Recovery of molybdates from an alkaline leachate of spent hydrodesulphurisation catalyst - proposal of a nearly-closed process

• Tipo: Artigo em Revista Científica Internacional
• Data: 2013

Autores

Isabel S.S.Pinto (Autor) Outra; Helena Soares (Autor) FEUP

Revista

Título: Journal of Cleaner Production

Vol. 52

Páginas: 481-487

ISSN: 0959-6526

Editora: Elsevier

Indexação

ISI Web of Knowledge - 22 Citações

ISI Web of Science

Scopus - 32 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias

CORDIS: Ciências Tecnológicas

Outras Informações

ID Authenticus: P-006-8XX

DOI: 10.1016/j.jclepro.2013.03.021

Abstract (EN): In this work, we developed a simple, effective, low-cost and more environmentally friendly process (with low energy requirements and minimized effluent emissions) to recover molybdenum from an alkaline leaching solution of a spent hydrodesulphurisation catalyst, as a final product with high purity and in high yield. Alkaline leaching of spent Ni-Mo hydrodesulphurisation catalysts results in a solution that mainly contains molybdenum and aluminum. Before recovering molybdenum, previous separation of aluminum from the solution, as a precipitate of aluminum hydroxide, was performed by lowering the pH to 8, at room temperature, with a yield of 99.2%. Recovery of molybdenum was studied by precipitation in the form of a salt of strontium or lead molybdate. The first process allowed a recovery of 96% of Mo at 25 degrees C, as tetragonal SrMoO4, with high purity (99%). Precipitation with lead at 25 degrees C resulted in a maximum recovery of 99.8% of the molybdenum, as tetragonal PbMoO4, with a purity of 99.5%. Finally, the destination of the final solution is discussed and a flow sheet considering the production of strontium/lead molybdate is proposed.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7