PROCESS FOR RECOVERY OF VANADIUM-VALUES FROM FERROPHOSPHORUS

1369307 Recovery of vanadium UNION CARBIDE CORP 14 March 1972 [15 March 1971] 11741/72 Heading C1A Vanadium values are recovered from ferrophosphorus by (a) oxidizing particulated ferrophosphorus with an oxidant at a temperature and for a time period sufficient to substantially convert the phosphorus therein to phosphate, (b) adding and mixing an alkaline earth contributing material (e.g. calcium carbonate, calcium oxide, magnesium oxide, magnesium carbonate or a slag or ore containing one of these compounds) to said oxidized ferrophosphorus in a mole ratio of alkaline earth metal compound contained in said contributing material to oxidized ferrophosphorus of between 1 and 2, (c) adding to and mixing with the mixture prepared in (b) an alkali metal salt in an amount between 3% and 35% by weight based on the weight of the mixture of step (b), and (d) roasting the mixture of step (c) at between 700‹ and 1050‹ C. for at least 45 minutes and (e) leaching the roasted mixture with an aqueous solvent to dissolve the vanadium therein and (f) separating the vanadium values from the leach liquor of step (e). The ferrophosphorus may be oxidized by hearth, fluid bed, rotary kiln or flame oxidation and water may be added to the mixture of step (c) and the moistened mixture compressed prior to roasting.