Tungsten ores

• Mosten
• 1 June

Tungsten is a widely distributed element, almost all over the rocks, but the content is low. The ore deposit can be formed as commercial ore mining through the enrichment of relevant geological action. average content of tungsten in the crust is 1.3×10^-6, and in granite is 1.5×10^-6. Tungsten is a hexavalent cation in nature with a radius of 0.68×10^-10 m. since the W6 ion has small radius, high electricity price and strong polarization ability, it is easy to form complex anions, so tungsten mainly forms wolframite or scheelite precipitation in the form of complex anions [WO₄]2-, combined with cations such as Fe2、Mn2、Ca2 in solution. Tungsten ores are mainly divided into scheelite and scheelite. The wolframite is the most important ore for extracting tungsten, which is also called tungsten manganese iron ore. The wolframite is brown to black with metallic or semimetallic gloss. scheelite shape for granular stone, white with yellow, fat luster. Orange, double-cone crystal, large crystal, and the tip is transparent dark orange. symbiotic with calcite muscovite and black cassiterite, in which scheelite and calcite have fluorescence properties. heated or irradiated by ultraviolet light, slightly purple. is the main raw material for tungsten smelting.

The chemical composition of wolframite is (Fe,Mn) WO₄, and the crystal belongs to the oxide mineral of monoclinic system. Mineral and stripe colors vary with iron and manganese content, the more iron, the darker the color, generally brownish-red to black, stripe tan to dark brown, metallic luster to semi-metallic luster, there is a complete set of plate cleavage, specific gravity 7.1-7.5, Morse hardness 4.5-5.5, generally have weak magnetic. the crystal morphology is plate-like or columnar. wolframite is an intermediate member of FeWO-MnWO₄ class of homogeneous series. of this series, containing more than 80% of FeWO₄ or MnWO₄ molecules are called tungsten iron ore and tungsten manganese ore, respectively. The English famous source of wolframite is ancient German wolf( unpleasant) and ram( dross), which refers to the appearance of dross on the surface of tin melt when smelting tin containing black tungsten ore at that time, which affects smelting. Chemical compositions of scheelite：CaWO₄.

Since the W and Mo ion radii are almost equal, the W and Mo in scheelite are completely similar and become scheelite —— molybdenum tungsten series. The crystals belong to tetragonal tungstate minerals. The English name is named after C.W. Schiller (Scheele), the discoverer of tungstate in scheelite. Old name calcium tungsten ore or calcium tungstate ore. WO₃ content was 80.6%. It is the most important mineral of tungsten with wolframite. Tungsten in the composition can be partially replaced by molybdenum analogues.