A review on vanadium extraction techniques from major vanadium-containing resources

The critical role of vanadium in metallurgy and the increasing commercialization of vanadium redox flow batteries have contributed to a rise in market demand for vanadium,emphasizing the need to ensure the sustainability of vanadium production.Converter vanadium slag and stone coal,generated during the smelting process of vanadium–titanium magnetite,serve as primary raw materials for vanadium extraction.This paper reviews the process mineralogy of converter vanadium slag and stone coal,encompassing the chemical and physical phase compositions of the raw materials and the state of vanadium occurrence.The aim is to establish a theoretical foundation for the mechanistic study of the vanadium extraction techniques and to provide a reference for the optimization of the process afterward.This paper systematically summarizes the current vanadium extraction technology from converter vanadium slag,covering roasting,direct leaching,sub-molten salt method,and the technology and research status of vanadium extraction from stone coal.Most importantly,it identifies key issues in the current vanadium extraction techniques and challenges faced in actual production,based on the analysis of the current vanadium extraction process and mechanism research.The forward feasibility and prospects for the development of vanadium extraction technology are outlined.

Effect of Soda Ash on Properties of Mold Flux and Mineralogical Structures of Flux Film

During continuous casting,properties of mold flux and mineralogical structures of flux film play important roles in controlling steel quality.The effect of soda ash on the physical properties and crystallization characteristics of mold flux was investigated using process mineralogy,including polarizing microscopy,X-ray diffraction,and electron microprobe,etc.Mold flux was mainly prepared using cement clinker and industrial mineral materials under laboratory conditions,and the mineralogical structures of the flux film were systematically identified and quantitatively analyzed.The results showed that,by increasing the soda ash content from 10mass% to 18mass%,the crystallization temperature,critical cooling rate and crystallization ratio of the flux film decreased,but the crystallization ratio still reached 75% after adding soda ash,and the mineral compositions and microstructures of the flux film changed slightly.When the soda ash content exceeded 14mass%,the critical cooling rate and the crystallization ratio decreased slightly,whereas the mineral content of the flux film changed evidently,with a large amount of cuspidine precipitation and a significant decrease in the wollastonite content until it reached zero,which resulted in deterioration of the lubrication of the flux film.