A review of recovery technologies of rare and rare earth metals from wastes generated in titanium and magnesium production

Abstract

It is acknowledged that titanium and magnesium production wastes pollute the environment, which in the sequence they create an environmental hazard for soils, groundwater and vegetation. Meanwhile, these wastes can be considered secondary resources of rare and rare earth metals. In recent years, the processing of industrial waste has been a new trend for the extraction of rare and rare earth metals, which can partially cover the demand in case of their disposal. This article is devoted to a review of the available literature and articles on the extraction of rare metals from titanium-magnesium production waste using various processing methods. Methods of their utilization are discussed with an emphasis on the extraction of rare and rare earth metals. This review considered waste processing technologies of various pyrometallurgical and hydrometallurgical processes. Technological schemes of various leaching and extraction processes were presented to give a holistic view of waste processing and extraction of rare metals contained in them. In general, the article contains an overview of the works published on the extraction of rare metals, such as REE (rare earth elements), niobium, tantalum and vanadium.

Overview of Technologies Used to Extract Scandium from Secondary Raw Materials

“…Scandium extraction is carried out with a 70% solution of tributyl phosphate in kerosene; the resulting scandium-enriched organic phase is washed from impurities with strong hydrochloric acid (220-240 g/l HCl); then the scandium extract is transferred to the aqueous phase (reextract) with a 7% hydrochloric acid solution. From the reextraction of oxalic acid, oxalates of scandium and other metals are precipitated, the resulting pulp is filtered, a solid precipitate of oxalates is dried and heated at 700ºc and a technical oxide containing 40-60% Sc2O3 is obtained [ [24], [25]].…”