An environmentally-friendly technology of vanadium extraction from stone coal

A novel technology characterized by higher recovery of vanadium and which was environmentally-friendly was developed to recover vanadium from stone coal. Vanadium in stone coal could be leached by NaOH solution after roasting stone coal at 850 degrees C for 3 h. H(2)SO(4), Mg(NO(3))(2) and ammonia were employed, respectively, in two steps to remove the impurities of Si and Al from the leach liquor. After extracting vanadium from the leach liquor with 10 vol% N(235), 20 vol% secondary octyl alcohol and 70 vol% sulfonated kerosene, 1.5 mol/L NaOH was used as a stripping agent to strip vanadium from extracting solution. Adding 80 g/L NH(4)NO(3) to the stripping solution at 30-40 degrees C and pH 7.5, vanadium could be crystallized as ammonium metavanadate. Roasting ammonium metavanadate at 540 degrees C for 1 h, the purity Of V(2)O(5) met the standard specification. The total recovery of vanadium reached 67.39%, which was higher than the classical technology. (c) 2007 Elsevier Ltd. All rights reserved.