Application of ultrasonic irradiation to micro-bubble flotation

Yang Geng, Natsuko Kuroki, Shuji Owada

    Research output: Chapter in Book/Report/Conference proceedingConference contribution


    Micro-bubble flotation is considered to be an ideal method for the separation of fine or ultra-fine particles, which are difficult to be separated with conventional flotation and other solid separation technologies. Micro-bubble flotation can increase the probability of bubble-particle collision more than conventional milli-bubble flotation. However, there are also some problems. For example, it is known that the rising velocity of micro-bubble is quite low; therefore, the flotation rate reduces. And also, the bubble-particle adhesion probability becomes lower than that of milli-bubble flotation, which is proved in our prior research. In this paper, we applied ultrasonic irradiation to the micro-bubble flotation system in order to solve the above problems and focused on the bubblebubble and bubble-particle interactions. For clarifying the behavior of bubble-bubble interaction, bubbles behavior was recorded by high-speed camera under irradiation of various ultrasonic frequencies. As a result, in the case of bubble-bubble interaction, it is proved that bubbles are highly coalesced by ultrasonic irradiation especially in the lower frequency and it can enhance more precise separation. In the case of bubble-particle behavior, it is found that the floatability become higher with the ultrasonic irradiation of higher frequency, and it is indicated that ultrasonic irradiation might improve the bubble-particle adhesion probability. Additionally, it is also found that the apparent CMC of the micro-bubble flotation under the ultrasonic field become much lower with higher frequency than with lower frequency, and it is suggested that the dramatic improvement of hydrophobization is achieved.

    Original languageEnglish
    Title of host publicationIMPC 2014 - 27th International Mineral Processing Congress
    Publication statusPublished - 2014
    Event27th International Mineral Processing Congress, IMPC 2014 - Santiago, Chile
    Duration: 2014 Oct 202014 Oct 24


    Other27th International Mineral Processing Congress, IMPC 2014

    ASJC Scopus subject areas

    • Earth-Surface Processes
    • Geochemistry and Petrology
    • Geotechnical Engineering and Engineering Geology
    • Mechanical Engineering


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