Microwave-assisted selective leaching of nickel from spent hydrodesulphurization catalyst: A comparative study between sulphuric and organic acids

• Type: Article in International Scientific Journal
• Date: 2013

Authors

ISS Pinto (Author) Other; Helena Soares (Author) FEUP

Journal

Title: Hydrometallurgy

Vol. 140

Pages: 20-27

ISSN: 0304-386X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 26 Citations

ISI Web of Science

Scopus - 34 Citations

Scientific classification

FOS: Engineering and technology

Other information

Authenticus ID: P-006-JM1

DOI: 10.1016/j.hydromet.2013.08.009

Abstract (EN): Hydrodesulphurization (HDS) spent catalysts are hazardous solid wastes from petroleum refining industries that contain valuable metals in appreciable concentrations. In this work, removal of Ni from a spent Ni-Mo catalyst was studied. In order to evaluate selective extraction of Ni from Al and Mo, ethylenediaminetetracetic acid (EDTA) leaching was performed using conventional and microwave-assisted methods and compared with the sulphuric acid (H2SO4) performance. Microwave-assisted leaching with nitrilotriacetic acid (NTA) solutions was also performed. Results showed that EDTA leaching, using conventional heating, had a very restricted Ni extraction, even when time and concentration were increased. When microwave-assisted process was applied, Ni dissolution reached 80% at optimum conditions (4 heating cycles of 60 s each, 0.1 M EDTA, pH 10.8 and S/L = 50 g/L). Even though this value was lower than the results obtained with 0.8 M H2SO4 (>= 90%), both Al and Mo extractions were significantly lower, leading to a more selective extraction. Ni leaching with NTA was not as efficient as EDTA, even though Mo and Al extractions were reduced.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8