Simulation of a palladium extraction circuit

Du Toit, Zita (2006-12)

Thesis (MScEng)--University of Stellenbosch, 2006.

Thesis

ENGLISH ABSTRACT: Behaviour of palladium, platinum, copper, chloride anions, hydrogen cations, the l3-hydroxyoxime LIX 84-1 and the primary amine Primene JM-T during the extraction of Pd at the Anglo Platinum Precious Metals Refinery (PMR). The extractions of Pd, Pt and Cu into the organic phase were modelled as first-order reactions, with respect to the concentration of Pd, Pt and Cu in the aqueous phase, respectively. The movement of all other species are based on the stoichiometry of the three extraction reactions. Parameters found from literature and from previous experimental work by Johnson Matthey Technology Centre and Anglo Research (previously the Anglo Platinum Research Centre) generally describe the thermodynamic and kinetic behaviour of Pd extraction. Parameters for Pt and Cu co-extraction have been hypothesised and need to be confirmed through adequate experimental testwork. The model is fully functional and, upon completion of the simulation, all species' concentration profiles are produced. Eight mixers have been modelled as two continuous stirred tank reactors (CSTRs) with counter-current flow, and the concentration profiles are given as functions of the residence time of the two CSTRs. A secondary model has been created to facilitate future validation of the model by mimicking the movement of species in titanium unit cell batch extraction experiments. Both the primary and secondary models are based on identical thermodynamic and kinetic parameters for all reactions involved. Due to the fact that possibly inaccurate parameters were used in the construction of the Pd extraction model, the outputs shown serve to illustrate the value of the simulation model once all unknown parameters have been quantified through adequate experimental work. Keywords: Anglo Platinum, PMR, solvent extraction, kinetics, simulation.

AFRIKAANSE OPSOMMING: Model is met behulp van Matlab en Simulink ontwikkel om die beweging van palladium, platinum, koper, chloried- en waterstofione, die hidroksie-oksiem LIX 84-1 en die primere amien Primene JM-T tydens die ekstraksie van Pd by die Anglo Piatinum Precious Metals Refinery (PMR) te simuleer. Die ekstraksie van Pd, Pt and Cu na die organiese fase is gemodelleer as eerste-orde reaksies, met betrekking tot die konsentrasie van Pd, Pt en Cu in die water-fase, respektiewelik. Die beweging van alle ander chemiese spesies is gebaseer op die stoichiometrie van die drie ekstraksiereaksies. Parameters gevind uit literatuur en vanaf vorige eksperimentele werk, gedoen deur Johnson Matthey Tegnologiesentrum en Anglo Research (voorheen die Anglo Platinum Navorsingsentrum), beskryf die termodinamiese en kinetiese gedrag van elemente betrokke in Pd ekstraksie. Parameters vir pt en Cu ko-ekstraksie is aangeneem en hierdie waardes moet deur die nodige eksperimentele toetswerk bepaal word, alvorens dit in die model ingesluit word. Die model is ten volle funksioneel en, met die voltooiing van simulasies, word alle spesies se konsentrasies in die organiese en water-fase vertoon. Agt mengers is gemodelleer as twee kontinue gemengde-tenk reaktore waardeur die twee fases in teenoorgestelde rigtings vloei, en die konsentrasieprofiele van al die spesies word as funksies van die mengsel-verblyftyd in die twee reaktore gegee. 'n Sekondere model is ontwikkel om toekomstige validasie van die primere model te bewerkstellig. Waar die primere gebaseer is op die vloei-uitleg van die Pd ekstraksie-baan by PMR, is die sekondere model gebaseer op die toepaslike kondisies in toetswerk wat algemeen gedoen word in 'n titanium eenheids-ekstraksiesel. Beide die primere en sekondere modelle gebruik identiese termodinamiese en kinetiese parameters vir alle betrokke ekstraksiereaksies. Omdat moontlike onakkurate parameters in die simulasiemodel gebruik word, wys die uitsette van die model slegs die funksionaliteit wat die simulasie-model sal he sodra alle parameters deur die nodige eksperimentele toetswerk bepaal is. Sleutelwoorde: Anglo Platinum, PMR, ekstraksie, kinetika, simulasie.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/4779
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