ACID LEACHING OF ZINC FROM ZNO / AL 2 O 3 CATALYST

In this study a simple process has been developed for zinc recovery from ZnO/Al2O3 catalyst in acidic milieu. The results have shown that a high dissolution efficiency of zinc was achieved with H2SO4 (2M) at ambient temperature with a liquid/solid ratio of 10/1 while alumina support was left unaffected. The dissolution of ZnO reached 81% in the first 4 hours. The rate of dissolution increased slowly after that and reached 90% after 24h. Leaching process was found to be controlled by diffusion through a product layer. After separation, alumina with high purity (99,5%) was obtained. Zinc was precipitated in leach liquor by pHcontrolled precipitation using sodium hydroxide. The resulting solid was purified and dried at 120°C. Zinc powder in the form of ZnO with 100% purity was produced with recovery efficiency of 72,2%.

[1]  T. Albanis,et al.  Photocatalytic oxidation of methyl parathion over TiO2 and ZnO suspensions , 2007 .

[2]  Jyh-Cherng Chen,et al.  Preparation and application of granular ZnO/Al2O3 catalyst for the removal of hazardous trichloroethylene. , 2007, Journal of hazardous materials.

[3]  L. O’Dell,et al.  A (27)Al MAS NMR study of a sol-gel produced alumina: Identification of the NMR parameters of the theta-Al(2)O(3) transition alumina phase. , 2007, Solid state nuclear magnetic resonance.

[4]  A. Araújo,et al.  Extraction and recovery of chromium from electroplating sludge. , 2006, Journal of hazardous materials.

[5]  Jinseong Kim,et al.  Enhanced Selective Leaching of Chromium from Radioactive Sludges , 2006 .

[6]  P. Dvořák,et al.  Hydrometallurgical recovery of zinc from hot dip galvanizing ash , 2005 .

[7]  Chun-I. Lin,et al.  Variations of Physical Properties of a Solid Sample Containing Spent ZnO Catalyst, Carbon and Calcium Carbonate in the Zinc Recovery Reaction , 2005 .

[8]  E. Stefanakos,et al.  Synthesis and characterization of photocatalytic TiO 2 -ZnFe 2 O 4 nanoparticles , 2005 .

[9]  E. Guibal,et al.  Pd and Pt recovery using chitosan gel beads. I. Influence of the drying process on diffusion properties , 2002 .

[10]  E. Meux,et al.  Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride. , 2002, Journal of hazardous materials.

[11]  Laurent Marcos.  Etude experimentale et modelisation du transfert du zinc et du plomb dans des milieux sableux modeles , 2001 .

[12]  Dr. Bhumika Das,et al.  Recovery of Iron Values from Iron Ore Slimes by Selective Magnetic Coating , 2000 .

[13]  Berrin Ziyadanogˇulları.  Recovery of Copper and Cobalt from Concentrate and Converter Slag , 2000 .

[14]  J. Yi,et al.  Zinc Ion Removal from Aqueous Solutions Using Modified Silica Impregnated with 2-Ethylhexyl 2-Ethylhexyl Phosphonic Acid , 2000 .

[15]  G. Poźniak,et al.  Recovery and Concentration of Metal Ions. IV. Uphill Transport of Zn(II) in a Multimembrane Hybrid System , 1999 .

[16]  S. Kim,et al.  The effect of alkali metal salts on ZnOα-Al2O3 and MnO2 catalysts for the oxidative coupling of methane , 1997 .

[17]  L. Erickson,et al.  Reducing the formation of carbon oxides in the production of C2 hydrocarbons from methane , 1995 .

[18]  A. Gupta,et al.  Investigation into the ion exchange of the cyanide complexes of zinc(2+), cadmium(2+), and copper(1+) ions , 1987 .