Direct Reduction of Vanadium Oxide in Molten CaCl2

Abstract

A combined process of electrolysis of CaO in the molten CaCl 2 and of calciothermic reduction, so-called OS process, was applied to prepare metallic vanadium directly from V 2 O 3 . The fine metallic powder containing 1860 mass ppm oxygen was obtained using 0.5mol%CaO-CaCl 2 melt for 10.8 ks at 1173 K. The oxygen level did not decrease further even when twice electricity was applied. Because the metallic vanadium could be electrochemically deoxidized to the level of 10 ppm oxygen from 1.48 %, the large amount of by-product, CaO, due to reduction and the large surface area of the fine particles are the reasons of high oxygen content in the reduced powder.

Direct Reduction of Liquid V2O5 in Molten CaCl2

“…In our earlier study, vanadium metal was obtained from V 2 O 3 by OS process (3)(4)(5). However, vanadium is extracted as the most stable form of V 2 O 5 from the ore. For using V 2 O 3 as the starting material of electrolysis, V 2 O 3 should be prepared by using hydrogen reduction of V 2 O 5 .…”

Synthesis of Tantalum Powders in KBr−NaBr and KI−NaI Melts Using Electrochemical Pulverization

“…The most developed method for producing deposits of refractory metals is metallothermic reduction in the molten alkali and /or alkali earth halides. [7][8][9][10][11][12] It should be noted that the alkali and alkali earth metals are able to be dissolved in salt melts; moreover, they have a high reducing ability. The main disadvantage of the methods described in the studies [7][8][9][10][11][12] is the need for preliminary production of the reducing metal.…”

“…Deposits of various structure: dense solid, powdery, as well as dendritic ones, can be obtained by molten media electrolysis. The most developed method for producing deposits of refractory metals is metallothermic reduction in the molten alkali and /or alkali earth halides . It should be noted that the alkali and alkali earth metals are able to be dissolved in salt melts; moreover, they have a high reducing ability.…”

“…It should be noted that the alkali and alkali earth metals are able to be dissolved in salt melts; moreover, they have a high reducing ability. The main disadvantage of the methods described in the studies is the need for preliminary production of the reducing metal. Moreover, the particle size distribution of the obtained powders mainly depends on the size of the raw material (tantalum oxide).…”

Ni/NiO Reference Electrode Potential Measurements in Molten CaCl2–CaO

“…1,2 Due to the solubility and stability of oxide ions in molten CaCl 2 , it has been used for the reduction of a number of metal oxides, such as PuO 2 , 2,3 TiO 2 , 4 and V 2 O 5 . 5 These calciothermic reduction processes have been used in industrial and national security applications.…”