Novel Methods to Extract Vanadium from Vanadium Slag by Liquid Oxidation Technology

Abstract

A series of new green metallurgical processes have been proposed and developed to improve the recovery of vanadium and chromium in vanadium slag, and solve the environmental problems occurred in the traditional production process. The reactivity of three reaction media including sub-molten potassium hydroxide, sub-molten sodium hydroxide, and NaOH-NaNO 3 binary molten salt medium has been examined and compared. In comparison with the traditional sodium salt roasting technology, which operates at 850 °C, the operation temperature in the new media can drop to 200~450°C, significantly decreasing the energy consumption. Chemical conversion ratio of vanadium and chromium using the new reaction media could reach to above 95% and 80%, respectively, superior to the traditional technology. For in the latter technology the data is 80% for vanadium and only 10% for chromium. Thus, the application of such reaction media in the processing of vanadium slag has been proven to be feasible and attractive, and the processes developed based on such media are expected to replace the traditional roasting process in the near future.