Tungsten recovery from alkaline leach solutions as synthetic scheelite

• Tipo: Artigo em Revista Científica Internacional
• Data: 2007

Autores

José Inácio Martins (Autor) FEUP; Lima, JLFC (Autor) FFUP; Moreira, A (Autor) Outra; Costa, SC (Autor) Outra

Revista

Título: Hydrometallurgy

Vol. 85

Páginas: 110-115

ISSN: 0304-386X

Editora: Elsevier

Indexação

ISI Web of Knowledge - 13 Citações

ISI Web of Science

Scopus - 22 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Outras ciências da engenharia e tecnologias

Outras Informações

ID Authenticus: P-004-BF8

DOI: 10.1016/j.hydromet.2006.08.007

Abstract (EN): The recovery of tungsten from alkaline leach solutions has been studied examining the effect of temperature, pH, Ca/WO3 molar ratio and nature of the precipitated calcium tungstate. The precipitation kinetics of calcium tungstate, upon the addition of aqueous sodium tungstate to calcium solutions, was followed by potentiometric measurements using a calcium ion-selective electrode. Two models, a crystal growth model and a second-order reaction opposed by zero-order reaction, have been used to test the experimental data. Both models show that the apparent activation energy of CaWO4 precipitation falls in the range 58 to 67 kJ mol(-1). The kinetic data shows that the maximum recovery of precipitated calcium tungstate occurs at pH >= 8.5 with a 10% excess of CaCl2 at 50 degrees C over a period of 20 min using sodium tungstate solutions of 100 g L-1 and 150 g L-1 WO3.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6