Automobile shredded residue valorisation by hydrometallurgical metal recovery.
The aim of this work was developing a hydrometallurgical process to recover metals from automobile shredded residue (or car fluff). Automobile shredded residue (ASR) was characterised by particle size distribution, total metal content and metal speciation in order to guide the choice of target metals and the operating conditions of leaching. Characterisation results showed that Fe is the most abundant metal in the waste, while Zn was the second abundant metal in the fraction with diameter lower than 500 μm. Sequential extractions denoted that Zn was easily extractable by weak acid attack, while Fe and Al required a strong acid attack to be removed. In order to recover zinc from <500 μm fraction leaching tests were operated using acetic acid, sulphuric acid and sodium hydroxide at different concentrations. Sulphuric acid determined the highest zinc extraction yield, while acetic acid determined the highest zinc extractive selectivity. Sodium hydroxide promoted an intermediate situation between sulphuric and acetic acid. Zn recovery by electro winning using acetic leach liquor determined 95% of Zn electro deposition yield in 1h, while using sulphuric leach liquor 40% yield in 1h and 50% yield in 2h were obtained. Simulation results showed that the sulphuric leaching process was more attractive than acetic leaching process.
Department of Chemistry, Sapienza University of Rome, Ple Aldo Moro 5, 00185 Rome, Italy.
Giuseppe
G
Granata
Emanuela
E
Moscardini
Giuliana
G
Furlani
Francesca
F
Pagnanelli
Luigi
L
Toro
D019342:Acetic Acid / Q000737:chemistry; D000143:Acids; D001336:Automobiles; D011232:Chemical Precipitation; D004563:Electrochemistry; D005240:Feasibility Studies; D007220:Industrial Waste / Q000032:analysis*; D008669:Metallurgy / Q000191:economics / Q000379:methods*; D008670:Metals / Q000737:chemistry / Q000302:isolation & purification*; D010316:Particle Size; D012972:Sodium Hydroxide / Q000737:chemistry; D012995:Solubility; D013464:Sulfuric Acids / Q000737:chemistry
D000143:Acids; D007220:Industrial Waste; D008670:Metals; D013464:Sulfuric Acids; D012972:Sodium Hydroxide; D019342:Acetic Acid