Oxidation of sulfide-containing ores is the main cause of Acid Mine Drainage (AMD), which is an environmental problem associated with both the abandoned and active mines. Iron-bearing sulfide minerals can be oxidized and form mine waters with high sulfate content, low pH, high electrical conductivity, high redox potential, and high concentrations of iron, aluminum, and other heavy metals. In th...

Typomorphic features of placer gold the Anabar region were studied as predictive-exploration criteria. The target study was to determine typomorphic related intermediate sources (paleo-placers) and supposed nearby primary ore occurrences. Two varieties identified. first variety is well-rounded high-fineness lamellar with a highly modified internal structure. This native associated sources, Neog...

Recently, gold-carbenoid species have been proposed as intermediates in gold-catalyzed enyne rearrangements.1 Additionally, the reaction of gold complexes with propargyl esters has been developed as an alternative approach to metal carbenoids capable of effecting olefin cyclopropanation;2,3 however, to date, the reaction of electrophilic metals with alkynes has not been amenable to the generati...

Since the first gold liquid crystal was described in 1986, much effort has been done to prepare new compounds bearing this property. The review deals with the last results obtained in this new century. Gold(I) has a strong affinity to give linear co-ordination and metal-metal interactions, which produce a rich supramolecular chemistry, and can promote the behavior as liquid crystal. Therefore, ...

the mouteh refractory pyrite concentrates at pulp densities of 1.5%, 3%, 4.5% and 6% were treated, using thiobacillus ferrooxidans dsm 581 and the same bacteria adapted on the mouteh pyritic concentrate. compared with a non-adapted culture, use of an adapted inoculum of t. ferrooxidans increased bioleaching rate of iron by a factor of 1.940, 2.011, 1.859 and 1.559 for pulp densities 1.5%, 3%, 4...

First large-scale concentration of gold to ore grade in Earth’s crust took place at around 2.9 Ga quartz-pebble conglomerates, well before endogenous deposits, such as porphyry and epithermal systems or orogenic-type started play a significant role from ca. 2.75 onwards. The conglomerate-hosted placers, typified by those the Mesoarchaeaen Witwatersrand Basin South Africa, are thought have been ...