استفاده از روش فروشويي زيستي در سميت زدايي و بازيابي فلزات ارزشمند از كاتاليزگرهاي مستعمل

Application Of Bioleaching Technology In Detoxification And Recovery Of Valuable Metals From Spent Catalysts

Spent hydroprocessing catalysts are classified as hazardous waste by the US EPA. Several alternative methods such as disposal in landfills, regeneration/rejuvenation and reuse, utilization as raw materials to produce other useful products, and recovery of metals by hydrometallurgy and pyrometallurgy. are available to the refiners to deal with the spent catalyst problem. Hydroprocessing spent catalysts contain appreciable concentrations of metals such as Mo, Co, W, V. Ni and Al, which are used extensively in the steel industry and in the manufacture of special alloys. In the view of the environmental and economic benefits, increasing attention has been paid to develop processes for recovering metals from spent hydroprocessing catalyst. The existing recovery methods are often costiy and are associated with negative environmental impact. Bioleaching which is a green technology offers a novel approach for metal recovery from various solids. Bioleaching is based on the ability of microorganisms to transform solid compounds into soluble and extractable elements which can subsequently be recovered. This article is a review on the existing methods for management of spent catalyst and the researches which have been done in the Held of bioleaching of spent catalysts.