Extraction of vanadium oxide cpds from foundry slag - using dil phosphoric acid after preliminary oxidising roasting

摘要

Foundry slag is subjected to preliminery oxidising roasting opt. with addition of lime, and the finely comminuted (0.1 mm) product having the ratio V2O5:CaO 0.05 is leached with a 5-20 wt.% phosphoric acid soln. at 50-100 degrees C and a liquid:solid ratio of 2:1 to 10:1, for 30-120 mins. High degree of vanadium recovery is achieved (80-92%). The residue can be used as fertiliser.