Method for preparing sigma-phase FeV50

The invention belongs to the field of metallurgy and relates to a method for preparing sigma-phase FeV50. The technical problem to the solved of the invention is to provide a method for preparing the sigma-phase FeV50 which has good apparent mass and is easy to break. In the adopted technical scheme, the sigma-phase FeV50 is obtained by uniformly mixing vanadium oxide, aluminum, iron and lime serving as raw materials, feeding the mixture into a furnace and smelting the mixture in an electric arc furnace by an electro-aluminothermic process. The method comprises the following steps of: a, adding excess aluminum into the raw materials while proportioning so as to reduce the vanadium oxide, melting a furnace charge down, depleting slag until vanadium content is low and removing lean slag; and b, adding an appropriate amount of vanadium oxide into alloy liquor from which the slag is removed to remove the excess aluminum, discharging and casting when the temperature and aluminum content of the alloy liquor meet requirements and cooling so as to obtain a product, namely, the sigma-phase FeV50. The crush strength of the sigma-phase FeV50 produced by the process is less than 510 MPa and convenience can be brought to vanadium iron manufacturers and customers in the crushing, sampling and using processes of vanadium iron.