Types of tungsten

There are more than ten major tungsten deposits, and there are two main types in China: wolframite (tungstate of manganese and iron) and scheelite (calcium tungstate).
1. Wolframite (FeMn) WO4. The colours are dark gray, light reddish brown, light brown black, brown and iron brown. Semi-metallic luster, metal luster and resin luster. Usually, they are leaf-like, curved sheet-like, granular and compact, and some monoclinic crystals, such as thick plate-like, pointed column-like, are filled in the granite and its adjacent rock fissures in the form of veins together with white quartz. Hardness 5-5.5, specific gravity 7.1-7.5. Heterogeneous fracture. It is brittle and has weak magnetism. Wolframite is the main raw material for tungsten smelting and tungstate production. Alkali fusion is used in traditional process.
2. Scheelite CaWO4. The color is gray-white, but also yellow-brown, green and light red. Grease luster. It belongs to a cubic system and forms a bipyramidal pseudooctahedron or plate-like crystal. Oblique stripes can sometimes be seen on the crystal plane, of which the intercalated twins are more common. Some crystals are crustaceous, nephroid, granular and dense. Hardness 4.5-5; specific gravity 5.9-6.2. Brittle, shell-like or heterogeneous fracture. When illuminated by fluorescent lamp, scheelite can emit beautiful light blue fluorescence. Scheelite minerals are located in Dayu, Xiushui, Rucheng, Anhua, Linwu, Luanchuan, Henan, Wenshan, Yunnan and other places in China. More placer deposits,
The above tungsten minerals can be obtained from wolframite concentrate or Scheelite Concentrate by gravity separation (shaking table, jigging, etc.), flotation, chute and heavy sand removal.