Sulfide is an important pollutant in aqueous systems. Sulfide removal from polluted waters is required prior to discharge. Red mud (RM) is a solid waste of bauxite processing that is rich in reactive iron oxides and consequently has the potential to be used to remove sulfide from aqueous systems. A series of experiments was undertaken using raw and sintered RM to remove sulfide from waters. RM ...

introduction worldwide, ni-cu and pge magmatic sulfide deposits are confined to the lower parts of stratiform mafic and ultramafic complexes. however, ophiolite mafic and ultramafic complexes have been rarely explored for sulfide deposits despite the fact that they have been extensively explored and exploited for chromite. sulfide saturation during magmatic evolution is necessary for sulfide mi...

Biomining is the use of microorganisms to extract metals from sulfide and/or iron-containing ores and mineral concentrates. The iron and sulfide is microbially oxidized to produce ferric iron and sulfuric acid, and these chemicals convert the insoluble sulfides of metals such as copper, nickel and zinc to soluble metal sulfates that can be readily recovered from solution. Although gold is inert...

The formation of marine phosphatic mineral deposits remains incompletely understood, despite decades of research. The involvement of bacteria in this process has long been suspected, and both modern and ancient associations between bacteria and phosphorites have been recorded. Only recently has a specific bacterial metabolic process associated with the formation of phosphorites been discovered....

Magmatic sulfide deposits are the most significant source of platinum-group elements (PGE) in the world. Key to understanding their genesis is determining the processes and timing of sulfide saturation, metal enrichment and crustal contamination. In this study, we have identified droplets of magmatic sulfide from the Platreef, South Africa, where droplets of sulfide have been trapped in the ear...

Anoxic bottom water from Mono Lake, California, can biologically reduce added arsenate without any addition of electron donors. Of the possible in situ inorganic electron donors present, only sulfide was sufficiently abundant to drive this reaction. We tested the ability of sulfide to serve as an electron donor for arsenate reduction in experiments with lake water. Reduction of arsenate to arse...

Scientists from the U.S. Geological Survey are evaluating the potential for undiscovered sulfide deposits containing varying amounts of nickel, copper, platinumgroup metals, and cobalt in the Lake Superior region as part of an ongoing effort to assess the mineral potential of the United States. Similarities between rocks of the Midcontinent rift and rocks that host the Voisey Bay nickel-copper-...

A hydrogen gas (H(2))-producing strain of Ectothiorhodospira vacuolata isolated from Soap Lake, Washington, possessed nitrogenase activity. Increasing evolution of H(2) with decreasing ammonium chloride concentrations provided evidence that nitrogenase was the catalyst in gas production. Cells were grown in a mineral medium plus 0.2% acetate with sodium sulfide as an electron donor. Factors inc...