Bacterial adhesion to mineral surfaces plays an important role not only in bacterial survival in natural ecosystems, but also in mining industry applications. Selective adhesion was investigated with Thiobacillus ferrooxidans by using four minerals, pyrite, quartz, chalcopyrite, and galena. Escherichia coli was used as a control bacterium. Contact angles were used as indicators of hydrophobicit...

The adsorption of Mycobacterium Phlei cells on the surfaces of pyrite and sphalerite was studied as functions of time and pH. The results indicated that a higher amount of cells adsorbing onto pyrite compared with that onto sphalerite under neutral and alkaline conditions, and it was also observed from photographs of scanning electron micrograph. To gain a better insight into the mechanisms of ...

The kinetics and mechanisms of dissolution of the major base metal sulphide minerals, pyrite, chalcopyrite, galena and sphalerite in acidic (chloride) media have been investigated. Minerals were ground in air, then dissolved in air-equilibrated solutions at pH 2.5, while monitoring the redox potential. Solution samples were analysed by ICP-AES and HPLC, and surfaces of residual sulphides analys...

Extensive horizons of pyritic shale occur in Mid-Proterozoic sediments of the eastern Belt basin, Montana, U.S.A. These pyritic shales are of striped appearance. Laminated pyrite beds alternate with non-pyritic shale beds. Laminated pyrite beds have wavy-crinkly internal laminae and are interpreted as mineralized microbial mats. Pyrite is essentially the only sulfide mineral in these shales. Py...

Authors Response to the Comments by Reviewer 3 General comments Reviewer’s Comment: The manuscript “Pyrite Oxidation under initially neutral pH conditions and in the presence of Acidithiobacillus ferrooxidans and micromolar hydrogen peroxide” submitted by Y. Man and C. Lin, is interesting in so far as the studies about this issue are relatively scarce. However, in my opinion, selected pyrite cu...

In the case of pyrite bioleaching by Leptospirillum ferrooxidans, an organism without sulfur-oxidizing capacity, besides the production of tetra- and pentathionate, a considerable accumulation of elemental sulfur occurred. A similar result was obtained for chemical oxidation assays with acidic, sterile iron(III) ion-containing solutions. In the case of Thiobacillus ferrooxidans, only slight amo...

Elevated arsenic concentrations have been observed in shallow groundwater in the Cold Lake-Beaver River Basin (CLBR) of Alberta. The geology of this area includes up to 200 m of unconsolidated glacial deposits, with six regional interglacial sand and gravel aquifers, underlain by marine shale. Arsenic concentrations in unconsolidated sediment samples ranged between 1 to 17 ppm. Mineralogical ch...

The origin in rocks of the common iron sulphides, pyrrhotine, Fe 1 xS and pyrite, FeS2 and their behaviour during geochemical processes is best considered using the simplified redox reaction: 2FeS ~-~ FeS2 + Fe 2 + + 2e . Thus pyrrhotine is more reduced than pyrite and is the stable iron sulphide formed from magmas except where relatively high oxygen fugacities result from falling pressure or h...

A novel, anaerobically grown microbial biofilm, scraped from the inner surface of a borehole, 1474 m below land surface within a South African, Witwatersrand gold mine, contains framboidal pyrite. Water flowing from the borehole had a temperature of 30.9 degrees C, a pH of 7.4, and an Eh of -50 mV. Examination of the biofilm using X-ray diffraction, field emission gun scanning electron microsco...