Oxygen demand test-A diagnostic tool for determining the optimum aeration time in the selective separation of chalcopyrite/Pyrite mixed mineral systems
Date
2014
Authors
Owusu, C.
Skinner, W.
Fornasiero, D.
Addai Mensah, J.
Zanin, M.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Conference paper
Citation
XXVII International Mineral Processing Congress (IMPC 2014), 2014, pp.1-10
Statement of Responsibility
Conference Name
International Mineral Processing Congress (20 Oct 2014 - 24 Oct 2014 : Chile)
Abstract
This paper highlights the importance of pulp aeration in the selective separation of chalcopyrite from chalcopyrite/pyrite mixtures of varying pyrite content (20-80 wt.%). Laboratory batch flotation studies and oxygen demand tests were performed to predict the optimum amount of air required for the selective separation of chalcopyrite from pyrite. The pulp oxygen demand was shown to increase with increasing pyrite content but decrease with time as more air is introduced into the system. Complementary batch flotation tests showed significant improvement in chalcopyrite flotation under moderate pre-aeration of the pulp. However, a continuous decrease of chalcopyrite flotation was observed under highly aerated conditions. The amount of air required to achieve maximum chalcopyrite flotation recovery correlated positively with the mass fraction of pyrite in the pulps. The greater the wt.% of pyrite in the chalcopyrite/pyrite pulp, the longer the aeration time required. The optimum aeration time was established as the time before which the oxygen consumption rate constant reaches a bottom plateau. Surface analysis (XPS) indicated that the continuous decrease in pyrite recovery observed with increasing aeration time was due to the formation of more iron oxy/hydroxide on its surfaces, the same species accounting for the decrease in Cp recovery after prolonged aeration.