1. Extractive metallurgy

1.1 Minerals and ores

Tungsten, chemical symbol W, is a rare metal: its content in the earth's crust is estimated at 10 ^{– 6} by mass. Mineable mineral salts are scheelite CaWO ₄ and wolframite (Fe, Mn)WO ₄ [2][3] .

The average WO ₃ wolfram anhydride content of current mining projects is 0.4%. The most abundant deposits are in the countries of the Pacific Ring of Fire. The European contribution is small: Portugal, Spain, France (Salau, Ariège), Austria and Sweden. Soviet deposits are found...