The effect of ultrasonic pre-treatment on wettability and floatability of chalcopyrite, pyrite and quartz


The effect of ultrasonic pre-treatment on wettability and floatability of chalcopyrite, pyrite and quartz

Hassanzadehmahaleh, A.; van Hall, .; Öktem, A.; Özkan, G.; Rudolph, M.

Despite the four-decade study on ultrasound’s (US) impact on mineral’s floatabilities, there is still not a clear image regarding its role in mineral surface wettability. For this purpose, the current investigation endeavours the wettability and floatability characteristics of a chalcopyrite-pyrite-quartz (Cp-Py-Qtz) system in the presence and absence of an ultrasonic pre-treatment. The ultrasonic process was carried out by a Sonopuls at a constant frequency of 20 kHz with an adjustable power level from 30 to 200 W. Initially, impact of sonication time (15, 30, 45, 60 and 90 s as well as 10, 20 and 30 min) and power level (30, 60, 90, 120 and 180 W) were evaluated while the dissolved oxygen, temperature, conductivity and pH were monitored. Collector-less micro-flotation tests were carried out on the non-pre-treated and the US pre-treated samples at 60 W and 15 s. The samples’ hydrophobicities were determined by the drop shape analysis approach. The dissolved-oxygen level was varied using a mini bench pressurized water reactor to study the effect of O2(aq) concentration on the chalcopyrite and pyrite wettability characteristics. The results showed that the minerals’ hydrophilicities were relatively sensitive to the sonication’s time than its power that resulted in reducing all three minerals’ hydrophilicities. In addition, it was found that the dissolved oxygen content and creation of sub-micron sized bubbles led to an improvement on chalcopyrite and pyrite’ hydrophobicities. Finally, we proved that the Cp’s floatability increased and Qtz’s recovery reduced while being subjected to the ultrasonic irradiation (15 s at 60 W), however, Py’s recovery remained constant. This conclusion confirmed possibility of a selective separation in ultrasound-assisted copper ore flotation. We recommend further advanced investigations are highly required e.g. using an X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and atomic force microscopy (AFM) to profoundly understand the surface modification induced by the ultrasonication.

Keywords: Ultrasound; dissolved oxygen; floatability; chalcopyrite-pyrite-quartz system; contact angle

  • Contribution to proceedings
    IMPC 2020 - XXX International Mineral Processing Congress, 18.-22.10.2020, Cape Town, South Africa

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Publ.-Id: 30747