The ores of chromite, nickel, copper, and zinc show a wide distribution over geologic time, but those of iron, titanium, lead, uranium, gold, silver, molybdenum, tungsten, and tin are more restricted. Many of the limitations to specific time intervals are probably imposed by the evolving tectonic history of Earth interacting with the effects of the biomass on the evolution of the earth's s surf...

Scheelite is a calcium tungstate mineral (CaWO4) well known in the mining industry as a source of tungsten. This mineral fluoresces under shortwave UV and X-rays excitation with a characteristic blue luminescence centered at about 425 nm. CaWO4-based powder was commonly used as blue phosphor and scintillator (due to high Z of W) [1-3]. The emitted spectrum shifts to yellow in the presence of mo...

< 250 words) Although skarn ores are one of the largest metal resources in Europe, its processing is often challenging due to a very fine grained and intergrown mineralization. Other challenges have to be overcome if the valuable minerals are tungsten bearing minerals (i.e. scheelite or wolframite) due to their brittleness which requires to carefully design the beneficiation flowsheet in order ...

River water used to irrigate arable land in Dayu County, Jiangxi Province, China, is polluted with cadmium from tailings and the wastewater of tungsten ore dressing plants. From information about the date of construction of ore dressing plants and an analysis of the annual growth rings of trees, we deduced that local residents have been exposed to cadmium for at least 25 years. Cadmium exposure...