The National University of Science and Technology (MISiS) has announced that its research team developed a new technology using spent vanadium catalysts (SVC) of sulphuric acid production as a secondary source of vanadium. MISiS has worked on this project with Belarusian State Technological University and the Institute of General and Inorganic Chemistry (National Academy of Sciences of Belarus).
During the production of sulphuric acid, about 40,000 tonnes of SVC arise annually worldwide. Since it contains 5–10 weight per cent vanadium, above that of other sources of vanadium-containing waste, SVC becomes one of the preferable secondary raw materials for vanadium extraction. Extraction from converter slag – currently the primary source of vanadium – is, on the other hand, more costly and less environmentally friendly. The evaluated capital cost of the technology is about 120–125 k$ (as opposed to 300 k$ using the existing method), the payback period is not more than one year.
Valentin Romanovski, one of the research authors, notes that using the MISiS technology provides 98 % of vanadium recovery.
"The multi-step method we have developed to obtain high-purity vanadium from SVC includes grinding, magnetic separation of iron and two-step leaching of vanadium. The first step — vanadium leaching in sulphuric acid solutions, ultrasonic treatment; the second step — reductive leaching in sodium sulphite solutions; finally — extraction of vanadium at temperature 80–90 °С using ammonium persulphate as an oxidiser," says Elena Romanovskaia, a senior researcher at Belarusian State Technological University.
There is an increasing industrial interest in vanadium applications in Russia, with the steel industry being the largest consumer of vanadium. The metal is also widely used in the aerospace, defence, power industries and car manufacturing.
Let us recall that SibFU's researchers, joined by colleagues from RUSAL, have improved the strength and malleability of aluminium-magnesium alloys by adding scandium, making them thus available for use in shipbuilding and automobile production.
