New doctor has studied recovery of vanadium
26 October, 2017
On October 26th, at the Royal Institute of Technology (KTH), Department of Materials Science and Engineering, Mikael Lindvall defended his thesis, entitled "A Study on Vanadium Extraction from Fe-V-P Melts Derived from Primary and Secondary Sources".
Vanadium is an important alloying element that is used in the manufacture of, for example, high-strength steel and tool steel, as well as in the making of special alloys for the aerospace industry, batteries in energy storage systems and catalysts in the chemical and polymer industry. EU countries are dependent on the import of vanadium, and vanadium is now listed as a critical raw material. At the same time there are unused vanadium sources in Scandinavia, such as vanadium-rich steel slag in temporary storage at the steel sites, and primary sources like vanadium-bearing iron ore deposits. The amount of steel slag produced in Scandinavia each year alone contains vanadium corresponding to almost all of Europe’s total annual vanadium demand. Since this steel slag contains impurities such as phosphorus, there is a need to develop new extraction methods.
In a parallel project, metal melts have been produced by processing vanadium-bearing iron ore from Mustavaara, Finland, together with vanadium-rich steel slag, and by processing steel slag solely.
In his thesis, Mikael Lindvall has developed vanadium extraction methods for these metal melts, containing principally iron (Fe), vanadium (V) and phosphorus (P), into high-grade vanadium slags.
“The results of my studies have shown that it is possible to produce high-grade vanadium slags from these unused sources, which, via a conventional roast-leach method, can be converted to a high-grade vanadium alloy. The study also shows that the high-grade slag could be used directly to produce a vanadium alloy of lower grade. Processing of secondary sources rich in vanadium creates better economic incentives to exploit these sources”, says Mikael.
Experimental phase studies of high-grade vanadium slags have been conducted as a basis for the development works at KTH. Methods of producing these slags have been developed in semi-industrial-scale using a steel converter at Swerea MEFOS in Luleå.
“Mikael’s doctoral work has been extremely valuable for the advancement of research in process metallurgy, where he has contributed his considerable knowledge of slag metallurgy. We hope to be able to continue this successful collaboration,” says Professor Du Sichen, Mikael’s thesis supervisor.
Mikael started working as a research engineer at Swerea MEFOS in 2006, in the Department of Raw Materials and Research Development.