Recovery of Vanadium and Nickel from Heavy Oil Ash

Naganori Rokukawa
Research Institute for Green Technology, National Institute of
Advanced Industrial Science and Technology(AIST)
(16-1 Onogawa, Tsukuba-shi, Ibaraki, 305-8569 Japan)

Abstract
For the purpose of recoveing valuable metals from heavy oil ash, a process of recovering vanadium and nickel from heavy oil ash was developed. Learding from the ash collected from the electrostatic precipitator of power plants and the separation of metal ions from leach liquor were examined. The process mainly consists of leaching, solvent extraction and crystallization. Vanadium and nickel are leached by a hydrogen peroxide aqueous solution. Vanadium is extracted by a TOMAC-xylene solution followed by stripping to aqueous phase in an alkaline condition. Nickel is extracted by HNAPO-kerosene is an acid condition. Adding ethanol results in vanadium and nickel deposition separately.

Key words: heavy oil ash, vanadium, nickel, solvent extraction, crystallization