Abstract: The invention relates to a method for the extraction of vanadium from various sources in the form of vanadiumpentoxide, V2O5, from a source containing vanadium. The method includes the steps of: providing a source of V2O5, heating the source to a temperature of at least 1000° C., evaporating V2O5 from the heated source and recovering the evaporated V2O5.

Abstract: A rustproof austenitic cast steel part having tensile strength greater than 550 MPA and elongation at break over 30%, is characterised in that the cast steel having an aluminium content of 0 to 4% and a silicon content of 1 to 4% is within an alloying range that is determined by the coordinates of four points (Crequiv.=14; Niequiv.=8), (Crequiv.=14; Niequiv.=14), (Crequiv.=22; Niequiv.=8) and (Crequiv.=22 Niequiv.=16), wherein the chromium and nickel equivalents are calculated from the chemical composition of a cast steel using the relations (1) and (2): Cr equiv . = % ? ? Cr + % ? ? Mo + 1.5 ? % ? ? Si + 0.5 ? % ? ? W + 0.9 ? % ? ? Nb + 4 ? % ? ? A ? ? 1 + 4 ? % ? ? Ti + 1.5 ? % ? ? V + 0 ? .9 ? % ? ? Ta ( 1 ) Ni equiv . = % ? ? Ni + 30 ? % ? ? C + 18 ? % ? ? N + 0.5 ? % ? ? Mn + 0.3 ? % ? ? Co + 0.2 ? % ? ? Cu - 0.