Study of the process of oxidizing-sodium roasting of industrial vanadium-containing ferrophosphorus and vanadium slags

Abstract

Among the alloying metals used in the smelting of high-quality steels, vanadium occupies a special place. Its introduction into steel, even in very small amounts (tenths and hundredths of a percent), provides significant improvement in the service properties of metal structures made from it. Global demand for vanadium ferroalloys exceeds its production. Lack of vanadium raw materials is the limiting factor for increasing production of ferrovanadium. Siliceous-carbonaceous ores of Karatau in Kazakhstan, amounting to more than four billion tons, are among the world's largest vanadium reserves. Although these ores contain up to 1% V 2 O 5 , they cannot be enriched, and there are no technologies for the rational vanadium extraction from them. This article presents the results of studies on the extraction of vanadium from ferrophosphorus, obtained during the complex processing of these ores together with phosphorites in the process of obtaining yellow phosphorus. The processes of oxidizingsodium roasting of industrial vanadium-containing ferrophosphorus (1.5 % V) and vanadium slag (10 % V 2 O 5 ) obtained during the converter processing of ferrophosphorus have been studied. It has been shown that watersoluble compound NaVO 3 is forming during oxidizing roasting of ferrophosphorus or slag in mixed with Na 2 CO 3 . With aqueous acid leaching of ferrophosphorus roasting cinder, vanadium extraction into solution is achieved up to 81 %, and with leaching of slag cake with Na 2 CO 3 -more than 92 %. Total V 2 O 5 extraction is 75 %.Mastering of the technology for processing phosphate and vanadium-containing siliceous raw materials at Kazphosphate LLP will expand the raw material base of vanadium and will allow creating a production facility for smelting more than 200 tpy of 50 % ferrovanadium.