Justifying size-by-size flotation rate distributions from size-by-association kinetic responses

• Published in: Powder technology Vol. 395; pp. 168 - 182
• Main Authors: Vinnett, L., Grammatikopoulos, T., El-Menshawy, A.H., Waters, K.E.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-01-2022; Elsevier BV
• Subjects: Chalcopyrite; Flotation; Flotation kinetics; Flotation rate distribution; Galena; Gamma distribution; QEMSCAN; Rate constants; Size-by-association; Flotation rate distribution; Gamma distribution; Flotation kinetics; Size-by-association; QEMSCAN
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2021.09.042

A size-by-association kinetic characterization for galena-chalcopyrite flotation is presented. The size-by-size maximum recovery R∞ and flotation rate distribution f(k) are first estimated by least-squares estimation (LSE) in four size classes. Gamma f(k)s are assumed in all cases. LSE is also used in the association categories subject to constraints to match/approach the size-by-size R∞-f(k)s pairs from the association classes. The methodology allows the size-by-size f(k)s to be explained from the size-by-association f(k)s. These size-by-association f(k)s do not converge to deterministic rate constants, which agree with the effect of other particle properties on the flotation response. The f(k)s in the −20 μm class are approximately 80–85% justified by liberated particles. These particles explain the fast-floating material in all size classes. Binary and complex middlings typically concentrate to slower flotation rates. From the f(k) results, slow-rate fractions are estimated from a low f(k) percentile. These fractions are not consistently attributed to complex middlings.
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•The size-by-size flotation rate distributions f(k)s were fractioned by association.•Liberated particles defined more than 85% of f(k) in the −20 μm class.•Liberated particles defined the f(k) tails (fast components) in the +20 μm class.•Binary and complex middlings were concentrated in slower flotation rates.•The size-by-association f(k)s did not consistently lead to single rate constants.