Ferrovanadium from a secondary source of vanadium
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literature. The present work as being described first deals with standardization of preparative procedure for iron vanadate using a synthetically prepared sodium vanadate solution. The information gathered from this primary investigation has next been taken as the basis for processing the sludge leached solution to recover the contained vanadium in the form of iron vanadate compounds of suitable composition. The final phase of work has been concerned with studies on the preparation of ferrovanadium from iron vanadate compound. A very much similar line of research dealing with molybdenum has been reported by the authors in a previous communication. 2 The reported work dealt with processing of a molybdenum bearing aqueous solution to result in recovery of molybdenum in the form of ferrimolybdate which was subsequently used for the preparation of powder and massive forms of ferromolybdenum by employing hydrogen and aluminothermic reduction methods, respectively.
Preparation of Ferrous Vanadate from Synthetic Solution. As has been stated, this portion of work essentially aimed for gathering knowledge on the preparation of ferrous vanadate for which a synthetic solution of vanadium was used. The studies were carried out using a vanadium beating solution containing 0.015 kg V205 per liter (prepared by dissolving in hot sodium hydroxide solution chemically pure V205) and ferrous sulfate solution containing 0.050 kg Fe 2+ per liter (prepared by dissolving in water analar grade FeSO4 9 7 HzO). The ferrous sulfate solution was taken in a burette from which a known amount was added to 0.1 liter solution of vanadium taken in a beaker. The mixture was kept stirred. The pH of the solution was continuously monitored and controlled at a desired point by addition of dilute solution of sodium hydroxide. The solution along with the precipitate in the beaker was stirred for a duration of two hours after which the precipitate was filtered out, washed, dried, and finally calcined at 773 K. The precipitate thus obtained was analyzed for vanadium and iron. The chemical formation of ferrous vanadate was assumed to take place according to the following reaction: 2 NaVO3 + n FeSO4 + 2(n - 1)NaOH---~ n FeO 9 V205 + n Na2SO4 + (n - 1)HzO
[1] where n stands for the mole ratio of FeO to V205. The value of n would depend upon the conditions used for precipitation. The results of experiments dealing with precipitation of ferrous vanadate from the synthetic vanadium solution are summarized in Table I. The first two experiments as recorded in Table I were carded out using in each case 100 pct theoretical FeSO4 (2 moles of FeSO4 to 1 mole of V205 based on Eq. [1]). The pH of the solution was 7 in one case and 9 in the other. Vanadium precipitated as 2 FeO 9 V205 type compound. The recovery amounted to 93 to 94 pct. The next experiment conducted with the same amount of FeSO4 but at a higher pH of 11 resulted in a drastic reduction of the recovery value to 76 pct. The value of n for the precipitated compound was found to be 3.1. In this case the quan
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