Features of the Microstructure and Chemical Compositions of Vanadium-Containing Slags Including Determination of Vanadium Oxidation Degrees

Materials (Basel). 2019 Oct 31;12(21):3578. doi: 10.3390/ma12213578.

Abstract

Metallurgical vanadium-containing converter slag could be used as an alternative vanadium source. The development of a physico-chemical basis for the comprehensive processing of industrial vanadium-containing debris requires information about their elemental composition as well as the oxidation degrees of the elements and forms of compounds in order to solve two key problems: a better utilization of industrial wastes and a lowering of environment impact. This research was aimed at the development of methods to determine the fractions of elements and their oxidation degrees in vanadium-containing industrial debris exemplified by basic oxygen converter vanadium slags. A set of bulk and surface analysis methods (X-ray fluorescence analysis (XRF), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS)) was used for this purpose: based on results of elemental analysis, SEM detects the oxide phases of metals, while an analysis of the XPS lines' fine structures provides fractions of corresponding elements with definite oxidation degrees. In this way, one can determine the fractions of vanadium in multiple oxidation degrees in slags and can properly select the chemicals and parameters of chemical processes for its fullest extraction.

Keywords: X-ray fluorescence analysis (XRF); X-ray photoelectron spectroscopy (XPS); converter slag; extraction; oxidation degree; phase composition; scanning electron microscopy (SEM); vanadium.