Enhancing Fine Particle Recovery in Flotation and its Potential Application to the Environmental Desulphurization Process

Demers, Isabelle (2005). Enhancing Fine Particle Recovery in Flotation and its Potential Application to the Environmental Desulphurization Process. (Rapport ). Université du Québec en Abitibi-Témiscamingue. Repéré dans Depositum à https://depositum.uqat.ca/id/eprint/305

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Résumé

Environmental desulphurization was recently proposed as a possible method to
reduce the volume and mass of acid-generating tailings stored in tailings ponds. It
consists of separating the sulphide minerals (acid-generating) from the tailing stream
before its disposal in the tailings pond using a bulk sulphide flotation process. Studies
have shown lower recoveries for fine sulphide particles compared to coarse and
middle-sized particles, a problem also observed in other flotation applications. This
document addresses the following question: How can we improve fine pyrite and
pyrrhotite recovery in the environmental desulphurization process by flotation?
Two main approaches are used to improve the fine particle recovery in flotation; to
increase the particle size, or to decrease the bubble size. Particle size is increased
through several aggregation methods and the aggregated particles are then floated, a
process known as floc flotation. Aggregation can be induced by polymer flocculants,
hydrophobic interactions and micro-organisms.
Fine particles are best floated with small bubbles, and hydrodynamic conditions
inside a mechanical flotation cell are not suited for fine particle flotation. Flotation
columns of various types yield better fine particle recovery because of more
favourable conditions and smaller bubbles. The small bubbles can be generated via
dissolved-air flotation, induced-air flotation, hydrodynamic cavitation,
electroflotation and microbubble generators.
Most of the methods are irrelevant of the mineral type and surface state as long as the
mineral is hydrophobic, either naturally or made hydrophobic by surfactants.
Therefore, theoretically, they could be applied to sulphides (pyrite and pyrrhotite) in
environmental desulphurization. Suggestions are presented for future testwork in
environmental desulphurization, such as the use of flotation columns, contact cells or
Jameson cells, hydrophobic flocculation without oil enhancement, the use of fine
bubble generators and microbially-induced flocculation. However, polymer
flocculation, electroflotation, turbulent microflotation and the use of centrifugal force
field were not suggested for fine sulphide particle recovery in environmental
desulphurization.

Type de document:	Thèse ou mémoires (Rapport )
Directeur de mémoire/thèse:	Non, spécifié
Informations complémentaires:	Comprend un résumé en anglais seulement. Rapport de synthèse environnementale présenté comme exigence partielle du doctorat en sciences de l'environnement. Comprend des réf. bibliogr. (f. 39-46).
Mots-clés libres:	desulfuration particule flottation assainissement environnement
Divisions:	Forêts > Doctorat en sciences de l'environnement
Date de dépôt:	29 août 2012 13:04
Dernière modification:	21 févr. 2013 20:38
URI:	https://depositum.uqat.ca/id/eprint/305

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