English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The vanadium occurrence in stone coal, water leaching, and acid leaching residue was investigated by energy dispersive spectrometer (EDS) mapping and point analysis, and the vanadium transitions during roasting-leaching of stone coal were revealed. In the roasting process, vanadium-bearing muscovite is converted to K-Na-feldspar, accompanying the liberation of vanadium. Most liberated vanadium reacts with sodium salt to generate water-soluble sodium vanadate, some reacts with calcite in stone coal to form water-insoluble calcium vanadate, and other liberated vanadium exists as free vanadium oxide. However, for coarse muscovite grains, the reaction of muscovite converted to K-Na-feldspar only occurs at the outer margin of muscovite grains, and the vanadium in the interior of muscovite grains is not liberated. During water leaching, the sodium vanadate is leached out. The calcium vanadate and free vanadium oxide are dissolved out in the process of acid leaching, and the vanadium, presenting in muscovite grains surrounded by K-Na-feldspar, still remains in the acid leaching residue. Two suggestions, including optimization of grinding-classification process and adopting microwave roasting, were proposed for improving vanadium recovery according to the vanadium transition rules.

Vanadium Transitions during Roasting-Leaching Process of Vanadium Extraction from Stone Coal