The Richmond Mine at Iron Mountain, Shasta County, California, USA provides an excellent opportunity to study the chemical and biological controls on acid mine drainage ~AMD! generation in situ, and to identify key factors controlling solution chemistry. Here we integrate four years of field-based geochemical data with 16S rRNA gene clone libraries and rRNA probe-based studies of microbial popu...

The sulfur-bearing minerals which predominate in coal seams are the iron sulfide ores pyrite, marcasite, amorphous 'sulfur-balls', and less commonly the monosulfide pyrrhotite. Excluding pyrrhotite, all have the same ratio of sulfur to iron but have different crystalline properties. The amorphous structure is reported to be the most reactive due to its large surface area, followed by pyrrhotite...

this study investigates removing ash and pyrite sulphur from bitumen by column flotation process. central composite design (ccd) of response surface methodology (rsm) was applied for modeling and optimization of the percentage of ash and pyrite sulphur removal from bitumen. the effects of five parameters namely the amounts of collector and frother agents, particle size, wash water rate and feed...

The roasting of sulphide ores and concentrates is often the first step in the production of metals or chemicals. In many processes, the production of sulphuric acid is viewed as a by-product, while in some plants production is an important economic factor. Regardless of the purpose, a pyrite roasting plant consists of mainly three plant sections: roasting, gas cleaning and sulphuric acid. With ...

The title compound, [Fe(C(5)H(5))(C(7)H(5)Cl(2))], represents a versatile building block for the preparation of π-conjugated redox-active compounds or polymetallic organometallic systems due to the presence of the electrochemically active ferrocenyl unit. It is therefore a potential starting material for the preperation of the corresponding alkyne. In the crystal, the alkenyl unit and the cyclo...

in this research, a single-stage low-temperature hydrothermal synthesis route was successfully developed for preparation of iron disulfide. the prepared powder was characterized by x-ray diffraction (xrd) and scanning electron microscopy (sem). these analyses showed that nanoparticles were well crystallized, pyrite was the main product and the shape of crystals was nanorod. also, the influences...

Introduction: Although magnetite crystals in ALH84001 have received considerable attention in the literature as a potential biomarker, the sulfide component is important because the coexistence of magnetite and sulfides has also been suggested as a marker for past biogenic activity [1]. Very little research, however, has focused on the formation of sulfides in ALH84001. Early research on the su...

sulfur emission from coal combustion presents many environmental problems. the techniques used to reduce the amount of sulfur in coal before combustion, include physical, chemical and biological processes.biological processes based on degradation of sulfur compounds by microorganisms offer many advantages over the conventional physical and chemical processes. the processes are performed under m...

in this study, pyrite was produced by hydrothermal precipitation from the reaction between feso4 and na2s2o3 at high pressure and high temperature in a stirred reactor. the solid product was purified by means of solvent extraction to remove sulfur. powder was characterized by x-ray diffraction (xrd), scanning electron microscopy (sem) and thermal analyses. results indicated that pyrite was prod...