Vanadium Recovery from Oil Refinery Sludge Using Emulsion Membrane Technique

Cleaning of raw oil tanks produced huge quantities of oil sludge which is a potentially hazardous waste product. In order to reduce the environmental impact due to land disposal of this sludge and to valorize this waste material, many researches in the world pay considerable attention to removal of heavy metals from oil sludge. The aim of this work was to investigate Emulsion Liquid Membrane (ELM) technique for vanadium recovery from oil refinery sludge in two stages. The process involves contact of fly ash of this sludge with a sulfuric acid solution followed by purification and enrichment with ELM process. The experimental data illustrated that more than 65% of vanadium in fly ash can be extracted in one stage of leaching by sulfuric acid (96%) with liquid volume ratio to solid weight 0.1 l/g at 65oC. Under the optimum operating conditions of ELM technique, more than 86% of vanadium was extracted in 1 hr at ambient temperature. It was found that ELM technique could be effectively used in the recovery of different metals from oil refinery sludge.