Design optimisation study of solvent extraction: chemical reaction, mass transfer and mixer–settler hydrodynamics

• Type: Article in International Scientific Journal
• Date: 2004

Authors

Gilberto A. Pinto (Author) Other; Fernando O. Durão (Author) Other; António Manuel Antunes Fiúza (Author) FEUP; Margarida M.B.L. Guimarães (Author) Other; Carlos Manuel Novais Madureira (Author) FEUP

Journal

Title: Hydrometallurgy

Vol. 74 No. 1

Pages: 131-147

ISSN: 0304-386X

Publisher: Elsevier

Indexing

ISI Web of Science

COMPENDEX

Scientific classification

FOS: Engineering and technology > Chemical engineering

CORDIS: Technological sciences > Engineering > Chemical engineering ; Technological sciences > Engineering > Civil engineering > Geotechnics

Other information

Abstract (EN): In this paper it is shown how the design of solvent extraction flow-sheets can be stated as a multicriterion optimisation problem, using the positive weighted sum approach not only to obtain parametric optimisation (i.e., the best operating conditions: agitation speed, residence time and phase flow ratio but also to help in structural optimisation (i.e., to synthesise the best process flow-sheet: number of stages, flow structure and phase recycle ratio. We demonstrate this over a case study, namely, the selective separation of two chemically akin (and hard to separate) metals, zinc and cadmium, commonly found together in the leaching liquor of complex ores. With this case study, it is shown that the design solutions are richer and more wide-ranging when put together from the vantage point of multicriterion optimization, whereas they become narrow-minded and/or biased if the starting point is a single criterion point of view. Three other conclusions (eventually of less general validity) were also obtained: (i) the opposite effects of feed phase flow-rates on recovery and purity, (ii) the high sensitivity of short optimum residence times to variations in agitation speed, (iii) the ability of counter-flow associations of a variable number of mixer-settler units accommodates changes in metal purity and overall recovery in response to drivers in market prices and environmental policies.

Language: Portuguese

Type (Professor's evaluation): Scientific

No. of pages: 17