Tungsten is a rare metal with high melting point, which belongs to the periodic table of the elements in the sixth period (period second) of the group VIB. Tungsten is a silvery white metal, resembling the steel. Tungsten's high melting point, low vapor pressure, the evaporation rate is smaller. Very stable chemical properties of Tungsten at room temperature, not with air and water reaction, do not dissolve in hydrochloric acid, sulfuric acid, nitric acid and alkali solution. Aqua regia can only make the surface oxidation of mixed liquid, soluble in nitric acid and hydrofluoric acid. It can be combined with chlorine, bromine, iodine, carbon, nitrogen, sulfur and other high temperature, but not with hydrogen.
There are more than ten kinds of Tungsten, and there are two main types in China: the black Tungsten ore ( which is also named as wolframite), scheelite ( which is also named as calcium tungstate).
1. The black Tungsten ore: The chemical formular of the black Tungsten ore is (FeMn) WO4. The color of it is dark grey, reddish brown, light brown hair and brown and black, brown and other colors of iron. Semi metallic luster, metallic luster and resin. Usually the leaf shaped, curved flake, granular and dense; there are a thick plate, cylindrical tip, monoclinic crystal, often with white quartz together to form filling vein rock cracks in the granite and its nearby. The hardness of it is about 5 to 5.5, and the specific gravity of it is 7.1 to 7.5. Uneven. Brittle, weak magnetic. Wolframite is the main raw material for smelting Tungsten and manufacturing tungstic acid salts.
2. Scheelite: The chemical formular of it is MnWO4. The color of this kind of Tungsten is gray, brown, green and have pale red and so on. Oil sheen. It is affirmative system, false eight face body or plate-like crystals formed double cone shape, crystal face sometimes visible diagonal stripes, which are more common in twin lamella. Also some crystal is crusty, reniform, granular and dense block. 4.55 proportion 5.96.2 hardness. Brittle, shells or uneven. The fluorescent lights, scheelite can emit a beautiful light blue fluorescence. White Tungsten mineral in China's Jiangxi Dayu, Hunan Rucheng, Anhua, Linwu, Yunnan Wenshan. Multiple placer, Tungsten mineral used gravity (table above, jigging and so on.), flotation, chute, Amoy sand method get wolframite concentrate or white Tungsten concentrate.
There are more than ten kinds of Tungsten, and there are two main types in China: the black Tungsten ore ( which is also named as wolframite), scheelite ( which is also named as calcium tungstate).
1. The black Tungsten ore: The chemical formular of the black Tungsten ore is (FeMn) WO4. The color of it is dark grey, reddish brown, light brown hair and brown and black, brown and other colors of iron. Semi metallic luster, metallic luster and resin. Usually the leaf shaped, curved flake, granular and dense; there are a thick plate, cylindrical tip, monoclinic crystal, often with white quartz together to form filling vein rock cracks in the granite and its nearby. The hardness of it is about 5 to 5.5, and the specific gravity of it is 7.1 to 7.5. Uneven. Brittle, weak magnetic. Wolframite is the main raw material for smelting Tungsten and manufacturing tungstic acid salts.
2. Scheelite: The chemical formular of it is MnWO4. The color of this kind of Tungsten is gray, brown, green and have pale red and so on. Oil sheen. It is affirmative system, false eight face body or plate-like crystals formed double cone shape, crystal face sometimes visible diagonal stripes, which are more common in twin lamella. Also some crystal is crusty, reniform, granular and dense block. 4.55 proportion 5.96.2 hardness. Brittle, shells or uneven. The fluorescent lights, scheelite can emit a beautiful light blue fluorescence. White Tungsten mineral in China's Jiangxi Dayu, Hunan Rucheng, Anhua, Linwu, Yunnan Wenshan. Multiple placer, Tungsten mineral used gravity (table above, jigging and so on.), flotation, chute, Amoy sand method get wolframite concentrate or white Tungsten concentrate.