. On the surfaces of the mineral residue particles, elemental sulphur as reaction intermediate of the leaching process and precipitated secondary phases (FeвЂ“OOH and jarosite), together with adsorbed arsenates, was detected. After bioleaching, no signals of iron, arsenic and sulphur originating from pyrite and arsenopyrite were detected, confirming a strong oxidation and the dissolution of the particles. The chemical state of the main elements (Fe, As and S) at the surface of the bioreactor feed particles and of the residue after bioleaching was investigated by X-ray photoelectron and X-ray excited Auger electron spectroscopy. The flotation concentrate was a mixture of pyrite (FeS 2) and arsenopyrite (FeAsS) after bioleaching, 95% of the initial content of pyrite and 85% of arsenopyrite were dissolved. X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and X-ray-induced Auger electron spectroscopy mineral surfaces investigations, along with inductively coupled plasma-atomic emission spectroscopy and carbon, hydrogen, nitrogen and sulphur determination (CHNS) analyses, were carried out prior and after bioleaching. In this work, a multi-technical bulk and surface analytical approach was used to investigate the bioleaching of a pyrite and arsenopyrite flotation concentrate with a mixed microflora mainly consisting of Acidithiobacillus ferrooxidans.

Xps peak sulphur s2p